Describing the spine surgery learning curve during the first two years of independent practice.

ABSTRACT: Retrospective cohort studyTo characterize the learning curve of a spine surgeon during the first 2 years of independent practice by comparing to an experienced colleague. To stratify learning curves based on procedure to evaluate the effect of experience on surgical complexity.The learning curve for spine surgery is difficult to quantify, but is useful information for hospital administrators/surgical programs/new graduates, so appropriate expectations and accommodations are considered.Data from a retrospective cohort (2014-2016) were analyzed at a quaternary academic institution servicing a geographically-isolated, mostly rural area. Procedures included anterior cervical discectomy and fusion, posterior cervical decompression and stabilization, single and 2-level posterior lumbar interbody fusion, lumbar discectomy, and laminectomy. Data related to patient demographics, after-hours surgery, and revision surgery were collected. Operative time was the primary outcome measure, with secondary measures including cerebrospinal fluid leak and early re-operation. Time periods were stratified into 6 month quarters (quarter [Q] 1-Q4), with STATA software used for statistical analysis.There were 626 patients meeting inclusion criteria. The senior surgeon had similar operative times throughout the study. The new surgeon demonstrated a decrease in operative time from Q1 to Q4 (158 minutes-119 minutes, P < .05); however, the mean operative time was shorter for the senior surgeon at 2 years (91 minutes, P < .05). The senior surgeon performed more revision surgeries (odds ratio [OR] 2.5 [95% confidence interval [CI] 1.7-3.6]; P < .001). Posterior interbody fusion times remained longer for the new surgeon, while laminectomy surgery was similar to the senior surgeon by 2 years. There were no differences in rates of cerebrospinal fluid leak (OR 1.2 [95% CI 0.6-2.5]; P > .05), nor reoperation (OR 1.16 [95% CI 0.7-1.9]; P > .05) between surgeons.A significant learning curve exists starting spine practice and likely extends beyond the first 2 years for elective operations.

Significance of Hospital Size in Outcomes of Single-Level Elective Anterior Cervical Discectomy and Fusion: A Nationwide Readmissions Database Analysis.

OBJECTIVE: To elucidate risk factors for 90-day readmission in anterior cervical discectomy and fusion (ACDF) for small, medium, and large hospitals. To assess differences in length of stay, charges, and complication rates across hospitals of different size. METHODS: A retrospective analysis was performed using elective, single-level ACDF data from 2016 to 2018 in the Healthcare Cost and Utilization Project Nationwide Readmissions Database. Elective single-level ACDF cases were stratified into 3 groups by hospital bed size (small, medium, and large). All-cause complication rates, mean charges, length of stay, and 90-day readmission rates were compared across hospital size. Frequencies of specific comorbidities were compared between readmitted and nonreadmitted patients for each hospital size. Comorbidities significant on univariate analysis were evaluated as independent risk factors for 90-day readmission for each hospital size using multivariate regression. RESULTS: The overall 90-day readmission rate was 6.43% in 36,794 patients, and the rates for small, medium, and large hospitals were 6.25%, 6.28%, and 6.56%, respectively (P = 0.537). Length of stay increased significantly with hospital size (P < 0.001), and small hospitals had the lowest charges (P < 0.001). Although different independent predictors of 90-day readmission were identified for each hospital size, cardiac arrhythmia, chronic pulmonary disease, neurologic disorders, and rheumatic disease were identified as risk factors for hospitals of all sizes. CONCLUSIONS: Hospital size is a determining factor for charges and length of stay associated with elective single-level ACDF. Variation in risk factors for readmission exists across hospital size in context of similar 90-day readmission rates.

Dose Adjustment Associated Complications of Bone Morphogenetic Protein: A Longitudinal Assessment.

