A Review of Vitamin D in Spinal Surgery: Deficiency Screening, Treatment, and Outcomes.

In this review, we discuss the demonstrated value of vitamin D in bone maintenance, fracture resistance, spinal health, and spine surgery outcomes. Despite this, the effect of vitamin D levels in spine surgery has not been well described. Through this review of literature, several conclusions were drawn. First, despite the fact that a high number of spine surgery patients are vitamin D deficient, screening is not commonly performed. Second, adequate vitamin D levels will not be achieved in a majority of these patients without supplementation. Last, inadequate vitamin D levels may increase the risk of pseudarthrosis. Given these findings, we suggest that many patients undergoing spinal surgery could be treated with vitamin D supplementation prior to surgery without the need for confirmatory testing for vitamin D deficiency. This is a more cost-effective method than screening all patients. However, future randomized trials and cost-effectiveness analyses are needed to determine the ultimate effects of vitamin D supplementation on clinical morbidity and surgical outcomes.

Etiology-Based Classification of Adjacent Segment Disease Following Lumbar Spine Fusion.

BACKGROUND: Adjacent segment disease (ASDz) is a potential complication following lumbar spinal fusion. A common nomenclature based on etiology and ASDz type does not exist and is needed to assist with clinical prognostication, decision making, and management. QUESTIONS/PURPOSES: The objective of this study was to develop an etiology-based classification system for ASDz following lumbar fusion. METHODS: We conducted a retrospective chart review of 65 consecutive patients who had undergone both a lumbar fusion performed by a single surgeon and a subsequent procedure for ASDz. We established an etiology-based classification system for lumbar ASDz with the following six categories: "degenerative" (degenerative disc disease or spondylosis), "neurologic" (disc herniation, stenosis), "instability" (spondylolisthesis, rotatory subluxation), "deformity" (scoliosis, kyphosis), "complex" (fracture, infection), or "combined." Based on this scheme, we determined the rate of ASDz in each etiologic category. RESULTS: Of the 65 patients, 27 (41.5%) underwent surgery for neurogenic claudication or radiculopathy for adjacent-level stenosis or disc herniation and were classified as "neurologic." Ten patients (15.4%) had progressive degenerative disc pathology at the adjacent level and were classified as "degenerative." Ten patients (15.4%) had spondylolisthesis or instability and were classified as "instability," and three patients (4.6%) required revision surgery for adjacent-level kyphosis or scoliosis and were classified as "deformity." Fifteen patients (23.1%) had multiple diagnoses that included a combination of categories and were classified as "combined." CONCLUSION: This is the first study to propose an etiology-based classification scheme of ASDz following lumbar spine fusion. This simple classification system may allow for the grouping and standardization of patients with similar pathologies and thus for more specific pre-operative diagnoses, personalized treatments, and improved outcome analyses.

In Degenerative Spondylolisthesis, Unilateral Laminotomy for Bilateral Decompression Leads to Less Reoperations at 5 Years When Compared to Posterior Decompression With Instrumented Fusion: A Propensity-matched Retrospective Analysis.

STUDY DESIGN: Multicenter retrospective cohort study. OBJECTIVE: The aim of this study was to compare reoperation rates at 5-year follow-up of unilateral laminotomy for bilateral decompression (ULBD) versus posterior decompression with instrumented fusion (Fusion) for patients with low-grade degenerative spondylolisthesis (DS) with lumbar spinal stenosis (LSS) in a multicenter database. SUMMARY OF BACKGROUND DATA: Controversy exists regarding whether fusion should be used to augment decompression surgery in patients with LSS with DS. For years, the standard has been fusion with standard laminectomy to prevent postoperative instability. However, this strategy is not supported by Level 1 evidence. Instability and reoperations may be reduced or prevented using less invasive decompression techniques. METHODS: We identified 164 patients with DS and LSS who underwent ULBD between January 2007 and December 2011 in a multicenter database. These patients were propensity score-matched on age, sex, race, and smoking status with patients who underwent Fusion (n = 437). Each patient required a minimum of 5-year follow-up. The primary outcome was 5-year reoperation. Secondary outcome measures included postoperative complication rates, blood loss during surgery, and length of stay. Logistic regression models were used to estimate the odds ratio of the 5-year reoperation rate between the two surgical groups. RESULTS: The reoperation rate at 5-year follow-up was 10.4% in the ULBD group and 17.2% in the Fusion group. ULBD reoperations were more frequent at the index surgical level; Fusion reoperations were more common at an adjacent level. The two types of operations had similar postoperative complication rates, and both groups tended to have fusion reoperations. CONCLUSION: For patients with stable DS and LSS, ULBD is a viable, durable option compared to fusion with decreased blood loss and length stay, as well as a lower reoperation rate at 5-year follow-up. Further prospective studies are required to determine the optimal clinical scenario for ULBD in the setting of DS. LEVEL OF EVIDENCE: 3.

