Factors Related to Clinical Performance in Spine Surgery Fellowship: Can We Predict Success.

INTRODUCTION: The factors most important in the spine fellowship match may not ultimately correlate with quality of performance during fellowship. This study examined the spine fellow applicant metrics correlated with high application rank compared with the metrics associated with the strongest clinical performance during fellowship. METHODS: Spine fellow applications at three academic institutions were retrieved from the San Francisco Match database (first available to 2021) and deidentified for application review. Application metrics pertaining to research, academics, education, extracurriculars, leadership, examinations, career interests, and letter of recommendations were extracted. Attending spine surgeons involved in spine fellow selection at their institutions were sent a survey to rank (1) fellow applicants based on their perceived candidacy and (2) the strength of performance of their previous fellows. Pearson correlation assessed the associations of application metrics with theoretical fellow rank and actual performance. RESULTS: A total of 37 spine fellow applications were included (Institution A: 15, Institution B: 12, Institution C: 10), rated by 14 spine surgeons (Institution A: 6, Institution B: 4, Institution C: 4). Theoretical fellow rank demonstrated a moderate positive association with overall research, residency program rank, recommendation writer H-index, US Medical Licensing Examination (USMLE) scores, and journal reviewer positions. Actual fellow performance demonstrated a moderate positive association with residency program rank, recommendation writer H-index, USMLE scores, and journal reviewer positions. Linear regressions identified journal reviewer positions (ß = 1.73, P = 0.002), Step 1 (ß = 0.09, P = 0.010) and Step 3 (ß = 0.10, P = 0.002) scores, recommendation writer H-index (ß = 0.06, P = 0.029, and ß = 0.07, P = 0.006), and overall research (ß = 0.01, P = 0.005) as predictors of theoretical rank. Recommendation writer H-index (ß = 0.21, P = 0.030) and Alpha Omega Alpha achievement (ß = 6.88, P = 0.021) predicted actual performance. CONCLUSION: Residency program reputation, USMLE scores, and a recommendation from an established spine surgeon were important in application review and performance during fellowship. Research productivity, although important during application review, was not predictive of fellow performance. LEVEL OF EVIDENCE: III. STUDY DESIGN: Cohort Study.

Response to Preoperative Steroid Injections Predicts Surgical Outcomes in Patients Undergoing Fusion for Isthmic Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The decision to pursue operative intervention for patients with isthmic spondylolisthesis is complex. Although steroid injections are a well-accepted therapeutic modality that may delay or obviate surgery, little is known regarding their ability to predict surgical outcomes. SUMMARY OF BACKGROUND DATA: Here, we examine whether improvement after preoperative steroid injections can accurately predict clinical outcomes after surgery. METHODS: A retrospective cohort analysis was performed on adult patients undergoing primary posterolateral lumbar fusion for isthmic spondylolisthesis between 2013 and 2021. Data were stratified into a control (no preoperative injection) group and an injection group (received a preoperative diagnostic and therapeutic injection). We collected demographic data, peri-injection visual analog pain scores (VAS) pain scores, PROMIS pain interference and physical function scores, Oswestry Disability Index, and VAS pain (back and leg). Student t test was utilized to compare baseline group characteristics. Linear regression was performed comparing changes in peri-injection VAS pain scores and postoperative measures. RESULTS: Seventy-three patients did not receive a preoperative injection and were included in the control group. Fifty-nine patients were included in the injection group. Of patients who received an injection, 73% had >50% relief of their preinjection VAS pain score. Linear regression revealed a positive interaction between the injection efficacy and postoperative pain relief as measured by VAS leg scores ( P <0.05). There was also an association between injection efficacy and back pain relief, though this did not achieve statistical significance ( P =0.068). No association was found between injection efficacy and improvement in Oswestry Disability Index or PROMIS measures. CONCLUSIONS: Steroid injections are often utilized in the nonoperative therapeutic management of patients with lumbar spine disease. Here, we demonstrate the diagnostic value of steroid injections in predicting postoperative leg pain relief in patients undergoing posterolateral fusion for isthmic spondylolisthesis.

