Boots Are Not Made for Driving: A Cautionary Case Report About the Dangers of Driving in a CAM Walker Boot and Literature Review

Case Report

A 41-year-old man was originally referred to our institution with symptomatic failure of his calcaneal open reduction and internal fixation (Figure 1). After undergoing a successful distraction subtalar arthrodesis, he later developed early adjacent segment disease in his talonavicular and calcaneocuboid joints. The patient failed nonoperative management and eventually had these joints arthrodesed with the addition of Augment Bone Graft (Augment Injectable Bone Graft, Wright Medical Wright Medical Technology, Franklin, TN). Two weeks postoperatively, the patient was placed into a CAM walker boot and instructed to remain nonweightbearing.

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Figure 1.

(A) Weightbearing lateral radiograph of the foot showing failure of hardware and loss of Bohlers angle. (B) Sagittal hardware suppression protocol computed tomography image of the foot demonstrating the collapse of the posterior facet with degenerative change at the calcaneocuboid joint.

Unfortunately, 2 weeks later, the patient was involved in a serious motor vehicle accident, directly caused by his CAM walker boot becoming entrapped between the accelerator and brake pedal. This CAM boot entrapment resulted in the patient, who was an unrestrained driver, colliding with a tree. He was noted to have immediate onset of quadriparesis, and on arrival at the emergency department was found to have a complete spinal cord injury at the C6 level. Computed tomography (CT) and magnetic resonance imaging (MRI) confirmed a C6/7 fracture dislocation of the cervical spine with severe cord edema and compression (Figure 2). He was treated with emergency anterior cervical discectomy and fusion with tricortical iliac crest bone graft with a supplemental C6 laminectomy and C5-7 posterior instrumented fusion (Figure 3). Six weeks post his spinal surgery, the patient had not experienced any clinically significant neurological recovery.

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Figure 2.

A sagittal T2 magnetic resonance image demonstrating the C6/7 dislocation with cord compression and edema.

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Figure 3.

A lateral radiograph of the cervical spine demonstrating the anterior cervical discectomy and fusion and posterior laminectomy and instrumented fusion with lateral mass screws.

Discussion

Despite “When can I drive?” being one of the most common questions asked by patients undergoing lower extremity surgery, it remains a very challenging and difficult question to answer for orthopaedic surgeons, with more than two-thirds feeling uneasy about counseling patients about the issue for a variety of clinical, ethical, and medicolegal reasons, and 10% refusing to advise patients at all.^14,15 There is also a lack of accepted professional guidelines, and heterogeneity between road regulations, law enforcement agencies, and insurance companies compounding the difficulty in advising patients. ¹⁶ Currently, neither the American Academy of Orthopaedic Surgeons nor any other orthopaedic specialty society has endorsed recommendations, policies, or practice guidelines that address how the decision about returning to driving should be made, who should be involved, or to what extent retesting of driving abilities after an injury should be required. ² This is compounded by geographical differences in regulations, with several North American states currently having no specific prohibition of or allowance for driving while their lower extremity is immobilized. ³

In an attempt to provide some clarity and tenable evidence when counseling patients on a safe return to driving, multiple experimental studies using driving simulators have been undertaken to look at emergency braking times after a variety of lower limb surgeries.^5,6,8-12 However, only 2 studies have looked specifically at the impact of immobilization with either CAM boots or plaster.

In one study involving healthy individuals using a driving simulator, CAM boots significantly increased both braking reaction times and total braking time when compared with both short leg casts and running shoes. ¹³ These findings were replicated by Orr et al, ³ who also found that the CAM boot group performed the worst. Orr et al ³ extrapolated that the difference in braking times in the CAM boot group would result in travel of an additional 9.2 ft (2.8 m) when traveling at highway speeds of 60 mph (96.6 km/h), and if traveling at a community speed of 35 mph (56.3 km/h) would result in travel of an additional 5.4 ft (1.6 m). ³

Unfortunately, these studies looking at CAM boots have inherent weaknesses in that they are conducted on healthy controls and in simulated driving conditions. These studies cannot accurately assess the complex interplay of integrated neurologic, physical, and cognitive skills that the task of driving in real-life scenarios requires, with unexpected dangers, in different weather and lighting conditions.^2,5 Furthermore, the studies have only looked at braking times, and have not explored entrapment of the CAM boot between or underneath car pedals, as was the issue in this case report. Finally, the studies are difficult to extrapolate and use as an educational tool for patients, who are more likely to not only comprehend but also take notice of a relatable and serious example of why you cannot drive in a CAM boot. This case report is a useful educational tool and real-life example for both surgeons and patients about the dangers of driving while immobilized in a CAM boot.

Further complicating the difficulty in communicating the risk of driving in a CAM boot to patients is a lack of medical industry manufacturer warnings. In an audit of the CAM boots utilised at our institution, only one of three contained an explicit warning against operating a motor vehicle in the enclosed product information brochure.

From a medicolegal and risk management perspective, we recommend that all CAM walker boots should come with explicit warnings to not drive, and from an orthopaedic surgeon’s perspective, we recommend that this advice should be clearly stated and documented throughout the patient’s perioperative and rehabilitative period, independent of local legislature and in the absence of formal policies, guidelines and recommendations.