Treatment of patellofemoral instability in Down's syndrome.

In a retrospective review, 16 patients with Down's syndrome with the chief complaint of patellofemoral joint dislocations or subluxations were studied. Twenty-six dislocatable or dislocated patellae were seen in these 16 patients. The degree of patellofemoral instability was not correlated with either the ambulatory status or the form of treatment (operative/nonoperative). An increasing degree of patellofemoral instability was correlated strongly with the presence of deformities. Nonoperative treatment either maintained or improved the ambulatory status in 67% of these knees with either fair or good ambulation, whereas 80% of the knees with poor ambulation did not improve. Operative treatment resulted in good ambulatory ability in 86% of the knees with fair or poor preoperative ambulatory status, but did not effectively correct deformities that subsequently resulted in degenerative arthritis.