Radiographic Analysis of Psoas Morphology and its Association With Neurovascular Structures at L4-5 With Reference to Lateral Approaches.

STUDY DESIGN: Retrospective imaging review. OBJECTIVE: Utilize magnetic resonance imaging (MRI) to expand the anatomical description of psoas morphology and its association with neurovascular structures at L4-5. SUMMARY OF BACKGROUND DATA: Anatomical psoas muscle variants may present a greater risk of neurovascular injury at the L4-5 level during lateral transpsoas approaches. METHODS: Axial L4-5 sections of consecutive patients who obtained lumbar MRIs were analyzed. Teardrop psoas morphology was assessed qualitatively. MRI described psoas morphology and proximity of neurovascular structures, whereas plain radiographs were evaluated for lumbosacral transitional vertebrae (LSTV). Teardrop morphology was tested for associations with radiographic measurements using t tests and χ analysis. RESULTS: Fifty teardrop and 476 nonteardrop psoas muscles were identified. Teardrop morphology was associated with greater longitudinal length (53.1 vs. 49.3 mm, P = 0.012), and shorter transverse length (34.9 vs. 44.8 mm, P < 0.001) compared with nonteardrop. Teardrop morphology was associated with anterior and lateral migration of the psoas with greater distance between the anterior borders of the psoas and disc (13.5 vs. 6.3 mm, P < 0.001), and greater distance between the medial border of the psoas to the lateral disc border (1.6 vs. 0.5 mm, P < 0.001). Teardrop morphology was associated with a higher incidence of the lumbar plexus migrating anteriorly adjacent to the middle-third of the disc (43.4% vs. 17.6%, P < 0.001) and the iliac vasculature being more laterally and posteriorly located, adjacent to the anterior-third of the disc (43.4% vs. 30.0%, P = 0.047). Teardrop morphology was not associated with presence of LSTV (3.8% vs. 7.6%, P = 0.306). CONCLUSION: The current study provides detailed metrics of teardrop psoas muscles and surrounding structures. The study confirms that the presence of teardrop anatomy on L4-5 axial imaging is associated with anterior migration of the lumbar plexus and posterolateral migration of the iliac vasculature which may increase the risk of neurovascular injury during direct and oblique-lateral lumbar spine procedures. LEVEL OF EVIDENCE: 3.

Stability-preserving decompression in degenerative versus congenital spinal stenosis: demographic patterns and patient outcomes.

