INTRODUCTION
============

The term 'complex trauma of the foot and ankle' is reserved for fractures that involve severe soft tissue damage associated with neurovascular lesions and joint involvement, which entail a high risk for complications.[@B1] These injuries can also be called: mutilating injuries to the lower extremity, mangled extremity injuries and high-energy lower extremity trauma.[@B2]

Court-Brown and Caesar observed fractures involving the foot and ankle of approximately 12% of a total group of approximately 6000 patients over the period of one year, of which toe and metatarsal fractures represented 85%.[@B3] In a supplementary study, the authors noticed that foot fractures corresponded to 10.5% of all open fractures in almost 2400 open fractures over 15 years.[@B4]

The most common mechanism of injury involved in complex fractures of the foot and ankle is traffic accidents, which represent 49% of causes, followed by falls from heights and work-related trauma.[@B5] The general distribution of foot and ankle fractures, observed by Shibuya et al., reveals 56% ankle, 17% hindfoot, 9% midfoot and 18% forefoot fractures.[@B6]

The World Health Organization reports that every year 1.2 million people die in traffic accidents and more than 50 million are injured.[@B7] The literature shows a high rate of association between complex foot and ankle trauma and polytrauma or multiple injuries between 32% and 52% of the cases, making the treatment of these injuries an even greater challenge.[@B1] ^,^ [@B2] ^,^ [@B8] ^--^ [@B13] Complex trauma of the foot and ankle is a predictor of an unfavorable prognosis in polytraumatized patients and deserves attention and prioritized treatment like diaphyseal fractures of long bones.[@B14] ^--^ [@B23]

In traffic accidents, the upper part of the passenger\'s body is well protected, but the area of the distal third of the lower limb is vulnerable.[@B24] ^,^ [@B25]

Complex foot and ankle trauma is an event that affects the lives of patients, represents a high cost for healthcare systems, and has an impact on the productive activity of countries.[@B24] ^--^ [@B26] This form of trauma often results in some degree of disability, and is therefore a veritable treatment challenge. In this scenario, there is an area not yet adequately defined between injuries that cannot be reconstructed and those where the best outcome is amputation. In this article, we present a literature review and staged management protocol to help in decision making.

Classification Systems
----------------------

Many classification systems have been reported in the literature and can be used in this scenario, such as the Gustilo-Anderson system for open (compound) fractures,[@B27] the Oestern and Tscherne classification for closed fractures,[@B28] the AO soft-tissue injury grading system -- closed skin injuries (IC) / open skin injuries (IO).[@B29]

Zwipp et al.[@B1] ^,^ [@B13] designed a scoring system for ankle and foot injuries to define complex trauma ([Figure 1](#f1){ref-type="fig"}). The foot and ankle are divided into 5 main areas. Each injured area is equal to 1 point, to which points are added based on the severity of the soft tissue injury according to the Oestern-Tscherne Classification, and a score of 5 points or more in the most affected area is considered complex trauma of the foot and ankle. In the hands of a team unused to this kind of trauma, it is more appropriate to regard the lesion as complex, even with a lower total score, and to consider referring the patient to a tertiary orthopedic trauma facility.

![Scoring system for foot and ankle injuries to define complex foot and ankle trauma, according to Zwipp et al.,1,13 with division into 5 areas.](1809-4406-aob-27-04-0223-gf01){#f1}

The MESS (Mangled Extremity Severity Score) system represents an option for deciding between reconstruction and amputation. It is based on four criteria ([Table 1](#t1){ref-type="table"}). When the score is 7 points or above, amputation should be considered.[@B30]

###### Mangled Extremity Severity Score (MESS).

  Skeletal / soft-tissue injury                                score
  ------------------------------------------------------------ -----------------------------------
  Low energy (stab; simple fracture; pistol gunshot wound)     1
  Medium energy (open or multiple fractures, dislocation)      2
  High energy (high speed MVA or rifle GSW)                    3
  Very high energy (high speed trauma + gross contamination)   4
  Limb ischemia                                                
  Pulse reduced or absent but perfusion normal                 1[\*](#TFN1){ref-type="table-fn"}
  Pulseless; paresthesias, diminished capillary refill         2[\*](#TFN1){ref-type="table-fn"}
  Cool, paralyzed, insensate, numb:                            3[\*](#TFN1){ref-type="table-fn"}
  Shock                                                        
  Systolic BP always \> 90 mm Hg                               0
  Hypotensive transiently                                      1
  Persistent hypotension                                       2
  Age (years)                                                  
  \< 30                                                        0
  30-50                                                        1
  \> 50                                                        2

Double the score in cases of ischemia \>6 hours

MESS score: A score above 7 increases the chance of amputation.

