Introduction The consequence of discongrency of the hip joint may be early, secondary osteoarthritis of the hip joint, that leads to important limits in movement abilities of an individual. The deficit of the femoral head coverage can be rather easily corrected, but only until the growth and maturation of the pelvis is completed. Redirection of the acetabular fragment can be performed by use of the periacetabular osteotomy according to Ganz. This type of the osteotomy is mainly used in the treatment of the acetabular displasia in patients with closed Y cartilage, but also in the treatment of the osteoarthritis of the hip joint. The Aim of the study was to present our early results of treatment of the patients with the secondary osteoarthritis of the hip joint by use of the periacetabular osteotomy according to Ganz.

Material and Methods. Our material consisted of 64 patients, 72 hip joints, operated on between 1998–2004. 20 patients (24 hip joints) were selected from this group. In these 20 patients the indication for the treatment was not only the acetabular displasia, but also osteoarthritis of the hip joint. Our group consisted of 17 female and 3 male. In 4 cases the both hip joints were affected. The age of the patients was 26–44 years, average 34 years. The observation period was from 4 months to 6 years, average 2,5 years. The most important clinical symptom was the groin pain on the rest or while flexing the hip joint with internal rotation and adduction. The radiological symptoms in patients before the operation were: decentration, narrowing of the articular space, cysts beyond the sclerotic zone, fatigue fractures of the acetabular edge.

Results. In all the patients, except of one, the pain disappeared. Abduction and internal rotation in the hip joint increased, but flexion decreased. The Wiberg’s angle increased from 10–15° to 25–40°, and the interior Wiberg’s angle from 10–0° to 15–20°. During follow up we observed remodeling of the cysts. The treatment was subjectively assessed by the patients as very good.

Conclusion. The use of the periacetabular osteotomy occording to Ganz is the operation that corrects the hip joint. But in some cases of the osteoarthritis of the hip joint it allows to improve the quality of life and we hope may also delay the arthroplasty in the young age.

Reorientation of the dysplastic acetabulum can be achieved with a simple Salter or Dega osteotomy. While this may be beneficial in children, it is usually insufficient in more severe adolescent or adult dysplasias. Improvement in coverage with double and triple oste-otomies is limited by the size of the acetabular fragment and the ligaments connected to the sacrum. Correction is achieved with the notable asymmetry of the pelvis. The development of these osteotomies results in making the acetabular fragment smaller and smaller and without ligamentous connection between sacrum and sciatic bone. The periacetabular Ganz osteotomy (PAO) is a compromise of the size of acetabular fragment between triple and dial (spherical) osteotomies. The acetabular fragment as in triple Carlioz and Tonnis osteotomies has no connection with the sacrum, what results in enormous possibilities for correction . Finally, the pelvic ring is left untouched.

The aim of the study is to present our experience and early results in using this technique in the treatment of dysplasia with subluxation in adolescent and young adults.

Our material consists of 42 hips in 35 patients (29 females and 6 males) operated in years 1998 – 2001. In 7 cases there was bilateral involvement, the rest were unilateral. The age at operation was between 11 and 39 years, mean 17,5 years. The indication for the PAO in all cases was acetabular dysplasia with different degree of subluxation. In 10 hips there was severe subluxation with CE below 0°, in 4 hips the signs of osteoarthritis were found. The follow-up ranged from 1 to 4 years. Methods. The PAO as a single procedure was done in 39 hips. In only 3 hips the subtrochanteric DVO was done simultaneously. In clinical pre-op. and post-op. examination the following factors were regarded: pain, limping, Trendelenburg sign, range of motion, leg length discrepancy. Radiographic pre-op. and post-op. examination consisted of AP view of the pelvis, false profile and AP view with leg in abduction. Classic and anterior CE angles were measured.

Results. Flexion slightly decreased from pre-op. 90-140° (av.118°) to 80-130° (av.104°) post-op., abduction left unchanged 15-80° (av.40°) and 15-80° (40°) respectively, adduction slightly increased 15-50° (av.31°) and 20-50° (av. 33°). The range of rotation did not change after operation. The sign of Trendelenburg was found in 27 hips pre-op. and in 8 hips post-op. Pain was found in 29 hips before operation and in 4 after surgery. Either classic or anterior CE angle increased after surgery to the normal value in almost all cases from −14° to 34° and from −10° to 35° respectively. We had a rather low complication rate. In our group 35 operations were done without any complications. In 7 hips the following complications were found: in 1 hip overcorrection and in 2 others insufficient correction, 2 urinary infections, ectopic bone formation in 1 hip, local soft tissue infection in 1 hip and in 1 bad scar formation. We did not find any signs of AVN in our series.