Bumper Fracture of the Knee
In 1929, Cotton and Berg1 coined the name bumper fracture for the injury caused by the impact of the automobile bumper against the outer aspect of the extended knee. Their definition reads in part: “This is the fracture of the outer side of the tibial head, produced by abduction of the leg forcible enough to smash the external tuberosity against the fulcrum of the outer condyle of the femur.” Many articles have been written on this subject since then, but there still exists considerable difference of opinion as to the most desirable method of treatment. In this brief communication we wish to discuss some of the problems involved and outline a plan of treatment that has aided us materially in preventing the knock-knee deformity which so commonly occurs.
The violence sustained is of the crushing type and, if severe, leaves the knee with a squashed, depressed, comminuted, external tibial condyle. On examination, the most characteristic finding is the marked lateral instability of the joint which permits the leg to be abducted on the thigh to a varying extent. The external semilunar cartilage may be dislodged or even forced down between the condylar fragments. The tibiofibular joint is disrupted and the head of the fibula is sometimes crushed. The external and internal lateral ligaments are torn or remain intact, depending on the severity of the injury.
Many different methods of reduction, both open and closed, have been devised. In principle, all these seek to obtain restoration of an even tibial articular. . .