Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

Delayed complications following lumbar spine fusion may occur amongst which is adjacent segment degeneration (ASD). Although interspinous implants have been successfully used in spinal stenosis to authors’ knowledge such implants have not been previously used to reduce ASD in instrumented lumbar fusion. This prospective controlled study was designed to investigate if the implantation of an interspinous implant cephalad to short lumbar and lumbosacral instrumented fusion could eliminate the incidence of ASD and subsequently the related re-operation rate. Groups W and C enrolled initially each 25 consecutive selected patients. Group W included patients, who received the Wallis interspinous implant in the unfused vertebral segment cephalad to instrumentation and the group C selected age-, diagnosis-, level-, and instrumentation-matched to W group patients without interspinous implant (controls). The inclusion criterion for Wallis implantation was UCLA arthritic grade <II, while the exclusion criteria were previous lumbar surgery, severe osteoporosis or degeneration >UCLA grade II in the adjacent two segments cephalad to instrumentation. All patients suffered from symptomatic spinal stenosis and underwent decompression and 2–4 levels stabilization with rigid pedicle screw fixation and posterolateral fusion by a single surgeon. Lumbar lordosis, disc height (DH), segmental range of motion (ROM), and percent olisthesis in the adjacent two cephalad to instrumentation segments were measured preoperatively, and postoperatively until the final evaluation. VAS, SF-36, and Oswestry Disability Index (ODI) were used. One patient of group W developed pseudarthrosis: two patients of group C deep infection and one patient of group C ASD in the segment below instrumentation and were excluded from the final evaluation. Thus, 24 patients of group W and 21 in group C aged 65+ 13 and 64+ 11 years, respectively were included in the final analysis. The follow-up averaged 60 ± 6 months. The instrumented levels averaged 2.5 + 1 vertebra for both groups. All 45 spines showed radiological fusion 8–12 months postoperatively. Lumbar lordosis did not change postoperatively. Postoperatively at the first cephalad adjacent segment: DH increased in the group W (P = 0.042); ROM significantly increased only in group C (ANOVA, P < 0.02); olisthesis decreased both in flexion (P = 0.0024) and extension (P = 0.012) in group W. The degeneration or deterioration of already existed ASD in the two cephalad segments was shown in 1 (4.1%) and 6 (28.6%) spines in W and C groups, respectively. Physical function (SF-36) and ODI improved postoperatively (P < 0.001), but in favour of the patients of group W (P < 0.05) at the final evaluation. Symptomatic ASD required surgical intervention was in 3 (14%) patients of group C and none in group W. ASD remains a significant problem and accounts for a big portion of revision surgery following instrumented lumbar fusion. In this series, the Wallis interspinous implant changed the natural history of ASD and saved the two cephalad adjacent unfused vertebra from fusion, while it lowered the radiographic ASD incidence until to 5 years postoperatively. Longer prospective randomized studies are necessary to prove the beneficial effect of the interspinous implant cephalad and caudal to instrumented fusion. We recommend Wallis device for UCLA degeneration I and II.     

The effect of Luque-rod instrumentation on the sagittal contour of the lumbosacral spine in adolescent idiopathic scoliosis and the preservation of a physiologic lumbar lordosis.

The changes in the sagittal alignment of the lumbar spine were investigated in 28 patients with adolescent idiopathic scoliosis undergoing long posterior spinal fusion to L4 or L5 with contoured Luque rods and segmental sublaminar wiring. The lumbar lordosis over the instrumented levels was preserved, and there was no compensatory hyperlordosis of vertebral segments distal to the fusion. In situations where long posterior spinal fusions are indicated, instrumentation with contoured Luque rods and segmental sublaminar wiring can preserve the normal sagittal alignment of the lumbosacral spine.     

