Are there differences in the reoperation rates for operative adjacent-segment disease between ALIF+PS, PLIF+PS, TLIF+PS, and LLIF+PS? An analysis of a cohort of 5291 patients.

OBJECTIVE: Biomechanical factors in lumbar fusions accelerate the development of adjacent-segment disease (ASD). Stiffness in the fused segment increases motion in the adjacent levels, resulting in ASD. The objective of this study was to determine if there are differences in the reoperation rates for symptomatic ASD (operative ASD) between anterior lumbar interbody fusion plus pedicle screws (ALIF+PS), posterior lumbar interbody fusion plus pedicle screws (PLIF+PS), transforaminal lumbar interbody fusion plus pedicle screws (TLIF+PS), and lateral lumbar interbody fusion plus pedicle screws (LLIF+PS). METHODS: A retrospective study using data from the Kaiser Permanente Spine Registry identified an adult cohort (≥ 18 years old) with degenerative disc disease who underwent primary lumbar interbody fusions with pedicle screws between L3 to S1. Demographic and operative data were obtained from the registry, and chart review was used to document operative ASD. Patients were followed until operative ASD, membership termination, the end of study (March 31, 2022), or death. Operative ASD was analyzed using Cox proportional hazards models. RESULTS: The final study population included 5291 patients with a mean ± SD age of 60.1 ± 12.1 years and a follow-up of 6.3 ± 3.8 years. There was a total of 443 operative ASD cases, with an overall incidence rate of reoperation for ASD of 8.37% (95% CI 7.6-9.2). The crude incidence of operative ASD at 5 years was the lowest in the ALIF+PS cohort (7.7%, 95% CI 6.3-9.4). In the adjusted models, the authors failed to detect a statistical difference in operative ASD between ALIF+PS (reference) versus PLIF+PS (HR 1.06 [0.79-1.44], p = 0.69) versus TLIF+PS (HR 1.03 [0.81-1.31], p = 0.83) versus LLIF+PS (HR 1.38 [0.77-2.46], p = 0.28). CONCLUSIONS: In a large cohort of over 5000 patients with an average follow-up of > 6 years, the authors found no differences in the reoperation rates for symptomatic ASD (operative ASD) between ALIF+PS and PLIF+PS, TLIF+PS, or LLIF+PS.

Primary anterior lumbar interbody fusion, with and without posterior instrumentation: a 1,377-patient cohort from a multicenter spine registry.

BACKGROUND CONTEXT: Lumbar interbody instrumentation techniques are common and effective surgical options for a variety of lumbar degenerative pathologies. Anterior lumbar interbody fusion (ALIF) has become a versatile and powerful means of decompression, stabilization, and reconstruction. As an anterior only technique, the integrity of the posterior muscle and ligaments remain intact. Adding posterior instrumentation to ALIF is common and may confer benefits in terms of higher fusion rate but could contribute to adjacent segment degeneration due to additional rigidity. Large clinical studies comparing stand-alone ALIF with and without posterior supplementary fixation (ALIF+PSF) are lacking. PURPOSE: To compare rates of operative nonunion and adjacent segment disease (ASD) in ALIF with or without posterior instrumentation. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Adult patients (≥18 years old) who underwent primary ALIF for lumbar degenerative pathology between levels L4 to S1 over a 12-year period. Exclusion criteria included trauma, cancer, infection, supplemental decompression, noncontiguous fusions, prior lumbar fusions, and other interbody devices. OUTCOME MEASURES: Reoperation for nonunion and ASD compared between ALIF only and ALIF+PSF. METHODS: Reoperations were modeled as time-to-events where the follow-up time was defined as the difference between the primary ALIF procedure and the date of the outcome of interest. Crude cumulative reoperation probabilities were reported at 5-years follow-up. Multivariable Cox proportional hazard regression was used to evaluate risk of operative nonunion and for ASD adjusting for patient characteristics. RESULTS: The study consisted of 1,377 cases; 307 ALIF only and 1070 ALIF+PSF. Mean follow-up time was 5.6 years. The 5-year crude nonunion incidence was 2.4% for ALIF only and 0.5% for ALIF+PSF; after adjustment for covariates, a lower operative nonunion risk was observed for ALIF+PSF (HR=0.22, 95% CI=0.06-0.76). Of the patients who are deemed potentially suitable for ALIF alone, one would need to add posterior instrumentation in 53 patients to prevent one case of operative nonunion at a 5-year follow-up (number needed to treat). Five-year operative ASD incidence was 4.3% for ALIF only and 6.2% for ALIF+PSF; with adjustments, no difference was observed between the cohorts (HR=0.96, 95% CI=0.54-1.71). CONCLUSIONS: While the addition of posterior instrumentation in ALIFs is associated with lower risk of operative nonunion compared with ALIF alone, operative nonunion is rare in both techniques (<5%). Accordingly, surgeons should evaluate the added risks associated with the addition of posterior instrumentation and reserve the supplemental posterior fixation for patients that might be at higher risk for operative nonunion. Rates of operative ASD were not statistically higher with the addition of posterior instrumentation suggesting concern regarding future risk of ASD perhaps should not play a role in considering supplemental posterior instrumentation in ALIF.

