Does daily tobacco smoking affect outcomes after microdecompression for degenerative central lumbar spinal stenosis? - A multicenter observational registry-based study

Influence of smoking on patient-reported outcome measures (PROMs) in patients undergoing surgery for adult spinal deformity: a propensity score-matched analysis

PURPOSE

The purpose of this study was to determine the isolated influence of smoking in patient-reported outcome measures (PROMs) for adult spinal deformity (ASD) surgery excluding known tobacco-related complications.

METHODS

Retrospective analysis of a prospective multicenter ASD database. Patients operated on ASD with 2 year post-operative follow-up were included. Former smokers (non-active smokers) and patients developing mechanical or infectious complications were excluded. Changes of PROMs over time were analyzed using mixed models for repeated measures (MMRM). Propensity score matching (PSM) (1:1 ratio, caliper 0.10) was performed without replacement using optimum algorithm, tolerance ≤ 0.001, and estimated with 95% confidence interval (CI). PROMS in both groups were compared by paired t test or Wilcoxon signed-rank test.

RESULTS

692 out of 1246 surgical patients met our inclusion criteria. 153 smokers were matched with 153 non-smokers according to age, BMI, number of fused levels, and global tilt. After PSM both groups were homogeneous regarding baseline parameters, surgical data, and complications (mechanical complications and infection excluded). Smokers had worse baseline results for SRS-total, SRS-pain COMI-back, and ODI; smokers also showed worse 2-year outcomes for SRS-total, SRS-function, SRS-pain, SRS-self-image, and ODI. However, no differences between the two groups were found in the improvement from baseline to 2-year follow-up or in the timing of this improvement (MMRM). The proportion of patients reaching the minimal clinically important difference (MCID) after surgery was similar in the two groups, but the proportion of patients reaching patient acceptable symptom state (PASS) was significantly lower in smokers for SRS-Subtotal, SRS-function, and SRS-image.

CONCLUSION

Even in the absence of smoking-related complications, smokers had worse PROMs at baseline and 2 years after surgery with less patients achieving PASS, but similar degrees on improvement compared to non-smokers. The proportion achieving MCID was also similar between the two cohorts.

Development and temporal validation of clinical prediction models for 1-year disability and pain after lumbar decompressive surgery. The Norwich Lumbar Surgery Predictor (development version)

PURPOSE

To identify clinical predictors and build prediction models for 1-year patient-reported outcomes measures (PROMs) after lumbar decompressive surgery for disc herniation or spinal stenosis.

METHODS

The study included 1835 cases, with or without additional single-level fusion, from a single centre from 2008 through 2020. General linear models imputed with 37 clinical variables identified 18 significant 1-year PROM predictors for retention in development models. Interaction of surgical indication with each predictor was tested. Temporal validation was conducted at the same centre on cases through 2021. R2 was used to measure goodness-of-fit, and area under curve (AUC) used to measure classification to a satisfactory symptom state (Oswestry Disability Index (ODI) ≤ 22; back or leg pain ≤ 30 out of 100).

RESULTS

A total 1228 (67%) had complete data for inclusion in model development. Predictors of ODI were baseline PROMs (ODI, back pain, leg pain), work status, condition duration, previous lumbar operation, multiple-joint osteoarthritis, female, diabetes, current smoker, rheumatic disorder, lower limb arthroplasty, mobility aided, provider status, facet cyst, scoliosis, and age, with BMI significantly associated with stenosis. Temporal validation (n = 188) found the ODI model R2 was 0.29 (95% confidence intervals (CI) 0.18-0.40) and AUC was 0.74 (95% CI 0.67-0.81). Back and leg pain models had lower R2 (0.12-0.14) and AUC (0.68-0.69) values.

CONCLUSION

Important PROM predictors are baseline PROMs, specific co-morbidities, work status, condition duration, previous lumbar operation, female, and smoking status. The ODI model predicted the likelihood of achieving a satisfactory state of both disability and pain.

Does Tobacco Smoking Affect the Postoperative Outcome of MIS Lumbar Decompression Surgery?

BACKGROUND

Tobacco smoking is a major cause of morbidity and mortality worldwide. Several authors reported a significant negative impact of smoking on the outcome of spinal surgeries. However, comparative studies on the effect of smoking on the outcome of minimally invasive (MIS) spinal decompression are rare with conflicting results. In this study, we aimed to evaluate clinical outcomes and postoperative complications following MIS decompression in current and former smoking patients compared to those of non-smoking patients.

METHODS

We used our prospectively collected database to retrospectively analyse the records of 188 consecutive patients treated with MIS lumbar decompression at our institution between November 2013 and July 2017. Patients were divided into groups of smokers (S), previous smokers (PS) and non-smokers (N). The S group and the PS group comprised 31 and 40 patients, respectively. The N group included 117 patients. The outcome measures included perioperative complications, revision surgery and length of stay. Patient-reported outcome measures included a visual analogue scale (VAS) for back pain and leg pain, as well as the Oswestry disability index (ODI) for evaluating functional outcomes.

RESULTS

Demographic variables, comorbidity and other preoperative variables were comparable between the three groups. A comparison of perioperative complications and revision surgery rates showed no significant difference between the groups. All groups showed significant improvement in their ODI and VAS scores at 12 and 24 months following surgery. As shown by a multivariate analysis, current smokers had lower chances of improvement, exceeding the minimal clinical important difference (MCID) in ODI and VAS for leg pain at 12 months but not 24 months postoperatively.

CONCLUSIONS

Our findings show that except for a possible delay in improvement in leg pain and disability, tobacco smoking has no substantial adverse impact on complications and revision rates following MIS spinal decompressions.

The Potential Negative Effects of Smoking on Cervical and Lumbar Surgery Beyond Pseudarthrosis: A Michigan Spine Surgery Improvement Collaborative Study

OBJECTIVE

To review the Michigan Spine Surgery Improvement Collaborative registry to investigate the long-term associations between current smoking status and outcomes after elective cervical and lumbar spine surgery.

METHODS

Using the Michigan Spine Surgery Improvement Collaborative, we captured all cases from January 1, 2017, to November 21, 2020, with outcomes data available; 19,251 lumbar cases and 7936 cervical cases were included. Multivariate regression analyses were performed to assess the relationship of smoking with the clinical outcomes.

RESULTS

Current smoking status was associated with lower urinary retention and satisfaction for patients after lumbar surgery and was associated with less likelihood of achieving minimal clinically important difference in primary outcome measures including Patient-Reported Outcomes Measurement Information System, back pain, leg pain, and EuroQol-5D at 90 days and 1 year after surgery. Current smokers were also less likely to return to work at 90 days and 1 year after surgery. Among patients who underwent cervical surgery, current smokers were less likely to have urinary retention and dysphagia postoperatively. They were less likely to be satisfied with the surgery outcome at 1 year. Current smoking was associated with lower likelihood of achieving minimal clinically important difference in Patient-Reported Outcomes Measurement Information System, neck pain, arm pain, and EuroQol-5D at various time points. There was no difference in return-to-work status.