Hypoalbuminemia as a Predictor of Mortality, Disability, and Readmission in Patients Undergoing Spine Surgery: A Retrospective Analysis.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The objective of this study was to clarify the association between preoperative albumin status and mortality and morbidity in lumbar spine surgery. SUMMARY OF BACKGROUND DATA: Hypoalbuminemia is a known marker of inflammation and is associated with frailty. Hypoalbuminemia is an identified risk factor for mortality following spine surgery for metastases, yet has not been well studied among spine surgical cohorts outside of metastatic cancer. MATERIALS AND METHODS: We identified patients with preoperative serum albumin laboratory values who underwent lumbar spine surgery at a US public university health system between 2014 and 2021. Demographic, comorbidity, and mortality data were collected along with preoperative and postoperative Oswestry Disability Index (ODI) scores. Any cause readmission within 1 year of surgery was recorded. Hypoalbuminemia was defined as <3.5 g/dL in serum. We examined the Kaplan-Meier survival plots based on serum albumin. Multivariable regression models were used to identify the association between preoperative hypoalbuminemia with mortality, readmission, and ODI, while controlling for age, sex, race, ethnicity, procedure, and Charlson Comorbidity Index. RESULTS: Of 2573 patients, 79 were identified as hypoalbuminemic. Hypoalbuminemic patients had a significantly greater adjusted risk of mortality through 1 year (odds ratio=10.2; 95% CI: 3.1-33.5; P <0.001), and 7 years (hazard ratio=4.18; 95% CI: 2.29-7.65; P <0.001). Hypoalbuminemic patients had ODI scores 13.5 points higher (95% CI: 5.7-21.4; P <0.001) at baseline. Adjusted readmission rates were not different between groups through 1 year (odds ratio=1.15; 95% CI: 0.5-2.62; P =0.75) or through full surveillance (hazard ratio=0.82; 95% CI: 0.44-1.54; P =0.54). CONCLUSIONS: Preoperative hypoalbuminemia was strongly associated with postoperative mortality. Hypoalbuminemic patients did not have demonstrably worse outcomes in their functional disability beyond 6 months. Within the first 6 months following surgery, the hypoalbuminemic group improved at a similar rate to the normoalbuminemic group despite having a greater preoperative disability. However, causal inference is limited in this retrospective study.

Preoperative Fluoroscopically Guided Regional Erector Spinae Plane Blocks Reduce Opioid Use, Increase Mobilization, and Reduce Length of Stay Following Lumbar Spine Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine the effectiveness of erector spinae plane (ESP) blocks at improving perioperative pain control and function following lumbar spine fusions. METHODS: A retrospective analysis was performed on patients undergoing < 3 level posterolateral lumbar fusions. Data was stratified into a control group and a block group. We collected postop MED (morphine equivalent dosages), physical therapy ambulation, and length of stay. PROMIS pain interference (PI) and physical function (PF) scores, ODI, and VAS were collected preop and at the first postop visit. Chi-square and student's t-test (P = .05) were used for analysis. We also validated a novel fluoroscopic technique for ESP block delivery. RESULTS: There were 37 in the block group and 39 in the control group. There was no difference in preoperative opioid use (P = .22). On postop day 1, MED was reduced in the block group (32 vs 51, P < .05), and more patients in the block group did not utilize any opioids (22% vs 5%, P < .05). The block group ambulated further on postop day 1 (312 ft vs 204 ft, P < .05), and had reduced length of stay (2.4 vs 3.2 days, P < .05). The block group showed better PROMIS PI scores postoperatively (58 vs 63, P < .05). The novel delivery technique was validated and successful in targeting the correct level and plane. CONCLUSIONS: ESP blocks significantly reduced postop opioid use following lumbar fusion. Block patients ambulated further with PT, had reduced length of stay, and had improved PROMIS PI postoperatively. Validation of the block demonstrated the effectiveness of a novel fluoroscopic delivery technique. ESP blocks represent an underutilized method of reducing opioid consumption, improving postoperative mobilization and reducing length of stay following lumbar spine fusion.

