Traumatic problems of the patella

This article will outline the clinical presentation and management of patellar instability and fracture. Patellar instability is a generic term that describes anything from symptomatic apprehension to patellar subluxation and through to patellar dislocation. It can result from osseous abnormalities such as patella alta or patellofemoral dysplasia or it can arise secondary to soft tissue abnormalities such as a torn medial patellofemoral ligament. Failing conservative management, surgical treatment is directed to the underlying cause(s) of the instability, and can include medial patellofemoral ligament reconstruction or a bony realignment procedure.Patellar fracture is a common injury caused by excessive tension through the extensor mechanism or a direct blow. Such injury can lead to stiffness, extension weakness and patellofemoral arthritis. Non-surgical management is indicated for non-displaced fractures with an intact extensor mechanism. Surgical fixation is recommended for fractures that either disrupt the extensor mechanism or that demonstrate over 2–3 mm of step-off and/or over 1–4 mm of displacement. Anatomic reduction and fixation with a tension-band technique is associated with the best outcomes; however, symptomatic hardware is a frequent complication.