Outcome of periprosthetic femoral fractures following total hip replacement treated with polyaxial locking plate.

Abstract

The number of patients with total hip replacement (THR) is likely to grow. Periprosthetic femoral fractures occur in 0.1-4.5 % of patients with THR. Treatment of periprosthetic fractures in the vicinity of well-fixed implants has focused on lateral plating. The purpose of this study was to evaluate polyaxial locking plate treatment of periprosthetic fractures with THR in regard to fracture type, surgical procedure, complications, and outcome. Between 2007 and 2013, 109 patients underwent surgical treatment for periprosthetic femur fractures with 66 fractures in the vicinity to a THR. Fifteen patients were excluded. Therefore, 51 patients with a mean age of 78.7 years were identified. There were 76.5 % females. Average BMI was 27.1 kg/m². Follow-up averaged 25 months. Total hip stems were uncemented in 63 %. Low-energy mechanism predominated. Fractures were classified according to AO/OTA and Vancouver classifications with the majority (70.6 %) classified as AO/OTA type A fractures. Surgeries were performed utilizing a polyaxial locking plate. Complications were recorded concerning infection, union, fixation failure, and revision surgery. After the index procedure, 90.2 % healed. Non-union formation was diagnosed in 5.9 % with 2.0 % leading to hardware failure. All patients with non-union formation had interprosthetic fractures (χ ² = 0.016). Additionally, these fractures were classified as AO/OTA type B fractures (χ ² = 0.003). Surgical management despite polyaxial locked plate fixation continues to be challenging and may still result in non-union formation. Non-union formation is increased in AO/OTA type B fractures and related to interprosthetic fractures. Level IV.