vides the principal arterial supply to the lower limb distal to the superficial veins are the long and short saphenous veins; their numer-
inguinal ligament and the gluteal fold (Figs 78.4–78.5). The femoral ous tributaries are mostly unnamed; however, changes in clinical prac-
artery courses within the subsartorial (adductor) canal, which is tice are driving a revision of the terminology. For further reading, see
located on the anteromedial aspect of the thigh. It passes through the Caggiati et al (2002, 2005). The long saphenous vein can be harvested
adductor hiatus to become the popliteal artery on entering the post- and used as a graft for peripheral vascular surgery, including coronary
erior compartment of the thigh and soon thereafter divides into the artery bypass (Kosinski 1926).
anterior and posterior tibial arteries. The obturator and inferior gluteal Deep veins of the lower limbs accompany the arteries and their
vessels also contribute to the supply of the proximal part of the limb. branches. Plantar digital veins arise from plexuses in the plantar regions
In the embryo, the inferior gluteal artery supplied the main axial artery of the toes, connect with dorsal digital veins and unite to form four
of the limb, which is represented in the adult by the artery to the plantar metatarsal veins. These run in the intermetatarsal spaces and
sciatic nerve. connect with dorsal veins by means of perforating veins. They then
The bones of the lower limb receive their arterial supply from nutri- connect with each other to constitute a deep plantar venous arch adja-
ent vessels, metaphysial arterial branches of the peri-articular anasto- cent to the deep plantar arch. From this venous arch, medial and lateral
moses, and the arteries supplying the muscles that attach to their plantar veins run near the corresponding arteries; they communicate
periosteum. The pattern of arterial supply is particularly relevant to with the long and short saphenous veins before forming the posterior
fracture healing, the spread of infection and malignancy, and the plan- tibial veins posterior to the medial malleolus. The posterior tibial veins
ning of reconstructive surgical procedures. For further details, consult accompany the posterior tibial artery. They receive veins from the calf


Cormack and Lamberty (1984), Taylor and Razaboni (1994) and Crock muscles, especially the venous plexus in soleus, and connect with super-
(1996). ficial veins and with the fibular veins. The latter, running with their
Ischaemia of the lower limb due to peripheral vascular disease is a artery, receive tributaries from soleus and from superficial veins.
tremendous burden on healthcare resources. Many diseases contribute The anterior tibial veins are continuations of the venae comitantes
to this pathology and include diabetes, hypertension and atherosclero- of the dorsalis pedis artery. They leave the extensor region between the
sis. Obesity and smoking also increase the risk of developing peripheral tibia and fibula, pass through the proximal end of the interosseous
vascular disease. Symptoms include intermittent claudication and membrane, and unite with the posterior tibial veins, at the distal border
wounds that do not heal well. Physical examination of such patients of popliteus, to form the popliteal vein.


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NOITCES
A B
Aorta External iliac artery
Common iliac artery Deep circumflex iliac artery
Internal iliac artery
Inferior epigastric artery Superior gluteal artery
Superficial circumflex iliac artery Inferior gluteal artery
External pudendal artery
Obturator artery Profunda femoris artery Lateral circumflex Medial circumflex femoral artery
femoral artery
Medial circumflex femoral artery Lateral circumflex femoral artery Profunda femoris artery
Femoral artery
Femoral artery
Perforating arteries Perforating arteries
Descending genicular artery
Popliteal artery Descending branch Site of hiatus in adductor magnus
Superior lateral genicular artery
Superior medial genicular artery
Superior medial genicular artery
Superior lateral genicular artery
Popliteal artery
Inferior lateral genicular artery Inferior lateral
genicular artery
Inferior medial genicular artery Inferior medial genicular artery
Anterior tibial artery
Anterior tibial recurrent artery
Fibular artery Posterior tibial artery
Anterior tibial artery
Perforating branch of
fibular artery
Perforating branch
Medial malleolar artery
Lateral malleolar network
Dorsalis pedis artery
Lateral tarsal artery
Medial tarsal artery Medial plantar artery
Arcuate artery Lateral plantar artery
Deep plantar branch Plantar arch
Deep branch of
First dorsal metatarsal artery Plantar metatarsal artery
dorsalis pedis artery
Dorsal digital arteries Plantar digital arteries
Fig . 78 .4 An overview of the arteries of the lower limb . A, Anterior aspect . B, Posterior aspect .
Venous (muscle) pumps in the connecting veins between the long saphenous vein and femoral
vein in the adductor canal may predispose to superficial varicosities
along the medial aspect of the thigh (Dodd and Cockett 1976).
While standing, venous return from the lower limb depends largely on
muscular activity, especially contraction of the calf and foot muscles,
venous plexuses
known as the ‘muscle pump’, whose efficiency is aided by the tight


sleeve of deep fascia (Ricci 2011). ‘Perforating’ veins connect the long Venous plexuses may be intramuscular (soleus) or intermuscular (in the
saphenous vein with the deep veins, particularly near the ankle, distal foot and gluteal region). The plexuses communicate with the axially
calf and knee. Their valves are arranged so as to prevent flow of blood running deep veins and are components of the ‘muscle pump’
from the deep to the superficial veins. At rest, pressure in a superficial mechanism.
vein is equal to the height of the column of blood extending from that
vein to the heart. When the posterior leg muscles contract, blood is
pumped proximally into the deep veins and is normally prevented from LYMPHATIC DRAINAGE
flowing into the superficial veins by the valves in the perforating veins.
During muscular relaxation, blood is drawn into the deep veins from Most lymph from the lower limb traverses a large intermediary inguinal
the superficial veins. If the valves in the perforating veins become group of nodes (Fig. 78.10). Peripheral nodes are few and all are deeply
incompetent, these veins become sites of ‘high-pressure leaks’ during sited. Except for an inconsistent node lying proximally on the interos-
muscular contraction, and the superficial veins become dilated and seous membrane near the anterior tibial vessels, they occur only in the
varicose. Similar perforating connections occur in the anterolateral popliteal fossa. Enlarged popliteal nodes may be palpated along the
region, where varicosities may also occur. Incompetence of the valves line of the popliteal vessels while the passively supported knee is


Innervation
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RETPAHC
Posterior Anterior gradually moved from extension to semi-flexion. These are often due
Superficial epigastric artery to inflammation, malignancy or injury to the lateral side of the foot.
Inguinal lymph nodes are found superficial and deep to the deep fascia.
Superior gluteal artery Superficial circumflex iliac artery
The deep nodes are few and lie alongside the medial aspect of the
Inferior gluteal artery Superficial external pudendal artery femoral vein. The superficial nodes may be divided into a lower vertical
group that clothe the proximal part of the long saphenous vein, and an
Obturator and profunda Femoral artery upper group that lie parallel to, but below, the inguinal ligament and
femoris arteries which are related laterally to the superficial circumflex iliac and medi-
Deep external pudendal artery
Inferior gluteal artery ally to the superficial external pudendal vessels. Lymph from the lower
Lateral circumflex femoral artery limb passes from the inguinal lymph nodes to the external and common
iliac nodes, and ultimately drains to the lateral aortic nodes. Deep
Obturator and profunda
Perforating arteries
femoris arteries gluteal lymph reaches the same group through the internal and common
iliac lymphatic vessels.
Femoral artery
Popliteal artery
Lateral genicular arteries Superficial tissues
Sural arteries Medial genicular arteries
The superficial lymph vessels begin in subcutaneous plexuses. Collect-
Popliteal artery Descending genicular artery
ing vessels leave the foot medially, along the long saphenous vein, or
Fibular artery Anterior tibial artery laterally with the short saphenous vein. Medial vessels are larger and
more numerous; they start on the medial side of the dorsum of the
Posterior tibial artery foot, ascend anterior or posterior to the medial malleolus and accom-
Posterior tibial artery
pany the long saphenous vein. They drain to the distal superficial
Fibular artery
inguinal nodes. Lateral vessels begin on the fibular side of the dorsum
Dorsalis pedis artery
Dorsalis pedis artery of the foot; some cross anteromedially in the leg to join the medial
Lateral plantar artery


vessels and so pass to the distal superficial inguinal lymph nodes, while
Medial plantar artery
others accompany the short saphenous vein and drain to the popliteal
nodes. Superficial lymph vessels from the gluteal region run anteriorly
Fig . 78 .5 The anatomical territories served by the cutaneous blood supply
to the proximal superficial inguinal nodes.
to the lower limb .
Deeper tissues
The deep lymph vessels accompany the anterior and posterior tibial,
fibular, popliteal and femoral vessels. Popliteal nodes interrupt the deep
vessels from the foot and leg; those from the thigh pass to the deep
Subfascial plexus inguinal nodes. The deep lymphatic vessels of the gluteal region follow
their corresponding blood vessels. Those accompanying the superior
gluteal vessels end in a node near the intrapelvic part of the superior
gluteal artery, adjacent to the superior border of the greater sciatic
foramen, while those that follow the inferior gluteal vessels traverse one
Fascial feeder or two of the small nodes inferior to piriformis and then pass to the
internal iliac nodes.
Suprafascial plexus
Intrafascial plexus INNERVATION
Direct cutaneous perforator
OVERVIEW OF THE LUMBAR
Fascia
AND SACRAL PLEXUSES
Periosteocutaneous perforator
Nerves derived from the lumbar and sacral plexuses innervate the lower
Bone limb (Fig. 78.11). The lumbar plexus lies deep within psoas major,
anterior to the transverse processes of the first three lumbar vertebrae.
The sacral plexus lies in the pelvis on the anterior surface of piriformis,
external to the pelvic fascia, which separates it from the inferior gluteal
Intercompartmental perforator and internal pudendal vessels. The lumbosacral trunk (L4 and L5)
emerges medial to psoas major on the posterior abdominal wall and
lies on the ala of the sacrum before crossing the pelvic brim to join the
Musculocutaneous perforator ventral ramus of S1. Contributions to the lumbosacral trunk may also
be derived from the third lumbar nerve (Bergman et al 1988).
Muscle


Septocutaneous perforator Lesions of the lumbar and sacral plexuses
Neurocutaneous perforator The deep and protected situation of the plexuses means that lesions are
Nerve not common. The lumbar plexus may be involved in retroperitoneal
pathology, and the sacral plexus may be invaded by pelvic malignancies.
Tendocutaneous perforator Both may be involved in the reticuloses, affected by plexiform neuro-
mas, or damaged in fractures of the lumbar spine and pelvis or in other
conditions that cause severe retroperitoneal and pelvic haemorrhage.
Tendon
Temporary lesions may occur after pregnancy and childbirth, e.g. after
difficult forceps delivery of a large baby. Pain, which may be diffuse, is
the most common feature.
Sciatica is pain in the lower back and hip region, which radiates
Venocutaneous perforator inferiorly along the posterior thigh to the leg. It is often caused by a
herniated intervertebral disc, compressing the L5 or S1 ventral rami.
The so-called piriformis syndrome, which may result from a variant or
Vein
anomalous relationship between piriformis and the sciatic nerve, may
also produce hip pain that radiates inferiorly along the course of the
Fig . 78 .6 Types of arterial perforators . sciatic nerve.


