Department of Spine Surgery, Hospital for Special Surgery, New York, NY.
University of Tokyo Spine Group (UTSG), Tokyo, Japan.
Spine (Phila Pa 1976). 2024 Jul 15;49(14):990-996. doi: 10.1097/BRS.0000000000004782. Epub 2023 Jul 24.
Retrospective cohort study.
This study aimed to evaluate the association between nerve lengthening after adult deformity correction and motor deficits dervied from the upper lumbar plexus or femoral nerve.
Adult spinal deformity (ASD) surgery is associated with high rates of neurological deficits. Certain postoperative deficits may be related to lengthening of the upper lumbar plexus (ULP) and/or femoral nerve (FN) after correction of lumbar deformity.
Patients with ASD who underwent posterior-only corrective surgery from the sacrum to L3 or above were included. The length of each lumbar nerve root was calculated geometrically using the distance from the foramen to the midpoint between the anterosuperior iliac crest and pubic symphysis on AP and lateral radiographs. The mean lengths of the L1 to 3 and L2 to 4 nerve roots were used to define the lengths of the ULP and FN, respectively. Preoperative to postoperative changes in nerve length were calculated. Neurological examination was performed at discharge. Proximal weakness (PW) was defined as the presence of weakness compared with baseline in either hip flexors or knee extensors. Multiple linear regression analysis was used for estimating the postoperative lengthening according to the magnitude of preoperative curvature and postoperative correction angles.
A total of 202 sides were analyzed in 101 patients, and PW was present on 15 (7.4%) sides in 10 patients. Excluding the 10 cases with three-column osteotomies, those with PW had a significantly higher rate of pure sagittal deformity ( P <.001) and greater nerve lengthening than those without PW (ULP 24 vs. 15 mm, P =0.02; FN 18 vs. 11 mm, P =0.05). No patient had advanced imaging showing neural compression, and complete recovery of PW occurred in eight patients at one-year follow-up.
After ASD surgery, lengthening of the ULP was associated with PW. In preoperative planning, surgeons must consider how the type of correction may influence the risk for nerve lengthening, which may contribute to postoperative neurological deficit.
回顾性队列研究。
本研究旨在评估成人脊柱畸形（ASD）矫正后神经延长与上腰丛或股神经运动缺陷之间的关系。
成人脊柱畸形（ASD）手术与神经功能缺损发生率高有关。某些术后缺陷可能与腰椎畸形矫正后上腰丛（ULP）和/或股神经（FN）的延长有关。
纳入接受后路单纯矫正手术（从骶骨至 L3 或以上）的 ASD 患者。使用前后位和侧位 X 线片上从椎间孔到髂前上棘和耻骨联合中点的距离，对每个腰椎神经根的长度进行几何计算。L1 至 3 和 L2 至 4 神经根的平均长度分别用于定义 ULP 和 FN 的长度。计算神经长度的术前到术后变化。出院时进行神经检查。近端肌无力（PW）定义为与基线相比，髋关节屈肌或膝关节伸肌出现无力。使用多元线性回归分析根据术前曲度和术后矫正角度的大小来估计术后延长。
共分析了 101 例患者的 202 侧，10 例患者的 15 侧（7.4%）存在 PW。排除 10 例三柱截骨患者后，PW 组的纯矢状面畸形发生率明显更高（P<0.001），神经延长程度也明显大于无 PW 组（ULP 24 毫米比 15 毫米，P=0.02；FN 18 毫米比 11 毫米，P=0.05）。没有患者有神经压迫的影像学证据，8 例 PW 患者在一年随访时完全恢复。
ASD 手术后，ULP 的延长与 PW 有关。在术前规划中，外科医生必须考虑到矫正类型如何影响神经延长的风险，这可能导致术后神经功能缺损。
