الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
A higher incidence of patellar dislocations occur in females ages 10 to 17 years of age and the athletically active, with less incidence over age 30. Lateral dislocations are very common. Medially dislocations are rare. Patellar stability is dependent upon two components: bony and soft tissue structures. The medial patellofemoral ligament (MPFL) provides 50-80% of total restraining force medially. Although several predisposing factors may exist, patellar dislocation is most commonly associated with familial ligamentous laxity. Patellofemoral dislocations can occur from indirect, twisting or rapid change of direction with the foot planted or direct trauma to patella. The dislocation usually reduces spontaneously. Once the normal relationship of the patellofemoral joint is restored, patients may begin their rehabilitation. If the dislocation recurs after a trial of rehabilitation, operative intervention is considered. Operative treatment is recommended in the presence of anatomical abnormalities or osteochondral fractures. Many different procedures are performed to correct patellar instability. Understanding the anatomy and biomechanics of the patellofemoral joint will guide future testing and treatment methods. Recent anatomic and biomechanical studies have demonstrated that the MPFL and the VMO are the primary restraints to lateral translation and ultimately dislocation of the patella. Management should therefore be directed both at correcting anatomic abnormalities when indicated and at reconstruction of medial restraints to patellar tracking.