Global Spine Journal

Retrospective radiographic review.

Investigate and quantify transverse pedicle angle (TPA), the medial-to-lateral pedicle angulation, and its potential association with pelvic incidence (PI) in patients with isthmic lumbar spondylolisthesis (ISLS) and compare to those with degenerative lumbar spondylolisthesis (DSLS) and controls.

A total of 200 patients (64 ISLS, 70 DSLS, 66 control) were included. TPA was calculated at the L3-5 vertebral levels using axial computed tomography slices. PI was measured on lateral radiographs. Two independent observers completed the measurements. As a sensitivity analysis, TPA was also measured at the most cranial and caudal aspects of the L3-5 vertebral levels of a subset of participants (29 ISLS, 31 DSLS, 35 control) and the cranial to caudal change (ΔTPA) was calculated.

TPA values (mean ± SD) at L4 and L5 for ISLS (L4: 17.3° ± 3.7°, L5: 26.0° ± 5.2°) were significantly higher than those for the DSLS (L4: 14.3° ± 3.8°, L5: 22.2° ± 5.0°) and control (L4: 14.5° ± 3.9°, L5: 20.7° ± 3.8°) groups. TPA in the DSLS group was significantly higher than controls at L5, but not L4. High PI predicted wider TPA at L5 in both DSLS and ISLS. ΔTPA (mean ± SD) increased sequentially proceeding through the L3-5 spinal levels for the ISLS (L3: 6.8° ± 4.4°, L4: 8.7° ± 5.2°, L5: 15.6° ± 9.0°), DSLS (L3: 8.2° ± 6.0°, L4: 8.3° ± 5.9°, L5: 18.3° ± 7.2°), and control (L3: 6.8° ± 4.4°, L4: 8.2° ± 4.7°, L5: 17.7° ± 7.0°) groups.

TPA was significantly increased in ISLS compared with DSLS and controls. High PI significantly predicted high TPA at the L5 vertebral level in ISLS and DSLS. ΔTPA increased sequentially proceeding through the lumbar spine across groups.

Prospective cohort.

To investigate whether intraoperative neuromonitoring (IONM) positive changes affect functional outcome after surgical intervention for myeloradiculopathy secondary to cervical compressive pathology (cervical compressive myelopathy).

Twenty-eight patients who underwent cervical spine surgery with IONM for compressive myeloradiculopathy were enrolled. During surgery motor-evoked potential (MEP) and somatosensory evoked potential (SSEP) at baseline and before and after decompression were documented. A decrease in latency >10% or an increase in amplitude >50% was regarded as a “positive changes.” Patients were divided into subgroups based on IONM changes: group A (those with positive changes) and group B (those with no change or deterioration). Nurick grade and modified Japanese Orthopaedic Association (mJOA) score were evaluated before and after surgery.

Nine patients (32.1%) showed improvement in MEP. The mean preoperative Nurick grade and mJOA score of group A and B were (2.55 ± 0.83 and 11.11 ± 1.65) and (2.47 ± 0.7 and 11.32 ± 1.24), respectively. The mean postoperative Nurick grade of groups A and B at 6 months was 1.55 ± 0.74 and 1.63 ± 0.46, respectively, and this difference was not significant. The mean postoperative mJOA score of groups A and B at 6 months was 14.3 ± 1.03 and 12.9 ± 0.98, respectively, and this difference was statistically significant (P = .011). Spearman correlation coefficient showed significant positive correlation between the IONM change and the mJOA score at 6 months postoperatively (r = 0.47; P = .01).

Our study shows that impact of positive changes in MEP during IONM reflect in functional improvement at 6 months postoperatively in cervical compressive myelopathy patients.

Retrospective cohort study.

The purpose of this study was to compare outcomes between different treatment modalities for metastatic disease with indeterminate instability (Spinal Instability Neoplastic Score [SINS] 7-12).

