Surgical treatment of benign bone tumors in the pelvic region is technically challenging. Traditional cortical fenestration methods rely heavily on the surgeon's experience, making it difficult to consistently control the position and extent of the bone window. This study reports the design of a 3D-printed fenestrated guide and evaluates its ability to control fenestration dimensions and its preliminary clinical outcomes in intralesional curettage of benign pelvic bone tumors.

This retrospective study included six patients with benign or locally aggressive pelvic bone tumors who underwent intralesional curettage assisted by an individualized 3D-printed fenestrated guide between January 2022 and August 2024. The guide was designed from preoperative CT data to conform to the local bony contours and assist intraoperative localization and cortical fenestration of the planned bone window. The primary outcome was the dimensional consistency between the intraoperative bone flap and the planned guide fenestration (bone-contacting side, projected onto the cortical bone surface). Secondary outcomes included perioperative parameters, MSTS-93 functional scores, complications, and radiographic follow-up.

All surgeries were completed successfully with guide assistance. The achieved bone flap dimensions closely matched those of the planned guide fenestration: median long-axis deviation −1.65 mm (range, −2.8 to +2.4) and median short-axis deviation −0.90 mm (range, −1.8 to +1.5). All deviations fell within ±3 mm. The median operative time was 150 min (range, 130–170) and the median intraoperative blood loss was 200 mL (range, 100–300). At a median follow-up of 25 months (range, 20–34), all patients showed satisfactory bone window healing with no local recurrence. The median MSTS-93 score increased from 26 (87%) at 3 months to 28.5 (95%) at final follow-up (   ). One patient developed a Clavien–Dindo grade IIIb infection that resolved after debridement and antibiotic therapy.

The 3D-printed fenestrated guide may assist intraoperative localization and controlled cortical fenestration in selected benign pelvic bone tumors.