Betts Andres
Pain MD Medical Associates, San Clemente, CA 92673, USA.
Pain Physician. 2008 Jan;11(1):57-65.
Sacral insufficiency fractures are a more commonly recognized cause of spine pain among osteoporotic patients, and are now treatable by sacroplasty using percutaneous instillation of PMMA cement. Sacroplasty may be performed using only fluoroscopic landmarks; however, the bony anatomy of the sacrum is complex and the cement deposition based on these landmarks has not been specifically confirmed. In this report we determined the precise fluoroscopic landmarks for cannula placement in a specially prepared excised sacral cadaveric specimen with metal surface markers. The cannulas were placed using the usual dorsal approach, and where the tip was visually seen to breach the cortical surface, fluoroscopic images were obtained and the boundaries of the sacrum were carefully determined. A fluoroscopic cortical "breach" area emerged where a cannula tip would likely be outside the cortical boundaries of the sacrum. With simple sacral vertebroplasty there is no direct control of cement deposition after the PMMA leaves the tip of the cannula. The use of vertebral augmentation devices may be of use to help control cement delivery in performing sacroplasty. We evaluated 2 such devices in cadaver specimens to determine their suitability in performing a sacral vertebral augmentation. Using these same landmarks, a sacral balloon Kyphoplasty was performed and the cadaveric specimen was subsequently bivalved to visually confirm the deposition of cement. On direct inspection the PMMA cement was found to be confined within the sacral cortical boundaries and there was no extravasation near or into the sacral foramen. Based on these fluoroscopic landmarks, the Arcuplasty device was tested in an intact cadaver to determine the optimal cannula placement and locations for creating osteotomies within the sacral trabecular bone prior to PMMA cement deposition. The cement deposition was observed to remain closely confined to the areas where the osteotomies were performed. In the balloon Kyphoplasty specimen the cement deposition was visually confirmed to be confined within the cortical boundaries by open dissection, and both devices have been found successful in creating a more controlled deposition of PMMA cement for performing sacral vertebral augmentation under fluoroscopic imaging.
骶骨不全骨折是骨质疏松患者脊柱疼痛的一种更常见的原因，目前可通过经皮注入聚甲基丙烯酸甲酯（PMMA）骨水泥的骶骨成形术进行治疗。骶骨成形术仅使用透视标志即可进行；然而，骶骨的骨解剖结构复杂，基于这些标志的骨水泥沉积尚未得到具体证实。在本报告中，我们在一个带有金属表面标记的特制切除骶骨尸体标本中确定了套管置入的精确透视标志。采用常规的背侧入路放置套管，当在视觉上看到套管尖端穿透皮质表面时，获取透视图像并仔细确定骶骨的边界。出现了一个透视皮质“穿透”区域，在此区域套管尖端可能位于骶骨皮质边界之外。在简单的骶骨椎体成形术中，PMMA离开套管尖端后，无法直接控制骨水泥的沉积。椎体增强装置可能有助于在进行骶骨成形术时控制骨水泥的输送。我们在尸体标本中评估了2种此类装置，以确定它们在进行骶骨椎体增强方面的适用性。使用这些相同的标志进行了骶骨球囊后凸成形术，随后将尸体标本一分为二，以直观确认骨水泥的沉积情况。经直接检查发现，PMMA骨水泥局限于骶骨皮质边界内，骶骨孔附近或内部没有渗漏。基于这些透视标志，在完整尸体中测试了弓形成形术装置，以确定在PMMA骨水泥沉积之前，在骶骨小梁骨内进行截骨术的最佳套管置入位置和位置。观察到骨水泥沉积紧密局限于进行截骨术的区域。在球囊后凸成形术标本中，通过开放解剖直观确认骨水泥沉积局限于皮质边界内，并且发现这两种装置在透视成像下进行骶骨椎体增强时，都成功地实现了对PMMA骨水泥更可控的沉积。
