Global Spine Journal

Multicenter observational survey study.

To quantify and compare the inter- and intraobserver reliability of Allen-Fergusson (A-F), Harris, Argenson, and AOSpine (AOS) classifications for cervical spine injuries, in a multicentric survey of neurosurgeons with different levels of experience.

We used data of 64 consecutive patients. Totally, 37 surgeons (from 7 centers), were included in the study. The initial assessment was returned by 36 raters. The second assessment performed after 1.5 months included 24 raters.

We received 15 111 answers for 3840 evaluations. Raters reached a fair general agreement of the A-F scale, while the experienced group achieved κ = 0.39. While all groups showed moderate interrater reliability for primary assessment of Harris scale (κ = 0.44), the κ value for experts decreased from 0.58 to 0.49. The Argenson scale demonstrated moderate and substantial agreement among all raters (κ = 0.47 and κ = 0.55, respectively). The AOS scheme primary assessment general kappa value for all types of injuries and across all raters was 0.49, reaching substantial agreement among experts (κ = 0.62) with moderate agreement across beginner and intermediate groups (κ = 0.48 and κ = 0.44, respectively). The second assessment general agreement kappa value reached 0.56.

We found the highest values of interobserver agreement and reproducibility among surgeons with different levels of experience with Argenson and AOSpine classifications. The AOSpine scale additionally incorporated more detailed description of compression injuries and facet-joint fractures. Agreement levels reached for Allen-Fergusson and Harris scales were fair and moderate, respectively, indicating difficulty of their application in clinical practice, especially by junior specialists.

Retrospective cohort study.

Violation of the posterior soft tissues is believed to contribute to the development of proximal junctional kyphosis (PJK). Biomechanical and clinical studies suggest that augmentation of the posterior ligamentous structures (PLS) may help prevent PJK. The purpose of this study was to evaluate the effect of PLS augmentation on the rate of PJK at 1 year.

A retrospective single-surgeon cohort study was performed of 108 adult spinal deformity patients who underwent 5 level fusions to the pelvis. Patients were divided into 2 groups: PLS+ patients had reconstruction of the PLS between upper instrumented vertebrae +1 (UIV+1) and UIV−1 with a surgical nylon tape while PLS− patients did not. Demographics, surgical data, and sagittal alignment parameters were compared between the cohorts. The primary outcome of interest was the development of PJK at final follow-up. A subgroup propensity match and logistic regression model were utilized to control for differences in the cohorts.

A total of 108 patients met final criteria, 31 patients (28.7%) were PLS+. There were no differences with regard to preoperative or final sagittal alignment parameters, number of levels fused, rates of 3-column osteotomies, and body mass index (P > .05), though the PLS+ cohort was older and had larger initial sagittal corrections (P < .05). The rates of PJK for PLS+ (27.3%) and PLS− (28.6%) were similar (P = .827). After controlling for sagittal correction via propensity matching, PLS+ had no impact on PJK (29% vs 38.7%, P = .367). In our multivariate analysis, only increased sagittal malalignment and failure to restore sagittal balance were retained as significant predictors of PJK.

Even after controlling for extent of correction and preoperative sagittal alignment, PLS reinforcement at UIV+1 using a hand-tensioned nylon tape does not reduce the incidence of PJK at 1 year.

A retrospective cohort study.

Although it is controversial whether to choose only discectomy or fusion surgery in patients with disc herniation and spondylolysis, we expected that aggravation of the spondylolysis may be prevented if posterior supporting muscles can be well-preserved without extensive exploration. The purpose of this study was to investigate the influence of L5 spondylolysis on surgical outcomes following microendoscopic discectomy (MED) in patients with concomitant lumbar disc herniation and spondylolysis.

We reviewed 811 patients who underwent MED for L4/5 or L5/S1 disc herniation. Patients with spondylolisthesis were excluded. We compared surgical outcomes of patients with and without L5 spondylolysis, whose age, sex, and surgical level were matched.

