How is a bony irregularity of the tibial tubercle managed?

Management of Bony Irregularities of Tibial Tubercle

The management of bony irregularities of the tibial tubercle should focus on addressing the underlying cause, with surgical intervention recommended for persistent cases that affect function, pain, or stability of the knee joint.

Assessment and Initial Management

• Evaluate for localized tibial tenderness, which correlates with bone abnormalities and healing status 1

• Determine if the irregularity is:

  • Congenital (e.g., congenital pseudarthrosis)
  • Developmental (e.g., Osgood-Schlatter disease)
  • Traumatic (e.g., fracture)
  • Neoplastic (e.g., osteochondroma)

• Initial management for minor bony irregularities:

  1. Pain-free walking progression
  2. Activity modification to avoid aggravating activities
  3. Strengthening of surrounding musculature (particularly calf, tibialis anterior, core and pelvic muscles) 1

Surgical Management Options

For Patellofemoral Instability with Tibial Tubercle Irregularity

When bony irregularities contribute to patellofemoral instability, tibial tubercle osteotomy is indicated 2, 3:

1. Fulkerson Osteotomy (Anteromedialization):

   • Recommended for patients with lateralization of the tibial tubercle
   • Addresses increased tibial tubercle-to-trochlear groove distance
   • Particularly effective when Q-angle measurements show chronic instability 2

2. Anteriorization and Distalization:

   • Indicated for patellar instability with associated patella alta
   • Corrects patellar height and decreases contact pressure across the patellofemoral joint 3

For Congenital Pseudarthrosis of the Tibial Tubercle

For congenital pseudarthrosis affecting the tibial tubercle region, the following approaches are recommended 1, 4:

1. Combined Fixation Technique:

   • External fixation (Ilizarov) with intramedullary fixation
   • 84% primary union rate
   • 5.62 months mean union time
   • 22.3% refracture rate 4

2. Cross-Union Technique:

   • Creates tibiofibular fusion to increase stability
   • 100% primary union rate
   • 4.5 months mean union time
   • 22.5% refracture rate
   • Particularly beneficial for younger patients or those with high-risk anatomical features 1, 4

3. Not Recommended:

   • Intramedullary rods (IMR) alone (85% refracture rate)
   • Fixed nails (Rush rods)
   • Locking compression plate (LCP) alone 4

For Tibial Tubercle Osteochondroma

For osteochondroma of the tibial tubercle (rare condition that can mimic Osgood-Schlatter disease):

• Excision biopsy is the recommended treatment 5
• Special consideration needed for skeletally immature patients to avoid damage to the apophysis and extensor mechanism attachment

Post-Treatment Rehabilitation

1. Progressive Loading Protocol:

   • Begin with pain-free walking
   • Progress to higher-impact activities only when pain-free with walking 1
   • Address lower extremity biomechanical abnormalities 1

2. Strength Training Focus:

   • Calf and tibialis anterior strengthening
   • Core and pelvic muscle strengthening
   • Progress to plyometric exercises and running drills when appropriate 1

3. Monitoring:

   • Follow-up until skeletal maturity for congenital conditions
   • Monitor for refracture, which can be a common complication 4
   • Assess ankle function, limb length discrepancies, and deformity correction 4

Common Pitfalls and Considerations

• Failure to identify the correct anatomical landmarks can lead to surgical complications. Gerdy's tubercle serves as a reliable landmark for knee approaches 6
• Refracture is the most common complication after primary healing, especially with certain treatment techniques 4
• In skeletally immature patients, special consideration must be given to avoid growth disturbances 5
• For extensive exposure during total knee arthroplasty, tibial tubercle osteotomy using a long osteoperiosteal segment can provide excellent exposure with low complication rates 7

By following this structured approach to managing bony irregularities of the tibial tubercle, clinicians can optimize outcomes while minimizing complications and recurrence rates.