Other systems described in the literature are presented in [Table 2](#t2){ref-type="table"}. These limb-salvage scoring scales were designed to reduce subjectivity and provide guidance in the difficult therapeutic decision-making process in complex foot and ankle trauma cases. Ideally, a decision-making system in cases of severe lower limb trauma should be 100% specific and 100% sensitive; however, clinical practice and narrative findings regarding the different systems reveal specificity above 95%, yet sensitivity between 60% and 70%.[@B31] ^--^ [@B40]

###### Predictive scores for limb preservation.

  Score                                                                   Author and year
  ----------------------------------------------------------------------- -------------------------------------------
  Abbreviated Injury Score - AIS                                          AAAM. 1971
  Gustilo classification                                                  Gustilo Anderson 1976; Gustilo et al 1984
  Hannover Fracture Scale-97/98 - HFS-97                                  Tcherne. 1983
  Mangled Extremity Syndrome Index - MESI                                 Gregory et al. 1985
  Predictive Salvage Index - PSI                                          Howe et al. 1987
  Mangled Extremity Severity Score - MESS                                 Johansen et al. 1990
  Limb Salvage Index - LSI                                                Russel et al. 1991
  Nerve injury, Soft-Tissue injury, Skeletal injury, Age Score - NISSSA   McNamara et al. 1994
  Foot and Ankle Severity Scale - FASS                                    Manoli et al. 1997
  The Ganga Hospital Severity Score                                       Rajasekaran. 2005

These scoring systems are of limited use and should not be used as the sole criteria when deciding between amputation and reconstruction. They serve as a tool to facilitate and support a clinical decision.[@B41] ^--^ [@B43]

Treatment Principles
--------------------

The objective of complex foot and ankle trauma treatment is to restore lower limb function, producing a painless, stable and functional lower limb, while avoiding infections, complications, revision surgery and hospital readmission.

First hours after trauma
------------------------

In the emergency unit, a patient with a severe foot and ankle injury should be assessed for all local and systemic parameters and have the treatment algorithm defined:

### 1. Early total care

This type of care should be adopted in selected cases with simple fractures, clean wounds and a team trained in the definitive procedures; when both the patient\'s systemic condition and the local conditions are adequate to support the duration of the procedures and surgical aggression.

Soft tissue management options are:

-   Primary closure

-   Vacuum assisted closure device

-   Fixation in combination with local or microsurgical flap

-   Amputation

### 2. Staged treatment

-   Initial treatment

-   Definitive treatment

Initial Treatment
-----------------

The initial approach to a complex foot and ankle injury has clear objectives and can be divided into 3 parts:

-   Prevent the progression of ischemia and necrosis

-   Prevent infection

-   Decide between amputation and reconstruction.

Part I: Prevent the progression of ischemia and necrosis
--------------------------------------------------------

The first step should be screening for severe trauma and when necessary resuscitation according to the principles of Advanced Trauma Life Support, both during prehospital care and afterwards during in-hospital care.[@B44]

In this scenario, only dislocations and fractures with major deviations that cause impairment of perfusion should be briefly treated, preferably at the site of the accident.

If there are no other life-threatening injuries that require immediate attention, or when the patient has responded adequately to systemic stabilization maneuvers, then the injury to the foot and ankle is assessed and treated.[@B6] The second step is diagnosis through physical examination -- the clinician should assess vascular status (palpable pulses, capillary refill, temperature, and color), neurological impairment (sensitivity, deficient), soft tissue injury (closed or open) and the conditions of bones and joints. Conventional radiographs are sufficient to determine early treatment (e.g., external fixation). Supplementary tests and computed (angio) tomography will be necessary for definitive treatment planning (span-scan-plan principle).[@B45]

At this stage of the treatment, compartment syndrome (CS) should be diagnosed or ruled out.

Characteristic clinical signs include:

-   Tense edema -- has proven the most consistent physical examination finding

-   Progressive pain despite immobilization.

-   Progressive increase in the need for analgesics.

-   Worsening of pain with passive finger mobilization.

-   Diminished discrimination of two points on the plantar aspect of the foot and toes.

