Risk factors for early-onset radiographical adjacent segment disease in patients with spondylolytic spondylolisthesis after single-level posterior lumbar interbody fusion

BACKGROUND CONTEXTThe risk factors for radiographical adjacent segment disease (ASD) in patients with degenerative spondylolisthesis have been previously reported. However, there are only few reports on patients with spondylolytic spondylolisthesis who underwent single-level posterior lumbar interbody fusion (PLIF).PURPOSEThe study aimed to investigate the risk factors for radiographical ASD in patients with L5–S1 spondylolytic spondylolisthesis who underwent single-level PLIF.STUDY DESIGN/SETTINGA retrospective studyPATIENT SAMPLEThis study retrospectively reviewed 135 consecutive patients (91 men and 44 women) with symptomatic L5–S1 spondylolytic spondylolisthesis who underwent single-level PLIF.OUTCOME MEASURESThe pre- and postoperative (at the final follow-up) spinopelvic parameters, % slip, sacral slope, lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), PI minus LL (PI ? LL), lumbosacral angle, C7 sagittal vertical axis, and thoracic kyphosis were measured using standing radiographs.METHODSRadiographical ASD was defined as disc height loss (>3 mm), increase of posterior angulation (>5°), or progression of spondylolisthesis (>3 mm) between the pre- and postoperative radiographs. Pfirrmann's classification was used to evaluate disc degeneration. The radiographical parameters and changes between the pre- and postoperative values were evaluated and compared for the non-ASD and ASD groups. Binary logistic regression analysis was performed to evaluate the adjusted associations between each potential explanatory variable and ASD development.RESULTSThe radiographical ASD incidence was 11%. Additionally, 60% of the patients with ASD had radiographical ASD at 1 year and all cases of radiographical ASD in this follow-up period occurred within 3 years after the initial surgery. The mean period of ASD occurrence after initial surgery was 21.7 ± 12.6 months. No patients required reoperation for radiographical ASD. Multivariate analysis revealed that a preoperative (odds ratio [OR], 5.9; 95% confidence interval [CI], 1.2–28.9; p=.03) and a postoperative (OR, 6.5; 95% CI, 1.2–34.5; p=.03) PI ? LL of ≥15° were risk factors for radiographical ASD.CONCLUSIONSPre- and postoperative PI ? LL value mismatch was identified as significant independent risk factors for radiographical ASD in patients with L5–S1 spondylolytic spondylolisthesis. Obtaining larger lordosis at L5–S1 may be the key to preventing radiographical ASD.     

Lumbar trapezoid plate for lumbar spondylolisthesis. A clinical study on preoperative and postoperative instability

The authors studied the effects of a "lumbar trapezoid plate" (spinal plate and pedicle screwing), performed for lumbar spondylolisthesis, observing the effect on the remaining adjacent discs with regard to preoperative and postoperative instability. The authors examined changes in preoperative and postoperative lumbar ROM (range of motion), displacement of motor unit levels, and occurrence of instability in the remaining discs, such as horizontal and rotational displacement, in 26 patients who were followed up for a mean of 29 postoperative months; 13 patients had spondylolytic spondylolisthesis and 13 patients degenerative spondylolisthesis. The authors studied the effects of the fused vertebral angle and reduction of spondylolisthesis on the remaining upper and lower adjacent discs and the preoperative and postoperative fused disc heights. Intervertebral fusion must affect the remaining adjacent discs, but compensatory function of the remaining motor unit level was more influenced by the fused intervertebral angle than by repositioning of the spondylolisthesis. Fusion at a physiologically lordotic position is quite necessary. For this purpose, it is considered important to prevent grafted bones of the posterior lumbar interbody fusion (PLIF) from collapse and to maintain the achieved alignment of the lumbar spine.     

The radiographic parameters for the prediction of spondylolysis and spondylolisthesis

The grading of severity of spondylolisthesis and measurement of percentage slip are well-known radiological parameters that affect progression of the slip. The role of pelvic morphology and spino-pelvic balance in the prediction of spondylolisthesis has been recently scrutinized. Pelvic incidence, sacral slope, and pelvic tilt define the pelvic morphology and position. Pelvic incidence is most important as it determines the spino-pelvic balance, affects the biomechanical stresses at the lumbosacral junction, and predicts the progression of spondylolisthesis. A new classification by the Spinal Deformity Study Group incorporates pelvic morphological parameters and global sagittal balance and seeks to guide surgical management of spondylolisthesis.     

