What is the recommended management of cam-type femoroacetabular impingement in a patient who recently underwent sacral fixation surgery?

Management of Cam-Type Femoroacetabular Impingement After Sacral Fixation Surgery

Arthroscopic cam resection (femoroplasty) should be considered for symptomatic cam-type FAI after sacral fixation surgery, but only after 3-6 months of failed conservative management, with heightened attention to spinopelvic mechanics given the patient's stiff spine syndrome from prior fusion. 1

Critical Context: Stiff Spine Syndrome

• Patients with spinal fusion to the sacrum have stiff spine syndrome, which fundamentally alters hip biomechanics and increases the risk of adverse events after hip surgery 2
• The lumbar-pelvic-femoral relationship is disrupted, placing increased mechanical demands on the hip joint and potentially exacerbating FAI symptoms 2
• This population requires more conservative surgical planning and may benefit from cemented femoral fixation if total hip arthroplasty becomes necessary 2

Initial Conservative Management (First-Line for 3-6 Months)

Conservative management must be attempted first, as 82% of adolescent and young adult patients with symptomatic FAI can be managed nonoperatively with significant outcome improvements 3

• Activity modification to avoid repetitive deep hip flexion combined with internal rotation movements 1
• Structured physical therapy program focusing on hip range of motion and core strengthening 1, 3
• NSAIDs for symptomatic pain relief during acute episodes 1, 4
• Image-guided intra-articular corticosteroid injection if symptoms persist after initial conservative measures 4, 3

Surgical Indications

Proceed to arthroscopic cam resection only when ALL of the following criteria are met:

• Persistent hip-related groin pain after 3-6 months of appropriate conservative management 1, 3
• Positive clinical examination findings (positive FADIR test reproducing the patient's pain) 1
• Radiographic confirmation of cam morphology (alpha angle >60°) with associated pathology 1
• MR arthrography demonstrating labral tears or chondral damage requiring concurrent treatment 1, 5

Surgical Technique Considerations

Arthroscopic femoroplasty with periportal capsulotomy preserves the iliofemoral ligament and provides adequate access for complete cam resection 6, 7

• Use comprehensive fluoroscopic assessment with 6 anteroposterior views (3 in extension at varying rotations, 3 in 50° flexion) performed before, during, and after resection 7
• Perform dynamic assessment of impingement-free range of motion in extension/abduction, flexion/abduction, and flexion/internal rotation positions 7
• Address posterolateral cam deformities by utilizing hip extension with the burr in the anterolateral portal 7
• Residual cam deformity is a leading cause of surgical failure—thorough intraoperative assessment is critical 7

Management of Associated Chondral Lesions

For grade 2-3 chondral lesions <2 cm² discovered during arthroscopy, microfracture produces substantially higher functional scores than chondroplasty alone 1, 5

• Microfracture achieves 93% defect fill with good-quality fibrocartilage at second-look arthroscopy 1, 5
• For larger defects >2 cm² with Tönnis grade 2 osteoarthritis, matrix-assisted autologous chondrocyte implantation (MACI) produces superior outcomes compared to simple debridement 1, 5
• For lesions >6-8 cm² or advanced osteoarthritis, total hip arthroplasty becomes the appropriate treatment 5

Postoperative Rehabilitation

• Pain-controlled progression to full weight bearing over 1-4 weeks 8
• Continuous passive motion therapy and stationary bike for 6 weeks to prevent intraarticular adhesions 8
• Structured rehabilitation protocol is essential following surgical intervention 4

Critical Pitfalls to Avoid

Never operate based on imaging findings alone—cam morphology without clinical symptoms does not warrant surgery 1

• Asymptomatic cam morphology (alpha angle >60°) is common in the general population and requires no treatment 1
• Delaying advanced imaging (MR arthrography) when surgery is being considered can lead to missed labral tears or chondral defects requiring concurrent treatment 1
• In patients with prior sacral fixation, failure to account for altered spinopelvic mechanics may lead to suboptimal outcomes or increased complication rates 2
• Incomplete cam resection is a leading cause of surgical failure—use systematic fluoroscopic and dynamic assessment intraoperatively 7

Expected Outcomes

• Mean improvement in modified Harris Hip Score of 20 points at 2-year follow-up with conservative management 3
• Average increase in Harris Hip Score of 20 points at 16-month follow-up after arthroscopic femoroplasty 9
• Complication rate of 1.5% with arthroscopic approach 9
• Patients with cam or combined cam-pincer impingement are 4.4 times more likely to require surgical intervention than those with isolated pincer deformities 3