The numerical diagnosis of CS occurs when muscle perfusion pressure (difference between diastolic pressure and intramuscular pressure) is less than 30 mmHg.[@B46]

However, if there is strong clinical suspicion and risk factors involved - hypoxia, hypovolemia, vascular injury with peripheral ischemia, high-energy trauma, severe soft tissue injury and complex fractures of the tibia --fasciotomy should be performed. Early fasciotomy is associated with lower rates of morbidity and a better outcome.[@B2]

A medial approach combined with two dorsal approaches over the second and fourth metatarsals is effective in releasing all 9 foot compartments.[@B2]

A single dorsal incision was described and termed Hannover\'s approach, while a single extended medial incision is known as the Henry approach.[@B2]

Kakadia demonstrated that the use of a vessel loop and negative pressure therapy for fasciotomy wound closure results in a higher rate of primary closure and reduces overall healing time ([Figures 2A](#f2){ref-type="fig"} and [2B](#f2){ref-type="fig"}).[@B47]

![Adjunct soft tissue therapy in the treatment of Compartment Syndrome of the feet (A and B) and left leg (C and D). 2A. Immediate postoperative clinical presentation, dorsal view of dermofascietomies combined with the use of Vessel Loop, 2B. Immediate postoperative clinical presentation, medial view of the dermofascietomies combined with the use of the Vessel Loop. 2C. Immediate postoperative clinical presentation, lateral view of dermofascietomies, 2D. Incisional negative pressure dressing, lateral side of the dermofascietomies.](1809-4406-aob-27-04-0223-gf02){#f2}

In addition to the diagnosis and treatment of CS, this sub-phase also includes:

1.  Aggressive debridement using saline lavage and removal of dead tissue and loose bone fragments.

2.  Temporary fixation of the fracture using an external fixator or Kirschner wires to allow:

    -   Inspection and healing of soft tissues

    -   Prevention of equinus deformity

    -   Prevention of infection

The method should permit the inspection of wounds and the application of dressings. The external fixator should be positioned on the most severely injured side in order to preserve the opposite side for the definitive surgical approach.

Indications for temporary stabilization are as follows:

-   Fracture-dislocation with compromised neurovascular structures or skin at risk

-   Unstable open fracture

-   Fracture associated with compartment syndrome

-   Gross instability of the focal point of fracture or of the joint.

Part II: Prevent infection
--------------------------

Open fractures should be quickly covered with sterile dressings in pre-hospital care. Less than 20% of infections in open fractures are caused by microorganisms present at the time of the trauma, and more than 90% of infections are hospital-acquired infections.[@B48] Photographs must be taken to facilitate communication and patient records.

Antibiotic therapy should be initiated as soon as possible. First-generation cephalosporin is usually the first choice. Gentamicin is used in cases of gross contamination or type III open fractures. Consideration should be given to initiating tetanus prophylaxis, and definitive antibiotic therapy or a combination of antibiotics is based on the results of cultures and sensitivity tests.[@B10]

After debridement and initial irrigation, a new surgical approach should be adopted after 24 to 48 hours, depending on the initial contamination and the biological response of the remaining tissues. When there are bone defects secondary to acute bone loss or removal due to infection, necrosis, or gross contamination, these may be used to fill the dead space: gentamicin-impregnated beads, antibiotic-impregnated polymethyl methacrylate or bioactive glass spacer.[@B49] The use of negative pressure therapy in open fractures produces fewer infection-related complications while reducing hospital readmission and revision procedure rates.

In cases where open fracture wounds can be closed primarily following initial debridement, incisional negative pressure therapy aids the healing process ([Figures 2C](#f2){ref-type="fig"} and [2D](#f2){ref-type="fig"}).

On the other hand, early soft tissue coverage has yielded lower rates of infection following complex trauma of the foot and ankle.[@B50]

Part III: Decide between amputation and reconstruction.
-------------------------------------------------------

The combined rate of primary and secondary amputation is around 15% to 30%, depending on the severity of the injury. Primary amputation should be performed in extremely severe limb injuries or in life-threatening injuries, such as in multi-trauma patients with severe comorbidities[@B11] ([Figure 3](#f3){ref-type="fig"}).