We retrospectively reviewed neurologically intact patients treated for spinal metastatic disease with a SINS of 7 to 12. The cohort was stratified by treatment approach: external beam radiation therapy alone (EBRT), surgery + EBRT (S+E), and cement augmentation + EBRT (K+E). Kaplan-Meier analysis was used to assess differences in length of survival (LOS) and ability to ambulate at time of death. Multivariate analysis was performed to assess adjusted LOS and ability to ambulate at time of death.

The cohort included 211 patients, S+E (n = 57), EBRT (n = 128), and K+E (n = 27). In the S+E group, the median LOS was 430 days, which was statistically longer than the median LOS for the EBRT group (121 days) and the K+E group (169 days). In the S+E group, 52 patients (91.2%) and in the K+E group 24 patients (92.3%) retained the ability to ambulate at their time of death compared to 99 patients (77.3%) of the EBRT patients (P = .01). The overall rate of revision treatment at the spinal level initially treated was 17.5%, S+E (15.8%), EBRT (20.3%), and K+E (7.7%).

The length of survival, ability to maintain ambulatory ability, and revision treatment rates were all improved following surgical management and radiation therapy compared to radiation therapy alone. The authors’ conclusion from these results are that patients with indeterminate spinal instability should be discussed in a multidisciplinary setting for the need of spinal stabilization in addition to radiation therapy.

Bibliometric analysis.

With the increasing literature of spine surgery, some pioneering research studies have had a significant impact on the field of lumbar spinal stenosis (LSS). The objective of the authors was to identify and analyze the most frequently cited 100 articles in this field.

Web of Science was searched to identify 100 top-cited articles related to LSS from 2000 to 2019. Articles on the final list were filtered based on their titles and abstracts. The following information were recorded and analyzed with bibliometric method: article title, first author, year of publication, journal of publication, total number of citations, country, institution, and study topic.

The citation count for final articles on the list ranged from 71 to 2162, with a mean number of 207.7. The journal Spine contributed the maximum number of articles (37), followed by European Spine Journal (9) and Pain Physician (8). There were collectively 80 first authors contributing to articles on the final list. Twelve authors were represented multiple times in the top 100 articles. The most prolific years were 2008 and 2009, each had 11 articles published. With regard to country and region of origin, most articles were from the United States (58). The most cited article was published in Spine in 2000 by Fairbank and Pynsent, who discussed the role of the Oswestry Disability Index as an evaluation standard in spinal disorders, including LSS.

The current study analyzed the 100 most cited articles on LSS. It no doubt developed a useful resource with detailed information for many, particularly orthopedic and neurosurgery physicians who want to assimilate research focus and advance of LSS within a relatively short period. Researchers may benefit from emphasis on citation count while citing and evaluating articles and realize the deficiencies when high-level articles appear.

Retrospective study.

To describe the MRI findings of RNRs in patients with low back pain, and observe the imaging findings and the clinical outcome post decompression surgery.

The lumbar spine MRI of 202 patients (122 females) with proven RNRs were retrospectively reviewed. The morphology and the location of the RNRs in relation to the level of stenosis were described. The level(s), grade and cause of lumbar canal stenosis were recorded. The persistence of symptoms and the imaging findings on follow up post decompression surgery were recorded. The imaging findings were correlated among each other and with patients’ demographics.

Two distinctive morphological appearance of the RNRs were noted: loop (56.4%), and serpentine-shaped. In the majority of the cases the RNRs were located above the level of stenosis (79.7%). Eighteen patients underwent decompression surgery, only 4 patients remained symptomatic post decompression surgery. The RNRs changed in shape and location after decompression surgery. Age was a strong predictor value in the location of the RNRs. There was no correlation between the shape and location of the RNRs, or with the gender of the patients.

RNRs is not an uncommon finding on lumbar spine MRI with lumbar canal stenosis. Its importance remains a controversy. A common language between the radiologists and the clinicians is mandatory to aid in the management planning.