CONCLUSIONS

Our analysis suggests that smoking is negatively associated with functional improvement, patient satisfaction, and return-to-work after elective spine surgery.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

Smoking and degenerative spinal disease: A systematic review

Smoking is a major cause of morbidity and mortality worldwide and is responsible for the death of more than 8 million people per year globally. Through a systematic literature review, we aim to review the harmful effects of tobacco smoking on degenerative spinal diseases (DSD). DSD is a debilitating disease and there is a need to identify if smoking can be an attributable contender for the occurrence of this disease, as it can open up avenues for therapeutic options. Sources such as PubMed and Embase were used to review literature, maintaining tobacco smoking and spinal diseases as inclusion factors, excluding any article that did not explore this relationship. Risk of bias was assessed using analysis of results, sample size and methods and limitations. Upon review of the literature, tobacco smoking was found to be a major risk factor for the occurrence of DSDs, particularly lumbar spinal diseases. Smokers also experienced a greater need for surgery and greater postoperative wound healing complications, increased pain perception, delay in recovery and decreased satisfaction after receiving surgery. These effects were noted along the entire spine. Many mechanisms of action have been identified in the literature that provide plausible pictures of how smoking leads to spinal degeneration, exploring possible primary targets which can open up opportunities to develop potential therapeutic agents. More studies on cervical and thoracic spinal degeneration would be beneficial in identifying the effect of nicotine on these spinal levels. Some limitations included insufficient sample size, inconclusive evidence and lack of sufficient repeat studies. However, there appears to be a sufficient amount of research on smoking directly contributing to lumbar spinal pathology.

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Smoking is a risk factor for the occurence of degenerative spinal disease (DSD).

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There are numerous pathological mechanisms attributed to spinal pathology by smoking.

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Smoking appears to be a significant risk factor for lumbar DSDs, with smoke studies also suggesting its role in cervical DSDs.

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There is insufficient research on the effect of smoking on the thoracic spine.

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Smoking leads to worse outcomes and potential complications post-surgery, as well as increased pain perception and poorer subjective response post-surgery.

Pain During Sex Before and After Decompressive Surgery for Lumbar Spinal Stenosis: A Multicenter Observational Study

STUDY DESIGN

Observational multicenter study.

OBJECTIVE

The aim of this study was to evaluate changes in pain during sexual activity after surgery for lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

There are limited data available on sexual function in patients undergoing surgery for LSS.

METHODS

Data were retrieved from the Norwegian Registry for Spine Surgery. The primary outcome was change in pain during sexual activity at 1 year, assessed by item number eight of the Oswestry disability index questionnaire. Secondary outcome measures included Oswestry Disability Index, EuroQol-5D, and numeric rating scale scores for back and leg pain.

RESULTS

Among the 12,954 patients included, 9908 (76.5%) completed 1-year follow-up. At baseline 9579 patients (73.9%) provided information about pain during sexual activity, whereas 7424 (74.9%) among those with complete follow-up completed this item. Preoperatively 2528 of 9579 patients (26.4%) reported a normal sex-life without pain compared with 4294 of 7424 patients (57.8%) at 1 year. Preoperatively 1007 (10.5%) patients reported that pain prevented any sex-life, compared with 393 patients (5.3%) at 1 year. At baseline 7051 of 9579 patients (73.6%) reported that sexual activity caused pain, and among these 3145 of 4768 responders (66%) reported an improvement at 1 year. A multivariable regression analysis showed that having a life partner, college education, and working until time of surgery were predictors of improvement in pain during sexual activity. Current tobacco smoking, pain duration >12 months, previous spine surgery, and complications occurring within 3 months were negative predictors.

CONCLUSION

This study clearly demonstrates that a large proportion of patients undergoing surgery for LSS experienced an improvement in pain during sexual activity at 1 year.Level of Evidence: 2.

Pre-operative prognostic factors for walking capacity after surgery for lumbar spinal stenosis: a systematic review

BACKGROUND

Lumbar spinal stenosis (LSS) reduces walking and quality of life. It is the main indication for spinal surgery in older people yet 40% report walking disability post-operatively. Identifying the prognostic factors of post-operative walking capacity could aid clinical decision-making, guide rehabilitation and optimise health outcomes.

OBJECTIVE

To synthesise the evidence for pre-operative mutable and immutable prognostic factors for post-operative walking in adults with LSS.

DESIGN

Systematic review with narrative synthesis.

METHODS

Electronic databases (CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, OpenGrey) were searched for observational studies, evaluating factors associated with walking after surgery in adults receiving surgery for LSS from database inception to January 2020. Two reviewers independently evaluated studies for eligibility, extracted data and assessed risk of bias (Quality in Prognosis Studies). The Grading of Recommendations Assessment, Development and Evaluation method was used to determine level of evidence for each factor.

RESULTS

5526 studies were screened for eligibility. Thirty-four studies (20 cohorts, 9,973 participants, 26 high, 2 moderate, 6 low risk of bias) were included. Forty variables (12 mutable) were identified. There was moderate quality of evidence that pre-operative walking capacity was positively associated with post-operative walking capacity. The presence of spondylolisthesis and the severity of stenosis were not associated with post-operative walking capacity. All other factors investigated had low/very low level of evidence.

CONCLUSION

Greater pre-operative walking is associated with greater post-operative walking capacity but not spondylolisthesis or severity of stenosis. Few studies have investigated mutable prognostic factors that could be potentially targeted to optimise surgical outcomes.

The effect of smoking on achieving meaningful clinical outcomes one year after lumbar tubular microdecompression: a matched-pair cohort analysis

BACKGROUND CONTEXT

There has been a shift in the spine literature in reporting meaningful outcomes, including meaningful clinically important difference (MCID), after surgery. The evidence on the effect of tobacco smoking at the time of lumbar tubular microdecompression (LTMD) on meaningful outcomes is limited.

PURPOSE

To compare differences in 1-year functional outcomes and rates of achieving MCID between current smokers and non-smokers who underwent LTMD for lumbar spinal stenosis (LSS).

STUDY DESIGN

A nested case control study to compare the difference in patient reported outcomes (PROs) between smokers and non-smokers 1-year after undergoing LTMD.

PATIENT SAMPLE

This study included patients that underwent single level LTMD by a single surgeon between January 2014 through August 2019.

OUTCOME MEASURES

Preoperative and postoperative PROs were recorded using the questionnaires EQ-5D, Oswestry Disability Index (ODI), and the visual analog scale (VAS) for back pain and leg pain. The MCID was also used.

METHODS

Current tobacco smokers at the time of surgery were matched 1:2 to non-smokers by age (+/- 1year). Preoperative and postoperative functional scores were compared between the two groups using independent t-tests. Additionally, thresholds for achieving MCID were calculated for each individual functional score, and were compared using Fisher's exact test.

