[Shortening osteotomy for alloarthoplastic joint replacement for hip dislocation in adults].

OBJECTIVE: Total hip arthroplasty to create an articulating hip joint. Acetabular cup implantation in the original rotational center of the pelvis. Simultaneous femoral shortening osteotomy to prevent neurovascular damage and equalize leg length in patients with unilateral occurrence. INDICATIONS: Developmental dysplasia of the hip (DDH) in adults; type 3 and 4 dislocation according to Crowe. CONTRAINDICATIONS: Cerebrospinal dysfunction with permanent restriction of coordination ability, muscular dystrophies, and multiple malformations of the musculoskeletal system. Apparent disturbance of the bone metabolism. SURGICAL TECHNIQUE: The Watson-Jones interval approach to the hip joint is used to avoid functional disorders of the hip abductors. After preparation of the proximal femur and femoral neck resection, adjustment of the non-regularly developed acetabular cavity with reduced anterior coverage takes place. The cup component is implanted and the interval between the vastus intermedius and the vastus lateralis below the lesser trochanter examined. Loss of periosteum of the femoral cortex due to blunt spreading is to be avoided. Following the femoral shortening osteotomy initially the preparation of the distal bone segment takes place to adjust the endofemoral canal for shaft implantation in the following preparation of the metaphyseal segment. Afterwards osteotomy-bridging implantation of a cementless, distal anchoring stem design is performed. POSTOPERATIVE MANAGEMENT: Partial weight bearing of the leg with 20 kp is necessary for 6 weeks combined with therapy of existing contractures and active pelvic rotation training. Within 10 postoperative weeks full weight bearing is usually reached. After this period mobilization without crutches is possible. Inpatient rehabilitation is possible after bony recovery of the femoral osteotomy.
RESULTS: From 1993 to 1999, the first 15 total hip arthroplasties were performed in adult patients with DDH; they were treated with simultaneous femoral shortening osteotomy and without additive osteosynthesis. During the midterm follow-up (4.3 years), no failure of the femoral component was observed with complication-free osseous healing of the osteotomy. One cup revision was necessary in this period. The Merle d'Aubigné score increased from 8.2 preoperatively to 15.5 points.