Preliminary results of the use of bone substitute material “Rekost” in surgical treatment of bone tumors

Backgtound. Replacement of large bone defects after tumor resection is a significant challenge. The use of autologous tissue is often limited due to the small volume of available autograft bone and additional surgical trauma. Although many biological and synthetic substitutes exist, there is still no consensus on the optimal choice. Recost, a new domestic synthetic bone substitute material, introduced in 2014, is a promising alternative for reconstructive surgery. the purpose of the study was to analyze outcomes of using “Rekost”, the bone substitute material, in surgical treatment of bone tumors. Material and Methods. Between 2016 and 2022, 23 patients with bone tumors were treated at the oncology department of the E. Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation. The study included patients over 18 years of age with benign and tumor-like bone neoplasms (11/23, 47.8 %), as well as patients with borderline bone tumors (11/23, 47.8 %), who underwent surgery with the simultaneous use of Recost, a new bone-substituting material. One patient had osteosarcoma (1/23, 4.3 %). Most patients (20/23, 86.9 %) underwent bone tumor resection followed by reconstruction with “Rekost” bone-replacing material. Results. All patients are alive with follow-up periods ranging from 30 to 113 months (mean 62 ± 7). Early postoperative pain, assessed by the Visual Analog Scale (VAS), ranged from 10 % to 50 %, averaging 20 ± 10 %. At 12 months postoperatively, most patients were free of pain (0–20 %). Functional outcomes measured by the Musculoskeletal Tumor Society (MSTS) score were rated as excellent or good on follow-up: upper limb MSTS scores ranged from 73 to 97 %, mean 89 ± 10 %; lower limb MSTS scores ranged from 57 % to 100 %, mean 81 ± 14 %. No intraoperative, early postoperative, or systemic complications related to the use of “Rekost” material were observed. Late local complications occurred in two cases (2/23; 8.6 %) at 6 and 9 months postoperatively. Among patients with borderline tumors, one patient (1/11, 9 %) developed giant cell tumor recurrence nine months after resection of the distal radius. One-and two-year recurrence-free survival rates in this subgroup of patients were 92 %, respectively. Conclusion. Preliminary use of the “Rekost”, domestic bone substitute demonstrates a low rate of complications and re-surgeries. This material may be recommended for reconstructing defects after tumor resections in patients with benign and borderline bone tumors. However, the physical and chemical properties of the material require further study and comparative analysis with traditional reconstruction methods.