Search

Preoperative prediction of prolonged postoperative opioid prescription helps identify patients for increased surveillance after surgery. The SORG machine learning model has been developed and successfully tested using 5,413 patients from the United States (US) to predict the risk of prolonged opioid prescription after surgery for lumbar disc herniation. However, external validation is an often-overlooked element in the process of incorporating prediction models in current clinical practice. This cannot be stressed enough in prediction models where medicolegal and cultural differences may play a major role.The authors aimed to investigate the generalizability of the US citizens prediction model SORG to a Taiwanese patient cohort.Retrospective study at a large academic medical center in Taiwan.Of 1,316 patients who were 20 years or older undergoing initial operative management for lumbar disc herniation between 2010 and 2018.The primary outcome of interest was prolonged opioid prescription defined as continuing opioid prescription to at least 90 to 180 days after the first surgery for lumbar disc herniation at our institution.Baseline characteristics were compared between the external validation cohort and the original developmental cohorts. Discrimination (area under the receiver operating characteristic curve and the area under the precision-recall curve), calibration, overall performance (Brier score), and decision curve analysis were used to assess the performance of the SORG ML algorithm in the validation cohort. This study had no funding source or conflict of interests.Overall, 1,316 patients were identified with sustained postoperative opioid prescription in 41 (3.1%) patients. The validation cohort differed from the development cohort on several variables including 93% of Taiwanese patients receiving NSAIDS preoperatively compared with 22% of US citizens patients, while 30% of Taiwanese patients received opioids versus 25% in the US. Despite these differences, the SORG prediction model retained good discrimination (area under the receiver operating characteristic curve of 0.76 and the area under the precision-recall curve of 0.33) and good overall performance (Brier score of 0.028 compared with null model Brier score of 0.030) while somewhat overestimating the chance of prolonged opioid use (calibration slope of 1.07 and calibration intercept of -0.87). Decision-curve analysis showed the SORG model was suitable for clinical use.Despite differences at baseline and a very strict opioid policy, the SORG algorithm for prolonged opioid use after surgery for lumbar disc herniation has good discriminative abilities and good overall performance in a Han Chinese patient group in Taiwan. This freely available digital application can be used to identify high-risk patients and tailor prevention policies for these patients that may mitigate the long-term adverse consequence of opioid dependence: https://sorg-apps.shinyapps.io/lumbardiscopioid/.

BACKGROUND CONTEXT Preoperative survival estimation in spinal metastatic disease helps determine the appropriateness of invasive management. The SORG ML 90-day and 1-year machine learning algorithms for survival in spinal metastatic disease were previously developed in a single institutional sample but remain to be externally validated. PURPOSE The purpose of this study was to externally validate these algorithms in an independent population from another institution. STUDY DESIGN/SETTING Retrospective study at a large, tertiary care center. PATIENT SAMPLE Patients 18 years or older who underwent surgery between 2003 and 2016. OUTCOME MEASURES Ninety-day and 1-year mortality. METHODS Baseline characteristics of the validation cohort were compared to the developmental cohort for the SORG ML algorithms. Discrimination (c-statistic and receiver operating curve), calibration (calibration slope, intercept, calibration plot, and observed proportions by predicted risk groups), overall performance (Brier score), and decision curve analysis were used to assess the performance of the SORG ML algorithms in the validation cohort. RESULTS Overall, 176 patients underwent surgery for spinal metastatic disease, of which 44 (22.7%) experienced 90-day mortality and 99 (56.2%) experienced 1-year mortality. The validation cohort differed significantly from the developmental cohort on primary tumor histology, metastatic tumor burden, previous systemic therapy, overall comorbidity burden, and preoperative laboratory characteristics. Despite these differences, the SORG ML algorithms generalized well to the validation cohort on discrimination (c-statistic 0.75–0.81 for 90-day mortality and 0.77–0.78 for 1-year mortality), calibration, Brier score, and decision curve analysis. CONCLUSION and RELEVANCE Initial results from external validation of the SORG ML 90-day and 1-year algorithms for survival prediction in spinal metastatic disease suggest potential utility of these digital decision aids in clinical practice. Further studies are needed to validate or refute these algorithms in large patient samples from prospective, international, multi-institutional trials.

Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio have been previously identified as markers for overall survival in oncology but remain heretofore unexplored in spinal epidural abscess (SEA).The purpose of this study was to determine the impact of these routinely collected assessments on 90-day mortality in SEA.Retrospective, case-control study.Patients 18 years or older diagnosed with SEA at 2 academic medical centers and 3 community hospitals.Ninety-day postdischarge and in-hospital mortality.Complete blood count with differential obtained on the day immediately preceding or on the day of admission was used to calculate platelet to lymphocyte and neutrophil to lymphocyte ratios. Multivariate analyses were used to determine if these ratios were independent risk factors for 90-day mortality.For 1,053 SEA patients included in the study, the rate of 90-day mortality was 134 (12.7%). The rate of 90-day mortality with neutrophil to lymphocyte ratio (≥8) was (20.5%) compared to (8.1%) with neutrophil to lymphocyte ratio8. Neutrophil to lymphocyte ratio was positively associated with bacteremia, elevated erythrocyte sedimentation rate, and concurrent systemic infections (endocarditis, meningitis) and negatively associated with duration of symptoms prior to presentation. On multivariate analysis, elevated neutrophil to lymphocyte remained an independent risk factor for 90-day mortality (odds ratio=2.62, 95% confidence interval=1.66-4.17, p.001). Platelet to lymphocyte ratio was not associated with 90-day mortality.Absolute neutrophil to lymphocyte ratio is a routinely collected but overlooked biomarker in patients with spinal epidural abscess that is a novel independent risk factor for 90-day mortality.

None of the existing prognostic scoring systems for spinal epidural abscess (SEA) include albumin despite albumin's established role in inflammation, nutrition, lipid peroxidation, and regulation of apoptosis. The purpose of the present study was to determine the prognostic value of albumin in SEA.We performed a retrospective, case-control study of 2 independent data sets: patients with SEA in an institutional population and patients in the National Surgical Quality Improvement Program (NSQIP). Bivariate analyses and multivariate analyses were used to determine whether albumin is an independent prognostic factor for survival in both data sets.For the 1053 patients with SEA in the institutional cohort, the 90-day postdischarge mortality was 134 (12.7%). Overall, 633 (60.1%) underwent surgery in the initial admission, with a 30-day postoperative mortality rate of 5.5% (n = 35). For the 1154 patients with SEA in the NSQIP database, the 30-day postoperative mortality rate was 3.6% (n = 42). The rate of 90-day postdischarge mortality in the institutional cohort for patients with albumin2.3 g/dL was 25.1%. In contrast, the rate for patients with albumin3.3 g/dL was 4.5%. On multivariate analysis of the NSQIP database, hypoalbuminemia was an independent prognostic factor for 30-day postoperative mortality. On multivariate analysis of the institutional cohort, hypoalbuminemia remained a prognostic factor for 90-day postdischarge mortality.Albumin was validated as an independent prognostic factor in patients with SEA. The lack of this marker in existing scoring systems underscores the need for updated models to optimize risk stratification and shared decision-making before surgery.