Sagittal spinal alignment in patients with lumbar disc herniation

A retrospective cross-sectional study was designed to evaluate total sagittal spinal alignment in patients with lumbar disc herniation (LDH) and healthy subjects. Abnormal sagittal spinal alignment could cause persistent low back pain in lumbar disease. Previous studies analyzed sciatic scoliotic list in patients with lumbar disc herniation; but there is little or no information on the relationship between sagittal alignment and subjective findings. The study subjects were 61 LDH patients and 60 age-matched healthy subjects. Preoperative and 6-month postoperatively lateral whole-spine standing radiographs were assessed for the distance between C7 plumb line and posterior superior corner on the top margin of S1 sagittal vertical axis (SVA), lumbar lordotic angle between the top margin of the first lumbar vertebra and first sacral vertebra (L1S1), pelvic tilting angle (PA), and pelvic morphologic angle (PRS1). Subjective symptoms were evaluated by the Japanese Orthopedic Association (JOA) score for lower back pain (nine points). The mean SVA value of the LDH group (32.7 ± 46.5 mm, ± SD) was significantly larger than that of the control (2.5 ± 17.1 mm), while L1S1 was smaller (36.7 ± 14.5°) and PA was larger (25.1 ± 9.0°) in LDH than control group (49.0 ± 10.0° and 18.2 ± 6.0°, respectively). At 6 months after surgery, the malalignment recovered to almost the same level as the control group. SVA correlated with the subjective symptoms measured by the JOA score. Sagittal spinal alignment in LDH exhibits more anterior translation of the C7 plumb line, less lumbar lordosis, and a more vertical sacrum. Measurements of these spinal parameters allowed assessment of the pathophysiology of LDH.     

Can formetric 4D measurements predict the development of adjacent segment degeneration after single-segment PLIF?: Relative rotation angle as a sensitive predictor

BackgroundAdjacent segment degeneration (ASD) is a major issue after posterior lumbar interbody fusion (PLIF). The postoperative dynamic change of adjacent segments remains unknown. Hence, this study using the formetric 4D system (DIERS, International GmbH of Schlangenbad, Germany) to determine the impact of PLIF on ASD, and to compare the effectiveness with traditional radiography for the predication of ASD.MethodsEighty-five consecutive patients who underwent PLIF of a single-segment were included. The formetric 4D system was used to calculate the relative rotation angle between the fusion segment and the upper and lower adjacent vertebrae before and at 6, 12 and 24 months after surgery. The range of motion (ROM) and disc height (DH) of adjacent segments were measured using radiography before surgery and 24 months postoperatively. At the final follow-up, the visual analogue scale (VAS) and Oswestry disability index were used to evaluate the surgical outcome. The patients were divided into two groups according to the occurrence of radiographic ASD: the ASD group with progression of degeneration and the N-ASD group without progression of degeneration.ResultsThe index fusion segments included L2-3 to L5-S1. Preoperatively, the relative rotation angles formed by the fusion segment with the upper and lower adjacent vertebrae were 5.1° ± 2.2° and 3.3° ± 2.0°, respectively, and both angles increased significantly at all time points after surgery (p < 0.05). The angles changed most significantly during L2-3 fusion. Radiographic ASD developed in 13 of 85 patients (15.3%) at 24 months. And the relative rotation angle with the upper adjacent vertebra was larger in the ASD group than in the N-ASD group (p < 0.05).ConclusionThe relative rotation angle with adjacent vertebra increased significantly after lumbar fusion surgery. It may be a more sensitive predictor than the flexion-extension ROM and DH for the development of radiographic ASD.     

Comparison of adjacent segment degeneration after successful posterolateral fusion with unilateral or bilateral pedicle screw instrumentation: a minimum 10-year follow-up

Background context

In the instrumented fusion, adjacent segment facet joint violation or impingement by pedicle screws is unavoidable especially in cephalad segment, despite taking specific intraoperative precautions in terms of surgical approach. In such circumstances, unlike its original purpose, unilateral pedicle screw instrumentation can contribute to reduce the degeneration of cephalad adjacent segment by preventing contralateral cephalad adjacent facet joint from the unavoidable injury by pedicle screw insertion. However, to our knowledge, no long-term follow-up study has compared adjacent segment degeneration (ASD) between unilateral and bilateral pedicle screw instrumented fusion.

