What is the recommended management for a 16-year-old with a second patellar dislocation, moderate bone‑marrow edema of the lateral femoral condyle, mild patella alta, and no trochlear dysplasia or ligamentous injury?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: September 30, 2026 • View editorial policy

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question

Management of Second Patellar Dislocation in a 16-Year-Old

For this 16-year-old with a second patellar dislocation, mild patella alta, and no trochlear dysplasia or ligamentous injury, I recommend surgical intervention with medial patellofemoral ligament (MPFL) reconstruction as the primary treatment, combined with addressing the patella alta through tibial tubercle distalization if skeletal maturity is confirmed.

Rationale for Surgical Intervention

After a second dislocation, the risk of recurrent instability is substantial, and conservative management has demonstrated high failure rates 1, 2. MPFL reconstruction is the most important treatment across all age groups for recurrent patellar instability 1. The MPFL ruptures in almost all patellar dislocations, making its reconstruction the primary procedure currently selected by most surgeons as first-line treatment for recurrent dislocation 2.

Key Decision Points:

1. Why Surgery Over Conservative Treatment:

  • First dislocations are typically managed conservatively, but surgical strategies after a second dislocation depend on injury pattern and severity of anatomic risk factors 3
  • Conservative treatment after recurrent dislocations has high recurrence rates and frequently leaves knee joint dysfunction 4
  • The presence of patella alta (even mild) represents an anatomical predisposing factor that increases redislocation risk 5

2. Addressing the Patella Alta:

  • At age 16, assess skeletal maturity via radiographs (hand/wrist or knee physes)
  • If physes are closed: Perform tibial tubercle osteotomy with distalization and medialization 1
  • If physes remain open: Consider tendon shortening procedures or the Grammont technique for medialization 1
  • The mild patella alta must be addressed because it represents a measurable risk factor for recurrent instability

3. Favorable Prognostic Factors in This Case:

  • No trochlear dysplasia - This is critically important. Trochlear dysplasia is one of the most relevant predisposing variants 3, and its absence means isolated MPFL reconstruction has higher success rates
  • No ligamentous injury - The lateral structures are intact, simplifying the reconstruction
  • Moderate bone marrow edema only - No osteochondral fracture requiring immediate surgical fixation

Surgical Algorithm

Step 1: Confirm skeletal maturity

  • Obtain hand/wrist radiographs or assess distal femoral/proximal tibial physes
  • This determines whether bony procedures can be safely performed

Step 2: Primary procedure - MPFL reconstruction

  • Anatomic reconstruction of the MPFL is more effective than non-anatomic techniques in preventing recurrent dislocation 2
  • This addresses the ruptured medial restraint from both dislocation episodes

Step 3: Address patella alta

  • If skeletally mature: Add tibial tubercle distalization (moving insertion point distally to lower patellar height)
  • If skeletally immature: Perform soft tissue procedures such as patellar tendon shortening or Grammont medialization technique to avoid premature physeal closure 1

Step 4: Postoperative rehabilitation

  • Early range of motion within protected ranges
  • Progressive quadriceps strengthening (critical for long-term stability)
  • Gradual return to activity over 4-6 months

Common Pitfalls to Avoid

  1. Underestimating the significance of a second dislocation - The recurrence risk escalates dramatically after the second event, and anatomical factors (patella alta) will not resolve spontaneously

  2. Performing isolated MPFL reconstruction without addressing patella alta - While the absence of trochlear dysplasia is favorable, the patella alta still requires correction for optimal stability

  3. Delaying surgery in skeletally immature patients - Soft tissue procedures can be performed safely and "buy time" until definitive bony procedures are possible at skeletal maturity 5

  4. Assuming conservative treatment is adequate - After a second dislocation with anatomical risk factors present, conservative management has unacceptably high failure rates 4

Important Caveats

  • Athletic participation: Return to previous activity levels, especially competitive sports, may be limited and is difficult to predict after patellar dislocation 2

  • Timing considerations: Surgery should be performed after acute bone marrow edema resolves (typically 6-8 weeks), but not delayed excessively to prevent further episodes

  • Skeletal immaturity modifications: If physes are open, avoid tibial tubercle osteotomy and trochleoplasty to prevent growth disturbance and limb deformity 2, 5

The combination of MPFL reconstruction with correction of patella alta provides the best chance of preventing future dislocations while the absence of trochlear dysplasia significantly improves the prognosis compared to patients with multiple anatomical risk factors 1, 3.

References

3
Research

[MRI after patellar dislocation: assessment of risk factors and injury to the joint].

RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin, 2013

4
Research

[Advances on the treatment of the first-time patellar dislocation in children and adolescents].

Zhongguo gu shang = China journal of orthopaedics and traumatology, 2026

Related Questions

What is the appropriate treatment for a possible lateral patellar subluxation in a 16-year-old whose alignment has improved over the past week?
In a 14-year-old with recurrent patellar dislocation, is using a DonJoy Playmaker or DryTech ROMSTOP brace locked at 0‑30° acceptable while awaiting MRI?
What is the recommended treatment for a patellar dislocation?
How should chronic bilateral patellar dislocation be evaluated and managed?
In a patient with an acute knee injury and suspected medial patellar fragment after a recent patellar dislocation, unable to perform a straight‑leg raise and showing signs of patellar instability, should a CT scan be expedited?
How rare is mixed connective tissue disease in a 30‑year‑old Black male with a speckled antinuclear antibody pattern and elevated anti‑RNP antibodies, given otherwise normal complete blood count, comprehensive metabolic panel, liver enzymes, and renal function?
Is a 6-year-old child eligible to receive the Kinrix (diphtheria, tetanus, acellular pertussis, inactivated polio) vaccine as a booster dose?
What is the recommended management for functional constipation in a toddler, including fluid intake, dietary fiber, activity, toileting routine, and polyethylene glycol (PEG 3350) dosing?
In a stable 27-year-old woman with new-onset right-sided facial tingling, intermittent facial fasciculations, negative clinical exams, no neurological deficits, and no history of cold sores or vision changes, how is Bell's palsy confirmed?
In an adult patient with stable opioid use disorder on a steady methadone dose and no contraindications to buprenorphine/naloxone, how should the transition to Suboxone (buprenorphine/naloxone) be carried out?
Should I maintain the current regimen of valproic acid 500 mg once daily and quetiapine 100 mg in the morning and 200 mg at bedtime?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.