Lateral patellar dislocation with vertical axis rotation of 90°

Neglected locked vertical patellar dislocation

“…The patella rotates on its vertical axis and gets wedged within intercondylar groove or outer surface of lateral femoral condyle 12. Laxity of the ligaments allowing for greater mobility of the patella was thought to be a predisposing factor in adolescent patients 13. Colville suggested that a valgus strain on the knee could cause the patella to rotate on its vertical axis and the continued pull of the quadriceps would then hold the patella on its edge 1014.…”

“…Some authors have reported success with closed reduction under conscious sedation 15. In a recent review, open reduction was recommended to reduce the risk of chondral damage by repeated attempts at manipulation and to repair or remove any osteochondral fractures 13. The malrotated patella results in increased tension within the extensor mechanism, which in turn locks the patella between the femoral condyles, making manipulation difficult.…”

Arthroscopic reduction of a locked patellar dislocation: a new less invasive technique

“…A case of irreducible patella is mostly caused by a direct medial blow with the knee in extension or slight flexion [1, 4, 6, 9–11, 13, 14, 16, 22, 25]. It can also occur without direct trauma [2, 15, 17, 18, 21] and in patients with previous history of patellar dislocation as described by Higgins and Khalfaoui and Devgan et al [5, 12].…”

“…The reduction methods previously described for irreducible patella cases are either closed [1, 10, 13, 18, 22] by applying lateral pressure to the medial patellar surface while performing gentle knee hyperextension or by arthrotomy (mini-open approach) [2, 4–7, 9, 11, 12, 14–17, 21, 25] as opposed to arthroscopic as in the current case.…”

“…Early passive ROMGorczya [9]200013MYesLong axis rotationNoOpenMedial repairNoElMaraghy [6]200230FYesLong axis rotationNoOpenMedial repair5 weeks full weight bearing allowedPhaltankar [21]200266MNoLateral femoral impactionMRIOpenTotal knee arthroplastyNoSherman [22]200428MYesLong axis rotationNoClosedNo4 weeksAbdelhalim [1]20078MYesLong axis internal rotation–Closed–4 weeksFeibel [7]200766FYesLateral femoral impactionCTOpenNoNo early mobilizationHuang [13]200812MYesLong axis rotationNoClosedNo3 weeksMichels [17]200816FNo…”