Reliability of thoracolumbar burst fracture classification in the Swedish Fracture Register.

BACKGROUND: The Swedish Fracture Register (SFR) is a national quality register for all types of fractures in Sweden. Spine fractures have been included since 2015 and are classified using a modified AOSpine classification. The aim of this study was to determine the accuracy of the classification of thoracolumbar burst fractures in the SFR. METHODS: Assessments of medical images were conducted in 277 consecutive patients with a thoracolumbar burst fracture (T10-L3) identified in the SFR. Two independent reviewers classified the fractures according to the AOSpine classification, with a third reviewer resolving disagreement. The combined results of the reviewers were considered the gold standard. The intra- and inter-rater reliability of the reviewers was determined with Cohen's kappa and percent agreement. The SFR classification was compared with the gold standard using positive predictive values (PPV), Cohen's kappa and percent agreement. RESULTS: The reliability between reviewers was  high (Cohen's kappa 0.70-0.97). The PPV for correctly classifying burst fractures in the SFR was high irrespective of physician experience (76-89%), treatment (82% non-operative, 95% operative) and hospital type (83% county, 95% university). The inter-rater reliability of B-type injuries and the overall SFR classification compared with the gold standard was low (Cohen's kappa 0.16 and 0.17 respectively). CONCLUSIONS: The SFR demonstrates a high PPV for accurately classifying burst fractures, regardless of physician experience, treatment and hospital type. However, the reliability of B-type injuries and overall classification in the SFR was found to be low. Future studies on burst fractures using SFR data where classification is important should include a review of medical images to verify the diagnosis.

Validity of the short musculoskeletal function assessment questionnaire in patients with a spine fracture.

PURPOSE: The aim of this study was to validate the use of the Short Musculoskeletal Function Assessment (SMFA) questionnaire in patients with a spine fracture. METHODS: Cross-sectional cohort of individuals that had sustained a spine fracture (C1-L5) one year earlier. Patients were asked to fill out SMFA, Oswestry Disability Index (ODI), EQ-5D-3L and EQ-VAS. Spearman's rank correlation coefficient (rho) was used to assess convergent validity for each patient-reported outcome measure (PROM). Bland-Altman plots were used to assess PROM agreement. RESULTS: 82 patients completed all questionnaires. The correlations between SMFA Dysfunction and Bother indices and ODI were 0.89 and 0.86, with EQ-5D-3L index 0.89 and 0.80, and with EQ-VAS 0.80 and 0.73, respectively. The correlation for separate categories of the SMFA dysfunction index (daily activities, emotional status, arm and hand function, mobility) ranged between 0.71-0.87 for ODI, 0.72-0.84 for EQ-5D-3L index, and 0.67-0.77 for EQ-VAS. A selection of the ten items of SMFA that had the highest correlations with ODI resulted in a correlation of 0.91. The agreements between SMFA indices and ODI in Bland-Altman plots were good with small differential biases and minimal proportional biases, but worse for SMFA and EQ-5D-3L index and EQ-VAS. CONCLUSION: The SMFA indices are highly correlated with ODI in patients with a spine fracture. The Dysfunction index and Bother index, or selected SMFA items, may be used to assess outcome in patients with spine fractures as an alternative to ODI.

Study protocol: The SunBurst trial-a register-based, randomized controlled trial on thoracolumbar burst fractures.

BACKGROUND AND PURPOSE: The treatment for patients with thoracolumbar burst fractures without neurological deficit or complete rupture of the posterior ligament complex (PLC) is controversial and includes both surgical and non-surgical options. Current evidence on which treatment is optimal remains inconclusive. In this study we compare surgical with non-surgical treatment. METHODS: The study is a nationwide, multicenter, register-based randomized controlled trial (R-RCT). Patients with a thoracolumbar burst fracture will be identified by the Swedish Fracture Register. The admitting physician will be notified during the registration process and the patient will be screened for eligibility. Patients, 18 to 66 years old without neurologic deficit to more than a single nerve root and without complete rupture of the PLC, are eligible for the study. 202 patients will be randomized in a 1:1 relation to either surgical or non-surgical treatment. Patient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI) and radiological data, will be collected at the time of injury, after 3-4 months, and after 1 year. Additional data from national health registries will be collected after 1 year. OUTCOME: The primary outcome is the ODI 1 year after injury. Secondary outcomes include additional PROMs, adverse events, drug consumption, sick leave, healthcare consumption, and imaging data. INTERPRETATION: The primary outcome is the ODI 1 year after injury. Secondary outcomes include additional PROMs, adverse events, drug consumption, sick leave, healthcare consumption, and imaging data. Estimated duration - The study started on September 1, 2021 and will continue for approximately 4 years. Trial registration - The trial is registered at www.clinicaltrials.com, NCT05003180.

