Background Validation of patient-specific surgical guides (PSGs) in pelvic osteotomy has been sporadically reported. The aim of this study was to determine the accuracy of pelvic osteotomy PSG setting, and to validate the effectiveness of PSG in rotational acetabular osteotomy (RAO). Materials and Methods 36 hips in 18 fresh cadaveric samples, including whole pelvis and bilateral lower limbs were used. RAO with PSG was performed in 21 hips (PSG group) while RAO without PSG was performed in other 15 hips (manual group). PSG group was divided into 2 groups; PSG-1 group (osteotomy guide and rotation distance guide use, n=11 hips) and PSG-2 group (osteotomy guide, rotation distance guide, and rotation angle guide use, n=10 hips). The absolute errors between preoperative planning and computed tomography (CT)-based PSG setting (E1), and between preoperative planning and the final procedure (E2) were evaluated using CT in the PSG group. E2 was also evaluated in the manual group as a control. Results E1 was 2.7±1.4° for the abduction angle, 3.9±1.8° for the flexion angle, and 2.1±0.8 mm for the center of the osteotomy sphere in the PSG group. E2 between the preoperative planning and final procedure were smallest in PSG-2 group (manual group / PSG-1 group / PSG-2 group; 5.6±3.2° / 7.2±3.5° / 1.4±1.0° for the abduction angle (p<0.05), 5.8±4.5°/ 6.6±6.2° / 1.8±0.7° for the flexion angle, and 4.8±1.9mm / 4.5±1.2mm / 1.9±1.3mm for the center of the osteotomy sphere (p<0.05)). The accuracy of osteotomy line measured as a distance between the planned sphere surface and the osteotomized bone surface was smaller in PSG group than manual group. Conclusion PSG which regulated osteotomy line, rotational curvature distance, and rotation angle of the bone fragments showed better accuracy in the pelvic osteotomy than the manual procedure.
Sakai et al. (Thu,) studied this question.