Extreme weather events and military conflict over seven centuries in ancient Korea.

We explore the causal connection between weather and war by constructing and analyzing a dataset featuring extreme weather events and military conflicts involving a set of stable political entities that existed side by side over several centuries, namely, the three ancient kingdoms of the Korean Peninsula between 18 Before the Common Era and 660 Common Era. Conflicts are classified as desperate if a state experiencing the shock invades a neighbor and opportunistic if a state experiencing the shock is invaded by a neighbor. We find that weather-induced conflict was significant, but largely opportunistic rather than desperate. That is, states experiencing an adverse shock were more likely to be invaded, but not more likely to initiate attack. We also provide evidence that the channel through which weather shocks gave rise to opportunistic invasions was food insecurity, which weakened the power of states to repel attack. Since climate change is projected to give rise to an increased frequency of extreme weather events, these historical findings have contemporary relevance.

Machine learning applications to clinical decision support in neurosurgery: an artificial intelligence augmented systematic review.

Machine learning (ML) involves algorithms learning patterns in large, complex datasets to predict and classify. Algorithms include neural networks (NN), logistic regression (LR), and support vector machines (SVM). ML may generate substantial improvements in neurosurgery. This systematic review assessed the current state of neurosurgical ML applications and the performance of algorithms applied. Our systematic search strategy yielded 6866 results, 70 of which met inclusion criteria. Performance statistics analyzed included area under the receiver operating characteristics curve (AUC), accuracy, sensitivity, and specificity. Natural language processing (NLP) was used to model topics across the corpus and to identify keywords within surgical subspecialties. ML applications were heterogeneous. The densest cluster of studies focused on preoperative evaluation, planning, and outcome prediction in spine surgery. The main algorithms applied were NN, LR, and SVM. Input and output features varied widely and were listed to facilitate future research. The accuracy (F(2,19) = 6.56, p < 0.01) and specificity (F(2,16) = 5.57, p < 0.01) of NN, LR, and SVM differed significantly. NN algorithms demonstrated significantly higher accuracy than LR. SVM demonstrated significantly higher specificity than LR. We found no significant difference between NN, LR, and SVM AUC and sensitivity. NLP topic modeling reached maximum coherence at seven topics, which were defined by modeling approach, surgery type, and pathology themes. Keywords captured research foci within surgical domains. ML technology accurately predicts outcomes and facilitates clinical decision-making in neurosurgery. NNs frequently outperformed other algorithms on supervised learning tasks. This study identified gaps in the literature and opportunities for future neurosurgical ML research.

New Paradigms in the Continuum of Spine Care: From Newborns to Elderly Patients.

The evaluation and management of spinal disorders is complex and constantly evolving. Back pain and spinal deformity are substantial contributors to hospital and outpatient physician visits even for young patients. With new insights into the etiology, clinical presentation, and evaluation, children can be more accurately diagnosed and treated. Patients with adolescent idiopathic scoliosis may undergo selective fusion to preserve motion segments, and in some cases, vertebral body tethering or other growth-modification techniques may provide correction with motion preservation in this rapidly changing specialty. The understanding of spinopelvic parameters (pelvic incidence, pelvic tilt, sacral slope) and sagittal balance as they relate to clinical health status has provided surgeons with valuable guidance when managing pediatric and adult spinal deformity. An evidence-based approach to the management of spinal disorders across the continuum of ages has the goal of improving the value of care through optimization of outcomes and limitation of costs and complications. There are new paradigms in the management of spinal disorders and evidence-based approaches to the evaluation and management of patients across the ages.

Correction of severe spinopelvic mismatch: decreased blood loss with lateral hyperlordotic interbody grafts as compared with pedicle subtraction osteotomy.