Background Context: Postoperative morbidity may offset the potential benefits of surgical treatment for spine metastatic disease; hence, risk factors for postoperative complications and reoperations should be taken into considerations during surgical decision-making. In addition, it remains unknown whether complications and reoperations shorten these patients’ survival. Purpose: We aimed to describe and identify factors associated with having a complication within 30 days of index surgery as well as factors associated with having a subsequent reoperation. Furthermore, we assessed the effect of 30-day complications and reoperations on the patients’ postoperative survival, as well as described neurologic changes after surgery. Study Design: Retrospective cohort study. Patient Sample: We included 647 patients 18 years and older who had surgery for metastatic disease in the spine between January 2002 and January 2014 in one of two affiliated tertiary care centers. Outcome Measures: Our primary outcomes were complications within 30 days after surgery and reoperations until final follow-up or death. Methods: We used multivariate logistic regression to identify risk factors for 30-day complications and reoperations. We used the Cox regression analysis to assess the effect of postoperative complications and reoperations on survival. Results: From 647 included patients, 205 (32%) had a complication within 30 days. The following variables were independently associated with 30-day complications: lower albumin levels (odds ratio [OR]: 0.69, 95% confidence interval [CI]=0.49–0.96, p=.021), additional comorbidities (OR=1.42, 95% CI=1.00–2.01, p=.048), pathologic fracture (OR=1.41, 95% CI=0.97–2.05, p=.031), three or more spine levels operated upon (OR=1.64, 95% CI=1.02–2.64, p=.027), and combined surgical approach (OR=2.44, 95% CI=1.06–5.60, p=.036). One hundred and fifteen patients (18%) had at least one reoperation after the initial surgery; prior radiotherapy (OR=1.56, 95% CI=1.07–2.29, p=.021) to the spinal tumor was independently associated with reoperation. 30-day complications were associated with worse survival (hazard ratio [HR]=1.40, 95% CI=1.17–1.68, p

Background Chordomas are locally invasive slow-growing tumors that are difficult to study because of the rarity of the tumors and the lack of significant volumes of patients with longitudinal follow-up. As such, there are currently no machine learning studies in the chordoma literature. The purpose of this study was to develop machine learning models for survival prediction and deploy them as open access web applications as a proof of concept for machine learning in rare nervous system lesions. Methods The National Cancer Institute's Surveillance, Epidemiology, and End Results program database was used to identify adult patients diagnosed with spinal chordoma between 1995 and 2010. Four machine learning models were used to predict 5-year survival for spinal chordoma and assessed by discrimination, calibration, and overall performance. Results The 5-year overall survival for 265 patients with spinal chordoma was 67.5%. Variables used for prediction were age at diagnosis, tumor size, tumor location, extent of tumor invasion, and extent of surgery. For 5-year survival prediction, the Bayes Point Machine achieved the best performance with a c statistic of 0.80, calibration slope of 1.01, calibration intercept of 0.03, and Brier score of 0.16. This model for 5-year mortality prediction was incorporated into an open access application and can be found online ( https://sorg-apps.shinyapps.io/chordoma/ ). Conclusions This analysis of patients with spinal chordoma demonstrated that machine learning models can be developed for survival prediction in rare pathologies and have the potential to serve as the basis for creation of decision support tools in the future.

Patients with musculoskeletal illness often report that pain interferes with their ability to engage in activities of daily living. Catastrophic thinking is consistently depicted as an important cognitive factor that hinders adjustment to pain. Current research has also shown that pain negatively impacts an individual's ability to maintain attention on the task at hand. While a measure of the experience of cognitive intrusion of pain (ECIP) has been recently developed to quantify the extent of that impact, little research has explored this issue in everyday settings. This study tested the mediating roles of cognitive intrusion of pain and pain catastrophizing scale (PCS) on the association of pain intensity with pain interference in 142 patients with upper-extremity musculoskeletal illness. We found that both cognitive intrusion of pain (b = 0.136, bootstrap SE = 0.048, 95% BCa CI [0.052, 0.245]) and pain catastrophizing (b = 0.114, bootstrap SE = 0.044, 95% BCa CI [0.047, 0.221]) partly and independently mediated the relationship between pain intensity and pain interference. Although comparable, the mediation effect of cognitive intrusion of pain was slightly larger than that of pain catastrophizing (25.7%, bootstrap SE = 0.094 vs. 21.5%, bootstrap SE = 0.080). Results suggest that pain sensations can interfere with activities of daily living through two distinct mechanisms. A combination of traditional cognitive behavioral therapy and mindfulness skills training targeting both pain catastrophizing and cognitive intrusion has the potential to decrease pain interference and help patients return to normal healthy living in spite of acute or persistent pain.