OBJECTIVE: Bone morphogenetic protein (BMP) is a growth factor that aids in osteoinduction and promotes bone fusion. There is a lack of literature regarding recombinant human BMP-2 (rhBMP-2) dosage in different spine surgeries. This study aims to investigate the trends in rhBMP-2 dosage and the associated complications in spinal arthrodesis. METHODS: A retrospective study was conducted investigating spinal arthrodesis using rhBMP-2. Variables including age, procedure type, rhBMP-2 size, complications, and postoperative imaging were collected. Cases were grouped into the following surgical procedures: anterior lumbar interbody fusion/extreme lateral interbody fusion (ALIF/XLIF), posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF), posterolateral fusion (PLF), anterior cervical discectomy and fusion (ACDF), and posterior cervical fusion (PCF). RESULTS: A total of 1209 patients who received rhBMP-2 from 2006 to 2020 were studied. Of these, 230 were categorized as ALIF/XLIF, 336 as PLIF/TLIF, 243 as PLF, 203 as ACDF, and 197 as PCF. PCF (P < 0.001), PLIF/TLIF (P < 0.001), and PLF (P < 0.001) demonstrated a significant decrease in the rhBMP-2 dose used per level, with major transitions seen in 2018, 2011, and 2013, respectively. In our sample, 129 complications following spinal arthrodesis were noted. A significant relation between rhBMP-2 size and complication rates (χ2= 73.73, P = 0.0029) was noted. rhBMP-2 dosage per level was a predictor of complication following spinal arthrodesis (odds ratio = 1.302 [1.05-1.55], P < 0.001). CONCLUSIONS: BMP is an effective compound in fusing adjacent spine segments. However, it carries some regional complications. We demonstrate a decreasing trend in the dose/vertebral level. A decrease rhBMP-2 dose per level correlated with a decrease in complication rates.

Validation of VR-12 Physical Function in Minimally Invasive Lumbar Discectomy.

BACKGROUND: Although the Veterans RAND 12-item Physical Component Survey (VR-12 PCS) has been broadly used to evaluate patient-reported outcome measures (PROMs) in spine surgery, its feasibility for use in patients undergoing minimally invasive lumbar discectomy (MIS LD) has not been well studied. This study aimed to assess the feasibility of VR-12 PCS for use up to 2 years postoperatively for MIS LD by correlation with PROMs for physical function. METHODS: Patients undergoing primary single-level MIS LD procedures were reviewed retrospectively. Results on the VR-12 PCS, 12-Item Short Form (SF-12) PCS, and Patient-Reported Outcomes Measurement Information System (PROMIS PF) were recorded preoperatively and up to 2 years postoperatively. Improvements in postoperative PROMs were calculated and assessed for significant differences from baseline values. Correlation significance and strength were evaluated between VR-12 PCS and SF-12 PCS or PROMIS PF. Scatterplots were constructed to demonstrate relationships of VR-12 PCS with SF-12 PCS and PROMIS PF at each time point. RESULTS: Our cohort comprised 402 patients. Patients improved significantly from preoperative baseline for all 3 PROMs at all postoperative time points. Both Pearson's correlation and time-independent partial correlation revealed statistically significant strong correlations of VR-12 PCS with SF-12 PCS and PROMIS PF through 2-years. DISCUSSION: Physical function scores for VR-12, SF-12, and PROMIS PF all demonstrated significant improvements following MIS LD. Strongly statistically significant correlations of VR-12 PCS with SF-12 PCS and PROMIS PF from preoperative measures through 2 years demonstrate the feasibility of VR-12 for assessing patient-reported physical function in MIS LD patients.

Hospital use following anterior cervical discectomy and fusion.

Most existing anterior cervical discectomy and fusion (ACDF) outcome studies omit emergency department (ED) use. To our knowledge, this study on ED use following ACDF surgery is the first to use a direct patient chart review and the first to include revision patients, 1-5 levels of ACDFs, and performance of corpectomy in the analysis. This study examines the frequency and basis of hospital service use within 30 days of ACDF surgery, specifically ED visits, hospital readmissions, and returns to the operating room. A retrospective chart review was performed for 1273 consecutive patients who underwent ACDF surgery at one institution from July 2013 to June 2016. Of the 1273 patients with ACDF, 97 (7.6%) presented to the ED within 30 days after surgery. Of 43 patients with revision ACDF, 9 (20.9%) returned to the ED, compared with 88 (7.2%) of 1230 patients with primary ACDF (P = 0.001). Of the 111 ED visits by 97 patients, 40 (36%) were for cervicalgia, 13 (12%) were for dysphagia, 8 (7%) were for trauma, 7 (6%) were for nausea, 4 (4%) were for medication refill, 3 (3%) were for dehiscence, 3 (3%) were for pneumonia, and 3 (3%) were for urinary tract infection. Of the ED presentations, 8 (7%) occurred during the first 2 days after surgery, and 46 (41%) occurred within the first postoperative week.

Lumbar disc herniation surgery: Is it worth adding interspinous spacer or instrumented fusion with regard to disc excision alone?