RESULTS

Of the 183 patients with 1-year follow-up who met inclusion criteria, 35 patients were identified as smokers and were matched to 70 non-smokers. No statistical differences were identified between age, BMI, or gender. Comparison of preoperative PROs showed no statistically significant differences between smokers and non-smokers (p>0.05 for all), while smokers had statistically lower EQ-5D (p<0.001) and higher ODI (p=0.05), VAS back (p=0.033), and VAS leg (p=0.03) score averages at a minimum of one year follow-up. Evaluation of meaningful outcomes demonstrated non-smokers had higher rates of achieving MCID on at least 1 threshold score as compared to smokers (98.5% vs. 91.1%; p=0.043).

CONCLUSIONS

Current smokers at the time of surgery have inferior postoperative EQ-5D scores, increased pain and disability, and lower odds of achieving the MCID at 1-year after undergoing LTMD when compared to patients without any smoking history.

Does Smoking Affect Short-Term Patient-Reported Outcomes After Lumbar Decompression?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The goal of this study was to determine how smoking status influences patient-reported outcome measurements (PROMs) in patients undergoing lumbar decompression surgery.

METHODS

Patients undergoing lumbar decompression between 1 to 3 levels at a single-center, academic hospital were retrospectively identified. Patients <18 years old, and those undergoing surgery for infection, trauma, tumor, or revision, with less than 12 months of follow-up were excluded. Patients were divided into 3 groups: (1) never smokers (NSs); (2) current smokers (CSs); and (3) former smokers (FSs). PROMs analyzed included the Physical Component Score and Mental Component Score of the Short Form-12 Health Survey, the Oswestry Disability Index, and Visual Analogue Scale Back and Leg pain scores. One-way ANOVA was used to compare preoperative and postoperative scores between smoking groups, and multiple linear regression analysis was performed to determine whether smoking status predicted change in each outcome score, controlling for factors such as age, sex, body mass index, and other clinical variables. A P value <.05 was considered to be significant.

RESULTS

A total of 195 patients were included in the final cohort, with 121 (62.1%) patients in the NS group, 22 (11.3%) in the CS group, and 52 (26.6%) in the FS group. There were no significant differences between groups at baseline or postoperatively. Smoking status was also not a significant predictor of change in any outcome scores over time on multivariate analysis.

CONCLUSION

These results suggest that smoking status does not significantly affect short-term complications or outcomes in patients undergoing lumbar decompression surgery.

The impact of multijoint symptoms on patient-reported disability following surgery for lumbar spine osteoarthritis

BACKGROUND CONTEXT

In the lumbar spine osteoarthritis (LS-OA) population having surgery for lumbar spinal stenosis (LSS) symptoms, a significant proportion of patients experience limited benefit following the intervention. Thus, identifying contributing factors to this is important. Individuals with OA often have multiple joint symptoms, yet this has received limited attention in this population.

PURPOSE

Document the occurrence of joint symptoms among patients undergoing surgery for LS-OA, and investigate the influence of these symptoms on disability postsurgery.

DESIGN

Prospective study of consecutive patients followed to 12-month postsurgery.

PATIENT SAMPLE

Patients undergoing surgery (decompression surgery, with or without fusion) for neurogenic claudication with or without back pain due to LSS with a primary pathology diagnosis of LS-OA.

OUTCOMES MEASURES

Patient self-reported: Oswestry Disability Index (ODI), completed pre- and 12-month postsurgery; and, completed presurgery, age, sex, education, smoking, comorbid conditions, opioid use, short/long-term disability, depression and anxiety symptoms, back and leg pain intensity, presence of spondylolisthesis, procedure, prior spine surgery, and joints with arthritis and "pain/stiffness/swelling most days of the month" indicated on a homunculus (a joint site count was derived).

ASSESSMENTS

Height and weight, used to calculate body mass index; timed-up-and-go performance-based test.

METHODS

Outcome of interest was achieving a clinically important improvement (CII) in ODI by 12-month postsurgery (yes/no). The association between joint site count and achieving a CII was examined by multivariable logistic regression analyses, adjusted for other measures.

RESULTS

In all, 165 patients were included. The mean age was 67 years (range: 44-90) and 47% were female. Seventy-seven percent reported 1+ joint site other than the back, 62% reported 2+, and 25% reported 4+. Among those achieving a CII, 21% had 4+ joint sites, compared with 31% among those not achieving a CII. Adjusted analyses: Increasing joint site count was associated with increasing risk (odds ratio [OR]: 1.32, 95% confidence interval [CI]: 1.05, 1.66) of not achieving a CII; for those with 4+ joints, adjusted probability of not achieving a CII exceeded 50%. Also associated with an increased risk of not achieving a CII was presurgery anxiety (OR: 2.97, 95% CI: 1.02, 8.65), opioid use (OR: 2.89, 95% CI: 1.07, 7.82), and worse back pain intensity score (OR: 1.27, 95% CI: 1.05, 1.53).

CONCLUSIONS

Multijoint involvement was highly prevalent in this LS-OA surgical sample. Its association with poorer postsurgery outcome supports a comprehensive approach to OA management and care. Knowledge of multijoint symptoms should inform patient education, shared decision-making, and recommendations for postsurgical rehabilitation and self-management strategies.

Pain During Sex Before and After Surgery for Lumbar Disc Herniation: A Multicenter Observational Study

STUDY DESIGN

Observational multicenter study.

OBJECTIVE

The aim of this study was to evaluate changes in pain during sexual activity after surgery for lumbar disc herniation (LDH).

SUMMARY OF BACKGROUND DATA

There are limited data available on sexual function in patients undergoing surgery for LDH.

METHODS

Data were retrieved from the Norwegian Registry for Spine Surgery. The primary outcome was change in pain during sexual activity at one year, assessed by item number eight of the Oswestry disability index (ODI) questionnaire. Secondary outcome measures included ODI, EuroQol-5D (EQ-5D), and numeric rating scale (NRS) scores for back and leg pain.

RESULTS

Among the 18,529 patients included, 12,103 (64.8%) completed 1-year follow-up. At baseline, 16,729 patients (90.3%) provided information about pain during sexual activity, whereas 11,130 (92.0%) among those with complete follow-up completed this item. Preoperatively 2586 of 16,729 patients (15.5%) reported that pain did not affect sexual activity and at 1 year, 7251 of 11,130 patients (65.1%) reported a normal sex-life without pain. Preoperatively, 2483 (14.8%) patients reported that pain prevented any sex-life, compared to 190 patients (1.7%) at 1 year. At baseline, 14,143 of 16,729 patients (84.5%) reported that sexual activity caused pain, and among these 7232 of 10,509 responders (68.8%) reported an improvement at 1 year. A multivariable regression analysis showed that having a life partner, college education, working until time of surgery, undergoing emergency surgery, and increasing ODI score were predictors of improvement in pain during sexual activity. Increasing age, tobacco smoking, increasing body mass index, comorbidity, back pain >12 months, previous spine surgery, surgery in two or more lumbar levels, and complications occurring within 3 months were negative predictors.