A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis.

BACKGROUND: The efficacy of fusion surgery in addition to decompression surgery in patients who have lumbar spinal stenosis, with or without degenerative spondylolisthesis, has not been substantiated in controlled trials. METHODS: We randomly assigned 247 patients between 50 and 80 years of age who had lumbar spinal stenosis at one or two adjacent vertebral levels to undergo either decompression surgery plus fusion surgery (fusion group) or decompression surgery alone (decompression-alone group). Randomization was stratified according to the presence of preoperative degenerative spondylolisthesis (in 135 patients) or its absence. Outcomes were assessed with the use of patient-reported outcome measures, a 6-minute walk test, and a health economic evaluation. The primary outcome was the score on the Oswestry Disability Index (ODI; which ranges from 0 to 100, with higher scores indicating more severe disability) 2 years after surgery. The primary analysis, which was a per-protocol analysis, did not include the 14 patients who did not receive the assigned treatment and the 5 who were lost to follow-up. RESULTS: There was no significant difference between the groups in the mean score on the ODI at 2 years (27 in the fusion group and 24 in the decompression-alone group, P=0.24) or in the results of the 6-minute walk test (397 m in the fusion group and 405 m in the decompression-alone group, P=0.72). Results were similar between patients with and those without spondylolisthesis. Among the patients who had 5 years of follow-up and were eligible for inclusion in the 5-year analysis, there were no significant differences between the groups in clinical outcomes at 5 years. The mean length of hospitalization was 7.4 days in the fusion group and 4.1 days in the decompression-alone group (P<0.001). Operating time was longer, the amount of bleeding was greater, and surgical costs were higher in the fusion group than in the decompression-alone group. During a mean follow-up of 6.5 years, additional lumbar spine surgery was performed in 22% of the patients in the fusion group and in 21% of those in the decompression-alone group. CONCLUSIONS: Among patients with lumbar spinal stenosis, with or without degenerative spondylolisthesis, decompression surgery plus fusion surgery did not result in better clinical outcomes at 2 years and 5 years than did decompression surgery alone. (Funded by an Uppsala institutional Avtal om Läkarutbildning och Forskning [Agreement concerning Cooperation on Medical Education and Research] and others; Swedish Spinal Stenosis Study ClinicalTrials.gov number, NCT01994512.).

Decompression alone or decompression with fusion for lumbar spinal stenosis: five-year clinical results from a randomized clinical trial.

Aims: We compared decompression alone to decompression with fusion surgery for lumbar spinal stenosis, with or without degenerative spondylolisthesis (DS). The aim was to evaluate if five-year outcomes differed between the groups. The two-year results from the same trial revealed no differences. Methods: The Swedish Spinal Stenosis Study was a multicentre randomized controlled trial with recruitment from September 2006 to February 2012. A total of 247 patients with one- or two-level central lumbar spinal stenosis, stratified by the presence of DS, were randomized to decompression alone or decompression with fusion. The five-year Oswestry Disability Index (ODI) was the primary outcome. Secondary outcomes were the EuroQol five-dimension questionnaire (EQ-5D), visual analogue scales for back and leg pain, and patient-reported satisfaction, decreased pain, and increased walking distance. The reoperation rate was recorded. Results: Five-year follow-up was completed by 213 (95%) of the eligible patients (mean age 67 years; 155 female (67%)). After five years, ODI was similar irrespective of treatment, with a mean of 25 (SD 18) for decompression alone and 28 (SD 22) for decompression with fusion (p = 0.226). Mean EQ-5D was higher for decompression alone than for fusion (0.69 (SD 0.28) vs 0.59 (SD 0.34); p = 0.027). In the no-DS subset, fewer patients reported decreased leg pain after fusion (58%) than with decompression alone (80%) (relative risk (RR) 0.71 (95% confidence interval (CI) 0.53 to 0.97). The frequency of subsequent spinal surgery was 24% for decompression with fusion and 22% for decompression alone (RR 1.1 (95% CI 0.69 to 1.8)). Conclusion: Adding fusion to decompression in spinal stenosis surgery, with or without spondylolisthesis, does not improve the five-year ODI, which is consistent with our two-year report. Three secondary outcomes that did not differ at two years favoured decompression alone at five years. Our results support decompression alone as the preferred method for operating on spinal stenosis.

