Acta orthopaedica Scandinavica. Supplementum最新文献

Initial stability is necessary for permanent fixation of acetabular cups. Biologic reactions to submicron particles such as localized bone resorption may lead to implant failure. The aim of the study was to evaluate different fixation principles of acetabular components. Four randomized studies and one case-control study were performed to evaluate different bone cements, different cup designs, use of ceramic coating or not, different type of screws and the need of additional screw fixation or not. Radiostereometry (RSA) makes it possible to analyze small translations and rotations of implants with a high accuracy. This method is suitable for evaluation of early stability and was used in four of the studies. Clinical and radiological follow-up were performed regularly. The cements were tested in the laboratory. 30 patients (mean age 71 years, range: 63-76) received total hip arthroplasties and were randomised to fixation with Boneloc (14) or Palacos cum gentamicin (16) bone cement. The curing temperature was 23 degrees lower for the Boneloc cement but the tensile strength was reduced and the elastic modulus was lower compared to Palacos. The proximal cup migration was greater in the Boneloc group up to 12 months (p 0.04) and these cups migrated medially in contrast to a small lateral migration seen in the Palacos group (p 0.04). Radiolucencies were more pronounced in the Boneloc group at 12 months (p 0.04). 155 patients (171 hips, mean age 50 years, range: 24-64) received uncemented hip arthroplasties. 84 hips were randomised to the PCA and 87 to the Harris-Galante I designs. The 10-year survival rates were 85% for the PCA and 99% for the Harris-Galante I cups (revision as end-point). The wear and clinical results did not differ. 43 patients (mean age 60 years, range 44-68) received uncemented porous cups with a titanium mesh in pure titanium (Harris-Galante II) and were randomised to additional fixation with either biodegradable screws (23, poly-L-lactic acid, PLLA) or screws made of titanium alloy (20). Increased proximal and medial-lateral translations (p 0.02, 0.04) but less rotation around the longitudinal axis (p 0.04) were seen in the PLLA group up to 2 years. There were also more pronounced radiolucencies anteriorly in this group at 2 years. The clinical results did not differ. 23 uncemented porous cups (Harris-Galante II) with hydroxyapatite-tricalciumphosphate coating (HA/TCP) were pair-wise matched to uncoated cups. Up to 2 years, decreased rotations around the horizontal axis were recorded in the HA/TCP-coated cups. Central postoperative gaps were more frequently seen in the HA/TCP group (p < 0.01), but at 2 years radiolucencies were more pronounced in the uncoated group (p < 0.01). The wear and clinical results did not differ. 62 patients (64 hips, mean age 56 years, range: 32-75) were randomized to porous Trilogy cups with (30) and without (34) cluster holes for additional screw fixation. Up to 2 years there were no differences

114 patients with osteosarcoma in the extremities had been reported to the SSG II trial, 132 to the SSG VIII trial and, until October 1998, 99 to the ISG/SSG I trial. The SSG IV trial included 53 patients and the SSG IX trial 104 patients until October 1998. In the SSG II trial, 19% were good responders (grades III and IV) as compared to 51% in the SSG VIII trial. On reevaluation was the response changed in one forth of the cases in both the SSG II and SSG VIII trials. In 9 and 10 cases (8%), respectively, the reevaluation resulted in a change from "good responder" to "bad responder". In the ISG/SSG I trial, the preliminary results showed a good response in 22% of the cases. In the SSG IV trial, 44% were good responders (grades III and IV), as compared to 54% in the SSG IX trial.

In the present multicenter study from the Scandinavian Sarcoma Group, local recurrence was analyzed regarding a change in the chemotherapy protocol and an increasing number of limb-salvage procedures 1982-97. Surgery was performed at 13 hospitals in Scandinavia. We analyzed the data of 223 patients with non-metastatic, high-grade osteosarcoma of the extremities, treated according to the SSG II and VIII protocols. The rate of limb-salvage surgery was 0.3 in SSG II, as compared to 0.6 in SSG VIII. The local recurrence rates of the limb-salvage patients were 10% (SSG II) and 11% (SSG VIII), as compared to 4% and 2%, respectively, among the amputated patients. We found no significant difference in outcome i.e., in local recurrence and survival rate despite an increased rate of good responders in SSG VIII, as compared to SSG II. It may be shown that the continuously increasing use of limb-salvage surgery is associated with a higher rate of local recurrence than with ablative surgery, despite better chemotherapy.

During the past 15 years the Scandinavian Sarcoma Group has treated 140 patients with Ewing's sarcoma. Two protocols have been used. SSG IV included 52 patients between 1984 and 1990 and SSG IX, 88 patients since 1990. After 5 years of treatment, local recurrences occurred in 19% of the patients (M0 + M1) in the SSG IV group and 10% in the SSG IX group. Distant metastases developed in 57% of the M0-patients in the SSG IV group and in 33% in the SSG IX group. Tumor-related survival (overall) of M0-patients was 49% in SSG IV and 70% in SSG IX, and the metastasis-free survival rate 45% and 58%, respectively. Patients having a localized extremity tumor had a survival rate of 90% (SSG IX). In both treatment groups, good responders to chemotherapy had a better survival rate than poor ones (SSG IV, p < 0.02, GI-II vs. G II-IV and SSG IX, p < 0.003, GI-III vs. G IV). In conclusions local control and survival rates were better with SSG IX than SSG IV.