What is the recommended treatment for a patient with a near full-thickness grade 3 chondral defect on the lateral femoral condyle and grade 3 and 4 chondral abnormalities on the lateral facet of the patella?

Treatment Recommendation for Grade 3 Lateral Femoral Condyle and Grade 3-4 Patellar Chondral Defects

For this patient with a 9 x 9 mm (0.81 cm²) near full-thickness grade 3 defect on the lateral femoral condyle and grade 3-4 patellar chondral abnormalities, arthroscopic microfracture is the recommended first-line treatment for both lesions, as the defect size is well below the 2 cm² threshold where microfracture demonstrates optimal outcomes. 1

Treatment Algorithm Based on Lesion Characteristics

Primary Treatment: Microfracture

• Microfracture is indicated for focal, contained chondral lesions <2 cm² in size with intact subchondral bone and healthy surrounding cartilage 2, 1
• Your patient's 0.81 cm² femoral condyle defect falls well within this size criterion 1
• The procedure involves debridement of friable cartilage to create a well-contained lesion with perpendicular edges, followed by creating 3-4 mm deep holes spaced 3-4 mm apart in the subchondral bone using an awl 2
• These perforations release marrow cells and growth factors that form fibrocartilage to fill the defect, achieving 93% fill rates with good-quality cartilage at second-look arthroscopy 2, 1

Evidence Supporting Microfracture for This Size Defect

• Patients with grade 2 or 3 chondral lesions <3 cm² treated with microfracture demonstrated substantially higher functional scores compared to chondroplasty alone 2
• Second-look arthroscopy studies show mean 91-93% defect fill at 17-20 months follow-up with good macroscopic cartilage quality 2, 3
• Functional outcomes improve significantly, with mean scores rising from 55 preoperatively to 78 points at 21-month follow-up 2

Management of Patellar Lesions

Addressing the Patellofemoral Compartment

• The grade 3-4 chondral abnormalities on the lateral patellar facet with reactive marrow changes can also be treated with microfracture if focal and contained 2, 1
• Patellar defects have significantly higher graft-related complications compared to femoral condyle lesions (p < 0.0001), making microfracture a safer initial approach than more complex cartilage restoration procedures 4
• The presence of reactive marrow changes indicates subchondral bone involvement but does not contraindicate microfracture if the bone plate remains intact 2

Patient Selection Criteria Met

Your patient appears to meet the key criteria for joint-preserving surgical management:

• Age between skeletal maturity and 50 years 1
• No evidence of diffuse osteoarthritis (only trace joint fluid noted) 1
• Focal full-thickness defects rather than bipolar kissing lesions 1
• Intact menisci and ligamentous structures 1

Critical Pitfall to Avoid

The single patient who failed microfracture in the acetabular studies had diffuse osteoarthritis at the time of initial treatment, achieving only 25% fill with grade 4 repair tissue 3. Your patient's imaging shows no diffuse osteoarthritis, only focal defects, which is favorable for microfracture success.

Alternative Treatments NOT Recommended for This Case

• Autologous chondrocyte implantation (ACI) or matrix-assisted ACI (MACI) are reserved for larger lesions >2 cm² and would represent overtreatment for a 0.81 cm² defect 2, 1
• Mosaicplasty (osteochondral autograft) is indicated for lesions <3 cm² but involves more donor site morbidity and is typically reserved for failed microfracture or osteochondral defects with substantial bone loss 2, 1
• Osteochondral allograft transplantation is recommended for medium-sized defects (2-6 cm²) with substantial subchondral bone loss, which does not apply here 1

Postoperative Considerations

• Patients must be able to perform a rigorous postoperative physical therapy regimen, which is essential for microfracture success 1
• Protected weight-bearing protocols are typically required for 6-8 weeks to allow fibrocartilage formation 2
• Continuous improvement is typically observed through 3 years postoperatively, with mean functional score improvements of 39 points at 5-year follow-up 5