Global Spine Journal

Retrospective study.

To determine rates of medical and surgical postoperative complications in adults with hypoalbuminemia undergoing anterior lumbar interbody fusion (ALIF).

This was a retrospective analysis of prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database of patients (≥18 years old) undergoing ALIF procedures, identified by CPT (Current Procedural Terminology) code from 2011 to 2014. Poor nutritional status was defined by a preoperative serum albumin level <3.5 g/dL, and albumin levels above this were considered normal. Multivariate logistic regression models were utilized to assess preoperative risk factors including nutritional status as predictors of specific postoperative complications. Significance was defined as P < .05 and odds ratios (ORs) were calculated with a 95% confidence interval (CI). This model was used to determine the strength of nutritional status as an adjusted predictor of adverse postoperative events.

There were 3184 ALIF cases, including 1,275 (40%) of which had preoperative serum albumin levels. 53 (4.15%) patients were classified as having poor nutrition status. Poor preoperative nutritional status was shown to be a strong independent predictor of length of stay ≥5 days (OR = 2.56, 95% CI 1.43-4.59, P = .002), urinary tract infection (OR = 5.93, 95% CI 2.11-16.68, P = .001), and sepsis (OR = 5.35, 95% CI 1.13-25.42, P = .035) compared to patients with normal preoperative serum albumin levels.

Our analysis shows that patients with poor nutritional status before ALIF are independently at risk for sepsis as well as increased length of stay and urinary tract infection.

Retrospective.

To evaluate the efficacy of S2 alar screws in surgery for correction of adult spinal deformity (ASD).

We retrospectively reviewed the cases of 23 patients (mean follow-up: 18.5 months, minimum 12 months) who underwent corrective surgery for ASD using S2 alar screws as anchors for instrumentation of lower vertebrae. The background of the patients and their spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], lumbar lordosis [LL], thoracic kyphosis [TK], sagittal vertical axis [SVA], and PI-LL) were evaluated.

LL was improved from 9.7 ± 20.5° and SVA from 141.0 ± 64.0 mm before surgery to 39.0 ± 9.6° and 51.7 ± 40.8 mm immediately after surgery, respectively, and 38.2 ± 12.7° and 70.5 ± 59.2 mm at final follow-up. In 13 patients without sufficient correction (postoperative PI-LL ≥10°), bone mineral density and postoperative LL were significantly less, and PI, PI-LL, and PT were significantly greater than in patients with postoperative PI-LL <10°, suggesting that these are risk factors for undercorrection. In 5 patients, SVA increased more than 40 mm during follow-up. Postoperative LL was significantly less (31.4° vs 41.0°) and postoperative PI-LL was significantly greater (21.6° vs 9.3°) in these patients, suggesting a PI-LL mismatch induces postoperative progression of global malalignment.

Use of S2 alar screws as anchors for instrumentation in ASD surgery should be restricted. Their use might be an option for patients with low PI, and without severe osteoporosis, in whom efficient surgical correction can be obtained.

Retrospective radiographic review.

Our objectives were to (1) compare the ability of fulcrum bend radiographs and traction radiographs under general anesthesia to predict correction of adolescent idiopathic scoliosis (AIS) using pedicle screw only constructs and (2) compare the fulcrum bend correction index (FBCI) with a new measurement: the traction correction index (TCI).

This is a retrospective radiographic review of 80 AIS patients (62 female and 18 male), who underwent scoliosis correction with pedicle screw only constructs. The mean age at surgery was 14 years (range 9-20 years). Radiographic analysis was carried out on the preoperative and immediate postoperative posteroanterior standing radiographs and the preoperative fulcrum bend radiographs and traction radiographs under general anesthesia. FBCI is calculated by dividing the correction rate by the fulcrum flexibility and TCI is calculated by dividing the correction rate by the traction flexibility.

Preoperative mean Cobb angle of 63.9° was corrected to 25.8° postoperatively. The mean fulcrum bending Cobb angle was 37.6° and traction Cobb angle was 26.6°. The mean fulcrum flexibility was 41.1%, traction flexibility 58.4%, and correction rate 59.6%. The median FBCI was 137% and TCI was 104.3%.

