The study group.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(18)30489-6.pdf

Prevention and treatment of low back pain: evidence, challenges, and promising directions.

A review on calcium phosphate coatings produced using a sputtering process--an alternative to plasma spraying.

BackgroundThe 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. MethodsWe 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 1...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa1513721

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

BackgroundThe comparative effectiveness of performing instrumented (rigid pedicle screws affixed to titanium alloy rods) lumbar spinal fusion in addition to decompressive laminectomy in patients with symptomatic lumbar grade I degenerative spondylolisthesis with spinal stenosis is unknown. MethodsIn this randomized, controlled trial, we assigned patients, 50 to 80 years of age, who had stable degenerative spondylolisthesis (degree of spondylolisthesis, 3 to 14 mm) and symptomatic lumbar spinal stenosis to undergo either decompressive laminectomy alone (decompression-alone group) or laminectomy with posterolateral instrumented fusion (fusion group). The primary outcome measure was the change in the physical-component summary score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36; range, 0 to 100, with higher scores indicating better quality of life) 2 years after surgery. The secondary outcome measure was the score on the Oswestry Disability Index (range, 0 to 100, with higher scores i...

https://www.nejm.org/doi/pdf/10.1056/NEJMoa1508788

Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis

Introduction
Swespine, the Swedish National Spine Register, has existed for 20 years and is in general use within the country since over 10 years regarding degenerative lumbar spine disorders Today there are protocols for registering all disorders of the entire spinal column

/pdf/swespine-the-swedish-spine-register-the-2012-report-1yvux4rn94.pdf

Swespine: the Swedish spine register: The 2012 report

Study design A cohort study based on the Swedish Spine Register. Objective To determine the association between body mass index (BMI) and outcome of lumbar spine surgery for spinal stenosis. Summary of background data Several small studies have sought to evaluate the importance of obesity in relation to results after surgery for lumbar spinal stenosis (LSS), but the findings are inconsistent and relatively weak. Methods All patients who underwent surgery for LSS from January 1, 2006, to June 30, 2008, with a completed 2-year follow-up in the Swedish Spine Register were included. Logistic regression was used to assess the association between BMI and different outcomes. Results Of the 2633 patients enrolled, 819 (31%) had normal weight, 1208 (46%) were overweight, and 606 (23%) were obese. On average, all 3 BMI groups achieved significant improvements after surgery. A higher BMI, however, was associated with greater odds of dissatisfaction after surgery and inferior results at the 2-year follow-up. After adjusting for differences in baseline characteristics, the obese group demonstrated inferior function and quality of life as measured by the Oswestry Disability Index (ODI) and the EuroQol Group Index (EQ-5D), respectively. At the 2-year follow-up, obese patients had a mean ODI of 33 (95% confidence interval [CI], 31-34) and mean EQ-5D of 0.56 (95% CI, 0.54-0.59) compared with a mean ODI of 25 (95% CI, 24-26) and mean EQ-5D of 0.64 (95% CI, 0.62-0.66) in the normal weight group. When compared with the normal weight patients, the adjusted odds ratio for dissatisfaction was 1.73 in the obese group (95% CI, 1.36-2.19). Differences between the normal weight and overweight groups were modest and therefore could not be considered clinically relevant. Conclusion Obese patients achieved significant pain reduction, better walking ability, and improved quality of life after surgical treatment of LSS. Nevertheless, obesity was associated with a higher degree of dissatisfaction and poorer outcomes after surgery for LSS.

Obesity is associated with inferior results after surgery for lumbar spinal stenosis: a study of 2633 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.

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

We examined the radiographs from a prospective clinical study of fixation by pedicle screws and those from an experimental study in a sheep model. In the clinical study, instruments were removed from 21 patients after implantation for 11 to 16 months and the extraction torques of the screws were recorded. A structured protocol was used for the radiological examinations. In the experimental study, loaded pedicle screw instrumentations were implanted in the sheep for six or 12 weeks. After radiological examination the pull-out resistance and the histological characteristics were studied. In the clinical study, all screws with radiolucent zones had a significantly reduced mean extraction torque compared with screws without radiolucent zones (16 ± 10 Ncm v 403 ± 220 Ncm; p < 0.0001). In the experimental study the mean maximum pull-out resistance for the screws with radiolucent zones was significantly lower than for those with no radiolucency (243 ± 156 N v 2214 ± 578 N; p = 0.0006) and the mean bone-to-screw contact was reduced for screws with zones compared with those without zones (8 ± 9% v 55 ± 29%; p = 0.0002). Our findings showed that all screws with radiolucent zones had low extraction torques or low pull-out resistance. A radiolucent zone is a good indicator of loosening of a pedicle screw.

Bengt Sandén

Papers

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

Swespine: the Swedish spine register: The 2012 report

Obesity is associated with inferior results after surgery for lumbar spinal stenosis: a study of 2633 patients from the Swedish spine register.

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

The significance of radiolucent zones surrounding pedicle screws. Definition of screw loosening in spinal instrumentation.