Radiological analysis of ankylosing spondylitis patients with severe kyphosis before and after pedicle subtraction osteotomy

This is a radiographic study of ankylosing spondylitis patients with severe fixed kyphotic deformity who underwent pedicle subtraction osteotomy. Our goal was to measure and validate new angle to assess global kyphosis and to evaluate the radiological outcomes after surgery. This is the first report which describes new angle to assess global kyphosis (T1-S1). Pre and postoperative controls were compared according to the Pelvic Incidence. The sagittal parameters ankylosing spondylitis patients were compared with 154 asymptomatic patients. In addition to the pelvic parameters and the C7 tilt, we used the spino-sacral angle. Pelvic incidence in ankylosing spondylitis patients was higher than asymptomatic population (61 vs. 51°). For a same tilt of C7 for both groups, the low pelvic incidence group had a lower sacral slope and pelvic tilt and a higher global kyphosis (spino-sacral angle = 90°) than the high pelvic incidence group (spino-sacral angle = 98°). In the adult volunteers, the C7 tilt and spino-sacral angle measured, respectively, 95 and 135°. The preoperative C7 tilt measured 73° and increased to 83° (p = 0.0025). The preoperative spino-sacral angle measured 96° and increased to 113.3° (p = 0.003). A low pelvic incidence pelvis has a lower sacral slope than in high pelvic incidence and can support a bigger kyphosis. All the parameters were improved by the pedicle subtraction osteotomy, but the average spino-sacral angle remained lower than the control group. When C7 tilt was useful to assess the improvement of the balance, SSA allowed a better evaluation of the correction of kyphosis itself.     

Anterior lumbar interbody fusion for lumbosacral junction in steep sacral slope

STUDY DESIGN: Retrospective study of surgical technique and clinical outcome. OBJECTIVES: To examine the technique and outcomes of anterior lumbar interbody fusion (ALIF) surgery for a lumbosacral junction in a steep sacral slope. SUMMARY OF BACKGROUND DATA: There are no studies on the outcome and technical pitfalls on ALIF surgery for a lumbosacral junction in a steep sacral slope. MATERIALS AND METHODS: Six female patients (mean age of 55.67 y; range, 42 to 69) who had a steep sacral slope underwent ALIF surgery for degenerative (2 patients) and spondylolytic (4 patients) spondylolisthesis. The average follow-up duration was 29.33 months (range, 27 to 33 mo). The following parameters were used to assess the outcomes: slip angle, slip percentage, sacral inclination, lumbosacral angle, sacral slope, and distance from the upper margin of the pubis symphysis to the sacral plane. The level of pain was measured using the visual analog pain scale score. The function was assessed using the Oswestry Disability Index (ODI) score. Satisfaction surveys were also carried out. Statistical analysis was performed using a Friedman test. A P value <0.05 was considered significant. RESULTS: The mean sacral inclination, lumbosacral angle, sacral slope, and distance from the upper margin of the pubis symphysis to the sacral plane were 37.34 degrees (range, 28.55 to 48.92 degrees), 12.20 degrees (range, 5.09 to 16.5 degrees), 40.70 degrees (range, 30.54 to 49.98 degrees), and 22.06 cm (range, 16.13 to 29.72 cm), respectively. The mean correction of slip percentage and slip angle was 35.46%, and 9.3 degrees, respectively. The mean visual analog pain scale score decreased from 8.5 (back pain) and 7.3 (leg pain) to 1.8 (back pain) and 1.8 (leg pain) after surgery (P=0.001). The mean ODI scores also reflected the improved status (ODI of 64.7 before surgery to 8.5 after surgery; P=0.001). The patient's satisfaction was relatively high. All the patients had radiographically solid fusion at the latest follow-up. There were no significant complications encountered in this study. CONCLUSIONS: In selected cases, a steep sacral slope may not be an absolute contraindication of ALIF. Moreover, the C-arm-guided reduction and cage insertion method is a reliable way of treating spondylolisthesis in those with a steep sacral slope.     

A slip above a slip: retrolisthesis of the motion segment above a spondylolytic spondylolisthesis

Objective

The purpose of this study is to assess the degenerative changes in the motion segments above a L5S1 spondylolytic spondylolisthesis and to view these in light of the retrolisthesis in the segment immediately above the slip.

