[Core decompression ("conventional method") in atraumatic osteonecrosis of the hip].

OBJECTIVE: Retrograde drilling of a necrotic zone within the femoral head to reduce intraosseous pressure and stimulate revascularization.

INDICATIONS: Atraumatic osteonecrosis of the hip ARCO stage I (reversible) and ARCO stage II (potentially reversible) with a medial or central necrotic zone <30% or ARCO stage III with a subchondral fracture for reduction of pain.

CONTRAINDICATIONS: ARCO stage III C, ARCO stage IV (secondary osteoarthritis), stage-independent necrotic zone > 30%, infections.

SURGICAL TECHNIQUE: Supine position. Visualization of the necrotic zone via an image intensifier, approach is determined by using a Kirschner wire, laterodorsal skin incision on a level with the wire, longitudinal incision of iliotibial band and vastus lateralis muscle, drilling the necrotic zone with a 2-3 mm Kirschner wire, optionally placing more wires or a hollow drill, wound closure.

POSTOPERATIVE MANAGEMENT: Partial weightbearing with 20 kg for 6 weeks due to risk of fracture, followed by avoidance of jumping or sprinting for another 6 weeks; physiotherapy from day 1 after surgery, thromboembolic prophylaxis until full weightbearing is possible.

RESULTS: Results are dependent on ARCO stages and are promising in early stages.