FAI Surgery: Procedure, Recovery, and Outcomes

What is FAI Surgery?

FAI surgery, or femoroacetabular impingement surgery, is a corrective orthopedic procedure performed to reshape the bones of the hip joint and repair associated soft tissue damage, aiming to eliminate the abnormal contact that causes pain and limits motion in individuals with FAI.

Understanding FAI: The Underlying Condition

Femoroacetabular Impingement (FAI) is a condition where the bones of the hip joint — the femoral head (ball) and the acetabulum (socket) — abnormally contact each other, leading to pinching and damage to the articular cartilage and the labrum (a ring of cartilage that rims the acetabulum). This abnormal contact typically results from subtle deformities in the bone structure, which can be present from birth or develop during growth.

There are three primary types of FAI:

• Cam Impingement: Occurs when the femoral head is not perfectly round, causing a "bump" that grinds against the acetabulum, particularly during hip flexion and internal rotation.
• Pincer Impingement: Results from an overgrowth of the acetabular rim, which covers too much of the femoral head, leading to the labrum being pinched between the rim and the femoral neck.
• Mixed Impingement: A combination of both Cam and Pincer deformities, which is the most common presentation.

Symptoms of FAI often include:

• Groin pain, especially with prolonged sitting, walking, or during activities involving deep hip flexion (e.g., squatting, lunging).
• Stiffness or a catching sensation in the hip.
• Pain radiating to the side or back of the hip.
• Reduced range of motion.

Diagnosis typically involves a physical examination, specific provocative tests, and imaging studies such as X-rays, MRI (often with contrast), and occasionally CT scans to visualize the bony anatomy and soft tissue damage.

When is FAI Surgery Recommended?

FAI surgery is generally considered when conservative treatments have failed to alleviate symptoms and improve function. Conservative approaches usually include:

• Activity modification.
• Non-steroidal anti-inflammatory drugs (NSAIDs).
• Physical therapy focused on improving hip strength, stability, and mobility, while avoiding aggravating movements.
• Corticosteroid injections into the hip joint.

Surgery becomes a viable option when:

• Persistent Pain and Dysfunction: The individual continues to experience significant pain and limitations in daily activities or athletic performance despite non-surgical interventions.
• Structural Abnormalities: Imaging confirms bony impingement and/or significant labral or cartilage damage.
• Prevention of Progression: There's a concern that continued impingement could lead to further joint degeneration and early onset osteoarthritis.

Types of FAI Surgery: Arthroscopic vs. Open

The vast majority of FAI surgeries today are performed using hip arthroscopy, a minimally invasive technique. In some complex cases, or when other concurrent procedures are required, an open surgical approach (arthrotomy) may be used, involving a larger incision to directly visualize the hip joint.

Hip arthroscopy is preferred due to:

• Smaller incisions.
• Reduced soft tissue disruption.
• Potentially faster recovery times.
• Lower risk of complications compared to open surgery.

The Arthroscopic FAI Surgery Procedure

Hip arthroscopy for FAI is typically performed under general anesthesia, sometimes combined with a spinal block. The procedure involves:

• Patient Positioning: The patient's leg is often placed in traction to distract the hip joint, creating space for instruments and visualization.
• Incision (Portals): Several small incisions (typically 2-4, each about 1 cm) called "portals" are made around the hip.
• Arthroscopic Access: An arthroscope (a small camera) is inserted through one portal, providing the surgeon with a magnified view of the joint on a monitor. Specialized instruments are inserted through the other portals.
• Debridement and Reshaping (Osteoplasty):
  • For Cam lesions, the surgeon uses a burr to remove the excess bone from the femoral head-neck junction, restoring its normal spherical shape.
  • For Pincer lesions, excess bone from the acetabular rim is trimmed (acetabuloplasty).
• Labral Repair or Reconstruction: If the labrum is torn, it is either repaired by reattaching it to the acetabular rim using small anchors or, in cases of severe damage, parts of it may be debrided or reconstructed using a tissue graft.
• Cartilage Assessment: The surgeon will assess the articular cartilage for any damage and may perform microfracture or debridement if necessary.
• Closure: Once the necessary corrections are made, the instruments are removed, and the small incisions are closed with sutures or sterile strips.

Recovery and Rehabilitation Post-Surgery

Recovery from FAI surgery is a structured process, with physical therapy being a critical component.

• Immediate Post-Op (Days 0-14):
  • Pain management (medication, ice).
  • Crutches for protected weight-bearing (often 2-6 weeks, depending on the procedure).
  • Limited hip range of motion, especially avoiding deep flexion or rotation, to protect repairs.
  • Continuous Passive Motion (CPM) machine may be used to gently move the hip.
• Early Rehabilitation (Weeks 2-6):
  • Gradual increase in weight-bearing.
  • Initiation of gentle range of motion exercises.
  • Introduction of isometric strengthening for hip muscles.
  • Focus on restoring normal gait patterns.
• Intermediate Rehabilitation (Weeks 6-12):
  • Progression to resisted strengthening exercises.
  • Improvement in balance and proprioception.
  • Increased functional activities.
• Advanced Rehabilitation (Weeks 12+):
  • Sport-specific drills for athletes.
  • Plyometric and agility training.
  • Gradual return to full activity, which can take 4-6 months, or even up to a year for high-level athletes.

Adherence to the physical therapy protocol is paramount for optimal outcomes, as it helps restore strength, flexibility, and stability to the hip joint.

Potential Risks and Complications

While hip arthroscopy for FAI is generally safe, as with any surgical procedure, there are potential risks:

• General Surgical Risks: Infection, bleeding, adverse reaction to anesthesia, blood clots (DVT).
• Nerve Damage: Temporary or, rarely, permanent numbness or weakness due to nerve irritation or damage (e.g., pudendal nerve, lateral femoral cutaneous nerve).
• Residual Impingement: Incomplete bone resection leading to persistent symptoms.
• Over-Resection: Excessive bone removal, potentially leading to instability or fracture.
• Stiffness: Formation of scar tissue limiting hip motion.
• Heterotopic Ossification: Abnormal bone growth in soft tissues around the joint.
• Persistent Pain: Despite successful surgery, some individuals may continue to experience pain.
• Failure of Labral Repair: The repaired labrum may not heal adequately.

Expected Outcomes and Long-Term Outlook

The goal of FAI surgery is to alleviate pain, improve hip function, and potentially reduce the risk of future osteoarthritis.

• Pain Relief: Most patients experience significant reduction in hip pain.
• Improved Function: Enhanced range of motion and ability to perform daily activities and return to sport.
• Return to Activity: Many individuals, including athletes, are able to return to their previous level of activity, though this varies based on the severity of the initial condition and adherence to rehab.
• Osteoarthritis Prevention: While surgery can address the mechanical cause of impingement and prevent further damage, it does not guarantee the prevention of future osteoarthritis, especially if significant cartilage damage was already present.

Success rates for FAI surgery are generally reported to be good to excellent in 70-90% of cases, particularly for those with isolated FAI and minimal pre-existing arthritis. Long-term studies are ongoing to fully understand the impact of FAI surgery on the development of osteoarthritis.

Who Performs FAI Surgery?

FAI surgery is performed by orthopedic surgeons who have specialized training and expertise in hip arthroscopy. Given the complexity and delicate nature of the hip joint, it is crucial to seek a surgeon with significant experience in this specific procedure to ensure the best possible outcomes.