BACKGROUND CONTEXT: Although lumbar spinal stenosis often presents as a degenerative condition (degenerative stenosis [DS]), some patients present with symptoms from lifelong narrowing of the spinal canal. These patients have congenital stenosis (CS) and present with symptoms of stenosis at a younger age. Patients with CS often have a distinct pathophysiology with fewer degenerative changes but present with multilevel involvement. In the setting of neurologic symptoms, decompression alone while preserving stability has been proposed for both patient populations. PURPOSE: The purpose of this study is to evaluate if the different etiology for narrowing in CS and DS results in a different natural history of pain progression, different locations requiring decompression, and different outcomes following a stability-preserving decompression procedure. STUDY DESIGN/SETTING: This study used a retrospective cohort study patient sample: We retrospectively reviewed consecutive patients of a single surgeon with DS or CS who underwent surgical decompression without fusion between 2008 and 2014. Patients were excluded if they had undergone a previous lumbar surgical procedure (decompression or fusion) or follow-up less than 12 months. OUTCOME MEASURES: Pre- and postoperative clinical outcome scores including visual analogue scale (VAS) and Oswestry Disability Index (ODI) were recorded. Postoperatively, data were collected regarding complications, the presence of new radicular or myelopathic symptoms, and necessity of reoperation in the lumbar spine. METHODS: Demographic information included age, sex, body mass index, smoking status, and Charleston Comorbidity Index (CCI). Preoperative clinical symptoms as well as the presence of lower extremity radiculopathy and claudication were evaluated. Patients were determined to have a diagnosis of CS by the treating surgeon if primary radiographs revealed shortened pedicles and decreased cross-sectional area of the spinal canal as detailed by previous studies. Binary outcomes were compared between congenital and degenerative cohorts using bivariate and multivariate logistic regression. Multivariate regressions controlled for baseline patient and operative characteristics. RESULTS: The average age of the DS cohort was 66.7±10.7 years, whereas for the CS group, it was 47.1±9.2 years. Average follow-up was 27.6 months. The patients with DS had significantly more comorbidities as shown by the CCI score (2.8±1.6 vs. 0.5±0.6); p<.001) and the American Society of Anesthesiologists (ASA) score ≥3 (52.8% vs. 11.1%; p<.001). Patients with CS presented with higher VAS back (8.0 vs. 5.1; p=.008) and leg (7.9 vs. 4.5; p<.001) scores. Patients with DS presented with significantly greater duration of preoperative back pain and leg pain (42.7 vs. 30.5 months; p=.042). Postoperatively, there were no significant differences in VAS back, leg, or ODI scores. However, a trend toward a lower VAS leg score was present in the patients with CS when compared with patients with DS (2.6±3.0 vs. 4.2±3.2; p<.117). Both patient groups experienced similar levels of symptomatic relief and improvement in VAS and ODI scores. There were no significant differences in new-onset radicular symptoms requiring conservative treatment or reoperation. In both groups combined, 81.9% of patients reported resolution of lower extremity symptoms at final follow-up. Overall, 20.6% of patients experienced new lower-extremity radicular symptoms after a period of resolution of symptoms postoperatively. There were significantly more reoperations following surgical decompression in patients with DS (13.9% vs. 2.8%; p=.02). CONCLUSIONS: Patients with CS and patients with DS respond well to decompression alone, without a supplemental fusion, despite differences in pain experience and presentation. The localization of pathology requiring decompression is similar. The patients with DS were more susceptible to require another operation resulting in a fusion, which confirms the theory that initial microinstability can progress in DS, but is likely not part of the disease process in CS. At just over 2 years after decompression, patients with CS may not need to be treated by a fusion in the setting of lower back pain; however, longer-term follow up is necessary to further assess these outcomes.

Preoperative mental health status may not be predictive of improvements in patient-reported outcomes following an anterior cervical discectomy and fusion.

OBJECTIVE Prior studies have correlated preoperative depression and poor mental health status with inferior patient-reported outcomes following lumbar spinal procedures. However, literature regarding the effect of mental health on outcomes following cervical spinal surgery is limited. As such, the purpose of this study is to test for the association of preoperative SF-12 Mental Component Summary (MCS) scores with improvements in Neck Disability Index (NDI), SF-12 Physical Component Summary (PCS), and neck and arm pain following anterior cervical discectomy and fusion (ACDF). METHODS A prospectively maintained surgical database of patients who underwent a primary 1- or 2-level ACDF during 2014-2015 was reviewed. Patients were excluded if they did not have complete patient-reported outcome data for the preoperative or 6-week, 12-week, or 6-month postoperative visits. At baseline, preoperative SF-12 MCS score was assessed for association with preoperative NDI, neck visual analog scale (VAS) score, arm VAS score, and SF-12 PCS score. The preoperative MCS score was then tested for association with changes in NDI, neck VAS, arm VAS, and SF-12 PCS scores from the preoperative visit to postoperative visits. These tests were conducted using multivariate regression controlling for baseline characteristics as well as for the preoperative score for the patient-reported outcome being assessed. RESULTS A total of 52 patients were included in the analysis. At baseline, a higher preoperative MCS score was negatively associated with a lower preoperative NDI (coefficient: -0.74, p < 0.001) and preoperative arm VAS score (-0.06, p = 0.026), but not preoperative neck VAS score (-0.03, p = 0.325) or SF-12 PCS score (0.04, p = 0.664). Additionally, there was no association between preoperative MCS score and improvement in NDI, neck VAS, arm VAS, or SF-12 PCS score at any of the postoperative time points (6 weeks, 12 weeks, and 6 months, p > 0.05 for each). The percentage of patients achieving a minimum clinically important difference at 6 months did not differ between the bottom and top MCS score halves (p > 0.05 for each). CONCLUSIONS The results of this study suggest that better preoperative mental health status is associated with lower perceived preoperative disability but is not associated with severity of preoperative neck or arm pain. In contrast to other studies, the present study was unable to demonstrate that preoperative mental health is predictive of improvement in patient-reported outcomes at any postoperative time point following an ACDF.

