Total hip arthroplasty with shortening subtrochanteric Z osteotomy in the treatment of developmental dysplasia with high hip dislocation.

BACKGROUND The work presents the results of total hip arthroplasty in the treatment of arthrosis secondary to for developmental dysplasia with high hip dislocation or corollary to previous surgery of dysplastic high riding hips. In all patients the cup was placed in its anatomical position. In order to avoid excessive lengthening of the operated limb and the associated complications, the femoral shaft was shortened by subtrochanteric Z osteotomy. The osteotomy site was stabilised with a cementless CDH stem. MATERIAL AND METHOD The technique was used in 10 women at an average age of 53. 4 years between 2006 and 2011. Five patients were operated on due to the degenerative changes secondary to developmental dysplasia with high dislocation of hip joint. The remaining patients had undergone surgery before. Angular osteotomy of the proximal femur was performed in four patients and total hip arthroplasty with high placement of the acetabular component in one. The average preoperative Harris Hip Score was 43.7. Preoperative shortening of the limb ranged from 4 to 10 cm, with an average of 6. 1 cm. RESULTS The patients were followed up for a mean of 28. 3 months. No postoperative nerve damage has been observed. The operated limb was lengthened in all patients (range: 2.5 to 5 cm, mean: 3.4 cm). Radiographic union at the osteotomy site was obtained after an average of 4.5 months. All patients reported complete or near-complete pain relief and improved function of the operated limb. By the last follow-up visit, the Harris Hip Score had increased to 86 points on average. CONCLUSIONS Subtrochanteric osteotomy of the femur reduces the risk of postoperative complications associated with excessive limb lengthening and facilitates access to the acetabulum. Total hip arthroplasty with shortening subtrochanteric Z-type osteotomy is a safe method in the treatment of degenerative changes secondary to developmental dysplasia with high hip dislocation.