What is the management plan for patella dislocation?

Management of Patellar Dislocation

The management of patellar dislocation should begin with immobilization using a posterior splint for 3-4 weeks, as this provides the lowest redislocation rates while minimizing knee joint movement restrictions. 1

Initial Assessment and Diagnosis

• Radiographic evaluation: Obtain anteroposterior and lateral knee radiographs to rule out fractures and assess for osteochondral fragments 2
• MRI evaluation: Consider MRI without contrast if there is suspicion of osteochondral injury or substantial disruption of medial patellar stabilizers 2, 3
• Clinical assessment: Evaluate for:
  • Joint effusion
  • Focal tenderness along medial patellofemoral ligament
  • Inability to bear weight
  • Apprehension with lateral patellar movement

Acute Management

1. Reduction: If the patella remains dislocated:

   • Perform gentle reduction by extending the knee while applying gentle medial pressure on the lateral aspect of the patella
   • Success rates of prehospital reduction protocols are high (92.2%) with significant pain reduction and minimal complications 4

2. Immobilization options:

   • Posterior splint: Provides lowest redislocation rate (0.08 per follow-up year) with minimal knee joint movement restriction 1
   • Cylinder cast: Effective for preventing redislocation (0.12 per follow-up year) but causes more knee joint movement restriction 1
   • Knee brace: Associated with higher redislocation rates (0.29 per follow-up year) 1

3. Duration of immobilization:

   • 3-4 weeks is recommended by most surgeons (52%) 5
   • Range of motion should be limited to full extension to 30° during first 15 days, progressing to 60° for an additional 15 days 5

Weight-bearing Recommendations

• 49% of surgeons recommend weight-bearing as tolerated during conservative treatment 5
• 34% recommend partial weight-bearing (30-60% of body weight) 5
• 17% advise against weight-bearing during initial recovery 5

Rehabilitation Protocol

1. Early phase (0-4 weeks):

   • Immobilization with posterior splint
   • Quadriceps isometric exercises
   • Gentle range of motion exercises as tolerated within brace limitations

2. Intermediate phase (4-8 weeks):

   • Progressive range of motion exercises
   • Strengthening of quadriceps and hip abductors
   • Proprioceptive training

3. Advanced phase (8-12 weeks):

   • Sport-specific exercises
   • Return to activity when full range of motion and strength are restored

Indications for Surgical Management

Initial surgical management should be considered in the following circumstances 3:

• Presence of osteochondral fracture
• Substantial disruption of medial patellar stabilizers
• Laterally subluxated patella with normal alignment of contralateral knee
• Second dislocation
• Failure to improve with appropriate rehabilitation
• Young patients (<35 years) participating in contact sports 5
• Significant anatomic risk factors:
  • TT-TG distance >15-20mm
  • Trochlear dysplasia (types C and D)
  • Patella alta

Common Pitfalls and Caveats

• Missed diagnosis: Always obtain radiographs to rule out fractures or osteochondral injuries
• Inadequate immobilization: Using removable braces without proper education may lead to higher redislocation rates
• Neglecting rehabilitation: Failure to address quadriceps weakness and proprioceptive deficits increases recurrence risk
• Delayed surgical referral: Patients with specific risk factors for recurrence should be identified early
• Overlooking predisposing factors: Anatomic abnormalities should be identified and addressed to prevent recurrence

Long-term Outcomes

• Recurrence rates after conservative treatment range from 15-44%
• Risk factors for recurrence include:
  • Young age
  • Female gender
  • Anatomic abnormalities (trochlear dysplasia, patella alta)
  • Participation in high-risk sports

While the evidence for optimal management of first-time patellar dislocation remains limited, current best evidence suggests that posterior splinting for 3-4 weeks provides the best balance between preventing redislocation and minimizing knee joint movement restrictions 1.