Clinical and radiological results of allogenous bone graft versus synthetic calcium‐phosphate graft in opening wedge high tibial osteotomy

Abstract Purpose To compare the clinical and radiographic data after opening wedge high tibial osteotomy (OWHTO) using an allogenous bone graft versus a tricalcium phosphate (TCP) graft. Methods This prospective clinical study enroled 42 patients (84 knees) between September 2022 and March 2023, undergoing bilateral OWHTO for genu varum. Patients' knees were randomized intraoperatively into two groups: those receiving an allograft or TCP graft to fill the osteotomy defect. Preoperative assessments included pain severity via the visual analogue scale (VAS) and joint function using the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). The osteotomy was corrected using the Minami–Miniaci method, and stabilization was achieved with a fixed‐angle locking plate. Pain, complications and radiographic outcomes were monitored post‐operatively, with bone union assessed via the Hemert criteria. Results In this cohort of 42 patients (59.5% male, mean age 36.6 ± 5.0 years), all non‐smokers, the mean follow‐up was 2.1 years. Pre‐ and post‐operative comparison using WOMAC (pre‐op = 16.1 ± 8.4; post‐op = allograft: 11.3 ± 4.7, p = 0.00; TCP = 9.3 ± 4.8, p = 0.00) and VAS scores (pre‐op = 2.8 ± 0.9; post‐op = allograft: 2.2 ± 0.8, p = 0.00; TCP = 1.8 ± 1.2, p = 0.00) revealed statistically and clinically significant outcomes. In WOMAC components meaningful pain (pre‐op = 4.4 ± 1.7; post‐op = allograft: 2.9 ± 1.3, p = 0.00; TCP = 2.4 ± 1.4, p = 0.00), stiffness (pre‐op = 1.7 ± 1.2; TCP = 1.3 ± 1.1, p = 0.01) and physical function (pre‐op = 9.9 ± 7.1; post‐op = allograft: 7.7 ± 3.9, p = 0.00; TCP = 6.4 ± 4.0, p = 0.00) improvements at 12 months in both grafts, except stiffness in allograft group (pre‐op = 1.7 ± 1.2 post‐op = allograft: 1.6 ± 1.2, p = 0.08). However, post‐operative analysis revealed that the TCP graft showed statistically significant superiority in WOMAC and VAS scores ( p < 0.05), except pain component of WOMAC (TCP = 2.4 ± 1.4, allograft = 2.9 ± 1.3, p = 0.305). Bone consolidation occurred in 54.8% of cases. No intraoperative complications, infections or loss of correction were reported during follow‐up. Conclusions Patients undergoing OWHTO with TCP granules experienced better outcomes and less pain, compared to those receiving allogeneic bone grafts. Level of Evidence N/A.