How should a 12-year-old female with an isolated medial patellofemoral ligament tear from basketball be managed?

Management of Medial Patellofemoral Ligament Tear in a 12-Year-Old Female

Initial conservative management with early mobilization, quadriceps strengthening, and combined hip-knee exercise therapy is the recommended first-line treatment for this isolated MPFL tear, with surgical MPFL reconstruction reserved for recurrent instability or high-risk anatomical features.

Initial Conservative Approach

For a first-time traumatic MPFL tear in a skeletally immature patient, begin with non-operative management 1, 2. This involves:

• Short immobilization period (typically 1-2 weeks) followed by early passive range of motion
• Quadriceps strengthening with emphasis on vastus medialis obliquus activation
• Combined hip and knee exercise therapy - this combination is superior to knee exercises alone for reducing pain and improving function 3
• Education about the injury and rehabilitation process 4

The conservative approach is particularly appropriate for true traumatic dislocations without cartilaginous injury 2.

Critical Assessment for Surgical Decision-Making

You must evaluate specific risk factors that predict recurrent dislocation, as these determine whether conservative management will fail:

High-Risk Anatomical Features to Identify:

• Skeletal abnormalities (trochlear dysplasia, patella alta)
• Increased Q-angle
• Generalized ligamentous laxity
• Family history of patellar instability
• TT-TG distance (tibial tuberosity-trochlear groove measurement via CT)
• Osteochondral fracture fragments on imaging 1, 2, 5

Imaging Workup Required:

• Plain radiographs of the knee
• MRI to assess MPFL injury pattern and identify osteochondral injuries
• CT scan for TT-TG measurement if surgical planning needed 5, 6

When to Proceed with Surgery

Surgical intervention is indicated when:

1. Conservative management fails after adequate trial (typically 3-6 months)
2. Recurrent dislocations occur (redislocation rate approaches 80% in atraumatic cases with skeletal deformities) 2
3. High-risk anatomical features are present at initial presentation
4. Osteochondral fracture is identified requiring fixation 1

Surgical Treatment: MPFL Reconstruction

For skeletally immature patients like this 12-year-old, physeal-sparing MPFL reconstruction is the treatment of choice 1, 7, 6.

Key Technical Considerations:

• Physeal-sparing technique is mandatory - the MPFL origin is distal to the distal femoral physis, allowing safe reconstruction 7
• MPFL reconstruction can be performed even with open growth plates 2
• The MPFL and vastus medialis obliquus are the primary restraints to lateral patellar translation 1
• Isolated MPFL reconstruction is effective when normal anatomy and kinematics are present 8

Additional Procedures in Skeletally Immature Patients:

• Patella alta: Address with patellar tendon shortening 6
• Increased TT-TG distance: Consider Grammont medialization technique 6
• Valgus knee: Manage with growth modulation 6

Critical Pitfall: Avoid bony procedures like trochleoplasty or tibial tubercle osteotomies until after physeal closure 2, 6. These should be deferred until skeletal maturity.

Common Pitfalls to Avoid

1. Assuming all first-time dislocations do well conservatively - up to 80% of atraumatic dislocations with skeletal deformities will redislocate 2
2. Performing physeal-violating procedures in skeletally immature patients
3. Ignoring underlying anatomical risk factors that predict failure of isolated MPFL reconstruction
4. Delaying surgical intervention in patients with clear high-risk features and recurrent instability

Rehabilitation After MPFL Reconstruction

Post-operative management should emphasize:

• Early passive motion to prevent stiffness
• Progressive quadriceps strengthening
• Combined hip and knee exercises as per patellofemoral pain guidelines 3
• Gradual return to basketball activities based on functional milestones

The evidence strongly supports that exercise therapy targeting both hip and knee musculature reduces pain and improves function across all time points 3, making this the cornerstone of both conservative and post-operative rehabilitation.