Hip Microfracture: Indications, Technique, and Outcomes.

Microfracture is a marrow-stimulating technique used in the hip to treat cartilage defects associated with femoro-acetabular impingement, instability, or traumatic hip injury. These defects have a low probability of healing spontaneously and therefore often require surgical intervention. Originally adapted from the knee, microfracture is part of a spectrum of cartilage repair options that include palliative procedures such as debridement and lavage, reparative procedures such as marrow-stimulating techniques (abrasion arthroplasty and microfracture), and restorative procedures such as autologous chondrocyte implantation and osteochondral allograft/autografts. The basic indications for microfracture of the hip include focal and contained lesions typically less than 4 cm in diameter, full-thickness (Outerbridge grade IV) defects in weightbearing areas, unstable lesions with intact subchondral bone, and focal lesions without evidence of surrounding chondromalacia. Although not extensively studied in the hip, there are some small clinical series with promising early outcomes. Although the widespread use of microfracture in the hip is hindered by difficulties in identifying lesions on preoperative imaging and instrumentation to circumvent the femoral head, this technique continues to gain acceptance as an initial treatment for small, focal cartilage defects.