When comparing fulcrum bend and traction radiographs, we found the traction radiographs to be more predictive of curve correction in AIS using pedicle screw constructs. TCI takes into account the curve flexibility better than FBCI.

Propensity score matched retrospective cohort study.

Obesity is a major confounder in determining the independent effect of metabolic syndrome (MetS) on complications after spinal surgery. The purpose of this study is to differentiate MetS from obesity as an independent influence on perioperative outcomes after elective lumbar spine fusion.

One- to 3-level posterior spinal fusion cases were identified from the 2011-2014 American College of Surgeons’ National Surgical Quality Improvement Program. To determine the effects of MetS outside of obesity itself, patients with MetS were first compared to a no-MetS cohort and then to an obese-only no-MetS cohort. Two propensity score matches based on demographics, comorbidities, surgical complexity, and diagnosis were used to match patients in 1:1 ratios and compare outcomes. Logistic regression with propensity score adjustment was further utilized as a secondary method of reducing selection bias.

Out of 18 605 patients that met criteria for inclusion, 1903 (10.2%) met our definition of MetS. Patients with MetS had a higher rate of wound complications (3.8% vs 2.7% obese no MetS, P = .045; vs 2.6% no MetS, P = .035), readmissions (7.4% vs 2.2% obese no MetS, P < .001; vs 4.6% no MetS, P < .001), and extended length of stay (29.1% vs 23.9% obese no MetS, P < .001; vs 23.5% no MetS, P < .001). Patients with MetS were more likely to experience a wound complication (odds ratio = 1.47, 95% confidence interval = 1.02-2.12) or readmission (odds ratio = 1.48, 95% confidence interval = 1.22-1.80).

Even after controlling for obesity, MetS is an independent risk factor for adverse short-term outcomes. These findings have various implications for preoperative risk stratification and reduction strategies.

A retrospective case-control study.

To determine factors influencing the ability to achieve coronal balance following spinal deformity surgery.

Following institutional ethics approval, the radiographs of 47 patients treated for spinal deformity surgery with long fusions to the pelvis, were retrospectively reviewed. The postoperative measurements included coronal balance, L4 tilt, and L5 tilt, levels fused, apical vertebral translation and maximum Cobb angle. L4 and L5 tilt angles were measured between the superior endplate and the horizontal. Sagittal parameters including thoracic kyphosis, lumbar lordosis, pelvic incidence, and sagittal vertical axis were recorded. Coronal balance was defined as the distance between the central sacral line and the mid body of C7 being ≤40 mm. Surgical factors, including levels fused, use of iliac fixation with and without connectors, use of S2A1 screws, interbody devices, and osteotomies. Statistical tests were performed to determine factors that contribute to postoperative coronal imbalance.

Of the 47 patients reviewed, 32 were balanced after surgery and 14 were imbalanced. Coronal balance was 1.30 cm from center in the balanced group compared to 4.83 cm in the imbalanced group (P < .01). Both L4 and L5 tilt were statistically different between the groups. Gender and the use of transverse connectors differed between the groups but not statistically.

In adult spinal deformity patients undergoing primary fusions to the pelvis, the ability to level the coronal tilt of L4 and L5 had the greatest impact on the ability to achieve coronal balance in this small series. A larger prospective series can help validate this important finding.

Retrospective study.

Treatment of spinal tuberculosis in the elderly involves consideration of compromised physiology, which often poses a clinical challenge to the surgeons to balance surgical safety versus deteriorating function. Frailty scoring has been reported as an effective tool to predict mortality and morbidity in cardiovascular surgery and recently in hip fractures. Its use in spinal surgery is scarcely reported.

We included elderly patients operated for spinal tuberculosis. Demographic, clinical and radiological profile with operative details of instrumentation, blood loss, surgical duration and mortality were noted. Modified frailty score (MFS) was calculated for each patient. There were 26 patients (males 9, females 17) with a mean age of 73.2 years. The patients were divided into those with 30-day postoperative mortality (M) and those who survived (S). The null hypothesis was that the MFS was comparable in both the groups.

