Correlation between disability and MRI findings in lumbar spinal stenosis: a prospective study of 109 patients operated on by decompression

Background and purpose

MRI is the modality of choice when diagnosing spinal stenosis but it also shows that stenosis is prevalent in asymptomatic subjects over 60. The relationship between preoperative health-related quality of life, functional status, leg and back pain, and the objectively measured dural sac area in single and multilevel stenosis is unknown. We assessed this relationship in a prospective study.

Patients and methods

The cohort included 109 consecutive patients with central spinal stenosis operated on with decompressive laminectomy or laminotomy. Preoperatively, all patients completed the questionnaires for EQ-5D, SF-36, Oswestry disability index (ODI), estimated walking distance and leg and back pain (VAS). The cross-sectional area of the dural sac was measured at relevant disc levels in mm², and spondylolisthesis was measured in mm. For comparison, the area of the most narrow level, the number of levels with dural sac area < 70 mm², and spondylolisthesis were studied.

Results

Before surgery, patients with central spinal stenosis had low HRLQoL and functional status, and high pain levels. Patients with multilevel stenosis had better general health (p = 0.04) and less leg and back pain despite having smaller dural sac area than patients with single-level stenosis. There was a poor correlation between walking distance, ODI, the SF-36, EQ-5D, and leg and back pain levels on the one hand and dural sac area on the other. Women more often had multilevel spinal stenosis (p = 0.05) and spondylolisthesis (p < 0.001). Spondylolisthetic patients more often had small dural sac area (p = 0.04) and multilevel stenosis (p = 0.06).

Interpretation

Our findings indicate that HRQoL, function, and pain measured preoperatively correlate with morphological changes on MRI to a limited extent.MRI plays a central role in the diagnosis of spinal stenosis. Despite this, the correlation between MRI characteristics and clinical symptoms remains elusive as a considerable number of asymptomatic subjects have MRI-verified spinal stenosis (Boden et al. 1990). The relationship between the hard pathomorphological data as seen on MRI and the more subjective data from accepted outcome tools in terms of HRLQoL, functional status, and pain is unknown but is clinically relevant.The absolute reduced cross-sectional area that gives neurological symptoms of central spinal stenosis has been estimated to be around 75 mm² (critical size) (Schönström 1988) and some studies today use a value of 70–80 mm² as a definition of spinal stenosis (Malmivaara et al. 2007). Since MRI is used for the preoperative planning, any correlation between MRI findings and preoperative symptoms and disability would be of interestWe therefore investigated the relationship between the minimal dural sac area (mm²), number of levels with stenosis, and spondylolisthesis in relation to preoperative subjective measures of disease in terms of: self reported walking distance, the visual analog scale (VAS) for leg and back pain, Oswestry disability index, the 4 physical domains of the SF-36, and the EQ-5D.     

Health-related quality of life following decompression compared to decompression and fusion for degenerative lumbar spondylolisthesis: a Canadian multicentre study

Background

Decompression alone (D) is a well-accepted treatment for patients with lumbar spinal stenosis (LSS) causing neurogenic claudication; however, D is controversial in patients with LSS who have degenerative spondylolisthesis (DLS). Our goal was to compare the outcome of anatomy-preserving D with decompression and fusion (DF) for patients with grade I DLS. We compared patients with DLS who had elective primary 1–2 level spinal D at 1 centre with a cohort who had 1–2 level spinal DF at 5 other centres.

Methods

Patients followed for at least 2 years were included. Primary analysis included comparison of change in SF-36 physical component summary (PCS) scores and the proportion of patients achieving minimal clinically important difference (MCID) and substantial clinical benefit (SCB).

Results

There was no significant difference in baseline SF-36 scores between the groups. The average change in PCS score was 10.4 versus 11.4 (p = 0.61) for the D and DF groups, respectively. Sixty-seven percent of the D group and 71% of the DF group attained MCID, while 64% of both D and DF groups attained SCB. There was no significant difference between D and DF for change in PCS score (p = 0.74) or likelihood of reaching MCID (p = 0.81) or SCB (p = 0.85) after adjusting for other variables.

Conclusion

In select patients with DLS, the outcome of D is comparable to DF at a minimum of 2 years.     

