The morphology of the sacral corridor for transiliac transsacral screw in Japanese osteoporotic vertebral fracture patients: Analysis using CT data.

[Introduction] Fragility fractures of the pelvic ring are increasing in the elderly population. A percutaneous sacroiliac screw is one of the methods used to fix of the posterior pelvic element with less dislocation. It is advantageous for elderly because minimally invasive insertion is possible; although there are few reports studying the Japanese population. Here, we investigated the Japanese sacral morphology and examined the feasibility of the percutaneous transiliac transsacral screw method. [Materials and Method] Seventy patients with osteoporotic vertebral fractures were included. For the measurement, CT images were analyzed using Zedhip (LEXI) based on the method of Goetzen. The column between S1 and S2 was classified into three groups, the ascending type, horizontal type, descending type, and the presence or absence of a notch was investigated. [Result] There were many ascending types in the center of S1, a few descending types, and many patients with a notch in the S2. There were many ascending types in middle of the S1 and many patients with a notch in middle of the S2 and lower quarter. [Conclusion] There is a tendency that indicates TITS screw penetration may be difficult in the S1, and it is necessary to consider the possibility of insertion via preoperative CT planning. Adaptation of the percutaneous TITS screw fixation technique for the Japanese elderly population with osteoporotic vertebral fractures should be carefully considered.