What is the treatment for a dislocated patella?

Treatment for Dislocated Patella

For first-time patellar dislocation, nonoperative treatment with functional bracing for 4-6 weeks is the recommended approach, reserving surgery only for osteochondral fractures or recurrent instability. 1

Initial Management and Reduction

Immediate Reduction

• Patellar reduction can be performed in the prehospital setting by EMS providers with a 92% success rate and significant pain relief (median pain score reduction from 10 to 2), with no reported complications 2
• Early reduction provides substantial pain relief and should be attempted promptly 2

Initial Diagnostic Imaging

• Obtain anteroposterior and lateral radiographs as the first-line imaging modality 3, 1
• Add a patellofemoral (axial) view to evaluate for patellar fractures and degree of subluxation or dislocation 3, 1
• Weight-bearing axial radiographs best demonstrate patellofemoral kinematics and the degree of patellar tilt 1
• MRI should be obtained after initial radiographs to identify osteochondral fractures, bone marrow contusions, and ligamentous injuries that would change management 1

Nonoperative Treatment (First-Line for Primary Dislocation)

Functional Support Protocol

• Use an ankle-style functional brace for 4-6 weeks rather than rigid immobilization 1
• Braces demonstrate the greatest treatment effects compared to other types of functional support 1
• If immobilization is necessary for severe pain or edema, limit it to a maximum of 10 days, then transition to functional support 1

Evidence Supporting Conservative Management

• Approximately 60-70% of patients respond well to nonoperative treatment 1
• Long-term studies show no significant difference between surgical and conservative treatment after first-time dislocation in children, adolescents, and adults 4, 5
• At 14-year follow-up, 75% of nonoperatively treated patients had good or excellent subjective outcomes compared to 66% of surgically treated patients 6
• Routine surgical repair of medial structures does not improve long-term outcomes despite high recurrence rates 6

Surgical Indications (Selective)

Primary Indications

• Osteochondral fractures identified on imaging 1, 5
• Significant concomitant injuries requiring surgical intervention 7, 5
• Large intra-articular fragments (>15 mm) 6

Secondary Indications

• Recurrent patellar instability after failed conservative management 7, 5
• Professional athletes may benefit from earlier surgical intervention to ensure quicker return to play 1

Risk Assessment for Recurrence

High-Risk Factors to Identify

• Positive family history of patellar instability (strongest predictor for recurrence) 6
• Patella alta 5
• Increased tibial tuberosity-trochlear groove (TT-TG) distance 5
• Trochlear dysplasia 5
• Torsional abnormalities 5

Expected Recurrence Rates

• Recurrent dislocation occurs in up to 40% of patients after first-time dislocation 4
• In long-term studies, recurrence rates were 71% for nonoperative treatment and 67% for operative treatment, showing no significant difference 6
• Most first redislocations occur within two years of the primary injury (52% of recurrent cases) 6

Common Pitfalls to Avoid

• Avoid routine surgical repair for first-time dislocations without osteochondral fractures, as surgery carries risks of complications, knee stiffness, and impaired mobility without improving outcomes 1, 6
• Do not skip MRI evaluation, as it is critical for detecting osteochondral fractures that would change management from conservative to surgical 1
• Avoid prolonged rigid immobilization beyond 10 days, as functional bracing produces superior outcomes 1
• Do not assume surgery prevents recurrence—operative treatment does not significantly reduce recurrence rates compared to conservative management 4, 6