OBJECTIVE Pedicle subtraction osteotomy (PSO) provides extensive correction in patients with fixed sagittal plane imbalance but is associated with high estimated blood loss (EBL). Anterior column realignment (ACR) with lateral graft placement and sectioning of the anterior longitudinal ligament allows restoration of lumbar lordosis (LL). The authors compare peri- and postoperative measures in 2 groups of patients undergoing correction of a sagittal plane imbalance, either through PSO or the use of lateral lumbar fusion and ACR with hyperlordotic (20°-30°) interbody cages, with stabilization through standard posterior instrumentation in all cases. METHODS The authors performed a retrospective chart review of cases involving a lumbar PSO or lateral lumbar interbody fusion and ACR (LLIF-ACR) between 2010 and 2015 at the authors' institution. Patients who had a PSO in the setting of a preexisting fusion that spanned more than 4 levels were excluded. Demographic characteristics, spinopelvic parameters, EBL, operative time, and LOS were analyzed and compared between patients treated with PSO and those treated with LLIF-ACR. RESULTS The PSO group included 14 patients and the LLIF-ACR group included 13 patients. The mean follow-up was 13 months in the LLIF-ACR group and 26 months in the PSO group. The mean EBL was significantly lower in the LLIF-ACR group, measuring approximately 50% of the mean EBL in the PSO group (1466 vs 2910 ml, p < 0.01). Total LL correction was equivalent between the 2 groups (35° in the PSO group, 31° in the LLIF-ACR group, p > 0.05), as was the preoperative PI-LL mismatch (33° in each group, p > 0.05) and the postoperative PI-LL mismatch (< 1° in each group, p = 0.05). The fusion rate as assessed by the need for reoperation due to pseudarthrosis was lower in the LLIF-ACR group but not significantly so (3 revisions in the PSO group due to pseudarthrosis vs 0 in the LLIF-ACR group, p > 0.5). The total operative time and LOS were not significantly different in the 2 groups. CONCLUSIONS This is the first direct comparison of the LLIF-ACR technique with the PSO in adult spinal deformity correction. The study demonstrates that the LLIF-ACR provides equivalent deformity correction with significantly reduced blood loss in patients with a previously unfused spine compared with the PSO. This technique provides a powerful means to avoid PSO in selected patients who require spinal deformity correction.

Vertebrobasilar Insufficiency Syndrome in Extension: Insights into Surgical Treatment.

BACKGROUND: Rotational vertebrobasilar artery syndrome, or bow hunter syndrome, is a rare yet well-documented pathology. This study presents a surgical approach to a latent manifestation of dynamic, extension-only, bilateral codominant vertebral artery compression in the V3 segment, associated with craniocervical instability and central canal stenosis. METHODS: The clinical presentation involves the treatment of positional vertigo resulting from left and high-grade right vertebral artery stenosis during neck extension only. Diagnosis was confirmed through a formal angiogram under provocative maneuvers. Surgical intervention, detailed in this section, employed a multidisciplinary approach, including intraoperative angiograms to ensure patent vertebral arteries precraniocervical fusion. RESULTS: The surgical treatment demonstrated success in addressing extension-only vertebrobasilar syndrome and associated complications of C1-2 pannus and craniocervical instability. Intraoperative angiograms confirmed vertebral artery patency pre- and postsurgical positioning, ensuring the effectiveness of the multidisciplinary approach. CONCLUSIONS: This study concludes by highlighting the successful multidisciplinary surgical treatment of a patient with nonunion of a C1 Jefferson fracture, leading to extension-only vertebrobasilar syndrome complicated by C1-2 pannus and craniocervical instability. The importance of considering vertebral artery dynamic stenosis in cases of positional vertigo or transient neurological symptoms following an injury is emphasized. Surgical stabilization, particularly when conservative measures prove ineffective, is recommended, with careful attention to pre- and postsurgical positioning to verify vertebral artery patency and posterior vasculature integrity.

Video-Assisted Thoracoscopic Lateral Interbody Fusion for Symptomatic Pseudarthrosis in Neurofibromatosis 1-Associated Spinal Deformity.