Effects of zoledronic acid on bone fusion in osteoporotic patients after lumbar fusion

Summary

Treatment with zoledronic acid in osteoporotic patients with spinal fusion shortens the duration of time to fusion, improves the fusion rate, prevents the subsequent adjacent vertebral compression fractures, improves the clinical outcomes, and prevents immobilization-induced bone loss in the hip.

Introduction

The objective of the study was to explore the effects of zoledronic acid on the healing process in osteoporotic patients following spinal fusion in a randomized, placebo-controlled, and triple-blinded study.

Methods

Seventy-nine osteoporotic patients with single-level degenerative spondylolisthesis were randomly assigned to receive either zoledronic acid infusion (zoledronic acid group) or saline infusion (controls) after spinal fusion. Functional radiography and CT scans were used to evaluate fusion status. Bone formation was graded into three categories: Grade A (bridging bone bonding with adjacent vertebral bodies), Grade B (bridging bone bonding with either superior or inferior vertebral body), or Grade C (incomplete bony bridging). A solid fusion was defined as less than 5° of angular motion with Grade A or B bone formation. Adjacent vertebral compression fractures (VCF) were assessed on MRI at 12 months after surgery. Serum level of carboxy terminal cross-linked telopeptide of type I collagen (β-CTX) and amino-terminal propeptide of type I procollagen (PINP) was measured. Bone mineral density (BMD) was measured by DXA. Oswestry Disability Index (ODI) was used to assess the clinical outcomes.

Results

Grade A or B bridging bone was more frequently observed in zoledronic acid group at 3, 6, and 9 months post-operation compared to the control group (p?<?0.05). At 12?-months post-operation, bridging bone and solid fusion were not significantly different between groups. No patients in zoledronic acid group showed aVCF, whereas six patients (17 %) in the control group did (p?<?0.05). Both β-CTX and PINP were suppressed in zoledronic acid group. BMD at the femoral neck decreased rapidly and did not return to the preoperative level in the controls at 3 (?1.4 %), 6 (?2.5 %), and 12 (?0.8 %) months after surgery. Zoledronic acid prevented this immobilization-induced bone loss and increased BMD. ODI showed the improved clinical outcomes compared with controls at 9 and 12 months post-surgery.

Conclusion

Treatment with zoledronic acid in osteoporotic patients with spinal fusion shortens the time to fusion, improves the fusion rate, prevents subsequent aVCFs, and improves clinical outcomes.

     

Unilateral versus bilateral instrumented transforaminal lumbar interbody fusion in two-level degenerative lumbar disorders: a prospective randomised study

Purpose

The aim of this study was to analyse the clinical and radiological outcomes of unilateral versus bilateral instrumented TLIF in two-level degenerative lumbar disorders.

Methods

A prospective randomised clinical study was performed from January 2008 to May 2011. Sixty-eight consecutive patients with severe low back pain and radicular pain were divided randomly into the unilateral (n = 33) or bilateral (n = 35) pedicle screw fixation group based on a random number list. Operative time, blood loss, duration of hospital stay, fusion rate, complication rate and implant costs were recorded and analysed statistically. Visual analog scale (VAS) scores, Oswestry Disability Index (ODI), and SF-36 were used to assess the preoperative and postoperative clinical results in the two groups.

Results

No differences were observed between the two groups with respect to demographic data. The patients of the two groups had significant improvement in functional outcome compared to preoperatively. There was no significant difference comparing fusion rate, complication rate and duration of hospital stay between the two groups at postoperative follow-up (P > 0.05). However, compared with the bilateral pedicle screw group, a significant decrease occurred in operative time, blood loss and implant costs in the unilateral group.

Conclusion

Two-level unilateral instrumented TLIF is an effective and safe method with reduced operative time and blood loss for multiple-level lumbar diseases. But it is imperative that the larger cage should be appropriately positioned to support the contralateral part of the anterior column by crossing the midline of the vertebral body.     