CONCLUSION

This study clearly demonstrates that a large proportion of patients undergoing surgery for LDH experienced an improvement in pain during sexual activity at 1 year.

LEVEL OF EVIDENCE

2.

Concomitant back and leg pain as predictors for trajectories of poor outcome after single level lumbar micro-decompression alone and with micro-discectomy: a study of 3,308 patients

BACKGROUND

Lumbar decompression is the commonest spinal intervention. One in four patients have suboptimal outcome postoperatively, however no large studies identified clear poor outcome predictors. The aim of this study was to study low back pain (LBP) as a predictor of poor outcome following lumbar micro-decompression.

METHODS

Prospectively collected spinal registry data was analysed for patients who underwent primary, single-level, decompression with or without discectomy at single spinal centre (2011-2017). Based on the response to the Likert global outcome question, we had two outcome groups (good & poor). Percentage of achievement of minimum clinically relevant change (MCRC) for Core Outcome Measures Index (COMI) score, LBP and leg pain (LP) was examined. A two-step approach was adopted. First, COMI score, LBP and LP visual analogue scales (VAS) trajectories were modelled using a discrete mixture model. Second, multinomial logistic regression was used to determine the association between variables and trajectories.

RESULTS

We included 3,308 patients with mean follow up (1.4 y). MCRC was achieved in COMI score in 63% of cases, 42% in LBP and 62% in LP. A three-group trajectory model was identified: large-improvement (LI) (n=980), moderate-improvement (MI) (n=1,364) and no-improvement (NI) (n=966) with 99.5%, 84.5% and 31.5% of patients presenting good outcome, respectively. Higher pre-operative LBP and COMI score and smoking were strongly associated with MI and NI. In addition, higher LP, post-operative surgical complications, previous surgery at same level, conservative treatment >6 months and anxiety/depression were associated with NI.

CONCLUSIONS

This is the first large-scale study reporting preoperative LBP severity, spinal stenosis and smoking as predictors for poor functional outcomes post lumbar decompression with or without discectomy. This is very useful while counselling patients for surgery to meet realistic expectations.

Preoperative Factors Predict Postoperative Trajectories of Pain and Disability Following Surgery for Degenerative Lumbar Spinal Stenosis

STUDY DESIGN

Longitudinal analysis of prospectively collected data.

OBJECTIVE

Investigate potential predictors of poor outcome following surgery for degenerative lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

LSS is the most common reason for an older person to undergo spinal surgery, yet little information is available to inform patient selection.

METHODS

We recruited LSS surgical candidates from 13 orthopedic and neurological surgery centers. Potential outcome predictors included demographic, health, clinical, and surgery-related variables. Outcome measures were leg and back numeric pain rating scales and Oswestry disability index scores obtained before surgery and after 3, 12, and 24 postoperative months. We classified surgical outcomes based on trajectories of leg pain and a composite measure of overall outcome (leg pain, back pain, and disability).

RESULTS

Data from 529 patients (mean [SD] age = 66.5 [9.1] yrs; 46% female) were included. In total, 36.1% and 27.6% of patients were classified as experiencing a poor leg pain outcome and overall outcome, respectively. For both outcomes, patients receiving compensation or with depression/depression risk were more likely, and patients participating in regular exercise were less likely to have poor outcomes. Lower health-related quality of life, previous spine surgery, and preoperative anticonvulsant medication use were associated with poor leg pain outcome. Patients with ASA scores more than two, greater preoperative disability, and longer pain duration or surgical waits were more likely to have a poor overall outcome. Patients who received preoperative chiropractic or physiotherapy treatment were less likely to report a poor overall outcome. Multivariable models demonstrated poor-to acceptable (leg pain) and excellent (overall outcome) discrimination.

CONCLUSION

Approximately one in three patients with LSS experience a poor clinical outcome consistent with surgical non-response. Demographic, health, and clinical factors were more predictive of clinical outcome than surgery-related factors. These predictors may assist surgeons with patient selection and inform shared decision-making for patients with symptomatic LSS.

LEVEL OF EVIDENCE

2.

Relationship of lumbar disc degeneration with hemoglobin value and smoking

BACKGROUND/OBJECTIVE

Although a number of studies report an important effect of smoking on disc degeneration and herniation, others did not identify such a relationship. The purpose of this study was to assess the relationship of lumbar disc degeneration with hemoglobin value and smoking.

METHODS

The study included 200 adult patients who presented to the neurosurgery polyclinic with a complaint of back pain. Smoking habits were classified as "smoking for more than 10 years", "smoking for less than 10 years", and "not smoking". Lumbar disc degeneration was classified on modified Pfirrmann score according to lumbar MR images. Degeneration level was compared according to smoking group on Kruskal-Wallis test. The relationship between hemoglobin value and disc degeneration according to smoking group was assessed on the Spearman correlation coefficient.

RESULTS

Disc degeneration values were significantly different between groups in L5-S1, L4-L5 and L3-L4 (P=0.018, P=0.012, P=0.038). Degeneration levels in L5-S1 in those who did not smoke were significantly lower than in those who smoked for both less and more than 10 years (P=0.048, P=0.022). No significant differences were found in degeneration level between those who smoked for more versus less than 10 years. For L3-L4 degeneration, there was a significant relationship with hemoglobin value in the group that did not smoke and in the group that smoked for more than 10 years (r=-0.395; P=0.009, r=0.329; P=0.018).

CONCLUSION

This study found that, when risk factors such as systemic disease, heavy working conditions, obesity, trauma and family history were excluded, smoking increased lumbar disc degeneration. In addition, chronic smoking was found to increase hemoglobin values.

Microdiscectomy for Lumbar Disc Herniation: A Single-Center Observational Study

OBJECTIVE

To examine outcomes and complications following first-time lumbar microdiscectomy.

METHODS

Prospective data for patients operated on between May 2007 and July 2016 were obtained from the Norwegian Registry for Spine Surgery. The primary outcome was change in Oswestry Disability Index (ODI) score at 1 year. Secondary endpoints were change in quality of life measured with EuroQol 5 Dimensions, back and leg pain measured with numeric rating scales, and perioperative complications within 3 months of surgery.

RESULTS

For all enrolled patients (N = 1219) enrolled, mean improvement in ODI at 1 year was 33.3 points (95% confidence interval [CI] 31.7 to 34.9, P < 0.001). Mean improvement in EuroQol 5 Dimensions at 1 year of 0.52 point (95% CI 0.49 to 0.55, P < 0.001) represents a large effect size (Cohen's d = 1.6). Mean improvements in back pain and leg pain numeric rating scales were 3.9 points (95% CI 3.6 to 4.1, P < 0.001) and 5.0 points (95% CI 4.8 to 5.2, P < 0.001), respectively. There were 18 surgical complications in 1219 patients and 63 medical complications in 846 patients. The most common complication was micturition problems at 3 months following surgery (n = 25, 2.1%). In multivariate analysis, ODI scores of 21-40 (hazard ratio [HR] 14.5, 95% CI 1.1 to 27.9, P = 0.035), 41-60 (HR 27.5, 95% CI 13.4 to 41.7, P < 0.001), 61-80 (HR 47.4, 95% CI 33.4 to 61.4, P < 0.001) and >81 (HR 66.7, 95% CI 51.1 to 82.2, P < 0.001) were identified as positive predictors for ODI improvement at 1 year, whereas age ≥65 (HR -0.9, 95% CI -0.3 to -1.5, P = 0.004) was identified as a negative predictor for ODI improvement.