Risk Factors for Postoperative Ileus in Patients Undergoing Spine Surgery.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: Postoperative ileus (POI) is a common complication following elective spinal surgeries. The aim of this study was to determine the incidence of POI and identify demographic and surgical risk factors for developing POI after elective instrumented fusion of the thoracolumbar spine. METHODS: The University of Utah Institutional Review Board (IRB) approved this retrospective study. The study does not require informed consent given the data reviewed was deidentified and collected in accordance with the institution's standard of care. A designated IRB committee determined that study is exempt under exemption category 7. IRB approval number 00069703. Patients undergoing instrumented thoracolumbar fusion for one or more levels were retrospectively identified from an internal spine surgery database. Cases performed for trauma, infection, or tumors were excluded. Demographics, medical comorbidities, surgical variables, and opioid medication administration (morphine milligram equivalents, MME) were abstracted from the electronic medical record. Univariate analysis was used to identify variables associated with POI. These variables were then tested for independent association with POI using multivariate logistic regression. RESULTS: 418 patients were included in the current study. The incidence of POI was 9.3% in this cohort. There was no significant relationship between development of POI and patient age, gender, BMI, diabetes mellitus, thyroid dysfunction, lung disease, CKD, GERD, smoking status, alcohol abuse, anemia, or prior abdominal surgery. Univariate analysis demonstrated significant association between POI and fusion ≥7 levels compared to fusions of fewer levels (P = .001), as well as intraoperative sufentanil compared to other opioids (35.9% vs 20.1%, P = .02). POI was not significantly associated with total intraoperative MME, approach, use of interbody cage, or osteotomy. Multivariate logistic regression confirmed total 24-hour postoperative MME as an independent risk factor for POI (OR 1.004, P = .04), however, intraoperative sufentanil administration was not an independent risk factor for POI when controlling for other variables. CONCLUSIONS: This retrospective cohort study demonstrates that greater postoperative MME is an independent risk factor for POI after thoracolumbar spine fusion when accounting for demographic, medical, and surgical variables with multiple logistic regression. Prospective studies are warranted to evaluate clinical measures to decrease the risk of POI among patients undergoing instrumented thoracolumbar spinal fusions.

Considerations for Lumbar Medial Branch Nerve Radiofrequency at Spinal Motion Segments Adjacent to a Fusion Construct.

Instrumented lumbar spinal fusion is common and results in biomechanical changes at adjacent spinal segments that increase facet load bearing. This can cause facet-mediated pain at levels adjacent to the surgical construct. Medial branch nerve radiofrequency ablation (RFA) exists as a treatment for some cases. It is important to acknowledge that the approach and instrumentation used during some specific lumbar fusion approaches will disrupt the medial branch nerve(s). Thus, the proceduralist must consider the fusion approach when determining which medial branch nerves are necessary to anesthetize for diagnosis and then to potentially target with RFA. This article discusses the relevant technical considerations for preparing for RFA to denervate lumbosacral facet joints adjacent to fusion constructs.

What Does Your PROMIS Score Mean? Improving the Utility of Patient-Reported Outcomes at the Point of Care.

STUDY DESIGN: Prospective cohort. OBJECTIVES: Patient-Reported Outcome Measurement Information System (PROMIS) has been validated for lumbar spine. Use of patient-reported outcome (PRO) measures can improve clinical decision making and health literacy at the point of care. Use of PROMIS, however, has been limited in part because clinicians and patients lack plain language understanding of the meaning of scores and it remains unclear how best to use them at the point of care. The purpose was to develop plain language descriptions to apply to PROMIS Physical Function (PF) and Pain Interference (PI) scores and to assess patient understanding and preferences in presentation of their individualized PRO information. METHODS: Retrospective analysis of prospectively collected PROMIS PF v1.2 and PI v1.1 for patients presenting to a tertiary spine center for back/lower extremity complaints was performed. Patients with missing scores, standard error >0.32, and assessments with <4 or >12 questions were excluded. Scores were categorized into score groups, specifically PROMIS PF groups were: <18, 20 ± 2, 25 ± 2, 30 ± 2, 35 ± 2, 40 ± 2, 45 ± 2, 50 ± 2, 55 ± 2, 60 ± 2, and >62; and PROMIS PI groups were: <48, 50 ± 2, 55 ± 2, 60 ± 2, 65 ± 2, 70 ± 2, 75 ± 2, 80 ± 2, and >82. Representative questions and answers from the PROMIS PI and PROMIS PF were selected for each score group, where questions with <25 assessments or representing <15% of assessments were excluded. Two fellowship-trained spine surgeons further trimmed the questions to create a streamlined clinical tool using a consensus process. Plain language descriptions for PROMIS PF were then used in a prospective assessment of 100 consecutive patients. Patient preference for consuming the score data was recorded and analyzed. RESULTS: In total, 12 712 assessments/5524 unique patients were included for PF and 14 823 assessments/6582 unique patients for PI. More than 90% of assessments were completed in 4 questions. The number of assessments and patients per scoring group were normally distributed. The mean PF score was 37.2 ± 8.2 and the mean PI was 63.3 ± 7.4. Plain language descriptions and compact clinical tool was were generated. Prospectively 100 consecutive patients were surveyed for their preference in receiving their T-score versus plain language description versus graphical presentation. A total of 78% of patients found receiving personalized PRO data helpful, while only 1% found this specifically not helpful. Overall, 80% of patients found either graphical or plain language more helpful than T-score alone, and half of these preferred plain language and graphical descriptions together. In total, 89% of patients found the plain language descriptions to be accurate. CONCLUSIONS: Patients at the point of care are interested in receiving the results of their PRO measures. Plain language descriptions of PROMIS scores enhance patient understanding of PROMIS numerical scores. Patients preferred plain language and/or graphical representation rather than a numerical score alone. While PROs are commonly used for assessing outcomes in research, use at point of care is a growing interest and this study clarifies how they might be utilized in physician-patient communication.

