Crushed Foot

Introduction

Crush injuries to the foot are a rare occurrence and often result from major trauma. They occur as a result of direct compression between two hard surfaces.

They can be life-changing injuries with chronic pain, stiffness, deformity or amputation as potential outcomes. It is important that the patient is aware of poor prognosis from the outset with the spectrum of severity and associated injuries vary depending on the mechanism involved. 

Early Management

The crushed foot is comprised of bony and soft tissue elements and the force involved in the injury initially leads to muscle ischaemia followed by necrosis. The goals of early management should be to:

  • Reduce ischaemia and tissue necrosis
  • Prevent infection and decide whether or not the foot is salvageable

Initially treat the polytrauma patient in accordance with ATLS guidelines and treat life-threatening injuries as a priority. Early involvement of Plastic Surgeons is essential in extremity crush injurie and these injuries should be managed in a Major Trauma Centre. If such injuries present to a hospital without the necessary specialties on site, consider onwards referral to a trauma centre as per BOAST.

Provide adequate analgesia for the patient and elevate the affected limb to reduce swelling and perform a thorough assessment of the soft tissues – including documented neurovascular status – and take photographs on a Trust-agreed device; this allows visualisation of the injuries by others without the need for removal of dressings or casts. Gross contamination should be removed from any open wounds prior to applying saline-soaked dressings; commence intravenous antibiotics to reduced infection risk. Be mindful of degloving injuries, even if the skin remains intact post trauma; these can result in soft tissue necrosis by separation of the subcutaneous tissues from their attachments and blood supply; it can take time for the full extent of the injury to declare itself. To assess the full extent of the patient’s injuries, an appropriate trauma scan should be performed once the patient is stable; this can be extended to include the injured foot if the patient’s clinical state allows. Regarding bony injuries, reduce any obvious dislocations affecting perfusion as early as possible and temporary stabilisation will often be required to allow the soft tissues to settle and to provide analgesia; options include splint / plaster, K-wires or an external fixator.

A high index of suspicion for compartment syndrome is required as crush injuries have been shown to be the main cause of isolated foot compartment syndrome. Damage to the soft tissues can be classified by the Tscherne–Oestern classification of closed skin injuries or the Gustilo Anderson Classification. In most cases of major trauma, crush injuries will be a Tscherne 3 or Gustilo Anderson III b/c.

 

Tscherne-Oestern Classification

Tscherne Classification

Soft tissue

Fracture

Grade 0

No or minor soft tissue damage

Indirect injury with simple fracture

Grade 1

Superficial abrasion or skin contusion

Medium severity fracture pattern

Grade 2

Deep abrasion with muscle contusion

Severe fracture pattern by direct trauma

Grade 3

Extensive muscle contusion, crush injury with severe damage to underlying muscle;

Compartment syndrome, Morel-Lavalle and / or vascular injury

Complex fracture patterns

 

Gustilo and Anderson Classification of Open Fractures

Gustilo & Anderson Classification

Wound

Soft tissue (ST)

Fracture

I

<1cm clean wound

Minimal ST damage

Simple fracture pattern

II

wound 1 – 10cm

Moderate ST damage with no loss / crush

Simple fracture pattern

IIIa

>10cm, adequate coverage

Extensive ST damage

Complex fracture

IIIb

>10cm, insufficient coverage

Extensive with ST loss and contamination

Complex pattern with periosteal stripping

IIIc

>10cm, insufficient coverage

Extensive with ST loss and contamination with associated arterial injury

Complex fracture

 

*awaiting image upload*

Figure 1: Zwipp classification of complex foot injuries. A severity scoring system based on a comnbination of location and Tscherne score.

Definitive Treatment

The goals of definitive treatment are to restore function in terms of a painless, plantigrade foot that can fit in a shoe. Decisions as to whether or not the foot is salvable should be made as part of a multidisciplinary team involving the patient, bearing in mind their co-morbidities and expectations. Amputation rate can be as high as 30% in complex injuries, and soft tissue injury is one of the biggest influences on this. Many scoring systems exist to help decision-making on extremity salvage, but none are 100% sensitive and specific.

The Lower Extremity Injury Severity Score study (LEAP) looked at 5 different scoring systems in over 600 patients but could not support the use of any; scores were useful in predicting limb survival but not amputation. There was no difference in functional outcomes at 2 and 7 years post injury between subjects who underwent amputation or salvage surgery, but both were poor.

Amputation

Aims are to:

  • Preserve length depending on extent injury
  • Restore maximal function
  • Prevent pain/neuroma formation
  • Allow prosthesis and early rehabilitation

It should be considered as an option for definitive treatment if the limb is not salvageable. Patients undergoing salvage surgery require more surgery, have higher re-hospitalisation rates and, in cases where it fails, would have opted for earlier amputation if they had the choice again.

Levels at which amputations may occur:

  • Transmetatarsal
  • Midfoot (Lisfranc)
  • Hindfoot (Chopart/Boyd)
  • Ankle (Symes)

Reconstruction

Reconstruction is best performed by an experienced trauma / foot and ankle surgeons with the presence of plastic surgeons to provide soft tissue coverage at the time of metalwork insertion. Fixation occurs proximal to distal, with the exception of talus before ankle/pilon. The aim is to restore normal anatomy with regards to length, columns and arches. Arthrodesis should be considered in complex intra-articular fractures, and importantly nerves do not recover well following crush injuries.

Conclusions

  • These are devastating injuries with poor outcomes and long-term implications for patients; disability rates are as high as 40% after complex foot trauma
  • Early outcomes are best predicted by the extent of soft tissue injury
  • Amputation may be required in as high as 30% of patients
  • Severe injuries should be managed in a Trauma Centre with the appropriate specialties through a multidisciplinary team approach

References

  • Schepers T, Rammelt S. Complex Foot Injury: Early and Definite Management. Foot Ankle Clin. 2017;22(1):193-213
  • Godoy-Santos AL, Schepers T; Soft Tissue Foot & Ankle Group. Soft-tissue injury to the foot and ankle: literature review and staged management protocol. Acta Ortop Bras. 2019;27(4):223-229. doi:10.1590/1413-785220192704221240
  • MacKenzie EJ, Bosse MJ, Kellam JF, et al. Factors influencing the decision to amputate or reconstruct after high-energy lower extremity trauma [published correction appears in J Trauma 2002 Jul;53(1):48]. J Trauma. 2002;52(4):641-649. doi:10.1097/00005373-200204000-00005
  • Bosse MJ, MacKenzie EJ, Kellam JF, Burgess AR, Webb LX, Swiontkowski MF, et al. An analysis of outcomes of reconstruction or amputation of leg-threatening injuries. N Engl J Med. 2002;347:1924–31