A Comparison of Surgical Outcomes Between Minimally Invasive and Open Thoracolumbar Corpectomy.

BACKGROUND: Minimally invasive (MIS) techniques have gained considerable attention for the management of degenerative spinal pathologies. However, few studies have compared the outcomes between MIS and open thoracolumbar corpectomies. The purpose of this study was to compare perioperative variables between MIS and open thoracolumbar corpectomy. METHODS: Retrospective review of 33 patients who underwent either an MIS or open thoracolumbar corpectomy by a single surgeon between 2005 and 2012 was performed. Patients were separated into anterior-posterior MIS (MIS AP), anterior-posterior open (AP), and posterior open (P) cohorts. Postoperative narcotic use was converted to oral morphine equivalents (OMEs). Demographics, comorbidity, perioperative variables, complications, and computed tomographic analyses were assessed. Fisher exact test was performed for categorical variables and Student t test for continuous variables. A P value of ≤ .05 denoted statistical significance. RESULTS: Thirty-three patients underwent an MIS AP, AP, or P thoracolumbar corpectomy (39.4% vs 15.2% vs 45.5%, respectively). MIS AP patients were younger with a lower comorbidity burden than either open cohorts. In addition, MIS AP patients demonstrated a decreased procedural time, lower blood loss, and shorter hospitalization than either open cohorts. MIS AP patients required less units of transfusion than P and AP patients while demonstrating lower postoperative narcotics consumption and reoperations rates than open AP patients. Surgical site infection rates, body mass index, intraoperative fluid requirements, and complication rates were similar between cohorts. All patients demonstrated successful arthrodesis at 1 year based upon computed tomography. CONCLUSIONS: MIS AP thoracolumbar corpectomy patients incurred decreased procedural times, shorter hospitalization, and lower blood loss compared with open patients. MIS AP patients demonstrated decreased postoperative narcotics consumption and reoperation rates compared with traditional AP patients. All patients demonstrated successful arthrodesis. CLINICAL RELEVANCE: The MIS approach to thoracolumbar corpectomies appears to be a safe and efficacious alternative when compared with traditional methods.

Rigid-Plating and Cortico-Cancellous Allograft Are Effective for 3-Level Anterior Cervical Discectomy and Fusion: Radiographic and Clinical Outcomes.

OBJECTIVE: To determine the risk factors associated with radiographic changes and clinical outcomes following 3-level anterior cervical discectomy and fusion (ACDF) using rigidplate constructs and cortico-cancellous allograft. ACDF has demonstrated efficacy for treatment of multilevel degenerative cervical conditions, but current data exists in small heterogeneous forms. METHODS: A retrospective review included 98 patients with primary 3-level ACDF surgery at one institution from 2008 to 2013 with minimum 1-year follow-up. Cervical sagittal vertical axis (SVA), segmental height, fusion, and lordosis radiographs were measured preoperatively and at 2 postoperative periods. RESULTS: Rates of asymptomatic pseudarthroses and total reoperations were 18% and 4%, respectively. Results demonstrated immediate improvements in cervical lordosis (5.5°, p < 0.01) and segmental height (5.0-mm increase, p < 0.01) with little changes in the cervical SVA (3.2-mm increase, p < 0.01). The segmental height decreased from immediate postoperative period to final follow-up (1.7-mm decrease, p < 0.01). Older age was protective against radiolucent lines (p < 0.05). Patient-reported outcomes significantly improved following surgery (p < 0.01). Current smoking status and diagnosis of diabetes mellitus had no impact on radiographic or clinical outcomes. Risk factors were not identified for the 5 reoperations (4%). CONCLUSION: Three-level ACDF with rigid-plating and cortico-cancellous allograft is an effective procedure for degenerative diseases of the cervical spine without the application of additional adjuncts or combined anteriorposterior cervical surgeries. Significant improvements in cervical lordosis, segmental height, and segmental alignment can be achieved with little change in cervical SVA and a low rate of reoperations over short-term follow-up. Similarly, patient-reported outcomes show significant improvements.

Comparison of Surgical Outcomes, Narcotics Utilization, and Costs After an Anterior Cervical Discectomy and Fusion: Stand-alone Cage Versus Anterior Plating.