Retrospective cohort study.

Nonunion after posterior lumbar interbody fusion (PLIF) is associated with poor improvements in health-related quality of life (HRQOL). We aimed to investigate the influence of early osseous union after PLIF on HRQOL.

We reviewed 138 patients with 1-level PLIF (mean age 67 years, follow-up period ≥1 year). Postoperative lumbar computed tomography was performed to assess screw loosening and intervertebral union. HRQOL was assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire.

Thirty-nine patients (28%) showed complete union at 6 months postoperatively (early union group). Twenty-eight patients (20%) showed complete union at 6 to 12 months postoperatively (delayed union group), while 71 patients demonstrated noncomplete union. Effective improvement of lumbar spine dysfunction and psychological disorders was achieved in 19 (63.3%) and 17 (50.0%) patients in the early union group, in 9 (42.9%) and 14 (53.8%) patients in the delayed union group, and in 22 (34.9%) and 19 (29.2%) patients in the nonunion group, respectively (P = .036 and P = .036, respectively). The nonunion group had a significantly higher proportion of cases with screw loosening at 6 and 12 months postoperatively than the complete union group (P = .033 and P = .022).

Lumbar spine dysfunction and psychological disorders improved in cases with early complete union compared to those with nonunion. Screw loosening occurred in cases with nonunion predominantly from 6 months postoperatively. Therefore, the achievement of early complete union might be helpful for better HRQOL and lower incidence of postoperative complications.

Retrospective chart review with matched control.

To evaluate the indications and complications of spine surgery on super obese patients.

A retrospective review assessed super obese patients undergoing spine surgery at a level-1 trauma and spine referral center from 2012 to 2016. Outcomes were compared to age-matched controls with body mass index (BMI) <50 kg/m². The control group was further subdivided into patients with BMI <30 kg/m² (normal) and BMI between 30 and 50 kg/m² (obese).

Sixty-three super obese patients undergoing 86 surgeries were identified. Sixty patients (78 surgeries) were in the control group. Age and number of elective versus nonelective cases were not significantly different. Mean BMI of the super obese group was 55 kg/m² (range 50-77 kg/m²) versus 29 kg/m² in the controls (range 20-49 kg/m²). Fifty-two percent of surgeries were elective, and the most common indication was degenerative disease (39%). Compared with controls, super obese patients had a higher complication rate (30% [n = 19] vs 10% [N = 6], P = .0055) but similar 30-day mortality rate (5% vs 5%), a finding that was upheld when comparing super obese with each of the control group stratifications (BMI 30-50 and BMI <30 kg/m²). The most common complication among super obese patients was wound dehiscence/infection (n = 8, 13%); 2 patients’ surgeries were aborted. Complication rates for elective surgery were 21% (n = 7) for super obese patients and 4% (n = 1) for controls (P = .121); complication rates for nonelective procedures were 40% (n = 12) and 14% (n = 5), respectively (P = .023).

The complication rate of spine surgery in super obese patients (BMI ≥ 50 kg/m²) is significantly higher than other patients, particularly for nonelective cases.

Retrospective review.

Identify surgical complex adult spine deformity patients who are at increased risk for an unplanned postoperative 90-day readmission and/or reoperation.

A total of 227 consecutive records of complex adult (≥18 years old) spine deformity surgeries from 2015 to 2018 were reviewed. Demographics, comorbidities, operative details, and postoperative complication data was collected. Chi-square/Fisher’s exact test and t tests were used for bivariate analysis. To determine independent predictors for readmissions/reoperations, stepwise multivariate logistic regressions were employed. The C-statistic and Hosmer-Lemeshow (HL) value was used to measure concordance and goodness of fit.

