The purpose of this study is to present early results, common pitfalls and management in in cases of revision hip arthroplsty in patients with congenital disease of the hip.

From 2001 to 2006, 36 consecutive cemented THAs with a history of congenital hip disease were revised due to aseptic loosening (31 cases), stem fracture (3 cases), septic loosening (2 case). There were thirty patients, all females, with a mean age at revision 61.7 years (range, 40 to 76). The revision was performed after a mean 15.4 years post primary operation (range, 9 to 26). In 7 cases the cup only, in 5 cases the stem only, and in 24 cases both components were revised.

The mean follow-up was 43 months (range, 24 to 84). There were 3 intraoperative femoral fractures managed with long stem and circlage wires. Postoperatively, 5 hips were infected and sustained a 2 stage revision using a cement spacer. 3 hips were revised due to loosening.

28 cups and 28 stems remained intact for an average 45.2 months (range, 24 to 84). The probability of survival at 48 months was 76.3% (±9.7%) for the cups (12 components at risk) and 76.4% (±11.3%) for the stems (9 components at risk).

Revision of a CDH arthroplasty is difficult and non predictable. Lack of acetabular bone stock and anatomical abnormalities of the femur lead to increased intra and postoperative complication rate.

Aim: The aim of the study is to evaluate the results of the use of the Rotating Knee Endo Model not only as a revision implant, but as a primary choice too.

Method: It is a retrospective study of 73 patients who underwent primary total knee replacement (TKR) in 96 knees, during 1990–2001. The mean follow up is 5.6 years. The average age of the patients was 70.6 years (38 – 87 years), and 79.6 % were female. The indications for surgery were osteoarthritis in 66 knees, rheumatoid arthritis (R.A.) in 10 knees and aseptic osteonecrosis of femoral condyles in 3 knees. Seventy-nine prosthesis were examined both clinically and with plain films. Fifteen patients died in the mean time and 2 others could not participate in the follow up. The pre- and post-operative evaluation based on the «The Hospital for Special Surgery (HSS) knee rating scale».

Results: Fifty-eight knees were rated as excellent, 13 knees were rated as good and 8 knees were rated as fair. Deep venous thrombosis occured in 3 patients, non-fatal pulmonary embolism in 2, and 3 patients demonstrated superficial wound infection cured with oral antibiotic administration. One patient suffered dislocation of the apparatus, which required revision of the femoral component. The tibial insertion of the patellar tendon of one patient detached, which was reattached. Ectopic ossification was present in another patient 4 months after surgery and excised in a second stage, deep infection in 1 patient with history of osteomyelitis silent for 10 years, who eventually underwent an above-knee amputation.

Conclusions: The Rotating Knee Endo Model allows axial correction of the extremity, stabilization of the joint, useful range of motion and pain relief while the infection rate is considered low. So the prosthesis could be a good alternative not only in revision procedures but in primary TKA in cases of serious axial deformity and in rheumatoid knees with instability and muscular atrophy as well.