Aim

To compare the rate and severity of avascular necrosis following medial open and closed reduction in developmental hip dysplasia and the resulting influence on femoral and acetabular development.

In conventional high tibial osteotomy it is difficult to obtain the ideal correction angle consistently and there is high variability of postoperative alignment. We assessed the reliability, accuracy and variability of closed wedge high tibial osteotomy using computer-assisted surgery compared to the conventional technique. Fifty closed wedge HTO procedures were performed and analysed between July 2005 and July 2006, using the CT-free navigation system(Vector Vision^® version 1.1, Brain-LAB, Heimstetten, Germany) for medial compartment osteoarthritis of the knee and fifty knee operations using conventional closed-wedge HTO, performed between 1994 and 2006, were retrospectively reviewed as a control group. The mean age was 59.4 years for the navigation group and 60.7 years for the conventional group. In the navigation group, the mean mechanical axis (MA) before osteotomy was varus 8.2°, and the mean MA after the fixation was valgus 3.6°. On the radiographs, the mean preoperative MA was varus 7.3°, and the mean postoperative MA was valgus 2.1°. In the conventional group, the mean MA was varus 10.6° preoperatively and valgus 0.1° postoperatively via the radiograph. The mean preoperative posterior slope angle (PSA) was 11.0°, which decreased to 9.0° in the navigation group. The mean preoperative PSA was 10.4°, which decreased to 6.4° in the conventional group(p = 0.000). There was a positive correlation between measured data taken under navigation and by radiographs(r > 0.3, P < 0.05). The mean correction angle was significantly more accurate in the navigation group(p < 0.002). The variability of the correction was significantly lower in the navigation group (2.3° versus 3.7°, p = 0.012), and the distribution of MA was also narrower in the navigated group.

We concluded that navigation provides reliable real-time intraoperative information and may increase accuracy, and improve the precision of closed-wedge HTO.

There is quite a high incidence of musculoskeletal disorders in the hemophiliac patients because of their insufficiency in blood coagulation. Knee joint disability is the most troublesome problem among the all. Repeated bruise and intra-articular hemorrhage may activate hypertrophic synovitis and progress to advanced arthritis. The characteristic clinical presentation is their fusiform limbs with moderate degree of contracture and deformity. Treatments include administration of specific coagulation factors, aspiration of hemarthrosis and proper bracing. Synovectomy will treat and retard the progression of the disease, while some advanced cases may end up to spontaneous fusion or need surgical arthrodesis. Total knee arthroplasty is another option for such a knee problem in hemophiliac patients.

We have done 26 total knee arthroplasties in 19 hemophiliac patients since 1986. Male is predominant with sex-linked inheritance with only one exception. The timing for them to have surgery is from 22 to 47 years old with mean age of 30. Gross patholgies of the knee lesion are quite universal as hypertrophy of hemosiderin deposited synovium, destruction of articular catilage, subchondral bone loss, marginal osteophytes formation, fibrous contracture around the joints. Two cases were excluded for other systemic disease.

With the help of supplementary coagulation factor, the surgical courses were rather smooth with one exception of septic shock episode. There were no infections in total series but three revisions of prosthesis were done because of loosening or malposition. All the patients were satisfied with the improvement of function score and range of knee motion. Total knee arthroplasty did a great success for the relief of pain and function for such a knee disorder. The only remained troublesome problem is the extremely high cost of the coagulation factor therapy which may be an economic shock to the patients.