BACKGROUND: Discectomy is sometimes associated with recurrence of disc herniation and pain after surgery. The evidence to use an interspinous dynamic stabilization system or instrumented fusion in association with disc excision to prevent pain and re-operation remains controversial. In this study, we analyzed if adding interspinous spacer or fusion, offers advantages in relation to microdiscetomy alone. METHODS: Patients with lumbar disc herniation were divided in 3 groups; microdiscectomy alone (MD), microdiscectomy plus interspinous spacer (IS) and open discectomy plus posterior lumbar interbody fusion (PLIF). The clinical efficacy was measured using the Owestry Disability Index (ODI). Other outcome parameters including visual analogue scale for pain (VAS) back and legs, length of stay, direct in-hospital cost, 90-day complication rate, and 1-year re-operation rate were also evaluated. RESULTS: A total of 103 patients whose mean age was 39.1 (±8.5) years were included. A significant improvement of the ODI and VAS back and legs pain baseline score was detected in the 3 groups. After 1 year, no significant differences in ODI, VAS back and legs pain were found between the 3 groups. There was an increase of 169% of the total direct in- hospital cost in IS group and 287% in PLIF group, in relation to MD (p < 0.001). Length of stay was 86% higher in the IS group and 384% longer in the PLIF group compared to MD (p < 0.001). The 1 year re-operation rates were 5.6%, 10% and 16.2% (p = 0.33). Discectomy seems to be the main responsible for the clinical improvement, without the interspinous spacer or fusion adding any benefit. The addition of interspinous spacer or fusion increased direct in-hospital cost, length of stay, and did not protect against re-operation.

Decreasing Incidence of Lumbar Discectomy Surgery in Finland in 1997-2018.

STUDY DESIGN: Retrospective register study. OBJECTIVE: The aim of this study was to assess the incidence and trends of lumbar disc surgeries in Finland from 1997 through 2018. SUMMARY OF BACKGROUND DATA: The evidence on lumbar spine discectomy has shifted from supporting surgical treatment toward nonoperative treatment. Still, the incidence of lumbar discectomy operations increased until the 1990 s. In the United States, the incidence began to decline after a downward turn in 2008, yet recent trends from countries with public and practically free health care are not widely known. METHODS: Data for this study were obtained from the Finnish nationwide National Hospital Discharge Register. The study population covered all patients 18 years of age or older in Finland during a 22-year period from January 1, 1997, to December 31, 2018. RESULTS: A total of 65,912 lumbar discectomy operations were performed in Finland from 1997 through 2018. The annual population-based incidence of lumbar discectomy decreased 29% during the 22-year period, from 83 per 100,000 person-years in 1997 to 58 per 100,000 person-years in 2018. In addition, the incidence of microdiscectomy increased 12%, from 41 per 100,000 person-years in 1997 to 47 per 100,000 person-years in 2018, whereas the incidence of open discectomy decreased 71%, from 41 per 100,000 person-years in 1997 to 12 per 100,000 person-years in 2018. The total reoperation rate for microendoscopic, microscopic, and open discectomy surgeries was 16.3%, 15.3%, and 14.9%, respectively. CONCLUSION: The nationwide incidence of lumbar discectomy decreased in Finland from 1997 through 2018. Additionally, the incidence of open discectomy is decreasing rapidly, whereas the incidence of microsurgical techniques is increasing.Level of Evidence: 3.

Evaluation of Benefit and Cost Utility of Immediate Postanesthesia Care Unit Radiographs to Predict Airway Compromise After Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure that may be complicated by airway compromise postoperatively. This life-threatening complication may necessitate reintubation and reoperation. We evaluated the cost utility of conventional postoperative x-ray. SUMMARY OF BACKGROUND DATA: Studies have demonstrated minimal benefit in obtaining an x-ray on postoperative day 1, but there is some utility of postanesthesia care unit (PACU) x-rays for predicting the likelihood of reoperation. METHODS: We retrospectively reviewed the records of consecutive patients who underwent ACDF between September 2013 and February 2017. Patients were dichotomized into those who received PACU x-rays and those who did not (control group). Primary outcomes were reoperation, reintubation, mortality, and health care costs. RESULTS: Eight-hundred and fifteen patients were included in our analysis: 558 had PACU x-rays; 257 did not. In those who received PACU x-rays, mean age was 53.7 ±â€Š11.3 years, mean levels operated on were 2.0 ±â€Š0.79, and mean body mass index (BMI) was 30.3 ±â€Š6.9. In those who did not, mean age was 51.8 ±â€Š10.9 years, mean levels operated on were 1.48 ±â€Š0.65, and mean BMI was 29.9 ±â€Š6.3. Complications in the PACU x-ray group were reintubation-0.4%, reoperation-0.7%, and death-0.3% (due to prevertebral swelling causing airway compromise). Complications in the control group were reintubation-0.4%, reoperation-0.8%, and death-0. There were no differences between groups with respect to reoperation (P = 0.92), reintubation (P = 0.94), or mortality (P = 0.49). The mean per-patient cost was significantly higher (P = 0.009) in those who received PACU x-rays, $1031.76 ±â€Š948.67, versus those in the control group, $700.26 ±â€Š634.48. Mean length of stay was significantly longer in those who had PACU x-rays (P = 0.01). CONCLUSION: Although there were no differences in reoperation, reintubation, or mortality, there was a significantly higher cost for care and hospitalization in those who received PACU x-rays. Further studies are warranted to validate the results of the presented study.Level of Evidence: 3.