Case of a Missed Giant Cell Tumor of Bone: An Opportunity to Observe its Natural History Disease.

Giant cell tumor of bone (GCT) is a benign neoplasm that most commonly presents with pain and is rarely diagnosed as an incidental finding. We present the report of a young woman whose pre-operative MRI was only noted to have a tear of the anterior cruciate ligament (ACL). Subsequently, the patient underwent anACL reconstruction. A second MRI, performed four years later, demonstrated an enlarged mass in the same location. A retrospective evaluation of the initial MRI revealed an eccentric metaphyseal lesion. Histology obtained from the lesion demonstrated a giant cell tumor of bone. We present the case of an asymptomatic GCT discovered retrospectively as an incidental finding and reevaluated four years later. 'Ihis case serves as a reminder of the importance for the critical review of routine preoperative imaging and also offers a unique perspective on the natural history of giant cell tumor of bone.

Comparison of 368 patients undergoing surgery for lumbar degenerative spondylolisthesis from the SPORT trial with 955 from the NSQIP database.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To compare demographics and perioperative outcomes between the Spine Patient Outcomes Research Trial (SPORT) lumbar degenerative spondylolisthesis arm and a similar population from the National Surgical Quality Improvement Program (NSQIP) database. SUMMARY OF BACKGROUND DATA: SPORT is a well-known surgical trial that investigated the benefits of surgical versus nonsurgical treatment in patients with various lumbar pathologies. However, the external validity of SPORT demographics and outcomes has not been fully established. METHODS: Surgical degenerative spondylolisthesis cases were identified from NSQIP between 2010 and 2012. This population was then compared with the SPORT degenerative spondylolisthesis study. These comparisons were based on published data from SPORT and included analyses of demographics, perioperative factors, and complications. RESULTS: The 368 surgical patients with degenerative spondylolisthesis in SPORT were compared with 955 patients identified in NSQIP. Demographic comparisons were as follows: average age and race (no difference; P > 0.05 for each), sex (9.1% more female patients in SPORT; P = 0.002), smoking status (6.6% more smokers in NSQIP; P = 0.002), and average body mass index (1.1 kg/m greater in NSQIP; P = 0.005). Larger differences were noted in what surgical procedure was performed (P < 0.001), with the most notable difference being that the NSQIP population was much more likely to include interbody fusion than the SPORT population (52.4% vs. 12.5%). Most perioperative factors and complication rates were similar, including average operative time, wound infection, wound dehiscence, postoperative transfusion, and postoperative mortality (no differences; P > 0.05 for each). Average length of stay was shorter in NSQIP compared with SPORT (3.7 vs. 5.8 d; P = 0.042). CONCLUSION: Though important differences in the distribution of surgical procedures were identified, this study supports the greater generalizability of the surgical SPORT degenerative spondylolisthesis study based on similar demographics and perioperative outcomes when compared with patients from the NSQIP database. LEVEL OF EVIDENCE: 3.

