Injectable synthetic bone graft substitute (GeneX) in the surgical management of benign bone tumours: further experience from a tertiary musculoskeletal oncology centre.

BACKGROUND: Intralesional curettage of benign bone lesions often leaves contained voids requiring augmentation. GeneX (Biocomposites Ltd., Keele, UK) is an injectable synthetic bone graft substitute, comprised of beta-tricalcium phosphate and calcium sulfate, which may simplify postoperative surveillance due to its osteoconductivity and resorption. Evidence for GeneX use in this setting is limited and based mainly on small, heterogeneous series; we report further real-world experience from a tertiary musculoskeletal oncology centre. METHODS: We retrospectively reviewed 21 consecutive patients (mean age, 36 years) who underwent curettage of benign bone tumours and grafting with GeneX between April 2019 and May 2025. The most common tissue diagnoses were enchondroma and aneurysmal bone cysts, and mean preoperative tumour diameter was 31 mm. Primary outcome measures were radiographic incorporation or resorption, complications, restoration of function, and recurrence. RESULTS: Graft resorption was demonstrated in 19 cases (90%) within 3–12 months. In the remaining two patients, resorption could not be confirmed due to limited follow-up imaging and infection requiring graft removal with revision of metalwork, respectively. All patients returned to full weight bearing, most by 6 weeks, and no tumour recurrences were observed during a mean follow-up of 35 months. CONCLUSIONS: In this single-centre cohort, GeneX appeared to be a safe and practical option for filling contained defects following curettage of benign bone tumours, with encouraging radiographic remodelling, timely functional recovery, and no recurrences. These findings supplement the existing literature on synthetic bone graft substitutes in orthopaedic oncology, but require confirmation in controlled comparative studies.