Comparison of Two-level Cervical Disc Replacement Versus Two-level Anterior Cervical Discectomy and Fusion in the Outpatient Setting.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to evaluate the safety of two-level cervical disc replacement (CDR) in the outpatient setting. SUMMARY OF BACKGROUND DATA: Despite growing interest in CDR, limited data exist evaluating the safety of two-level CDR in the outpatient setting. METHODS: The National Surgical Quality Improvement Program (NSQIP) database was queried for all two-level anterior cervical discectomy and fusion (ACDF) and CDR procedures between 2015 and 2018. Demographics, comorbidities, and 30-day postoperative complication rates of outpatient two-level CDR were compared to those of inpatient two-level CDR and outpatient two-level ACDF. Radiographic data are not available in the NSQIP. RESULTS: A total of 403 outpatient CDRs were compared to 408 inpatient CDRs and 4134 outpatient ACDFs. Outpatient CDR patients were older and more likely to have pulmonary comorbidities compared to inpatient CDR (P < 0.03). Outpatient CDR patients were less likely to have an American Society of Anesthesiologists class ≥2 and have hypertension compared to outpatient ACDF patients (P < 0.0001). Outpatient CDR had a lower 30-day readmission rate (0.5% vs. 2.5%, P = 0.02) and lower 30-day reoperation rate (0% vs. 1%, P = 0.047) compared to inpatient CDR. Outpatient CDR had a lower readmission rate (0.5% vs. 2.1%, P = 0.03) compared to outpatient ACDF, but there was no difference in reoperation rates between the two procedures (0% vs. 0.8%, P = 0.07). Outpatient CDR had an overall complication rate of 0.2%, inpatient CDR had a complication rate of 0.9%, and outpatient ACDF had a complication rate of 1.3%. These differences were not significant. CONCLUSION: To our knowledge, this is the largest multicenter study examining the safety of two-level outpatient CDR procedures. Outpatient two-level CDR was associated with similarly safe outcomes when compared to inpatient two-level CDR and outpatient two-level ACDF. This suggests that two-level CDR can be performed safely in the outpatient setting.Level of Evidence: 3.

A Historical Review of Endoscopic Spinal Discectomy.

As an essential component of minimally invasive spine surgery, endoscopic spine surgery (ESS) has continuously evolved and has been accepted as a practical procedure by the worldwide spine community. Especially for lumbar disc herniation (LDH), the percutaneous endoscopic or full-endoscopic discectomy technique has been scientifically proven through randomized controlled trials and meta-analyses to be a good alternative to open discectomy. The initial concept of endoscopic spine discectomy was concerned with indirect disc decompression using various instruments such as blind forceps, a nucleotome, laser, radiofrequency coblation, and some chemical agents. The main surgical field has been shifted from the intradiscal space to the epidural space. Precise and selective discectomy for extruded LDH in the epidural space under high-quality endoscopic visualization is now feasible. Furthermore, the medical applications of ESS is broadening to include spinal stenosis, segmental instability, infection, and even intradural lesions. In this review article, I describe the history of endoscopic spine discectomy and decompression techniques, as well as evolution of the paradigm. This history may help indicate the future of practical ESS.

Effect of Topical Steroid on Swallowing Following ACDF: Results of a Prospective Double-Blind Randomized Control Trial.