BACKGROUND: The treatment of symptomatic pseudarthrosis via posterior-only approaches in the setting of neurofibromatosis 1 (NF1) is challenging due to dural ectasias, resulting in erosion of the posterior elements. The purpose of this report is to illustrate a minimally invasive method for performing anterior thoracic fusion for pseudarthrosis in a patient with NF1-associated scoliosis and dysplastic posterior elements. To the best of our knowledge, this is the first documented case of using video-assisted thoracoscopic lateral interbody fusion to treat pseudarthrosis for NF1-associated spinal deformity. CASE DESCRIPTION: The patient underwent video-assisted thoracoscopic anterior spinal fusion via a direct lateral interbody approach with interbody cage placement at T10-T11 and T11-T12, followed by revision of his posterior spinal fusion and instrumentation. The patient had an uneventful postoperative course. At 6 months of follow-up, the patient had complete resolution of his preoperative symptoms and had returned to full-time work with no complaints. At 3 years postoperatively, the patient reported being satisfied with the operation and had continued to work full-time without restrictions. CONCLUSIONS: To the best of our knowledge, this is the first report of pseudarthrosis in the setting of NF1-associated scoliosis treated via minimally invasive anterior thoracic fusion facilitated by video-assisted thoracoscopic surgery. This is a powerful technique that allows for safe access for anterior thoracic fusion in the setting of dysplastic posterior anatomy and poor posterior bone stock.

Transdural retrieval of retropulsed transforaminal lumbar interbody fusion cages.

Transforaminal lumbar interbody fusions (TLIFs) are performed for various lumbar spine pathologies. Posterior migration of an interbody cage is a complication that may result in neurologic injury and require reoperation. Sparse information exists regarding the safety and efficacy of a transdural approach for cage retrieval. We describe a surgical technique, in which centrally retropulsed cages were safely retrieved transdurally. A patient with prior L3-S1 posterior lumbar fusion and L4-S1 TLIFs presented with radiculopathy and weakness in dorsiflexion. Imaging revealed posterior central migration of TLIF cages causing compression of the traversing L5 nerve root. Cages were removed transdurally; the correction was performed with an all-posterior T10-pelvis fusion. Aside from temporary weakness in right-sided dorsiflexion, the patient experienced complete resolution in their radiculopathy and strength returned to its presurgical state by 3 months. The transdural approach for interbody removal can be safely performed and should be a tool in the spine surgeon's armamentarium.

Does Pedicle Morphology Affect the Safety and Accuracy of Pedicle Screw Placement Using 3D-Printed Guides? A 5-Year, Single-Center Experience With 2210 Screws Placed for Adult Spinal Deformity Reconstruction.

BACKGROUND: Adult spinal deformity (ASD) surgery often involves the placement of pedicle screws using various methods, including freehand technique, fluoroscopic guidance, and computer-assisted intraoperative navigation, each with distinct limitations. Particularly challenging is the instrumentation of pedicles with small or absent cancellous channels (Watanabe types C and D pedicles), commonly found at the apex of large curves where precise screw placement is crucial for effective deformity correction. 3D-printed pedicle screw drill guides (3DPSG) may assist in accurately placing pedicle screws while minimally disrupting the standard ASD surgery workflow. This study aims to evaluate the safety and efficacy of 3DPSG in ASD patients with Watanabe types C and D pedicles, where the safe corridor for screw placement is limited. METHODS: 3DPSG were designed using fine cut (≤1.25 mm) computed tomography scans. Preoperative screw trajectory planning and guide manufacturing were conducted using computer-aided design software (Mighty Oak Medical, Englewood, CO). Four ASD surgeons with varying experience levels placed the guides. Data on patient demographics, pedicle morphology, number of levels instrumented, and implant-related complications were collected. RESULTS: The study included 115 patients (median age 67, range 18-81 years) with 2210 screws placed from T1 to L5. The median number of levels instrumented per case was 11 (range 7-12). Diagnoses included adult degenerative scoliosis (n = 62), adult idiopathic scoliosis (n = 30), Scheuermann's kyphosis (n = 2), and other complex conditions (n = 21). The overall accuracy rate for pedicle screw placement was 99.5%, with a 0% malposition rate in type C and D pedicles. No vascular or neurological complications or reoperations related to screw placement were reported. CONCLUSION: 3DPSG facilitates safe and accurate pedicle screw placement regardless of pedicle morphology in ASD surgeries. This includes the challenging Watanabe types C and D pedicles, typically found at curve apices, enabling surgeons to achieve high implant density and optimal spinal fixation in ASD patients.