Novel Calcium Phosphate Promotes Interbody Bony Fusion in a Porcine Anterior Cervical Discectomy and Fusion Model.

STUDY DESIGN: Experimental porcine anterior cervical discectomy and fusion (ACDF) model: a proof-of-concept study. OBJECTIVE: The effect of monetite synthetic bone graft (SBG) containing calcium pyrophosphate and ß-tricalcium phosphate on cervical spinal fusion in a noninstrumented two-level large animal model. SUMMARY OF BACKGROUND DATA: ACDF is the gold standard surgical technique for the treatment of degenerative cervical spinal diseases. However, pseudarthrosis associated with increased patient morbidity occurs in ∼2.6% of the surgeries. SBG may enhance bony fusion and subsequently decrease the risk of pseudarthrosis. Recent studies on monetite-based SBGs for use in large cranial defects in humans have shown promising bone healing results, necessitating further investigation of their use in cervical spinal fusion. MATERIALS AND METHODS: Four adult female Danish Göttingen minipigs received partial cervical anterior discectomy and intervertebral defects at an upper and lower level. One defect was filled with SBG, and the other was left empty. Bony fusion was evaluated using computed tomography (CT) at three-month intervals for 12 months. Fifteen months postsurgery, the animals were euthanized for further ex vivo qualitative histopathologic and micro-CT evaluations. Fusion rates were compared using the Fisher exact test at each time point. RESULTS: Increased interbody bony fusion rates were observed at SBG levels (4/4) compared with control levels (0/4) evaluated by CT at 6 and 9 months postsurgery ( P =0.029). Fusion was observed at all SBG levels 12 months postsurgery and at only one control level. Histopathologic evaluation confirmed high-quality interbody bony fusion at all SBG levels and fusion by spondylosis at one control level. CONCLUSION: This proof-of-concept study provides preliminary evidence of a novel, calcium pyrophosphate-containing, and ß-tricalcium phosphate-containing monetite SBG that promotes bony fusion compared with a negative control in a clinically relevant porcine model of ACDF.

No Benefit with Preservation of Midline Structures in Decompression for Lumbar Spinal Stenosis: Results From the National Swedish Spine Registry 2-Year Post-Op.

STUDY DESIGN: Observational cohort study. OBJECTIVE: The aim of this study was to investigate whether preservation of the midline structures is associated with a better clinical outcome compared to classic central decompression for lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: The classic surgical procedure for LSS is a central, facet joint sparing decompressive laminectomy (LE). Alternative approaches have been developed to preserve the midline structures. The effect of the alternative techniques compared to LE remains unclear. METHODS: All patients >50 years of age who underwent decompression surgery for LSS without concomitant fusion in the National Swedish Spine Registry (Swespine) from December 31, 2015 until October 6, 2017 were included in this study based on surgeon-reported data and patient questionnaires before and 2 years postoperatively. Propensity score matching was used to compare decompression with preservation of midline structures with patients who underwent LE. The primary outcome was the Oswestry Disability Index (ODI) and secondary outcomes were the Numeric Rating Scale (NRS) for leg and back pain, EuroQol-5 Dimensions (EQ-5D), Global Assessment (GA), patient satisfaction and rate of subsequent surgery. RESULTS: Some 3339 patients completed a 2-year follow-up. Of these, 2974 (89%) had decompression with LE and 365 underwent midline preserving surgery. Baseline scores were comparable between the groups. Mean ODI improvement at follow-up was 16.6 (SD = 20.0) in the LE group and 16.9 (SD = 20.2) in the midline preserving surgery group. In the propensity score-matched analysis the difference in improved ODI was 0.53 (95% confidence interval, CI -1.71 to 2.76; P = 0.64). The proportion of patients who showed a decreased ODI score of at least our defined minimal clinically important difference (=8) was 68.3% after LE and 67.0% after preserving the midline structures (P = 0.73). No significant differences were found in the improvement of NRS for leg and back pain, EQ-5D, GA or patient satisfaction. The rate of subsequent surgery was 5.5% after LE and 4.9% after midline preserving surgery without a significant difference in the propensity score-matched analysis (hazard ratio, HR 0.87; 95% CI 0.49-1.54; P = 0.64). CONCLUSION: In this study on decompression techniques for LSS, there was no benefit in preserving the midline structures compared to LE 2 years after decompression. The conclusion is that the surgeon is free to choose the surgical method that is thought most suitable for the patient and the condition with which the patient presents.Level of Evidence: 3.