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9
NOITCES
A B
Aorta External iliac artery
Common iliac artery Deep circumflex iliac artery
Internal iliac artery
Inferior epigastric artery Superior gluteal artery
Superficial circumflex iliac artery Inferior gluteal artery
External pudendal artery
Obturator artery
Profunda femoris artery Medial circumflex femoral artery
Lateral circumflex
Medial circumflex femoral artery Lateral circumflex femoral artery femoral artery
Profunda femoris artery
Femoral artery
Perforating arteries Perforating arteries Femoral artery
Descending genicular artery
Popliteal artery Descending branch Site of hiatus in adductor magnus
Superior lateral genicular artery
Superior medial genicular artery
Superior medial genicular artery
Superior lateral genicular artery
Popliteal artery
Inferior lateral genicular artery Inferior lateral
genicular artery
Inferior medial genicular artery Inferior medial genicular artery
Anterior tibial artery
Anterior tibial recurrent artery
Fibular artery Posterior tibial artery
Anterior tibial artery
Perforating branch of fibular
artery
Perforating branch
Medial malleolar artery
Lateral malleolar network
Dorsalis pedis artery
Lateral tarsal artery
Medial tarsal artery Medial plantar artery
Arcuate artery Lateral plantar artery
Deep plantar branch
Plantar arch
Deep plantar artery
First dorsal metatarsal artery Plantar metatarsal artery
Dorsal digital arteries Plantar digital arteries
Perforator
Fig . 78 .7 The source and location of the arterial perforators of the lower limb . A, Anterior aspect . B, Posterior aspect .
OVERVIEW OF THE PRINCIPAL NERVES Obturator nerve (L2–4)
OF THE LOWER LIMB
The obturator nerve is the nerve of the medial compartment of the
Femoral nerve (L2–4)
thigh. It arises from the anterior divisions of the second to fourth
lumbar ventral rami, descends through psoas major and emerges from
The femoral nerve is the nerve of the anterior compartment of the thigh. its medial border at the pelvic brim. It crosses the sacroiliac joint


It arises from the posterior divisions of the second to fourth lumbar behind the common iliac artery and lateral to the internal iliac vessels,
ventral rami, descends through psoas major and emerges on its lateral runs along the lateral pelvic wall medial to obturator internus, and
border to pass between it and iliacus. It enters the thigh behind the enters the thigh through the upper part of the obturator foramen.
inguinal ligament and lateral to the femoral sheath. Its terminal Near the foramen, it divides into anterior and posterior branches,
branches form in the femoral triangle about 2 cm distal to the inguinal which are separated at first by part of obturator externus and more
ligament. In the abdomen, the nerve supplies small branches to iliacus distally by adductor brevis. It provides articular branches to the hip
and a branch to the proximal part of the femoral artery. It subsequently and knee, and may supply skin on the medial thigh and leg. The
supplies a large cutaneous area on the anterior and medial thigh, obturator nerve is described in detail on page 1372. An accessory
medial leg and foot, and gives articular branches to the hip, knee and obturator nerve may also be present and leaves the pelvis anterior to
ankle. The femoral nerve is described in detail on page 1372. the pubis.


Innervation
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RETPAHC
A
Inferior vena cava Superficial circumflex iliac vein
Common iliac vein
Superficial epigastric vein
Internal iliac vein External iliac vein Saphenous opening, lateral edge
Superficial epigastric vein
Superficial circumflex Femoral vein
iliac vein
Superficial external Superficial external pudendal vein
pudendal vein
Femoral vein
Profunda femoris vein
Long saphenous vein
Long saphenous
vein
B
Popliteal vein
Popliteal vein
Deep fascia
Saphenous nerve
Venae comitantes of posterior Short saphenous vein
and anterior tibial arteries
Short saphenous vein
Sural communicating
Long saphenous vein
branch
Sural nerve
Dorsal venous arch
Superficial veins
Deep veins
Sural nerve
Fig . 78 .8 An overview of the veins of the lower limb .
Dorsal venous arch
Sciatic nerve (L4, L5, S1–3)
The sciatic nerve travels in the posterior compartment of the thigh and,
via its major branches, supplies the leg and foot. Formed in the pelvis
from the ventral rami of the fourth lumbar to third sacral spinal nerves,
it is typically 2 cm wide at its origin and is the thickest nerve in the
body. It enters the lower limb via the greater sciatic foramen inferior to
piriformis and descends between the greater trochanter and ischial
tuberosity. In its descent along the posterior thigh, it is crossed by the Fig . 78 .9 A, The long saphenous vein and its tributaries . B, The short
long head of biceps femoris and divides into the tibial and common saphenous vein and its tributaries .
fibular (peroneal) nerves proximal to the knee; however, the level of
bifurcation can be variable. Prior to diverging, the tibial and common
fibular nerves are structurally separate and only loosely held together
as the sciatic nerve. The tibial nerve is derived from the anterior divi- but not the short head of biceps femoris, are supplied by the medial


sions of the sacral plexus, and the common fibular nerve is made up of (tibial) component of the sciatic nerve. The short head of biceps femoris
the posterior divisions of the plexus. The sciatic nerve sends articular is supplied by the lateral (common fibular) component. The common
branches to the hip joint through its posterior capsule (these are some- variations of the sciatic nerve have been well described and have been
times derived directly from the sacral plexus) and to the knee joint. The classified into six types (Beason and Anson 1937). The sciatic nerve is
posterior thigh muscles, including the ischial part of adductor magnus described in detail on page 1373.


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NOITCES
the anterior and lateral compartments. It descends obliquely along the
lateral side of the popliteal fossa to the fibular head, lying between the
tendon of biceps femoris and the lateral head of gastrocnemius; it then
curves lateral to the neck of the fibula, lying on the bone deep to fibu-
laris longus, and divides into superficial and deep fibular (peroneal)
nerves. Before it divides, it gives branches to the knee and superior
External iliac nodes
tibiofibular joints, and to the skin. The cutaneous area supplied by the
common fibular nerve and its terminal branches includes the antero-
lateral leg and most of the dorsum of the foot. The common fibular
nerve is described in detail on page 1415.
Deep inguinal nodes
Gluteal nerves (L4, L5, S1, S2)
Superficial inguinal nodes
The gluteal nerves arise from the posterior divisions of the sacral plexus.
The superior gluteal nerve (L4, L5, S1) leaves the pelvis through the
greater sciatic foramen superior to piriformis and supplies gluteus
medius, gluteus minimus, tensor fasciae latae and the hip joint. The
inferior gluteal nerve (L5, S1, S2) passes through the greater sciatic
foramen inferior to piriformis and supplies gluteus maximus. The
gluteal nerves are described in detail on page 1374.
CUTANEOUS INNERVATION
The cutaneous nerves supplying the skin of the lower limb are all
branches of the lumbar and sacral plexuses, with the exception of some
proximal nerves. The areas of distribution and spinal segments of origin
of the cutaneous nerves of the lower limb are illustrated in Figure
78.12. Variations in the composition and course of the cutaneous
Popliteal node
nerves of the lower limb are common.
Dermatomes
Our knowledge of the extent of individual dermatomes, especially in
the limbs, is largely based on clinical evidence (Ladak et al 2014). The


dermatomes of the lower limb are innervated by spinal nerves T12 to
S3 (see Fig. 78.12; Figs 78.13–78.14).
AUTONOMIC INNERVATION
Superficial lymphatics
The autonomic nerve supply to the limbs is exclusively sympathetic.
Deep lymphatics
Preganglionic sympathetic fibres to the lower limb are derived from
Direction of lymph flow neurones in the lateral horn of the lower thoracic (T10, T11 and T12)
and upper lumbar (L1, L2) spinal cord segments. Fibres pass in white
rami communicantes to the sympathetic trunk and synapse in the
lumbar and sacral ganglia. Postganglionic fibres pass in grey rami com-
municantes to enter the lumbar and sacral plexuses; many are distrib-
uted to the skin via the cutaneous branches of the nerves derived from
these plexuses. The blood vessels to the lower limb receive their sym-
pathetic nerve supply via adjacent peripheral nerves. Postganglionic
fibres accompanying the iliac arteries are destined mainly for the pelvis
but may supply vessels in the proximal thigh.
Fig . 78 .10 An overview of the lymphatics of the lower limb .
MOVEMENTS, MUSCLES AND
SEGMENTAL INNERVATION
Tibial nerve (L4, L5, S1–3)
Most limb muscles are innervated by neurones derived from more than
The tibial nerve is derived from the anterior divisions of the sacral one segment of the spinal cord. The predominant segmental origin of
plexus. It descends along the posterior thigh and popliteal fossa to the the nerve supply for each of the muscles of the lower limb and for the
distal border of popliteus, then passes anterior to the soleus with the movements that take place at the joints of the lower limb is summarized
popliteal artery and continues into the leg. In the popliteal fossa, it lies in Tables 78.1–78.4 (Sharrard 1955).
lateral to the popliteal vessels, becomes superficial to them at the knee
and crosses to the medial side of the artery. In the leg, it is the nerve of Movements At the central nervous level of control, muscles are not
the posterior compartment and descends with the posterior tibial


recognized as individual actuators but as components of movement,
vessels to lie between the heel and the medial malleolus. It ends deep
and may therefore contribute to several types of motion, acting vari-
to the flexor retinaculum by dividing into the medial and lateral plantar
ously as prime movers, antagonists, fixators or synergists. Some muscles
nerves. The tibial nerve supplies articular branches to the knee and
have been included in more than one place in Table 78.3 on the basis
ankle joints. Its cutaneous supply, including its terminal branches, sup-
that a muscle that acts across one joint can produce a combination of
plies the back of the calf, the sole, the lateral border of the foot and the
movements (e.g. flexion with medial rotation, or extension with adduc-
medial and lateral sides of the heel. The tibial nerve is described in
tion) and a muscle that crosses two joints can produce more than one
detail on page 1415.
movement. It is also important to remember that these listings are not
exhaustive.
Common fibular nerve (L4, L5, S1, S2)
Spinal nerves There is no universal consensus concerning the con-
The common fibular nerve (common peroneal nerve) is derived from tribution that individual spinal nerves make to the innervation of indi-
the posterior divisions of the sacral plexus. In the leg, it is the nerve of vidual muscles; the most positive identifications, which are limited,