![Decision making in amputation. 3A. Dorsal view of the soft tissue and bone injury to the left foot. 3B. Lateral view of the soft tissue injury and bone involvement of the left foot. 3C. Radiograph showing severity of the bone tissue injury. 3D. Anteroposterior radiograph of Chopart amputation, combined with primary arthrodesis. 3E. Lateral radiograph of Chopart amputation, combined with primary arthrodesis. 3F. Clinical presentation of the patient in upright position, with Chopart\'s disarticulation, combined with tibiotalocalcaneal arthrodesis.](1809-4406-aob-27-04-0223-gf03){#f3}

Whenever possible, the patient\'s opinion should be considered in light of the shared decision-making process. However, the final decision is based on the surgeon\'s experience combined with the judgment of the multidisciplinary team, who should be presenting the family and patient to sign the consent form.

The initial absence of plantar sensation is not a reliable predictor, since sensitivity returns in half of the cases. Psychological and social factors have showed themselves to be more important than scoring systems in predicting outcome. Scoring systems should not be the sole criteria on which the amputation decision is based. Everyone must keep in mind that defining reconstruction or amputation is not a prediction of outcome or of function.[@B43]

Amputation
----------

The type of lower limb amputation is widely affected by the level of arterial damage, the level of viable soft tissues, and the quality and contamination of the remaining bone; amputations can be performed at different levels:

Transtibial (below-knee), Syme, Pirogoff, Chopart with tibiotalocalcaneal fusion ([Figures 3D](#f3){ref-type="fig"}, [3E](#f3){ref-type="fig"} and [3F](#f3){ref-type="fig"}), Chopart combined with transfer of the tibialis anterior tendon to the neck of the talus neck and with percutaneous calcaneus tendon lengthening, and finally, transmetatarsal amputation preserving all the principal tendon insertions around the foot and ankle.

The main objective is survival while the secondary objective is to provide the best quality of life possible.

The principles of an amputation are:

-   Identification and adequate treatment of nerves and vessels.

-   Stable myodesis, guaranteeing robust soft tissue coverage.

-   Preserve the balance of muscles and tendons.

-   Preserve the length of the limb when feasible

-   Multidisciplinary team approach throughout the treatment period

Reconstruction
--------------

The timing of definitive treatment with reconstruction depends on the systemic state of the patient and the soft tissues.

The principles of the reconstruction procedure are:

1.  First bone tissue

    -   From proximal to distal

    -   When the patient has a fracture of the talus and distal tibia -- first talus before the tibial pilon or ankle.

2.  Anatomical reconstruction of axial alignment and functional columns of the foot.

3.  Primary fusions for severe cartilage injury or gross instability

4.  Stable internal fixation

5.  Early and stable soft tissue coverage

Early flaps for soft tissue reconstruction allow lower rates of infection following open fractures and functional rehabilitation.

The selection of the flap should take into account: minimal morbidity in the donor area, needs of the recipient area and familiarity of the surgeon ([Figure 4](#f4){ref-type="fig"}).

![Example of foot reconstruction in complex injuries. 4A. Initial clinical image of the soft tissue injury, 4B. Initial AP radiograph of the ankle and oblique x-ray of the foot, showing tarsometatarsal dislocation-fracture with extrusion of the intermediate cuneiform, 4C. Anteroposterior radiograph after debridement, stabilization of the first, third and fifth radial bones, disimpactation of the cuboid and bone fragment interposition using an antibiotic-impregnated cement spacer in the intermediate cuneiform topography, 4D. Lateral radiograph after debridement, stabilization and bone fragment interposition using an antibiotic-impregnated cement spacer in the intermediate cuneiform topography, 4E. Immediate postoperative clinical presentation following debridement, stabilization and approximation of soft tissues for application of negative pressure dressing, 4F. Intraoperative clinical presentation − 72 hours after the first procedure -- filling of bone fragment with autologous bone graft (iliac crest) and definitive fixation of the second radial bone, 4G. Lateral radiograph after definitive treatment 4H. Anteroposterior radiograph after definitive treatment, 4I. Planning of sural rotation flap posterior view, 4J. Planning of rotation flap lateral view, 4K. Final clinical presentation of skin coverage with rotation flap posterior view, 4L. Final clinical presentation of skin coverage with rotation flap lateral view.](1809-4406-aob-27-04-0223-gf04){#f4}

The most commonly used flaps for the treatment of complex foot and ankle are:

1.  anterolateral thigh flap

2.  dorsalis major

3.  rectus abdominus

4.  gracilis

The outcome expectation consists of 6 aspects:

-   final function of the locomotor system

-   local aesthetics and remaining volume

-   pain and loss of sensitivity

-   total treatment time

-   costs of hospitalization

-   emotional factors

Functional results - locomotor system
-------------------------------------

A prospective multicenter study investigated the functional outcomes of 569 patients with severe lower limb injuries, resulting in reconstruction or amputation. In two years of follow-up, there was no significant difference between the amputation and reconstruction groups for the scores and time to return to work. The patients who underwent reconstruction had a higher rate of hospital readmission.[@B34]

