Non-traumatic dislocation (Cam Jump) in a revision knee: a case report

Dislocation after total knee arthroplasty is a difficult problem and is even more challenging if it occurs following revision. We report the case of a 82 year old male presenting after a frank posterior dislocation (Cam Jump) in a posterior stabilized revision knee arthroplasty without trauma. Flexion space instability with extensor insufficiency was presumed to be the cause of the dislocation without significant trauma. The possibility of worsening collateral stability with high flexion ranges following knee replacement is also explored.