Purpose

To compare ASD after successful posterolateral fusion using either unilateral or bilateral pedicle screw instrumentation for patients with lumbar spinal stenosis and/or Grade 1 spondylolisthesis.

Study design

Retrospective case-control study.

Patient sample

One hundred forty-seven patients who had undergone one- or two-level posterolateral fusion with unilateral or bilateral pedicle screw instrumentation for lumbar spinal stenosis with or without low-grade spondylolisthesis and achieved successful fusion, with a minimum 10-year follow-up.

Outcome measure

The occurrence of radiologic ASD, Oswestry disability index (ODI) scores, and revision rates.

Methods

A total of 194 consecutive patients were contacted and encouraged to visit our hospital and to participate in our study. Radiologic ASD was evaluated at three motion segments: cephalad adjacent segment (first cephalad adjacent segment), one cephalad to cephalad adjacent segment (second cephalad adjacent segment), and caudal adjacent segment. Clinical outcomes were compared by ODI scores and revision rates.

Results

In total, 147 of 194 (75.8%) patients were available for at least 10 years of radiologic and clinical follow-up. Adjacent segment degeneration (in first cephalad or caudal adjacent segment) was noted in 55.9% (33 of 59 patients) of the unilateral group and 72.7% (64 of 88 patients) of the bilateral group (p=.035). The occurrence of ASD in each first cephalad and caudal adjacent segment was not significantly different between groups but that in second cephalad adjacent segment was significantly different between groups (p=.004). Clinical outcomes according to ODI showed significant difference between groups (p=.016), especially when ODI scores were compared in patients with ASD (p=.004).

Conclusions

In a minimum 10-year follow-up retrospective study of posterolateral fusion for lumbar spinal stenosis and/or Grade 1 spondylolisthesis, unilateral pedicle screw instrumentation showed a lower rate of radiologic ASD, especially in second cephalad adjacent segment, and a better clinical outcome by ODI.     

Prognosis and adjacent segment disease after lumbar spinal fusion surgery for destructive spondyloarthropathy in long-term hemodialysis patients

Background

Lumbar destructive spondyloarthropathy (DSA) is a serious complication in long-term hemodialysis patients. There have not been many reports regarding the surgical management for lumbar DSA. In addition, the adjacent segment pathology after lumbar fusion surgery for DSA is unclear. The objective of this study was to assess the clinical outcome and occurrence of adjacent segmental disease (ASD) after lumbar instrumented fusion surgery for DSA in long-term hemodialysis patients.

Kinematic evaluation of the adjacent segments after lumbar instrumented surgery: a comparison between rigid fusion and dynamic non-fusion stabilization

The aim of the current study was to evaluate changes in lumbar kinematics after lumbar monosegmental instrumented surgery with rigid fusion and dynamic non-fusion stabilization. A total of 77 lumbar spinal stenosis patients with L4 degenerative spondylolisthesis underwent L4–5 monosegmental posterior instrumented surgery. Of these, 36 patients were treated with rigid fusion (transforaminal lumbar interbody fusion) and 41 with dynamic stabilization [segmental spinal correction system (SSCS)]. Lumbar kinematics was evaluated with functional radiographs preoperatively and at final follow-up postoperatively. We defined the contribution of each segmental mobility to the total lumbar mobility as the percent segmental mobility [(sagittal angular motion of each segment in degrees)/(total sagittal angular motion in degrees) × 100]. Magnetic resonance imaging was performed on all patients preoperatively and at final follow-up postoperatively. The discs were classified into five grades based on the previously reported system. We defined the progress of disc degeneration as (grade at final follow-up) − (grade at preoperatively). No significant kinematical differences were shown at any of the lumbar segments preoperatively; however, significant differences were observed at the L2–3, L4–5, and L5–S1 segments postoperatively between the groups. At final follow-up, all of the lumbar segments with rigid fusion demonstrated significantly greater disc degeneration than those with dynamic stabilization. Our results suggest that the SSCS preserved 14% of the kinematical operations at the instrumented segment. The SSCS may prevent excessive effects on adjacent segmental kinematics and may prevent the incidence of adjacent segment disorder.     

