Comparison of the mechanical performance of trochanteric fixation devices.

The transtrochanteric surgical approach to the hip is commonly used, especially for revision hip surgery. Failure of the trochanter to heal can lead to hardware failure, persistent pain, and limp. Rigid internal fixation is needed in this approach to achieve an adequate rate of healing. Newer cable and cable grip systems have been designed to improve trochanteric fixation, but have not been compared to the older Charnley wire fixation techniques. In this study, an in vitro mechanical method previously used to test wire fixation methods was used to compare wire, cable, and cable grip fixation methods. A quasistatic mechanical distraction device was used to compare structural stiffness, load to clinical failure, energy to clinical failure, and maximum load resisted by the fixation devices. The cable grip system was found to be stiffer, to resist a larger load to mechanical failure at 1-cm displacement, and to absorb a greater amount of energy to clinical failure when compared with the other systems. These data suggest that use of the cable grip fixation method should result in improved clinical success compared with the Charnley wire technique.

The versatility of the gastrocnemius muscle flap.

The gastrocnemius muscle rotation flap is a utilitarian procedure for management of soft-tissue defects about the knee. Ten patients underwent medial gastrocnemius muscle rotation flaps at our institution during a 24-month period. Four of the 10 patients underwent primary muscle rotation-plasty for reconstruction following tumor resection; 3 patients had soft-tissue defects following trauma; 2 patients had skin ischemia following total knee arthroplasty; and 1 patient had a soft-tissue defect from scar formation. All procedures were performed by an orthopaedic surgeon. At follow-up of 6 to 24 months, the soft-tissue coverage was maintained in all patients. All of the muscle rotation flaps survived. The gastrocnemius rotation flap provides reliable anterior knee soft-tissue coverage and can be performed by most orthopaedic surgeons.