Quality of life in post-traumatic amputees in comparison to limb reconstruction was evaluated in a meta-analysis. The authors demonstrated that lower limb reconstruction is more psychologically acceptable for patients with severe trauma as compared to amputation, although the physical outcome for both treatment options is the same.[@B51]

A prospective longitudinal study determined the outcome of complex foot and ankle injuries undergoing limb reconstruction surgery requiring free flaps compared to a similar group of patients who underwent early amputation at the level of the proximal tibia. The authors concluded that the patients requiring free flap transfer had significantly worse scores than the amputees.[@B52]

An amputation usually involves a shorter hospital stay, fewer surgical procedures, and faster total rehabilitation. The costs of the prosthesis are higher and the rehabilitation process more lengthy, depending on the patient\'s age at the time of the injury.[@B53]

In the US, the prevalence is 80,000 new amputees/year, with a treatment cost per amputee in the first two years of US\$ 91,106, vs US\$ 81,316 per patient treated with reconstruction. The cost of lifetime medical care per amputee is US\$ 509,275 vs US\$ 163,282 per patient treated with reconstruction.[@B53]

Two comparative cohort studies, one made up of civilian patients and the other of military patients, evaluated severe isolated injuries of the foot and showed inferior functional results in the groups undergoing reconstruction in both studies. The groups of authors observed higher rates of complications and need for revision surgery, as well as longer hospitalization and rehabilitation times in the groups undergoing reconstruction.[@B54] ^,^ [@B55]

Consideration must be given to an important bias in this area of knowledge. While the amputation technique has been performed and improved over the last 300 years, reconstructive surgery for complex foot and ankle injuries has been under development for the past 3 decades.

FINAL CONSIDERATIONS
====================

There have been considerable developments in the treatment of complex foot and ankle injuries over the last three decades. The final functional outcome needs to be projected right from the start of the treatment. Although saving the limb may be psychologically better in principle, a stiff, painful and/or insensitive, nonfunctional foot may represent a much worse outcome with the need for secondary interventions and prolonged hospitalization and rehabilitation. Treatment should be individualized based on patient characteristics and local conditions. If the necessary tools are not available, referral to a specialized service should be considered. If the surgeon opts for ankle and foot reconstruction, stable internal fixation and early soft tissue coverage followed by an aggressive rehabilitation protocol and appropriate footwear modifications should be implemented to achieve maximum functional recovery. Complex foot injuries are hard to treat and may require an extended follow-up period with specialist care.

Stefan Rammelt - Universitätsklinikum Carl Gustav Carus, Germany. Marcos Hideyo Sakaki - Universidade de São Paulo, Brazil. Cristián Ortiz Mateluna - University of Desarrollo, Chile. Rafael Barban Sposeto - Universidade de São Paulo, Brazil. Panagiotis Symeonidis - St. Luke\'s Hospital, Greece. Rogerio Bitar - Hospital for Special Surgery, USA. Husam Darwish - King Abdulaziz University Hospital, Saudi Arabia. Hans Zwipp - Universitätsklinikum Carl Gustav Carus, Germany.

Work conducted at the Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Department of Orthopedics and Traumatology (DOT/FMUSP), São Paulo, Brazil, and by the Soft Tissue Foot & Ankle Group.

[^1]: All authors declare no potential conflict of interest related to this article.

[^2]: **AUTHORS\' CONTRIBUTIONS**: Each author made significant individual contributions to this manuscript. ALGS (0000-0002-6672-1869)\* conception and design of the study, writing of the article. TS (0000-0003-1172-4939)\* contributed to the interpretation of data and critical review. SR (0000-0003-1141-6493)\* contributed to the analysis and interpretation of data. MHS (0000-0001-7969-0515)\* contributed to the acquisition of data, analysis and interpretation of data. CO (0000-0003-3087-9506)\* contributed to the review. RBS (0000-0003-1085-0917)\* contributed to the acquisition of data. PS (0000-0002-5762-7627)\* contributed to the conception and design of the study. RB (0000-0003-3199-4055)\* contributed to the interpretation of data and critical review. HD (0000-0003-2176-3763)\* and HZ (000-0002-0194-6493)\* contributed to the critical review. \*ORCID (Open Researcher and Contributor ID).