Lumbar spine surgery in patients with rheumatoid arthritis (RA): what affects the outcomes?

Background Context

Although the cervical spine is only occasionally involved in rheumatoid arthritis (RA), involvement of the lumbar spine is even less common. A few reports on lumbar spinal stenosis in patients with RA have appeared. Although disc space narrowing occurs in aging, postoperative adjacent segment disease (ASD) in patients with RA has not been subject to much analysis.

Extension CT scan: its suitability for assessing fusion after posterior lumbar interbody fusion

Posterior lumbar interbody fusion (PLIF) is a popular procedure for treating lumbar canal stenosis with spinal instability, and several reports concerning fusion assessment methods exist. However, there are currently no definitive criteria for diagnosing a successful interbody fusion in the lumbar spine. We suggested evaluating fusion status using computed tomography (CT) in extension position to detect pseudoarthrosis more precisely. The purpose of this study was to evaluate its usefulness for determining bone union quality after PLIF. Eighty-one patients who underwent PLIF at 97 levels were retrospectively enrolled. The study population included 48 men and 33 women (mean age 58.9 years, range 21–85 years). Patients were followed up for more than 12 months after surgery. The mean follow-up period was 27.6 months (range 14–49 months). Fusion status was evaluated using three ways: flexion–extension radiographs, CT images in flexion and extension position. In the flexion–extension radiographs, mobility of more than 3°, a remaining clear zone, or an uncertain bone connection constituted an incomplete union. For CT images, a remaining clear zone, a gas pattern, or an uncertain bone connection constituted an incomplete union. Flexion–extension radiographs demonstrated a solid fusion in 90.7% of the 97 levels at 10.7 months postoperatively. When fusion was demonstrated on flexion–extension radiographs, the rate of fusion affirmed by flexion CT and extension CT was 87.6 and 69.1% of the levels assessed, respectively. The rate of pseudoarthrosis detected on extension CT images was significantly higher than that on flexion–extension radiographs (P < 0.001) and flexion CT (P < 0.01). The rate of fusion achieved on extension CT was 85.6% at 15.1 months postoperatively. Extension CT could detect pseudoarthrosis more clearly than flexion–extension radiography and flexion CT. The CT images are influenced by body position and dilating anterior disc space in extension CT contributes to detect pseudoarthrodesis. Thus, extension CT was a useful method for assessing fusion status after PLIF.     

Risk factors for adjacent segment disease after lumbar fusion

The incidence of adjacent segment problems after lumbar fusion has been found to vary, and risk factors for these problems have not been precisely verified, especially based on structural changes determined by magnetic resonance imaging. The purpose of this retrospective clinical study was to describe the incidence and clinical features of adjacent segment disease (ASD) after lumbar fusion and to determine its risk factors. We assessed the incidence of ASD in patients who underwent lumbar or lumbosacral fusions for degenerative conditions between August 1995 and March 2006 with at least a 1-year follow-up. Patients less than 35 years of age at the index spinal fusion, patients with uninstrumented fusion, and patients who had not achieved successful union were excluded. Of the 1069 patients who underwent fusions, 28 (2.62%) needed secondary operations because of ASD and were included in this study. In order to identify the risk factors, we matched a disease group and a control group. The disease group consisted of 26 of the 28 patients with ASD, excluding the 2 patients for whom we did not have initial MRI data. Each patient in the disease group was matched by age, sex, fusion level and follow-up period with a control patient. The assumed risk factors included disc and facet degeneration, instability, listhesis, rotational deformity, and disc wedging. The mean age of the 28 patients with ASD requiring surgical treatment was 58.4 years, which did not differ significantly from that of the population in which ASD did not develop (58.2 years, p = 0.894). Of the 21 patients who underwent floating fusion, only 1 developed distal ASD. Facet degeneration was a significant risk factor (p < 0.01) on logistic regression analysis. The incidence of distal ASD was much lower than that of proximal ASD. Pre-existing facet degeneration may be associated with a high risk of adjacent segment problems following lumbar fusion procedures.     

