Autologous bone block grafting reduces the incidence of delayed union of the pubic osteotomy site at one year after curved periacetabular osteotomy

Abstract Curved periacetabular osteotomy (CPO) requires a pubic osteotomy. One of the complications after CPO is delayed union of the pubic osteotomy site, which contributes to persistent pain. We investigated the effect of autologous bone block grafting on the rate of delayed union of the pubic osteotomy site. This retrospective study included 12 hips in 12 patients who underwent CPO with autologous bone block grafting (bone block grafting group) between October 2021 and April 2023, and 49 hips in 45 patients who underwent CPO without bone block grafting (control group) between July 2017 and August 2019. A medical chart review was conducted to extract patient demographics, surgical details, clinical scores, and smoking history. Radiological parameters and the gap width at the pubic osteotomy site were measured on 1-week-post-operative computed tomography (CT) scans, and bone union at the pubic osteotomy site was measured on 1-year-post-operative CT scans. Variables were compared between groups. The two groups had no significant differences in demographic characteristics. Compared with the control group, the bone block grafting group had a significantly higher rate of union at the pubic osteotomy site and a significantly shorter gap width of the pubic osteotomy site. The two groups had no significant differences in the operation time, peri-operative blood loss, and pre- and post-operative clinical scores and radiographic data. Autologous bone block grafting at the pubic osteotomy site significantly improved the bone union rate at 1 year post-operatively compared with the conventional procedure without grafting.