A total of 655 patients (80.7%) with complete data were considered eligible for the study. MED was performed at L4/5 and L5/S1 in 338 and 317 patients, respectively. A total of 20 patients (3.1%) had concomitant L5 spondylolysis and disc herniation at L4/5 (9 patients) or L5S1 (11 patients). As we compared each outcome of the 20 patients having L5 spondylolysis with 40 matched patients without L5 spondylosis, there were no significant differences in preoperative or postoperative outcomes between the 2 groups, and no patient with spondylolysis had undergone additional surgery during the mean follow-up period of 24 months.

MED demonstrated good surgical results regardless of the presence or absence of spondylolysis. In patients with sciatica with concomitant disc herniation and spondylolysis, but without spondylolisthesis, fusion surgery may not be always necessary.

Retrospective observational study.

Thoracic disc prolapse (TDP) surgeries have reported complications ranging from paraplegia to approach related complications. This study is to present a series of TDP patients surgically treated with transforaminal thoracic interbody fusion (TTIF). Emphasis on surgical technique and strategies to avoid complications are analyzed.

Eighteen patients with TDP were included. Imagings were analyzed for end-plate changes and calcification. Type of disc prolapse (central/para-central) and percentage of canal occupancy were noted. Objective outcome was quantified with Visual Analogue Scale (VAS), modified Nurick’s grade, and ASIA (American Spinal Injury Association) score. All complications were noted.

Eighteen patients (average age 43.65 years) having total 22 levels operated, that included double level (n = 2) and missed level (n = 2) are reported. All patients had myelopathy. Calcification of disc (n = 13), central disc prolapses (n = 9), para-central (n = 11) and more than 50% canal occupancy (n = 8) were noted. VAS back pain, modified Nurick’s grade and ASIA grade improved significantly in all patients. One patient had postoperative transient deficit. The functional score achieved its maximum at 1 year follow-up and remained static at final follow-up of 65.05 months. Union was achieved in all patients.

The most important factor for outcome in TDP is the technical aspect of avoiding cord manhandling and avoiding wrong level surgeries. TTIF is not devoid of complications but can give good results to posterior approach trained surgeons.

Retrospective observational study.

To analyze the clinical and radiological outcomes of lower limb fractures following surgical treatment in patients with chronic spinal cord injury (SCI).

Between January 2003 and December 2015, 102 chronic SCI patients with a lower limb fracture were surgically treated at our hospital. A total of 58 patients met the inclusion criteria and were recruited for final analysis. Patients with 2-stage procedure or incomplete clinical records with lost-to-follow-up were excluded from the study. Patients were divided into 2 groups (group 1= internal fixation; group 2 = external fixation). Primary outcome measures were to identify the number of nonunions via Kaplan-Meier analysis and the time to bone consolidation. The diagnosis of a pseudarthrosis was made after more than 180 days of consolidation time. Considering the Kaplan-Meier analysis, pseudarthrosis was interpreted as treatment failure. Secondary outcome measure was to evaluate the complication rate with special focus on heterotopic ossification.

A total of 58 chronic SCI patients with closed bone fractures were included in this study. Fifty-two fractures (88%) were simple and 7 (12%) were complex (type C) fractures according to AO classification. The majority of patients (34 cases, 59%) developed femur fractures followed by 24 tibial fractures (41%). Seventeen patients received an external (29%) and 41 an internal fixation (71%). Bone consolidation was reported in 31 patients (53%) with a mean time interval of bone consolidation after 97 days (range from 45 to 160 days; SD = 30). The reported nonunion (pseudarthrosis) rate was 47%. Comparing the internal group (n = 15 patients) versus the external group (n = 14), we could not find any significant difference (P = .939) concerning the bone consolidation time. The Kaplan-Meier analysis showed a 75% cumulative survivorship at 120 days (internal group) versus 111 days (external group). Most common postoperative complications occurred in the internal fixation group with Wound infections being predominantly observed (10%), followed by heterotopic ossifications (8%).

