Kawahara Norio, Murakami Hideki, Yoshida Akira, Sakamoto Jiro, Oda Juhachi, Tomita Katsuro
Department of Orthopaedic Surgery, Kanazawa University, Kanazawa, Japan.
Spine (Phila Pa 1976). 2003 Jul 15;28(14):1567-72.
The stresses exerted on the instrumentation and adjacent bone were evaluated for three reconstruction methods after a total sacrectomy: a modified Galveston reconstruction (MGR), a triangular frame reconstruction (TFR), and a novel reconstruction (NR).
To perform finite-element analysis of reconstruction methods used after a total sacrectomy.
When a sacral tumor involves the first sacral vertebra, a total sacrectomy is necessary. It is mandatory to reconstruct the continuity between the spine and the pelvis after a total sacrectomy. However, no previous reports have described a biomechanical study of the reconstructed lumbosacral spine.
A finite-element model of the lumbar spine and pelvis was constructed. Then three-dimensional MGR, TFR, and NR models were reconstructed, and a finite-element analysis was performed to account for the stresses on the bones and instrumentation.
With excessive stress concentrated at the spinal rod in MGR, there is a strong possibility that the rod between the spine and the pelvis may fail. Although there was no stress concentration on the instruments in TFR, excessive stress on the iliac bones around the sacral rod was above the yield stress of the iliac bone. Such stress may cause a loosening of the sacral rod from the iliac bone. In NR, excessive stress concentration was not detected in the rod or the bones. This reconstruction has a low risk of instrument failure and loosening.
If the patient were to stand or sit immediately after MGR or TFR instrumentation, failure or loosening may occur. The NR has a low risk of instrument failure and loosening after a total sacrectomy.
对全骶骨切除术后的三种重建方法（改良加尔维斯顿重建术（MGR）、三角框架重建术（TFR）和新型重建术（NR））施加于器械及相邻骨骼的应力进行评估。
对全骶骨切除术后使用的重建方法进行有限元分析。
当骶骨肿瘤累及第一骶椎时，需行全骶骨切除术。全骶骨切除术后重建脊柱与骨盆之间的连续性是必需的。然而，此前尚无关于重建腰骶椎生物力学研究的报道。
构建腰椎和骨盆的有限元模型。然后重建三维MGR、TFR和NR模型，并进行有限元分析以评估骨骼和器械上的应力。
在MGR中，应力过度集中于脊柱棒，脊柱与骨盆之间的棒很有可能失效。虽然TFR的器械上没有应力集中，但骶骨棒周围髂骨上的过度应力高于髂骨的屈服应力。这种应力可能导致骶骨棒与髂骨松动。在NR中未检测到棒或骨骼上的过度应力集中。这种重建方法器械失效和松动的风险较低。
如果患者在MGR或TFR器械植入后立即站立或坐下，可能会发生失效或松动。全骶骨切除术后，NR器械失效和松动的风险较低。
