Factors Influencing Nonunion and Fracture Following Biological Intercalary Reconstruction for Lower‐Extremity Bone Tumors: A Systematic Review and Pooled Analysis

OBJECTIVES: To determine nonunion rate, fracture rate, and their risk factors following biological intercalary reconstruction for lower extremity bone tumors. METHODS: A systematic review and pooled analysis were conducted. PubMed, Embase, and Wiley Cochrane Library were searched from inception up to June 01, 2020. Studies concerning biological intercalary reconstruction after resection of lower extremity bone tumors were included. Overall nonunion and fracture rates were calculated. For studies reporting patient outcomes individually with precise graft characteristics and fixation methods, the individual data were extracted. Patients with demographical and clinical characteristics, including age, sex, tumor location, graft characteristics, and fixation method, were pooled for a multivariate analysis. For each factor of interest, odds ratio (OR), 95% confidence interval (95% CI), and p‐value from logistic regression were reported. RESULTS: A total of 2776 articles were identified from the initial literature search and 76 studies (2052 patients) were included. Sixty‐nine studies were case series and seven were comparative studies. The overall nonunion rate was 19% (382/2052; range: 0%–53%), and the overall fracture rate was 17% (344/2052; range: 0%–75%). Thirty of the 76 studies (362 patients) reported patients' characteristics individually and were thus included in the pooled multivariate analysis. Intramedullary nail fixation was associated with a significantly higher nonunion rate compared to plate fixation (OR = 2.2, 95% CI: 1.23–4.10, p = 0.009). Reconstruction with a vascularized fibula graft had a statistically non‐significant lower nonunion rate than reconstruction without the graft (OR = 0.6, 95% CI: 0.34–1.07, p = 0.086). Devitalized autografts had a lower fracture risk than allografts (OR = 0.3, 95% CI: 0.14–0.64, p = 0.002), and males tended to have higher fracture risk than females (OR = 2.1, 95% CI: 1.00–4.44, p = 0.049). CONCLUSIONS: Reconstruction with intramedullary nail fixation is related to an elevated risk of nonunion. Allografts and males have a higher fracture risk than devitalized autografts and females, respectively. Further high‐quality comparative analyses with large sample sizes and adequate follow‐up duration are needed to validate these findings.