Irreducible Knee Dislocation with Vastus Medialis Muscle Interposition

Abstract

Knee dislocation is one of the rare orthopedic emergencies that require special management with an annual incidence rate of less than 0.02%. Knee dislocations are classified by Kennedy, according to the direction of tibial dislocation in relation to the femur, as anteromedial, posteromedial, anterolateral, and posterolateral. Operative intervention and multi-ligament reconstruction are usually required in knee dislocation. Interposition of the vastus medialis inside the joint of a dislocated knee is an uncommon scenario where reduction becomes impossible. In this report, we present a case of irreducible knee dislocation with vastus medialis muscle interposition. Before reduction, we performed arthroscopy of the knee and removal of the interposed muscle to prevent extravasation of the fluid by sealing the torn capsular area.

Irreducible Posterolateral Knee Dislocation

“…A n IKD is an extremely rare injury. Only 4 reported cases with the additional incarceration of the VMO muscle, along with the medial retinaculum in the ICN, are currently described in the literature [5][6][7][8] . The classic dimple sign, or pucker sign, was reported to be present in 83% of the cases and described as a pathogno-monic sign for IKD diagnosis 3,9 .…”

“…It can also accommodate a possible total knee replacement on the future 8 . Meanwhile, a straight medial incision directly approaches the medial retinaculum, and repair/ reconstruct of the medial side structures may be facilitated 5 .…”