hip fracture hip fracture a hip fracture is a break that occurs in the upper part of the femur (thigh bone), at the femoral neck or (rarely) the femoral head. symptoms may include pain around the hip, particularly with movement, and shortening of the leg. usually the person cannot walk. this article is about fractures of the proximal femur. for fractures of the nonacetabular portion of the hip bone, see pelvic fracture. for fractures of the acetabulum, see acetabular fracture. not to be confused with femoral fracture. hip fractureother namesproximal femur fracture; femoral neck fracture ; femoral head fracture intertrochanteric hip fracture in a 17-year-old malesymptomspain around the hip particularly with movement, shortening of the legtypesintracapsular, extracapsular (intertrochanteric, subtrochanteric, greater trochanteric, lesser trochanteric)causestrauma such as a fallrisk factorsosteoporosis, taking many medications, alcohol use, metastatic cancerdiagnostic methodx-ray, mri, ct scan, bone scandifferential diagnosisosteoarthritis, avascular necrosis of the hip, hernia, trochanteric bursitispreventionimproved lighting, removal of loose rugs, exercise, treatment of osteoporosistreatmentsurgerymedicationopioids, nerve blockprognosis~20% one year risk of death (older people)frequency~15% of women at some point a hip fracture is usually a femoral neck fracture. such fractures most often occur as a result of a fall. (femoral head fractures are a rare kind of hip fracture that may also be the result of a fall but are more commonly caused by more violent incidents such as traffic accidents.) risk factors include osteoporosis, taking many medications, alcohol use, and metastatic cancer. diagnosis is generally by x-rays. magnetic resonance imaging, a ct scan, or a bone scan may occasionally be required to make the diagnosis. pain management may involve opioids or a nerve block. if the person's health allows, surgery is generally recommended within two days. options for surgery may include a total hip replacement or stabilizing the fracture with screws. treatment to prevent blood clots following surgery is recommended. about 15% of women break their hip at some point in life; women are more often affected than men. hip fractures become more common with age. the risk of death in the year following a fracture is about 20% in older people. signs and symptoms the affected extremity is often shortened and unnaturally, externally rotated compared to the unaffected leg the classic clinical presentation of a hip fracture is an elderly patient who sustained a low-energy fall and now has groin pain and is unable to bear weight. pain may be referred to the supracondylar knee. on examination, the affected extremity is often shortened and externally rotated compared to the unaffected leg. complications nonunion, failure of the fracture to heal, is common in fractures of the neck of the femur, but much more rare with other types of hip fracture. avascular necrosis of the femoral head occurs frequently (20%) in intracapsular hip fractures, because the blood supply is interrupted. malunion, healing of the fracture in a distorted position, is very common. the thigh muscles tend to pull on the bone fragments, causing them to overlap and reunite incorrectly. shortening, varus deformity, valgus deformity, and rotational malunion all occur often because the fracture may be unstable and collapse before it heals. this may not be as much of a concern in patients with limited independence and mobility. hip fractures rarely result in neurological or vascular injury. medical many people are unwell before breaking a hip; it is common for the break to have been caused by a fall due to some illness, especially in the elderly. nevertheless, the stress of the injury, and a likely surgery, increases the risk of medical illness including heart attack, stroke, and chest infection. hip fracture patients are at considerable risk for thromboemoblism, blood clots that dislodge and travel in the bloodstream. deep venous thrombosis (dvt) is when the blood in the leg veins clots and causes pain and swelling. this is very common after hip fracture as the circulation is stagnant and the blood is hypercoagulable as a response to injury. dvt can occur without causing symptoms. a pulmonary embolism (pe) occurs when clotted blood from a dvt comes loose from the leg veins and passes up to the lungs. circulation to parts of the lungs is cut off which can be very dangerous. fatal pe may have an incidence of 2% after hip fracture and may contribute to illness and mortality in other cases. mental confusion is extremely common following a hip fracture. it usually clears completely, but the disorienting experience of pain, immobility, loss of independence, moving to a strange place, surgery, and drugs combine to cause delirium or accentuate pre-existing dementia. urinary tract infection (uti) can occur. patients are immobilized and in bed for many days; they are frequently catheterised, commonly causing infection. prolonged immobilization and difficulty moving make it hard to avoid pressure sores on the sacrum and heels of patients with hip fractures. whenever possible, early mobilization is advocated; otherwise, alternating pressure mattresses should be used. risk factors hip fracture following a fall is likely to be a pathological fracture. the most common causes of weakness in bone are: osteoporosis. other metabolic bone diseases such as paget's disease, osteomalacia, osteopetrosis and osteogenesis imperfecta. stress fractures may occur in the hip region with metabolic bone disease. elevated levels of homocysteine, a toxic 'natural' amino acid. benign or malignant primary bone tumors are rare causes of hip fractures. metastatic cancer deposits in the proximal femur may weaken the bone and cause a pathological hip fracture. infection in the bone is a rare cause of hip fracture. tobacco smoking (associated with osteoporosis). mechanism x-ray of a normal hip joint. functional anatomy the hip joint is a ball-and-socket joint. the femur connects at the acetabulum of the pelvis and projects laterally before angling medially and inferiorly to form the knee. although this joint has three degrees of freedom, it is still stable due to the interaction of ligaments and cartilage. the labrum lines the circumference of the acetabulum to provide stability and shock absorption. articular cartilage covers the concave area of acetabulum, providing more stability and shock absorption. surrounding the entire joint itself is a capsule secured by the tendon of the psoas muscle and three ligaments. the iliofemoral, or y, ligament is located anteriorly and serves to prevent hip hyperextension. the pubofemoral ligament is located anteriorly just underneath the iliofemoral