87
RETPAHC
Pelvic girdle and lower limb: overview and surface anatomy
For example, the ilioinguinal and iliohypogastric nerves may arise malleolus and the medial side of the foot and hallux. The postaxial
from a common trunk or the ilioinguinal nerve may be absent. The border starts in the gluteal region and descends to the centre of the
ilioinguinal nerve may also join the iliohypogastric nerve at the iliac popliteal fossa, then deviates laterally to the lateral malleolus and the
crest. When the obturator nerve makes a more significant contribution lateral side of the foot. The ventral and dorsal axial lines exhibit cor-
to the cutaneous innervation, the medial cutaneous branch of the responding obliquity. The ventral axial line starts proximally at the
femoral nerve is relatively small. Alternatively, the cutaneous branch of medial end of the inguinal ligament and descends along the postero-
the obturator nerve may be absent. The lateral femoral cutaneous nerve medial aspect of the thigh and leg to end proximal to the heel. The
normally arises from L2 and L3, but L1 may also contribute. Although dorsal axial line begins in the lateral gluteal region and descends pos-
it usually bifurcates after it exits the pelvis, it may bifurcate within the terolaterally in the thigh to the knee; it inclines medially and ends
pelvic cavity. The nerve may be absent on one side and/or may be proximal to the ankle. Considerable overlap exists between adjacent
replaced by the ilioinguinal nerve or a branch of the anterior femoral dermatomes innervated by nerves derived from consecutive spinal cord
cutaneous nerve. The genital and femoral branches of the genitofemoral segments.
nerve may arise as separate offshoots of the lumbar plexus. The genital Surgical or chemical lumbar sympathectomy may be indicated in
branch may receive fibres from the twelfth thoracic nerve or may be arterial disease and in the management of plantar hyperhidrosis, and
completely absent, while the femoral branch may have an extensive may be used to treat rest pain or other troublesome sensory symptoms
distribution to the skin of the upper two-thirds of the thigh. The sural of arterial disease or in causalgia. A segment of the sympathetic trunk


nerve is subject to wide variation and may supply the dorsal cutaneous including the second and third lumbar ganglia is removed; preservation
aspect of the lateral two-and-a-half toes, or may terminate in the foot of the first lumbar ganglion is said to lessen the risk of ejaculatory
without any digital branches. problems.
The preaxial border starts near the midpoint of the thigh and
descends to the knee. It then curves medially, descending to the medial
Table 78.1 Segmental innervation of the muscles of the lower limb Table 78.2 Segmental innervation of joint movements of the lower limb
Segment Muscles supplied Region Muscles supplied Segment
L1 Psoas major, psoas minor Hip Flexors, adductors, medial rotators L1–3
L2 Psoas major, iliacus, sartorius, gracilis, pectineus, adductor longus, adductor Extensors, abductors, lateral rotators L5, S1
brevis Knee Extensors L3, 4
L3 Psoas major, quadriceps femoris, adductors (magnus, longus, brevis) Flexors L5, S1
L4 Psoas major, quadriceps femoris, tensor fasciae latae, adductor magnus, Ankle Dorsiflexors L4, 5
obturator externus, tibialis anterior, tibialis posterior Plantar flexors S1, 2
L5 Gluteus medius, gluteus minimus, obturator internus, semimembranosus, Foot Invertors L4, 5
semitendinosus, extensor hallucis longus, extensor digitorum longus, fibularis Evertors L5, S1
tertius, popliteus Intrinsic muscles S2, 3
S1 Gluteus maximus, obturator internus, piriformis, biceps femoris, semitendinosus,
popliteus, gastrocnemius, soleus, fibularis longus and fibularis brevis, extensor
digitorum brevis
S2 Piriformis, biceps femoris, gastrocnemius, soleus, flexor digitorum longus, flexor
hallucis longus, some intrinsic foot muscles


S3 Some intrinsic foot muscles (except abductor hallucis, flexor hallucis brevis,
flexor digitorum brevis, extensor digitorum brevis)
1324.e1


9
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Table 78.3 Movements, muscles and segmental innervation in the lower limb*
Joint Movement Muscle Innervation L1 L2 L3 L4 L5 S1 S2 S3
HIP FLEXION Psoas major Spinal nn. L1–3
Iliacus Femoral n.
Pectineus Femoral n. or accessory obturator n.
Rectus femoris Femoral n.
Adductor longus Obturator n.
Sartorius Femoral n.
EXTENSION Gluteus maximus Inferior gluteal n.
Adductor magnus Obturator and tibial nn.
Semitendinosus, semimembranosus, biceps femoris Tibial and common fibular nn.
MEDIAL ROTATION Iliacus Femoral n.
Gluteus medius and minimus Superior gluteal n.
Tensor fasciae latae Superior gluteal n.
LATERAL ROTATION Superior and inferior gemelli Nerve to obturator internus and nerve to quadratus
femoris, respectively
Quadratus femoris Nerve to quadratus femoris
Piriformis Nerve to piriformis
Obturator internus Nerve to obturator internus
Obturator externus Obturator n.
Sartorius Femoral n.
ADDUCTION Gracilis Obturator n.
Adductor longus Obturator n.
Adductor magnus Obturator and tibial nn.
Adductor brevis Obturator n.
Pectineus Femoral n. or accessory obturator n.
ABDUCTION Tensor fasciae latae Superior gluteal n.
Gluteus medius and minimus Superior gluteal n.
Piriformis Nerve to piriformis
KNEE FLEXION Semimembranosus Tibial n.
Semitendinosus Tibial n.
Biceps femoris Tibial and common fibular nn.
Gastrocnemius Tibial n.
EXTENSION Quadriceps femoris:
Rectus femoris Femoral n.
Vastus lateralis Femoral n.
Vastus intermedius Femoral n.
Vastus medialis Femoral n.
ANKLE DORSIFLEXION Tibialis anterior Deep fibular n.
Extensor digitorum longus Deep fibular n.


Extensor hallucis longus Deep fibular n.
Fibularis tertius Deep fibular n.
PLANTAR FLEXION Gastrocnemius Tibial n.
Soleus Tibial n.
Flexor digitorum longus Tibial n.
Flexor hallucis longus Tibial n.
Fibularis longus Superficial fibular n.
Tibialis posterior Tibial n.
INVERSION Tibialis anterior Deep fibular n.
Tibialis posterior Tibial n.
EVERSION Fibularis longus Superficial fibular n.
Fibularis tertius Deep fibular n.
Fibularis brevis Superficial fibular n.
TOES FLEXION Flexor digitorum longus Tibial n.
Flexor hallucis longus Tibial n.
Flexor hallucis brevis Medial plantar n.
Flexor digitorum brevis Medial plantar n.
Flexor accessorius (quadratus plantae) Lateral plantar n.
Flexor digiti minimi brevis Lateral plantar n.
Abductor hallucis Medial plantar n.
Abductor digiti minimi Lateral plantar n.
Lumbricals Medial and lateral plantar nn.
EXTENSION Extensor digitorum longus Deep fibular n.
Extensor hallucis longus Deep fibular n.
Extensor digitorum brevis Deep fibular n.
ABDUCTION Abductor hallucis Medial plantar n.
Abductor digiti minimi Lateral plantar n.
Dorsal interossei Lateral plantar n.
ADDUCTION Plantar interossei Lateral plantar n.
Adductor hallucis Lateral plantar n.
*Royal blue shading denotes nerve roots from which there is a known dominant contribution. Turquoise shading denotes nerve roots from which the contribution is of similar degree.
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Table 78.4 The movements and muscles tested to determine the location of a lesion in the lower limb
Movement Muscle Upper motor neurone* Spinal nerve level Reflex Nerve
Hip flexion Iliopsoas ++ L1, 2 Femoral
Hip adduction Adductors + L2, 3 (+) Obturator
Hip extension Gluteus maximus L5, S1 Inferior gluteal
Knee flexion Hamstrings + S1 Sciatic
Knee extension Quadriceps femoris L3, 4 ++ Femoral
Ankle dorsiflexion Tibialis anterior ++ L4 Deep fibular
Ankle eversion Fibularis longus and fibularis brevis L5, S1 Superficial fibular
Ankle inversion Tibialis posterior L4, 5 Tibial
Ankle plantar flexion Gastrocnemius/soleus + S1, 2 ++ Tibial
Great toe extension Extensor hallucis longus L5 Deep fibular
*The muscles listed in the ‘Upper motor neurone’ column are those that are preferentially affected in upper motor neurone lesions. The root level is the principal supply to a muscle.
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Surface anatomy
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A B
Gluteus medius
Gluteus minimus
Iliacus
Superior gluteal nerve
Tensor fasciae latae
Femoral nerve Piriformis
Obturator nerve
Pectineus Inferior gluteal nerve
Cutaneous branch Sciatic nerve
Lateral femoral Gluteus maximus
Obturator externus cutaneous nerve
Posterior femoral Semitendinosus
Adductor brevis cutaneous nerve
Medial femoral Biceps femoris,
cutaneous nerve long head
Sartorius Semimembranosus
Adductor longus Biceps femoris,
Rectus femoris short head Adductor magnus
Vastus lateralis
Gracilis Quadriceps
Vastus intermedius femoris
Vastus medialis
Adductor magnus
Intermediate femoral
Tibial nerve
cutaneous nerve
Common fibular nerve
Gastrocnemius, medial head
Common fibular nerve Popliteus
Deep fibular nerve Superficial fibular nerve Gastrocnemius, lateral head Soleus
Tibialis anterior Fibularis longus Plantaris
Extensor digitorum longus Tibialis posterior
Fibularis brevis
Flexor hallucis longus
Flexor digitorum longus
Extensor hallucis longus
Tibial nerve
Lateral sural
Saphenous nerve cutaneous nerve Sural nerve
Fibularis tertius
Calcaneal branch
Lateral plantar nerve to:
Extensor digitorum brevis
Abductor digiti minimi Medial plantar nerve to:
Flexor accessorius Abductor hallucis
Flexor digiti minimi Flexor digitorum brevis
Adductor hallucis Flexor hallucis brevis
Lumbricals 2–4 First lumbrical
Interossei Cutaneous branches
Cutaneous branches
Fig . 78 .11 The nerves of the lower limb, with their cutaneous and muscular branches . A, Anterior aspect . B, Posterior aspect . Adductor magnus has
dual innervation .
have been obtained by electrically stimulating spinal nerves and record- as the tip of the handle of a percussion hammer. Normally, this action
ing the evoked electromyographic activity in the muscles. Much of the elicits flexion of the toes. However, in patients with upper motor