Our results show that surgical treatment of lower limb fractures in chronic SCI patients is a challenging treatment with a high pseudarthrosis rate in both groups. The complication rate seems to be lower in the patients treated with external fixation. As a clinical recommendation, longer implants should be used for a stable osteosynthesis since SCI patients seem to have a higher load on the osteosynthesis material due to missing sensomotoric feedback.

Retrospective cohort study and systematic review.

Endoscopic decompression offers a minimally invasive alternative to traditional, open laminectomy. However, comparison of these surgical techniques has been largely limited to small, single-center studies. In this study, we perform the first international, multicenter comparison of both with regard to their associated rates of mortality, complications, readmissions, and reoperations.

The 2017 American College of Surgeons’ National Surgical Quality Improvement Program (ACS-NSQIP) database, containing data from over 650 hospitals internationally, was queried to evaluate the effect of endoscopic guidance on adverse events. Operative time, length of stay, readmission and reoperation rates, as well as the incidence of peri- and postoperative complications, were compared between endoscopic and open groups. The PubMed/MEDLINE database was queried for studies comparing the techniques.

A total of 10 726 single-level lumbar decompression patients were identified and included in this study, 34 (0.32%) of whom were operated upon endoscopically. Apart from 2 (5.88%) readmissions, among which only 1 was unplanned, there were no reported surgical complications within the endoscopic group. The mean length of stay for these patients was 0.86 ± 1.44 days, with procedures lasting an average of 91.89 ± 46.72 minutes. However, these endpoints did not differ significantly from the open group. On literature review, 16 studies met the inclusion criteria, and largely consisted of single-center, retrospective analyses.

Endoscopically guided approaches to single-level lumbar decompression did not reduce the incidence of adverse events, length of stay or operative time, perhaps due to advances among certain nonendoscopic techniques, such as microsurgery.

Retrospective analysis. Level of evidence III.

To describe the results after a minimum 1-year follow-up in patients treated with percutaneous discoplasty (PD), a minimally invasive technique to treat low back pain in elderly patients with advanced degenerative disc disease. The procedure consists in improving stability by injecting bone cement in a severely degenerated pneumodisc. There are few reports in the literature about this technique.

Fifty-four patients with advanced disc disease with/without degenerative scoliosis treated with PD with at least 1 year follow-up were studied, variables included clinical (visual analogue scale [VAS] and Owestry Disability Index [ODI]) and radiological parameters (lumbar lordosis and Cobb angle), as well as hospital length of stay and complications.

At 1-year postoperation, significant pain reduction (VAS: preoperative 7.8 ± 0.90; postoperative 4.4 ± 2.18) and improvement in the ODI (preoperative 62 ± 7.12; postoperative 36.2 ± 15.47) were observed with partial correction of radiological parameters (5° mean increase in lumbar lordosis and decrease in Cobb angle). Mean surgical time was 38 minutes, and the mean length of hospital stay was 1.2 days.

PD, currently not a very well-known technique, appears to be—at least in the short-term follow-up—an effective treatment option in selected cases with low back pain due to advanced degenerative disc disease.

Retrospective study.

To evaluate the demographics, prevalence, etiology, severity, and outcomes of spinal cord injuries (SCIs) resulting from ischemic infarction.

All patients with SCI and a diagnosis of cord infarct who were admitted to the inpatient rehabilitation unit at a level 1 trauma center from January 2003 to January 2014 were identified using an administrative billing database. Outcomes measures were evaluated.

