[Arthroscopically assisted therapy of avascular necrosis of the femoral head].

OBJECTIVE

Preservation of the hip joint function by treatment of the avascular necrosis of the femoral head in adults or at least avoiding progression.

METHODS

Avascular necrosis of the femoral head in adults in Steinberg stages I-III. In patients with Steinberg stage IVa (subchondral collapse ≤ 15% of the articular surface, depression < 2 mm) hip joint salvage therapy in early stages of femoral head collapse.

METHODS

Manifest osteoarthritis of the hip joint. Joint infection. Relative contraindications: subchondral collapse > 15% of the articular surface or depression > 2 mm (Steinberg stage IVb and above). Persisting risk factors for a progression of avascular necrosis (e.g., alcohol abuse, chemotherapy, local irradiation, high-dose cortisone therapy) and obesity (BMI > 40).

METHODS

Arthroscopy of the hip joint in case of cartilage defects and/or potential collapse of the femoral head. Without collapse of the femoral head and absence of severe damage of the cartilage: core decompression using a guiding sleeve through a lateral approach (Steinberg II, III). Subsequently curettage of the necrotic area through a central drill hole and insertion of autogenic bone cylinders using an OATS harvester (Steinberg II b/c, III b/c). In Steinberg stage IVa, reconstruction of the outline of the femoral head is attempted by reduction of the impressed portion (under intraoperative fluoroscopy).

METHODS

Limited weight bearing (10 kg) of the operated leg for 6 weeks. In cases of large necrotic defects located directly beneath the subchondral bone (Steinberg IIIc) as well as subchondral collapse with flattening of the femoral head (Steinberg IVa) limited weight bearing (10 kg) for 12 weeks.

RESULTS

Early results of femoral head preserving therapy in 53 patients (56 hips, consecutively treated between June 2004 and December 2009) after 33 ± 20 months: success rate (no arthroplasty, no reoperation, no radiological progress associated with clinical symptoms) 86% for patients treated with Steinberg stages I-III. Failure of the head preserving therapy with concern to the mentioned criteria depending on the initial Steinberg stage: 0 (0%) for stage I, 2 (10%) for stage II, 3 (25%) for stage III, and 4 (31%) for stage IVa.