两种术式治疗3节段退变性腰椎管狭窄症早期疗效比较

目的比较后路椎体间融合术(PLIF)与微创通道辅助下经椎间孔入路腰椎椎间融合术(MIS-TLIF)治疗3节段退变性腰椎管狭窄症的早期疗效。方法按手术方式不同,将60例3节段退变性腰椎管狭窄症患者分为PLIF组(36例)和MIS-TLIF组(24例),比较两组手术时间、术中出血量、住院时间和随访时腰背疼痛VAS评分、下肢疼痛VAS评分、ODI评分、SF-36评分以及术后并发症。结果患者均获得随访,PLIF组随访12~20个月,MIS-TLIF组随访13~21个月。手术时间、术中出血量、住院时间两组比较差异均有统计学意义(P<0.05)。腰背疼痛VAS评分、下肢疼痛VAS评分、SF-36评分、ODI评分两组术后6、12个月与术前比较差异均有统计学意义(P<0.05)。术后6、12个月下肢疼痛VAS评分、SF-36评分、ODI评分两组比较差异均无统计学意义(P>0.05)。腰背疼痛VAS评分术后6个月两组比较差异有统计学意义(P<0.05),但术后12个月两组比较差异无统计学意义(P>0.05)。PLIF组发生脑脊液漏3例,MIS-TLIF组发生脑脊液漏1例、浅表手术部位感染2例,两组并发症例数比较差异无统计学意义(P>0.05)。影像学显示,两组患者手术节段均在术后1年内获得良好的节段融合。结论与PLIF比较,MIS-TLIF治疗3节段退变性腰椎管狭窄症出血量少、住院时间短、术后腰背疼痛症状改善速度快。     

Volume and Contact Surface Area Analysis of Bony Tunnels in Single and Double Bundle Anterior Cruciate Ligament Reconstruction Using Autograft Tendons: In Vivo Three-Dimensional Imaging Analysis

Background

Regarding reconstruction surgery of the anterior cruciate ligament (ACL), there is still a debate whether to perform a single bundle (SB) or double bundle (DB) reconstruction. The purpose of this study was to analyze and compare the volume and surface area of femoral and tibial tunnels during transtibial SB versus transportal DB ACL reconstruction.

Methods

A consecutive series of 26 patients who underwent trantibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft from January 2010 to October 2010 were included in this study. Three-dimensional computed tomography (3D-CT) was taken within one week after operation. The CT bone images were segmented with use of Mimics software v14.0. The obtained digital images were then imported in the commercial package Geomagic Studio v10.0 and SketchUp Pro v8.0 for processing. The femoral and tibial tunnel lengths, diameters, volumes and surface areas were evaluated. A comparison between the two groups was performed using the independent-samples t-test. A p-value less than the significance value of 5% (p < 0.05) was considered statistically significant.

Results

Regarding femur tunnels, a significant difference was not found between the tunnel volume for SB technique (1,496.51 ± 396.72 mm³) and the total tunnel volume for DB technique (1,593.81 ± 469.42 mm³; p = 0.366). However, the total surface area for femoral tunnels was larger in DB technique (919.65 ± 201.79 mm²) compared to SB technique (810.02 ± 117.98 mm²; p = 0.004). For tibia tunnels, there was a significant difference between tunnel volume for the SB technique (2,070.43 ± 565.07 mm³) and the total tunnel volume for the DB technique (2,681.93 ± 668.09 mm³; p ≤ 0.001). The tibial tunnel surface area for the SB technique (958.84 ± 147.50 mm²) was smaller than the total tunnel surface area for the DB technique (1,493.31 ± 220.79 mm²; p ≤ 0.001).

Conclusions

Although the total femoral tunnel volume was similar between two techniques, the total surface area was larger in the DB technique. For the tibia, both total tunnel volume and the surface area were larger in DB technique.     

A cost-utility analysis of Dynesys dynamic stabilization versus instrumented fusion for the treatment of degenerative lumbar spine diseases

Background

Symptomatic chronic low back and leg pain resulting from lumbar spine degenerative disorders is highly prevalent in China, and for some patients, surgery is the final option for improvement. Several techniques for spinal non-fusion have been introduced to reduce the side-effects of fusion methods and hasten postoperative recovery. In this study, the authors have evaluated the cost-effectiveness of Dynesys posterior dynamic stabilization system (DY) compared with lumbar fusion techniques in the treatment of single-level degenerative lumbar spinal conditions.

Lumbar instrumented posterolateral fusion in spondylolisthetic and failed back patients: a long-term follow-up study spanning 11–13?years

Introduction and materials

We examined lumbar transpedicular instrumented posterolateral fusion patients operated on between 1992 and 1997 presenting: degenerative spondylolisthesis with spinal stenosis; adult isthmic spondylolisthesis; failed back syndrome after one to five discectomies; and failed back syndrome after one to three laminectomy operations (Groups 1–4, respectively).

