Diagnosis and treatment of patellofemoral joint instability

Background: Patellofemoral instability, by definition, is a condition where the patella bone pathologically disarticulates out from the patellofemoral joint, either through subluxation or complete dislocation. The overall incidence of patellofemoral instability ranges between 5.8 and 29 per 100,000. Over time, patients with patellar instability can have debilitating pain, limitations in basic function, and long-term arthritis.Current Concepts: Risk factors for patellofemoral instability include trochlear dysplasia, patella alta, increased tibial tubercle-to-trochlear groove distance, abnormal patella lateral tilt, and coronal and torsional malalignment. The proper treatment is often debatable. Conservative treatment is suitable for acute dislocation but has a high failure rate for chronic instability, which usually necessitates surgical treatment. Today’s common surgical treatments focus on fixing anatomical defects, relieving symptoms of instability, and allowing patients to return to a suitable level of activity.Discussion and Conclusion: In this review, we summarize the relevant pathophysiology, categorization, clinical features, physical examination, imaging, and treatment options for patellofemoral instability.