Pelvic incidence–lumbar lordosis mismatch results in increased segmental joint loads in the unfused and fused lumbar spine

Purpose

Symptomatic adjacent segment disease (ASD) has been reported to occur in up to 27 % of lumbar fusion patients. A previous study identified patients at risk according to the difference of pelvic incidence and lordosis. Patients with a difference between pelvic incidence and lumbar lordosis >15° have been found to have a 20 times higher risk for ASD. Therefore, it was the aim of the present study to investigate forces acting on the adjacent segment in relation to pelvic incidence–lumbar lordosis (PILL) mismatch as a measure of spino-pelvic alignment using rigid body modeling to decipher the underlying forces as potential contributors to degeneration of the adjacent segment.

Methods

Sagittal configurations of 81 subjects were reconstructed in a musculoskeletal simulation environment. Lumbar spine height was normalized, and body and segmental mass properties were kept constant throughout the population to isolate the effect of sagittal alignment. A uniform forward/backward flexion movement (0°–30°–0°) was simulated for all subjects. Intervertebral joint loads at lumbar level L3–L4 and L4–L5 were determined before and after simulated fusion.

Results

In the unfused state, an approximately linear relationship between sagittal alignment and intervertebral loads could be established (shear: 0° flexion r = 0.36, p < 0.001, 30° flexion r = 0.48, p < 0.001; compression: 0° flexion r = 0.29, p < 0.01, 30° flexion r = 0.40, p < 0.001). Additionally, shear changes during the transition from upright to 30° flexed posture were on average 32 % higher at level L3–L4 and 14 % higher at level L4–L5 in alignments that were clinically observed to be prone to ASD. Simulated fusion affected shear forces at the level L3–L4 by 15 % (L4–L5 fusion) and 23 % (L4–S1 fusion) more for alignments at risk for ASD.

Conclusion

Higher adjacent segment shear forces in alignments at risk for ASD already prior to fusion provide a mechanistic explanation for the clinically observed correlation between PILL mismatch and rate of adjacent segment degeneration.     

Wallis棘突间动态稳定系统对缓解腰椎融合术后邻近节段退变的临床疗效分析

目的：在行腰椎管减压融合的手术中,置入Wallis棘突间稳定系统,分析其缓解邻近节段腰椎退变的疗效。方法：自2007年7月至2009年7月,采用腰椎后路减压融合内固定术治疗腰椎退变性疾病患者40例（男16例,女24例,年龄25-60岁）,其中20例患者行腰椎后路减压融合内固定术的同时于具有退变趋势的邻近节段置入棘突间稳定系统Wallis固定（试验组）,其余20例单纯行腰椎后路减压融合内固定术（对照组）。分别于置入后1个月、3年对两组患者进行术后的JOA评分和目测类比评分（VAS）,同时测量并计算两组患者手术前后邻近节段椎间隙高度和椎管面积的变化情况。结果：40例患者均获得随访,时间3~5年,平均3．6年。40侧患者伤口均I类甲级愈合,术后疼痛情况均较术前缓解。两组患者置入后1个月JOA及VAS评分比较差异无统计学意义（P〉0．05）;术后3年JOA及VAS评分比较差异有统计学意义（P〈0。05）。两组患者术后1个月邻近节段椎间隙高度、椎管面积变化比较差异无统计学意义（尸〉0．05）;术后3年邻近节段椎间隙高度、椎管面积变化比较差异有统计学意义（R0．05）。结论：两种术式即刻效果无差异,均能取得良好的效果,此效果主要依赖于手术有效的减压。试验组中期效果明显优于对照组,主要是棘突间稳定系统Wallis发挥良好的生物学作用,有效减缓了因腰椎融合术导致的邻近节段的加速退变。     