Average age was 50.5 ± 17.8 years and 67.8% were female. Ninety-day readmission and reoperation rates were 7.0% and 5.3%, respectively. Median number of days after index discharge date resulting in readmission and reoperation were 16.5 and 28, respectively. The multivariate regression for 90-day readmissions included pulmonary comorbidity, depression, history of deep vein thrombosis/pulmonary embolism (DVT/PE), and gastrointestinal comorbidity (C-statistic = 0.82; HL = 0.79). Pulmonary comorbidity, depression, and history of DVT/PE increased risk for 90-day readmission by 5-, 3.5-, and 10.2-fold, respectively. The multivariate regression for 90-day reoperations was similar to readmissions (C-statistic = 0.89; HL = 0.31). Operative time>7 hours and history of DVT/PE increased risk for early reoperation by 5.8- and 8.7-fold, respectively.

An emphasis on medically optimizing patients with preexisting pulmonary comorbidities, depression, and history of DVT/PE may have a substantial impact on improving short-term outcomes in this population. The present study provides benchmark data and may serve as an initial model to predict unplanned reoperations and readmissions.

Retrospective cohort study.

Thoracolumbar 3-column osteotomy (3CO) is a powerful technique for correction of rigid adult spinal deformity (ASD). However, it can be associated with high-volume blood loss. This study seeks to investigate the efficacy and safety of tranexamic acid (TXA) in 3CO ASD patients.

ASD patients who underwent 3CO from 2006 to 2019 were retrospectively reviewed. Outcomes were compared between TXA and non-TXA patients, and TXA doses.

A total of 365 ASD patients were included: 181 TXA and 184 non-TXA. The mean age was 64.6 years and 60.5% were female. Operative time was shorter in the TXA group (295.6 vs 320.2 minutes, P < .001). However, TXA was not associated with shorter operative time (β = −6.5 minutes, 95% CI −29.0 to 15.9, P = .567) after accounting for surgeon experience. There was no difference in blood loss (2020.2 vs 1914.1 mL, P = .437) between groups. Overall complications (37.0% vs 33.2%, P = .439), including hypercoagulable (2.2% vs 3.8%, P = .373) and cardiac (13.3% vs 7.1%, P = .050) complications were similar between groups. TXA was not independently associated with blood loss or TXA-related complications. Both groups had comparable intensive care unit (2.5 vs 2.0 days, P = .060) and hospital (8.9 vs 8.2 days, P = .190) stays. There were no differences in outcomes between TXA dosing subgroups.

Systemic TXA use during 3CO for ASD surgery was not associated with decreased blood loss. TXA patients had shorter operative times, but this was driven mainly by surgeon experience on multivariate analysis. Routine use of TXA is safe and does not increase the incidence of hypercoagulable complications even at high doses.

Mixed-methods cross-sectional study.

Degenerative cervical myelopathy (DCM) is a common and disabling condition. While classically, assessment and diagnosis has focused on neuromuscular symptoms, many other disabilities have been linked. The aim of this study was to explore the consequences of DCM for those with lived experience, producing a long list to inform the development of a core outcome set for DCM research.

A 2-stage process was used: a focus group session of people with DCM (PwCM) and their supporters (n = 8) discussed the impact of DCM. This was used to develop a preliminary list of consequences, which were then placed into a survey of an online community of DCM sufferers (n = 224). Survey participants were asked to tick the consequences that they had experienced and given the opportunity to submit additional. Additional consequences were reviewed by a group of healthcare professionals and PwCM and included if not already represented. Demographic information including disease severity, age, and sex were captured for sampling comparison.

A total of 52 outcomes were identified from the focus group and nominally divided into 2 categories; symptoms (36 outcomes) and handicaps (18 outcomes), and further evaluated using a survey. All outcomes were recognized by at least 5% of respondents. A further 16 outcomes were added following the survey.

A list of DCM consequences has been defined from the perspective of PwCM. This will now be evaluated as part of AO Spine RECODE-DCM, an international multistakeholder collaboration to establish a core outcome set for research.

Retrospective database review.

