Outcomes of knee arthroplasty for primary treatment of pathologic peri-articular fractures of the distal femur and proximal tibia

Background Treatment goals for pathologic fractures about the knee include pain relief and unrestricted weight bearing. In cases of condylar destruction, these fractures may not be amenable to internal fixation, and arthroplasty may be considered. The purpose of this study was to analyze the outcomes of knee arthroplasty for primary treatment of impending or pathologic fractures of the distal femur or proximal tibia. Methods Fifteen (8 males and 7 females) patients, mean age 62 +/- nine years, undergoing arthroplasty for management of a pathologic peri-articular distal femur (n = 11) or proximal tibia (n = 4) fracture between 2001 and 2017 were reviewed. Implants included tumour endoprostheses (n = 11) and rotating hinged total knees (n = 4). Pathology included metastatic disease (n = 14) and lymphoma (n = 1). Eight (53%) patients presented with a fracture while the remainder had large impending lesions. Results Mean follow-up was 19 months. At final follow-up, 11 patients had died with overall five year survival of 33%. Two (13%) patients required re-operation; including wound irrigation and debridement (n = 1) and above knee amputation for local recurrence (n = 1). An additional two (13%) patients developed post-operative VTE. MSTS, KSS, and KSS-F scores improved from a mean 12 +/- 16%, 30 +/- 11, and 14 +/- 24 pre-operatively to 69 +/- 26%, 75 +/- 16, and 67 +/- 25 at final follow-up, respectively (P < 0.001). Thirteen (87%) patients had severe pain prior to surgery with no patients (0%, P < 0.001) reporting severe pain at last follow-up. Conclusion Knee arthroplasty provided improved function and full weight-bearing making it an effective treatment for pathologic periarticular fractures of the distal femur and proximal tibia.