The M group had 5 patients (19.2%) and the S group consisted of 21 patients. There was no statistical difference between the groups with regard to mean age, sex, number of medical comorbidities, ASA (American Society of Anesthesiologists) grade, Frankel grade C or worse, blood loss, and operative time. The mean MFS in M group was 5 and in S group was 1.8, which was statistically significant (P < .001).

Higher MFS is associated with postoperative 30-day mortality in the elderly patients with spinal tuberculosis undergoing surgery. It can be used as a guide to predict 30-day postoperative mortality in these patients.

Retrospective cohort study.

It is estimated that 10 000 patients seek medical care due to cervical radiculopathy every year in Denmark. Although the natural course is usually favorable, around 20% undergo surgery for cervical degenerative disease every year in Denmark. We aim to evaluate the patient-reported results and satisfaction of anterior cervical decompression and fusion over a 5-year period from a single Danish center for spine surgery.

This study is a retrospective study based on prospectively collected data from 318 consecutive patients treated with anterior cervical decompression and fusion over 1 to 3 levels. Data in the DaneSpine registry was collected pre- and postoperatively, and at 1 year after surgery. The outcome measures were Neck Disability Index (NDI), European Quality of Life 5D (EQ-5D), visual analogue score (VAS), and Short Form-36 Physical Component Summary (SF-36 PCS).

Of 318 cases enrolled, 272 (85.5%) had follow-up data available at a minimum 1-year postoperatively. The mean preoperative NDI was 40.0 and improved to 22.7. Mean EQ-5D was 0.50 and improved to 0.70, and mean VAS arm was 60.4 improved to 26.4. All improvements were statistically significant. A total of 74.3% were back to work 1 year after surgery. Achieving minimal clinically important difference (MCID) in VAS neck and SF-36 PCS was strongly correlated to patient satisfaction.

Patients who undergo anterior cervical discectomy and fusion can expect improvement in their pain and disability, with 74.3% of patients reporting a positive change in health status after surgery.

Retrospective cohort study.

To investigate age-based changes in cervical alignment parameters in an asymptomatic population.

Retrospective review of a prospective study of 118 asymptomatic subjects who underwent biplanar imaging with 3-dimensional capabilities. Demographic and health-related quality of life data was collected prior to imaging. Patients were stratified into 5 age groups: <35 years, 35-44 years, 45-54 years, 55-64 years, and ≥65 years. Radiographic measurements of the cervical spine and spinopelvic parameters were compared between age groups. The normal distribution of parameters was assessed followed by analysis of variance for comparison of variance between age groups.

C2-C7 lordosis, C0-C7 lordosis, and T1 slope demonstrated significant increases with age. C0-C7 lordosis was significantly less in subjects <35 years compared with ≥55 years. Significant differences in T1 slope were identified in patients <35 versus ≥65, 35-44 versus ≥65, and 45-54 versus ≥65 years. T1 slope demonstrated a positive correlation with age. Horizontal gaze parameters did not change linearly with age and mean averages of all age groups were within 10° of one another. Cervical kyphosis was present in approximately half of subjects who were <55 compared with approximately 10% of subjects ≥55 years. Differences in pelvic tilt, pelvic incidence-lumbar lordosis, and C7-S1 sagittal vertical axis were identified with age.

C0-C7 lordosis, C2-C7 lordosis, and T1 slope demonstrate age-based changes while other cervical and horizontal gaze parameters remain relatively constant with age.

Retrospective cohort.

Alterations in lumbar paraspinal muscle cross-sectional area (CSA) may correlate with lumbar pathology. The purpose of this study was to compare paraspinal CSA in patients with degenerative spondylolisthesis and severe lumbar disability to those with mild or moderate lumbar disability, as determined by the Oswestry Disability Index (ODI).

We retrospectively reviewed the medical records of 101 patients undergoing lumbar fusion for degenerative spondylolisthesis. Patients were divided into ODI score ≤40 (mild/moderate disability, MMD) and ODI score >40 (severe disability, SD) groups. The total CSA of the psoas and paraspinal muscles were measured on preoperative magnetic resonance imaging (MRI).