STUDY DESIGN: Retrospective cohort analysis of a prospectively maintained registry. OBJECTIVE: To compare the surgical outcomes, narcotic utilization, and costs between a stand-alone (SA) cage and anterior plating (AP) with an interbody device for 1-level anterior cervical discectomy and fusion (ACDF). BACKGROUND DATA: ACDF with a SA cage has gained popularity as a potential alternative to anterior cervical plating. Few studies have compared the surgical outcomes, narcotic utilization, and costs of ACDF utilizing a SA cage versus AP with an interbody device. METHODS: Patients who underwent a primary 1-level ACDF for degenerative spinal pathology between 2010 and 2013 were analyzed. Patients were stratified on the basis of the type of implant system (SA cage vs. AP) and assessed with regard to demographics, comorbidities, smoking, visual analogue scale (VAS) scores (preoperative/postoperative), procedural time, estimated blood loss (EBL), length of hospitalization, complications, reoperations, narcotic consumption, and total costs. Statistical analysis was performed with independent sample T tests for continuous variables and χ analysis for categorical data. An α level of <0.05 denoted statistical significance. RESULTS: Of the 93 patients included, 52 (55.9%) underwent an ACDF with a SA cage system. Patient demographics, comorbidity burden, body mass index, smoking status, and preoperative VAS score were similar between cohorts. The SA cohort incurred a significantly lower EBL (P<0.001) than the AP cohort. However, none required a transfusion and the procedural time, length of hospitalization, postoperative VAS score, complication rates, 1-year arthrodesis rate, and reoperation rates were similar between cohorts. Postoperative narcotics consumption and total costs were also similar between groups. CONCLUSIONS: Our findings suggest that the SA cage may be associated with a significantly lower EBL, which may not be clinically relevant. Perioperative outcomes, complications, reoperation rates, narcotics consumption in the immediate postoperative period, and total costs may be similar regardless of the instrumentation utilized in a 1-level ACDF.

Neuroforaminal Bone Growth Following Minimally Invasive Transforaminal Lumbar Interbody Fusion With BMP: A Computed Tomographic Analysis.

STUDY DESIGN: Computed tomographic analysis. OBJECTIVE: To identify radiographic patterns of symptomatic neuroforaminal bone growth (NFB) in patients who have undergone a single-level minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) augmented with bone morphogenetic proteins (BMP) utilizing computed tomography (CT). SUMMARY OF BACKGROUND DATA: BMP induces osteoblast differentiation leading to new bone formation. The association of BMP utilization and heterotopic bone formation after an MIS-TLIF has been described. However, studies have been limited in their patient population and details regarding diagnosis and treatment of NFB. MATERIALS AND METHODS: Postoperative CT scans of the symptomatic and asymptomatic patients were analyzed to identify patterns of heterotopic bone growth on axial and sagittal views. The area of bone growth at the disk level, lateral recess, adjacent foramen, and retrovertebral area were measured. Mann-Whitney U test was used to compare the areas of bone growth between cohorts. RESULTS: Postoperative CT images between 18 symptomatic and 13 asymptomatic patients were compared. On axial views, the symptomatic patients demonstrated greater areas of bone growth at the disk level (164.0±92.4 vs. 77.0±104.9 mm), and lateral recess (69.6±70.5 and 5.9±12.5 mm) as well as in the total cross-sectional area (290.3±162.1 vs. 119.4±115.6 mm). On sagittal imaging, the mean bone growth at the subarticular level (148.7±185.1 vs. 35.8±37.4 mm) and the total cross-sectional area (298.4±324.4 vs. 85.8±76.3 mm) were greater in symptomatic patients (P<0.01). Amount of BMP utilized and operative levels were no different between cohorts. CONCLUSIONS: The findings of the present study suggest that an anatomic association exists between recalcitrant postoperative radiculopathy and NFB following an MIS-TLIF with BMP. Increased total bone growth as measured on serial axial and sagittal sections was associated with postoperative radiculopathy. The association between radiculopathy and the extension of BMP-induced bone growth toward the traversing nerve root appeared the most significant.

A Comparison of Implants Used in Open-Door Laminoplasty: Structural Rib Allografts Versus Metallic Miniplates.