Cost analysis of primary single-level lumbar discectomies using the Value Driven Outcomes database in a large academic center.

BACKGROUND CONTEXT: Improving value is an established point of emphasis to reduce the rapidly rising health care costs in the United States. Back pain is a major driver of costs with a substantial fraction caused by lumbar radiculopathy. The most common surgical treatment for lumbar radiculopathy is microdiscectomy. Research is sparse regarding variables driving cost in microdiscectomies and often limited by cost data derived from payer-based Medicare data. PURPOSE: To identify targets for cost reduction by determining variables associated with significant cost variation in microdiscectomies, using cost data derived from the Value Driven Outcomes tool and actual system costs. STUDY DESIGN: Single-center, retrospective study of prospectively collected registry data. PATIENT SAMPLE: Six hundred twenty-two patients identified by CPT code and manually screened for initial, unilateral, single-level lumbar discectomy performed between 2014 and 2018 at a single institution. OUTCOME MEASURES: Primary outcome measures include total direct cost, clinical length of stay, and OR minutes. Total Direct Cost was further differentiated into facility and nonfacility costs. METHODS: Univariate and multivariate generalized linear models (GLM) were used to identify variables associated with variation in primary outcome measures. Costs were normalized by mean cost for patients with normal body mass index (BMI) and a healthy American Society of Anesthesiologists (ASA) classification. Average marginal effects were reported as percentage of normalized costs. RESULTS: Advanced age, male gender, Hispanic, black, unemployment, obesity, higher ASA class, insurance status, and being retired were positively associated with costs in univariate analysis. Asian, Native American, outpatient procedures, and being a student were associated with decreases in costs. In multivariate analysis, we found that obesity led to higher average marginal total direct (9%), total facility (15%), and facility OR costs (22%), as well as 24 more OR minutes per surgery. While being overweight was not associated with greater total direct costs, it was associated with higher total facility (8%), and facility OR costs (12%), with 11 more OR minutes per surgery. Age was associated with a longer LOS but not with OR costs. As expected, outpatient surgical costs, LOS, and OR time were significantly lower than inpatient procedures. Severe systematic disease was associated with greater total and nonfacility costs. In addition, Medicare patients had higher facility costs (14%) compared to privately insured patients. CONCLUSIONS: Significant drivers of total direct cost in multivariate GLM analysis were obesity, severe systemic disease and inpatient surgery. Average LOS was increased due to age and inpatient status, conversely it was decreased by unemployment and retirement. Significant variables in OR time were male sex, Hispanic race and both obese and overweight BMIs.

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.

Biomechanical effects of laminectomies in the human lumbar spine: a finite element study.