There were 37 patients in the SD group and 64 in the MMD group. Average age and body mass index were similar between groups. For the paraspinal muscles, we were unable to demonstrate any significant differences in total CSA between the groups. Psoas muscle CSA was significantly decreased in the SD group compared with the MMD group (1010.08 vs 1178.6 mm², P = .041). Multivariate analysis found that psoas CSA in the upper quartile was significantly protective against severe disability (P = .013).

We found that patients with severe lumbar disability had no significant differences in posterior lumbar paraspinal CSA when compared with those with mild/moderate disability. However, severely disabled patients had significantly decreased psoas CSA, and larger psoas CSA was strongly protective against severe disability, suggestive of a potential association with psoas atrophy and worsening severity of lumbar pathology.

Retrospective study.

There have been few reports of adjacent segment disease (ASD) after posterior lumbar interbody fusion (PLIF) with large numbers and long follow-up. The purpose of this study was to investigate (1) ASD incidence and time periods after primary PLIF, (2) repeat ASD incidence and time periods, and (3) ASD incidence and time periods by fusion length, age, and preoperative pathologies.

A total of 1000 patients (average age 67 years, average follow-up 8.3 years) who underwent PLIF for degenerative lumbar disorders were reviewed. ASD was defined as a symptomatic condition in which revision surgery was required.

The overall ASD rate was 9.0%, and the average ASD period was 4.7 years after primary surgery. With respect to clinical features of ASD, degenerative spondylolisthesis at the cranial fusion segment was the most frequent. In terms of repeat ASD, second and third ASD incidences were 1.1% and 0.4%, respectively. As for ASD by fusion length, age, and preoperative pathologies, ASD incidence was increased by fusion length, while the time period to ASD was significantly shorter in elderly patients and those with degenerative lumbar scoliosis.

In the present study, the overall ASD incidence was 9.0%, and the average ASD period was 4.7 years after primary operation. Second and third ASD incidences were 1.1% and 0.4%, respectively. Fusion length affected the ASD incidence, while aging factor and preoperative pathology affected the ASD time period.

Descriptive analysis using publicly available data.

The purpose of this study was 2-fold: to assess patient-rated trustworthiness of spine surgeons as a whole and to assess if academic proclivity, region of practice, or physician sex affects ratings of patient perceived trust.

Orthopedic spine surgeons were randomly selected from the North American Spine Society directory. Surgeon profiles on 3 online physician rating websites, HealthGrades, Vitals, and RateMDs were analyzed for patient-reported trustworthiness. Whether or not the surgeon had published a PubMed-indexed paper in 2016 was assessed with regard to trustworthiness scores. Total number of publications was also assessed. Individuals with >300 publications were excluded due to the likelihood of repeat names.

Recent publication and total number of publications has no relationship with online patient ratings of trustworthiness across all surgeons in this study. Region of practice likewise has no influence on mean trust ratings, yet varied levels of correlation are observed. Furthermore, there was no difference in trust scores between male and female surgeons.

Total academic proclivity via indexed publications does not correlate with patient perceived physician trustworthiness among spine surgeons as reported on physician review websites. Furthermore, region of practice within the United States does not have an influence on these trust scores. Likewise, there is no difference in trust score between female and male spine surgeons. This study also highlights an increasing utility for physician rating websites in spine surgery for evaluating and monitoring patient perception.

A retrospective study.

To investigate surgical outcomes and limitations of decompression surgery for degenerative spondylolisthesis.

One hundred patients with degenerative spondylolisthesis who underwent decompression surgery alone were included in this study. The average follow-up period was 3.7 years. Radiography and magnetic resonance imaging were used for radiological assessment. Patients with a recovery rate of >50% throughout the study period were classified as the control group (Group C), while those with a recovery rate of <50% throughout the study period were classified as the poor group (Group P). Patients that had improved symptoms, and yet later showed neurological deterioration due to foraminal stenosis at the same level were classified as the exiting nerve root radiculopathy group (Group E), while those who showed deterioration due to slip progression at the same level were classified as the traversing nerve root radiculopathy group (Group T).

