Background: Bone metastases represent the most frequent cause of cancer-related pain, affecting health-related quality of life and creating a substantial burden on the healthcare system. Although most bony metastatic lesions can be managed nonoperatively, surgical management can help patients reduce severe pain, avoid impending fracture, and stabilize pathologic fractures. Studies have demonstrated functional improvement postoperatively as early as 6 weeks, but little data exist on the temporal progress of these improvements or on the changes in quality of life over time as a result of surgical intervention., Questions/purposes: (1) Do patients' functional outcomes, pain, and quality of life improve after surgery for long bone metastases? (2) What is the temporal progress of these changes to 1 year after surgery or death? (3) What is the overall and 30-day rate of complications after surgery for long bone metastases? (4) What are the oncologic outcomes including overall survival and local disease recurrence for this patient population?, Methods: A multicenter, prospective study from three orthopaedic oncology centers in Quebec, Canada, was conducted between 2008 and 2016 to examine the improvement in function and quality of life after surgery for patients with long bone metastases. During this time, 184 patients out of a total of 210 patients evaluated during this period were enrolled; of those, 141 (77%) had complete followup at a minimum of 2 weeks (mean, 23 weeks; range, 2-52 weeks) or until death, whereas another 35 (19%) were lost to followup but were not known to have died before the minimum followup interval was achieved. Pathologic fracture was present in 34% (48 of 141) of patients. The median Mirel's score for those who underwent prophylactic surgery was 10 (interquartile range, 10-11). Surgical procedures included intramedullary nailing (55), endoprosthetic replacement (49), plate osteosynthesis (31), extended intralesional curettage (four), and allograft reconstruction (two). Seventy-seven percent (108 of 141) of patients received radiotherapy. The Musculoskeletal Tumor Society (MSTS), Toronto Extremity Salvage Score (TESS), Brief Pain Inventory (BPI) form, and Quality Of Life During Serious Illness (QOLLTI-P) form were administered pre- and postoperatively at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year. Analysis of variance followed by post hoc analysis was conducted to test for significance between pre- and postoperative scores. The Kaplan-Meier estimate was used to calculate overall survivorship and local recurrence-free survival. A p value of < 0.05 was considered statistically significant., Results: MSTS and BPI pain scores improved at 2 weeks when compared with preoperative scores (MSTS: 39% ± 24% pre- versus 62% ± 19% postoperative, mean difference [MD] 23, 95% confidence interval [CI], 16-32, p < 0.001; BPI: 52% ± 21% pre- versus 30% ± 21% postoperative, MD 22, 95% CI, 16-32, p < 0.001). Continuous and incremental improvement in TESS, MSTS, and BPI scores was observed temporally at 6 weeks, 3 months, 6 months, and 1 year; for example, the TESS score improved from 44% ± 24% to 73% ± 21% (MD 29, p < 0.001, 95% CI, 19-38) at 6 months. We did not detect a difference in quality of life as measured by the QOLLTI-P score (6 ± 1 pre- versus 7 ± 4 postoperative, MD 1, 95% CI, -0.4 to 3, p = 0.2). The overall and 30-day rates of systemic complications were 35% (49 of 141) and 14% (20 of 141), respectively. The Kaplan-Meier estimates for overall survival were 70% (95% CI, 62.4-78) at 6 months and 41% (95% CI, 33-49) at 1 year. Local recurrence-free survival was 17 weeks (95% CI, 11-24)., Conclusions: Surgical management of metastatic long bone disease substantially improves patients' functional outcome and pain as early as 2 weeks postoperatively and should be considered for impending or pathologic fracture in patients whose survival is expected to be longer than 2 weeks provided that there are no immediate contraindications. Quality of life in this patient population did not improve, which may be a function of patient selection, concomitant chemoradiotherapy regimens, disease progression, or terminal illness, and this merits further investigation., Level of Evidence: Level II, therapeutic study.