摘要
BACKGROUND Inferior intra-articular patella dislocation is rare and comprises horizontal(type 1)and the more common vertical(type 2)dislocations in young and elderly patients respectively.In this case report,we describe a case of an elderly patient who pre sented with a type 2 dislocation after a fall.The mechanisms of inferior patella dislocation,their classification,key imaging features and treatment options are discussed.CASE SUMMARY A 75-year-old woman presented with a right knee fixed flexion deformity after a fall.Preoperative imaging confirmed a vertical intra-articular patella dislocation with a femoral trochlear osteochondral defect and lax though grossly intact patella tendon.Closed reduction was performed under general anaesthesia.Knee arthroscopy confirmed the presence of a femoral trochlear osteochondral defect whose edges were subsequently smoothed and there was debridement of scant debris with thorough irrigation of the joint.Postoperative imaging demonstrated anatomical alignment,however,there was a new nondisplaced medial femoral trochlear.The patient however was able to mobilise well in a range of motion brace set at 0-30 degrees and was discharged 1-day post operatively.CONCLUSION Inferior patella dislocation is rare and this article highlights its types and imaging features which determine the most appropriate management.