CONCLUSIONS

Microdiscectomy for lumbar disc herniation is an effective and safe treatment.

Development and Validation of a Prediction Model for Pain and Functional Outcomes After Lumbar Spine Surgery

Importance

Functional impairment and pain are common indications for the initiation of lumbar spine surgery, but information about expected improvement in these patient-reported outcome (PRO) domains is not readily available to most patients and clinicians considering this type of surgery.

Objective

To assess population-level PRO response after lumbar spine surgery, and develop/validate a prediction tool for PRO improvement.

Design, Setting, and Participants

This statewide multicenter cohort was based at 15 Washington state hospitals representing approximately 75% of the state's spine fusion procedures. The Spine Surgical Care and Outcomes Assessment Program and the survey center at the Comparative Effectiveness Translational Network prospectively collected clinical and PRO data from adult candidates for lumbar surgery, preoperatively and postoperatively, between 2012 and 2016. Prediction models were derived for PRO improvement 1 year after lumbar fusion surgeries on a random sample of 85% of the data and were validated in the remaining 15%. Surgical candidates from 2012 through 2015 were included; follow-up surveying continued until December 31, 2016, and data analysis was completed from July 2016 to April 2017.

Main Outcomes and Measures

Functional improvement, defined as a reduction in Oswestry Disability Index score of 15 points or more; and back pain and leg pain improvement, defined a reduction in Numeric Rating Scale score of 2 points or more.

Results

A total of 1965 adult lumbar surgical candidates (mean [SD] age, 61.3 [12.5] years; 944 [59.6%] female) completed baseline surveys before surgery and at least 1 postoperative follow-up survey within 3 years. Of these, 1583 (80.6%) underwent elective lumbar fusion procedures; 1223 (77.3%) had stenosis, and 1033 (65.3%) had spondylolisthesis. Twelve-month follow-up participation rates for each outcome were between 66% and 70%. Improvements were reported in function, back pain, and leg pain at 12 months by 306 of 528 surgical patients (58.0%), 616 of 899 patients (68.5%), and 355 of 464 patients (76.5%), respectively, whose baseline scores indicated moderate to severe symptoms. Among nonoperative patients, 35 (43.8%), 47 (53.4%), and 53 (63.9%) reported improvements in function, back pain, and leg pain, respectively. Demographic and clinical characteristics included in the final prediction models were age, sex, race, insurance status, American Society of Anesthesiologists score, smoking status, diagnoses, prior surgery, prescription opioid use, asthma, and baseline PRO scores. The models had good predictive performance in the validation cohort (concordance statistic, 0.66-0.79) and were incorporated into a patient-facing, web-based interactive tool (https://becertain.shinyapps.io/lumbar_fusion_calculator).

Conclusions and Relevance

The PRO response prediction tool, informed by population-level data, explained most of the variability in pain reduction and functional improvement after surgery. Giving patients accurate information about their likelihood of outcomes may be a helpful component in surgery decision making.

Comparing different chronic preoperative opioid use definitions on outcomes after spine surgery

BACKGROUND CONTEXT

No consensus exists for defining chronic preoperative opioid use. Most spine studies rely solely on opioid duration to stratify patients into preoperative risk categories.

PURPOSE

The purpose of this study is to compare established opioid definitions that contain both duration and dosage to opioid models that rely solely on duration, including the CDC Guideline for Prescribing Opioids for Chronic Pain, in patients undergoing spine surgery.

STUDY DESIGN

This was a retrospective cohort study that used opioid data from the Tennessee Controlled Substance Monitoring Database and prospective clinical data from a single-center academic spine registry.

PATIENT SAMPLE

The study cohort consisted of 2,373 patients who underwent elective spine surgery for degenerative conditions between January 2011 and February 2017 and who completed a follow-up assessment at 12 months after surgery.

OUTCOME MEASURES

Postoperative opioid use and patient-reported satisfaction (NASS Satisfaction Scale), disability (Oswestry/Neck Disability Index), and pain (Numeric Rating Scale) at 12 month follow-up.

METHODS

Six different chronic preoperative opioid use variables were created based on the number of times a prescription was filled and/or daily morphine milligram equivalent for the one year before surgery. These variables defined chronic opioid use as 1) most days for > 3 months (CDC), 2) continuous use for ≥ 6 months (Schoenfeld), 3) >4,500 mg for at least 9 months (Svendsen wide), 4) >9,000 mg for 12 months (Svendsen intermediary), 5) >18,000 mg for 12 months (Svendsen strict), 6) low-dose chronic (1-36 mg for >91 days), medium-dose chronic (36-120 mg for >91 days), and high-dose chronic (>120 mg for >91 days) (Edlund). Multivariable regression models yielding C-index and R² values were used to compare chronic preoperative opioid use definitions by postoperative outcomes, adjusting for type of surgery.

RESULTS

Chronic preoperative opioid use was reported in 470 to 725 (19.8% to 30.6%) patients, depending on definition. The Edlund definition, accounting for duration and dosage, had the highest predictive ability for postoperative opioid use (77.5%), followed by Schoenfeld (75.7%), CDC (72.6%), and Svendsen (59.9% to 72.5%) definitions. A combined Edlund and Schoenfeld duration and dosage definition in post-hoc analysis, that included 3 and 6 month duration cut-offs, performed the best overall with a C-index of 78.4%. Both Edlund and Schoenfeld definitions explained similar amounts of variance in satisfaction, disability, and pain (4.2% to 8.5%). Svendsen and CDC definitions demonstrated poorer performance for patient-reported outcomes (1.4% to 7.2%).

CONCLUSIONS

The Edlund definition is recommended for identifying patients at highest risk for postoperative opioid use. When opioid dosage is unavailable, the Schoenfeld definition is a reasonable choice with similar predictive ability. For patient-reported outcomes, either the Edlund or Schoenfeld definition is recommended. Future work should consider combing dosage and duration, with 3 and 6 month cutoffs, into chronic opioid use definitions.

Comparative effectiveness and prognostic factors for outcome of surgical and non-surgical management of lumbar spinal stenosis in an elderly population: protocol for an observational study

INTRODUCTION

Lumbar spinal stenosis is a common cause of low back and leg pain in the elderly and affects both physical activity and quality of life. First-line treatments are non-surgical options but if unsuccessful, surgery is advocated. The literature is not clear as to the outcome of surgery compared with non-surgical treatment, and the optimal time for surgery is not explicit. This observational study is designed to investigate the course of treatment, compare effectiveness of surgical and non-surgical management in patients with lumbar spinal stenosis and identify prognostic factors for outcome in the context of current clinical practice.

