[Is distal femoral replacement an adequate therapeutic option after complex fractures of the distal femur?].

BACKGROUND: Modular distal femur replacements originally were developed for reconstructing a full weight-bearing and functional extremity after resection of primary bone tumours with large bony defects located in proximity to joints. The aim of this study was to examine the use of the modular distal femur replacements for complex fractures and severe post-traumatic sequelae of the distal femur in context to comparable studies. PATIENTS AND METHODS: Fourteen patients with complex fractures or post-traumatic sequelae and extensive bone defects requiring distal femur replacement were analysed retrospectively. Median age of the patients at the time of distal femoral replacement was 77 years and median follow-up interval was 27 months. Median follow-up was 27.0 (IQB 13.5-37.5) months (range 10-49 months).
RESULTS: The indication for distal femur replacement was a periprosthetic fracture in three cases. Three further periprosthetic fractures were treated with a megaendoprosthesis after failure of osteosynthesis. In eight patients a megaendoprosthesis was implanted due to complications following ostheosynthesis for distal femoral fractures. Distal femoral arthroplasty was performed as a two-stage procedure in five patients with implant-associated infections. A lateral approach was used in six patients and a medial arthrotomy was conducted in eight patients. The median Knee Society score (KSS) improved significantly from 20.0 (IQB 7.5-30.0) points preoperatively to 80.0 (IQB 62.3-89.0) points at follow-up (p < 0.001). Complications requiring surgical intervention were documented in seven of 14 patients (50 %). In two patients wound-healing disorders and superficial infections necessitated surgery. In one patient a rupture of the patellar tendon was diagnosed. This patient subsequently also sustained a periprosthetic fracture. Another patient developed early aseptic loosening of the femoral component. The most common complication was a periprosthetic fracture in four patients. Three patients died for reasons not related to distal femoral replacement.
CONCLUSION: Distal femoral replacement is an important option in reconstituting a full weight-bearing and functional lower extremity after complex fractures and post-traumatic sequelae with massive bone destruction. Particularly elderly patients regain ambulatory ability in the vast majority of cases. The relatively high complication rate demands very thorough preoperative planning as well as prompt allocation of extensive surgical procedures in the case of an adverse event. Georg Thieme Verlag KG Stuttgart · New York.