Among 685 unique SCI patients who were identified, 30 (4.4%) had SCI due to spinal ischemic infarction. The mean age was 59 years (range 17-80 years). Fifty percent of patients had ASIA (American Spinal Injury Association) A and B severity. Most common causes were the following: 6 (20%) abdominal aortic aneurysm (AAA) repairs, 6 (20%) arteriovenous fistulas, and 6 (20%) with an unknown cause. Surgical complications led to 4 (13.3%) cord infarcts and was associated with a higher severity of injury (P = .02) compared with other etiologies. Other causes included systemic hypotension, AAA rupture, trauma, diabetic ketoacidosis, and after radiation therapy. At follow-up, 6 (20%) of patients were able to ambulate normally without assistance, 7 (23.3%) were ambulating with assistance, and 17 (56.7%) were still wheelchair bound. Clinical improvement in ambulatory status was noted in 6 (20%) patients and was associated with less severe initial injury (P = .02).

While the existing literature associates spinal cord infarction with aortic pathologies and surgery, these caused less than 30% of cases, while nonaortic surgical complications were associated with the most severe injuries. Outcomes were worse than previously reported in the literature.

Retrospective radiographic investigation.

To evaluate the long-term radiographic and functional outcomes of patients in whom there is absence of radiographic union at 2 years after single-level anterior cervical discectomy and fusion (ACDF).

Thirty-one patients were evaluated at standard postoperative time intervals per index trial protocol. Plain film radiographic fusion criteria at the arthrodesis level was defined as interspinous motion (ISM) <1 mm with corresponding motion at a non-arthrodesed superjacent level ISM ≥4 mm. Radiographs and functional outcome measures were acquired at each follow-up visit. Delayed union was defined as lack of radiographic union by 24 months.

Nine patients demonstrated radiographic evidence of delayed radiographic union at 24 months. Of those 9 patients, 5 patients demonstrated evidence of union during the follow-up period to 72 months. Despite the absence of radiographic union based on our criteria, 3 of the 4 remaining patients reported remarkable improvements in pain scores and functional outcomes.

The natural history of delayed union at 24 months after ACDF was still favorable despite the prolonged delay in union. The majority of patients (5 of 9) without radiographic union at 24 months did proceed to radiographic union by final follow-up. In addition, patients that did not meet our criteria for fusion maintained postoperative improvements in patient-reported outcome scores. In summary, our study patients undergoing a single-level ACDF with asymptomatic radiographic delayed union at 24 months can expect maintained improvements in postoperative patient-reported outcomes scores and can still progress to successful radiographic fusion.

Retrospective cohort study.

The objective of this study was to determine whether lower socioeconomic status was associated with increased resource utilization following anterior discectomy and fusion (ACDF).

The National Inpatient Sample database was queried for patients who underwent a primary, 1- to 2-level ACDF between 2005 and 2014. Trauma, malignancy, infection, and revision surgery were excluded. The top and bottom income quartiles were compared. Demographics, medical comorbidities, length of stay, complications, and hospital cost were compared between patients of top and bottom income quartiles.

A total of 69 844 cases were included. The bottom income quartile had a similar mean hospital stay (2.04 vs 1.77 days, P = .412), more complications (2.45% vs 1.77%, P < .001), and a higher mortality rate (0.18% vs 0.11%, P = .016). Multivariate analysis revealed bottom income quartile was an independent risk factor for complications (odds ratio = 1.135, confidence interval = 1.02-1.26). Interestingly, the bottom income quartile experienced lower mean hospital costs ($17 041 vs $17 958, P < .001).

Patients in the lowest income group experienced more complications even after adjusting for comorbidities. Therefore, risk adjustment models, including socioeconomic status, may be necessary to avoid potential problems with access to orthopedic spine care for this patient population.

Retrospective cohort study.

To determine whether there is an association between insurance status and curve magnitude in idiopathic scoliosis pediatric patients in mainland China.

Medical records of patients with adolescent idiopathic scoliosis in 4 tertiary spine centers across China from January 2013 to December 2017 were analyzed. Data was extracted on insurance status, curve magnitude, recommended treatment at presentation, source of referral, and treatment initiated. Additional information was collected for patients requiring corrective surgery, including time from recommendation for surgery to surgery and clinically relevant parameters such as, postoperative complications, and pre-/postoperative Scoliosis Research Society–22 scores were also collected for patients requiring corrective surgery.

