Minimally invasive plate osteosynthesis with dual plating for periprosthetic distal femoral fractures following total knee arthroplasty.

Abstract

Adequate treatment for periprosthetic distal femur fractures is challenging because of various reasons, including severe osteoporosis and distal fragments that are too small or too distal. We have introduced a new surgical technique for dual plating of periprosthetic distal femur fractures following total knee arthroplasty (TKA) and determined the clinical and radiological outcomes of minimally invasive plate osteosynthesis (MIPO) with a dual locking compression plate (LCP). Between January 2010 and July 2019, 18 patients [mean age, 74.8 (68-89) years; average follow-up period, 14.8 (12-43) months] underwent MIPO with distal femoral LCP laterally and proximal humeral internal locking system (PHILOS) medially for periprosthetic distal femoral fractures following TKA. The minimum follow-up was 1 year. The clinical and radiological outcomes were assessed using the modified WOMAC scores, knee range of motion, time to callus formation, time to union, and complications of malunion, nonunion, and shortening. The average time to union was 18.4 weeks (range, 10-51 weeks) and to callus formation was 7.8 weeks (range, 2-14 weeks). At the 1-year follow-up, the average JLETS was 37.6 (range, 24-53), average knee ROM was 110.3° (range, 80-135°), and average varus-valgus angles of the distal femur were 3.2° (range, -2.9-10.5°). No nonunion, broken plates, or implant failure occurred. Malunion occurred in three patients. MIPO with dual LCP is a reliable method for stabilizing periprosthetic distal femoral fractures following TKA, with satisfactory bone union rates and low complication rates.