STUDY DESIGN: A retrospective case-controlled study. SUMMARY OF BACKGROUND DATA: Open-door laminoplasty has been successfully used to address cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. Two common implants include rib allograft struts and metallic miniplates. OBJECTIVE: The goals of this study were to compare outcomes, complications, and costs associated with these 2 implants. METHODS: A retrospective review was done on 51 patients with allograft struts and 55 patients with miniplates. Primary outcomes were neck visual analog scale (VAS) pain scores and Nurick scores. Secondary outcomes included length of the procedure, estimated blood loss, rates of complications, and the direct costs associated with the surgery and inpatient hospitalization. RESULTS: There were no differences in demographic characteristics, diagnoses, comorbidities, and preoperative outcome scores between the 2 treatment groups. Mean follow-up was 27 months. The postoperative neck VAS scores and Nurick scores improved significantly from baseline to final follow-up for both groups, but there was no difference between the 2 groups. The average length of operation (161 vs. 136 min) and number of foraminotomies (2.7 vs. 1.3) were higher for the allograft group (P=0.007 and 0.0001, respectively). Among the miniplate group, there was no difference in complications but a trend for less neck pain for patients treated without hard collar at final follow-up (1.8 vs. 2.3, P=0.52). The mean direct costs of hospitalization for the miniplate group were 15% higher. CONCLUSIONS: Structural rib allograft struts and metallic miniplates result in similar improvements in pain and functional outcome scores with no difference in the rate of complications in short-term follow-up. Potential benefits of using a plate include shorter procedure length and less need for postoperative immobilization. When costs of bracing and operative time are included, the difference in cost between miniplates and allograft struts is negligible.

Current Trends in Outpatient Spine Surgery.

Because of the increasing pressure to contain health-care-related costs, the number of spinal surgeries performed in the outpatient setting has significantly increased. The higher perioperative efficiency and greater predictability of associated costs offer significant incentives for payers and providers to move surgical procedures into the outpatient setting. Nonetheless, judicious patient selection is advised to optimize outcomes.

Does Greater Body Mass Index Increase the Risk for Revision Procedures Following a Single-Level Minimally Invasive Lumbar Discectomy?

STUDY DESIGN: Retrospective analysis of a prospectively maintained surgical registry. OBJECTIVE: To examine the association between body mass index (BMI) and the risk for undergoing a revision procedure following a single-level minimally invasive (MIS) lumbar discectomy (LD). SUMMARY OF BACKGROUND DATA: Studies conflict as to whether greater BMI contributes to recurrent herniation and the need for revision procedures following LD. Patients and surgeons would benefit from knowing whether greater BMI is a risk factor to guide the decision whether to pursue an operative versus non-operative treatment. METHODS: Patients undergoing a single-level MIS LD were retrospectively identified in our institution's prospectively maintained surgical registry. BMI was categorized as normal weight (<25 kg/m), overweight (25-30 kg/m), obese (30-40 kg/m), or morbidly obese (≥40 kg/m). Multivariate analysis was used to test for association with undergoing a revision procedure during the first 2 postoperative years. The model was demographics, comorbidities, and operative level. RESULTS: A total of 226 patients were identified. Of these, 56 (24.8%) were normal weight, 80 (35.4%) were overweight, 66 (29.2%) were obese, and 24 (10.6%) were morbidly obese. A total of 23 patients (10.2%) underwent a revision procedure in the first 2 postoperative years. The 2-year risk for revision procedure was 1.8% for normal weight patients, 12.5% for overweight patients, 9.1% for obese patients, and 25.0% for morbidly obese patients. In the multivariate-adjusted analysis model, BMI category was independently associated with undergoing a revision procedure (P = 0.038). CONCLUSION: These findings indicate that greater BMI is an independent risk factor for undergoing a revision procedure following a LD. These findings conflict with recent studies that have found no difference between obese and non-obese patients in regards to risk for recurrent herniation and/or revision procedures. Patients with greater BMI undergoing LD should be informed they could have an elevated risk for revision procedures. LEVEL OF EVIDENCE: 4.

Effects of Intraoperative Anesthetic Medications on Postoperative Urinary Retention After Single-Level Lumbar Fusion.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: The aim of the study was to identify medications that may potentially contribute to developing postoperative urinary retention (POUR) after lumbar spinal fusion procedures. SUMMARY OF BACKGROUND DATA: POUR is a concerning event that may occur after routine orthopedic surgery. The relation between intraoperative medications and POUR after lumbar spine surgery has not been well characterized. METHODS: A prospectively maintained database of patients who underwent a primary single-level, minimally invasive transforaminal lumbar interbody fusion between 2009 and 2013 was reviewed. POUR was defined as a bladder scan of 300 mL or higher, the postoperative necessity of a straight catheterization, or a urology consult for urinary retention. The use and dose-response of intraoperative medications between patients with and without POUR were compared. Potential risk factors for developing POUR were analyzed using multivariate analysis. RESULTS: A total of 205 patients were included in the study, 17% of whom experienced POUR (n = 34). Administration of phenylephrine and neostigmine was associated with POUR (phenylephrine: 32.3% vs. 13.8%, P = 0.017; neostigmine: 19.5% vs. 6.5%, P = 0.042). Parametric analysis demonstrated an association of increasing dose of neostigmine with POUR (4.66 vs. 4.22 mg, P = 0.023). Similarly, a nonparametric analysis demonstrated an association of increasing doses of both neostigmine and phenylephrine with POUR (neostigmine: 4.25 vs. 3.16 mg, P = 0.02; phenylephrine: 105.88 vs. 40.64 mg, P = 0.008). CONCLUSION: Approximately 20% of patients may develop POUR after routine lumbar spine surgery. The use of certain intraoperative anesthetics such as phenylephrine and neostigmine is strongly associated with the development of POUR postoperatively. This finding suggests that there may be modifiable anesthetic risk factors to prevent the development of POUR in patients undergoing lumbar spine surgery. Future prospective, controlled studies specifically addressing these findings could lead to improved patient care and decreased healthcare costs. LEVEL OF EVIDENCE: 4.