Background summary

A spondylolytic spondylolisthesis causes an abnormal motion and predisposes to degenerative changes at the L5S1 disc. Degenerative changes in the adjacent segments would influence the symptomatology and natural history of the disease and the treatment options. The extent of degenerative changes in the levels immediately above a L5S1 spondylolytic spondylolisthesis is not well documented in the literature. We have noted retrolisthesis at this level, but this has not been previously reported or assessed.

Materials and methods

Thirty-eight patients with a symptomatic L5S1 spondylolytic spondylolisthesis with a mean age of 52.8 years (95% CI 47.2–58.4); 55.3% (n = 21) females and 44.7% (n = 17) males. We assessed the lumbar lordosis, slip angle, sacral slope, grade of the slip, facet angles at L34 and L45 on both sides, facet degenerative score (cartilage and sclerosis values), disc degenerative score (Pfirrmann) at L34, L45 and L5S1 and the presence of retrolisthesis at L45.

Results

We noted that 29% (11) had a retrolisthesis at L45. The degenerative scores reduced significantly from L5S1 through L45 and L34. Slip angle and L45 disc degenerative score were the only factors that occurred consistently in patients with a retrolisthesis.

Conclusions

There is a cascade of degenerative changes that involve both the disc and the facet joints at the levels above a spondylolytic spondylolisthesis. The degenerative changes at the L45 disc and a higher slip angle are consistent findings in patients with a retrolisthesis at the level above the slip.     

The sagittal anatomy of the sacrum among young adults,infants, and spondylolisthesis patients

The anatomic pelvic parameter "incidence" - the angle between the line perpendicular to the middle of the sacral plate and the line joining the middle of the sacral plate to the center of the bicoxo-femoral axis - has been shown to be strongly correlated with the sacral slope and lumbar lordosis, and ensures the individual an economical standing position. It is important for determining the sagittal curve of the spine. The angle of incidence has also been shown to depend partly on the sagittal anatomy of sacrum, which is established in childhood while learning to stand and walk. The purpose of this study was (1) to define the relationship between the sacrum and the angle of incidence, and (2) to compare these parameters in three populations: young adults, infants before walking, and patients with spondylolisthesis. Forty-four normal young adults, 32 infants not yet walking and 39 patients with spondylolisthesis due to isthmic spondylolysis underwent a sagittal full-spine radiography. A graphic table and the software for bidimensional study of the sacrum developed by J. Hecquet were used to determine various anatomic and positional parameters. Comparison tests of means, and multiple and partial correlation tests were used. A study of the reliability of the measurements using factorial plan methods was performed. The sagittal anatomic parameters of the sacrum were found to have a close relationship with the pelvic parameter of incidence angle, and therefore with the sagittal balance of the spine. The anatomy of the sacrum in spondylolisthesis patients is particular in that some features are much like those of young infants, but it is more curved and the incidence angle is significantly larger. There is a close relationship between angle of incidence and the slip of spondylolisthesis. All the parameters of young infants are significantly smaller than those of adults. It can be concluded that the sagittal anatomy of the sacrum plays a key role in spinal sagittal balance. The sacral bone is an integral a part of the pelvis and constitutes the undistorted part of the spinal curves. Organization of sagittal curves during growth can be followed up by looking at the sacrum. The sacrum in the spondylolisthesis group differs from the normal, and the greater angle of incidence and sacral slope in this group could predispose to vertebral slip.     

Postoperative instability after laminoplasty for cervical myelopathy with spondylolisthesis

OBJECTIVE: 76 patients who underwent laminoplasty for cervical spondylotic myelopathy were investigated regarding the impact of preoperative and postoperative degenerative spondylolisthesis on their neurologic outcome. METHODS: Radiographs were obtained 1 year postoperatively to investigate range of motion (ROM), lordotic curvature, and postoperative spondylolisthesis. RESULTS: By 1 year after surgery, 85% of those spondylolistheses present preoperatively had either resolved or improved on neutral lateral radiographs. The cross-sectional area of the spinal cord at the site of spondylolisthesis was measured using preoperative computed tomography myelography. Clinical results were evaluated by the recovery rate using Japanese Orthopaedic Association score. Patients with posterior spondylolisthesis showed a significantly poorer postoperative recovery rate. Intervertebral ROM in patients with preoperative spondylolisthesis was reduced, whereas cervical alignment had not deteriorated after laminoplasty. The group with posterior spondylolisthesis showed a significant reduction in the cross-sectional area of the spinal cord at the site of spondylolisthesis. Postoperative spondylolisthesis appeared in 15 patients, 10 of whom had preoperative spondylolisthesis at an adjacent site. CONCLUSION: The cause of poorer surgical results of those patients with preoperative posterior spondylolisthesis appears to be related to a higher degree of spinal cord compression than with preoperative anterior spondylolisthesis.     

