Neglected Locked Patellar Dislocation in an Adult Female: Report of a Rare Case

INTRODUCTION: Dislocation of patella is a very common injury which usually reduces spontaneously or can be reduced easily using gentle manipulation. Irreducible patellar dislocations are rare and usually result due to either rotation of patella along the horizontal or vertical axis or due to bony impaction. Neglected locked patellar dislocations are extremely rare injuries presenting additional challenges. CASE REPORT: We are reporting a case of a 24-year female who presented to us 4 months after suffering a knee injury for which she received native treatment initially. On presentation, patient was able to walk with a limp and some discomfort but was unable to squat or sit cross-legged. Clinical examination revealed a patellar dislocation which was irreducible. On open reduction, the patella was found to be locked in the lateral gutter with rotation along its vertical axis and with an osteochondral fracture of its medial margin. There were a lot of fibrotic adhesions which required extensive release, following which the patella could be derotated and reduced into the trochlear groove. The medial retinaculum was repaired using transosseous sutures. Postoperatively, the patient developed wound edge necrosis which was managed with debridement and secondary suturing. At 1-year follow-up patient had almost full knee range of motion without any signs of patellar pain or instability and was able to squat and sit cross-legged. CONCLUSION: Unlike acute irreducible patellar dislocations which can be managed easily with open reduction, a neglected dislocation necessitates wider surgical exposure and a lot of soft tissue releases, which may jeopardize vascularity of the soft tissues leading to wound healing problems. Release of all adhesions while taking care to prevent further chondral injury, adequate lateral retinacular release, derotation of patella to relocate it into trochlear groove, and meticulous medial retinacular repair is essential for a successful outcome.