Patella instability is an important diagnosis in young active individuals with a history of acute knee injury. In high-risk individuals, instability can become chronic and, if left untreated, increase risk of secondary cartilage defects and early onset osteoarthritis.
The presentation of patella instability can range from sudden acute debilitating dislocation requiring urgent reduction to more minor episodes of subluxation. Both males and females can suffer from patella instability but it is more common in females, with many suffering their first dislocation as a teenager. In the general population, patella dislocations occur at a rate of 5.8 per 100,000; female athletes aged 10 to 17 years have the highest risk, with a reported rate of 33 per 100,000.1