Of the 1785 patients included, 1032 were Urban Resident Basic Medical Insurance Scheme (URBMS) insured and 753 were New Rural Cooperative Medical Scheme (NRCMS) insured. NRCMS patients presented with a larger major curve than URBMS patients (32.9° ± 15.1° vs 29.3° ± 12.6°, P = .028). For patients having surgery recommended, NRCMS patients presented with a larger mean Cobb angle at the first presentation (57.7° vs 50.9°, P < .0001) and at time of surgery (61.3° vs 52.2°, P < .0001), and experienced a significantly longer time from surgery recommendation to decision for surgery. Complication rates were comparable between the 2 groups, except for pulmonary complications (NRCMS 7.3% vs URBMS 2.8%, P = .04). Postoperatively, patients covered by NRCMS insurance experienced greater overall improvement in health-related quality of life and were less satisfied with the treatments.

This study shows that health insurance may influence the severity of scoliosis on presentation, with implications on early diagnosis and surgery time.

Retrospective cohort study.

The aim of this study was to compare the results of cervical laminectomy (CL) performed with ultrasonic bone scalpel (UBS) or conventional method (CM).

This study comprised 311 CL performed by a single surgeon between January 2004 and December 2017. Group A (GpA) comprised 124 cases of CL performed using UBS, while Group B (GpB) comprised 187 cases of CL performed using CM. These 2 groups were compared in terms of demographic characteristics of patients, duration of surgery, estimated blood loss, and surgical complications.

GpA included 112 males and 12 females, mean age being 61.18 years. GpB comprised 166 males and 21 females, mean age being 62.04 years. Mean duration of surgery, estimated blood loss, and length of hospital stay was 65.52/70.87 minutes, 90.24/98.40 mL, and 4.80/4.87 days in GpA and GpB, respectively. Six patients were reported to have dural injuries in each group. In GpA, 2 cases of C5 palsy and 1 nerve root injury was observed, while in GpB, 3 cases of C5 palsy and no nerve root injury was reported. One patient had developed transient neurological deterioration postsurgery in GpA as against 11 patients in GpB.

Neurological complications observed in CM leads to intensive care unit admission, additional morbidity, and additional expenditure, whereas UBS provides a safe, rapid, and effective means of performing CL, thereby decreasing the rate of surgical complications and postoperative morbidity.

Narrative review.

To provide an overview on the diagnosis and surgical management of rheumatoid involvement of the lumbar spine. Rheumatoid arthritis (RA) is a chronic inflammatory disease of synovial joints, most commonly appendicular followed by axial. Although cervical spine involvement of RA is well documented, data on lumbar spine involvement and surgical management remains limited.

Using PubMed, studies published prior to November 2018 with the keywords “RA, etiology”; “RA, spine management”; “RA, surgical management”; “RA, treatment”; “RA, DMARDs”; “RA, lumbar spine”; “RA, spine surgical outcomes”; “RA, imaging” were evaluated.

The narrative review addresses the epidemiology, manifestations, imaging, surgical complications, and operative and nonoperative management of RA involvement of the lumbar spine.

Rheumatoid involvement of the lumbar spine can present with lower back pain, neurogenic claudication, radiculopathy, spinal deformity, and instability. Patients with RA have significantly higher rates of vertebral fractures and complications following surgical intervention. However, in the setting of instability and spinal deformity, thoughtful surgical planning in conjunction with optimal medical management is recommended.

Systematic literature review.

Our primary objective was to compare reported fusion rates after anterior cervical discectomy and fusion (ACDF) using structural allograft versus polyetheretherketone (PEEK) interbody devices in patients with cervical spine degeneration. Our secondary objectives were to compare differences in rates of subsidence and reoperation and in patient-reported outcomes between the 2 groups.