Methods

They were examined by an independent orthopedic surgeon, completed the Oswestry Disability Index (ODI) and visual analog scale (VAS) questionnaires and their outcome was evaluated.

Results

The overall patient satisfaction at follow-up (mean 11.7 years) was 82.1 %. The reoperation rate was 15.1 % (7.5 % due to adjacent segment disease).

Conclusion

Group 1 showed the greatest improvements in ODI and VAS values, Group 2 the lowest and Group 3 the highest preoperative values, and Group 4 the second highest improvements. Patient satisfaction scores were 90.3, 69.7, 63.6 and 80.0 %, respectively, and unplanned reoperation rates were 6.5, 9.1, 31.8 and 20.0 %. Thus, long-term outcomes of lumbar instrumented posterolateral fusion (rarely previously studied) were satisfactory for >80 % of patients, but varied among groups.     

Efficacy of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in posterolateral lumbar fusion: an open,active-controlled,randomized, multicenter trial

Background Context

The efficacy and safety of recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute in spinal fusion has been widely researched. However, no study of the efficacy and safety of Escherichia coli-derived rhBMP-2 (E.BMP-2) with a hydroxyapatite (HA) carrier has been proposed.

Comparison of Functional Outcomes following Surgical Decompression and Posterolateral Instrumented Fusion in Single Level Low Grade Lumbar Degenerative versus Isthmic Spondylolisthesis

Background

The two most common types of surgically treated lumbar spondylolisthesis in adults include the degenerative and isthmic types. The aim of this study was to compare the functional outcomes of surgical decompression and posterolateral instrumented fusion in patients with lumbar degenerative and isthmic spondylolisthesis.

Methods

In this retrospective study, we reviewed the clinical outcomes in surgically treated patients with single level, low grade lumbar degenerative, and isthmic spondylolisthesis (groups A and B, respectively) from August 2007 to April 2011. We tried to compare paired settings with similar initial conditions. Group A included 52 patients with a mean age of 49.2 ± 6.1 years, and group B included 52 patients with a mean age of 47.3 ± 7.4 years. Minimum follow-up was 24 months. The surgical procedure comprised neural decompression and posterolateral instrumented fusion. Pain and disability were assessed by a visual analog scale (VAS) and the Oswestry Disability Index (ODI), respectively. The Wilcoxon and Mann-Whitney U-tests were used to compare indices.

Results

The most common sites for degenerative and isthmic spondylolisthesis were at the L4-L5 (88.5%) and L5-S1 (84.6%) levels, respectively. Surgery in both groups significantly improved VAS and ODI scores. The efficacy of surgery based on subjective satisfaction rate and pain and disability improvement was similar in the degenerative and isthmic groups. Notable complications were also comparable in both groups.

Conclusions

Neural decompression and posterolateral instrumented fusion significantly improved pain and disability in patients with degenerative and isthmic spondylolisthesis. The efficacy of surgery for overall subjective satisfaction rate and pain and disability improvement was similar in both groups.     

Semi-Circumferential Decompression: Microsurgical Total en-bloc Ligamentum Flavectomy to Treat Lumbar Spinal Stenosis with Grade I Degenerative Spondylolisthesis

Background

To describe and assess clinical outcomes of the semi-circumferential decompression technique for microsurgical en-bloc total ligamentum flavectomy with preservation of the facet joint to treat the patients who have a lumbar spinal stenosis with degenerative spondylolisthesis.

Methods

We retrospectively analyzed the clinical and radiologic outcomes of 19 patients who have a spinal stenosis with Meyerding grade I degenerative spondylolisthesis. They were treated using the "semi-circumferential decompression" method. We evaluated improvements in back and radiating pain using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). We also evaluated occurrence of spinal instability on radiological exam using percentage slip and slip angle.

Results

The mean VAS score for back pain decreased significantly from 6.3 to 4.3, although some patients had residual back pain. The mean VAS for radiating pain decreased significantly from 8.3 to 2.5. The ODI score improved significantly from 25.3 preoperatively to 10.8 postoperatively. No significant change in percentage slip was observed (10% preoperatively vs. 12.2% at the last follow-up). The dynamic percentage slip (gap in percentage slip between flexion and extension X-ray exams) did not change significantly (5.2% vs. 5.8%). Slip angle and dynamic slip angle did not change (3.2° and 8.2° vs. 3.6° and 9.2°, respectively).