MATERIALS AND ANALYSIS

Prospectively registered data on treatment, outcome and patient characteristics are collected from nationwide registers on health and social issues, a clinical registry of people with chronic back pain and hospital medical records. Primary outcome is change in physical function measured by the Zurich Claudication Questionnaire. Secondary outcomes are changes in symptom severity, pain-related function, health-related quality of life and general self-efficacy. Outcomes are assessed at baseline and 6 and 12 months. Outcomes at 12 months will be compared for patients who undergo surgery for lumbar spinal stenosis and patients managed non-surgically, using different analytical approaches. Prespecified prognostic factors of interest at baseline include treatment allocation, back and leg pain intensity, comorbidity, duration of symptoms, pretreatment function, self-rated health, income, general self-efficacy and MRI-graded severity of central stenosis.

ETHICS AND DISSEMINATION

The study has been evaluated by the Regional Committees on Health Research for Southern Denmark (S-20172000-200) and notified to the Danish Data Protection Agency (18/22336). All participants provide consent. Findings will be disseminated in peer-reviewed publications and presented at national and international conferences according to the Strengthening the Reporting of Observational Studies in Epidemiology and Prognosis Research Strategy statements. Potential sources of bias will be addressed using Risk of Bias in Non-randomised Studies of Interventions.

TRIAL REGISTRATION NUMBER

NCT03548441; Pre-results.

Prognostic function to estimate the probability of meaningful clinical improvement after surgery - Results of a prospective multicenter observational cohort study on patients with lumbar spinal stenosis

BACKGROUND

Approximately two thirds of patients with lumbar spinal stenosis (LSS) who undergo surgical treatment benefit from the surgery. The objective of this study was to derive a prognostic probability function (PPF) to identify patients with a high probability of post-surgical improvement because there is currently no method available.

METHODS

In this multicenter, prospective, observational study, we collected data from eight medical centers in Switzerland in which patients underwent surgery for LSS. The endpoints were meaningful clinically important differences (MCID) in pain and disability one year after baseline. We developed a PPF named PROCESS (PostopeRative OutComE Spinal Stenosis), based on a large set of prognostic indicators extracted from the literature. The PPF was derived using data from a random subset of two thirds of the patients and validated in the remaining third. We addressed overfitting by shrinking the regression coefficients. The area under the ROC curve (AUC) and calibration determined the accuracy of the PPF.

RESULTS

In this study, 452 LSS patients received surgery. 73% of the 300 patients in the derivation subset reached an MCID in pain and 68% reached an MCID in disability. The corresponding values were 70% and 63% in the validation subset, respectively. In the derivation subsample, the AUC was 0.64 (95% CI 0.57 to 0.71) for of the PPF predicting MCID in pain and 0.71 (0.64 to 0.77) for MCID in disability, after shrinkage. The corresponding numbers were 0.62 (0.52 to 0.72) and 0.70 (0.60 to 0.79) in the validation subsample, and the PPF showed good calibration.

CONCLUSIONS

Surgical treatment for patients with lumbar spinal stenosis is being performed with increasing frequency. PROCESS is conditional on the individual pattern of preoperatively available prognostic indicators, and may be helpful for clinicians in counselling patients and in guiding the discussion on individual treatment decision in the era of personalized medicine.

The Effect of Tobacco Smoking on Musculoskeletal Health: A Systematic Review

This systematic review explored associations between smoking and health outcomes involving the musculoskeletal system. AMSTAR criteria were followed. A comprehensive search of PubMed, Web of Science, and Science Direct returned 243 articles meeting inclusion criteria. A majority of studies found smoking has negative effects on the musculoskeletal system. In research on bones, smoking was associated with lower BMD, increased fracture risk, periodontitis, alveolar bone loss, and dental implant failure. In research on joints, smoking was associated with increased joint disease activity, poor functional outcomes, and poor therapeutic response. There was also evidence of adverse effects on muscles, tendons, cartilage, and ligaments. There were few studies on the musculoskeletal health outcomes of secondhand smoke, smoking cessation, or other modes of smoking, such as waterpipes or electronic cigarettes. This review found evidence that suggests tobacco smoking has negative effects on the health outcomes of the musculoskeletal system. There is a need for further research to understand mechanisms of action for the effects of smoking on the musculoskeletal system and to increase awareness of healthcare providers and community members of the adverse effects of smoking on the musculoskeletal system.

Lumbar Microdiscectomy in Obese Patients: A Multicenter Observational Study

OBJECTIVE

To evaluate the association between obesity and outcomes after microdiscectomy for lumbar disc herniation.

METHODS

The primary outcome measure was change in Oswestry Disability Index (ODI) at 1 year after surgery. Obesity was defined as body mass index (BMI) ≥30. Prospective data were retrieved from the Norwegian Registry for Spine Surgery.

RESULTS

We enrolled 4932 patients, 4018 nonobese and 914 obese. For patients with complete 1-year follow-up (n = 3381) the mean improvement in ODI was 31.2 points (95% confidence interval 30.4-31.9, P < 0.001). Improvement in ODI was 31.4 points in nonobese and 30.1 points in obese patients (P = 0.182). Obese and nonobese patients were as likely to achieve a minimal clinically important difference (84.2 vs. 82.7%, P = 0.336) in ODI (≥10 points improvement). Obesity was identified as a negative predictor for ODI improvement in a multiple regression analysis (BMI 30-34.99; P < 0.001, BMI ≥35; P = 0.029). Obese and nonobese patients experienced similar improvement in Euro-Qol-5 scores (0.48 vs. 0.49 points, P = 0.441) as well as back pain (3.7 vs. 3.5 points, P = 0.167) and leg pain (4.7 vs. 4.8 points, P = 0.654), as measured by the Numeric Rating Scale. Duration of surgery was shorter for nonobese patients (55.7 vs. 65.3 minutes, P ≤ 0.001). Nonobese patients experienced fewer complications compared with obese patients (6.1% vs. 8.3%, P = 0.017). Obese patients had slightly longer hospital stays (2.0 vs. 1.8 days, P = 0.004).

CONCLUSIONS

Although they had more minor complications, obese individuals experienced improvement after lumbar microdiscectomy for lumbar disc herniation similar to that of nonobese individuals.

Patient characteristics of smokers undergoing lumbar spine surgery: an analysis from the Quality Outcomes Database

OBJECTIVE

In this analysis the authors compare the characteristics of smokers to nonsmokers using demographic, socioeconomic, and comorbidity variables. They also investigate which of these characteristics are most strongly associated with smoking status. Finally, the authors investigate whether the association between known patient risk factors and disability outcome is differentially modified by patient smoking status for those who have undergone surgery for lumbar degeneration.

