Association between union time and clinical and functional outcomes following reconstruction with free vascularized fibular graft in patients with bone tumors.

Abstract

Background: Large segment bone defects resulting from resections done for bone tumors or chronic osteomyelitis may need various treatment options for reconstruction of which use of free vascularized bone grafting is the most commonly used technique due to its ability to maintain biological continuity. In this study, we aimed to investigate the relationship between union time and functional scores in patients who underwent reconstruction with free vascularized fibular grafts (FVFG) for large segment bony defects resulting from resection of bone tumors. Methods: This retrospective study aims to evaluate the clinical outcomes of using free vascularized fibula grafts for the reconstruction of segmental defects following tumor resection at our institution between 2005 and 2021. The tools used for clinical assessment included the Visual Analog Scale (VAS), the Musculoskeletal Tumor Society (MSTS) score, and the Short Form-36 (SF-36) quality of life scale. The relationship between functional outcomes and union time was analyzed retrospectively. The patients were divided into two groups based on union time: those with a union time shorter than 6 months and those with a union time longer than 6 months. The relationship between union time and functional outcomes was analyzed. Additionally, the effects of gender, affected extremity, tumor location, defect size, preoperative and postoperative chemotherapy (CT) and/or radiotherapy (RT) status, presence of distant metastasis, postoperative complications, and hospital stay duration on union time were investigated. Results: A total of 45 patients were included in the study, comprising 20 females and 25 males, with a mean age of 31.3 years (min: 10, max: 74). Seventeen patients had tumors of the upper extremity, while 28 had tumors of the lower extremity. All patients underwent reconstruction of segmental bone defects using free vascularized fibula grafting (FVFG). Preoperative SF-36 quality of life scores were significantly lower when compared to postoperative scores. The patients were categorized into two groups based on union time: those who achieved union within 6 months and those with a union time exceeding 6 months. The analysis demonstrated that patients with upper extremity tumors had a faster union time, while those who experienced postoperative complications had a prolonged union time. Furthermore, extended hospital stays, the presence of preoperative and/or postoperative chemotherapy (CT) and/or radiotherapy (RT), and distant metastasis were associated with lower MSTS scores. However, this decrease in MSTS scores was not statistically significant. Conclusions: Free vascularized fibula grafts are effective biological reconstruction methods that accelerate bone union. The average union time is 6 months, extending up to 9-12 months in some cases. However, by 2 years postoperatively, functional scores are similar, with both mood and extremity function significantly improved compared to preoperative levels.