STUDY DESIGN: Randomized, double-blinded, controlled trial. OBJECTIVE: To investigate the effectiveness of local intraoperative corticosteroids at decreasing the severity of swallowing difficulty following multilevel anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Dysphagia is a common complication after ACDF, and while for most patients the symptoms are mild and transient, some patients can suffer from severe dysphagia resulting in significant postoperative morbidity. Previous studies investigating the local application of corticosteroids are limited. METHODS: This was a prospective, randomized, double-blinded, controlled trial of patients undergoing 2, 3, or 4 level ACDF for radiculopathy and/or myelopathy. Patients undergoing multilevel ACDF were randomized to receive local corticosteroid in the retropharyngeal space or placebo (no steroid). Dysphagia was assessed using validated outcomes including the Eating Assessment Tool-10 (Eat-10) and Swallowing Quality of Life (SWAL-QOL) Questionnaire both preoperatively and at 1 day (POD1), 2 days (POD2), and 1-month postoperatively. RESULTS: One-hundred nine patients had a complete dataset available for analysis. Eat-10 scores were significantly lower in the Steroid group on POD2 (8 vs. 16, P = 0.03) and 1-month postoperatively (2 vs. 5, P = 0.03). A comparison of the individual SWAL-QOL subscale scores demonstrated that patients in the Steroid group had better scores than the Control group in various subscales at all postoperative time points. Significant differences were noted (always in favor of the Steroid group) in 40% of subscales on POD1, 60% of subscales on POD2, and 50% of subscales at 1-month postoperatively. The Control group never had a better SWAL-QOL subscale score at any time point postoperatively. CONCLUSION: Local administration of corticosteroid after multilevel ACDF can decrease postoperative severity and symptomatology of dysphagia during the immediate postoperative period to 1-month postoperatively. The long-term effects of local steroid administration on fusion and other complications will need to be established in future studies.Level of Evidence: 1.

Does the Predominant Pain Location Influence Functional Outcomes, Satisfaction and Return to Work After Anterior Cervical Discectomy and Fusion for Cervical Radiculopathy?

STUDY DESIGN: Retrospective review of prospectively-collected registry data. OBJECTIVES: The aim of this study was to determine how different combinations of preoperative neck pain (NP) and arm pain (AP) influence functional outcomes, patient satisfaction, and return-to-work in patients undergoing anterior cervical discectomy and fusion (ACDF) for degenerative cervical radiculopathy (DCR). SUMMARY OF BACKGROUND DATA: Surgeons often base decisions on the traditional belief that the predominance of radicular upper extremity symptoms is a stronger indication for cervical spine surgery than axial pain. However, there is a paucity of literature supporting this notion. METHODS: A prospectively maintained registry was reviewed for all patients who underwent primary ACDF for DCR. Patients were categorized into three groups depending on predominant pain location: AP predominant ([APP]; AP > NP), NP predominant ([NPP]; NP > AP), and equal pain predominance ([EPP]; NP = AP). Patients were prospectively followed for at least 2 years. RESULTS: In total, 303 patients were included: 27.4% APP, 38.9% NPP, and 33.7% EPP cases. The APP group was significantly older (P = 0.030), although there were no other preoperative differences among the three groups. After adjusting for baseline differences, the SF-36 Physical Component Summary was significantly better in the APP group at 6 months (P = 0.048) and 2 years (P = 0.039). In addition, they showed a trend towards better 6-month Neck Disability Index (P = 0.077) and 2-year SF-36 Mental Component Summary (P = 0.059). However, an equal proportion of patients in each group achieved the Minimal Clinically Important Difference for each outcome, were satisfied, and returned to work 2 years after surgery. CONCLUSION: Although patients with NPP had slightly poorer function and quality of life, all patients experienced a clinically meaningful improvement in patient-reported outcomes, regardless of the predominant pain location. High rates of satisfaction and return-to-work were also achieved. In the context of proper indications, these findings suggest that ACDF can be equally effective for DCR patients with varying combinations of NP or AP.Level of Evidence: 3.

Do Markers of Inflammation and/or Muscle Regeneration in Lumbar Multifidus Muscle and Fat Differ Between Individuals with Good or Poor Outcome Following Microdiscectomy for Lumbar Disc Herniation?

