Total 98 62 34–88 Males Females 46 60 43–88 52 63 34–84 21 20 5 25 8 4 3 3 3 18 24 2 2 10 11 12 12 1 24 10 5 28 26 21 5 33 6 4 4 3 2 28 7 14 6 24 21 5 3 2 28 17 7 31 Acta Orthopaedica 2011; 82 (1): 96–101 Table 1. 98 lung cancer patients with skeletal metastases Number of patients Median age at diagnosis (years) range Smoking status at diagnosis Former smoker Current smoker Never smoker Histopathology Non-small cell cancer Adenocarcinoma Squamous cell carcinoma Low differentiated non-small cell cancer Large cell carcinoma Small cell cancer Other cancers Skeletal metastasis Femur Vertebra Humerus Other Type of surgical procedure Internal fixation Endoprosthesis Spinal decompression + instrumentation Spinal decompression Other Preoperative treatment (primary tumor) Chemotherapy Radiotherapy Lobectomy Postoperative treatment (bone metastasis) Radiotherapy 47 41 10 58 14 8 7 6 5 46 31 16 8 34 32 17 15 3 52 27 12 59 (Mountain 1997). Neurological function in patients with spinal metastases is assessed by the Frankel classification of motor and sensory compromise (Frankel et al. 1969, Davis et al. 1993). The neurological function is assessed preoperatively and within 2 weeks postoperatively. For the present study, we included all lung cancer patients who had surgery due to pathological fractures. None of the patients were excluded for any reason. In patients who had surgery for more than 1 metastasis, all sites were included in the analysis. However, only the first surgical procedure was accounted for in the survival analysis. The study period was 1987–2006. We identified 98 individual lung cancer patients (52 females) treated surgically for skeletal metastatic lesions. The median age at surgery was 62 (34–88) years. Most patients in this cohort (n = 88) were current or former smokers at diagnosis of the disease. Adenocarcinoma was found in most cases (n = 58) followed by squamous cell carcinoma (n = 14) (Table 1). The lung cancer patients were grouped in the following stages: 11 IA + IB, 1 IIA + IIB, 5 IIIA, 73 IIIB + IV, and such data were missing for 8 patients. 97 Statistics Median values and ranges were used as descriptive statistics. Kaplan-Meier analysis was used to construct the cumula- tive survival with 95% confidence intervals (CIs). The time between diagnosis of lung cancer and death and time between surgical procedure and death were included in the survival analysis. The log-rank test was used to compare survival after extremity surgery with spine surgery. The Cox multiple-regression model was used to study risk factors for death related to the patient and to the surgical pro- cedure. The results were expressed as hazard ratios (HRs) with corresponding 95% CI. If a HR was > 1, the patients at risk were dying at a faster rate than the patients in the reference group. The assumption of proportional hazards was investi- gated by hazard function plots and log-log plots for all covari- ates. No signs of insufficient proportionality were detected in the hazard functions and the log-log plots ran parallel for all covariates. The factors studied in the univariate Cox model were as follows: age, sex, smoking status, type of lung cancer, staging, location of skeletal metastasis, type of pathological fracture, preoperative hemoglobin levels, time period of sur- gery (1987–1996 vs. 1997–2006) and perioperative chemo- and radiotherapy (Table 1). Any variable whose univariate test had a p-value of < 0.25 was considered as a candidate for the multivariate model along with all variables of known biologi- cal importance. Wilcoxon’s signed ranks test was used to com- pare preoperative and postoperative neurological function in patients with spine metastases. The level of significance was set at p ≤ 0.05. All statistical analyses were performed using the PASW statistics package version 18 (SPSS Inc., Chicago, IL). Results Most metastatic bone lesions were located in the femur and vertebra. Of the 31 vertebral lesions, 22 were located in the thoracic spine and 9 in the lumbar spine. 53 of 70 non-spinal lesions had caused complete pathological fractures. Regarding treatment of the primary tumor, more than half of the patients (n = 52) had chemotherapy and 27 had radiotherapy. Postop- erative radiotherapy for the operated lesions was registered in 59 patients (Table 1). None of the patients were lost to follow- up, and none were still alive at the time of this analysis. The neurological function in patients with spine metasta- ses improved after surgery (p = 0.001). 16 of the 31 patients gained at least 1 Frankel grade, 14 maintained their neurologi- cal function, and 1 patient deteriorated (Table 2). The main indication for surgery in these patients was spinal cord com- pression (n = 29) or painful instability (n = 2). Survival analysis The median survival time after surgery of skeletal metastatic lesions was 3 (0–127) months. Males had a median survival