腰椎滑脱复位和脊柱骨盆形态的相关性分析

目的探讨矢状面形态对腰椎滑脱复位的影响及复位与矢状面变化的关系。方法分析本院34例滑脱患者,根据滑脱复位程度分为部分复位组（〈50％）和完全复位组（〉50％）。矢状面参数包括骨盆倾斜角（PT）、胸椎后凸角（TK）、腰椎前凸角（LL）、骶骨倾斜角（SS）、矢状面偏移（SVA）、骨盆入射角（PI）。2组间差异采用配对样本和独立样本t检验。结果完全复位组11例,部分复位组23例。术后LL明显低于术前（P=0．000）;PT术前明显高于术后（P=0．017）;而PI、SS、TK和SVA手术前、后无明显变化（P〉0．05）。手术前后TK、LL、PI、SS、PT、SVA变化2组间差异无统计学意义（P〉0．05）。2组间术前TK、LL、PI、SS、PT、SVA差异无统计学意义（P〉0．05）。结论成人滑脱患者手术中,复位有利于减轻患者临床症状、提高患者生活质量,但复位并不能改善脊柱矢状面形态。     

腰椎滑脱症术后脊柱骨盆矢状面参数变化与临床疗效的相关性分析

目的观察退行性腰椎滑脱症患者术后脊柱骨盆矢状面参数变化,并评估术后疗效,探讨脊柱骨盆矢状面参数变化与临床疗效的相关性。方法纳入自2015-06—2017-01行后路腰椎椎体间融合术(PLIF)的30例L4、5退行性腰椎滑脱症。测量手术前后脊柱骨盆矢状面参数:骨盆入射角(PI)、骨盆倾斜角(PT)、骶骨倾斜角(SS)、腰椎前凸角(LL)、滑脱程度(SD)、椎间隙高度(DH)。采用Pearson相关分析脊柱骨盆矢状面参数与ODI指数、VAS评分的相关性。结果本组30例均获得3~19(12.73±7.06)个月随访。末次随访时VAS评分、ODI指数、PT、SS、LL、SD、DH较术前明显改善,差异有统计学意义(P0.05);而PI与术前比较差异无统计学意义(P0.05)。Pearson相关分析显示,术前PT、SD与术前ODI指数、VAS评分呈正相关,SS、LL、DH与ODI指数、VAS评分呈负相关,而PI与ODI指数、VAS评分无明显相关性。手术前后PT、SS、LL、SD、DH的变化值与ODI指数及VAS评分改善率呈正相关。结论退行性腰椎滑脱症患者术后脊柱骨盆矢状面参数改变与临床疗效存在相关性,术中应尽可能恢复脊柱骨盆矢状面平衡以获得良好疗效。     

影响腰椎滑脱手术复位的影像学预测因素及其临床意义

目的 研究可以预测腰椎滑脱手术复位疗效的影像学因素.方法 2001年5月至2007年4月行后路椎弓根螺钉复位内固定加后外侧融合术并且有完整影像学资料的患者42例,男性11例,女性31例;年龄40～79岁,平均56.0岁.其中退变性滑脱20例,崩裂性滑脱22例.L3,4滑脱1例,L4,5滑脱26例,L5S1滑脱15例.Ⅰ度滑脱23例,Ⅱ度滑脱19例.术前及术后1周常规行腰椎正、侧位X线片检查.在术前侧位X线片上测量滑脱率、椎间隙相对高度、滑脱角、腰前凸角和骶骨倾斜角;在术后侧位片上测量术后滑脱率.对复位率与术前滑脱率、术前滑脱角、术前椎间隙相对高度、术前腰前凸角和术前骶骨倾斜角的关联性采用多元回归分析.结果 42例患者术前滑脱率(22.5±10.6)%,术前椎间隙相对高度0.23±0.10,术前滑脱角4.4°±5.4°,术前腰前凸角43°±13°,术前骶骨倾斜角34°±10°,复位率(63.2±27.9)%.复位率与术前滑脱率、术前滑脱角和术前骶骨倾斜角无明显相关性,与术前椎间隙相对高度呈正相关(P<0.05),与术前腰前凸角呈正相关(P<0.05).结论 术前椎间隙相对高度和腰前凸角可以预测腰椎滑脱手术复位疗效.     

