What is the treatment for a superior dislocation of the patella?

Treatment of Superior Patellar Dislocation

Superior patellar dislocation should be treated with immediate closed reduction under analgesia, followed by knee immobilization for 3 weeks, with arthroscopic removal of interlocking osteophytes if recurrence occurs. 1, 2

Immediate Management

Closed Reduction Technique

• Perform closed reduction immediately using intramuscular analgesia to provide pain relief and restore knee function 1
• The reduction can be safely performed in the prehospital setting by EMS providers, with a 92.2% success rate and no reported complications 3
• Closed reduction typically reduces pain scores from 10/10 to 2/10 immediately 3
• The procedure provides significant pain relief and allows restoration of knee range of motion 1

Post-Reduction Immobilization

• Immobilize the knee for 3 weeks in a posterior long knee brace following successful reduction 1
• This immobilization period allows soft tissue healing and prevents immediate re-dislocation 1

Diagnostic Confirmation

Clinical Examination Findings

• The superior pole of the patella protrudes anteriorly and is markedly tender on palpation 1
• The knee is locked in extension and cannot be flexed 1, 2
• The patellar tendon remains intact 1

Radiographic Features

• Obtain standard knee radiographs (anteroposterior and lateral views) to confirm the diagnosis 4, 1
• The pathognomonic radiographic finding is the superior part of the patella tilted away from the femur, caused by pull of the patellar tendon with simultaneous relaxation of the quadriceps tendon 2
• Look for interlocking patellofemoral osteophytes, which are the causative mechanism in degenerative knees 2

Management of Recurrent Cases

Surgical Intervention

• If recurrence occurs within days to weeks after initial reduction, perform arthroscopy to remove the causative interlocking osteophytes 2
• Arthroscopic removal of osteophytes prevents further episodes of superior dislocation 2
• In the reported case with arthroscopic osteophyte removal, no recurrence was observed at 12-month follow-up 2

Mechanism and Pathophysiology

Understanding the Injury

• Superior dislocation occurs from unloaded hyperextension, often from trivial trauma such as bumping the knee on furniture or attempting to kneel 1, 2
• The mechanism involves interlocking of patellofemoral osteophytes in degenerative knees, causing the knee to lock in extension 2
• This is distinctly different from the more common lateral patellar dislocation 2, 5

Key Clinical Pitfalls

• Do not confuse superior dislocation with lateral patellar dislocation—the mechanisms, presentations, and treatments differ significantly 2
• Do not delay reduction—immediate closed reduction provides substantial pain relief and prevents complications 1, 3
• Do not order unnecessary advanced imaging initially—the diagnosis can be made with certainty on physical examination and plain radiographs alone 2
• Recognize that recurrence indicates underlying mechanical pathology (osteophytes) requiring surgical removal rather than failed conservative management 2