Treatment Plan for Cartilage Loss in the Knee
Begin with a comprehensive non-pharmacological and pharmacological approach before considering surgical intervention, with treatment selection based primarily on defect size, patient age, and symptom severity. 1
Initial Non-Surgical Management
Non-Pharmacological Interventions (First-Line)
Patient education about osteoarthritis and self-management programs combining exercise with weight loss (if overweight/obese) are strongly recommended as foundational therapy. 1
Physical therapy should be offered as part of the comprehensive management plan, focusing on optimizing and maintaining joint function. 1
Soft braces for knee OA may provide symptomatic benefit in selected patients. 1
Pharmacological Management
Oral NSAIDs are the mainstay of pharmacologic treatment and are strongly recommended over all other oral medications for knee cartilage loss/osteoarthritis. 1 Use the lowest effective dose for the shortest duration possible, with monitoring for gastrointestinal, cardiovascular, and renal adverse effects. 1
Additional pharmacological options include:
Topical NSAIDs and capsaicin are recommended, particularly for patients who cannot tolerate oral NSAIDs. 1
Acetaminophen is conditionally recommended but has very small effect sizes; it may be appropriate for short-term use in patients with contraindications to NSAIDs (maximum 3 gm daily in divided doses with hepatotoxicity monitoring). 1
Duloxetine is conditionally recommended for knee OA and may provide benefit through central pain modulation. 1
Intra-articular corticosteroid injections are strongly recommended for symptomatic relief, providing short-term efficacy. 1 Use ultrasound guidance when available for accurate delivery, though not required for knee joints. 1
Intra-articular hyaluronic acid injections are an option, though corticosteroid injections are conditionally recommended over hyaluronic acid based on higher quality evidence. 1, 2
Important caveat: Glucosamine and chondroitin (SADOA) are thought to prevent cartilage degeneration but have not been shown to slow or reverse cartilage destruction. 3
Surgical Management Algorithm
Surgical intervention is indicated when conservative management fails, with technique selection based primarily on defect size and characteristics. 4, 5
Small Focal Defects (<2 cm²)
For small, contained cartilage defects:
Chondroplasty (surgical debridement) alone is appropriate for symptomatic relief, though it does not prevent osteoarthritis progression. 3, 4
Osteochondral autograft transfer is indicated for small focal defects with intact subchondral bone. 3, 4
Microfracture is NOT superior to chondroplasty alone and carries potential adverse effects including cyst and intralesional osteophyte formation; therefore, it should not be routinely recommended as the sole treatment. 3, 4
Critical consideration: Microfracture indications (when used) require minimal OA, a focal contained lesion <4 cm², and intact subchondral bone. 1
Medium Defects (2-3 cm²)
For defects between 2-3 cm²:
Microfracture with debridement remains the most frequently used approach in this size range, though controversy exists. 6
Consider marrow-stimulating procedures for focal defects in this range. 3
Large Defects (>3 cm²)
For larger cartilage defects exceeding 3 cm²:
Autologous chondrocyte implantation (ACI) or matrix-induced ACI is the primary recommendation for large defects. 3, 4, 6
Osteochondral allograft transfer is indicated for larger defects, particularly those involving subchondral bone. 3, 4
Particulated juvenile allograft cartilage shows good to excellent short-term results but lacks long-term outcome data. 4
Special Considerations
Address concomitant pathology:
Limb malalignment, meniscus deficiency, ligament injuries, and bone defects must be addressed to achieve successful outcomes from any cartilage restoration procedure. 4
Osteotomy near the knee joint is indicated for axial realignment when unilateral knee OA causes axis deviation. 3
Age considerations: Two-thirds of European surgeons consider age 50 as the upper limit or no limit for interventional cartilage surgery. 6
Critical Pitfalls to Avoid
Do not perform surgical debridement as the sole treatment expecting to prevent OA progression—it provides only symptomatic relief. 3
Do not routinely use MRI for diagnosis—plain radiography is sufficient for known or suspected OA; MRI should be reserved for specific indications. 1
Do not rely on microfracture alone for defects >2 cm²—it has not demonstrated superiority and may cause complications. 4
Recognize that fibrocartilage repair tissue (produced by most techniques) lacks the biomechanical properties of hyaline cartilage and generally deteriorates over time. 7
Preservation of native cartilage is always preferred if an osteochondral fragment can be salvaged. 4