Low-Modulus PMMA Has the Potential to Reduce Stresses on Endplates after Cement Discoplasty.

Cement discoplasty has been developed to treat patients with advanced intervertebral disc degeneration. In discoplasty, poly(methylmethacrylate) (PMMA) bone cement is injected into the disc, leading to reduced pain and certain spinal alignment correction. Standard PMMA-cements have much higher elastic modulus than the surrounding vertebral bone, which may lead to a propensity for adjacent fractures. A PMMA-cement with lower modulus might be biomechanically beneficial. In this study, PMMA-cements with lower modulus were obtained using previously established methods. A commercial PMMA-cement (V-steady®, G21 srl) was used as control, and as base cement. The low-modulus PMMA-cements were modified by 12 vol% (LA12), 16 vol% (LA16) and 20 vol% (LA20) linoleic acid (LA). After storage in 37 °C PBS from 24 h up to 8 weeks, specimens were tested in compression to obtain the material properties. A lower E-modulus was obtained with increasing amount of LA. However, with storage time, the E-modulus increased. Standard and low-modulus PMMA discoplasty were compared in a previously developed and validated computational lumbar spine model. All discoplasty models showed the same trend, namely a substantial reduction in range of motion (ROM), compared to the healthy model. The V-steady model had the largest ROM-reduction (77%), and the LA20 model had the smallest (45%). The average stress at the endplate was higher for all discoplasty models than for the healthy model, but the stresses were reduced for cements with higher amounts of LA. The study indicates that low-modulus PMMA is promising for discoplasty from a mechanical viewpoint. However, validation experiments are needed, and the clinical setting needs to be further considered.

Lumbar Spinal Stenosis with Degenerative Spondylolisthesis Treated with Decompression Alone. A Cohort of 346 Patients at a Large Spine Unit. Clinical Outcome, Complications and Subsequent Surgery.

STUDY DESIGN: Cohort study. OBJECTIVE: To study the clinical outcome, complications and subsequent surgery rate of DA for lumbar spinal stenosis (LSS) with DS. SUMMARY OF BACKGROUND DATA: There is still no consensus regarding the treatment approach for LSS with DS. METHODS: We performed a retrospectively designed cohort study on prospectively collected data from a single high productive spine surgical center. Results from the Swedish Spine Registry and a local register for complications were used for the analyses. Patients with LSS and DS (>3 mm) who underwent DA during January 2012 to August 2017 were included. Patient reported outcome measures at baseline and 2 years after surgery were analyzed. Complications within 30 days of surgery and all subsequent surgery in the lumbar spine were registered. RESULTS: We identified and included 346 patients with completed 2-year follow-up registration. At 2-year follow-up there was a significant improvement in all outcome measures. The global assessment success rate for back and leg pain was 68.3% and 67.6% respectively. Forty-one patients had at least 1 intra- or postoperative complication (11.9%). Nine patients (2.6%), underwent subsequent surgery within 2 years of the primary surgery whereof 2 underwent fusion. During the whole period of data collection, that is, as of June 2020, 28 patients had undergone subsequent surgery (8.1%) whereas 8 of them had had 2 surgeries. Fifteen patients underwent fusion. CONCLUSION: DA provides good clinical outcome at 2-year follow-up in patients with LSS and DS with low rate of intra- and postoperative complications and subsequent surgery. Our data supports the evidence that DA is effective and safe for LSS with DS.Level of Evidence: 3.

Decompression alone or decompression with fusion for lumbar spinal stenosis: a randomized clinical trial with two-year MRI follow-up.