改良腰骶角评估骨盆前倾复位技术在儿童重度L5滑脱治疗中的应用

目的总结分析骨盆前倾复位技术在儿童重度L_5滑脱手术中的应用技巧,结合改良腰骶角(modified lumbosacral angle,m LSA)评估腰骶部畸形的纠正情况。方法回顾性分析2009年6月—2013年10月本院手术治疗的22例重度L_5滑脱(滑脱率50.0%)儿童患者的临床资料,其中男2例,女20例;年龄5~14岁,平均11.2岁;随访12~52个月,平均30个月。所有患者术中均予骨盆前倾复位技术复位滑脱椎体,纠正腰骶部后凸畸形。手术前后摄站立位全脊柱正侧位X线片,测量m LSA,评估椎体滑脱复位情况及后凸畸形纠正情况;行CT三维重建评估椎间融合情况;应用日本骨科学会(Japanese Orthopaedic Association,JOA)评分评估临床疗效。结果术后滑脱率1.0%~26.0%,平均7.45%,与术前相比差异具有统计学意义(P0.05)。m LSA术前为-(24.80°±8.42°),改善至术后前凸20.40°±6.27°,末次随访时为前凸19.80°±5.17°;JOA评分由术前(7.68±1.55)分,改善至术后(16.68±1.66)分,末次随访时为(15.77±1.85)分,术前与术后评分差异具有统计学意义(P0.05)。术后1年植骨融合率95.45%;并发症发生率9.09%(2/22),其中脑脊液漏1例,L_5神经根牵拉损伤1例。结论改良腰骶角测量评估骨盆前倾复位技术能有效复位滑脱椎体,纠正局部旋转畸形。     

Sacral and lumbar-pelvic morphology in high-grade spondylolisthesis

Numerous authors have stressed the importance of posterior arch, vertebral bodies, and intervertebral disk dysplastic changes in lumbosacral spondylolisthesis. An extensive morphologic analysis was conducted of the lumbosacral junction in a series of 100 consecutive patients presenting with severe lumbosacral spondylolisthesis. Statistical correlations were found between the pelvic incidence, sacral slope, and pelvic tilt, as found in healthy volunteers. A statistical relationship exists between the lumbosacral kyphosis and pelvic parameters that explains the global sagittal "balance" of this pathological posture. A well-defined morphological criterion, the "S1 index," strongly correlated with the severity and stiffness of lumbosacral spondylolisthesis.     

成人腰椎峡部裂型滑脱症的微创治疗

目的 探讨成人腰椎峡部裂型滑脱症的微创外科治疗方法与临床效果.方法 成人峡部裂型腰椎滑脱症患者21例,男12例,女9例;年龄29～73岁,平均51.7岁;L4.5滑脱7例,L5S1滑脱14例;双侧峡部裂19例,单侧2例.根据Meyerding分级:Ⅰ度滑脱13例,Ⅱ度滑脱7例,Ⅲ度滑脱1例.患者全麻,经后路双侧旁中央26 mm切口,在内镜辅助下行单侧或双侧椎管减压、椎间植骨cage融合、新型Sextant-R经皮椎弓根螺钉系统复位与内固定.结果 平均手术时间170 min,平均出血量160 ml,平均卧床时间7.5 d,平均住院时间19 d.20例患者获得随访,随访时间4～32个月,平均12.5个月.术后1年随访17例,患者VAS腰痛评分从术前平均(6.0±2.6)分降至(2.9±2.5)分;VAS腿痛评分从术前平均(6.7±3.3)分降至(2.8±1.6)分;Oswestry功能指数从术前平均44.3%降至27.1%;Nakai分级优良率90%.矢状面X线片腰椎滑脱率从术前35.5%±2.5%降至8.3%±7.5%,滑脱椎的腰前凸角从术前平均11.5°±1.7°增至16.8°±9.5°,椎间隙平均高度从术前(5.4±2.5)mm增至(9.1±3.0)mm.根据Lenke动态X线片评估标准:13例(76%)椎间骨性融合、2例(12%)椎间部分骨性融合、2例(12%)椎间无明显骨性融合.3例发生并发症.结论 内镜辅助下后路腰椎管减压、椎间植骨cage融合及经皮椎弓根螺钉系统复位与内固定治疗成人峡部裂型腰椎滑脱症手术创伤小,近期临床疗效好.     