Incidence and risk factors for pneumonia following anterior cervical decompression and fusion procedures: an ACS-NSQIP study.

BACKGROUND CONTEXT: Postoperative pneumonia has important clinical consequences for both patients and the health-care system. Few studies have examined pneumonia following anterior cervical decompression and fusion (ACDF) procedures. PURPOSE: This study aimed to determine the incidence and risk factors for development of pneumonia following ACDF procedures. STUDY DESIGN/SETTING: A retrospective cohort study of data collected prospectively by the American College of Surgeons National Surgical Quality Improvement Program was carried out. PATIENT SAMPLE: This study comprised 11,353 patients undergoing ACDF procedures during 2011-2013. OUTCOME MEASURES: The primary outcome was diagnosis of pneumonia in the first 30 postoperative days. METHODS: Independent risk factors for the development of pneumonia were identified using multivariate regression. Readmission rates were compared between patients who did and did not develop pneumonia using multivariate regression that adjusted for all demographic, comorbidity, and procedural characteristics. RESULTS: The incidence of pneumonia was 0.45% (95% confidence interval=0.33%-0.57%). In the multivariate analysis, independent risk factors for the development of pneumonia were greater age (p<.001), dependent functional status (relative risk [RR]=5.3, p<.001), chronic obstructive pulmonary disease (RR=4.4, p<.001), and greater operative duration (p=.020). Patients who developed pneumonia following discharge had a higher readmission rate than other patients (72.7% vs. 2.4%, adjusted RR=24.5, p<.001). In total, 10.2% of all readmissions were caused by pneumonia. CONCLUSIONS: Pneumonia occurs in approximately 1 in 200 patients following ACDF procedures. Patients who are older, are functionally dependent, or have chronic obstructive pulmonary disease are at greater risk. These patients should be counseled, monitored, and targeted with preventative interventions accordingly. Greater operative duration is also an independent risk factor. Approximately three in four patients who develop pneumonia following hospitalization for ACDF procedures are readmitted. This elevated readmission rate has implications for bundled payments and hospital performance reports.

Preoperative narcotic utilization: accuracy of patient self-reporting and its association with postoperative narcotic consumption.

OBJECTIVE: Little is known about the accuracy of reporting of preoperative narcotic utilization in spinal surgery. As such, the purpose of this study is to compare postoperative narcotic consumption between preoperative narcotic utilizers who do and do not accurately self-report preoperative utilization. METHODS: Patients who underwent anterior cervical discectomy and fusion, minimally invasive lumbar discectomy, or minimally invasive transforaminal lumbar interbody fusion procedures between 2013 and 2014 were prospectively identified. The accuracy of self-reporting preoperative narcotic consumption was determined utilizing the Illinois Prescription Monitoring Program. Total inpatient narcotic consumption during postoperative Days 0 and 1 was compared according to the demographics and preoperative narcotic reporting accuracy. Similarly, the proportion of patients who continued to be dependent on narcotic medications at each postoperative visit was compared according to the demographics and preoperative narcotic reporting accuracy. RESULTS: A total of 195 patients met the inclusion criteria. Of these, 25% did not use narcotics preoperatively, while 47% and 28% did do so with accurate and inaccurate reporting, respectively. Patients who used narcotics preoperatively were more likely to demonstrate elevated inpatient narcotic consumption (adjusted RR 5.3; 95% CI 1.4-20.1; p = 0.013). However, such patients were no more or less likely to be dependent on narcotic medications at the first (p = 0.618) or second (p = 0.798) postoperative visit. Among patients who used narcotics preoperatively, no differences were demonstrated in terms of inpatient narcotic consumption (p = 0.182) or narcotic dependence following the first (p = 0.982) or second (p = 0.866) postoperative visit according to the self-reported accuracy of preoperative narcotic utilization. The only preoperative factors that were independently associated with elevated inpatient narcotic consumption were workers' compensation status and procedure type. The only preoperative factors that were independently associated with narcotic dependence at the first postoperative visit were female sex, workers' compensation status, and procedure type. The only preoperative factor that was independently associated with narcotic dependence at the second postoperative visit was procedure type. CONCLUSIONS: The findings suggest that determining the actual preoperative narcotic utilization in patients who undergo spine surgery may help optimize postoperative pain management. Approximately 75% of patients used narcotics preoperatively. Patients who used narcotics preoperatively demonstrated significantly higher inpatient narcotic consumption, but this difference did not persist following discharge. Finally, postoperative narcotic consumption (inpatient and following discharge) was independent of the self-reported accuracy of preoperative narcotic utilization. Taken together, these findings suggest that corroboration between the patient's self-reported preoperative narcotic utilization and other sources of information (e.g., family members and narcotic registries) may be clinically valuable with respect to minimizing narcotic requirements, thereby potentially improving the management of postoperative pain.