Junction kinematics between proximal mobile and distal fused lumbar segments: biomechanical analysis of pedicle and hook constructs

Background contextBiomechanical studies have demonstrated increased motion in motion segments adjacent to instrumentation or arthrodesis. The effects of different configurations of hook and pedicle screw instrumentation on the biomechanical behaviors of adjacent segments have not been well documented.PurposeTo compare the effect of three different fusion constructs on adjacent segment motion proximal to lumbar arthrodesis.MethodsSeven human cadaver lumbar spines were tested in the following conditions: 1) intact; 2) L4–L5-simulated circumferential fusion (CF); 3) L4–L5-simulated fusion extended to L3 with pedicle screws; and 4) L4–L5-simulated fusion extended to L3 with sublaminar hooks. Rotation data at L2–L3, L3–L4, and L4–L5 were analyzed using both load limit control (±7.5 N·m) and displacement limit control (truncated to the greatest common angular motion of the segments for each specimen).ResultsBoth the L3–L4 and L2–L3 motion segments above the L4–L5-simulated CF had significantly increased motion in all loading planes compared with the intact spine, but no significant differences were found between L3–L4 and L2–L3 motion. When the L3–L4 segment was stabilized with pedicle screws, its motion was significantly smaller in flexion, lateral bending, and axial rotation than when stabilized with sublaminar hooks. At the same time, L2–L3 motion was significantly larger in flexion, lateral bending, and axial rotation in the pedicle screw model compared with the sublaminar hook construct.ConclusionsThe use of sublaminar hooks to stabilize the motion segment above a circumferential lumbar fusion reduced motion at the next cephalad segment compared with a similar construct using pedicle screws. The semiconstrained hook enhancement may be considered if a patient is at a risk of adjacent segment disorders.     

Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis

There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4–8) in the L5 group and 6.09 (range 4–9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7° before surgery to 6.8° after surgery in the L5 group, and from 22.8° to 7.7° in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at L5-S1 and loosening of L5 screws. Seven of the nine patients showed preoperative sagittal imbalance and/or lumbar hypolordosis, which might be risk factors of complications at L5-S1. For the patients with sagittal imbalance and lumbar hypolordosis, L5-S1 should be included in the fusion even if L5-S1 disc was minimal degeneration.     

体重指数对微创手术治疗单节段腰椎管狭窄症并腰椎不稳疗效的影响

目的:探讨体重指数(BMI)对微创减压经椎间孔腰椎间融合术联合经皮椎弓根螺钉内固定术治疗单节段腰椎管狭窄症并腰椎不稳的疗效的影响。方法:对2010年3月~2011年3月57例微创通道下行减压经椎间孔腰椎椎间融合术联合经皮椎弓根螺钉内固定手术治疗的单节段腰椎管狭窄症并腰椎不稳患者进行回顾性分析,按患者BMI不同分为3组,A组:正常体重组(BMI<25kg/m2),男14例,女17例;B组:超重组(25kg/m2≤BMI<30kg/m2),男7例,女12例;C组:肥胖组(BMI≥30kg/m2),男3例,女4例。记录每组患者手术时间、术中出血量、术后住院时间、手术并发症情况;术前、术后6个月及末次随访时行JOA评分(29分法)、Oswestry功能障碍指数(ODI)评定;末次随访时根据Bridwell椎间融合标准评价各组融合情况。年龄、性别构成比、术前JOA评分与ODI及随访时间3组之间无统计学差异(P>0.05),比较3组疗效。结果:3组患者手术时间有统计学差异(P<0.05),术中出血量及术后住院时间无统计学差异(P>0.05)。A组及C组各有1例术中硬膜囊撕裂;B组1例骨质疏松患者行椎间融合时融合器打入上位椎体中,术中取出融合器,予椎体间自体骨植骨融合;术后4例(A组1例,B组1例,C组2例)患者出现切口愈合不良,经抗生素及换药等治疗术后15~18d切口愈合。随访8～20个月,3组患者术后6个月及末次随访时JOA评分及ODI均较术前明显改善(P<0.05),术后6个月及末次随访时JOA评分及ODI 3组之间均无统计学差异(P>0.05);末次随访时,根据JOA评分计算临床改善率并评估手术疗效,其中A组优25例,良5例,可1例;B组优12例,良7例;C组优4例,良3例;3组优良率无统计学差异(P>0.05)。末次随访时,A、B及C组融合率分别为93.5%、94.7%和100%,3组之间无统计学差异(P>0.05);无融合器沉降、移位或塌陷,无螺钉断裂及松动。结论:微创减压经椎间孔腰椎椎间融合术联合经皮椎弓根螺钉内固定手术是治疗单节段腰椎管狭窄症并腰椎不稳的一种较好手术方法,BMI对其疗效无明显影响。     

