Anterior Locking Plate Osteosynthesis of Patellar Factures - Analysis of Complications and Functional Outcome. / Die winkelstabile Plattenosteosynthese der Patellafraktur ­ Komplikationsanalyse und funktionelles Ergebnis.

BACKGROUND: Tension band wiring is the standard procedure for patellar fractures, but is associated with a high rate of implant related complications and implant failure. Tension band wiring may fail, especially with multifragmentary and comminuted fractures. Plate fixation of complex patellar fractures seems to be superior to wiring, both clinically and biomechanically. The aim of this study was to evaluate complications after locking plate fixation in patellar fractures two years after surgery and to access the functional outcome. MATERIAL AND METHODS: As part of a prospective case series, all patients who had received locking plate fixation of a patellar fracture between April 2013 and May 2018 were clinically examined two years postoperatively and potential complications were evaluated. RESULTS: A total of 38 patients aged 19 - 87 years were included. Complications occurred in a total of five patients (13%), including one reactive prepatellar bursitis, one chronic infection and loss of reduction due to a dislocated pole fragment in three cases. The average active range of motion of the affected knee joint two years postoperatively was 133°. The Tegner activity scale score reached 3 points, the Lysholm score 95 points and the Kujala score 95 points. CONCLUSION: With an overall relatively low complication rate and good clinical outcome, dislocated distal pole fragments are a common complication after plate fixation of patellar fractures. If preoperative diagnostic testing shows a pole fragment, a modified hook-plate can be used, with the possibility of fixing the pole fragment.