STUDY DESIGN: Observational study. OBJECTIVE: The aim of this study was to evaluate whether inflammatory and/or muscle regeneration markers in paraspinal tissues (multifidus muscle/fat) during microdiscectomy surgery in patients with lumbar disc herniation (LDH) with radiculopathy, differ between individuals with good or poor outcome. SUMMARY OF BACKGROUND DATA: Structural back muscle changes, including fat infiltration, muscle atrophy, and fiber changes, are ubiquitous with LBP and are thought to be regulated by inflammatory and regeneration processes. Muscle changes might be relevant for recovery after microdiscectomy, but a link between expression of inflammatory and muscle regeneration genes in paraspinal tissues and clinical outcome has not been tested. METHOD: Paraspinal tissues from deep multifidus muscles and fat (intramuscular, sub-cutaneous, epidural) were harvested from twenty-one patients with LDH undergoing microdiscectomy surgery. Quantitative polymerase chain reaction (qPCR) measured expression of 10 genes. Outcome was defined as good (visual analogue scale (VAS) low back pain (LBP)+) or poor (VAS LBP-) by an improvement of >33% or ≤33% on the pain VAS, respectively. Good functional improvement was defined as 25% improvement on the physical functioning scale (PFS). RESULTS: Brain-derived neurotrophic factor expression in deep multifidus was 91% lower (P = 0.014) in the VAS LBP- than VAS LBP+ group. Expression of interleukin-1ß in subcutaneous fat was 48% higher (P = 0.026) in the VAS LBP- than VAS LBP+ group. No markers differed based on PFS. CONCLUSION: Results show a relationship between impaired muscle regeneration profile in multifidus muscle and poor outcome following microdiscectomy for LDH. Inflammatory dysregulation in subcutaneous fat overlying the back region might predict poor surgical outcome.Level of Evidence: 4.

Predictors of Readmission and Prolonged Length of Stay After Cervical Disc Arthroplasty.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of the study was to assess which factors increase risk of readmission within 30 days of surgery or prolonged length of stay (LOS) (≥2 days) after cervical disc arthroplasty (CDA). SUMMARY OF BACKGROUND DATA: Several studies have shown noninferiority at mid- and long-term outcomes after cervical disc arthroplasty (CDA) compared to anterior cervical discectomy and fusion ACDF, but few have evaluated short-term outcomes regarding risk of readmission or prolonged LOS after surgery. METHODS: Demographics, comorbidities, operative details, postoperative complications, and perioperative outcomes were collected for patients undergoing single level CDA in the National Surgical Quality Improvement Program (NSQIP) database. Patients with prolonged LOS, defined as >2 days, and readmission within 30 days following CDA were identified. Univariable and multivariable logistic regression models were used to identify risk factors for prolonged LOS and readmission. RESULTS: A total of 3221 patients underwent single level CDA. Average age was 45.6 years (range 19-82) and 53% of patients were male. A total of 472 (14.7%) experienced a prolonged LOS and 36 (1.1%) patients were readmitted within 30 days following surgery. Predictors of readmission were postoperative superficial wound infection (odds ratio [OR] = 73.83, P < 0.001), American Society of Anesthesiologists (ASA) classification (OR = 1.98, P = 0.048), and body mass index (BMI) (OR = 1.06, P = 0.02). Female sex (OR = 1.76, P < 0.001), diabetes (OR = 1.50, P = 0.024), postoperative wound dehiscence (OR = 13.11, P = 0.042), ASA class (OR = 1.43, P < 0.01), and operative time (OR = 1.01, P < 0.001) were significantly associated with prolonged LOS. CONCLUSION: From a nationwide database analysis of 3221 patients, wound complications are predictors of both prolonged LOS and readmission. Patient comorbidities, including diabetes, higher ASA classification, female sex, and higher BMI also increased risk of prolonged LOS or readmission.Level of Evidence: 3.

Factors Associated With Progression to Surgical Intervention for Lumbar Disc Herniation in the Military Health System.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To determine surgery-free survival of patients receiving conservative management of lumbar disc herniation (LDH) in the military healthcare system (MHS) and risk factors for surgical intervention. SUMMARY OF BACKGROUND DATA: Radiculopathy from LDH is a major cause of morbidity and cost. METHODS: The Military Data Repository was queried for all patients diagnosed with LDH from FY2011-2018; the earliest such diagnosis in a military treatment facility (MTF) was kept for each patient as the initial diagnosis. Follow-up time to surgical intervention was defined as the time from diagnosis to first encounter for lumbar microdiscectomy or lumbar decompression in either a MTF or in the civilian sector. The Military Data Repository was also queried for history of tobacco use at any time during MHS care, age at the time of diagnosis, sex, MHS beneficiary category, and diagnosing facility characteristics. Multivariable Cox proportional hazards models were used to evaluate the associations of patient and diagnosing facility characteristics with time to surgical intervention. RESULTS: A total of 84,985 MHS beneficiaries including 62,771 active duty service members were diagnosed with LDH in a MTF during the 8-year study period. A total of 10,532 (12.4%) MHS beneficiaries, including 7650 (10.9%) active duty, failed conservative management onto surgical intervention with lumbar microdiscectomy or lumbar decompression. Median follow-up time of the cohort was 5.2 (interquartile range 2.6, 7.5) years. Among all healthcare beneficiaries, several patient-level (younger age, male sex, and history of tobacco use) and facility-level characteristics (hospital vs. clinic and surgical care vs. primary care clinic) were independently associated with higher risk of surgical intervention. CONCLUSION: LDH compromises military readiness and negatively impacts healthcare costs. MHS beneficiaries with LDH have a good prognosis with approximately 88% of patients successfully completing conservative management. However, strategies to improve outcomes of conservative management in LDH should address risks associated with both patient and facility characteristics.Level of Evidence: 4.