Comparison of the lumbar disc herniation patients randomized in SPORT to 6,846 discectomy patients from NSQIP: demographics, perioperative variables, and complications correlate well.

BACKGROUND CONTEXT: The Spine Patient Outcomes Research Trial (SPORT) is a highly referenced clinical trial that randomized patients with lumbar pathology to receive surgery or continued conservative treatment. PURPOSE: The purpose of this study was to compare the SPORT lumbar disc herniation cohort and an analogous cohort from the National Surgical Quality Improvement Program (NSQIP) database. STUDY DESIGN/SETTING: This is a retrospective cohort study comparing a national database population to a randomized clinical trial. PATIENT SAMPLE: Elective lumbar discectomies from NSQIP between 2010 and 2012 were used. OUTCOME MEASURES: Demographics were compared between the randomized SPORT cohorts (surgical and nonoperative) and NSQIP. Perioperative factors and complications were then compared between SPORT discectomy patients and NSQIP. METHODS: Using current procedural terminology and International Classification of Diseases, ninth revision codes, all elective lumbar discectomies from NSQIP between 2010 and 2012 were identified. Where possible based on the published data and variables available in each cohort, the two populations were compared. RESULTS: A total of 6,846 NSQIP discectomy patients were compared with the randomized SPORT surgical and nonoperative cohorts. Demographic comparisons showed that NSQIP patients were older (average age 48.2±14.5 years [mean±standard deviation] vs. 41.7±11.8 and 43.0±11.3 years, respectively [p<.001]) and had higher body mass index (29.6±6.2 kg/m(2) vs. 27.8±5.6 and 28.2±5.4 kg/m(2), respectively [p<.001]). No statistical differences existed for gender or race. Smoking status was not different between the SPORT nonoperative group and NSQIP but was higher in NSQIP compared with SPORT surgical patients (p=.020 by 7%). Comparisons of perioperative factors and complications between the SPORT surgical cohort and NSQIP showed no statistical difference in average operative time, length of stay, deep wound infections, wound dehiscence, total wound complications, or blood transfusions. Spine Patient Outcomes Research Trial superficial wound infection rates were higher than NSQIP (p=.029 by 1.4%). As expected, SPORT 1-year reoperation rates were higher than NSQIP 30-day rates (7% vs. 2%, p<.001). CONCLUSIONS: Spine Patient Outcomes Research Trial lumbar disc herniation results are similar to those from a large national patient sample. Even statistically significant differences would be considered clinically similar. These findings support the generalizability of the SPORT lumbar disc herniation results.

Use of an operating microscope during spine surgery is associated with minor increases in operating room times and no increased risk of infection.

STUDY DESIGN: Retrospective database review. OBJECTIVE: To evaluate whether microscope use during spine procedures is associated with increased operating room times or increased risk of infection. SUMMARY OF BACKGROUND DATA: Operating microscopes are commonly used in spine procedures. It is debated whether the use of an operating microscope increases operating room time or confers increased risk of infection. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database, which includes data from more than 370 participating hospitals, was used to identify patients undergoing elective spinal procedures with and without the use of an operating microscope for the years 2011 and 2012. Bivariate and multivariate linear regressions were used to test the association between microscope use and operating room times. Bivariate and multivariate logistic regressions were similarly conducted to test the association between microscope use and infection occurrence within 30 days of surgery. RESULTS: A total of 23,670 elective spine procedures were identified, of which 2226 (9.4%) used an operating microscope. The average patient age was 55.1±14.4 years. The average operative time (incision to closure) was 125.7±82.0 minutes.Microscope use was associated with minor increases in preoperative room time (+2.9 min, P=0.013), operative time (+13.2 min, P<0.001), and total room time (+18.6 min, P<0.001) on multivariate analysis.A total of 328 (1.4%) patients had an infection within 30 days of surgery. Multivariate analysis revealed no significant difference between the microscope and nonmicroscope groups for occurrence of any infection, superficial surgical site infection, deep surgical site infection, organ space infection, or sepsis/septic shock, regardless of surgery type. CONCLUSION: We did not find operating room times or infection risk to be significant deterrents for use of an operating microscope during spine surgery. LEVEL OF EVIDENCE: 3.

