We evaluated the oncological and functional outcome of 18 patients, whose malignant bone tumours were excised with the assistance of navigation, and who were followed up for more than three years. There were 11 men and seven women, with a mean age of 31.8 years (10 to 57). There were ten operations on the pelvic ring and eight joint-preserving limb salvage procedures. The resection margins were free of tumour in all specimens. The tumours, which were stage IIB in all patients, included osteosarcoma, high-grade chondrosarcoma, Ewing's sarcoma, malignant fibrous histiocytoma of bone, and adamantinoma. The overall three-year survival rate of the 18 patients was 88.9% (95% confidence interval (CI) 75.4 to 100). The three-year survival rate of the patients with pelvic malignancy was 80.0% (95% CI 55.3 to 100), and of the patients with metaphyseal malignancy was 100%. The event-free survival was 66.7% (95% CI 44.9 to 88.5). Local recurrence occurred in two patients, both of whom had a pelvic malignancy. The mean Musculoskeletal Tumor Society functional score was 26.9 points at a mean follow-up of 48.2 months (22 to 79). We suggest that navigation can be helpful during surgery for musculoskeletal tumours; it can maximise the accuracy of resection and minimise the unnecessary sacrifice of normal tissue by providing precise intra-operative three-dimensional radiological information.

Open surgery is rarely justified for the initial treatment of a unicameral bone cyst, but there is some debate concerning the relative effectiveness of closed methods. This study compared the results of steroid injection with those of autologous bone marrow grafting for the treatment of unicameral bone cysts. Between 1990 and 2001, 30 patients were treated by steroid injection and 28 by grafting with autologous bone marrow. The overall success rates were 86.7% and 92.0%, respectively (p>0.05). The success rate after the initial procedure was 23.3% in the steroid group and 52.0% in those receiving autologous bone marrow (p<0.05), and the respective cumulative success rates after second injections were 63.3% and 80.0% (p>0.05). The mean number of procedures required was 2.19 (1 to 5) and 1.57 (1 to 3) (p<0.05), the mean interval to healing was 12.5 months (4 to 32) and 14.3 months (7 to 36) (p>0.05), and the rate of recurrence after the initial procedure was 41.7% and 13.3% in the steroid and in the autologous bone marrow groups, respectively (p<0.05). Although the overall rates of success of both methods were similar, the steroid group had higher recurrence after a single procedure and required more injections to achieve healing.

Our data suggest that intercalary allograft has better survival and fewer complications than the low-heat treated autograft.

PMS in osteosarcoma patients was influenced by primary tumor-related factors such as histologic response to chemotherapy, as well as metastasis-related factors such as complete metastasectomy and metastasis site. A certain group of patients without such poor prognostic factors could be cured even after the development of metastasis.

Osteochondral defect in the posterolateral aspect of the capitellum is an important indicator of PLRI; however, the result of this study suggests ligament reconstruction for those with a large bone defect may not be always successful.