Wheelchair-related thumb injury of multifactorial etiology: a case report.

A 56-year-old man presented with bilateral transtibial amputations secondary to peripheral vascular disease and diabetes. While using a hospital-owned wheelchair to descend a 27-m-long, 5.6 degrees slope in an underground tunnel connecting the rehabilitation center to a neighboring acute care facility, the patient had difficulty slowing the wheelchair to negotiate a turn. After sustaining burns on the palmar aspects of the thumbs due to friction against the metal handrims, he shifted his thumbs onto the treaded tires. This pulled his right thumb between the wheel lock and the tire of the wheelchair. The resulting laceration and small chip fracture of the dorsal aspect of the thumb metacarpal required immobilization. This injury might have been prevented if the ramp had not violated accessibility guidelines, if the handrims and wheel locks had been different, if brakes had been available, if the patient had been wearing gloves, and/or if the patient had used appropriate procedures for descending long, steep inclines. This case has several implications for the wheelchair-delivery system.