Conclusions

The results suggested that semi-circumferential decompression is a clinically recommendable procedure that can improve pain. This procedure does not cause spinal instability when treating patients who have a spinal stenosis with degenerative spondylolisthesis.     

Long fusions to the sacrum in elderly patients with spinal deformity

Purpose

Long spinal deformity fusions in elderly patients continue to be controversial. However, there is a growing population of elderly patients with spinal deformities that may be optimally treated by reconstructive surgery requiring a long fusion to the sacrum. This study evaluated clinical outcomes in elderly (>65) adult deformity patients who underwent posterior instrumented reconstruction consisting of fusion from the thoracic spine to the sacrum with iliac fixation.

Methods

Patients in a prospective database for adult spinal deformity who had a posterior reconstruction with an instrumented fusion from the thoracic spine to the sacrum that included iliac fixation with minimum 2-year follow-up were identified. Two cohorts were compared: patients 65 years and older and patients 55 years and younger. Student’s t test for independent groups was used to determine any significant differences between continuous variables. Chi-square was used to compare categorical demographic variables between the two groups.

Results

The 65 and older group consisted of 15 patients with an average age of 71 years (range 65–78 years). The 55 and younger group consisted of 25 patients with an average age of 45 years (range 30–55 years). The older group had a worse mean co-morbidity score (4.6 vs. 2.1). Baseline SRS scores were similar between groups. Baseline SF-12 data showed worse PCS (22.1 vs. 32.0, p = 0.009) yet better MCS (63.6 vs. 48.4, p < 0.0001) in the older group. Although major curve magnitude was similar (47.1° vs. 42.6°), the older group had more positive sagittal imbalance at baseline (115.7 vs. 54.2 mm, p = 0.02). Number of levels fused, operative time, blood loss, and incidence of complications were similar between groups. Two-year improvements in SRS subscores, SF-12 PCS, and MCS were not significantly different between groups.

Conclusions

Properly selected patients 65 years of age and older who have substantial sagittal imbalance, a considerable disease burden, and a lesser degree of mental distress can obtain as much clinical benefit as their younger counterparts (≤55 years of age) 2 years following spinal deformity surgery that requires fusion from the thoracic spine to the sacrum with segmental instrumentation and iliac fixation.     

Posterolateral versus circumferential instrumented fusion for monosegmental lumbar degenerative disc disease using an expandable cage

Background

Theoretically, 360° instrumented fusion has been considered to offer better radiological correction than PLF. Despite numerous publications, this correlation is still weak with several controversies in the relative literature.

Purpose

This prospective randomized study was designed to compare the radiological segmental results, complications and outcome of 360° instrumented fusion with the use of a single diagonal expandable PLIF device versus posterolateral pedicle screw fixation in monosegmental lumbar DDD and to show that the use of an novel expandable cage is associated with low PLIF-related complication rate compared to conventional cages reported previously.

Study design

Prospective randomized controlled clinical and radiological study.

Patient sample

Adults who suffered from monosegmental DDD were eligible for enrolment in this trial. We randomly assigned 150 patients to receive either 360° instrumented fusion (group A) with expandable cage or PLF (group B).

Outcome measures

Differences between the two groups regarding clinical parameters and radiographic sagittal measurements after 36?months of follow-up.

Methods

The record included global [T12-S1 lordosis, sagittal global spinal balance (SB) (C7-mid-femoral axis)] and segmental [segmental disc wedging (SDW), anterior (ADHr) and posterior (PDHr) disc height ratio] radiological measurements at the instrumented segment. Additionally, clinical outcome was evaluated with VAS, SF-36 (Physical function and Bodily Pain) and ODI questionnaires. Fusion was evaluated with the use of Christiansen method.

Results

In 73 and 72 participants of group A and B, respectively, who completed follow-up to 36?months, there were no differences with respect to the rate of improvement in SF-36, ODI and VAS scores. However, in the spines of group A, there was a significant increase in anterior disc height ratio (P?=?0.0057), posterior disc height (P?=?0.016) and segmental disc wedging (P?=?0.00021) without subsequent loss of correction. Fusion rate was radiologically shown in 94.5% and 87% spines of group A and B, respectively (P?>?0.2). Four and 9 spines in group A and B, respectively, showed non-union at the final observation.

