Abstract：
The purpose of this study is to investigate long-term changes in spinal sagittal balance after microsurgical decompression in lumbar canal stenosis (LCS).
Fifty-two patients who underwent microsurgical decompression for symptomatic single level L4/5 spinal canal stenosis at our hospital were included in the study. All patients had standing full spine radiographs taken preoperatively, 1 year postoperatively, and 5 years postoperatively. Spinal parameters including sagittal balance were measured from the obtained images. First, preoperative parameters were compared with 50 age-matched asymptomatic volunteers. Next, the parameters before and after surgery were compared to examine long-term changes.
Sagittal vertical axis (SVA) was significantly increased in the LCS cases compared to the volunteers (P = 0.03). Postoperative lumbar lordosis (LL) was significantly increased (P = 0.03). Postoperative mean SVA decreased but the difference was not significant (P = 0.12). Although there was no correlation between preoperative parameters and the Japanese Orthopedic Association score, postoperative pelvic incidence (PI)-LL and pelvic tilt changes correlated with changes in Japanese Orthopedic Association score (PI-LL; P = 0.0001, pelvic tilt; P = 0.04). However, after 5 years of surgery, LL decreased and PI-LL increased (LL; P = 0.08, PI-LL; P = 0.03). Sagittal balance began to deteriorate but was not significant (P = 0.31). At 5 years postoperatively, 18 of 52 patients (34.6%) were found to have L3/4 adjacent segment disease. Cases with adjacent segment disease showed significantly worse SVA and PI-LL (SVA; P = 0.01, PI-LL; P < 0.01).
In LCS, lumbar kyphosis improves and sagittal balance tends to improve after microsurgical decompression. However, after 5 years, adjacent intervertebral degeneration occurs more frequently and sagittal balance begins to deteriorate in about one third of cases.
Fifty-two patients who underwent microsurgical decompression for symptomatic single level L4/5 spinal canal stenosis at our hospital were included in the study. All patients had standing full spine radiographs taken preoperatively, 1 year postoperatively, and 5 years postoperatively. Spinal parameters including sagittal balance were measured from the obtained images. First, preoperative parameters were compared with 50 age-matched asymptomatic volunteers. Next, the parameters before and after surgery were compared to examine long-term changes.
Sagittal vertical axis (SVA) was significantly increased in the LCS cases compared to the volunteers (P = 0.03). Postoperative lumbar lordosis (LL) was significantly increased (P = 0.03). Postoperative mean SVA decreased but the difference was not significant (P = 0.12). Although there was no correlation between preoperative parameters and the Japanese Orthopedic Association score, postoperative pelvic incidence (PI)-LL and pelvic tilt changes correlated with changes in Japanese Orthopedic Association score (PI-LL; P = 0.0001, pelvic tilt; P = 0.04). However, after 5 years of surgery, LL decreased and PI-LL increased (LL; P = 0.08, PI-LL; P = 0.03). Sagittal balance began to deteriorate but was not significant (P = 0.31). At 5 years postoperatively, 18 of 52 patients (34.6%) were found to have L3/4 adjacent segment disease. Cases with adjacent segment disease showed significantly worse SVA and PI-LL (SVA; P = 0.01, PI-LL; P < 0.01).
In LCS, lumbar kyphosis improves and sagittal balance tends to improve after microsurgical decompression. However, after 5 years, adjacent intervertebral degeneration occurs more frequently and sagittal balance begins to deteriorate in about one third of cases.
摘要：
目的：本研究的目的是研究LCS显微手术减压后脊柱矢状面平衡的长期变化。
方法：在我院接受显微手术减压治疗有症状的单级L4/5椎管狭窄的52例患者被纳入研究。所有患者术前都有站立完整的脊柱X光片，术后1年,术后5年。从获得的图像测量包括矢状平衡的脊柱参数。首先,术前参数与50名年龄匹配的无症状志愿者进行比较.接下来,比较手术前后的参数以检查长期变化.
结果：与志愿者相比，LCS患者的SVA显著增加（p=0.03）。术后LL显著升高(p=0.03)。术后平均SVA下降，但差异不显着（p=0.12）。尽管术前参数与日本骨科协会（JOA）评分之间没有相关性，术后PI-LL和PT变化与JOA评分变化相关(PI-LL;p=0.0001,PT;p=0.04).然而,经过五年的手术，LL降低,PI-LL升高(LL;p=0.08,PI-LL;p=0.03)。矢状平衡开始恶化，但不显著（p=0.31）。术后五年，52例患者中有18例（34.6％）被发现患有L3/4相邻节段疾病（ASD）。ASD病例显示SVA和PI-LL显著恶化(SVA;p=0.01,PI-LL;p<0.01)。
结论：在LCS中，显微外科减压术后腰椎后凸畸形改善，矢状面平衡趋于改善。然而,五年后，在约三分之一的病例中，相邻椎间退化的发生频率更高，矢状平衡开始恶化。
方法：在我院接受显微手术减压治疗有症状的单级L4/5椎管狭窄的52例患者被纳入研究。所有患者术前都有站立完整的脊柱X光片，术后1年,术后5年。从获得的图像测量包括矢状平衡的脊柱参数。首先,术前参数与50名年龄匹配的无症状志愿者进行比较.接下来,比较手术前后的参数以检查长期变化.
结果：与志愿者相比，LCS患者的SVA显著增加（p=0.03）。术后LL显著升高(p=0.03)。术后平均SVA下降，但差异不显着（p=0.12）。尽管术前参数与日本骨科协会（JOA）评分之间没有相关性，术后PI-LL和PT变化与JOA评分变化相关(PI-LL;p=0.0001,PT;p=0.04).然而,经过五年的手术，LL降低,PI-LL升高(LL;p=0.08,PI-LL;p=0.03)。矢状平衡开始恶化，但不显著（p=0.31）。术后五年，52例患者中有18例（34.6％）被发现患有L3/4相邻节段疾病（ASD）。ASD病例显示SVA和PI-LL显著恶化(SVA;p=0.01,PI-LL;p<0.01)。
结论：在LCS中，显微外科减压术后腰椎后凸畸形改善，矢状面平衡趋于改善。然而,五年后，在约三分之一的病例中，相邻椎间退化的发生频率更高，矢状平衡开始恶化。