Describing Functional Low Back Pain Disability in the American Population: A Crowd-sourced Evaluation of the Oswestry Disability Index.

BACKGROUND CONTEXT: The Oswestry Disability Index (ODI) is widely utilized as a patient reported outcome (PRO) tool to assess patients presenting with low back pain (LBP) and following thoracolumbar spine surgery. No primary study has calculated the baseline range of ODI values in the diverse American population. Establishing age-adjusted normative values for ODI in the American population is crucial for assessing the utility of treatment strategies. PURPOSE: The purpose of this study is to describe the baseline range of functional low back disability as measured by the ODI in an American population. STUDY DESIGN/SETTING: Cross-Sectional Observational Study. PATIENT SAMPLE: A total of 1214 participants were recruited from the United States in January 2024 using a combination of the Connect and PrimePanel platforms by CloudResearch to complete a survey administered on a RedCap online database. The survey consisted of 10 demographic questions and the 10 ODI survey questions. The distribution of the survey was designed to obtain approximately 100 respondents in each of the following age groups: 18-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-89. The distribution of the sample was similarly designed to match the US Census racial data with 78.1% White, 13.9% Black, and 7.9% other. OUTCOME MEASURES: Oswestry Disability Index (ODI). METHODS: A crowd-sourcing platform called Cloudresearch was used to collect a representative sample of the US population by answering questions of the Oswestry Disability Questionnaire (ODQ), a 10-question survey. RESULTS: The final sample size was 797 participants including 386 (48.4%) males and 411 (51.6%) females; 169 participants were excluded that did not complete the survey and an additional 248 were excluded for failing attention check questions. The overall mean ODI score for the combined age groups was 14.35 (95% CI [13.33, 15.37]). The mean ODI scores increased with age, with the highest mean ODI in ages 70-79 at 18.0 (95% CI [14.76, 21.24]). Female participants reported higher mean ODI scores than their male counterparts in the 18-29 age group (P = .01), 50-59 age group (P = .01), and 60-69 age group (P = .02). Additionally, a weak positive correlation was found between Body Mass Index (BMI) and ODI scores (r = 0.22, P < .001). CONCLUSION: Our findings demonstrate a clear trend of increased disability with age. This study describes the baseline range of functional low back pain disability in the US population. By defining these parameters, healthcare professionals can better tailor age and sex-specific interventions to manage disability in the aging U.S. population, ultimately improving patient care and both operative and non-operative treatment plans for LBP-related thoracolumbar pathology.

Monthly multidisciplinary complex spine conference: a cost-analysis utilizing time-driven activity-based costing.

PURPOSE: To understand costs and provide an initial framework associated with conference implementation as it pertains to complication prevention. METHODS: Team members' time spent on conference preparation, presentation, and follow-up tasks was recorded and averaged to determine the time required to prepare and present one patient. Using 2022 hourly wage rates based on our urban hospital setting, wage values were calculated for each personnel type and applied to their time spent. The total cost of the conference was annualized and calculated from the time spent in the three phases of the conference multiplied by the wage rate. Published data on complication rates and associated costs before and after conference implementation were used to calculate total cost reduction. RESULTS: With 3 active spine surgeons and 108 patients per year, the total time investment was 104.04 min per patient, costing $21,791 annually. Total RN equivalent value per patient was 5.25 for all three phases. Using a historical model, this multidisciplinary approach for adult spinal deformity reduced complications by 51% at 30 days, resulting in cost savings of $418,518 per year. Thus, the model demonstrates that implementation of this approach resulted in a potential total savings of $396,726/year. CONCLUSION: Implementing a cost-saving tool for managing complex spinal disorders is a responsibility of the spine team, who should lead a multidisciplinary conference. The combination of TDABC and lean methodology can effectively demonstrate the variable costs associated with this multidisciplinary effort and models provide evidence of potential cost-savings when applied to a multidisciplinary adult spinal deformity conference. These findings should encourage clinicians and administrators to allocate resources to improve patient care by reducing complications and costs.