Conclusions

Our findings suggest that 360° fusion offers better sagittal radiological restoration associated with circumferential fusion. However, this difference seemed not to have any medium-term clinical impact. The use of expandable cage was associated with low PLIF-related complications compared to conventional cages.     

Effect of zoledronic acid in an L6–L7 rabbit spine fusion model

Previous studies have shown that zoledronic acid administration can increase mineral content and strength in distraction osteogenesis. Of the few studies that have examined the use of bisphosphonates in spinal arthrodesis, none have assessed the effect of single dose treatment. The objective of this study was to evaluate the feasibility of enhancing spinal fusion rate using single dose zoledronic acid (ZA) to increase fusion-mass size and mineral density. Forty-eight New Zealand white rabbits underwent an L6–L7 intertransverse process fusion. The L6–L7 model is more challenging than the more commonly used level of L5–L6. Animals were randomly allocated to one of three groups, one received iliac crest bone graft alone, one group received iliac crest bone graft with locally administered zoledronic acid, 20 μg, and one group received iliac crest bone graft with a single dose of systemically administered zoledronic acid, 0.1 mg/kg. ZA doses were administered at the time of surgery. Twenty-four rabbits were culled at 6 weeks and 24 rabbits were culled at 12 weeks. Success of spinal fusion was determined by manual palpation. Specimens were evaluated radiographically, underwent quantitative computerised tomography analysis and were tested biomechanically in flexion and extension. In the six-week group, only five of the 24 spines fused with no noticeable trend with respect to treatment. In the 12-week group there was a trend toward increased fusion in the systemically administered ZA group (63%) versus the other two groups (25%) but was not statistically significant (p = 0.15). Radiographically, the local ZA treatment group showed a delay in remodelling with the presence of unremodelled bone chips. The 12-week systemic ZA group exhibited an 86% increase in BMC, a 31% increase in vBMD and a 41% increase in the volume of the fusion-mass (p < 0.05). The 12-week local ZA group also showed significant increases in BMC (69%), vBMD (31%) and total fusion-mass volume (29%) (p < 0.05). Biomechanical testing showed that the range of motion in flexion decreased to 4.5 (±2.5) degrees and 4.8 (±4.7) degrees for the local and systemic groups respectively compared to 9.6 (±4.9) degrees for the control group (p < 0.05). This study has shown that zoledronic acid increased fusion-mass size and bone mineral content. Systemic ZA led to an increased fusion rate; however the fusion rate remained below 100%. We suggest that bisphosphonate treatment may require an anabolic conjunctive therapy to ensure enhanced successful fusion.     

Comparison of unilateral versus bilateral pedicle screw fixation in degenerative lumbar diseases: a meta-analysis

Purpose

Traditionally, lumbar spinal surgery is performed with bilateral pedicle screw fixation to provide stability as the fusion heals. However, many studies have reported that unilateral pedicle screw fixation is as effective as bilateral constructs. To compare the clinical outcomes, complications, and surgical trauma between the two techniques for treatment of degenerative lumbar diseases, we conducted a meta-analysis.

Methods

We searched MEDLINE, EMBASE, PubMed, Google Scholar, and Cochrane databases for relevant controlled studies up to August 2013 that compared unilateral with bilateral fixation for the treatment of degenerative lumbar diseases. We independently performed title/abstract screening and full-text screening. A random effects model was used for heterogeneous data; otherwise, a fixed effect model was used, pooling data using mean difference (MD) for continuous outcomes and odds ratio (OR) for dichotomous outcomes.

Results

A total of 12 articles (865 participants) were eligible. Overall, there were significant differences between the two groups for blood loss (MD = ?171.73, 95 % CI = ?281.70 to ?61.76; p = 0.002), operation time (MD = ?66.02, 95 % CI = ?115.52 to ?16.51; p = 0.009), and fusion rate (OR = 0.50, 95 % CI = 0.26–0.96; p = 0.004). However, there were no significant differences in hospital stay (MD = ?4.44, 95 % CI = ?13.37 to 4.50), ODI (MD = ?0.09, 95 % CI = ?0.59 to 0.42; p = 0.74), JOA (MD = 0.18, 95 % CI = ?0.77 to 1.14; p = 0.71), VAS (MD = ?0.04, 95 % CI = ?0.16 to 0.08; p = 0.49), SF-36 (PF: MD = ?1.11, 95 % CI = ?4.38 to 2.17, p = 0.51; GH: MD = 1.22, 95 % CI = ?2.17 to 4.60, p = 0.48; MH: MD = ?0.22, 95 % CI = ?3.83 to 3.38, p = 0.90) and complications (OR = 1.15, 95 % CI = 0.72–1.85; p = 0.56).

