Evaluation And Management Of Crush Injuries Of The Foot

Co-authored by Sheena Niese, DPM

Crush injuries of the foot can present with complex, difficult to manage deformities and fractures. We can define these as any injury occurring from an extrinsic compressive or shear force of variable magnitude applied to the foot over a variable period of time.¹ These are serious injuries with the potential for amputation. Understanding the mechanism of injury and providing expeditious treatment are key to obtaining favorable outcomes.

Initial evaluation should include a thorough history and physical. Perform a thorough history and physical examination on all patients presenting with musculoskeletal trauma. It is important to note patients’ past medical history, including the presence of diabetes and vascular disease as these diseases can have a significant affect on healing. Initiate tetanus prophylaxis if necessary. Pay special attention to the neurovascular status and soft tissue envelope.¹ Closely monitor any contusions, abrasions, lacerations or degloving for signs of necrosis.¹ Furthermore, if the patient is able to relate a detailed history of the incident, it can provide valuable insight into the mechanism and extent of injury.

We can classify crush injuries based on the system proposed by Vora and Myerson.¹ Their classification system is summarized in the table below.

The clinician should maintain a high index of suspicion for compartment syndrome. Researchers have reported that crush injuries result in the highest incidence of compartment syndrome in the foot.² Compartment syndrome occurs in 2 to 12 percent of all lower extremity trauma and one must rule this out.³ It results from an increase in the interstitial pressure combined with a decrease in the capillary blood flow, ultimately leading to decreased perfusion pressure and inadequate tissue blood perfusion.³ Compartment syndrome may present with pain out of proportion to the injury, paresthesias, pallor, pulselessness and paralysis. Definitive diagnosis occurs with a wick catheter reading of at least 30 mmHg or a reading 10-30 mmHg below the diastolic blood pressure.^1-3 If one confirms a positive diagnosis, prompt fasciotomies must follow.

Understanding the zone of injury is critical to surgical planning. With crush injuries, the damage is often much worse than is immediately apparent.¹ Thus, understanding the zone of injury that exists beyond the initial injury site is crical. This is an area of soft tissue and/or bone that was not directly impacted, but succumbs to pathologic changes. In a crush type injury, soft tissue and skin necrosis may extend well beyond the area of impact.¹ This becomes important in surgical planning as it is easy to underestimate the extent of the damage.

Surgical debridement is often unavoidable in crush type injuries but one must employ meticulous soft tissue handling.³ Perform debridement and irrigation as soon as possible. This may require multiple debridements to obtain a clean wound. Soft tissue coverage of wounds is vital to limb salvage and allows for a lower failure rate and decreased infection rate.¹ In addition, performing early soft tissue coverage will lead to fewer surgical procedures, an increased rate of bone union and shorter hospital stay.¹

A Closer Look At A Patient With A Crush Injury

A 48-year-old male patient presented to the emergency department within an hour of sustaining a crush injury to his foot at work. He was alert and oriented with an overall pleasant demeanor despite the condition of his foot. The patient related a history of a 47,000-pound metal object falling on his foot. He stated this remained on his foot for several minutes while awaiting the arrival of a forklift to remove the object. The patient admitted to wearing steel toe boots when this occurred. He denied any other injuries and any loss of consciousness. The patient was also able to relate that the more proximal part of his foot was spared from the crush injury by the way the object was shaped and landed.

The patient’s past medical history was non-contributory. He denied any significant past medical history. He did admit to being a current everyday smoker and to smoking one pack of cigarettes a day for many years.

Despite the significant trauma sustained to his foot, his dorsalis pedis and posterior tibial pulses remained palpable at +2/4. His light touch sensation was intact to his plantar forefoot. Compartment syndrome did not appear to be a complication in this scenario because of the open nature of his injury and the sparing of his midfoot and ankle from injury. Upon presentation to the emergency department, blood loss was minimal given the extent of the injury. There was no pulsatile bleeding. As visible in the photos, his skin had already begun to demarcate via ecchymosis and early necrosis. The patient sustained partial amputations of the second, third and fourth digits with multiple comminuted open fractures. We would classify this as Vora and Myerson Type II injury.

Prophylactic parenteral antibiotic use consisting of cefazolin and gentamicin began in the emergency department. Additionally, the patient received tetanus prophylaxis. After discussing all possible treatment options with the patient, we agreed to proceed with a transmetatarsal amputation. The patient presented to the emergency department having had nothing by mouth (NPO) since dinner the evening before, which allowed him to go to surgery within several hours of the injury. We thoroughly debrided the wound and flushed it intraoperatively with copious amounts of normal sterile saline. The lead surgeon felt there was enough healthy skin to perform a primary closure. We left a Penrose drain in place to allow drainage over the next several days. The patient stayed overnight in the hospital for observation and was discharged home the next day.

At a subsequent follow-up in the office, the patient demonstrated multiple fracture blisters to the dorsum of his foot. The incision site remained intact with some necrotic changes to the dorsal and lateral aspect. The fracture blisters had drainage and cleansing with betadine. We will continue to monitor the patient closely over the next several weeks to months until complete resolution of his wounds occurs.

Dr. Niese is a second-year resident at Alliance Community Hospital in Alliance, Ohio.

References

1. Vora A, Myerson MS. Crush injuries of the foot in the industrial setting. Foot Ankle Clin. 2002; 7(2):367-383.
2. Thakur NA, McDonnell M, Got CJ, et al. Injury patterns causing isolated foot compartment syndrome. J Bone Joint Surg Am. 2012; 94(11):1030-1035.
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6. Hong CC, Nashi N, Kuan WS, et al. Forklift-related crush injuries of the foot and ankle. Foot Ankle Int. 2015; 36(7):806-811.
7. Thomas JL, Blitch EL 4^th, Chaney DM, et al. Diagnosis and treatment of forefoot disorders. Section 5. Trauma. J Foot Ankle Surg. 2009; 48(2):264-272.
8. Bingham AL, Fallat LM. Empty toe phenomenon: a rare presentation of closed degloving injury of the foot. J Foot Ankle Surg. 2016; 55(4):842-849.
9. Sexton SE. Open fractures of the foot and ankle. Clin Podiatr Med Surg. 2014; 31(4):461-486.
10. Schepers T, Rammelt S. Complex foot injury: early and definite management. Foot Ankle Clin N Am. 2017; 22(1):193-213.