Patient distribution in each group was 73, 12, 7, and 8 in Groups C, P, E, and T, respectively. As for preoperative radiological features, slippage and an upper migrated disc in Group P, disc wedging and an upper migrated disc in Group E, and lamina inclination and posterior opening in Group T were evident. The cutoff value of preoperative slippage with a poor outcome was 13%.

Surgical outcomes of decompression surgery for degenerative spondylolisthesis were successful in 73% cases. Preoperative radiological features for poor outcomes were slippage of more than 13%, an upper migrated disc, disc wedging, and lamina inclination.

Systematic review.

Diagnosis of pseudarthrosis after anterior cervical fusion is difficult, and often depends on the surgeon’s subjective assessment because recommended radiographic criteria are lacking. This review evaluated the available evidence for confirming fusion after anterior cervical surgery.

Articles describing assessment of anterior cervical fusion were retrieved from MEDLINE and SCOPUS. The assessment methods and fusion rates at 1 and 2 years were evaluated to identify reliable radiographical criteria.

Ten fusion criteria were described. The 4 most common were presence of bridging trabecular bone between the endplates, absence of a radiolucent gap between the graft and endplate, absence of or minimal motion between adjacent vertebral bodies on flexion-extension radiographs, and absence of or minimal motion between the spinous processes on flexion-extension radiographs. The mean fusion rates were 90.2% at 1 year and 94.7% at 2 years. The fusion rate at 2 years had significant independence (P = .048).

The most common fusion criteria, bridging trabecular bone between the endplates and absence of a radiolucent gap between the graft and endplate, are subjective. We recommend using <1 mm of motion between spinous processes on extension and flexion to confirm fusion.

A narrative literature review.

To review the surgical techniques of posterior screw fixation in the subaxial cervical spine.

A broad literature review on the most common screw fixation techniques including lateral mass, pedicle, intralaminar and transfacet screws was performed on PubMed. The techniques and surgical nuances are summarized.

The following techniques were described in detail and presented with illustrative figures, including (1) lateral mass screw insertion: by Roy-Camille, Louis, Magerl, Anderson, An, Riew techniques and also a modified technique for C7 lateral mass fixation; (2) pedicle screw fixation technique as described by Abumi and also a freehand technique description; (3) intralaminar screw fixation; and finally, (4) transfacet screw fixation, as described by Takayasu, DalCanto, Klekamp, and Miyanji.

Many different techniques of subaxial screw fixation were described and are available. To know the nuances of each one allows surgeons to choose the best option for each patient, improving the success of the fixation and decrease complications.

A literature review.

An evaluation of the contaminants prevalent on implants used for surgery and the aseptic methods being employed against them.

PubMed was searched for articles published between 2000 and 2017 for studies evaluating the contaminants present on spine implants, and associated pre- and intraoperative implant processing and handling methodology suggested to avoid them. Systematic reviews, observational studies, bench-top studies, and expert opinions were included.

Eleven studies were identified whose major focus was the asepsis of implants to reduce the incidence of surgical site infection incidences during surgery. These studies measured the colony forming units of bacteria on sterilized implants and/or gloves from the surgeon, scrub nurse, and assistants, as well as reductions of surgical site infection rates in spine surgery due to changes in implant handling techniques. Additionally, the search included assessments of endotoxins and carbohydrates present on reprocessed implants. The suggested changes to surgical practice based on these studies included handling implants with only fresh gloves, keeping implants covered until the immediate time of use, reducing operating room traffic, avoiding reprocessing of implants (ie, providing terminally sterilized implants), and avoiding touching the implants altogether.

Both reprocessing (preoperative) and handling (intraoperative) of implants seem to lead to contamination of sterilized implants. Using a terminally sterilized device may mitigate reprocessing (preoperative implant prophylaxis), whereas the use of fresh gloves for handling each implant and/or a permanent shielding technique (intraoperative implant prophylaxis) could potentially avoid recontamination at the theatre.