Is There a Relationship Between Bony Fusion After Anterior Cervical Discectomy and Fusion and Heterotopic Ossification After Cervical Disc Arthroplasty in Hybrid Surgery?

STUDY DESIGN: Retrospective analysis. OBJECTIVE: The aim of this study was to investigate the relationship between bony fusion after anterior cervical discectomy and fusion (ACDF) and heterotopic ossification (HO) after cervical disc arthroplasty (CDA) in hybrid surgery (HS). SUMMARY OF BACKGROUND DATA: The mechanism of postoperative bone formation still remains unknown. It is considered a risk factor in CDA but is essential for a solid union in ACDF. With HS, we could directly study the mechanism and relationship of different forms of postoperative bone formation. METHODS: Clinical data of 91 patients who had undergone consecutive two-level HS between January 2011 and January 2018 and with a minimum of 2-year follow-up was analyzed. HO was assessed based on McAfee's classifications, whereas fusion success was evaluated according the Food and Drug Administration approved criteria. Clinical outcomes and radiographic parameters were collected and used for the relevant comparisons. RESULTS: HO was identified in 48.4% of patients (44/91). The fusion rates of patients in the HO group and the non-HO group at 3, 6, and 12 months postoperatively, and the final follow-up were 81.8% and 19.1%, 95.4% and 74.5%, 95.4% and 85.1%, and 97.7% and 93.6%, respectively. The fusion rates were significantly higher at 3 and 6 months after operation in the HO group than in the non-HO group (P < 0.05). Patients in both groups had significant improvements across all clinical outcomes at final follow-up. CONCLUSION: There was a significant relationship between bony fusion and occurrence of HO after HS, suggesting that both bony fusion and HO are reflections of individual osteogenic capacity. However, a reliable predictor of postoperative bone formation is needed in the future to guarantee a solid bony fusion after ACDF and to further take full advantage of the motion-preserving from CDA. LEVEL OF EVIDENCE: 3.

Disparities in inpatient costs and outcomes after elective anterior cervical discectomy and fusion at safety-net hospitals.

INTRODUCTION: Characterizing disparities that exist at safety-net hospitals is crucial for crafting national healthcare reform policies. Healthcare disparities in performing elective neurosurgical procedures like anterior cervical discectomy and fusion (ACDF) at safety-net hospitals have not yet been examined. OBJECTIVE: We use the National Inpatient Sample (NIS), a national all-payer healthcare database of inpatient admissions, to determine whether safety-net hospitals can provide equitable care after elective ACDF. METHODS: The NIS from 2002 to 2011 was queried for patients who received ACDF in the context of degenerative spine disease. Hospital safety-net burden was designated as low (LBH), medium (MBH), or high (HBH) based on the proportion of inpatient admissions that were billed as Medicaid, self-pay, or charity care. Significance was set at p < 0.001. RESULTS: A total of 219,433 admissions were included in this analysis. HBHs were more likely than LBHs to treat patients who were Black, Hispanic, on Medicaid, or had myelopathy (p < 0.001). After adjusting for patient, hospital, and clinical factors, treatment at an HBH was associated with greater in-patient inflation-adjusted log cost (p < 0.001), but not with greater length of stay (LOS) (p = 0.04) or odds of an inpatient adverse event like death, incidental durotomy, surgical site infections, deep vein thromboses and others (OR 95 % CI = 0.86-1.42, p = 0.43) compared to LBHs. DISCUSSION: Safety net hospitals had greater inpatient costs, but no greater LOS or odds of inpatient adverse events after elective ACDF. These results demonstrate a need for policies that reduce the cost of performing ACDFs at SNHs.

Association Between Physician Industry Payments and Cost of Anterior Cervical Discectomy and Fusion in Medicare Beneficiaries.