Anterior corpectomy via the mini-open, extreme lateral, transpsoas approach combined with short-segment posterior fixation for single-level traumatic lumbar burst fractures: analysis of health-related quality of life outcomes and patient satisfaction.

OBJECTIVE: The authors present clinical outcome data and satisfaction of patients who underwent minimally invasive vertebral body corpectomy and cage placement via a mini-open, extreme lateral, transpsoas approach and posterior short-segment instrumentation for lumbar burst fractures. METHODS: Patients with unstable lumbar burst fractures who underwent corpectomy and anterior column reconstruction via a mini-open, extreme lateral, transpsoas approach with short-segment posterior fixation were reviewed retrospectively. Demographic information, operative parameters, perioperative radiographic measurements, and complications were analyzed. Patient-reported outcome instruments (Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12]) and an anterior scar-specific patient satisfaction questionnaire were recorded at the latest follow-up. RESULTS: Twelve patients (7 men, 5 women, average age 42 years, range 22-68 years) met the inclusion criteria. Lumbar corpectomies with anterior column support were performed (L-1, n = 8; L-2, n = 2; L-3, n = 2) and supplemented with short-segment posterior instrumentation (4 open, 8 percutaneous). Four patients had preoperative neurological deficits, all of which improved after surgery. No new neurological complications were noted. The anterior incision on average was 6.4 cm (range 5-8 cm) in length, caused mild pain and disability, and was aesthetically acceptable to the large majority of patients. Three patients required chest tube placement for pleural violation, and 1 patient required reoperation for cage subsidence/hardware failure. Average clinical follow-up was 38 months (range 16-68 months), and average radiographic follow-up was 37 months (range 6-68 months). Preoperative lumbar lordosis and focal lordosis were significantly improved/maintained after surgery. Patients were satisfied with their outcomes, had minimal/moderate disability (average ODI score 20, range 0-52), and had good physical (SF-12 physical component score 41.7% ± 10.4%) and mental health outcomes (SF-12 mental component score 50.2% ± 11.6%) after surgery. CONCLUSIONS: Anterior corpectomy and cage placement via a mini-open, extreme lateral, transpsoas approach supplemented by short-segment posterior instrumentation is a safe, effective alternative to conventional approaches in the treatment of single-level unstable burst fractures and is associated with excellent functional outcomes and patient satisfaction.

Minimally Invasive Posterior Cervical Foraminotomy.

The minimally invasive posterior cervical foraminotomy procedure has become a common and successful procedure for the treatment of cervical radiculopathy. Specifically, the minimally invasive approach allows for decreased postoperative pain, blood loss, and length of hospitalization by preserving the surrounding soft tissue as compared with the traditional open approach. This article and accompanying video demonstrates the technique for a primary, single-level minimally invasive posterior cervical foraminotomy as performed through a tubular retractor.

Quantification of Multifidus Atrophy and Fatty Infiltration Following a Minimally Invasive Microdiscectomy.