脊柱－骨盆矢状位参数及关节突关节角度对退变性腰椎滑脱的影响

目的：探讨脊柱-骨盆矢状位参数及关节突关节角度对退变性腰椎滑脱的影响及相关性研究。方法：以2016年7月至2019年9月确诊的120例L₄-L₅单节段退变性滑脱患者为观察对象（滑脱组）,以性别和年龄相匹配的120例L₄-L₅节段退变性椎管狭窄患者为对照（对照组）。通过影像学资料测量如下参数：骨盆入射角（pelvic incidence,PI）,骨盆倾斜角（pelvic tilt,PT）,骶骨倾斜角（sacral slope,SS）,腰椎前凸（lumbar lordosis,LL）,胸椎后凸（thoracic kyphosis,TK）,矢状面平衡（sagittal vertical axis,SVA）,L₄-L₅头侧关节突关节角,尾侧关节突关节角及小关节不对称性。比较两组患者参数的差异并对有意义参数行Logistic回归分析。对退变性腰椎滑脱患者关节突关节方向与脊柱-骨盆参数进行相关性分析。结果：两组患者在PI、PT、LL、SVA、头侧关节突关节角、尾侧关节突关节角差异有统计学意义（P<0.05）;Logistic回归分析发现PI、PT及头侧关节突关节角是腰椎滑脱程度的危险因素（P<0.05）。滑脱组头侧关节突关节矢状化与PI、PT呈现显著相关（P<0.05）。结论：高PI、PT及头侧关节突关节矢状化是腰椎滑脱的危险因素,并且关节突关节矢状化程度和大PI、PT密切相关。     

重度腰椎滑脱术后骨盆一脊柱参数与临床症状的相关分析

目的研究重度峡部裂腰椎滑脱患者手术前后骨盆．脊柱参数的变化与临床症状改善的相关性。方法回顾性分析2000--2013年中南大学湘雅二医院收治的60例L,重度峡部裂滑脱患者的临床资料,根据术后Oswestry评分改善率的不同分为高改善率组（改善率〉50％）和低改善率组（改善率〈50％）,测量分析两组滑脱百分比、骨盆入射角（PI）、骨盆倾斜角（PT）、骶骨倾斜角（ss）、髋关节-S,水平距离（SFHD）、髋关节．s,垂直距离（SFVD）、腰椎前凸角（LL）、胸椎后凸角（TK）、C,铅垂线．骶骨后角距离（SC7D）、腰骶角（Dub—LSA）、腰骶关节角（LSJA）等数据。结果高改善率组PT、LL、SFHD、SC7D、LSJA、PT／SS、LL／TK、SFHD／SFVD均低于低改善率组（P〈O．05）,而SS、TK、SFVD、Dub．LSA均高于低改善率组（P〈O．05）。PT、LL、SFHD、SC7D、LSJA与Oswestry评分改善率呈显著负相关,负相关程度依次为SC7D〉LL〉PT〉SFHD〉LSJA（P〈0．05）;SS、TK、SFVD、Dub．LSA与Oswestry评分改善率呈显著正相关,正相关程度依次为：Dub—LSA〉SS〉SFVD〉TK（P〈0．05）：PT／SS、SFHD／SFVD、LL／TK与Oswestry评分改善率呈显著负相关,负相关程度依次为：PT／SS〉LL／TK〉SFHD／SFVD（P〈0．05）,这3个参数比值与术后Oswestry评分改善率的相关性均大于单个参数与术后评分改善率的相关性（P〈0．05）。结论重度腰椎滑脱患者术后临床症状与骨盆．脊柱参数关系密切,临床症状改善率与PT、LL、SFHD、SC7D、LSJA、PT／SS、SFHD／SFVD、LL／TK呈负相关,与SS、TK、SFVD、Dub．LSA呈正相关。提示对于此类患者,术前应充分评估可能影响术后症状改善的因素,优先考虑矫正影响较大的参数,并设计合理军术方寨．以樨高疗前。     

Lumbar posterolateral fusion alone or with transpedicular instrumentation in L4--L5 degenerative spondylolisthesis