information in Tables 78.1–78.4 is based on the clinical appreciation neurone lesions, the response includes extension of the great toe
of deficits following lesions to various nerves. (Babinski’s sign).
Reflexes Neurological localization of a lesion
Knee reflex (L2–4) With the patient sitting and the knee supported
Available with the Gray’s Anatomy e-book
and partially flexed, the patellar ligament is struck with a finger or
percussion hammer, resulting in extension of the knee joint.
SURFACE ANATOMY
Ankle reflex (S1, 2) With the patient sitting and the lower limb later-
ally rotated and partially flexed at the hip and knee, the foot is dorsi-
SKELETAL LANDMARKS
flexed by the examiner and the calcaneal tendon struck with a percussion
hammer. This results in plantar flexion of the foot.
Pelvis
Plantar reflex The plantar reflex is an important part of the clinical
examination of the central nervous system. With the foot relaxed, the The inguinal or groin skin crease marks the junction of the anterior
outer edge of the sole is stroked longitudinally with a blunt object such thigh with the anterior abdominal wall. It lies distal to the inguinal


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Pelvic girdle and lower limb: overview and surface anatomy
In clinical practice, it is only necessary to test a relatively small number
of muscles in order to determine the location of a lesion. Any muscle
to be tested must satisfy a number of criteria. It should be visible, so
that wasting or fasciculation can be observed, and the muscle consist-
ency with contraction can be felt. It should have an isolated action, so
that its function can be tested separately. It should help to differentiate
between lesions at different levels in the neural axis and in the periph-
eral nerve, or between peripheral nerves. It should be tested in such a
way that normal can be differentiated from abnormal, so that slight
weakness can be detected early with reliability. Some preference should
be given to muscles with an easily elicited reflex. Table 78.4 gives a list
of movements and muscles chosen according to these criteria; in prac-
tice, these tests would be combined with tests of sensory function.
Knowledge of the sequence in which motor branches leave a peripheral
nerve to innervate specific muscles is very helpful in localizing the level
of a lesion.
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A B
Iliohypogastric, L1
Subcostal, T12
Subcostal, T12
Femoral branch of
genitofemoral, L1, 2 Dorsal rami, L1, 2, 3
Dorsal rami, S1, 2, 3
Ilioinguinal, L1 C
Lateral femoral
cutaneous, L2, 3 Medial plantar
Lateral plantar
Obturator, L2, 3, 4
Lateral femoral
Medial and intermediate cutaneous, L2, 3 Saphenous
femoral cutaneous, L2, 3
Obturator, L2, 3, 4
Sural
Medial cutaneous
of thigh, L2, 3 Tibial
Posterior cutaneous
of thigh, S1, 2, 3
D
Lateral sural cutaneous,
Lateral sural cutaneous,
L4, 5, S1
L5, S1, 2
Deep fibular
Saphenous, L3, 4
Saphenous, L3, 4 Sural
Saphenous
Superficial fibular,
L4, 5, S1 Superficial fibular,
L5, S1 Superficial fibular
Sural, S1, 2 Sural, L5, S1, 2
Deep fibular, L5
Medial calcaneal
branches of tibial, S1, 2
Fig . 78 .12 The cutaneous nerves of the lower limb: areas of distribution and spinal segments of origin . A, Anterior aspect . B, Posterior aspect . C, The
sole of the foot . D, The dorsum of the foot .
Posterior Anterior Fig . 78 .14 Dermatomes
of the lower limb . There
T12
is considerable variation
T10
L1 and overlap between
L3 L3
L2 T11 dermatomes, but the
overlap across axial lines
T12 (heavy black) is minimal .
S3 S4 S5 L1 (With permission from


S2 S2 S3 O’Brien M, Aids to the
Examination of the
S4 Peripheral Nervous
S4 L2 System, 5th Edition,
May 2010, Elsevier,
L2 Saunders .)
S3 S3 S2
L3
S5
L2 L2 L3
L2 L2
S2
Fig . 78 .13 Dermatomes of the perineum . (With permission from O’Brien L4
M, Aids to the Examination of the Peripheral Nervous System, 5th Edition, L5
May 2010, Elsevier, Saunders .) L5 L4
S1
L5 S1
S1
L5
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Surface anatomy
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1
2
1
2
4 5
3
3
4 5 6
x x
xx 7
8 6 8
9 7
10 11
10
9
12 x
11
12
Fig . 78 .15 The inguinal region and femoral triangle . Key: 1, anterior
superior iliac spine; 2, lateral femoral cutaneous nerve and its zone of
emergence into femoral triangle (white): range 0 .3–7 .3 cm (mean
2 .1–3 .5 cm) from anterior superior iliac spine; 3, inguinal ligament;
4, femoral artery and zone of emergence into femoral triangle (white):
mid-inguinal point ± 1 cm either side, femoral nerve (yellow cross) and
vein (blue cross) sit lateral and medial, respectively, to the femoral artery;
5, femoral head: located 2–4 cm above the midpoint of the greater Fig . 78 .16 The gluteal region and sciatic nerve . Key: 1, zone of
trochanter to pubic tubercle line; 6, pubic tubercle; 7, greater trochanter supracristal plane intersection with vertebrae (white): ranges from the
to pubic tubercle line; 8, profunda femoris artery: almost always arises L2–L3 to the L4–L5 junction/interspinous space; 2, highest point of iliac
6 .5 ± 1 .5 cm distal to the mid-inguinal point, or superior crests (supracristal plane or Tuffier’s line): most commonly intersects the
to or at the level of the inguinal/groin crease; 9, zone of saphenofemoral L4 vertebra to the L4/5 junction; 3, zone of intersection between the
junction location: almost always sits within a 3 cm × 3 cm zone situated vertebrae and a horizontal plane between the posterior superior iliac
1–4 cm lateral and 0–3 cm inferior to the pubic tubercle; 10, sartorius; spines (white): ranges from the L5–S1 junction/interspinous space to S2


11, inguinal/groin crease; 12, adductor longus . (Adapted from Drake R, when determined via palpation, located at S2 via radiographs; 4, posterior
Vogl AW, Mitchell AW, et al, Gray’s Atlas of Anatomy, Elsevier 2008, superior iliac spine and interspinous plane: marked by a skin indentation
Churchill Livingstone .) (dimple of Venus); 5, safe zone (white) for gluteal region injection (upper
lateral quadrant), determined via a vertical line from the highest point of
the iliac crest to ischial tuberosity level, and a horizontal line passing
through its midpoint; 6, zone of termination of dural sac (blue): ranges
ligament by a mean of 6.7 ± 1.9 cm (Lechner et al 1988) (Fig. 78.15). from L5–S1 to S4, most commonly sitting from the lower part of S1 to the
The inguinal crease sits more distal to the inguinal ligament in females S2 level; 7, sacral hiatus bordered by sacral cornua, located at the apex
than in males (7.5 ± 1.9 cm versus 6.3 ± 1.9 cm) (Lechner et al 1988). of an approximately equilateral triangle with baseline measurement taken
The anterior superior iliac spine lies superior to the lateral end of the between the posterior superior iliac spines; 8, course of sciatic nerve:
fold, and from this point, the iliac crest is palpable along its entire from approximately one third of the way down a line joining the posterior
length. A line (Tuffier’s) joining the most superior aspects of the iliac superior iliac spine to the ischial tuberosity (black X and white zone) to
crests almost always crosses the L4 body or L4/L5 intervertebral disc the midpoint or middle third of a line joining the ischial tuberosity to the
(Render 1996, Walsh et al 2006, Chakraverty et al 2007) (Fig. 78.16). upper greater trochanter (blue X and white zone); 9, tip of coccyx within