The incidence and risk factors for surgical delay of multilevel spine fusion for adult spinal deformity (ASD), and the complications corresponding therewith, remain unknown. The objectives of this study are to assess the incidence and risk factors for unexpected delay of elective multilevel spinal fusions on the date of surgery as well as the postoperative complications associated with these delays.

We conducted a retrospective review of the ACS-NSQIP database on patients undergoing elective spinal instrumentation of greater than 7 levels for ASD between the years 2005 and 2015. Preoperative risk factors for delay and postoperative complications were compared between the cohorts of patients with and without surgical delays.

Multivariate analysis of 1570 (15.6%) patients identified advanced age, male sex, American Society of Anesthesiologists (ASA) Class 4, and history of smoking as independent risk factors for delay. Patients experiencing surgical delay demonstrated longer operative times, increased intraoperative bleeding, longer hospitalizations, and significantly higher rates of postoperative complications. Patients experiencing delay demonstrated an almost 7-fold increase in mortality rate (3.4% vs 0.5%, P < .001).

Delays in elective surgical care for spinal deformity are negatively related to patient outcomes. Advanced age, male sex, increased ASA class, and a history of smoking cigarettes place patients at risk for surgical delay of multilevel spinal fusion. Patients experiencing surgical delay are at higher risk for postoperative complications, including a 7-fold increase in mortality. These findings suggest that ASD surgery should be postponed in patients experiencing a delay, until modifiable risk factors can be medically optimized, and perhaps postponed indefinitely in those with nonmodifiable risk factors.

Retrospective cohort.

The objective of this study was to assess the effectiveness of the O-arm as an intraoperative imaging tool by comparing accuracy of pedicle screw placement to freehand technique.

The study comprised a total of 1161 screws placed within the cervical (n = 187) thoracic (n = 657), or lumbar (n = 317) spinal level. A pedicle breach was determined by any measurable displacement of the screw outside of the pedicle cortex in any plane on postoperative images. Each pedicle screw was subsequently classified by its placement relative to the targeted pedicle. Statistical analysis was then performed to determine the frequency and type of pedicle screw mispositioning that occurred using the O-arm versus freehand technique.

A total of 155 cases (O-arm 84, freehand 71) involved the placement of 454 pedicle screws in the O-arm group and 707 pedicle screws in the freehand group. A pedicle breach occurred in 89 (12.6%) screws in the freehand group and 55 (12.1%) in the O-arm group (P = .811). Spinal level operated upon did not influence pedicle screw accuracy between groups (P > .05). Three screws required revision surgery between the 2 groups (O-arm 1, freehand 2, P > .05). The most frequent breach type was a lateral pedicle breach (O-arm 22/454, 4.8%; freehand 54/707, 7.6%), without a significant difference between groups (P > .05).

The use of the O-arm coupled with navigation does not assure improved transpedicular screw placement accuracy when compared with the freehand technique.

Technical report.

Dural tear is one of the most common complications of endoscopic spine surgery. Although endoscopic dural repair of the durotomy area may be difficult, we successfully repaired the dural tear area using nonpenetrating clips during biportal endoscopic surgery. We introduce the surgical technique of dural repair using nonpenetrating titanium clips in biportal endoscopic spine surgery and report its clinical outcome.

We retrospectively reviewed and analyzed 5 patients who were treated via primary dural repair using nonpenetrating titanium clips during biportal endoscopic lumbar surgery. The 2 methods of dural clipping and repair include 2 or 3 portals. We analyzed radiological parameters such as cerebrospinal fluid collection as well as clinical parameters, including postoperative clinical outcomes.

Five patients underwent biportal endoscopic dural repair using nonpenetrating clips. Incidental durotomy was successfully repaired using nonpenetrating titanium clips in all 5 patients. No cerebrospinal fluid collection was detected in the postoperative magnetic resonance images. Clinically, preoperative symptoms improved significantly after surgery (P < .05).