Personalized Medicine in Orthopaedic Surgery: The Case of Spine Surgery.

Personalized medicine has made a tremendous impact on patient care. Although initially, it revolutionized pharmaceutical development and targeted therapies in oncology, it has also made an important impact in orthopaedic surgery. The field of spine surgery highlights the effect of personalized medicine because the improved understanding of spinal pathologies and technological innovations has made personalized medicine a key component of patient care. There is evidence for several of these advancements to support their usage in improving patient care. Proper understanding of normative spinal alignment and surgical planning software has enabled surgeons to predict postoperative alignment accurately. Furthermore, 3D printing technologies have demonstrated the ability to improve pedicle screw placement accuracy compared with free-hand techniques. Patient-specific, precontoured rods have shown improved biomechanical properties, which reduces the risk of postoperative rod fractures. Moreover, approaches such as multidisciplinary evaluations tailored to specific patient needs have demonstrated the ability to decrease complications. Personalized medicine has shown the ability to improve care in all phases of surgical management, and several of these approaches are now readily available to orthopaedic surgeons.

Incidence, etiology and time course of delays to adult spinal deformity surgery: a single-center experience.

PURPOSE: We sought to determine the incidence, origin, and timeframe of delays to adult spinal deformity surgery so that institutions using preoperative multidisciplinary patient assessment teams might better anticipate and address these potential delays. METHODS: Complex spine procedures for treatment of adult spinal deformity from 1/1/18 to 8/31/21 were identified. Procedures for infection, tumor, and urgent/emergent cases were excluded. Operations delayed due to COVID or those that were performed outside of our established perioperative care pathway were also excluded. The electronic health record was used to identify the etiology and timeline of all pre- and peri-operative delays. RESULTS: Of 235 patients scheduled for complex spine surgery, 193 met criteria for inclusion. Of these patients, 35 patients experienced a surgical delay (18.1%) with a total of 41 delays recorded. Reasons for delay include medically unoptimized (25.6%), intraoperative complication (17.9%), patient directed delay (17.9%), patient illness/injury (15.4%), scheduling complication (10.3%), insurance delay/denial (5.1%), and unknown (2.6%). Twenty-four delays experienced by 22 individuals occurred within 7 days of their scheduled surgery date. CONCLUSION: At a single multidisciplinary center, most delays to adult spinal deformity surgery occur before a patient is admitted to the hospital, and for recommendations of additional medical workup/clearance. We suspect that the preoperative protocol might increase pre-admission delays for unoptimized patients, as the protocol is intended to ensure patients receive surgery only when they are medically ready. Further research is needed to determine the economic and system impact of delays related to a preoperative optimization protocol weighed against the reduction in adverse events these protocols can provide.

Native valve endocarditis caused by Mycobacterium fortuitum in a patient of carcinoma breast.

We report an unusual case of native mitral valve endocarditis in a patient with carcinoma breast in remission. She presented with intermittent fever for 4 weeks. The patient had a chemo port in situ. Blood cultures flagged positive on the 3rd day of incubation. Staining revealed branching acid-fast bacilli, which were subsequently identified as Mycobacterium fortuitum using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. The patient responded well to medical management alone. Only two such cases have been reported from India previously.

Representativeness of the American Spine Registry: a comparison of patient characteristics with the National Inpatient Sample.