BACKGROUND CONTEXT: Previous studies have analyzed the effect of laminectomy on intervertebral disc (IVD), facet-joint-forces (FJF), and range of motion (ROM), while only two have specifically reported stresses at the pars interarticularis (PI) with posterior element resection. These studies have been performed utilizing a single subject, questioning their applications to a broader population. PURPOSE: We investigate the effect of graded PI resection in a three-dimensional manner on PI stress to provide surgical guidelines for avoidance of iatrogenic instability following lumbar laminectomy. Additionally, quantified FJF and IVD stresses can provide further insight into the development of adjacent segment disease. STUDY DESIGN: Biomechanical finite element (FE) method investigation of the lumbar spine. METHODS: FE models of the lumbar spine of three subjects were created using the open-source finite element software, FEBio. Single-level laminectomy, two-level laminectomy, and ventral-to-dorsal PI resection simulations were performed with varying degrees of PI resection from 0% to 75% of the native PI. These models were taken through cardinal ROM under standard loading conditions and PI stresses, FJF, IVD stresses, and ROM were analyzed. RESULTS: The three types of laminectomy simulated in this study showed a nonlinear increase in PI stress with increased bone resection. Axial rotation generated the most stress at the PI followed by flexion, extension and lateral bending. At 75% bone resection all three types of laminectomy produced PI stresses that were near the ultimate strength of human cortical bone during axial rotation. FJF decreased with increased bone resection for the three laminectomies simulated. This was most notable in axial rotation followed by extension and lateral bending. IVD stresses varied greatly between the nonsurgical models and likewise the effect of laminectomy on IVD stresses varied between subjects. ROM was mostly unaffected by the laminectomies performed in this study. CONCLUSIONS: Regarding the risk of iatrogenic spondylolisthesis, the combined results are sufficient evidence to suggest surgeons should be particularly cautious when PI resection exceeds 50% bone resection for all laminectomies included in this study. Lastly, the effects seen in FJF and IVD stresses indicate the degree to which the remainder of the spine must experience compensatory biomechanical changes as a result of the surgical intervention.

Hangman's Fracture.

STUDY DESIGN: Review article. OBJECTIVE: A review and update of the treatment of Hangman's fractures including the indications for both nonoperative and operative treatment of typical and atypical fractures. SUMMARY OF BACKGROUND DATA: Hangman's fractures are the second most common fracture pattern of the C2 vertebrae following odontoid fractures. Many of the stable extension type I and II fractures can be treated with external immobilization, whereas the predominant flexion type IIa and III fractures require surgical stabilization. METHODS: A review of the literature. RESULTS: The clinical and radiographic outcomes of the treatment of Hangman's fractures lend a good overall prognosis when the correct diagnosis is made. The nonoperative treatment of stable type I and II fractures with external immobilization leads to excellent long-term outcomes as does the operative treatment of the unstable type IIa and III fractures. CONCLUSIONS: Hangman's fractures can be classified as stable (type I and most II) or unstable (type IIa and III) and the optimal treatment depends upon this distinction. Stable injuries do well with rigid immobilization and rarely require operative intervention. In contrast, unstable injuries do poorly if treated nonoperatively but do well with surgical intervention. When treating atypical Hangman's variants, great vigilance and close clinical observation is paramount if nonoperative treatment is indicated given the potential for neurological compression in this fracture pattern. Properly identifying and treating these injuries represents an opportunity for the spine surgeon to optimize patient outcomes.

The Impact of Preoperative Mindfulness-Based Stress Reduction on Postoperative Outcomes in Lumbar Spine Degenerative Disease: 3-Month and 12-Month Results of a Pilot Study.

BACKGROUND: We previously reported inpatient and 30-day postoperative patient-reported outcomes (PROs) of a controlled, noncrossover pilot study using preoperative mindfulness-based stress reduction (MBSR) training for lumbar spine surgery. Our goal here was to assess 3-month and 12-month postoperative PROs of preoperative MBSR in lumbar spine surgery for degenerative disease. METHODS: Intervention group participants were prospectively enrolled in a preoperative online MBSR course. A comparison standard care only group was one-to-one matched retrospectively by age, sex, surgery type, and prescription opioid use. Three-month and 12-month postoperative PROs for pain, disability, quality of life, and opioid use were compared within and between groups. Regression models were used to assess whether MBSR use predicted outcomes. RESULTS: Twenty-four participants were included in each group. At 3 months, follow-up was 87.5% and 95.8% in the comparison and intervention groups, respectively. In the intervention group, mean Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF) was significantly higher, whereas mean Patient-Reported Outcomes Measurement Information System-Pain Interference (PROMIS-PI) and Oswestry Disability Index were significantly lower. The change from baseline in mean PROMIS-PF and PROMIS-PI was significantly greater than in the comparison group. At 12 months, follow-up was 58.3% and 83.3% in the comparison and intervention groups, respectively. In the intervention group, mean PROMIS-PI was significantly lower and change in mean PROMIS-PI from baseline was significantly greater. MBSR use was a significant predictor of change in PROMIS-PF at 3 months and in PROMIS-PI at 12 months. No adverse events were reported. CONCLUSIONS: Three-month and 12-month results suggest that preoperative MBSR may have pain control benefits in lumbar spine surgery.