We repaired the dural tear area completely using nonpenetrating titanium vascular anastomosis clips in biportal endoscopic lumbar surgery. Dural repair via clipping method may be an effective alternative for incidental durotomy.

Retrospective Cohort Study.

Spinal surgery site infection and chronic implant infection are possible causes for ongoing pain, implant loosening, and failed back surgery syndrome. Evidence of chronic infection was found in 29.1% of revision cases but is also found in a considerable number of degenerative cases without prior surgery. Infection mechanisms and possible clinical correlations are unclear.

Retrospective analysis of standardized surgery site screening (swab, tissue samples, implant sonication) in 181 cases without clinical evidence of preoperative surgery site infection.

Screening results of cases without prior spinal surgery (n = 49, 10.2% positive) were compared to cases with prior spine surgery without implant placement (e.g. micro discectomy) (n = 21, 23.8% positive), revision cases following singular spinal fusion (n = 73, 23.2% positive), and cases with multiple revisions (n = 38, 50.0% positive). Propionibacterium spp. detection rate increased to 80% in positive cases with multiple revisions. Implants in place during revision surgery had a significantly higher infection rate (32.4%) compared to no implant (14.2%, p = 0.007). Positive cases had a significantly higher pain level prior to surgery compared to negative cases (p = 0.019). Laboratory parameters had no predictive value. Logistic regression revealed that previous spinal surgeries (odds ratio [OR] 1.38 per operation, p < 0.001) and male sex (OR 1.15, p = 0.028) were independent predictive factors for infection.

Previous spinal surgery is a risk factor for chronic surgery site infection, leading to chronic pain, implant loosening, and revision. The presence of Propionibacterium spp. was correlated with chronic implant loosening and was more likely with cumulative surgeries.

Prospective cohort study.

Management of osteoporotic vertebral compression fracture (OVCF) remains an unsolved problem for a spine surgeon. We hypothesize that instability at the fracture site rather than neural compression is the main factor leading to a neurological deficit in patients with OVCF.

In this study, the prospective data of patients with osteoporotic fractures with incomplete neurological deficits from January 2015 to December 2017 was analyzed in those who underwent posterior instrumented fusion without neural decompression.

A total of 61 patients received posterior indirect decompression via ligamentotaxis and stabilization only. Of these 17 patients had polymethylmethacrylate (PMMA) augmented screws and in 44 patients no PMMA augmentation was done. The mean preoperative kyphosis was 27.12° ± 9.63°, there was an improvement of 13.5° ± 6.87° in the immediate postoperative period and at the final follow-up, kyphosis was 13.7° ± 7.29° with a loss of correction by 2.85° ± 3.7°. The height restoration at the final follow-up was 45.4% ± 18.29%. In all patients, back pain was relieved, and neurological improvement was obtained by at least 1 American Spinal Injury Association Impairment Scale in all except 3 patients.

We propose that neural decompression of the spinal cord is not always necessary for the treatment of neurological impairment in patients with osteoporotic vertebral collapse with dynamic mobility. Dynamic magnetic resonance imaging is a valuable tool to make an accurate diagnosis and determine precise surgical plan and improving the surgical strategy of OVCF.

A quality-control Internet-based study using recognized quality scoring systems.

The aim of the study is to evaluate the quality, content and readability of online information on kyphosis.

The 3 most frequently used search engines were identified and a search for “Kyphosis” was made in each. The 2 reviewers categorized their Web-sites by type, and the quality of each was assessed using well-known scoring systems, including the DISCERN score, JAMA benchmark, GQS, and the kyphosis specific content score. The Flesch-Kincaid grade level (FKGL) was used to assess the readability. The quality of the information was also evaluated according to the presence and absence of the HONcode.