OBJECTIVE: The American Spine Registry (ASR) is a collaborative effort between the American Academy of Orthopaedic Surgeons and the American Association of Neurological Surgeons. The goal of this study was to evaluate how representative the ASR is of the national practice with spinal procedures, as recorded in the National Inpatient Sample (NIS). METHODS: The authors queried the NIS and the ASR for cervical and lumbar arthrodesis cases performed during 2017-2019. International Classification of Diseases, 10th Revision and Current Procedural Terminology codes were used to identify patients undergoing cervical and lumbar procedures. The two groups were compared for the overall proportion of cervical and lumbar procedures, age distribution, sex, surgical approach features, race, and hospital volume. Outcomes available in the ASR, such as patient-reported outcomes and reoperations, were not analyzed due to nonavailability in the NIS. The representativeness of the ASR compared to the NIS was assessed via Cohen's d effect sizes, and absolute standardized mean differences (SMDs) of < 0.2 were considered trivial, whereas > 0.5 were considered moderately large. RESULTS: A total of 24,800 arthrodesis procedures were identified in the ASR for the period between January 1, 2017, and December 31, 2019. During the same time period, 1,305,360 cases were recorded in the NIS. Cervical fusions comprised 35.9% of the ASR cohort (8911 cases) and 36.0% of the NIS cohort (469,287 cases). The two databases presented trivial differences in terms of patient age and sex for all years of interest across both cervical and lumbar arthrodeses (SMD < 0.2). Trivial differences were also noted in the distribution of open versus percutaneous procedures of the cervical and lumbar spine (SMD < 0.2). Among lumbar cases, anterior approaches were more common in the ASR than in the NIS (32.1% vs 22.3%, SMD = 0.22), but the discrepancy among cervical cases in the two databases was trivial (SMD = 0.03). Small differences were illustrated in terms of race, with SMDs < 0.5, and a more significant discrepancy was identified in the geographic distribution of participating sites (SMDs of 0.7 and 0.74 for cervical and lumbar cases, respectively). For both of these measures, SMDs in 2019 were smaller than those in 2018 and 2017. CONCLUSIONS: The ASR and NIS databases presented a very high similarity in proportions of cervical and lumbar spine surgeries, as well as similar distributions of age and sex, and distribution of open versus endoscopic approach. Slight discrepancies in anterior versus posterior approach among lumbar cases and patient race, and more significant discrepancies in geographic representation were also identified, yet decreasing trends in differences suggested the improving representativeness of the ASR over the course of time and its progressive growth. These conclusions are important to underline the external validity of quality investigations and research conclusions to be drawn from analyses in which the ASR is used.

Use of Cannulated Reamers to Facilitate Thoracic Diskectomy Using a Minimally Invasive Retropleural Thoracotomy Approach-Surgical Technique.

BACKGROUND: The surgical treatment of symptomatic thoracic disk herniations is technically challenging. In the past decade, a minimally invasive retropleural thoracotomy approach has become more popular to treat this pathology. However, efficient bone removal to safely perform the diskectomy and spinal cord decompression is difficult with this technique because of the small incision size and long working distance in the thoracic cavity and the proximity of the compressed thoracic cord. OBJECTIVE: To describe a novel surgical technique for performing a thoracic diskectomy using a minimally invasive lateral approach using cannulated reamers to facilitate bone removal. METHODS: This technique was used in 7 consecutive patients who presented with thoracic myelopathy from a thoracic disk herniation. First, a standard lateral minimally invasive retropleural approach to the thoracic spine was performed. Partially threaded guide wires were placed in the posterior aspect of the vertebral bodies adjacent to the affected disk space, and sequential cannulated reamers were passed over the guidewires to perform partial corpectomies. The posterior annulus, posterior longitudinal ligament, and herniated disk material were then resected using Penfield dissectors and Kerrison rongeurs to complete the decompression. RESULTS: All 7 patients who underwent thoracic diskectomy using this approach had stable or improved neurologic function postoperatively. There were no complications related to the use of the cannulated reamer technique. CONCLUSION: The use of cannulated reamers provides a simple and efficient method for safe bone removal to facilitate minimally invasive thoracic diskectomy using a lateral approach. This is an easily reproducible technique using commonly available equipment.