Contoured Harrington instrumentation in the treatment of unstable spinal fractures. The effect of supplementary sublaminar wires

Twenty-nine patients with major fractures and fracture-dislocations of the thoracic and lumbar spine were treated by spinal fusion and contoured Harrington distraction instrumentation. Two groups of patients were identified. Group I (16 patients) had sublaminar wires. Group II (13 patients) had no wiring. Satisfactory alignment was achieved in all patients. There were several complications in both groups. None of the patients in Group I had postoperative cast immobilization. The addition of sublaminar wiring appears to eliminate the need for rigid external immobilization and is beneficial only for patients who cannot tolerate body casts. This technique is a disadvantage, however, when a short-length fusion is desired.     

腰椎经后路椎体间融合后单边或双边固定对邻近节段退变的影响

背景：在行后路椎体融合内固定术中,椎弓根钉置入不可避免会损伤邻近关节突关节。目前一致认为单边固定因保留一侧关节突关节可明显降低邻近节段退变的发生率,但仍缺乏对邻近节段退变的影响因素及不同节段退变发生率的长期随访研究。目的：对比经后路椎体间融合术（posterior lumbar interbody fusion,PLIF）后单边或双边椎弓根螺钉固定对邻近节段退变的影响。方法：2006年2月至2007年12月,101例行PLIF手术的L4-L5椎间盘突出症患者纳入本研究。采用单边固定42例,双边固定59例。所有患者术后随访时间均超过5年。邻近节段分为三个节段：第1个近端邻近节段、第2个近端邻近节段及远端邻近节段。依据末次随访的影像学资料评估邻近节段退变的情况,并记录末次随访时的ODI评分评价腰椎功能。结果：单边固定组第1个近端邻近节段、第2个近端邻近节段及远端邻近节段退变的发生率分别为57.1%（24/42）、45.2%（19/42）、38.1%（16/42）;双边固定组第1个近端邻近节段、第2个近端邻近节段及远端邻近节段退变的发生率分别为72.9%（43/59）、68.0%（40/59）、50.8%（30/59）。两组第1个近端邻近节段和远端邻近节段退变发生率无统计学差异,而第2个近端邻近节段退变发生率具有统计学差异。末次随访时单边固定组和双边固定组的ODI评分分别为25.6±5.9、28.4±5.2,两组具有显著统计学差异（t=-2.503,P=0.014）。结论：对于行腰椎后路减压融合术的单节段腰椎间盘突出症患者,单边固定者邻近节段退变发生率低于双边固定者,尤其对于第2个近端邻近退变节段的患者。     

Estimating the risk for symptomatic adjacent segment degeneration after lumbar fusion: analysis from a cohort of patients undergoing revision surgery

Purpose

Aim of this study is to estimate the risk for symptomatic adjacent segment degeneration (ASD) and examine the association between spino-pelvic parameters and ASD.

Methods

22 patients operated upon by instrumented lumbar or lumbosacral spinal fusion and re-operated upon for ASD were enrolled in the study. 83 consecutive patients with the same surgery and never re-operated upon were the controls. Pelvic incidence, sacral slope (SS), pelvic tilt (PT), and lumbar lordosis were calculated.