This line is used as a landmark when performing a lumbar puncture; intergluteal cleft; 10, greater trochanter; 11, ischial tuberosity; 12, gluteal
localization via palpation, especially in females and patients with a fold . (Adapted from Drake R, Vogl AW, Mitchell AW, et al, Gray’s Atlas of
greater body mass index (BMI), often places it at a higher vertebral Anatomy, Elsevier 2008, Churchill Livingstone .)
level, up to the L2–L3 interspace (Chakraverty et al 2007, Kim et al
2007, Hale et al 2010). Vertebral column flexion in the adult has little
whose base is measured between the posterior superior iliac spines
effect on the level of Tuffier’s line (Kim et al 2003). In neonates, Tuffi-
(Senoglu et al 2005), although this arrangement may not always be
er’s line sits at the L4/L5 interlaminar space level whilst prone, moving
observed (Aggarwal et al 2009). The termination of the dural sac is
to the upper third of L5 during vertebral column flexion (van Schoor
et al 2014). The iliac crest terminates posteriorly as the posterior supe- located a mean of 31.6 ± 11.8 mm from the sacral hiatus apex (Aggar-
wal et al 2009), a point relevant to caudal anaesthetic administration.
rior iliac spine, which is marked superficially by the gluteal dimples
(dimples of Venus). Palpation places the posterior superior iliac spines
Femur
in the range of the L5–S1 vertebral junction to the S2 spinous process
level (Kim et al 2007), whereas radiographic assessment shows their
inferior margin to mark vertebral level S2 almost always (McGaugh The greater trochanter of the femur sits on the upper lateral thigh,
et al 2007). The caudal limit of the dura mater ranges from the L5–S1 inferior to the midpoint of the iliac crest and approximately level with


junction to S4 (Hansasuta et al 1999, Binokay et al 2006, Senoglu a horizontal plane passing through the pubic tubercle (see Fig. 78.15).
et al 2013), with the majority sitting at the lower S1 to the S2 level It can be used to guide surgeons during anterolateral approaches to the
(Senoglu et al 2013) and the mean position being lower in males hip joint. A line (Nelaton’s/Roser–Nelaton’s) drawn from the anterior
versus females (Binokay et al 2006). The ischial tuberosity is covered superior iliac spine to the ischial tuberosity passes superior to or over
by gluteus maximus and is palpable during hip flexion. The coccyx is the greater trochanter. In a patient with hip dislocation or femoral neck
palpable in the superior part of the intergluteal cleft, the deep vertical fracture, the greater trochanter can be palpated superior to this line. The
groove between the buttocks extending to the S3–S4 bony sacral seg- femoral shaft is not directly palpable but runs inferomedially from a
ments. The sacral hiatus sits superior to the tip of the coccyx at a mean point 2–3 cm medial to the lateral aspect of the greater trochanter to
of 57.5 ± 8.7 mm and is flanked by the raised palp able sacral cornua, the midpoint of the patella. The femoral head sits 2–4 cm superior to
which serve as reliable landmarks (Aggarwal et al 2009). The hiatus the midpoint of a line between the superior margin of the greater tro-
can also be located at the apex of an inverted equilateral triangle chanter and the pubic tubercle.


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NOITCES
When the knee is flexed, the medial surface of the medial condyle line and the edges of the patellar ligament. The iliotibial tract is attached
and the lateral surface of the lateral condyle of the femur may both be to a prominence, Gerdy’s tubercle, on the anterior aspect of the lateral
palpated, and portions of the femoral condylar articular surface can be condyle that is usually approximately 1 cm inferior to the joint line and
examined on each side of the patellar ligament. about 2 cm superolateral to the tibial tuberosity.
The head of the fibula forms a slight surface elevation on the poste-
Patella rior part of the proximal lateral leg. It lies vertically below the posterior
part of the lateral condyle of the femur, 1–2 cm inferior to the knee
joint line.
The entire patella is palpable except for its articular surface. When the
quadriceps femoris is relaxed in the fully extended knee, the patella
can be tilted and moved on the distal aspect of the femur. The inferior Leg and ankle
limit of the patella is located superior to the knee joint line by 1–2 cm
(Fig. 78.17).
The subcutaneous medial surface of the tibia corresponds to the flat
anteromedial aspect of the leg. Superiorly, this surface merges with the
Knee
medial condyle of the tibia, and inferiorly, it is continuous with the
visible prominence of the medial malleolus of the tibia (see Fig. 78.17;
The patella and the femoral condyles have been described above. The Figs 78.18–78.19). The anterior border of the tibia can be palpated
tibial condyles form visible and palpable landmarks on the medial and distinctly throughout most of its extent, but inferiorly, it is somewhat
lateral sides of the patellar ligament (see Fig. 78.17). The latter may be masked by the tendon of tibialis anterior, which lies to its lateral side.


traced inferiorly from the apex of the patella to the tibial tuberosity, The lateral malleolus of the fibula forms a conspicuous projection on
which is both visible and palpable. When the knee is flexed, the anterior the lateral side of the ankle; it descends to a more distal level than the
margins of the tibial condyles can be felt: each forms the lower bound- medial malleolus and is located on a more posterior plane. The lateral
ary of a depression at the side of the patellar ligament. The lateral aspect of the lateral malleolus is continuous superiorly with an elon-
condyle is the more prominent of the two. The joint line of the knee gated, subcutaneous, triangular area of the inferior shaft of the fibula.
(tibiofemoral joint) corresponds to the upper margins of the tibial The lateral part of the anterior margin of the inferior end of the tibia
condyles and can be represented by a line drawn round the limb at this can be palpated immediately anterior to the base of the lateral malleo-
level. The anterior horns of the menisci lie in the angles between this lus; the line of the ankle joint can be gauged from it.
Fig . 78 .17 The anterior aspect of the
knee and leg . Key: 1, vastus lateralis; Fig . 78 .18 The posterior aspect of the
2, vastus medialis; 3, iliotibial tract; knee and leg . Key: 1, popliteal artery:
4, quadriceps tendon overlying passing from a point (black X) 2 .5 cm
suprapatellar bursa; 5, sartorius; 6, x medial to the posterior midline of the
1 anterior horns of menisci: located above 1 thigh at the junction of its middle and
knee joint line (dotted line) and either lower thirds to a point halfway
2 side of patellar ligament; 7, Gerdy’s between the femoral condyles/the
3 4 tubercle; 8, fibular head; 9, patellar midaxial line of the calf (blue X); 2,
ligament insertion into tibial tuberosity; iliotibial tract; 3, tendon of biceps
10, anterior tibial artery and deep fibular 2 femoris and common fibular nerve


nerve: pass from halfway between fibular located medially; 4, semimembranosus
5 head and tibial tuberosity to a point and semitendinosus; 5, gracilis; 6,
6 6 halfway between the malleoli; 11, soleus 4 3 popliteal fossa; 7, head of fibula; 8,
and long saphenous vein (blue); 12, 5 gastrocnemius, lateral head; 9,
7 medial tibial border (subcutaneous); 13, gastrocnemius, medial head; 10,
8 medial malleolus: long saphenous vein soleus; 11, posterior tibial artery and
9 and saphenous nerve pass anterior; 14, 6 tibial nerve: run from the midaxial line
lateral malleolus; 15, tendon of tibialis of the calf at the fibular neck level to a
10 anterior . (Adapted from Drake R, Vogl point one-third of the way from the
AW, Mitchell AW, et al, Gray’s Atlas of x posterior border of the medial
Anatomy, Elsevier 2008, Churchill 7 malleolus to the calcaneal tendon; 12,
Livingstone .) medial malleolus; 13, lateral malleolus
and short saphenous vein passing
11 posteriorly; 14, calcaneal tendon
insertion into calcaneus . (Adapted
12 from Drake R, Vogl AW, Mitchell AW,
et al, Gray’s Atlas of Anatomy,
8 Elsevier 2008, Churchill Livingstone .)
9
10
11
13
15
14
12
14 13


Surface anatomy
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1
1
2
3 1
2
5 4 3
6 4 5 6
8 7
7 8
9
9
10
10
Fig . 78 .20 The medial aspect of the foot and ankle . Key: 1, long
11 saphenous vein and saphenous nerve; 2, medial malleolus; 3, posterior
tibial artery and tibial nerve: located approximately one-third of the
distance along a line passing from the posterior border of the medial
malleolus to the calcaneal tendon; 4, tendon of tibialis anterior: insertion
into medial cuneiform; 5, navicular tuberosity and tibialis posterior
insertion; 6, sustentaculum tali; 7, dorsal venous arch; 8, region of the
posterior tibial artery bifurcation into medial and lateral plantar arteries;
9, medial border of plantar aponeurosis; 10, medial calcaneal tubercle
covered by fibro-fatty heel pad . (Adapted from Drake R, Vogl AW, Mitchell
AW, Gray’s Anatomy for Students, 2nd ed, Elsevier 2010, Churchill
Livingstone .)
Fig . 78 .19 The dorsal aspect of the foot and ankle . Key: 1, long
saphenous vein and saphenous nerve; 2, medial malleolus; 3, lateral
malleolus; 4, dorsalis pedis artery and deep fibular nerve: located
1
immediately lateral to the tendon of extensor hallucis longus;
5, intermediate dorsal cutaneous nerve: visible passing towards the fourth
digit during digit and ankle plantar flexion; 6, extensor digitorum brevis; 2
7, tendon of extensor hallucis longus; 8, tendon of tibialis anterior:
3
insertion into medial cuneiform; 9, tuberosity of fifth metatarsal; 10, dorsal 3
4
venous arch of foot; 11, tendon of extensor digitorum longus (to digit
two) . (Adapted from Drake R, Vogl AW, Mitchell AW, Gray’s Anatomy for


Students, 2nd ed, Elsevier 2010, Churchill Livingstone .) 5
6
Foot 7
8
The anterior part of the upper surface of the calcaneus can be identified
slightly anterior to the lateral malleolus on the dorsum of the foot.
When the foot is passively inverted, the upper and lateral parts of the
head of the talus can be both seen and palpated approximately 3 cm
anterior to the distal end of the tibia; the extensor tendons obscure
them when the toes are extended. Regional tenderness can indicate a
talar neck fracture.
The dorsal aspects of the bodies of the metatarsals can be felt more
or less distinctly, although they are partly obscured by the extensor Fig . 78 .21 The anterolateral aspect of the foot and ankle . Key: 1, tendons
of fibularis longus and brevis; 2, tendons of extensor digitorum longus
tendons of the toes. The tuberosity on the base of the fifth metatarsal
and fibularis tertius; 3, inferior extensor retinaculum; 4, lateral malleolus;
forms a distinct palpable and visible projection on the lateral border of
5, fibular tubercle/trochlea; 6, tendon of fibularis tertius; 7,
the foot.
calcaneocuboid joint and transverse tarsal joint line; 8, tuberosity of fifth
The flat lateral surface of the calcaneus can be palpated on the lateral
metatarsal and tarsometatarsal (Lisfranc) joint line (dotted) . (Adapted from
aspect of the heel and can be traced anteriorly and inferior to the lateral
Drake R, Vogl AW, Mitchell AW, Gray’s Anatomy for Students, 2nd ed,
malleolus, where the tendons of fibularis longus and brevis hide it. The
Elsevier 2010, Churchill Livingstone .)
fibular (peroneal) tubercle, when sufficiently large, can be palpated
2 cm inferior to the tip of the lateral malleolus. A palpable depression
just anterior to the lateral malleolus leads to the lateral end of the tarsal