BACKGROUND: Multifidus muscle degeneration and atrophy have been demonstrated following traditional open spine surgery. The purpose of this study was to quantify multifidus muscle atrophy and fatty infiltration following a 1-level minimally invasive (MIS) lumbar discectomy. METHODS: Magnetic resonance imaging (MRI) of 24 patients who underwent a primary 1-level MIS microdiscectomy were reviewed. Demographics, operative levels, and time from surgery to imaging were assessed. Total and lean cross-sectional areas (CSA), T1-signal intensity ratio between the multifidus and psoas muscles, and lean-to-total CSA ratio were measured. Pre- and postoperative values were compared within each patient utilizing paired sample T-tests. RESULTS: The mean age was 47.8±14.2 years. MRI was obtained 182.5±194.4 days following index surgery. On the ipsilateral side, total CSA decreased at the index level (-4.9%) and the lean CSA decreased at the index (-6.2%), inferior pedicle (-13.0%), and inferior disc levels (-18.6%). On the contralateral side, no significant decreases in total or lean CSA were demonstrated. T1-signal intensity ratios increased at all levels, but the differences were not statistically significant. The lean-to-total CSA ratio was decreased at the superior disc (-5.2%), inferior pedicle (-8.4%), and inferior disc levels (-17.2%) on the ipsilateral side and at the contralateral inferior disc level (-5.3%). CONCLUSIONS: Primary 1-level MIS discectomy results in minimal short-term atrophy and fatty infiltration of the multifidus at the index level. Total CSA atrophy was mainly confined to the ipsilateral side at the index level. Lean CSA atrophy was observed mainly at and below the index level on the ipsilateral side. Fatty infiltration, as measured by the lean-to-total CSA ratio, ranged 1.2-17.2% on the ipsilateral and 0-5.3% on the contralateral side with greater fat content demonstrated caudally to the surgical level. CLINICAL RELEVANCE: Overall, the majority of the multifidus muscle appears to be radiographically preserved following an MIS lumbar discectomy.

The Impact of Worker's Compensation Claims on Outcomes and Costs Following an Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective matched pair cohort analysis using a prospectively maintained registry. OBJECTIVE: To describe the findings associated with workers' compensation (WC) claimants in regard to surgical outcomes, costs, and reimbursement after a 1- or 2- level anterior cervical discectomy and fusion. SUMMARY OF BACKGROUND DATA: WC patients are perceived to demonstrate poor surgical outcomes and greater health care expenditure than more traditional patients. This study aims to evaluate the perceived differences in financial costs between patients with and without WC insurance. METHODS: A retrospective analysis of 352 patients who underwent a primary 1- or 2- level anterior cervical discectomy and fusion for degenerative spinal etiologies between 2007 and 2013 by a single surgeon was performed. Patients were stratified on the basis of the payer status (WC vs. non-WC). Demographics, Charlson Comorbidity Index scores, smoking status, pre- and postoperative Visual Analogue Scale (VAS) scores, procedural time, estimated blood loss, hospital length of stay, complications, and revisions/reoperations were assessed between cohorts. The 1-year arthrodesis rate was also evaluated via computed tomography. Two cohorts of 30 patients were then matched for the number of fusion levels, smoking, and Charlson Comorbidity Index scores to compare hospital costs and reimbursements. All financial data were reported as a ratio of non-WC to WC payment/charges to protect hospital-sensitive financial data. Statistical analysis was performed using the independent sample t test for continuous variables and χ analysis for categorical data. An α level of less than 0.05 denoted statistical significance. RESULTS: A total of 352 patients were included in this study of which 132 (37.5%) carried WC as the primary payer. The WC cohort was significantly younger (45.2 ± 8.5 vs. 52.9 ± 11.9, P < 0.001) and demonstrated a reduced comorbidity burden (2.3 ± 1.2 vs. 3.4 ± 1.7, P < 0.001) compared with non-WC patients. In addition, the WC cohort consisted of a significantly greater proportion of males, non-Caucasians, and active tobacco users. The preoperative VAS score, number of fusion levels, procedural time, and hospital length of stay did not significantly vary between cohorts. The 6-month VAS scores (3.2 ± 2.9 vs. 2.3 ± 2.4, P < 0.05), pseudarthrosis rates (7.6% vs. 0.9%, P < 0.001), revision/reoperations (12.9% vs. 2.7%, P < 0.001), and smoking rates (29.8% vs. 20.5%, P < 0.05) were significantly increased among WC payers. The difference in the total charges for anterior cervical discectomy and fusion between the WC cohort and the non-WC cohort was not statistically significant. The costs associated with implants, anesthesia, operating room, and in-hospital therapy were comparable between cohorts. The WC cohort was associated with a 282% higher reimbursement rate than the non-WC cohort (P < 0.001). CONCLUSION: The WC cohort demonstrated lower clinical improvement, reduced 1-year arthrodesis rate, and an increased incidence of revision/reoperations when compared with non-WC patients. The greater proportion of smokers and increased occupational demands within the WC cohort may help explain these findings. Reimbursement rates were significantly higher in the WC patients. However, costs to the health care system during the acute hospitalization period (implants, operating room resources, postoperative care, and therapy) were similar between cohorts. LEVEL OF EVIDENCE: 3.

Economic factors in the future delivery of spinal healthcare.