Through a systematic review of the English-language literature using various databases, we identified 4702 articles. After we applied inclusion and exclusion criteria, 14 articles (7 randomized controlled trials, 4 prospective studies, and 3 retrospective studies) reporting fusion rates of structural allograft or PEEK interbody devices were eligible for our analysis. No randomized controlled trials compared outcomes of structural allograft versus PEEK interbody devices. Extracted data included authors, study years, study designs, sample sizes, patient ages, duration of follow-up, types of interbody devices used, fusion rates, definition of fusion, reoperation rates, subsidence rates, and patient-reported outcomes.

Fusion rates were 82% to 100% for allograft and 88% to 98% for PEEK interbody devices. The reported data were insufficient to perform meta-analysis. Structural allograft had the highest reported rate of reoperation (14%), and PEEK interbody devices had the highest reported subsidence rate (18%). Patient-reported outcomes improved in both groups. There was insufficient high-quality evidence to compare the associations of various PEEK modifications with fusion rates.

Fusion rates were similar between structural allograft and PEEK interbody devices when used for ACDF for cervical spine degeneration. Currently, there is insufficient high-quality evidence to assess associations of PEEK modifications with fusion rates.

II.

Meta-analysis of randomized controlled trials (RCTs).

The aim was to analyze the efficacy of zoledronic acid (ZA) versus denosumab in the prevention of spinal cord compression in patients with spine metastases from advanced cancers, by evaluating all available RCTs on this subject.

A systematic search of electronic databases (PubMed and MEDLINE) was performed to identify all published RCTs comparing ZA with denosumab in prevention of spinal cord compressions in spine metastases. Risk of bias of the studies was assessed. The primary outcomes evaluated were spinal cord compression.

Three RCTs (5274 patients) were included. Denosumab was not significantly superior to ZA in reducing the likelihood of spinal cord compression, when all tumor types were combined (odds ratio [OR] 0.92, 95% confidence interval [CI; 0.66, 1.28], P = .66). Denosumab was not significantly favored over ZA in endodermal origin (breast and prostate; OR 0.72, 95% CI [0.43, 1.19], P = .20) and mesodermal origin tumors (solid tumors and multiple myeloma; OR 1.10, 95% CI [0.72, 1.69], P = .66).

Denosumab does not significantly reduce the likelihood of spinal cord compressions in comparison to ZA in patients with spine metastases. When spinal cord compressions were grouped by tumor origin (endodermal or mesodermal), there remained no significant difference between denosumab and ZA. Further long-term studies are needed to determine the effectiveness of these treatment regimens.

A systematic review and meta-analysis.

The results from previous meta-analyses are limited by the small number of included studies. Moreover, the risk factors of heterotopic ossification (HO) have not been well studied. Therefore, this study aims to estimate the prevalence of HO after cervical total disc replacement (CTDR) at different follow-up time points and explore potential risk factors for HO.

We searched databases to identify eligible studies that reported the rate of HO after CTDR. The pooled prevalence of HO, according to different grades of HO, length of follow-up and types of prosthesis, and 95% confidence intervals (CIs) were calculated. Multivariable meta-regression analyses were performed to identify factors that may contribute to the heterogeneity between estimates.

Of the 94 studies included, 82 studies reported an overall rate of HO, encompassing a total of 5861 cervical spinal levels that underwent CTDR. The overall pooled prevalence of HO was 32.5% (95% CI 26.7% to 38.4%). Single-level CTDR was associated with a higher overall rate of HO. When the rate of HO was stratified by McAfee/Mehren classification, the pooled prevalence of range of motion (ROM)–limiting HO was 11.0% (95% CI 9.2% to 12.8%). Latest publication, single-level CTDR, longer follow-up period, and studies published outside were associated with a higher rate of ROM-limiting HO.

We provide a comprehensive overview of the prevalence of different grades of HO. This meta-analysis also identifies and rules out some risk factors for HO after CTDR.