What is the treatment for patella dislocation?

Treatment of Patellar Dislocation

The initial treatment for acute patellar dislocation should be closed reduction followed by a period of immobilization with a neoprene nonhinged knee brace rather than a motion-restricting brace, as this approach provides better functional outcomes while maintaining similar redislocation rates. 1

Initial Assessment and Management

Imaging

• Radiographs are the first-line imaging modality for suspected patellar dislocation
  • Standard views should include: anteroposterior (AP), lateral, and patellofemoral (sunrise/Merchant) views 2
  • Weight-bearing axial views are recommended to better assess patellofemoral kinematics 2
• CT scans are indicated when:
  • Fracture patterns are complex or radiographically occult
  • Better characterization is needed for preoperative planning
  • Assessment of articular surface involvement is required 2
• MRI is superior for detecting:
  • Concomitant soft tissue injuries
  • Osteochondral fractures
  • Bone marrow abnormalities 2

Acute Management

1. Closed reduction should be performed promptly to relieve pain and prevent further damage

   • Can be successfully performed in the prehospital setting with 92.2% success rate and significant pain reduction (median pain score reduction from 10 to 2) 3
   • No reported complications with properly performed reductions 3

2. Post-reduction immobilization:

   • A neoprene nonhinged knee brace is preferable to a motion-restricting brace
   • Patients with nonhinged braces demonstrate:
     • Better knee range of motion at 4 weeks (115° vs 90°) and 3 months (133° vs 125°)
     • Less quadriceps muscle atrophy
     • Better functional outcomes at 6 months (higher Kujala scores) 1
   • Recommended duration: 4 weeks of continuous brace use 1

Treatment Decision Algorithm

Primary (First-time) Dislocation

• Conservative management is indicated for most first-time dislocations 4, 5
  • Immobilization with neoprene nonhinged brace for 4 weeks
  • Physical therapy focusing on quadriceps strengthening
  • Gradual return to activities

Indications for Surgical Management

• Presence of relevant concomitant injuries:
  • Osteochondral fractures
  • Large chondral fragments
• Patients with high risk of recurrence based on anatomical factors:
  • Patella alta
  • Increased Tibial Tuberosity-Trochlear Groove (TT-TG) distance
  • Trochlear dysplasia
  • Torsional abnormalities 5

Recurrent Dislocations

• Surgical intervention is typically indicated for recurrent dislocations 5
• Surgical options include:
  • Medial Patellofemoral Ligament (MPFL) reconstruction
  • Tibial tuberosity transfer procedures
  • Trochleoplasty in cases of severe trochlear dysplasia

Outcomes and Prognosis

• Recurrent dislocation occurs in up to 40% of people after first-time dislocation 4
• Based on current evidence, surgical treatment may reduce recurrent dislocations compared to non-surgical management (157 fewer recurrences per 1000 patients) 4
• However, surgery may increase the risk of adverse events 4

Common Pitfalls to Avoid

• Failing to obtain proper imaging to rule out associated fractures or osteochondral injuries
• Prolonged immobilization leading to quadriceps atrophy and decreased range of motion
• Using motion-restricting braces unnecessarily, which can lead to worse functional outcomes
• Neglecting to assess anatomical risk factors that may predispose to recurrent dislocations
• Delaying reduction, which increases pain and potential for cartilage damage

Special Considerations

• Superior patellar dislocation is a rare variant that presents with painful locking of the knee and requires prompt closed reduction 6
• In children with 22q11.2 deletion syndrome, patellar dislocation may occur more frequently and require special attention 7

Remember that while conservative management is appropriate for most first-time dislocations, a thorough analysis of anatomical risk factors should be performed early to guide proper patient counseling and identify those who might benefit from surgical intervention.