Sixty unique Web sites were identified and analyzed. The distribution of the categories was 33 (55%) medical, 22 (36.7%) academic, 2 (3.3%) non-physician, 2 (3.3%) commercial and 1 (1.7%) physician. There wasn’t statistically significant difference between the sources in terms of DISCERN, JAMA, GQS and KSC scores (P > 0.05). However, a review of the FKGL scores revealed that the academic-based websites’ FKGL score was significantly higher than the medical-based websites (P: 0.007). Also there wasn’t statistically significant difference among the DISCERN, JAMA, GQS, KSC, FKRS and FKGL scores of the web-sites according to the HON code’s presence (P > 0.05).

Information about kyphosis on the Internet is of limited quality and low information value. The readability of the online information in our results showed a significantly higher reading level than the sixth grade level recommended by the AMA and NIH.

Meta-analysis.

To compare outcomes between minimally invasive scoliosis surgery (MISS) and traditional posterior instrumentation and fusion in the correction of adolescent idiopathic scoliosis (AIS).

A literature search was performed using MEDLINE, PubMed, EMBASE, Google scholar and Cochrane databases, including studies reporting outcomes for both MISS and open correction of AIS. Study details, demographics, and outcomes, including curve correction, estimated blood loss (EBL), operative time, postoperative pain, length of stay (LOS), and complications, were collected and analyzed.

A total of 4 studies met the selection criteria and were included in the analysis, totaling 107 patients (42 MIS and 65 open) with a mean age of 16 years. Overall there was no difference in curve correction between MISS (73.2%) and open (76.7%) cohorts. EBL was significantly lower in the MISS (271 ml) compared to the open (527 ml) group, but operative time was significantly longer (380 min for MISS versus 302 min for open). There were no significant differences between the approaches in pain, LOS, complications, or reoperations.

MISS was associated with less blood loss but longer operative times compared to traditional open fusion for AIS. There was no difference in curve correction, postoperative pain, LOS, or complications/reoperations. While MISS has emerged as a feasible option for the surgical management of AIS, further research is warranted to compare these 2 approaches.

Network meta-analysis of randomized controlled trials.

Lumbar spondylolisthesis is a common indication for spinal fusion. Lumbar interbody fusion (LIF) is popular method to achieve arthrodesis, but previous syntheses usually used head-to-head comparison of 2 surgical methods, and no of them pooled analysis with high-quality. This network meta-analysis of randomized controlled trials was carried out to simultaneously compare fusion techniques in the treatment of lumbar spondylolisthesis.

Three databases were searched for randomized controlled trials (RCTs) on this topic. After critical appraisal, fusion rate, overall adverse events, operative time, Oswestry Disability Index, and pain were extracted for analysis. We conduced network meta-analysis using contrast-based method. Primary outcomes were reported as risk ratio (RR) with 95% confidence interval (CI).

Fifteen RCTs (n = 992) met our eligibility criteria. The RCTs treated patients posterolateral fusion (PLF), posterior LIF (PLIF), transforaminal LIF (TLIF), minimally invasive (MIS) TLIF, extreme lateral LIF (XLIF), and circumferential fusion. The pooled estimate showed that circumferential fusion led to significantly higher fusion rate than PLF (RR = 2.15, 95%CI:1.41–3.28), PLIF (RR = 2.11, 95%CI:1.38–3.22), TLIF (RR = 2.13, 95%CI:1.39–3.27), MIS-TLIF (RR = 2.13, 95%CI:1.35–3.35), and XLIF (RR = 2.01, 95%CI: 1.25–3.22). Moreover, circumferential fusion exhibited the best balance in probability between fusion rate and adverse event rate. No evidence showed inconsistency or small-study effect in the results.

Collectively, circumferential fusion might be worth to be recommended because it exhibits the best balance between fusion rate and overall adverse event. PLF is still an inferior procedure and requires shorter operative time.

Systematic review and meta-analysis.

We performed this meta-analysis to evaluate whether intradiscal Platelet Rich Plasma(PRP) injection has any beneficial role in the management of lumbar disc disease.

