[Clinical Analysis of Surgical treatment of long bone metastases]

To evaluate the safety and efficacy of microwave ablation combined with curettage in the treatment of long bone metastases.

From April 2010 to June 2015, 38 patients with long bone metastases were adopted, who all underwent microwave ablation combined with curettage with 40 lesions involved in Department of Orthopaedic Oncology, Beijing Jishuitan Hospital. There were 22 males and 16 females with an average age of 58.3 years (range from 32 to 83 years). Solitary metastases were found in 9 cases and multiple metastases in 29 patients. Primary malignancies included: 15 cases of lung cancer, 7 cases of renal carcinoma, 4 cases of breast cancer, 3 cases of liver cancer, 1 case of thyroid carcinoma, 1 case of endometrial carcinoma, 1 case of cervical carcinoma, 1 case of esophageal carcinoma and 6 cases of carcinoma of unknown primary. The operative sites included the femur (n=21), the humerus (n=12) and the tibia (n=7). There were 23 cases of pathologic fractures which included: 12 in femur, 10 in humerus and 1 in tibia. Curettage after in situ microwave ablation was performed in 40 lesions. Reconstructions were carried out in all lesions: bone cement filling alone in 1 lesion and bone cement filling with metal implants in the other 39 lesions.

The mean follow-up was 6.9 months (range; 1-65 months). During the follow-up, 22 patients died and 16 patients were alive. The 6-month overall survival (OS) was 73.7%, and the 1-year and 2-year OS were 48.6% and 28.1% respectively. The postoperative survival time was 7.1 months on average (range 2-40 months) in the 22 patients who finally died. The occurrence of pathological fracture had a significant effect on the OS (χ(2)=5.606, P=0.018). The local recurrence rate was 10% (4/40), which occurred at 6.8 months after the operation on average (range 2-14 months). No complications occurred in the perioperative period, and there were no complications such as internal fixation failure or pathological fracture noticed during the follow-up period. The scores of VAS, KPS and ECOG were significantly improved after operation. The mean MSTS score was 22 points (range 17-28 points) in 33 evaluable locations and the rate of excellent and good was 72.7%.

Microwave ablation combined with curettage appears to be a safe and effective approach in the surgical treatment of long bone metastases, which can relieve local pain and control the local development of bone metastases.