Fulkerson Surgery Technique: Understanding Patellofemoral Instability, Procedure, Recovery, and Risks

What is Fulkerson Surgery Technique?

The Fulkerson surgery technique, formally known as the Tibial Tubercle Osteotomy with Anteromedialization (TTO-AM), is a specialized orthopedic procedure designed to stabilize the patella (kneecap) and alleviate pain caused by chronic patellofemoral instability or maltracking.

Understanding Patellofemoral Instability

The patella, or kneecap, tracks within a groove at the end of the femur (thigh bone) called the trochlear groove. For healthy knee function, the patella must glide smoothly within this groove as the knee bends and straightens. Patellofemoral instability occurs when the patella repeatedly dislocates or subluxates (partially dislocates), often due to anatomical abnormalities, ligamentous laxity, or muscle imbalances. This instability can lead to pain, swelling, a feeling of the knee "giving way," and long-term cartilage damage (patellofemoral arthritis).

What is the Fulkerson Osteotomy?

The Fulkerson osteotomy is a surgical procedure that involves precisely cutting and repositioning the tibial tubercle – the bony prominence on the front of the tibia (shin bone) where the patellar tendon attaches. By moving this attachment site, the surgeon can change the angle and position of the patella relative to the femur, thereby improving its tracking within the trochlear groove.

• Key Principles: The technique is based on two primary principles:
  • Medialization: Moving the tibial tubercle medially (towards the midline of the body) reduces the lateral (outward) pull on the patella, which is often a contributing factor to instability.
  • Anteriorization: Moving the tibial tubercle anteriorly (forward) helps to lift the patella slightly out of the trochlear groove, decreasing the contact pressure between the patella and femur, especially during knee flexion, which can reduce pain in cases of patellofemoral pain syndrome.
• Anatomical Rationale: The procedure directly addresses biomechanical issues such as an increased Q-angle (the angle between the quadriceps muscle and the patellar tendon), trochlear dysplasia (a shallow or flat trochlear groove), or an excessively lateralized tibial tubercle. By correcting these anatomical predispositions, the Fulkerson technique aims to restore proper patellar kinematics.

Indications for Fulkerson Surgery

Fulkerson surgery is typically considered for individuals who experience:

• Recurrent Patellar Dislocations or Subluxations: When conservative treatments like physical therapy and bracing have failed.
• Chronic Patellofemoral Pain Syndrome: Especially when associated with patellar maltracking and evidence of focal cartilage lesions on the undersurface of the patella or trochlea.
• High Q-angle: Contributing significantly to lateral patellar tracking.
• Failed Previous Patellar Stabilization Surgeries: In some complex cases.
• Skeletally Mature Patients: The procedure is generally not performed on growing individuals due to potential growth plate disturbance.

The Surgical Procedure

The Fulkerson osteotomy is performed under general or regional anesthesia. The steps typically involve:

• Pre-operative Assessment: Detailed imaging (X-rays, MRI, CT scan) is used to precisely map the patient's unique knee anatomy and determine the optimal vector for tubercle repositioning.
• The Incision and Tibial Tubercle Osteotomy: An incision is made on the front of the knee. The surgeon then carefully cuts a block of bone containing the tibial tubercle from the tibia.
• Medialization and Anteriorization: The bony block, along with its attached patellar tendon, is then shifted medially and/or anteriorly to the predetermined, optimal position. The precise degree of shift is crucial and is guided by pre-operative planning and intra-operative assessment of patellar tracking.
• Fixation: Once the ideal position is achieved, the bony block is secured to the tibia using screws. These screws typically remain permanently but can be removed in a subsequent procedure if they cause irritation.
• Adjunctive Procedures: Depending on the individual's specific pathology, the Fulkerson osteotomy may be combined with other procedures, such as a lateral retinacular release (cutting a tight ligament on the outside of the kneecap) or a medial patellofemoral ligament (MPFL) reconstruction (reconstructing a key stabilizing ligament on the inside of the kneecap).

Benefits and Expected Outcomes

The primary goal of Fulkerson surgery is to stabilize the patella, reduce pain, and prevent further damage to the knee joint.

• Improved Patellar Tracking: Directly addresses the biomechanical cause of instability.
• Reduced Pain: Particularly in activities involving knee flexion and loading.
• Decreased Risk of Recurrent Dislocations: Significantly lowers the likelihood of the kneecap dislocating again.
• Enhanced Function and Quality of Life: Allows patients to return to daily activities and sports with greater confidence and less discomfort.

Potential Risks and Complications

As with any surgical procedure, Fulkerson surgery carries potential risks, including:

• Infection: At the surgical site.
• Bleeding: Hematoma formation.
• Nerve or Vascular Damage: Though rare, injury to surrounding structures is possible.
• Non-union or Malunion: The bony block may not heal properly or may heal in an incorrect position.
• Hardware Irritation: Screws may become prominent or cause discomfort, requiring removal.
• Stiffness: Limited range of motion in the knee.
• Recurrence of Instability: Though the goal is stabilization, a small percentage of patients may still experience some instability.
• Anterior Knee Pain: Can persist in some cases, despite improved tracking.
• Compartment Syndrome: A rare but serious condition involving increased pressure in the lower leg.

Recovery and Rehabilitation

Rehabilitation is a critical component of successful recovery after Fulkerson surgery. It is typically guided by a physical therapist and progresses in phases.

• Immediate Post-operative Phase (Days 0-2 weeks):
  • Pain management and wound care.
  • Protection of the surgical site, often with a brace locked in extension or limited flexion.
  • Non-weight-bearing or partial weight-bearing with crutches.
  • Gentle range of motion exercises (e.g., heel slides) as tolerated and prescribed.
  • Isometric quadriceps exercises to prevent atrophy.
• Early Rehabilitation (Weeks 1-6):
  • Gradual increase in weight-bearing as bone healing progresses.
  • Progressive range of motion exercises to achieve full extension and increasing flexion.
  • Initiation of gentle strengthening exercises for the quadriceps, hamstrings, and glutes (e.g., straight leg raises, glute sets).
  • Emphasis on proper gait mechanics.
• Intermediate Rehabilitation (Weeks 6-12):
  • Continued strengthening with increased resistance (e.g., leg press, knee extensions, hamstring curls).
  • Introduction of balance and proprioception exercises.
  • Low-impact cardiovascular activities (e.g., stationary cycling, elliptical).
  • Focus on restoring functional movement patterns.
• Advanced Rehabilitation (Months 3-6+):
  • Sport-specific training and plyometrics, if applicable.
  • Agility drills and cutting movements.
  • Progressive return to higher-impact activities.
  • Continued focus on strength, endurance, and neuromuscular control.
• Return to Activity: Full return to unrestricted activities and sports can take 6-12 months or longer, depending on the individual's healing, compliance with rehabilitation, and the demands of their activity.

Is Fulkerson Surgery Right for You?

The decision to undergo Fulkerson surgery is a significant one that should be made in consultation with an experienced orthopedic surgeon. It is typically reserved for patients who have exhausted conservative treatment options and continue to experience significant pain and instability due to specific patellofemoral biomechanical issues. A thorough evaluation, including physical examination and advanced imaging, is essential to determine if this specialized procedure is the most appropriate course of action.

Conclusion

The Fulkerson surgery technique is a well-established and effective orthopedic procedure for addressing chronic patellofemoral instability and pain caused by patellar maltracking. By precisely repositioning the tibial tubercle, it aims to restore proper patellar kinematics, reduce symptoms, and improve long-term knee function. While requiring a dedicated rehabilitation period, it offers a significant solution for carefully selected patients seeking to regain stability and return to an active lifestyle.