The current trajectory of healthcare-related spending in the United States is unsustainable. Currently, the predominant form of reimbursement is the form of a fee-for-service system in which surgeons are reimbursed for each discrete unit of care provided. This system does factor the cost, quality, or outcomes of service provided. For the purposes of cost containment, the bundled episode reimbursement has gained popularity as a potential alternative to the current fee-for-service system. In the newer model, the spinal surgeon will become increasingly responsible for controlling costs. The bundled payment system will initially offer financial incentives to initiate a meaningful national transition from the fee-for-service model. The difficulty will be ensuring that the services of surgeons continue to be valued past this initiation period. However, greater financial responsibilities will be placed upon the individual surgeon in this new system. Over time, the evolving interests of hospital systems could result in the devaluation of the surgeons' services. Significant cooperation on behalf of all involved healthcare providers will be necessary to ensure that quality of care does not suffer while efforts for cost containment continue.

Minimally Invasive Transforaminal Lumbar Interbody Fusion.

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is performed via tubular dilators thereby preserving the integrity of the paraspinal musculature. The decreased soft tissue disruption in the MIS technique has been associated with significantly decreased blood loss, shorter length of hospitalization, and an expedited return to work while maintaining comparable arthrodesis rates when compared with the open technique particularly in the setting of spondylolisthesis (isthmic and degenerative), recurrent symptomatic disk herniation, spinal stenosis, pseudoarthrosis, iatrogenic instability, and spinal trauma. The purpose of this article and the accompanying video wass to demonstrate the techniques for a primary, single-level MIS TLIF.

Urinary Tract Infection Following Posterior Lumbar Fusion Procedures: An American College of Surgeons National Surgical Quality Improvement Program Study.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To determine the incidence and risk factors for the development of a urinary tract infection (UTI) after a posterior lumbar fusion procedure. SUMMARY OF BACKGROUND DATA: UTI after surgery is common and has important clinical consequences for both patients and the health care system. Few studies have examined UTI after spinal fusion procedures. METHODS: Patients undergoing posterior lumbar fusion procedures during 2011 to 2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Statistical comparisons were made using multivariate regression with adjustment for demographic, comorbidity, and operative characteristics. RESULTS: A total of 10,825 patients met inclusion criteria. The incidence of a UTI was 1.77% (95% confidence interval = 1.52%-2.02%). Independent risk factors for a UTI were greater age (for 50-59 yr, relative risk [RR] = 1.0; 60-69 yr, RR = 2.1; ≥70 yr, RR = 3.5; P < 0.001), female sex (RR = 2.2, P < 0.001), dependent functional status (RR = 2.1, P = 0.010), malnutrition (RR = 2.3, P = 0.004), diabetic status (for non-insulin-dependent diabetes, RR = 1.5; for insulin-dependent diabetes, RR = 1.9; P = 0.011), and increased operative duration (for 120-179  min, RR = 1.4; 180-239  min, RR = 2.3; and for ≥240  min, RR = 2.7; P < 0.001).Patients who developed a UTI had a greater risk for systemic sepsis than other patients (11.5% vs. 0.63%; adjusted RR = 14.4, P < 0.001). Patients who developed a UTI had a greater risk for readmission than other patients (36.7% vs. 5.0%; adjusted RR = 6.1, P < 0.001). CONCLUSION: UTIs occur in nearly 1 in 50 patients undergoing posterior lumbar fusion procedures. Patients who are older, female, dependent, malnourished, or diabetic are at greater risk and should be counseled and monitored accordingly. In addition, morbidity associated with a UTI in this population is substantial, as demonstrated by a 14-fold increase in the risk for systemic sepsis and a 6-fold increase in the risk for readmission. As such, increased preventative measures should be targeted to the patients identified here to be at greatest risk. LEVEL OF EVIDENCE: 3.

BMP-2-induced Neuroforaminal Bone Growth in the Setting of a Minimally Invasive Transforaminal Lumbar Interbody Fusion.

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has become a popular alternative to traditional methods of lumbar decompression and fusion. When compared with the open technique, the minimally invasive approach can result in decreased pain and blood loss as well as a shorter length of hospitalization. However, the narrower working channel through the tubular retractor increases the difficulty of decortication and bone grafting. Therefore, recombinant human bone morphogenetic proteins (rhBMP-2) is often utilized (although this is off-label) to create a more favorable interbody fusion environment. Recently, the use of rhBMP-2 has been associated with excessive bone growth in an MIS-TLIF. If this bone growth compresses the neighboring neural structures, patients may present with either new or recurrent radicular pain. Computed tomographic (CT) imaging can demonstrate heterotopic bone growth extending from the disk space into either the ipsilateral neuroforamen or lateral recess, which may result in the compression of the exiting or traversing root, respectively. The purpose of this article and the accompanying video is to demonstrate a technique for defining and resecting rhBMP-2-induced heterotopic bone growth following a previous MIS-TLIF.