AIMS: The aims of this study were first, to determine if adding fusion to a decompression of the lumbar spine for spinal stenosis decreases the rate of radiological restenosis and/or proximal adjacent level stenosis two years after surgery, and second, to evaluate the change in vertebral slip two years after surgery with and without fusion. METHODS: The Swedish Spinal Stenosis Study (SSSS) was conducted between 2006 and 2012 at five public and two private hospitals. Six centres participated in this two-year MRI follow-up. We randomized 222 patients with central lumbar spinal stenosis at one or two adjacent levels into two groups, decompression alone and decompression with fusion. The presence or absence of a preoperative spondylolisthesis was noted. A new stenosis on two-year MRI was used as the primary outcome, defined as a dural sac cross-sectional area ≤ 75 mm2 at the operated level (restenosis) and/or at the level above (proximal adjacent level stenosis). RESULTS: A total of 211 patients underwent surgery at a mean age of 66 years (69% female): 103 were treated by decompression with fusion and 108 by decompression alone. A two-year MRI was available for 176 (90%) of the eligible patients. A new stenosis at the operated and/or adjacent level occurred more frequently after decompression and fusion than after decompression alone (47% vs 29%; p = 0.020). The difference remained in the subgroup with a preoperative spondylolisthesis, (48% vs 24%; p = 0.020), but did not reach significance for those without (45% vs 35%; p = 0.488). Proximal adjacent level stenosis was more common after fusion than after decompression alone (44% vs 17%; p < 0.001). Restenosis at the operated level was less frequent after fusion than decompression alone (4% vs 14%; p = 0.036). Vertebral slip increased by 1.1 mm after decompression alone, regardless of whether a preoperative spondylolisthesis was present or not. CONCLUSION: Adding fusion to a decompression increased the rate of new stenosis on two-year MRI, even when a spondylolisthesis was present preoperatively. This supports decompression alone as the preferred method of surgery for spinal stenosis, whether or not a degenerative spondylolisthesis is present preoperatively.Cite this article: Bone Joint J 2022;104-B(12):1343-1351.

An ex-vivo model for the biomechanical assessment of cement discoplasty.

Percutaneous Cement Discoplasty (PCD) is a surgical technique developed to relieve pain in patients with advanced degenerative disc disease characterized by a vacuum phenomenon. It has been hypothesized that injecting bone cement into the disc improves the overall stability of the spinal segment. However, there is limited knowledge on the biomechanics of the spine postoperatively and a lack of models to assess the effect of PCD ex-vivo. This study aimed to develop a biomechanical model to study PCD in a repeatable and clinically relevant manner. Eleven ovine functional spinal units were dissected and tested under compression in three conditions: healthy, injured and treated. Injury was induced by a papain buffer and the treatment was conducted using PMMA cement. Each sample was scanned with micro-computed tomography (CT) and segmented for the three conditions. Similar cement volumes (in %) were injected in the ovine samples compared to volumes measured on clinical PCD CT images. Anterior and posterior disc heights decreased on average by 22.5% and 23.9% after injury. After treatment, the anterior and posterior disc height was restored on average to 98.5% and 83.6%, respectively, of their original healthy height. Compression testing showed a similar stiffness behavior between samples in the same group. A decrease of 51.5% in segment stiffness was found after injury, as expected. The following PCD treatment was found to result in a restoration of stiffness-showing only a difference of 5% in comparison to the uninjured state. The developed ex-vivo model gave an adequate representation of the clinical vacuum phenomena in terms of volume, and a repeatable mechanical response between samples. Discoplasty treatment was found to give a restoration in stiffness after injury. The data presented confirm the effectiveness of the PCD procedure in terms of restoration of axial stiffness in the spinal segment. The model can be used in the future to test more complex loading scenarios, novel materials, and different surgical techniques.

[Lumbar disc prosthesis, a high risk treatment for low back pain.] / Diskprotes ­ en riskabel behandling av ländryggssmärta.

When surgery is needed for chronic low back pain, replacement of the degenerated and potential pain generating disc with a prosthesis often gives good short-term pain relief. However, there is no evidence of the clinical superiority of prosthesis compared with other treatments. Disc prosthesis is associated with considerable risks of late severe complications, especially in revision surgery. The method has been suggested as a treatment for young active patients, which is highly questionable considering  the risk of late severe adverse events and complex revision surgery. Globally the method is declining and in many health care financing models it is not an approved treatment. In Sweden, the use of disc prosthesis is increasing.

Study protocol for a randomised controlled trial with clinical, neurophysiological, laboratory and radiological outcome for surgical versus non-surgical treatment for lumbar spinal stenosis: the Uppsala Spinal Stenosis Trial (UppSten).