BACKGROUND: Neurosurgical spine specialists receive considerable amounts of industry support that may impact the cost of care. The aim of this study was to evaluate the association between industry payments received by spine surgeons and the total hospital and operating room (OR) costs of an anterior cervical discectomy and fusion (ACDF) procedure among Medicare beneficiaries. METHODS: All ACDF cases were identified among the Medicare carrier files from January 1, 2013, to December 31, 2014, and matched to the Medicare inpatient baseline file. The total hospital and OR charges were obtained for these cases. Charges were converted to cost using year-specific cost-to-charge ratios. Surgeons were identified among the Open Payments database, which is used to quantify industry support. Analyses were performed to examine the association between industry payments received and ACDF costs. RESULTS: Matching resulting in the inclusion of 2209 ACDF claims from 2013-2014. In 2013 and 2014, the mean total cost for an ACDF was $21,798 and $21,008, respectively; mean OR cost was $5878 and $6064, respectively. Mann-Whitney U test demonstrated no significant differences in the mean total or OR cost for an ACDF based on quartile of general industry payment received (P = 0.21 and P = 0.54), and linear regression found no association between industry general payments, research support, or investments on the total hospital cost (P = 0.41, P = 0.13, and P = 0.25, respectively), or OR cost for an ACDF (P = 0.35, P = 0.24, and P = 0.40, respectively). CONCLUSIONS: This study suggests that spine surgeons performing ACDF surgeries may receive industry support without impacting the cost of care.

The Outcomes of Patients With Neck Pain Following ACDF: A Comparison of Patients With Radiculopathy, Myelopathy, or Mixed Symptomatology.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The goal of the present study was to determine whether neck pain responds differently to anterior cervical discectomy and fusion (ACDF) between patients with cervical radiculopathy and/or cervical myelopathy. SUMMARY OF BACKGROUND DATA: Many patients who undergo ACDF because of radiculopathy/myelopathy also complain of neck pain. However, no studies have compared the response of significant neck pain to ACDF. METHODS: Patients undergoing one to three-level primary ACDF for radiculopathy and/or myelopathy with significant (Visual Analogue Scale [VAS] ≥ 3) neck pain and a minimum of 1-year follow-up were included. Based on preoperative symptoms patients were split into groups for analysis: radiculopathy (R group), myelopathy (M group), or both (MR group). Groups were compared for differences in Health Related Quality of Life outcomes: Physical Component Score-12, Mental Component Score (MCS)-12, Neck Disability Index, VAS neck, and VAS arm pain. RESULTS: Two hundred thirty-five patients met inclusion criteria. There were 117 patients in the R group, 53 in the M group, and 65 in the MR group. Preoperative VAS neck pain was found to be significantly higher in the R group versus M group (6.5 vs. 5.5; P = 0.046). Postoperatively, all cohorts experienced significant (P < 0.001) reduction in VAS neck pain, (ΔVAS neck; R group: -2.9, M: -2.5, MR: -2.5) with no significant differences between groups. However, myelopathic patients showed greater improvement in absolute MCS-12 scores (P = 0.011), RR (P = 0.006), and % minimum clinically important difference (P = 0.013) when compared with radiculopathy patients. This greater improvement remained following regression analysis (P = 0.025). CONCLUSION: Patients with substantial preoperative neck pain experienced significant reduction in their neck pain, disability, and physical function following ACDF, whether treated for radiculopathy or myelopathy. However, in this study, only myelopathy patients had significant improvements in their mental function as represented by MCS improvements. LEVEL OF EVIDENCE: 3.

Current and Future of Endoscopic Spine Surgery: What are the Common Procedures we Have Now and What Lies Ahead?

The aging population around the world leads to increasing incidence of degenerative spinal conditions. There is a need for a minimally invasive technique in treatment for spinal conditions to meet the medical complexity and comorbidities that comes with aging. Principles of endoscopy are similar to minimally invasive surgery, which is to decrease pressure on soft tissue crushing from prolonged retraction, avoid soft tissue stripping and dissection, and bone and ligamentous preservation for optimal decompression without excessive destruction. Endoscopic spine surgery techniques started slowly in development in the 1970s to 2000s, with a rapid phase of development since the turn of the 21st century with endoscopic solutions developing in cervical, thoracic, and lumbar conditions with increasing complexity in nature of operation. Technological enhancement with progressively supportive literature is pushing boundaries of endoscopy from the early days of soft tissue procedure to current fusion procedures, endoscopic spine surgery techniques is covering more areas of spine than ever previously possible with good clinical results. We present a review on the current techniques available and postulated near future development for endoscopic spine surgery.