We conducted independent and duplicate electronic database searches including PubMed, Embase, and Cochrane Library till September 2020 for studies investigating the role of intradiscal PRP in the management of lumbar disc disease. The analysis was performed in the R platform using OpenMeta[Analyst] software.

13 studies including 2 RCTs, 5 prospective, and 6 retrospective studies involving 319 patients were included in the meta-analysis. A single-arm meta-analysis of the included studies showed a beneficial effect of the intervention in terms of pain relief outcomes like VAS score (p < 0.001), pain component of SF-36 (p = 0.003) while such improvement was not seen in functional outcome measures like ODI score (p = 0.071), the physical component of SF-36 (p = 0.130) with significant heterogeneity noted among the included studies. No structural improvement in magnetic resonance imaging was observed (p = 0.106). No additional procedure-related adverse events were noted in the included studies (p = 0.662).

There is a paucity of high-quality studies to give conclusive evidence on the benefits of intradiscal PRP for lumbar disc disease. Although intradiscal PRP injection has shown some beneficial effect in controlling pain for lumbar disc disease, we could not find structural or functional improvement from the included studies. Hence, we recommend large double-blind double-arm randomized controlled studies to analyze the benefits of the intervention being analyzed.

Meta-analysis.

To systematically compare the effectiveness and safety of vertebral augmentation procedure (VAP) with non-surgical management (NSM) for the treatment of osteoporotic vertebrate compression fractures (OVCFs).

Systematic reviews and meta-analyses with the comparison between VAP and NSM were identified to extract randomized controlled trials from electronic database. Additionally, recently published RCTs were identified. Two researchers independently extracted the data. The primary outcome of this meta-analysis was pain relief evaluated by visual analogue scale (VAS).

Twenty RCTs involving 2566 patients with painful OVCFs were included. Significant differences were found between percutaneous vertebroplasty (PVP) and conservative treatment (CT) in VAS at each time point during follow-up period. The differences of VAS were not significant between PVP and sham procedure at most time points during follow-up period. In subgroup analysis based on fracture type and fracture location, significant differences of VAS were found between PVP and CT and were not found between PVP and sham procedure. In subgroup analysis of duration of back pain, significant differences were found between PVP and CT in VAS at 1 week, 3 month and 1 year. And the differences of VAS were not significant between PVP and CT at 1 month and 6 month.

BKP is considered sufficient to achieve good clinical outcomes. PVP is associated with on beneficial effect on treatment of painful OVCFs compared with sham procedure. The indication and timing of VAP need further research. More independently high-quality RCTs with sufficiently large sample sizes reporting cost-effectiveness are needed.

Systemic review and meta-analysis.

To review and establish the effect of tobacco smoking on risk of nonunion following spinal fusion.

A systematic search of Medline, Embase, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from inception to December 31, 2020, was conducted. Cohort studies directly comparing smokers with nonsmokers that provided the number of nonunions and fused segments were included. Following data extraction, the risk of bias was assessed using the Quality in Prognosis Studies Tool, and the strength of evidence for nonunion was evaluated using the GRADE working group criteria. All data analysis was performed in Review Manager 5, and a random effects model was used.

Twenty studies assessing 3009 participants, which included 1117 (37%) smokers, met inclusion criteria. Pooled analysis found that smoking was associated with increased risk of nonunion compared to not smoking ≥1 year following spine surgery (RR 1.91, 95% CI 1.56 to 2.35). Smoking was significantly associated with increased nonunion in those receiving either allograft (RR 1.39, 95% CI 1.12 to 1.73) or autograft (RR 2.04, 95% CI 1.54 to 2.72). Both multilevel and single level fusions carried increased risk of nonunion in smokers (RR 2.30, 95% CI 1.64 to 3.23; RR 1.79, 95% CI 1.12 to 2.86, respectively).

Smoking status carried a global risk of nonunion for spinal fusion procedures regardless of follow-up time, location, number of segments fused, or grafting material. Further comparative studies with robust methodology are necessary to establish treatment guidelines tailored to smokers.