Conclusions

This meta-analysis shows that there was significantly less blood loss in unilateral group and less operating time; however, the fusion rate was significantly higher in the bilateral group. The outcomes of hospital stay, ODI, JOA, VAS, SF-36 score, and complications are similar in the two groups.     

The clinical and radiological outcomes of multilevel minimally invasive transforaminal lumbar interbody fusion

Purpose

To investigate the clinical and radiological outcomes of multilevel minimally invasive transforaminal lumbar interbody fusion (MITLIF) in multilevel degenerative lumbar diseases.

Methods

Of 172 patients who could be followed-up for at least 1 year after undergoing a MITLIF, a total of 127 patients in whom unilateral cages were used through a unilateral approach (consisting of 69 patients for single-level, 40 for two-level, and 18 for three- or higher-level) were retrospectively studied as subjects. In this study, clinical assessment parameters included Visual Analog Scale (VAS) score and Oswestry Disability Index (ODI), while radiologic assessment parameters included disc height, segmental lordotic angle, and lumbar lordotic angle. At the last follow-up, the level of bone fusion was determined in accordance with the Brantigan and Steffee criteria for classification of fusion results.

Results

The VAS scores of back pain and radiating leg pain tended to improve postoperatively, and showed no significant difference among groups (p > 0.05). In terms of ODI, the results of functional assessments also indicated no significant difference among groups (p > 0.05). Similarly, there was no statistically significant difference in disc height, segmental lordotic angle, lumbar lordotic angle, and bone fusion depending on the number of fusion levels (p > 0.05).

Conclusions

Regardless of the number of fused levels, satisfactory clinical and radiological outcomes of MITLIF were seen in patients with spinal stenosis, which suggests that the said surgical procedure may be useful even for patients with multilevel spinal stenosis.     

A prospective randomized controlled study comparing the pain relief in patients with osteoporotic vertebral compression fractures with the use of vertebroplasty or facet blocking

Purpose

To compare the clinical and radiological outcomes of patients undergoing percutaneous vertebroplasty (PVP) versus those undergoing facet blocking (FB) for severe pain due to osteoporotic vertebral compression fractures (OVCFs).

Methods

Two hundred and six patients who had OVCFs on spine radiography and intractable back pain for ≤8 weeks were recruited between January 2009 and January 2013 (165 females and 41 males, age ≥55 years). Patients were randomly assigned to the PVP group (100 patients) or the FB group (106 patients). VAS, ODI, Roland Morris disability (RMD) scores, scores on the Standardized Physical Component of the SF-36 form (SPC) and scores on the Standardized Mental Component of the SF-36 form (SMC) were determined preoperatively and at each follow-up time (1 day, 1 week, 1, 3, 6, and 12 months). In addition, plain radiographs were obtained at 3, 6, and 12 months postoperatively to detect new fractures.

Results

Significantly lower VAS, ODI, and RMD scores for patients in the PVP group compared to those in the FB group were observed at follow-up of 1 day and 1 week (p < 0.05). However, differences in the VAS, ODI, RMD and SPC/MCS (SF-36) scores between the two groups at follow-ups of more than 1 month were statistically insignificant (p > 0.05). Difference in numbers of new fractures in the two groups at the follow-up of 12 months was also statistically insignificant.

Conclusions

PVP produced better pain relief than FB in the short term (≤1 week). However, the difference in pain-relief between these two techniques was insignificant in the long term (follow-up between 1 month and 12 months).

     

Bilateral decompression using a unilateral pedicle construct for lumbar stenosis

Purpose

To determine the effectiveness of bilateral decompression via a unilateral approach using unilateral pedicle screw fixation for two-level lumbar stenosis with instability.