INTRODUCTION: Symptomatic lumbar spinal stenosis is the most common indication for spinal surgery. However, more than one-third of the patients undergoing surgery for lumbar stenosis report dissatisfaction with the results. On the other hand, conservative treatment has shown positive results in some cases. This trial will compare the outcomes of surgical versus non-surgical treatment for lumbar stenosis. The study includes a multidimensional follow-up, aiming to study the association between outcome and other studied parameters, mainly electromyography and nerve conduction. Moreover, it may contribute to a better understanding of the pathophysiology of lumbar stenosis and to the development of future pharmacological treatments. METHODS AND ANALYSIS: UppSten is a single-centre randomised controlled trial in which 150 patients with symptomatic lumbar spinal stenosis will be randomised into one of two treatment arms. The patients in the surgical arm will undergo laminectomy; the patients in the non-surgical arm will be given a structured physical training programme. The primary outcome of the study will be the Oswestry Disability Index. Secondary outcomes will include motor amplitude and degree of denervation activity obtained by means of nerve conduction studies and electromyography. Patient-reported outcome measures will be also used as secondary outcomes. Blood sample analysis and the investigation of potential inflammation markers are the additional secondary outcome parameters. Laboratory evaluation will include blood sample collection before the treatment initiation and after 6 months. Flavum ligament biopsies will be performed in the surgical group. Finally, tertiary outcomes will include neurophysiological measures, the objective walking ability and radiological evaluation. ETHICS AND DISSEMINATION: The study is approved by the Local Ethics Committee (Dnr 2017-506), the Hospital's Clinical Trials Committee (2018-0001) and the National Biobank Council and Uppsala Biobank (BbA-827-2018-025). The results will be presented in peer-reviewed journals and at international conferences. TRIAL REGISTRATION NUMBER: NCT03495661.

Safety of a novel modular cage for transforaminal lumbar interbody fusion - clinical cohort study in 20 patients with degenerative disc disease.

INTRODUCTION: Transforaminal lumbar interbody fusion (TLIF) is used to reconstruct disc height and reduce degenerative deformity in spinal fusion. Patients with osteoporosis are at high risk of TLIF cage subsidence; possibly due to the relatively small footprint compared to anterior interbody devices. Recently, modular TLIF cage with an integral rail and slot system was developed to reduce cage subsidence and allow early rehabilitation. OBJECTIVE: To study the safety of a modular TLIF device in patients with degenerative disc disorders (DDD) with regard to surgical complications, non-union, and subsidence. METHODS: Patients with DDD treated with a modular TLIF cage (Polyetheretherketone (PEEK), VTI interfuse S) were analysed retrospectively with one-year follow-up. Lumbar sagittal parameters were collected preoperatively, postoperatively and at one year follow-up. Cage subsidence, fusion rate, screw loosening and proportion of endplate coverage were assessed in computed tomography scan. RESULTS: 20 patients (age 66 ± 10 years, 65% female, BMI 28 ± 5 kg/m2) with a total of 37 fusion levels were included. 15 patients had degenerative spondylosis and 5 patients had degenerative scoliosis. The cages covered >60% of the vertebral body diameters. Lumbar lordosis angle and segmental disc angle increased from 45.2 ± 14.5 and 7.3 ± 3.6 to 52.7 ± 9.1 and 10.5 ± 3.5 (p = 0.029 and 0.0002) postoperatively for each parameter respectively without loss of correction at one year follow up. One case of deep postoperative infection occurred (5%). No cage subsidence occurred. No non-union or screw loosening occurred. CONCLUSIONS: The modular TLIF cage was safe with regard to subsidence and union-rate. It restored and maintained lumbar lordosis angle, segmental disc angle and disc height, which can be attributed to the large footprint of this modular cage.

Motion Analysis in Lumbar Spinal Stenosis With Degenerative Spondylolisthesis: A Feasibility Study of the 3DCT Technique Comparing Laminectomy Versus Bilateral Laminotomy.

