Debridement, Microfracture, and Osteochondral Autograft Transfer for the Treatment of Cartilage Defects

All three techniques discussed in this chapter are treatment options for small articular cartilage defects, predominately because of their low invasiveness. Debridement is mostly indicated for the treatment of (1) incidental lesions discovered during surgery directed at other joint pathology, such as meniscectomy and ACL reconstruction; and (2) lesions in lower demand patients who are reluctant to undergo other cartilage repair procedures that are more invasive and/or require long rehabilitation. Debridement is also a good initial treatment option for lesions that are deemed borderline or too large for microfracture or osteochondral autograft transfer (OAT) because it does not appear to compromise later treatment with autologous chondrocyte implantation (ACI).

Microfracture is a minimally invasive option whose indications have been refined in the last few years through multiple investigations. However, unlike chondroplasty, patients can be made worse in up to 13% of cases and it should only be used for incidental lesions after an informed discussion with the patient and obtaining their consent. It has a high success rate when used appropriately for the treatment of small (< 2–4cm ² ) defects in the femoral condyles of younger (< 35–40 years) patients with acute defects.

Larger defects and those located in the patellofemoral joint deteriorate after 24–36 months. Not all defect sizes, whether small or large, have the same clinical improvement nor responsiveness as ACI as demonstrated in the Summit Trial.

OAT is generally indicated for the treatment of small (< 2–4 cm ² ) defects in the femoral condyles and trochlea, but not the patella. The recommendation for size is based on the limited availability of cartilage elsewhere in the knee (donor site morbidity); and to minimize the complication of plug necrosis, which is seen more frequently in central plugs that are completely surrounded by other plugs and therefore have no direct contact with native bone for integration. Although lesions up to 4 cm ² have been indicated for OAT, it is our preference to use this technique for active, fit individuals as a first-line treatment with lesions 1–1.5 cm ² because it does not cause donor-site symptoms in these small lesions and results in a rapid return to sport (4–8 months) with a mature hyaline cartilage repair.