ligament and serves primarily to resist abduction, extension, and some external rotation. finally the ischiofemoral ligament on the posterior side of the capsule resists extension, adduction, and internal rotation. when considering the biomechanics of hip fractures, it is important to examine the mechanical loads the hip experiences during low energy falls. biomechanics the hip joint is unique in that it experiences combined mechanical loads. an axial load along the shaft of the femur results in compressive stress. bending load at the neck of the femur causes tensile stress along the upper part of the neck and compressive stress along the lower part of the neck. while osteoarthritis and osteoporosis are associated with bone fracture as we age, these diseases are not the cause of the fracture alone. low energy falls from standing are responsible for the majority of fractures in the elderly, but fall direction is also a key factor. elderly tend to fall to the side as instead of forward, and the lateral hip and strikes the ground first. during a sideways fall, the chances of hip fracture see a 15-fold and 12-fold increase in elderly males and females, respectively. neurological factors elderly individuals are also predisposed to hip fractures due to many factors that can compromise proprioception and balance, including medications, vertigo, stroke, and peripheral neuropathy. diagnosis physical examination displaced fractures of the trochanter or femoral neck will classically cause external rotation and shortening of the leg when the patient is laying supine. imaging typically, radiographs are taken of the hip from the front (ap view), and side (lateral view). frog leg views are to be avoided, as they may cause severe pain and further displace the fracture. in situations where a hip fracture is suspected but not obvious on x-ray, an mri is the next test of choice. if an mri is not available or the patient can not be placed into the scanner a ct may be used as a substitute. mri sensitivity for radiographically occult fracture is greater than ct. bone scan is another useful alternative however substantial drawbacks include decreased sensitivity, early false negative results and decreased conspicuity of findings due to age-related metabolic changes in the elderly. a case demonstrating a possible order of imaging in initially subtle findings: x-ray showing a suspected compressive subcapital fracture as a radiodense line ct scan shows the same, atypical for a fracture since the cortex is coherent t1-weighted, turbo spin echo, mri confirms a fracture, as the surrounding bone marrow has low signal from edema. as the patients most often require an operation, full pre-operative general investigation is required. this would normally include blood tests, ecg and chest x-ray. types hip fracture classification. subcapital fracture in a 92-year-old woman fracture (black arrow, pertrochanteric) versus a skin fold (white arrow). x-rays of the affected hip usually make the diagnosis obvious; ap (anteroposterior) and lateral views should be obtained. capsule area classification intracapsular femoral head ao 31-c1 – 31-c3 pipkin classification femoral neck subcapital ao 31-b1 – 31-b3 garden classification, pauwel's classification transcervical basicervical extracapsular trochanteric intertrochanteric (between the greater and lesser trochanter) ao 31-a1 – 31-a2 evans' classification (1949), ramadier's classification (1956), boyd and griffin's classification (1949), decoulx & lavarde's classification (1969), ender's classification (1970), tronzo's classification (1973), evans-jensen classification (1975), deburge's classification (1976), briot's classification (1980) pertrochanteric (through the trochanters) ao 31-a3 subtrochanteric ao 32 seinsheimer classification trochanteric fractures are subdivided into either intertrochanteric (between the greater and lesser trochanter) or pertrochanteric (through the trochanters) by the müller ao classification of fractures. practically, the difference between these types is minor. the terms are often used synonymously. an isolated trochanteric fracture involves one of the trochanters without going through the anatomical axis of the femur, and may occur in young individuals due to forceful muscle contraction. yet, an isolated trochanteric fracture may not be regarded as a true hip fracture because it is not cross-sectional. prevention the majority of hip fractures are the result of a fall, particularly in the elderly. therefore, identifying why the fall occurred, and implementing treatments or changes, is key to reducing the occurrence of hip fractures. multiple contributing factors are often identified. these can include environmental factors and medical factors (such as postural hypotension or co-existing disabilities from disease such as stroke or parkinson's disease which cause visual and/or balance impairments). a recent study has identified a high incidence of undiagnosed cervical spondylotic myelopathy (csm) amongst patients with a hip fracture. this is relatively unrecognised consequent of csm. additionally, there is some evidence to systems designed to offer protection in the case of a fall. hip protectors, for example appear to decrease the number of hip fractures among the elderly, but they are often not used. management most hip fractures are treated surgically by implanting a prosthesis. surgical treatment outweighs the risks of nonsurgical treatment which requires extensive bedrest. prolonged immobilization increases risk of thromboembolism, pneumonia, deconditioning, and decubitus ulcers. regardless, the surgery is a major stress, particularly in the elderly. pain is also significant, and can also result in immobilization, so patients are encouraged to become mobile as soon as possible, often with the assistance of physical therapy. skeletal traction pending surgery is not supported by the evidence. regional nerve blocks are useful for pain management in hip fractures. peripheral nerve blocks may reduce pain on movement and acute confusional state, may improve time to first mobilisation, and may reduce the risk of postoperative lower respiratory tract infection. surgery can be performed under general anaesthesia or with neuraxial techniques – choice is based on surgical and patient factors, as outcomes such as mortality and post-procedure complications including pneumonia, mi, stroke or confusion, are not affected by anaesthetic technique. red blood cell transfusion is common for people undergoing hip fracture surgery due to the blood loss sustained during surgery and from the injury. the benefits of giving blood when the hemoglobin is less than 10 g/dl versus less than 8 g/dl are not clear. waiting until the hemoglobin was less than 8 g/dl or the person had symptoms