sinus. tubercles of the calcaneus can be palpated on its inferior surface via the
On the medial side of the foot, the sustentaculum tali can be felt anterior region of the fibro-fatty heel pad, which covers and obscures
approximately 2 cm inferior to the medial malleolus, with the tendon them. The heads of the metatarsals are similarly covered by a fibro-fatty
of flexor hallucis longus located inferiorly (Fig. 78.20). The navicular pad on the plantar surface of the foot and can be palpated on the dorsal
tuberosity is palpable and usually visible approximately 2.5 cm anterior foot, with the digits in flexion.
to the sustentaculum tali. Anterior to this, the medial cuneiform can be The calcaneocuboid joint is about 2 cm posterior to the tuberosity
identified, with the tendon of tibialis anterior inserting on to it. The on the base of the fifth metatarsal and is almost in line with the talo-
upper and medial parts of the joint between the medial cuneiform and navicular joint, whose position may be gauged from the talar head
the first metatarsal can be felt as a narrow groove. (Fig. 78.21). The tarsometatarsal (Lisfranc) joints lie on a line joining
When the foot is placed on the ground, it rests on the posterior part the tuberosity of the fifth metatarsal to the tarsometatarsal joint of the
of the inferior surface of the calcaneus, the heads of the metatarsals and, great toe, which is located 2–3 cm anterior to the navicular tuberosity
to a lesser extent, on its lateral border. The medial longitudinal arch of and is palpable. The joint between the second metatarsal and the inter-
the foot, the instep, is elevated from the ground. The medial and lateral mediate cuneiform is located 2–3 mm posterior to the line of the other


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NOITCES
tarsometatarsal joints. The metatarsophalangeal joints lie about 2.5 cm tubercle and produces the flattened appearance of the lateral thigh. It
behind the web spaces of the toes and are palpable on the dorsal foot, forms a defined ridge that is visible on the lateral aspect of the knee
where they are accessible via needle. either when the knee is extended against gravity or when the opposite
limb is lifted from the floor while standing.
The muscles of the posterior thigh may be palpated from the ischial
MUSCULOTENDINOUS AND tuberosity inferiorly along the lateral (biceps femoris) and medial
LIGAMENTOUS LANDMARKS (semitendinosus and semimembranosus) aspects of the thigh.
See Video 78.1. Knee
Buttock and hip
The large depression visible posterior to the knee when the joint is
actively flexed against resistance corresponds to the popliteal fossa. The
The bulky prominence of the buttock is formed by gluteus maximus, a transverse skin crease of the popliteal fossa is located 2–3 cm superior
variable amount of subcutaneous fat and the normal alignment of the to the knee joint line. The fossa is bounded on the superolateral side
pelvis, which angles the ischium posteriorly (see Fig. 78.16). by the prominent tendon of biceps femoris, which can be palpated
The horizontal gluteal fold marks the upper limit of the posterior between the finger and thumb and traced inferiorly to the head of the
aspect of the thigh. It does not correspond to the lower border of gluteus fibula. Three tendons, of semitendinosus, gracilis and semimembrano-
maximus but is formed by fibrous connections between the skin and sus, can be felt on the superomedial side of the fossa. Semitendinosus
the deep fascia. The intergluteal cleft, which separates the buttocks is the most lateral and posterior, while gracilis is the most medial and


inferiorly, begins superiorly at the S3 or S4 vertebrae. The superior anterior; both tendons stand out sharply and can be seen when the knee
border of gluteus maximus begins on the iliac crest 5–7 cm superola- is flexed against resistance and the limb actively adducted. The tendon
teral to the posterior superior iliac spine and runs inferiorly and later- of semimembranosus may be palpated deeply in the interval between
ally towards the apex of the greater trochanter. Its lower border the tendons of semitendinosus and gracilis. It is much thicker than the
corresponds to a line drawn from the ischial tuberosity, through the other two tendons and broadens rapidly as it is traced proximally. The
midpoint of the gluteal fold, to a point approximately 9 cm below the upper borders of the two heads of gastrocnemius form the inferomedial
greater trochanter. Although gluteus maximus overlaps the ischial tuber- and inferolateral boundaries of the popliteal fossa.
osity in the standing position, on sitting, it slides superiorly posterior The cord-like fibular collateral ligament may be felt passing from the
to the tuberosity, leaving it free to bear weight. Gluteus maximus can apex of the fibular head to the lateral epicondyle of the femur when
be felt to contract when the hip is extended against resistance. the knee is flexed and laterally directed pressure (valgus force) is applied
Gluteus medius completely covers the underlying gluteus minimus. to the medial side of the knee. The medial patellar retinaculum may be
Both muscles lie in a slight depression superolateral to gluteus maximus felt as a flat, broad band overlying the medial femoral condyle in the
and inferior to the anterior portion of the iliac crest and both pass flexed knee, running between the midpoint of the medial side of the
inferiorly to insert into the greater trochanter. They constitute the major patella and the medial femoral epicondyle.
abductors of the hip and are demonstrated by asking the subject to
stand on one limb. The ipsilateral muscles contract to stabilize the
Leg
centre of gravity and maintain a relatively horizontal pelvic position.


Paresis or paralysis causes pelvic tilt towards the unsupported, contra-
lateral side (Trendelenburg’s sign). The muscles in the anterior osteofascial compartment of the leg form
a gentle prominence over the upper two-thirds of its anterolateral
Thigh aspect; this prominence is accentuated when the foot is actively dorsi-
flexed. These muscles are replaced by their tendons in the lower third
of the leg. The tendon of tibialis anterior can be seen just lateral to the
The inguinal ligament can be felt running between the anterior superior
anterior border of the tibia and traced inferiorly and medially across
iliac spine and the pubic tubercle, especially when the thigh is abducted
the anterior aspect of the ankle to the medial cuneiform (see Figs 78.17,
and laterally rotated (see Fig. 78.15). The groin/inguinal crease (Hold-
78.19). The other tendons cannot be examined satisfactorily superior
en’s line), where the deep layer of the subcutaneous tissue of the ant-
to the ankle. Immediately superior to the posterior border of the medial
erior abdominal wall meets the fascia lata of the thigh, is distal to the
malleolus and close to the medial border of the tibia, the tendons of
inguinal ligament and runs obliquely. It lies a mean of 6.7 ± 1.9 cm
tibialis posterior and flexor digitorum longus can be felt (rather indis-
distal to the inguinal ligament (Lechner et al 1988).
tinctly) when the foot is actively inverted and plantar flexed.
The femoral triangle is located on the proximal anterior thigh. It is
On the lateral aspect of the leg, fibularis longus can be seen as a
bounded superiorly by the inguinal ligament and laterally by the strap-
narrow ridge following the line of the lateral aspect of the fibula during
like sartorius, which can be both seen and felt in a reasonably thin and
active eversion and plantar flexion of the foot. It covers and hides fibu-
muscular subject when the hip is flexed in the sitting position, while
laris brevis. The shaft of the fibula can only be palpated indistinctly
the knee is kept extended and the thigh is slightly abducted and rotated


between its neck and the area above the lateral malleolus.
laterally. Sartorius can be traced inferomedially from the anterior supe-
The bulky prominence of the posterior leg is formed by gastro-
rior iliac spine to approximately halfway down the medial side of the
cnemius and soleus, both of which can be identified either when the
thigh; distally, it may be identified as a soft longitudinal ridge passing
foot is plantar flexed against resistance, or when the heel is raised from
towards the posterior part of the medial femoral condyle. The adductor
the ground by standing on tiptoes (see Fig. 78.18). The two heads of
group of muscles forms the bulky, fleshy mass at the upper part of the
gastrocnemius unite to form the inferior borders of the popliteal fossa.
medial thigh. The medial boundary of adductor longus forms the
The medial head of gastrocnemius descends to a more inferior level
medial boundary of the femoral triangle and can be felt as a distinct
than the lateral head. Soleus lies deep to gastrocnemius; when tensed,
ridge when the thigh is adducted against resistance. At its superior end,
it bulges from under the medial and lateral margins of gastrocnemius,
its prominent tendon of origin can be seen and palpated immediately
particularly on the lateral side, and its fleshy belly extends to a more
inferior to the pubic tubercle, which is a useful guide to this bony
distal level. Both muscles end inferiorly in the conspicuous calcaneal
landmark.
tendon, which can be palpated between the finger and thumb and fol-
The forward convexity of the anterior thigh is caused by the curvature
lowed inferiorly to its insertion into the posterior aspect of the
of the femur covered by the muscle mass of quadriceps femoris. Rectus
calcaneus.
femoris appears as a raised ridge passing down the anterior aspect of
the thigh to the patellar base, when the sitting subject flexes the hip
Foot
with the knee extended. Vastus medialis constitutes a bulge that is both
superior and medial to the patella (see Fig. 78.17). Vastus lateralis forms


an elevation superior and lateral to the patella that is more proximal When the toes are actively extended, the bellies of extensor digitorum
and less pronounced than that of vastus medialis. Vastus intermedius brevis and extensor hallucis brevis form a small elevation on the dorsal
is covered by the three other muscles in the group. The thick tendon of foot, just anterior to the lateral malleolus (see Fig. 78.19). During ankle
adductor magnus can be palpated on the distal medial thigh, deep inversion and extension of the toes, the prominent tendon of tibialis
within the indentation formed between vastus medialis anteriorly and anterior is visible on the medial side of the dorsal foot, passing inferi-
gracilis and sartorius posteriorly. orly and medially to the medial cuneiform. The tendon of extensor
The iliotibial tract, a thickened portion of the deep fascia of the thigh hallucis longus can be identified laterally; the tendons of extensor digi-
(fascia lata), runs from the lateral aspect of the iliac crest to Gerdy’s torum longus and fibularis tertius are further lateral as they pass deep