Factors predictive of increased surgical drain output after anterior cervical discectomy and fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To identify factors that are independently associated with increased surgical drain output in patients who have undergone ACDF. SUMMARY OF BACKGROUND DATA: Surgical drains are typically placed after ACDF to reduce the risk of complications associated with neck hematoma. The orthopedic literature has repeatedly challenged the use of surgical drains after many procedures, and there are currently no guidelines for determining which patients are most likely to benefit from drain placement after ACDF. METHODS: Consecutive patients who underwent elective ACDF with surgical drain placement at a single academic institution between January 2011 and February 2013 were identified using billing records. Patient information was abstracted from the medical record. Patients were categorized on the basis of normal or increased total drain output, with increased drain output defined as total drain output 50th percentile (30 mL) or more. A multivariate logistic regression was used to determine which factors were independently associated with increased drain output. RESULTS: A total of 151 patients with ACDF met inclusion criteria. Total drain output was in the range from 0 mL to 265 mL. The average drain output for this cohort was 42.3 ± 45.5 mL (mean ± standard deviation). Among all patients in the study, 80 patients had increased drain output (drain output ≥50th percentile or 30 mL).Multivariate analysis identified 3 independent predictors of increased drain output: age 50 years or more (odds ratio [OR] = 3.9), number of levels (2 levels, OR = 2.7; 3-4 levels, OR = 17.0), and history of smoking (OR = 2.8). One patient developed a postoperative neck hematoma while a drain was in place. CONCLUSION: Patients with the factors associated with increased drain output identified in the earlier text may benefit most from surgical drain placement after ACDF. Nonetheless, neck hematoma is still possible even with drain use. LEVEL OF EVIDENCE: 3.

The surgical treatment of single level multi-focal subarticular and paracentral and/or far-lateral lumbar disc herniations: the single incision full endoscopic approach.

BACKGROUND: Surgery for same level multi-focal extruded lumbar disc herniations is technically challenging and the optimal method controversial. The subarticular disc herniation may pose the most challenging subtype requiring partial or complete facetectomy with or without fusion. The far-lateral disc herniation, often treated using a Wiltse approach, can also be difficult to access especially in the obese patient. When both the subarticular and far-lateral subtypes are simultaneously present at the same level with or without a paracentral disc herniation, a total facetectomy and interbody fusion (TLIF) or a total disc replacement (TDR) may be necessary. Endoscopic surgical techniques may reduce the need for these more invasive methods. METHODS: Fifteen patients (6 male and 9 female) who had same level multi-focal (subarticular as well as far-lateral and/or paracentral) extruded disc herniations underwent single incision unilateral endoscopic disc excision by the same surgeon at a single institution. Patients were prospectively followed for an average of 15.3 months (range 14-18 months) and outcomes were evaluated radiographically and clinically (Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). RESULTS: The mean operative time was 52 minutes with minimal blood loss in all cases. Fourteen of the 15 patients were discharged to home on the day of their surgery. The mean ODI and leg VAS scores improved from 22.9 ± 3.2 to 12.9 ± 2.7 (p < 0.005), and from 8.6 ± 1.6 to 2.1 + 0.4 (p < 0.005), respectively. CONCLUSIONS: After an average of 15.3 months of follow-up, the clinical and radiographic results of full endoscopic surgical treatment of single level multi-focal (subarticular as well as far-lateral and/or paracentral) disc herniations are excellent. This study is a case series with mid-term follow-up (Level IV). CLINICAL RELEVANCE: Foraminal and extra-foraminal full endoscopic decompression appears to offer a safe minimally invasive solution to a complex pathologic problem.

Dorsal spanning plate fixation for distal radius fractures.

In polytrauma patients, the presence of a multifragmentary distal radius fracture poses a challenge with respect to early mobilization. Dorsal spanning plate fixation is an alternative choice for these patients for providing definitive operative fixation of the distal radius fracture and for providing a construct to allow weight-bearing through the injured wrist for rehabilitative purposes. In this article, we describe the operative technique to place a dorsal spanning plate and provide a retrospective review of outcomes in polytrauma patients.