KNEE DISLOCATION ASSOCIATED WITH IPSILATERAL FEMORAL SHAFT FRACTURE: A RARE INJURY WITH SIGNIFICANT MORBIDITY

Abstract

Introduction: Knee dislocations are uncommon injuries with most series reporting only few cases over a period of many years. The association of knee dislocations with femoral shaft fractures is exceedingly rare and further complicates the management of this injury. We describe four patients managed at our tertiary care trauma center and evaluate the outcome.

Patients and Methods: Out of 187 femoral fractures treated in our institution over a period of 6 years (1994–1999), 4 patients with 5 femoral fractures and ipsilateral knee dislocations were identified. All four patients (2 female) were in early twenties and involved in high energy road traffic accidents. One woman had bilateral knee dislocation with fractures of both femora and tibiae. None of these four patients had head, chest or major visceral injury. No patient had neurovascular damage or compartment syndrome. All were managed by immediate relocation of the knee, angiography, locked intramedullary nailing of femur and post-operative bracing of the knee for six weeks – either by external fixator or hinged brace. Following discharge from the hospital they were followed up regularly in the fracture clinic. Secondary reconstructive procedures were planned depending on the severity of injury and patient demands. The minimum follow up was two years.

Results: Four of five femoral fractures united within expected time scale. One with nonunion had exchange nailing twice and is presently under follow up. Out of the five knees, four underwent a secondary reconstructive procedure. One patient had an open dislocation of the knee with loss of quadriceps tendon, part of patella and patellar tendon, which was reconstructed with Leeds-Keio ligament strips and a free flap. One other patient required an ACL reconstruction two years after injury and finally had a stable painless knee. The lady with bilateral injury had reconstruction of both PCL 2 years after injury. At the final follow up seven years later, there was residual PCL laxity in one knee and she was mobile with one stick. At final follow up all the patients were assessed by the American knee score.

Conclusion: Femur fractures with knee dislocations are orthopaedic emergencies. These injuries should be treated by immediate relocation of the knee, stabilization of the femoral fracture and ensuring normal distal circulation. In our patients, we have braced the knee initially and symptomatic instability was later on managed by appropriate ligament reconstruction procedures. Cross instability may require application of bridging external fixator to facilitate knee ligament healing. Two patients in this series had a good outcome with stable painless knees. The treatment has to be individualized in each situation to achieve an optimum result.