Surface anatomy
1331
87
RETPAHC
to the inferior extensor retinaculum and immediately anterior to the significant cardiac output in cases of circulatory collapse. It is a common
lateral part of the distal tibia. More distally, the tendons of extensor site for catheter insertion for radiological examinations such as cardiac
digitorum longus and fibularis tertius diverge and may be traced to their angiography and for arterial puncture for blood gas analysis.
insertions.
The tendon of tibialis posterior winds posterior to the medial malle- Popliteal artery The pulse of the popliteal artery is the most diffi-
olus and then curves anteriorly in the interval between this bony land- cult of the peripheral pulses to feel because the artery lies deep in the
mark and the sustentaculum tali to reach the tuberosity of the navicular popliteal fossa. It is best examined with the subject lying supine or
(see Fig. 78.20). The tendon is visible and palpable posterior to the prone, with the knee flexed in order to relax the tense popliteal fascia
malleolus when the foot is forcibly plantar flexed and inverted. The that roofs the popliteal fossa. The popliteal pulse is then felt over the
tendon of flexor digitorum longus lies immediately posterolateral to midline of the fossa by deep pressure against the popliteal surface of
that of tibialis posterior. It curves forwards inferior to tibialis posterior the femur.
and lies on the medial aspect of the sustentaculum tali. From there, it
passes anteriorly and laterally to the centre of the plantar foot, where Posterior tibial artery The pulse of the posterior tibial artery can
it divides into four tendons that pass to the lateral four toes. The tendon be felt by gentle palpation posterior to the medial malleolus as the
of flexor hallucis longus lies inferior to, and grooves, the sustentaculum artery lies between the tendons of flexor hallucis longus and flexor digi-
tali. As it passes towards the great toe, it crosses the line of the flexor torum longus, approximately one-third of the way along a line connect-
digitorum longus opposite the interval between the sustentaculum ing the posterior border of the medial malleolus to the calcaneal


tali and the tuberosity of the navicular. Abductor hallucis may be seen tendon.
in some subjects as a fleshy mass along the medial border of the
foot, passing from the medial calcaneal tubercle to the first metatarso- Dorsalis pedis artery The dorsalis pedis arterial pulse is found by
phalangeal joint. palpation against the underlying tarsals, immediately lateral to the
When the toes are maximally dorsiflexed, the plantar aponeurosis is tendon of extensor hallucis longus, from the midpoint between the
easily palpated along the medial border of the foot, from just distal to malleoli to the proximal end of the first intermetatarsal space.
the heel pad as far as the first metatarsophalangeal joint. It originates
from the calcaneal tubercles, which may be palpable via the anterior Veins
aspect of the heel pad.
The femoral vein is located immediately medial to the femoral artery
VESSELS, PULSES AND NERVES pulse, where it can be accessed (see Fig. 78.15). While femoral vein
puncture is relatively easy and supplies ready access to the right atrium,
the use of this approach is relatively unpopular for long-term cannul-
Arteries
ation because of a greater incidence of thrombosis and sepsis. However,
it is a useful site for venous sampling in a patient with collapsed veins.
The femoral artery normally enters the anterior thigh at the mid- For femoral vein cannulation, the skin puncture site is approximately
inguinal point ± 1 cm either side (medial to lateral) (Hale et al 2010) 1 cm medial to the femoral artery and just inferior to the inguinal
(see Fig. 78.15). The midinguinal point is halfway between the anterior ligament.
superior iliac spine and the pubic symphysis. The artery normally passes The dorsal venous arch of the foot is visible and curves across the
directly anterior to the hip joint; its course may be represented by the metatarsals (see Fig. 78.19). The long saphenous vein arises from the
upper two-thirds of a line joining its entry point into the thigh with the medial end of the arch, and the short saphenous vein arises from


adductor tubercle, when the thigh is flexed, slightly abducted and the lateral end. The long saphenous vein can be seen and palpated
rotated laterally. It travels deep to sartorius from the apex of the femoral anterior to the medial malleolus, after which it runs superiorly and
triangle to the adductor hiatus. The profunda femoris artery (deep artery posteriorly across the distal medial surface of the tibia: this is a useful
of the thigh) normally arises from the lateral side of the femoral artery, site for surgical venous access (cut-down) or venous harvesting for
6.5 ± 1.5 cm distal to the mid-inguinal point (Choy et al 2013), which cardiac bypass surgery (see Figs 78.17, 78.19). The vein then runs proxi-
is most commonly at or superior to the level of the inguinal/groin mally along the posterior aspect of the medial border of the tibia, where
crease (Lechner et al 1988). it is accompanied by the saphenous nerve, to reach a point a hand’s
The popliteal artery may be represented by a line extending from the breadth (7–10 cm) posterior to the medial patellar border. From here,
junction of the middle and lower thirds of the thigh, 2.5 cm medial to the vein ascends the thigh to the saphenous opening, where it passes
its posterior midline, to a point halfway between the femoral condyles, deep to enter the femoral vein. An image-based study found that the
and continuing inferolaterally to the level of the tibial tuberosity, saphenofemoral junction almost always occupied a 3 × 3 cm zone
medial to the fibular neck, where it bifurcates into the anterior and located 1–4 cm lateral and 0–3 cm inferior to the pubic tubercle
posterior tibial arteries (see Fig. 78.18). (Mirjalili et al 2014) (see Fig. 78.15). The junction was nearer to the
The anterior tibial artery may be represented by a line extending pubic tubercle in younger and thinner subjects.


from a point halfway between the tibial tuberosity and the fibular head The course of the short saphenous vein may be represented by a line
to a point midway between the anterior borders of the two malleoli from the posterior surface of the lateral malleolus superiorly along the
(see Fig. 78.17). It passes on to the dorsal foot lateral to the tendon of midline of the calf to the popliteal fossa; together with the sural nerve,
extensor hallucis longus, as the dorsalis pedis artery. The latter gives off this vein is the key anatomical guide to surgical dissection of the pop-
a medial branch that travels toward the first intermetatarsal space. liteal fossa (see Fig. 78.18).
The posterior tibial artery may be represented by a line drawn from
a midaxial point on the calf (approximately midway between the
Nerves
tibial condyles) at the level of the neck of the fibula, to a point one-
third of the way between the posterior border of the medial malleolus
and the calcaneal tendon (see Fig. 78.18). The same line represents In the proximal femoral triangle, the femoral nerve is located immedi-
the course of the tibial nerve. At first, the nerve lies lateral to the pop- ately lateral to the femoral artery pulse.
liteal artery but gradually crosses the vessel to gain its medial side. The The surface marking for the course of the saphenous nerve in the
posterior tibial artery bifurcates into the plantar arteries halfway leg matches that of the long saphenous vein (see above). The lateral
between the medial malleolus and the medial calcaneal tubercle (see femoral cutan eous nerve enters the femoral triangle 2.1–3.5 cm (range
Fig. 78.20). 0.3–7.3 cm) from the anterior superior iliac spine (see Fig. 78.15)
The medial plantar artery passes anteriorly towards the great toe. (Grothaus et al 2005, Bjurlin et al 2007, Ropars et al 2009). It then passes
The lateral plantar artery passes obliquely towards a point approxi- over the lateral border of sartorius up to 11.3 cm distal to the anterior


mately 2.5 cm medial to the tuberosity of the fifth metatarsal, after superior iliac spine (Grothaus et al 2005, Ropars et al 2009), and over the
which it enters the proximal part of the fourth intermetatarsal space. anterior border of tensor fasciae latae between 2.4 and 9.2 cm distal to
Digital arteries and nerves pass along the medial and lateral sides of the anterior superior iliac spine (Ropars et al 2009). The nerve is at risk
the toes. of damage during anterolateral surgical approaches to the hip.
The course of the sciatic nerve can be represented by a curved line
Pulses
that starts at a point 0.3 ± 0.05 of the distance down a line drawn from
Femoral artery The pulsations of the femoral artery can be felt at its the posterior superior iliac spine to the ischial tuberosity, and passes to
entry point into the proximal femoral triangle, where it can be com- a point 0.5 ± 0.05 of the distance along a line drawn from the ischial
pressed against either the superior pubic ramus or the hip joint. The tuberosity to the greater trochanter (see Fig. 78.16). It then continues
pulse of the femoral artery is of value in assessing whether there is any vertically and inferiorly in the midline of the posterior aspect of the


PElvIC GIRdlE ANd lOwER lImb: OvERvIEw ANd SuRFACE ANATOmy
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9
NOITCES
thigh, deep to biceps femoris, to the upper angle of the popliteal fossa, Knee The lateral retropatellar approach is used. With the patient
where it divides into the tibial and common fibular nerves (if it has not supine and the knee extended, the needle is introduced at the level of
already done so at a more superior level). the superior border of the patella and guided towards the suprapatellar
The surface marking for the course of the tibial nerve in the leg bursa.
matches that of the posterior tibial artery (see above). The course of the
sural nerve at the ankle can be represented by a line running parallel Popliteal fossa Sciatic nerve blocks at the popliteal fossa in infants and
to the calcaneal tendon that is situated halfway between the tendon and children can be effectively performed above the popliteal skin crease by
the lateral malleolus: this position is variable and the sural nerve is at correcting the adult landmark of 10 cm by the ratio of the calculated
risk from surgery in this region. child femoral shaft length over the adult femoral shaft length (Bernière
The course of the common fibular nerve can be indicated by a line et al 2008).
that runs from the superior angle of the popliteal fossa, along the
medial side of the tendon of biceps femoris (see Fig. 78.18) and then Ankle The anterior approach entails introducing the needle between
curves inferiorly and anteriorly around the neck of the fibula approxi- the tendons of tibialis anterior and extensor hallucis longus with the
mately 3 cm distal to the superior tip of the fibula. The common fibular foot partially plantar flexed.
nerve is palpable medial and distal to the tendon of biceps femoris and
over the neck of the fibula, although here it becomes less distinct as it
Arthroscopy portals
passes deep to the origin of fibularis longus. At the neck of the fibula,
the nerve is at particular risk of damage either from a tightly applied
plaster cast or from a fracture. The placement of portals for arthroscopy is important for maximizing