Methods

Between October 2006 and October 2010, 98 patients (61 men and 37 women) who had reached the three-year follow-up interval were treated with unilateral pedicle screw fixation at the authors’ institution. All patients underwent two-level transforaminal lumbar interbody fusion (TLIF), and the mean age was 59.6 years (range, 40–72). Visual analog scale (VAS) scores and Oswestry Disability Index (ODI) were used to assess the pre-operative and postoperative clinical results. Fusion status, the disc space height, and the whole lumbar lordotic angle were analysed for the radiological evaluation.

Results

The ODI scores decreased significantly in both early and late follow-up evaluations and the visual analog scale (VAS) score demonstrated significant improvement in late follow-up (P < 0.01). The disc space height (P < 0.05) and the whole lumbar lordotic angle (P < 0.05) were increased at the final follow-up. Successful fusion was achieved in all patients.

Conclusion

Bilateral decompression via a unilateral approach using unilateral pedicle screw fixation for two-level lumbar stenosis with instability, which can maintain the lumbar lordosis and the disc space height, is an effective and less invasive method than with bilateral constructs.     

Five-year follow-up of total disc replacement compared to fusion: a randomized controlled trial

Purpose

To evaluate long-term clinical results of lumbar total disc replacement (TDR) compared with posterior lumbar fusion.

Methods

This prospective randomized controlled trial comprised 152 patients; 80 were randomized to TDR and 72 to fusion. All patients had chronic low back pain (CLBP) and had not responded to nonsurgical treatment. Primary outcome measure was global assessment of back pain (GA), secondary outcome measures were back and leg pain, Oswestry Disability Index (ODI), EQ5D, and SF-36. All measures were collected from SweSpine (Swedish national register for spinal surgery) at 1, 2, and 5 years. Follow-up rate at 5 years was 99.3 %.

Results

Both groups showed clinical improvement at 5-year follow-up. For GA, 38 % (30/80) in the TDR group were totally pain free vs. 15 % (11/71) in the fusion group (p < 0.003). Back pain and improvement of back pain were better in the TDR group: VAS back pain at 5 years 23 ± 29 vs. 31 ± 27, p = 0.009, and VAS improvement of back pain at 5 years 40 ± 32 vs. 28 ± 32, p = 0.022. ODI and improvement in ODI were also better in the TDR group: ODI at 5 years 17 ± 19 vs. 23 + 17, p = 0.02 and ODI improvement at 5 years 25 ± 18 vs. 18 ± 19 (p = 0.02). There was no difference in complications and reoperations between the two groups.

Conclusions

Global assessment of low back pain differed between the two surgical groups at all follow-up occasions. Significant differences between groups concerning back pain, pain improvement, and ODI were present at 1 year and disappeared at 2 years, but reappeared at the 5-year follow-up.     

The Relationship between Spinal Stenosis and Neurological Outcome in Traumatic Cervical Spine Injury: An Analysis using Pavlov's Ratio, Spinal Cord Area, and Spinal Canal Area

Background

This study examined the relationship between four radiological parameters (Pavlov''s ratio, sagittal diameter, spinal cord area, and spinal canal area) in patients with a traumatic cervical spine injury, as well as the correlation between these parameters and the neurological outcome.

Methods

A total of 212 cervical spinal levels in 53 patients with a distractive-extension injury were examined. The following four parameters were measured: Pavlov''s ratio on the plain lateral radiographs, the sagittal diameter, the spinal cord area, and the spinal canal area on the MRI scans. The Pearson correlation coefficients between the parameters at each level and between the levels of each parameter were evaluated. The correlation between the radiological parameters and the spinal cord injury status classified into four categories, A (complete), B (incomplete), C (radiculopathy), and D (normal) was assessed.

Results

The mean Pavlov''s ratio, sagittal diameter, spinal cord area and spinal canal area was 0.84, 12.9 mm, 82.8 mm² and 236.8 mm², respectively. An examination of the correlation between the radiological spinal stenosis and clinical spinal cord injury revealed an increase in the values of the four radiological parameters from cohorts A to D. Pavlov''s ratio was the only parameter showing statistically significant correlation with the clinical status (p = 0.006).

Conclusions

There was a correlation between the underlying spinal stenosis and the development of neurological impairment after a traumatic cervical spine injury. In addition, it is believed that Pavlov''s ratio can be used to help determine and predict the neurological outcome.