The impact of the lordosis distribution index on failure after surgical treatment of adult spinal deformity.

BACKGROUND CONTEXT: Proximal junctional failure (PFJ) is a common and dreaded complication of adult spinal deformity. Previous research has identified parameters associated with the development of PJF and the search for radiographic and clinical variables continues in an effort to decrease the incidence of PFJ. The lordosis distribution index (LDI) is a parameter not based on pelvic incidence. Ideal values for LDI have been established in prior literature with demonstrated association with PJF. PURPOSE: The purpose of this study is compare PJF and mechanical failure rates between patients with ideal and nonideal LDI cohort. STUDY DESIGN: This is a retrospective, single-center case-controlled study. PATIENT SAMPLE: Adult patients who underwent surgical treatment for spinal deformity as defined by the SRS-Schwab criteria between 2001 and 2016 were included. Furthermore, fusion constructs spanned at least four vertebral segments with the upper instrumented vertebra (UIV) T9 or caudal. Patients who were under the age of 18, those with radiographic data less than 1 year, and those with neoplastic or trauma etiologies were excluded. Prior thoracolumbar spine surgery was not an exclusion criterion. OUTCOME MEASURES: The outcome measures were physiologic in nature: The primary outcome was defined as PFJ. The International Spine Study Group (ISSG) definition for PJF was used, which includes postoperative fracture of the UIV or UIV+1, instrumentation failure at UIV, PJA increase greater than 15° from preoperative baseline or extension of the construct needed within 6 months. Secondary outcomes included extension of the construct after 6 months or revision due to instrumentation failure, pseudarthrosis or distal junctional failure. METHODS: A portion of this project was funded through National Institute of Health Grant 5UL1TR001067-05. The authors have no conflict of interest related to this study. The records of patients meeting the inclusion criteria were reviewed. Clinical and radiographic data were extracted and analyzed. Univariate cox proportional hazard models were used to identify factors associated with mechanical failure and included in a multivariate Cox proportional hazards model. RESULTS: There were 187 patients that met the inclusion criteria. Univariate analysis demonstrated the number of levels fused, instrumentation to the sacrum or pelvis, PI-LL difference between pre- and postoperative states, T1-SPI, T9-SPI, and postoperative LDI (treated as a continuous variable). When LDI was treated as a categorical variable using an LDI cutoff of less than 0.5 for hypolordotic, 0.5 to 0.8 for aligned and greater than 0.8 for hyperlordotic, there was no difference in failure rates between the two groups. CONCLUSIONS: Lumbar lordosis is an important parameter in adult deformity. However, the LDI is an imperfect variable and previously developed categories did not show differences in failure rates in this cohort.

Potential Selection Bias in Observational Studies Comparing Cervical Disc Arthroplasty to Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective study using a national administrative database. OBJECTIVE: To define the cohort differences in patient characteristics between patients undergoing cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) in a large national sample, and to describe the impact of those baseline patient characteristics on analyses of costs and complications. SUMMARY OF BACKGROUND DATA: CDA was initially studied in high quality, randomized trials with strict inclusion criteria. Recently a number of non-randomized, observational studies have been published an attempt to expand CDA indications. These trials are predisposed to falsely attributing differences in outcomes to an intervention due to selection bias. METHODS: Adults undergoing ACDF or CDA between 2004 and 2014 were identified using International Classification of Diseases, 9, Clinical Modification (ICD-9-CM) diagnosis and procedure codes. Perioperative demographics, comorbidities, complications, and costs were queried. Patient characteristics were compared via chi-square and t tests. Cost, mortality, and complications were compared between ACDF and CDA cohorts using models that adjusted for demographics and comorbidities, as well as "naïve" models that did not. RESULTS: A total of 290,419 procedures, 98.2% ACDF and 1.8% CDA, were included in the sample. Compared with ACDF patients, CDA patients were younger, healthier as evidenced by number of comorbidities, and had an improved socioeconomic status as measured by income and insurance. The naïve logistic regression model showed that hospital costs for CDA were $549 lower than ACDF. In the fully specified model, CDA was $574 more expensive. The naïve model for medical complications suggests a protective advantage for CDA over ACDF, odds ratio of 0.627, P < 0.01. No statistically significant difference was found in the fully specified model in terms of complications. CONCLUSION: Patients undergoing CDA were younger and healthier with higher socioeconomic statuses compared with ACDF patients. Accounting for these baseline differences significantly attenuated the apparent benefit for CDR on costs and medical complications. LEVEL OF EVIDENCE: 3.

