Functional Outcome of Revision Osteosynthesis after failed surgical treatment of patellar fractures

Abstract

Aims and Objectives: Patellar fractures account for approximately 1% of all skeletal fractures. They are rare, but due to the crucial function of the patella in the extensor mechanism of the knee they can lead to a serious impairment. New data are revealing functional impairment remains common even with improved surgical techniques. The aim of this study is to asses the functional outcome of patients after revision surgery in case of secondary fracture dislocation or remaining articular incongruity. Materials and Methods: The study was designed as a retrospective observatory study. We included all patients who underwent a revision surgery because of a remaining articular incongruity or a secondary fracture dislocation or re-fracture from January 2010 until december 2016. Results: Sixteen patients of mean age 51,8 years were included in the study with a mean follow-up period of 28,8 months. Fifteen patients had AO type C fractures, within ten a C3 fracture. Thirteen were initially treated with tension band wiring via k-wires or cannulated screws. The reason for a revision surgery were 5 times a remaining articular incongruity, 11 times a secondary fracture dislocation or re-fracture. We analysed pain, satisfaction, range of motion, Böstman-Score, Tegner-Score and KOOS and could extract follow-up data from 15 of the patients. All fractures healed, no articular incongruity remained. Mean pain measured with the visual analogue scale (0-10) was at rest 0,57 (range 0-3,5), on exertion 2,79 (range 0-8). The measurement of the range of motion compared with the opposite knee showed a complete extension. Mean Flexion was 120°, in the opposite knee 136° (p = 0,05). Mean postoperative Böstman-Score and Tegner-Score were 25,11 (good, max. 30) and 78,67 (moderate, max. 100). KOOS: symptoms 66,8 points, pain 77,55 points, ADL 75,67 points and qualitiy of life 56,25 points. Conclusion: Early revision surgery in case of secondary fracture dislocation, re-fracture or remaining articular incongruity leads to statisfactory functional outcomes. Furthermore in case of complexe fractures the tension band wiring technique shouldn’t be the first choice, alternatives like the plate osteosynthesis should be considered.