What is the treatment for transient patellar dislocation with edema in the superolateral aspect of Hoffa's (fatty tissue) fat pad and a tibial tuberosity to trochlear groove distance of 13mm?

Treatment for Transient Patellar Dislocation with Hoffa's Fat Pad Edema and Increased TT-TG Distance

For a patient with transient patellar dislocation with edema in the superolateral aspect of Hoffa's fat pad and a tibial tuberosity to trochlear groove (TT-TG) distance of 13mm, surgical intervention with tibial tuberosity transfer is recommended as the most effective treatment.

Initial Evaluation

• Radiographs should be the initial imaging modality for evaluation, including anteroposterior, lateral, and patellofemoral views to assess patellar alignment and potential fractures 1
• MRI is the preferred advanced imaging modality to further characterize bone and soft-tissue injuries associated with transient lateral patellar dislocation, including Hoffa's fat pad edema 1
• The TT-TG distance of 13mm is considered abnormal (normal is typically <10mm) and is a significant predisposing factor for recurrent patellar instability 2, 3

Treatment Algorithm

Conservative Management (Initial Approach)

• Relative rest and activity modification to reduce loading of the damaged structures 1
• Cryotherapy (ice applications) for 10-minute periods to provide acute pain relief 1
• Eccentric strengthening exercises focusing on the quadriceps to improve patellar stability 1
• Short-term NSAIDs for pain relief, though they don't affect long-term outcomes 1

Surgical Management

• Surgical intervention is indicated due to the presence of multiple risk factors:

  1. Increased TT-TG distance (13mm)
  2. Superolateral Hoffa's fat pad edema (indicating patellofemoral maltracking)
  3. History of patellar dislocation 4, 2

• Tibial tuberosity transfer is the recommended surgical procedure as it directly addresses the excessive TT-TG distance and can correct patellofemoral maltracking 4, 2

• The procedure involves:

  1. Medial transfer of the tibial tuberosity to reduce the TT-TG distance to approximately 9mm 2
  2. May be combined with lateral release to address lateral patellar tilt 2
  3. In some cases, combined with medial patellofemoral ligament reconstruction if there is excessive patellar tilt 4

Expected Outcomes

• Studies show good outcomes with tibial tuberosity transfer, with mean post-operative TT-TG distance reduction from 16.8mm to 8.9mm 2
• Recurrent dislocation rate after tibial tuberosity transfer is approximately 15.2% 2
• Patient-reported outcomes show good functional results with mean Kujala scores of 88 and IKDC scores of 80.4 2

Risk Factors and Considerations

• Superolateral Hoffa's fat pad edema is strongly associated with patellar maltracking and may precede clinically significant chondrosis 5
• Patella alta, increased TT-TG distance, and increased trochlear angle are predisposing factors for Hoffa's fat pad syndrome 3
• The combination of these findings (Hoffa's fat pad edema and increased TT-TG distance) indicates a high risk for recurrent patellar instability if treated conservatively 5, 3

Surgical Timing

• In the absence of severe associated injuries, early definitive surgical intervention is recommended within the first 24 hours to reduce local and systemic complications 1
• If there are associated severe injuries or the patient is unstable, a delayed approach with temporary stabilization followed by definitive surgery once the patient is stable is recommended 1

Post-Surgical Considerations

• Regular radiographic follow-up to assess patellar alignment and healing of the tibial tuberosity transfer 1
• Progressive rehabilitation focusing on quadriceps strengthening and patellar stabilization exercises 1
• Monitoring for potential complications including recurrent instability, pain, or patellofemoral arthritis 1