METHODS

A total of 7547 patients undergoing degenerative lumbar surgery were entered into a prospective multicenter registry (Quality Outcomes Database [QOD]). A retrospective analysis of the prospectively collected data was conducted. Patients were dichotomized as smokers (current smokers) and nonsmokers. Multivariable logistic regression analysis fitted for patient smoking status and subsequent measurement of variable importance was performed to identify the strongest patient characteristics associated with smoking status. Multivariable linear regression models fitted for 12-month Oswestry Disability Index (ODI) scores in subsets of smokers and nonsmokers was performed to investigate whether differential effects of risk factors by smoking status might be present.

RESULTS

In total, 18% (n = 1365) of patients were smokers and 82% (n = 6182) were nonsmokers. In a multivariable logistic regression analysis, the factors significantly associated with patients’ smoking status were sex (p < 0.0001), age (p < 0.0001), body mass index (p < 0.0001), educational status (p < 0.0001), insurance status (p < 0.001), and employment/occupation (p = 0.0024). Patients with diabetes had lowers odds of being a smoker (p = 0.0008), while patients with coronary artery disease had greater odds of being a smoker (p = 0.044). Patients’ propensity for smoking was also significantly associated with higher American Society of Anesthesiologists (ASA) class (p < 0.0001), anterior-alone surgical approach (p = 0.018), greater number of levels (p = 0.0246), decompression only (p = 0.0001), and higher baseline ODI score (p < 0.0001). In a multivariable proportional odds logistic regression model, the adjusted odds ratio of risk factors and direction of improvement in 12-month ODI scores remained similar between the subsets of smokers and nonsmokers.

CONCLUSIONS

Using a large, national, multiinstitutional registry, the authors described the profile of patients who undergo lumbar spine surgery and its association with their smoking status. Compared with nonsmokers, smokers were younger, male, nondiabetic, nonobese patients presenting with leg pain more so than back pain, with higher ASA classes, higher disability, less education, more likely to be unemployed, and with Medicaid/uninsured insurance status. Smoking status did not affect the association between these risk factors and 12-month ODI outcome, suggesting that interventions for modifiable risk factors are equally efficacious between smokers and nonsmokers.

Does smoking affect the outcomes of lumbar decompression surgery?

Introduction: Lumbar decompressions and micro-discectomies are commonly performed non-complex spinal surgeries that do not involve the insertion of metalwork into the spine and are done for symptomatic disc prolapse and lumbar spinal stenosis, whereas complex-spinal surgery does require metalwork [1]. Studies of complex-spinal surgeries show that smoking has a significant negative impact on the outcome of the surgery [2] therefore, the cessation of smoking is advised prior to surgery [3]. There are evidences in the literature supportive as well as opposing this statement about continued smoking and poor outcome of decompressive spinal surgeries.

Methods: We retrospectively reviewed 143 consecutive patients who have had either a micro-discectomy or a micro-decompression.

Results: We found no statistical difference between smokers and non-smokers in the outcomes of lumbar decompression surgery. Both groups improved equally and significantly in terms of back pain, leg pain and functions. Out of 143 patients, only 2% more non-smokers had improved leg pain compared to smokers, 1% less non-smokers had improved back pain and 2% more non-smokers had an improved Oswestry Disability Index (ODI) score.

Discussion: We recommend that it is important to surgically treat both smokers and non-smokers in need of a lumbar spinal decompression.

Surgery for Herniated Lumbar Disc in Daily Tobacco Smokers: A Multicenter Observational Study

OBJECTIVE

To compare clinical outcomes at 1 year following single-level lumbar microdiscectomy in daily tobacco smokers and nonsmokers.

METHODS

Data were collected through the Norwegian Registry for Spine Surgery. The primary endpoint was a change in the Oswestry Disability Index (ODI) at 1 year. Secondary endpoints were change in quality of life measured with EuroQol 5 Dimensions (EQ-5D), leg and back pain measured with a numerical rating scale (NRS), and rates of surgical complications.

RESULTS

A total of 5514 patients were enrolled, including 3907 nonsmokers and 1607 smokers. A significant improvement in ODI was observed for the entire cohort (mean, 31.1 points; 95% confidence interval [CI], 30.4-31.8; P < 0.001). Nonsmokers experienced a greater improvement in ODI at 1 year compared with smokers (mean, 4.1 points; 95% CI, 2.5-5.7; P < 0.001). Nonsmokers were more likely to achieve a minimal important change (MIC), defined as an ODI improvement of ≥10 points, compared with smokers (85.5% vs. 79.5%; P < 0.001). Nonsmokers experienced greater improvements in EQ-5D (mean difference, 0.068; 95% CI, 0.04-0.09; P < 0.001), back pain NRS (mean difference, 0.44; 95% CI, 0.21-0.66; P < 0.001), and leg pain NRS (mean difference, 0.54; 95% CI, 0.31-0.77; P < 0.001). There was no difference between smokers and nonsmokers in the overall complication rate (6.2% vs. 6.7%; P = 0.512). Smoking was identified as a negative predictor for ODI change in a multiple regression analysis (P < 0.001).

CONCLUSIONS

Nonsmokers reported a greater improvement in ODI at 1 year following microdiscectomy, and smokers were less likely to experience an MIC. Nonetheless, significant improvement was also found among smokers.

Predictors of Long-term Opioid Use Following Lumbar Fusion Surgery

STUDY DESIGN

A population-based retrospective cohort study.

OBJECTIVE

The aim of this study was to examine risk factors for long-term opioid use following lumbar spinal fusion surgery in a nationally representative cohort of commercially insured adults.

SUMMARY OF BACKGROUND DATA

Opioid prescription rates for the management of low back pain have more than doubled in the US over the past decade. Although opioids are commonly used for the management of pain following lumbar spinal fusion surgery, to date, no large-scale nationally representative studies have examined the risk factors for long-term opioid use following such surgical intervention.

METHODS

Using one of the nation's largest commercial insurance databases, we conducted a retrospective cohort study of 8377 adults, aged 21 to 63 years, who underwent lumbar spinal fusion surgery between January 1, 2009, and December 31, 2012. Long-term opioid use was defined as ≥365 days of filled opioid prescriptions in the 24 months following lumbar fusion. Multivariable logistic regression was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals for the risk of long-term opioid use following lumbar fusion.

RESULTS

After adjusting for covariates, the following factors were associated with an increased risk of long-term opioid use following surgery: duration of opioid use in the year before lumbar surgery [Referent (0 days); Quartile 1 (1-22 days) OR = 2.27, 95% CI = 1.48-3.49; Quartile 2 (23-72 days): OR = 5.94, 95% CI = 4.00-8.83; Quartile 3: (73-250 days) OR = 25.31, 95% CI = 17.26-37.10; Quartile 4 (≥250 days) OR = 219.95, 95% CI = 148.53-325.71)], refusion surgery (OR = 1.32, 95% CI = 1.02-1.72), and diagnosis of depression (OR = 1.43, 95% CI = 1.18-1.74). Receipt of anterior fusion was associated with a modest decrease in the risk of long-term opioid use (OR = 0.79, 95% CI = 0.63-0.99).