STUDY DESIGN: This was a randomized radiologic biomechanical pilot study in vivo. OBJECTIVE: The objectives of this study was to evaluate if 3-dimensional computed tomography is a feasible tool in motion analyses of the lumbar spine and to study if preservation of segmental midline structures offers less postoperative instability compared with central decompression in patients with lumbar spinal stenosis with degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: The role of segmental instability after decompression is controversial. Validated techniques for biomechanical evaluation of segmental motion in human live subjects are lacking. METHODS: In total, 23 patients (mean age, 68 y) with typical symptoms and magnetic resonance imaging findings of spinal stenosis with degenerative spondylolisthesis (>3 mm) in 1 or 2 adjacent lumbar levels from L3 to L5 were included. They were randomized to either laminectomy (LE) or bilateral laminotomy (LT) (preservation of the midline structures). Documentation of segmental motion was made preoperatively and 6 months postoperatively with CT in provoked flexion and extension. Analyses of movements were performed with validated software. The accuracy for this method is 0.6 mm in translation and 1 degree in rotation. Patient-reported outcome measures were collected from the Swespine register preoperatively and 2-year postoperatively. RESULTS: The mean preoperative values for 3D rotation and translation were 6.2 degrees and 1.8 mm. The mean increase in 3D rotation 6 months after surgery was 0.25 degrees after LT and 0.7 degrees after LE (P=0.79) while the mean increase in 3D translation was 0.15 mm after LT and 1.1 mm after LE (P=0.42). Both surgeries demonstrated significant improvement in patient-reported outcome measures 2 years postoperatively. CONCLUSIONS: The 3D computed tomography technique proved to be a feasible tool in the evaluation of segmental motion in this group of older patients. There was negligible increase in segmental motion after decompressive surgery. LE with removal of the midline structures did not create a greater instability compared with when these structures were preserved.

Smokers show less improvement than nonsmokers two years after surgery for lumbar spinal stenosis: a study of 4555 patients from the Swedish spine register.

STUDY DESIGN: A cohort study based on the Swedish Spine Register. OBJECTIVE: To determine the relation between smoking status and disability after surgical treatment for lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Smoking and nicotine have been shown to inhibit lumbar spinal fusion and promote disc degeneration. No association, however, has previously been found between smoking and outcome after surgery for lumbar spinal stenosis. A large prospective study is therefore needed. METHODS: All patients with a completed 2-year follow-up in the Swedish Spine Register operated for central lumbar stenosis before October 1, 2006 were included. Logistic regression was used to assess the association between smoking status and outcomes. RESULTS: Of 4555 patients enrolled, 758 (17%) were current smokers at the time of surgery. Smokers had an inferior health-related Quality of Life at baseline. Nevertheless, adjusted for differences in baseline characteristics, the odds ratio (OR) for a smoker to end up dissatisfied at the 2-year follow-up after surgery was 1.79 [95% confidence interval (CI) 1.51-2.12]. Smokers had more regular use of analgesics (OR 1.86; 95% CI 1.55-2.23). Walking ability was less likely to be significantly improved in smokers with an OR of 0.65 (95% CI 0.51-0.82). Smokers had inferior Quality of Life also after taking differences before surgery into account, either when measured with the Oswestry Disability Index (ODI; P < 0.001), EuroQol (P < 0.001) or Short Form (36) Health Survey (SF-36) BP and SF-36 PF (P < 0.001). The differences in results between smokers and nonsmokers were evident, irrespective of whether the decompression was done with or without spinal fusion. CONCLUSION: Smoking is an important predictor for 2-year results after surgery for lumbar spinal stenosis. Smokers had less improvement after surgery than nonsmokers.

Kyphoplasty in osteoporotic vertebral compression fractures--guidelines and technical considerations.

Osteoporotic vertebral compression fractures are a menace to the elderly generation causing diminished quality of life due to pain and deformity. At first, conservative treatment still is the method of choice. In case of resulting deformity, sintering and persistent pain vertebral cement augmentation techniques today are widely used. Open correction of resulting deformity by different types of osteotomies addresses sagittal balance, but has comparably high morbidity. Besides conventional vertebral cement augmentation techniques balloon kyphoplasty has become a popular tool to address painful thoracic and lumbar compression fractures. It showed improved pain reduction and lower complication rates compared to standard vertebroplasty. Interestingly the results of two placebo-controlled vertebroplasty studies question the value of cement augmentation, if compared to a sham operation. Even though there exists now favourable data for kyphoplasty from one randomised controlled trial, the absence of a sham group leaves the placebo effect unaddressed. Technically kyphoplasty can be performed with a transpedicular or extrapedicular access. Polymethyl methacrylate (PMMA)-cement should be favoured, since calcium phosphate cement showed inferior biomechanical properties and less effect on pain reduction especially in less stable burst fractures. Common complications of kyphoplasty are cement leakage and adjacent segment fractures. Rare complications are toxic PMMA-monomer reactions, cement embolisation, and infection.