Establishing a Reference Procedure Length for Anterior Cervical Fusions: The Role for Standards in Surgical Process Improvement.

Surgical process improvement strategies are increasingly being applied to specific procedures to improve value. A critical step in any process improvement strategy is the identification of performance benchmarks. Procedure length is a performance benchmark for anterior cervical discectomy and fusion (ACDF) procedures; therefore, we sought to establish reference procedure lengths for 1-level, 2-level, and 3-level ACDFs at both teaching and non-teaching institutions and to describe methods for using this information to advance surgical process improvement initiatives. We performed a retrospective analysis of consecutive ACDFs performed at a resident teaching institution (RT) and a non-teaching institution (NT) for all 1-level, 2-level, and 3-level ACDFs. Mean case lengths and patient outcomes were calculated for individual surgeons and institutions. After limiting cases to 1-level, 2-level, and 3-level ACDFs and applying all exclusion criteria, 991 cases at the RT institution and 131 cases at the NT institution (a total of 1122 cases) were available for analysis. The mean (SD) procedure length for 1-level, 2-level, and 3-level ACDFs at the RT versus NT institutions were 121.9 min (36.3 min) and 73.6 min (29.7 min) (p<0.001), 172.7 min (44.8 min) and 112.0 min (43.0 min) (p<0.001), and 218.3 min (54.9 min) and 167.6 min (54.2 min) (p<0.001), respectively. Thirty-day outcomes were the same between institutions, except that the RT institution had a shorter mean hospital length of stay for 2-level ACDFs (1.6 days versus 2.9 days, p=0.001). This study is the first to attempt to establish a standard reference procedure length for 1-level, 2-level, and 3-level ACDFs. These data can guide efforts in surgical process improvement.

Combining time-driven activity-based costing and lean methodology: an initial study of single-level lumbar fusion surgery to assess value-based healthcare in patients undergoing spine surgery.

OBJECTIVE: Measuring costs across entire episodes of care, time-driven activity-based costing (TDABC) has recently been described as a novel cost accounting arm of value-based care organizations. Lean methodology is a system used to understand pathways of care at a granular level, allowing for standardization. The current work presents an attempt at combining the 2 methodologies to detect meaningful variation in a patient's care following single-level spine fusion. The objective of this study was to evaluate the combination of TDABC and lean methodologies in detecting meaningful variability in time-based care in patients undergoing single-level spine fusion surgery. METHODS: This study is a consecutive case series of patients who underwent single-level spine fusion performed by 1 of 5 fellowship-trained spine surgeons. Patients were diagnosed with either lumbar stenosis or spondylolisthesis. Additional inclusion criteria included inpatient stays from 1 to 3 days, discharge to home, and no readmission within 30 days of surgery. Patient demographic data were obtained. Time spent on activities for each personnel role was aggregated in 15-minute increments occurring preoperatively, intraoperatively, and postoperatively. Patients were analyzed in 3 groups based on the duration of their in-hospital stay. RESULTS: Patients discharged on postoperative day (POD) 3 had statistically significantly more total time spent than those discharged on POD 2. Patients discharged on POD 1 had less total time than those in the former 2 groups. The amount of time spent with patients did not differ for personnel in either preoperative or postanesthesia care unit phases of care. There was a statistically significant difference in time spent in surgery for surgeons, anesthesia attendings, circulators, and scrub technicians. CONCLUSIONS: In a healthcare setting run by lean methodology, TDABC may detect meaningful variability in an episode of care for single-level spine fusion. Clinicians and administrators can use this combination to allocate costs appropriately, optimize value care streams, and help improve patient care.