We retrospectively reviewed 57 patients with L4--L5 degenerative spondylolisthesis (L4--L5 DS) who underwent posterior decompression and posterolateral fusion of L4--L5 without (Group A) or with (Group B) transpedicular screw instrumentation at least 2 years earlier. The clinical results and fusion rate were similar between Groups A and B, that is, a 72.4% satisfactory outcome with a fusion rate of 82.8% in Group A versus 82.1% satisfactory outcome with a 92.8% fusion rate in Group B. Screw instrumentation reduced postoperative low back pain and resulted in a lordotic slip angle of L4--L5. However, in patients with radiologically excessive segmental motion showing a translational motion of 3 mm or more, flexion angulation of -5 degrees or less, and a slip angle of -5 degrees or less at the site of spondylolisthesis (L4--L5), the kyphotic slip angle (L4--L5) tended to increase after surgery. In the future, in patients with radiologically excessive segmental motion, this point should be considered, and surgical techniques should be evaluated. Our results suggest that the validity of the general addition of screw instrumentation to L4--L5 fusion for L4--L5 degenerative spondylolisthesis is low.     

Impact of lumbar fusion on spinopelvic sagittal alignment from standing to sitting position: which factor is associated with postoperative functional limitations due to lumbar stiffness?

Purpose

To investigate the impact of lumbar fusion on spinopelvic sagittal alignment from standing to sitting position and the influencing factors of postoperative functional limitations due to lumbar stiffness.

Methods

A total of 107 patients who undertook posterior lumbar interbody fusion were included. Patients were divided into two groups: Group A (lumbosacral fusion; n = 43) and Group B (floating fusion; n = 64). Spinopelvic parameters in standing and sitting position including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), fusion segment lordosis (FSL), upper residual lordosis (URL), lower residual lordosis (LRL), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), sagittal vertical axis (SVA) and T1 pelvic angle (TPA) were measured before and after lumbar fusion. The Lumbar Stiffness Disability Index (LSDI) was used to assess functional limitations due to lumbar stiffness.

Results

Accompanied by increased postoperative LSDI, the values of changes from standing to sitting (∆) were reduced in some parameters compared with the preoperative values. ∆PT and ∆SS significantly decreased in both two groups. In Group A, ∆LL significantly decreased with increased ∆URL. In Group B, ∆LL, ∆URL and ∆LRL showed no significant difference before and after surgery. Multiple linear regression analysis showed that age and ∆PT independently influenced the postoperative LSDI in Group A.

Conclusion

After lumbar fusion, changes of lumbopelvic sagittal parameters from standing to sitting would be restricted. Adjacent segment lordosis could partially compensate for this restriction. For patients with lumbosacral fusion, postoperative functional limitations due to lumbar stiffness were related to age and the postoperative ∆PT from standing to sitting.

     

The Current Proposed Total Hip Arthroplasty Surgical Planning Guidelines Based on Classification of Spine Stiffness May be Flawed Due to Incorrect Assumptions

BackgroundThe available classifications and preoperative planning tools for total hip arthroplasty assume that: 1) there is no variation in the sagittal pelvic tilt (SPT) if the radiographs are repeated, and 2) there is no significant change in the postoperative SPT postoperatively. We hypothesized that there would be significant differences in postoperative SPT tilt as measured by the sacral slope, thus rendering the current classifications and tools flawed.MethodsThis study was a multicenter, retrospective analysis of preoperative and postoperative (1.5-6 months) full-body imaging of 237 primary total hip arthroplasty (standing and sitting positions). Patients were categorized as 1) stiff spine (standing sacral slope sitting sacral slope < 10°) and 2) normal spine (standing sacral slope-sitting sacral slope ≥ 10°). Results were compared using the paired t-test. The posthoc power analysis showed a power of 0.99.ResultsThe difference in mean standing and sitting sacral slope between the preoperative and postoperative measurements was 1°. However, in standing position, this difference was more than 10° in 14.4% of patients. In the sitting position, this difference was more than 10° in 34.2% of patients and more than 20° in 9.8% of patients. Postoperatively, 32.5% of patients switched groups based on the classification, which rendered the preoperative planning suggested by the current classifications flawed.ConclusionCurrent preoperative planning and classifications are based on a single acquisition of preoperative radiographs without the incorporation of possible postoperative changes in SPT. Validated classifications and planning tools should incorporate repeated measurements to determine the mean and variance in SPT and consider the significant postoperative changes in SPT.