What is the treatment for chondrosis of the acetabulum and femoral head?

Treatment of Chondrosis of the Acetabulum and Femoral Head

For chondrosis (cartilage damage) of the acetabulum and femoral head, treatment should be stratified by lesion size: microfracture for lesions <2 cm², osteochondral allograft transplantation for lesions 2-6 cm², and total hip arthroplasty for lesions >6-8 cm² in appropriately selected patients. 1

Patient Selection Criteria

Before considering any joint-preserving surgical intervention, patients must meet specific criteria 1:

• Age: Between skeletal maturity and 50 years 1
• Radiographic findings: Minimal (Tönnis grade ≤1) or no osteoarthritis 1
• Exclusions: No inflammatory arthritis, no bipolar lesions (both acetabulum and femoral head involved) 1
• Lesion characteristics: Well-contained, full-thickness defects 1
• Functional capacity: Ability to perform rigorous postoperative physical therapy 1

Treatment Algorithm for Femoral Head Lesions

Small Lesions (<2 cm²)

First-line treatment: Microfracture 1, 2

• The procedure involves debriding friable cartilage to create a well-contained lesion with perpendicular edges of healthy cartilage, then using an awl to create 3-4 mm deep holes spaced 3-4 mm apart in the subchondral bone 1
• This releases marrow cells and growth factors that form fibrocartilage to fill the defect 1, 2
• Clinical outcomes show 93% fill rate with good-quality cartilage at second-look arthroscopy 1, 2
• Patients treated with microfracture demonstrate significantly higher functional scores compared to simple chondroplasty 1

Second-line options: Mosaicplasty (autologous osteochondral transplantation) or osteochondral allograft (single plug) 1

Medium Lesions (2-6 cm²)

First-line treatment: Osteochondral allograft transplantation 1, 2

• Indicated for patients ≤50 years with no osteoarthritis and lesions >2.5 cm² or substantial subchondral bone loss 1, 2
• The technique involves debriding the lesion to healthy cartilage, drilling to accept the allograft, and press-fitting a size-matched cadaveric donor graft 1
• Provides immediate mechanically functioning hyaline cartilage with superior properties compared to fibrocartilage 1
• Clinical success rates of 80% have been reported in non-steroid-induced osteonecrosis cases 1

Second-line treatment: Osteochondral transplantation or microfracture (for lesions not identified preoperatively) 1

Large Lesions (6-8 cm²)

Treatment: Osteochondral allograft transplantation 1

• Preferred over autograft due to donor site limitations with autograft 3
• Allows management of larger lesions that are difficult to address with other techniques 1

Very Large Lesions (>8 cm²)

Treatment: Total hip arthroplasty 1

• Recommended when joint preservation is no longer feasible 1

Treatment Algorithm for Acetabular Lesions

Small to Medium Lesions (<6 cm²)

Treatment: Microfracture 1

• Same technique as described for femoral head lesions 1
• For delaminated chondral flaps with viable cartilage, suture repair may be considered 1

Large Lesions (>6 cm²)

Treatment: Consider conversion to total hip arthroplasty 1

• Joint preservation becomes increasingly difficult with larger acetabular defects 1

Special Considerations and Alternative Techniques

Matrix-Assisted Autologous Chondrocyte Implantation (MACI)

• For lesions >2 cm² with Tönnis grade 2 osteoarthritis, MACI performed arthroscopically showed superior outcomes compared to simple debridement (mean Harris Hip Score 87.4 vs. 56.3 at 74 months follow-up) 1
• Important limitation: MACI is currently used in Europe but not FDA-approved in the United States 1
• Traditional ACI requires surgical dislocation with risk of osteonecrosis, making it less favorable 1

Delaminated Cartilage Repair

• For healthy-appearing delaminated cartilage, repair with sutures or fibrin adhesive may be attempted 1
• Significant improvement in pain and function scores have been reported with fibrin adhesive repair (mean Modified Harris Hip Score pain subscale improved from 21.8 to 35.8) 1
• This technique is appropriate only for small lesions of delaminated cartilage 1

Common Pitfalls and Caveats

Critical exclusions:

• Do not proceed with osteochondral allograft if bipolar lesions are present 3
• Meniscal/labral pathology must be addressed before or concurrent with cartilage treatment 3, 4

Avoid overtreatment:

• Microfracture performed too early (before 4-6 weeks) may lead to false-positive findings and unnecessary intervention 1
• The high sensitivity of early imaging can suggest pathology in physiologically immature joints 1

Stem cell therapy:

• Not currently recommended due to heterogeneity and lack of standardization 3, 2, 4

Technical considerations:

• Osteochondral allograft viability decreases substantially after 28 days of storage 1
• Surgical dislocation for traditional ACI carries risk of osteonecrosis 1
• Mosaicplasty has donor site morbidity limitations 1

Evidence Quality Note

The American Academy of Orthopaedic Surgeons acknowledges that the literature supporting these joint-preserving techniques is limited to small case series and case reports with no long-term studies or control groups 1, 2. However, the treatment algorithms provided represent the current best-practice consensus for managing these challenging lesions in appropriately selected patients who wish to avoid or delay total hip arthroplasty 1.