骶髂关节螺钉固定应用及CT与解剖学研究

目的 :采用CT扫描测量髂骨翼后外侧面至第 1骶椎 (S1)的距离和S1椎弓根宽 ,为临床上经骶髂关节螺钉固定治疗后骨盆环不稳定提供参考。方法 :对 2 2例中国成人的骨盆标本共 4 4侧骶髂关节进行CT和解剖学研究 ,测量S1椎弓根宽 ,髂骨翼后外侧面的进针点至S1椎弓根中心距离 ,进针点至S1椎体对侧前皮质距离 ,并对解剖测量值和CT测量值进行比较。在实验研究的基础上 ,对 11例垂直不稳定后骨盆环骨折进行骶髂螺钉固定。结果 :髂骨翼后外侧面的进针点至椎弓根中心距离解剖和CT测量值分别为 4 9 5± 4 0mm和 4 9 2± 3 9mm ,两者差异无显著性 (P >0 0 5 ) ;进针点至S1椎体对侧前皮质距离解剖和CT测量值分别为 86 9± 4 6mm和 86 4± 4 4mm ,两者差异无显著性 (P >0 0 5 ) ;S1椎弓根宽解剖和CT测量值分别为 2 7 7± 2 0mm和 2 0 7± 2 5mm ,两者差异有显著性 (P <0 0 1)。临床 11例共 13枚骶髂螺钉均准确置入 ,无骨皮质穿破或神经血管损伤等并发症。结论 :术前CT扫描可准确地推算骶髂螺钉长度 ,具有临床实用意义。

Anatomical and computer tomographical study of the lag screw fixation of the sacroiliac joint

Objective:To measure the distance from entry point on the posterolateral ilium to the first sacral vertebra(S₁)and the width of pedicle of S₁,according to computer tomographical scan.Methods:22 pelvis specimens of native adults were studied,for a total of 44 sacroiliac joint.Spiral computer tomography was used to scan 22 pelvis specimens.The distance from entry point on the posterolateral ilium to the center of pedicle of S₁,the distance from entry point to contrary anterior cortex of S₁ and the width of pedicle of S₁ were measured on axial computer tomography scans.Then,anatomical measurement were performed on 22 cadaveric pelvis to determine the distance from enrty point on the posterolateral ilium to the center of pedicle of S₁,the distance from entry point to contrary anterior cortex of S₁ and the broad of pedicle of S₁.11 patients with unstable posterior pelvic fractures were treated with iliosacral screw on the basis of this study.Results:The distance from entry point on the posterolateral ilium to contrary anterior cortex of S₁ measured by anatomical measurement and computer tomography scan were 86.9±4.6 mm and 86.4±4.4 mm respectively.The distance from entry point on the posterolateral ilium to the center of pedicle of S₁ measured by anatomical measurement and computer tomography scan were 49.5±4.0 mm and 49.2±3.9 mm respectively.There was no significant difference between the results of anatomical measurement and computer tomography scan(P>0.05).The width of pedicle of S₁ measured by anatomical measurement and computer tomography scan were 27.7±2.0 mm and 20.7±2.5 mm respectively.There was significant difference between the results of anatomical measurement and computer tomography scan(P<0.01).11 patients with posterior pelvic fractures fixation with 13 iliosacral screws,there was no screw penetrating pedicle of S₁ or sacral vertebral body.Conclusions:The length of iliosacral screw can be accurately obtained from computer tomography scan.It is a safe and easy way for orthopaedist to select the length of scrw.