We performed a retrospective analysis to evaluate the ability of whole-body . 18. F-fluorodeoxyglucose positron emission tomography (FDG PET) to identify local recurrence and pulmonary metastases in patients with soft-tissue tumours after treatment. We compared the results of FDG PET with those of MRI for the detection of local recurrence, and with CT of the chest for pulmonary metastases. We assessed 62 patients of mean age 51 years, who had 15 types of soft-tissue sarcoma, after a mean follow-up of 3 years 2 months. For the detection of local disease, 71 comparisons showed that the sensitivity and specificity of FDG PET were 73.7% and 94.3%, respectively; there were 14 true-positive and five false-negative results. MRI had a sensitivity and specificity of 88.2% and 96.0% respectively. For the identification of lung metastases, 70 comparisons showed that the sensitivity and specificity of FDG PET were 86.7% and 100%, with 13 true-positive results and two false-negative results. CT of the chest had a sensitivity and specificity of 100% and 96.4%. Thirteen other sites of metastases were identified by FDG PET. FDG PET can identify both local and distant recurrence of tumour as a one-step procedure and will detect other metastases. It seems that all three methods of imaging are needed to define accurately the extent of disease, both at initial staging and during follow-up

The aim of this study was to analyse the gait pattern, muscle force and functional outcome of patients who had undergone replacement of the proximal tibia for tumour and alloplastic reconstruction of the extensor mechanism using the patellar-loop technique.

Between February 1998 and December 2009, we carried out wide local excision of a primary sarcoma of the proximal tibia, proximal tibial replacement and reconstruction of the extensor mechanism using the patellar-loop technique in 18 patients. Of these, nine were available for evaluation after a mean of 11.6 years (0.5 to 21.6). The strength of the knee extensors was measured using an Isobex machine and gait analysis was undertaken in our gait assessment laboratory. Functional outcome was assessed using the American Knee Society (AKS) and Musculoskeletal Tumor Society (MSTS) scores.

The gait pattern of the patients differed in ground contact time, flexion heel strike, maximal flexion loading response and total sagittal plane excursion. The mean maximum active flexion was 91° (30° to 110°). The overall mean extensor lag was 1° (0° to 5°). The mean extensor muscle strength was 25.8% (8.3% to 90.3%) of that in the non-operated leg (p < 0.001). The mean functional scores were 68.7% (43.4% to 83.3%) (MSTS) and 71.1 (30 to 90) (AKS functional score).

In summary, the results show that reconstruction of the extensor mechanism using this technique gives good biomechanical and functional results. The patients’ gait pattern is close to normal, except for a somewhat stiff knee gait pattern. The strength of the extensor mechanism is reduced, but sufficient for walking.

Cite this article: Bone Joint J 2015;97-B:1063–9.