Defining Instability in Degenerative Spondylolisthesis: Surgeon Views.

STUDY DESIGN: Surgeon survey. OBJECTIVE: To examine factors influencing surgeons' definition of instability in grade 1 degenerative spondylolisthesis (DS) and assess treatment preferences for both stable and unstable DS. SUMMARY OF BACKGROUND DATA: DS treatment options are broadly classified as decompression with or without fusion. In surgical decision-making, "instability" is frequently considered as a key factor. However, no consensus on the definition of instability exists. METHODS: A survey was conducted to ascertain the minimum amounts of static translation, dynamic translation, and angulation change that surgeons considered significant for determining instability. The importance of other clinical and radiographic features were also assessed, and respondents' standard treatment for stable and unstable DS. RESULTS: Out of 226 respondents, 99% deemed dynamic translation moderately to extremely influential for determining instability, whereas only 55% found static translation as important. The most prevalent cut-off values for dynamic (57%) and static translation (32%) were at least 2-4 mm and for angulation change at least 10-15 degrees (43%). Facet angulation was considered moderately to extremely important to determine instability by 69% of the surgeons, disk height by 67%, patient age by 64%, severity of stenosis by 55%, severity of back pain by 50%, patient-reported function by 49%, pelvic incidence by 47%, and severity of neurogenic claudication by 42%.Decompression with fusion was the preferred treatment method for unstable DS in 99% of the respondents. For stable DS, 40% would still perform fusion, whereas 60% preferred treatment with decompression-alone. Those who preferred fusion for stable DS reported significantly lower thresholds for static (P<0.001) and dynamic translation (P=0.004) for their determination of instability. CONCLUSIONS: Clear consensus regarding the definition of instability does not exist. Dynamic translation is the most agreed-upon parameter of influence. Treatment preferences vary for stable DS, but for unstable cases there is broad consensus to perform fusion. LEVEL OF EVIDENCE: Level II.

Composer-Visual Cohort Analysis of Patient Outcomes.

OBJECTIVE: Visual cohort analysis utilizing electronic health record data has become an important tool in clinical assessment of patient outcomes. In this article, we introduce Composer, a visual analysis tool for orthopedic surgeons to compare changes in physical functions of a patient cohort following various spinal procedures. The goal of our project is to help researchers analyze outcomes of procedures and facilitate informed decision-making about treatment options between patient and clinician. METHODS: In collaboration with orthopedic surgeons and researchers, we defined domain-specific user requirements to inform the design. We developed the tool in an iterative process with our collaborators to develop and refine functionality. With Composer, analysts can dynamically define a patient cohort using demographic information, clinical parameters, and events in patient medical histories and then analyze patient-reported outcome scores for the cohort over time, as well as compare it to other cohorts. Using Composer's current iteration, we provide a usage scenario for use of the tool in a clinical setting. CONCLUSION: We have developed a prototype cohort analysis tool to help clinicians assess patient treatment options by analyzing prior cases with similar characteristics. Although Composer was designed using patient data specific to orthopedic research, we believe the tool is generalizable to other healthcare domains. A long-term goal for Composer is to develop the application into a shared decision-making tool that allows translation of comparison and analysis from a clinician-facing interface into visual representations to communicate treatment options to patients.

Software-Based Postoperative Communication With Patients Undergoing Spine Surgery.

STUDY DESIGN: Observational study. OBJECTIVES: Perioperative patient anxiety is a major concern in orthopedic surgery. Mobile messaging applications have been used in a number of healthcare settings. The goal of this project is to develop a novel mobile messaging application aimed at decreasing perioperative patient anxiety in spine surgery patients. METHODS: Postoperative recovery journals were collected from patients undergoing spine surgery. Journals were used as a framework to develop a software-messaging library. A subsequent cohort of patients received daily text messages with educational material regarding their recovery for 14 days after discharge from their operative admission. Patients ranked the usefulness of the survey on day 14; further feedback was obtained via interviews. RESULTS: Nineteen postoperative recovery journals were collected and analyzed. Content regarding postoperative recovery was compiled. The pilot group consisted of 21 patients. Average rating of the application on a 1 to 5 scale with 5 being "very useful" was 4.57. Of the 12 patients available for postoperative interviews, 11 felt the content of the messages was relevant. Nine of 12 patients felt the application made it less likely for them to call clinic. CONCLUSIONS: The study presents a unique mobile phone messaging tool to offer patients support in the 2 weeks following spine surgery. The tool was felt to be useful by nearly all patients, had a high degree of patient engagement, and made the majority of patients less likely to call clinic.

