Surgery to fix kneecap bone fractures after patellar luxation

Abstract

IntroductionIn this report of three clinical cases, we describe the diagnosis and surgical management of trochlear ridge fractures occurring during or after medial patellar luxation (MPL) correction in small-breed dogs.Case reportThree small-breed dogs diagnosed with grade 3 MPL sustained trochlear ridge fractures associated with MPL surgery. In one dog, an iatrogenic fracture occurred intraoperatively during block recession; in contrast, postoperative fractures developed in two dogs approximately 2 months postoperatively after block recession. At follow-up, recurrent patellar luxation was identified, but no trochlear ridge fracture was noted. Each case involved a fracture of the lateral or medial trochlear ridge with preservation of periosteal continuity. Stabilization was performed by placing screws for subfragmentary buttress support beneath the displaced bone fragment to restore ridge integrity. Implant-related complication occurred only in one case that required implant removal due to screw prominence. No dog demonstrated lameness, and resolution of patellar luxation was noted in all dogs with functional recovery maintained for a minimum of 12 months postoperatively.ConclusionScrew fixation was used to buttress the displaced trochlear ridge fragment in these cases where periosteal continuity was preserved. Fragment positioning was maintained during the follow-up period in all dogs. This report is descriptive in nature and does not aim to validate biomechanical efficacy or recommend this fixation method over existing techniques.