BACKGROUND CONTEXT Reconstruction of the mobile spine following total en bloc spondylectomy (TES) of one or multiple vertebral bodies in patients suffering from malignant spinal tumors is a challenging procedure with high failure rates. One of the most common reasons for reconstructive failure is nonunion, which is an even greater problem in the setting of local radiation. Radiation is an integral part of the management of primary malignant bone tumors in the spine at our institution. Vascularized grafts may help prevent nonunion in the setting of radiation therapy. We have routinely utilized free vascularized fibular grafts (FVFG) for the reconstruction of the mobile spine following TES. PURPOSE The purpose of this study is to describe the surgical technique utilized for vascularized reconstruction of defects following TES. In addition, we report the outcomes of a consecutive series of patients treated with this technique. STUDY DESIGN/SETTING Retrospective review of electronic health records at one tertiary care center and an illustrated explanation of the surgical technique. PATIENT SAMPLE Adult patients, 18 years or older, undergoing total en bloc resection of primary malignant tumors of the mobile spine followed by reconstruction using a free vascularized fibula graft. OUTCOME MEASURES The primary outcome was reconstruction failure of the construct. METHODS Thirty-nine patients treated at our tertiary care institution between 2010 and 2018 for a diagnosis of malignant tumor in the mobile spine with the use of FVFG following TES were reviewed. Postoperative union, complications, neurological outcome, reoperations, and survival were reported. The median time of follow-up was 50 months (range, 14 – 109 months). RESULTS The cohort consisted of 26 males and 13 females, with a median age of 58 years. Chordoma was the tumor that occurred most often (67%) and tumors occurred most often in the lumbar spine (46%). Complete union was seen in 26 patients (76%), the overall complication rate was 56%, and instrumentation failure was the most common complication with 26% of patients affected. In total 12 patients (31%) suffered from – instrumentation loosening or breakage, nonunion, graft fracture, or a combination of these – for which ten patients (26%) required revision surgery. The fixation was revised a total of 15 times (42% of reoperations). In 18 patients (46%) one or more reoperations were needed. The overall 1-, 3-, and 5-year survival rate was 95%, 92%, and 87%, respectively. CONCLUSIONS The FVFG is an adequate reconstruction technique of the mobile spine following TES for malignant tumors. Although we see higher union rates and comparable complication rates compared to other techniques, the rate of instrumentation failure was high. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

There is an increasing number of clinical prediction models in spine surgery based on machine learning. The purpose of this manuscript is to review 1) the outcomes they have focused on, 2) which models have been externally validated, and 3) how studies report their performance measures. Only 2 of 39 prediction models have been externally validated and complications were the most studied topics. Area under the curve (AUC) was the most frequently used performance measure, while calibration and decision-curve analysis are poorly reported. Future studies should focus on external validation of existing models. Publications on the development of models should include all fundamental performance measures and consider including a decision-curve analysis.

In recent years, the volume and complexity of electronic patient-generated health data has increased exponentially leading to unprecedented opportunities for automated extraction of clinical features from free-text medical note and speech. Natural language processing (NLP), a branch of computer science that focuses on enabling computers to process human language, can process this rich resource of data for clinical and research purposes. In this narrative review, we provide the fundamentals of NLP and discuss the potentials and challenges in the spinal community. This lays a foundation for the reader to better understand and appreciate the role that NLP will play in the evolving field of artificial intelligence.