The deep fibular nerve starts on the lateral aspect of the neck of the surgical access for visualization and for surgical instruments, and also
fibula, passes downwards and medially, and rapidly becomes associated for avoiding damage to structures such as nerves and blood vessels.
with the anterior tibial artery, with which it is landmarked (see Fig.
78.18). The superficial fibular nerve also begins on the lateral aspect of Hip Arthroscopy of the hip is not yet a common procedure but is
the neck of the fibula. It descends to a point on the anterior border of increasingly being used. A variety of entry portals have been described.
fibularis longus, at the junction of the middle and lower thirds of the The anterolateral portal is sited on the skin approximately 4 cm lateral
leg, where it pierces the deep fascia and divides into intermediate and to the femoral artery pulse and 4 cm inferior to the inguinal ligament.
medial dorsal cutaneous branches. The intermediate dorsal cutaneous Under fluoroscopy, a needle traversing the skin 30–45 degrees proxi-
branch is normally both visible and palpable over the dorsolateral mally is advanced into the joint. Other more lateral portals can be used;
aspect of the ankle and foot toward the fourth toe (see Fig. 78.19). The the lateral femoral cutaneous nerve and the sciatic nerve are potentially
medial dorsal cutaneous branch is rarely visible and passes towards the at risk.
second toe. These superficial nerves are at risk from surgery in the ant-
erior ankle region (especially during arthroscopy). Knee The knee is the joint most frequently examined with arthroscopy.
The standard portals are placed anteriorly. When the knee is flexed at a
right angle, ‘soft triangles’ bordered by the patellar ligament, the femoral
CLINICAL PROCEDURES condyles and the tibia and anterior horns of the menisci are palpable
on either side of the superior third of the patellar ligament. Small inci-
Nerve anaesthesia (nerve blocks) sions can be made in the apices of these triangular areas at about the
level of the inferior pole of the patella for the anterolateral portal, and
Nerves can be effectively anaesthetized with local anaesthetic injection slightly lower for the anteromedial portal. These portals will allow


for surgical or post-injury pain relief. Common injection sites for the passage of an arthroscope and instruments, with good access to most
lower limb are around the hip for thigh and knee pain, and around the of the joint. The patellar ligament and the infrapatellar branch of the
ankle for foot surgery. For the deeper nerves around the hip, the use of saphenous nerve are at risk from the skin incisions. The nerve is less
a nerve stimulator is very helpful in localizing the target nerve precisely vulnerable than the ligament; its position is variable but it usually lies
before infiltration of local anaesthetic. For example, blockade of the below the appropriate portal sites. In the days of open meniscal surgery,
sciatic nerve in the buttock, femoral nerve in the anterior thigh, and the nerve was usually divided and painful neuroma formation was not
obturator nerve in the medial thigh may be undertaken to provide pain uncommon.
relief for total knee replacement; the tibial nerve at the posteromedial Posteromedial and posterolateral portals are useful when better
ankle, the sural nerve at the posterolateral ankle and the superficial access to the posterior knee is required. The saphenous and common
fibular nerves at the anterior ankle may all be anaesthetized at the ankle fibular nerves, respectively, are at risk with these approaches, and ana-
to allow ‘awake foot surgery’. tomical knowledge is vital to ensure safe portal placement. Laterally,
the incision should be anterior to the tendon of biceps femoris, which
Intramuscular injection can easily be palpated. Medially, the situation is more difficult because
the saphenous nerve and long saphenous vein travel superficial to the
medial epicondylar region of the knee, approximately a hand’s breadth
Intramuscular injections into the buttock should be avoided to prevent
posterior to the medial border of the patella. It is essential that sharp
iatrogenic damage to the sciatic nerve. If the buttock is to be used, a
incision includes the skin only, and that dissection down to the joint
relatively safe area is the true upper and outer quadrant, which is iden-
capsule is undertaken bluntly. If the medial meniscus is sutured, the
tified with the whole buttock exposed. The injection is then given


capsule must be exposed before tying off sutures to avoid ensnaring the
mainly into gluteus medius rather than into gluteus maximus, pro-
nerve.
vided a sufficiently long needle is used; most so-called ‘intramuscular’
injections given into the buttock are actually given into the fat. A safe Ankle The use of ankle arthroscopy is well established, especially
alternative is to inject into the lateral aspect of the thigh (vastus
in treating sports-related injuries. Anterior portals are standard. The
lateralis).
anteromedial portal can be placed just medial to the tendon of tibialis
anterior, in the palpable soft spot. However, this comes close to the long
Joint injection and aspiration
saphenous vein and saphenous nerve; limiting the sharp incision to the
skin, followed by blunt deeper dissection, reduces the risk. Alternatively,
Careful aseptic technique is essential for all joint aspirations and the anteromedial portal can be chosen to pass between the lateral edge
injections. of tibialis anterior and extensor hallucis longus. The anterolateral portal
is placed with the help of the arthroscope in the joint to check the
Hip Intra-articular hip injections are typically performed under fluoro- position of a preliminary needle passed into it. The portal should pass
scopic or ultrasonographic guidance. With the patient lying supine, and lateral to fibularis tertius and extensor digitorum longus. The intermedi-
after the positions of the femoral artery and the anterior superior iliac ate dorsal cutaneous branch of the superficial fibular nerve is at risk
spine have been marked out, the needle is introduced anteriorly, as it crosses the ankle anterior to the lateral malleolus, and therefore
approximately 5 cm distal to the anterior superior iliac spine and 4 cm it is wise to mark the positions of the nerves and blood vessels with a
lateral to the femoral artery pulse, and passed posteriorly, a little proxi- pen before making any incision. The nerves can usually be felt at the
mally and medially. An alternative technique that is dependent on front of the ankle, even in obese patients. They are often seen if the
relative distances from surface landmarks, rather than imaging guid- ankle is maximally pulled into plantar flexion. Posterior ankle arthros-


ance, utilizes the site of the proximal anterolateral portal for hip copy is controversial: there is a view that the proximity of the neurov-
arthroscopy as the point of needle insertion (Masoud and Said 2013). ascular bundle (medially) and the sural nerve (laterally) renders it too


1333
87
RETPAHC
Key references
hazardous. Keeping lateral to the tendon of flexor hallucis longus will the saphenous nerve, means that there is always numbness lateral to a
safeguard the medial neurovascular bundle. longitudinal incision.
The extensile approach to the posterior knee is extensive. The key is
to expose the sural nerve and short saphenous vein and to trace them
Placement of surgical incisions
proximally. This will lead the surgeon into the popliteal fossa and, after
opening the deep fascia, safely to the neurovascular bundle. The wound
Hip Surgery of the hip joint is usually undertaken for congenital issues, crosses a flexure crease. A scar perpendicular to the crease might induce
slipped capital femoral epiphysis in children, trauma or arthroplasty. a fixed flexion contracture of the joint and therefore an S-shaped inci-
Anterior and anterolateral approaches, often used in children, put the sion is employed where the transverse segment runs in the line of the
lateral femoral cutaneous nerve at considerable risk. Even in more flexure crease.
lateral approaches, the lateral femoral cutaneous nerve and the femoral
and sciatic nerves are all at risk through traction. A popular anterolateral Ankle and foot Incisions around the foot and ankle frequently put
approach to the hip joint involves splitting and separating forwards the
cutaneous nerves at risk and such an injury can result in a neuroma.
anterior part of gluteus medius and vastus lateralis as a single sheet of
The sural nerve at the ankle has a notorious tendency to form neuromas
tissue for subsequent reattachment to the greater trochanter. This tech-
if transected, often after repair of a ruptured calcaneal tendon.
nique relies on the anatomical continuity of the tissue. If the splitting
of gluteus medius is more than a few centimetres superior to the tip of
the greater trochanter, then the superior gluteal nerve and vessels are at
Bonus e-book tables and video
risk, and weakness of hip abduction and a limp may result. In the
posterior approach to the hip joint, gluteus maximus is incised in
the line of its fibres. This is followed by division of the tendons of


Table 78 .1 Segmental innervation of the muscles of the lower limb .
the short lateral rotators (piriformis, obturator internus and externus
and gemelli) near their trochanteric attachments to reveal the joint
Table 78 .2 Segmental innervation of joint movements of the lower
capsule. Reflecting these cut tendons medially protects the sciatic nerve.
limb .
The inferior and superior gluteal nerves are at risk during posterior
approaches to the hip.
Table 78 .3 Movements, muscles and segmental innervation in the
lower limb .
Knee Most open knee surgery can be undertaken through an anterior
midline longitudinal incision, which gives good access and means that Table 78 .4 The movements and muscles tested to determine the
any future surgery can usually be undertaken via the same wound. New location of a lesion in the lower limb .
incisions run the risk of skin necrosis and poor wound healing as a
consequence of interfering with the cutaneous blood supply. Inevitable Video 78 .1 Lower limb surface anatomy .
interruption of cutaneous nerves, including the infrapatellar branch of
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Pelvic girdle and lower limb: overview and surface anatomy
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1333.e1


CHAPTER Development of the pelvic girdle and
79
lower limb
By stage 17, the lower limb still has a flattened foot plate and,
PELVIC GIRDLE DEVELOPMENT
although a hip region can be identified, there is no true knee as yet. In
stage 18, the lower limb appears to be flexed and abducted at the
The pelvic girdle develops in close proximity to cloacal structures. The hip with the knee bent, giving the appearance that the knee is facing
anterior portion of the pelvic girdle is intimately associated with the laterally. The femur and tibia form in cartilage, and the sciatic nerve
normal development of the caudal part of the urogenital system and extends distally to the tibia by stage 18. Very little skin of the thigh is
the anterior body wall. Studies on the development of the lower limb visible. The soles of the feet face the umbilical cord, and the foot plate
in avian species and the mouse show that the perineal muscles, includ- has digit rays. During stages 20–23, the digit rays separate and toes are
ing the sphincters, derive from somitic myoblasts that have previously clearly defined by stage 23. The feet can finally touch at stage 21, when
entered the hindlimb bud. Similar to the developmental process seen the umbilical cord becomes proportionally smaller and the embryo
in the upper limb, somitic myoblasts originating from the dorsoventral larger. For more details, see O’Rahilly and Gardner (1975).
edge of the dermomyotome migrate into the somatopleuric mesen-
chyme of the early lower limb bud. The myoblasts coalesce into a single
entity before dividing into dorsal and ventral muscle masses. The cells VESSELS
of the ventral muscle mass then divide again, with one population
continuing to develop within the limb and the other migrating ventrally Arteries
towards the genital tubercle (Valasek et al 2005). In the avian embryo,
myoblasts from somites 26–29 enter the limb only, and those from
The blood supply to the lower limb is derived from the lateral branch
somites 30–33 form both cloacal and limb muscles, whereas those from
of the fifth lumbar intersegmental artery, which arises from the dorsal