Patella Dislocation: MPFL Reconstruction, Other Surgical Options, and Recovery

What is the name of the surgery for patella dislocation?

While there isn't a single, universal name for all surgeries addressing patella dislocation, the most common and definitive procedure, particularly for recurrent instability, is Medial Patellofemoral Ligament (MPFL) Reconstruction.

Understanding Patellar Dislocation

Patellar dislocation occurs when the kneecap (patella) completely slips out of its normal position in the trochlear groove at the end of the thigh bone (femur). This typically happens when the patella moves laterally (to the outside of the knee). It is a painful event that can damage the soft tissues supporting the kneecap, most notably the medial patellofemoral ligament, and sometimes the articular cartilage.

Causes and Risk Factors:

• Traumatic Injury: A direct blow to the knee or a sudden twisting motion.
• Anatomical Predisposition: Shallow trochlear groove, patella alta (high-riding patella), genu valgum (knock-knees), increased Q-angle (angle between quadriceps and patellar tendon), or muscle imbalances.
• Ligamentous Laxity: Generalized joint hypermobility.

Symptoms:

• Sudden, severe knee pain.
• Visible deformity of the knee.
• Inability to straighten or bend the knee.
• Swelling and bruising.
• A "popping" sensation at the time of injury.

Surgical Interventions for Patellar Dislocation

The primary goal of surgery for patella dislocation is to stabilize the kneecap and prevent future dislocations, restoring normal knee function. The specific surgical approach is highly individualized, depending on the underlying cause, the extent of damage, and the patient's anatomy and activity level.

The Primary Surgical Name: Medial Patellofemoral Ligament (MPFL) Reconstruction

The Medial Patellofemoral Ligament (MPFL) is a crucial soft tissue structure on the inner side of the knee that acts as the primary static stabilizer preventing the patella from dislocating laterally. In most patellar dislocations, the MPFL is torn or stretched beyond repair.

• MPFL Reconstruction Procedure: This surgery involves creating a new MPFL using a graft, typically taken from the patient's own hamstring tendon (autograft) or, less commonly, from a donor (allograft). The graft is then anchored to the patella and the medial femoral condyle in anatomically correct positions to replicate the function of the original ligament. This procedure effectively recreates the primary medial restraint to patellar movement.

Other Concurrent or Alternative Procedures

In addition to or in conjunction with MPFL reconstruction, other procedures may be performed to address specific anatomical abnormalities contributing to instability:

• Tibial Tubercle Osteotomy (TTO) / Medialization of the Tibial Tubercle: This procedure involves cutting a small block of bone where the patellar tendon attaches to the shin bone (tibial tubercle) and repositioning it. It can be moved medially (inward) to improve patellar tracking and reduce lateral forces, or distally (downward) if the patella is riding too high (patella alta).
• Trochleoplasty: If the trochlear groove (the groove in the femur where the patella sits) is too shallow or flat, making it difficult for the patella to track properly, a trochleoplasty may be performed. This involves reshaping the bone to create a deeper, more defined groove, providing a more stable path for the patella.
• Lateral Release: In some cases, the lateral retinaculum (tight tissue on the outside of the kneecap) can pull the patella excessively to the outside. A lateral release involves cutting these tight bands to reduce the lateral pull. However, this procedure is used less frequently as a standalone solution due to potential for over-release and medial instability.
• Capsular Plication/Repair: If the joint capsule on the medial side is excessively stretched but not completely torn, it may be tightened (plicated) or repaired to provide additional stability.
• Osteochondral Repair: If the dislocation caused damage to the articular cartilage or underlying bone (osteochondral injury), procedures to repair or restore this damaged tissue may be performed simultaneously.

When is Surgery Considered?

While some first-time patellar dislocations, especially those without significant associated injuries, may be managed conservatively with rehabilitation, surgery is typically considered in the following scenarios:

• Recurrent Dislocations: This is the most common indication for surgical intervention, as repeated dislocations significantly impact quality of life and increase the risk of progressive joint damage.
• First-Time Dislocation with Significant Ligamentous or Osteochondral Damage: If imaging reveals extensive tears of the MPFL or damage to the cartilage and bone surfaces, surgery may be recommended to prevent future instability and long-term arthritis.
• Persistent Instability: If the knee remains unstable despite a dedicated course of physical therapy and conservative management.
• Presence of Significant Anatomical Risk Factors: Correcting underlying structural issues (e.g., shallow trochlea, high-riding patella) often requires surgical intervention to achieve lasting stability.

The Recovery Process and Rehabilitation

Recovery after patella dislocation surgery is a structured and often lengthy process, crucial for a successful outcome. It typically involves:

• Initial Immobilization: The knee may be immobilized in a brace for a few weeks to protect the healing tissues.
• Pain and Swelling Management: Medications and RICE (Rest, Ice, Compression, Elevation) protocol.
• Physical Therapy: A comprehensive rehabilitation program is essential. It progresses through phases, including:
  • Early Phase: Focus on reducing swelling, restoring range of motion (gradually), and activating quadriceps muscles.
  • Intermediate Phase: Strengthening exercises for the quadriceps, hamstrings, glutes, and core; balance and proprioception training.
  • Advanced Phase: Plyometrics, agility drills, and sport-specific training to prepare for return to activity.
• Timeline: Full recovery and return to sport or high-impact activities can take anywhere from 6 to 12 months, depending on the complexity of the surgery and individual healing rates.

Potential Risks and Complications

As with any surgical procedure, there are potential risks and complications, including:

• General Surgical Risks: Infection, bleeding, adverse reaction to anesthesia, blood clots (DVT).
• Specific Complications:
  • Stiffness or Loss of Range of Motion: Scar tissue formation.
  • Persistent Pain: Due to nerve irritation, residual instability, or hardware issues.
  • Re-dislocation or Subluxation: Though less common after successful surgery, it can occur.
  • Nerve Damage: Injury to sensory nerves, leading to numbness around the incision.
  • Hardware Complications: Screws or anchors used in the procedure may become prominent or cause irritation, sometimes requiring removal.
  • Arthritis Progression: While surgery aims to prevent this, severe initial cartilage damage can still lead to long-term degenerative changes.

Conclusion and Long-Term Outlook

While Medial Patellofemoral Ligament (MPFL) Reconstruction is the most commonly performed and often definitive surgery for patella dislocation, especially for recurrent cases, the overall surgical strategy is tailored to the individual. A thorough evaluation by an orthopedic surgeon specializing in knee conditions is essential to determine the most appropriate surgical approach and optimize outcomes. Adherence to a rigorous and progressive rehabilitation program is equally critical for restoring knee stability, strength, and function, allowing individuals to return to their desired activities with confidence.