BACKGROUND CONTEXT The prevalence of symptomatic and asymptomatic synovial facet cysts in the lumbar spine has been incompletely established, and although many studies demonstrate an association with degenerative spine disease, no cumulative increase in prevalence of synovial facet cysts with increasing age has been presented. PURPOSE To assess the prevalence of incidental (ie, asymptomatic) and symptomatic lumbar synovial facet cysts on MRI. Secondarily, we will assess if the prevalence of lumbar synovial facet cysts increases with age and what other factors are associated with its prevalence. In addition, we will assess differences in patient and cyst characteristics between asymptomatic and symptomatic facet cysts. STUDY DESIGN/SETTING Retrospective cohort study from two affiliated tertiary care referral centers for spine disease. PATIENT SAMPLE A total of 19,010 consecutive patients who underwent a dedicated lumbar spine MRI between 2004 and 2015. OUTCOME MEASURES Symptomatic and asymptomatic facet cysts. METHODS A symptomatic cyst was defined as a cyst with symptoms of radiculopathy on the same side as the cyst. The prevalence of incidental, symptomatic, and overall synovial facet cysts was reported as a percentage with 95% confidence interval (95% CI). Multivariable logistic regression analysis was used to assess if age, sex, race, and indication for MRI were associated with having a facet cyst. Generalized estimating equation analysis was used to assess differences between symptomatic versus asymptomatic synovial facet cyst: age, sex, race, side, level, cyst size, and cyst location. RESULTS The overall synovial facet cyst prevalence was 6.5% (95% CI: 6.1–6.8) [1,228/19,010]. These 1,228 patients had 1,553 synovial facet cysts of which 46% cysts (721/1,553) were incidental and 54% cysts (832/1,553) were symptomatic. The prevalence of having one or more incidental synovial facet cysts was 2.7% (95% CI: 2.5%–3.0%) [518/19,010], the prevalence of having one or more symptomatic synovial facet cysts was 3.2% (95% CI: 3.0%–3.5%) [617/19,010], and the prevalence of having both one or more incidental and one or more symptomatic synovial facet cysts was 0.49% (95% CI: 0.39%–0.59%) [93/19,010]. Increased age was independently associated with a higher likelihood of having a synovial facet cyst (odds ratio [per 10years increase in age]: 1.24, 95%CI: 1.20–1.29, p CONCLUSIONS Approximately 1 in 15 patients has at least one synovial facet cyst and about half of them are symptomatic and half are asymptomatic. Having a facet cyst — symptomatic and asymptomatic — is strongly associated with increased age supporting the theory that degenerative spine disease underlies development of facet cysts. Large cyst size and anterior location of the cysts are associated with an increased likelihood of having neurological symptoms.

Purpose To identify factors associated with unplanned reoperation of severely injured index fingers and to address the number of amputations after initial repair. Methods In this retrospective study, we included all patients older than 18 years of age who had repair or immediate amputation for combined index finger injury at 2 level I trauma centers and 1 community hospital tied to a level I trauma center between January 2004 and February 2014. Twelve patients were excluded because of inadequate follow-up. Bivariate and multivariable analyses sought factors associated with unplanned reoperation after repair and immediate amputation. Results Among 114 patients with combined injury, 75 were treated with repair and 39 with immediate amputation. A total of 41 patients had an unplanned reoperation, 33 after repair (44%) and 8 after immediate amputation (21%). In multivariable analysis, patients who had a reoperation for fingers other than the index finger were at risk for unplanned reoperation after repair. Women were more likely to have an unplanned reoperation than men, and patients who had a ray amputation were at risk for unplanned reoperation after immediate amputation. Six patients (18%) had amputation after initial repair. Conclusions Surgeons may counsel patients that they are twice as likely to have an unplanned reoperation after a repair for combined injury of the index finger compared with an immediate amputation. Unplanned reoperations were more common among patients with injuries involving multiple fingers. Effective shared decision making is particularly important in this setting given that 1 in 5 repaired index fingers were eventually amputated. Type of study/level of evidence Therapeutic IV.