Results

Patients with ASD had significantly lower SS (p = 0.005) and higher PT values (p < 0.001). Patients with SS <39° or PT >21°, were at higher risk for symptomatic ASD (relative risk 1.73 for SS and 3.663 for PT).

Conclusions

In patients re-operated upon for ASD, pelvic retroversion and hyperlordosis are the main mechanisms of compensation for the unbalanced spine. Patients with PT above 21° and SS below 39° are at higher risk for symptomatic ASD.

     

类风湿关节炎合并腰椎退行性疾病患者腰椎椎间融合术后邻近节段退行性变的相关因素

目的探讨类风湿关节炎(RA)合并腰椎退行性疾病患者腰椎椎间融合术后发生邻近节段退行性变(ASD的危险因素。方法回顾性分析2008年1月—2016年12月收治的55例RA合并腰椎退行性疾病患者的临床资料,其中29例采用减压并椎间融合术(融合组)治疗,26例采用单纯减压术(非融合组)治疗。记录手术前后红细胞沉降率(ESR)、C反应蛋白(CRP)、基质金属蛋白酶-3(MMP-3)等指标,采用28个关节疾病活动度评分联合CRP水平(DAS28-CRP)评估RA活动度;采用日本骨科学会(JOA)评分评估患者神经功能;测量X线片上腰椎邻近节段头端椎间隙狭窄及椎体滑脱程度以评估ASD情况。运用多因素logistic回归分析检验术后继发ASD的危险因素。结果所有手术顺利完成,术后随访1.5～6.0年,平均3.2年。2组术后JOA评分较术前均明显改善,且融合组显著高于非融合组,差异均有统计学意义(P 0.05)。融合组手术翻修率、影像学ASD及症状性ASD发生率显著高于非融合组,差异均有统计学意义(P 0.05)。多因素logistic回归分析显示,DAS28-CRP评分 4.7分、术前血清MMP-3含量升高是术后继发ASD的独立危险因素。结论 RA合并腰椎退行性疾病患者采用腰椎减压并椎间融合术治疗后出现ASD和需行翻修手术的风险高于采用单纯减压术治疗的患者,术前血清MMP-3含量和DAS28-CRP评分升高可能与腰椎椎间融合术后ASD的发生相关。     

Bryan人工间盘置换与前路减压融合治疗颈椎退行性疾病的中期随访研究

 目的 评价人工椎间盘置换术治疗颈椎退行性疾病的中期疗效,并探讨其是否可以减少邻近节段退变的发生。方法 前瞻性对比分析接受颈椎人工间盘置换术(置换组,45例)与颈椎前路减压融合术(融合组,48例)治疗的颈椎退行性疾病患者的随访6年临床疗效和影像学资料。临床疗效评价指标为日本骨科协会评分(Japanese Orthopaedic Association Scores,JOA)、颈椎功能残障指数量表(neck disability index,NDI)和Odom评分。影像学评价指标为矢状位曲度、活动度、邻近节段退变。结果28例置换组患者和35例融合组患者完成随访。两组患者末次随访的JOA评分和NDI均较术前有明显改善,组间比较差异无统计学意义。92.9%的置换组患者和97.1%的融合组患者Odom评分获得很好或较好的结果。两组患者颈椎矢状位曲度末次随访较术前均得到保持。颈椎整体活动度置换组末次随访与术前无明显差异,而融合组则是明显降低。置换组置换节段活动度术前为9.5°±3.7°,术后3个月为7.0°±3.0°,末次随访为6.6°±4.1°,末次随访较术后3个月无明显改变。邻近节段退变评估采用侧位X线片和MRI T2加权像,置换组上、下邻近节段退变均明显少于融合组。结论 Bryan人工椎间盘置换术6年的随访结果基本满意,能更好地保留颈椎生理活动及生物力学环境,从而降低邻近节段退变的发生率。