The Impact of Preoperative Mindfulness-Based Stress Reduction on Postoperative Patient-Reported Pain, Disability, Quality of Life, and Prescription Opioid Use in Lumbar Spine Degenerative Disease: A Pilot Study.

BACKGROUND: Prescription opioid medications negatively affect postoperative outcomes after lumbar spine surgery. Furthermore, opioid-related overdose death rates in the United States increased by 200% between 2000 and 2014. Thus, alternatives are imperative. Mindfulness-based stress reduction (MBSR), a mind-body therapy, has been associated with improved activity and mood in opioid-using patients with chronic pain. This study assessed whether preoperative MBSR is an effective adjunct to standard postoperative care in adult patients undergoing lumbar spine surgery for degenerative disease. METHODS: The intervention group underwent a preoperative online MBSR course. The comparison group was matched retrospectively in a 1:1 ratio by age, sex, type of surgery, and preoperative opioid use. Prescription opioid use during hospital admission and at 30 days postoperatively were compared with preoperative use. Thirty-day postoperative patient-reported outcomes for pain, disability, and quality of life were compared with preoperative patient-reported outcomes. Dose-response effect of mindfulness courses was assessed using Mindful Attention Awareness Scale scores. RESULTS: In this pilot study, 24 participants were included in each group. Most intervention patients (70.83%) completed 1 session, and the mean Mindful Attention Awareness Scale score was 4.28 ± 0.71 during hospital admission. At 30 days, mean visual analog scale back pain score was lower in the intervention group (P = 0.004) but other patient-reported outcomes did not differ. CONCLUSIONS: During hospital admission, no significant dose-response effect of mindfulness techniques was found. At 30 days postoperatively, MBSR use was associated with less back pain. Further research is needed to assess the effectiveness of preoperative MBSR on postoperative outcomes in lumbar spine surgery for degenerative disease.

Trends in Lumbar Fusion Procedure Rates and Associated Hospital Costs for Degenerative Spinal Diseases in the United States, 2004 to 2015.

STUDY DESIGN: Analysis of National Inpatient Sample (NIS), 2004 to 2015. OBJECTIVE: Describe recent trends in US rates of lumbar fusion procedures and associated costs, by surgical indication. SUMMARY OF BACKGROUND DATA: Spinal fusion is appropriate for spinal deformity and instability, but evidence of effectiveness is limited for primary disc herniation and spinal stenosis without instability. It remains controversial for treatment of axial pain secondary to degenerative disc disease. There are potential non-instability, non-deformity indications for fusion surgery, including but not limited to severe foraminal stenosis and third-time disc herniation. METHODS: Elective lumber fusion trends were reported using Poisson regression, grouped by indication as degenerative scoliosis, degenerative spondylolisthesis, spinal stenosis, disc herniation, and disc degeneration. Generalize linear regression was used to estimate trends in hospital costs, adjusted for age, sex, indication, comorbidity, and inflation. RESULTS: Volume of elective lumbar fusion increased 62.3% (or 32.1% per 100,000 US adults), from 122,679 cases (60.4 per 100,000) in 2004 to 199,140 (79.8 per 100,000) in 2015. Increases were greatest among age 65 or older, increasing 138.7% by volume (73.2% by rate), from 98.3 per 100,000 (95% confidence interval [CI] 97.2, 99.3) in 2004 to 170.3 (95% CI 169.2, 171.5) in 2015. Although the largest increases were for spondylolisthesis (+47,390 operations, 111%) and scoliosis (+16,129 operations, 186.6%), disc degeneration, herniation, and stenosis combined to accounted for 42.3% of total elective lumbar fusions in 2015. Aggregate hospital costs increased 177% during these 12 years, exceeding $10 billion in 2015, and averaging more than $50,000 per admission. CONCLUSION: While the prevalence of spinal pathologies is not known, the rate of elective lumbar fusion surgery in the United States increased most for spondylolisthesis and scoliosis, indications with relatively good evidence of effectiveness. The proportion of fusions coded for indications with less evidence of effectiveness has slightly decreased in the most recent years. LEVEL OF EVIDENCE: 3.