CONCLUSION

These findings may provide clinically relevant information to physicians, patients, and their families regarding the risk factors for opioid dependence following lumbar fusion surgery.

LEVEL OF EVIDENCE

3.

The Effects of Smoking and Smoking Cessation on Spine Surgery: A Systematic Review of the Literature

Study Design Literature review. Objective The aim of this literature review was to detail the effects of smoking in spine surgery and examine whether perioperative smoking cessation could mitigate these risks. Methods A review of the relevant literature examining the effects of smoking and cessation on surgery was conducted using PubMed, Google Scholar, and Cochrane databases. Results Current smokers are significantly more likely to experience pseudarthrosis and postoperative infection and to report lower clinical outcomes after surgery in both the cervical and lumbar spines. Smoking cessation can reduce the risks of these complications depending on both the duration and timing of tobacco abstinence. Conclusion Smoking negatively affects both the objective and subjective outcomes of surgery in the lumbar and cervical spine. Current literature supports smoking cessation as an effective tool in potentially mitigating these unwanted outcomes. Future investigations in this field should be directed toward developing a better understanding of the complex relationship between smoking and poorer outcomes in spine surgery as well as developing more efficacious cessation strategies.

Does surgical technique influence clinical outcome after lumbar spinal stenosis decompression? A comparative effectiveness study from the Norwegian Registry for Spine Surgery

INTRODUCTION

The aim of this study was to compare the clinical outcome of spinal process osteotomy with two other midline-retaining methods, bilateral laminotomy and unilateral laminotomy with crossover, among patients undergoing surgery for lumbar spinal stenosis.

METHODS

This cohort study was based on data from the Norwegian Registry for Spine Surgery (NORspine). Patients were operated on between 2009 and 2013 at 31 Norwegian hospitals. The patients completed questionnaires at admission for surgery, and after 3 and 12 months. The Oswestry Disability Index (ODI) was the primary outcome. Secondary outcomes were duration of surgery and hospital stay, Numeric Rating Scale (NRS) for back pain and leg pain, and EQ-5D and EQ-VAS. The patients were classified into one of three treatment groups according to the surgery they had received, and a propensity score was utilized to minimize bias. The three treatment groups were divided into subgroups based on Propensity Scores, and the statistical analyses were performed with and within the Propensity Score stratified subgroups.

RESULTS

103 patients had spinal process osteotomy, 966 patients had bilateral laminotomy, and 462 patients had unilateral laminotomy with crossover. Baseline clinical scores were similar in the three groups. There were no differences in improvement after 3 and 12 months between treatment groups. At 12 months, mean ODI improvement was 15.2 (SD 16.7) after spinous process osteotomy, 16.9 (SD 17.0) after bilateral laminotomy, and 16.7 (SD 16.9) after unilateral laminotomy with crossover. There were no differences in the secondary clinical outcomes or complication rates. Mean duration of surgery was greatest for spinal process osteotomy (p < 0.05). Length of stay was 2.1 days (SD 2.1) in the bilateral laminotomy group, 3.5 (SD 2.4) days for unilateral laminotomy, and 6.9 days (SD 4.1) for spinous process osteotomy group (p < 0.05).

CONCLUSION

In a propensity scored matched cohort, there were no differences in the clinical outcome 12 months after surgery for lumbar spinal stenosis performed using the three different posterior decompression techniques. Bilateral laminotomy had shortest duration of surgery and shortest length of hospital stay. Surgical technique does not seem to affect clinical outcome after three different midline-retaining posterior decompression techniques.

Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis: long-term results and predictive factors

BACKGROUND

The microsurgical unilateral laminotomy (MUL) technique for bilateral decompression of lumbar spinal stenosis (LSS) is a less destabilizing alternative to laminectomy and leads to good short-term outcomes. However, little is known about the long-term results including predictive factors.

METHODS

Medical records of patients who underwent MUL for LSS decompression between 2005 and 2010 were reviewed, and a questionnaire was distributed to complement the long-term outcome data. The study population consisted of 176 patients including 17 patients with stable grade I spondylolisthesis. Complications and reoperations were meticulously analyzed. Clinical outcome was measured using a modified Prolo scale and was further dichotomized in good vs. poor outcome. Predictive factors were obtained from uni- and multivariate analyses.

RESULTS

The median age of the cohort was 70.0 years and the follow-up 71.7 months. Complications occurred in 5.1 % of the patients. The overall reoperation rate was 17.0 %, including surgery, which was exclusively performed at other levels in 4.0 %. The reoperation rate for fusion was 4.5 %. Good neurogenic claudication outcome faded from 98.3 % at hospital discharge to 47.2 % at 6 years. Multivariate analysis identified previous lumbar operation as a potential independent predictor of a reoperation; potential independent predictors of poor long-term claudication outcome were older age, female gender, higher body mass index (BMI) and tobacco smoking.

CONCLUSIONS

In our experience, the long-term reoperation rate after MUL for LSS is not negligible and higher in previously operated patients. It seems like the good initial clinical results after MUL may fade over time, and several patient-related predictive factors including potentially modifiable obesity and tobacco smoking seem to play an important role.

Short- and long-term effects of smoking on pain and health-related quality of life after non-instrumented lumbar spine surgery

OBJECTIVES

A myriad of negative bodily health effects related to tobacco smoking is known while its detrimental effects on the spine in particular are less defined. The goal of the current study is to compare long-term outcome between smokers and non-smokers after non-instrumented lumbar spine surgery.

PATIENTS AND METHODS

Prospective observational study on n=172 consecutive patients undergoing non-instrumented spine surgery for lumbar disc herniation (LDH) or lumbar spinal stenosis (LSS) with a follow-up (FU) of 4.5 years. Patients were dichotomized according to their smoking status at the time of surgery. Back pain and health-related quality of life (HRQoL) were assessed using the visual analogue scale (VAS) and the Short-Form (SF)-12. Any subsequent lumbar spine surgeries since the index surgery were registered. Logistic regression analysis was used to estimate the effect size of the relationship between smoking and the responder status to surgery in terms of pain and HRQoL-metrics.

RESULTS

Complete FU data was available for n=29 (55%) smokers and n=75 (63%) non-smokers. At discharge, 1 month, 1 year and 4.5 years, smokers were as likely as non-smokers to achieve a favourable response to surgery in terms of VAS back pain and the SF-12 mental and physical component scale metric. A subgroup analysis on active smokers throughout the entire study interval did not find an inferior responder rate than in never-smokers. A trend for additional lumbar spine surgery performed in 17.2% of the smoking and 8.2% of the non-smoking patients during FU was observed (OR 2.39, 95% CI 0.67-8.57, p=0.179).

CONCLUSION

Up to 4.5 years following non-instrumented lumbar spine surgery, there was no difference in the pain or HRQoL-responder status of smokers and non-smokers. Smokers may be more likely to undergo re-do surgery in the long term, but more data is needed to confirm this statistical trend.