chapter 9:Patellar Subluxation


A positive diagnosis of recurrent subluxation can be somewhat difficult as is always the case at the boundary between normal and abnormal. The diagnosis incorporates the history, the careful physical examination of both knees, particularly the course of the patella in flexion and extension, and the evaluation of radiographs. Computerized tomography (CT), as described in Chapter 4, is particularly helpful in differentiating subluxation from tilt. When a young patient presents with complaints of discomfort, swelling, insecurity, and a poorly defined functional abnormality, vis‑á‑vis the knee, whether trauma be part of this history or not, the clinician should think systematically about whether the patient manifests predominantly a pattern of subluxation‑instability, tilt‑compression, or a combination of both.

The patient with hypermobility of the patella and a feeling of insecurity or instability may be more likely to have some degree of patellar subluxation, whereas the patient with a tight, laterally fixed patella and lateral retinacular tenderness is more likely to have a problem with tilting of the patella.




Inside Chapter 9: