Randomized Trial of Augmented Pelvic Fixation in Patients Undergoing Thoracolumbar Fusion for Adult Spine Deformity: Initial Results from a Multicenter Randomized Trial.

BACKGROUND: The optimal configuration for spinopelvic fixation during multilevel spine fusion surgery for adult spine deformity remains unclear. Postoperative sacroiliac (SI) joint pain, S2AI screw loosening and implant breakage could be related to continued motion of the SI joint with use of only a single point of fixation across the SI joint. METHODS: Prospective, international, multicenter randomized controlled trial of 222 patients with adult spine deformity scheduled for multilevel (4 or more levels) spine fusion surgery with pelvic fixation. Subjects were randomized to sacroalar (S2) iliac (S2AI) screws alone for pelvic fixation or S2AI + triangular titanium implants placed cephalad to S2AI screws. Quad rod techniques were not allowed or used. Baseline spinal deformity measures were read by an independent radiologist. Site-reported perioperative adverse events were reviewed by a clinical events committee. Quality of life questionnaires and other clinical outcomes are in process with planned 2-year follow-up. RESULTS: One hundred thirteen participants were assigned to S2AI and 109 to S2AI + titanium triangular implants (TTI). 35/222 (16%) of all subjects had a history of SI joint pain or were diagnosed with SI joint pain during preoperative workup. Three-month follow-up was available in all but 4 subjects. TTI placement was successful in 106 of 109 (98%) subjects assigned to TTI. In 2 cases, TTI could not be placed due to anatomical considerations. Three TTI ventral iliac breaches were observed, all of which were managed non-surgically. One TTI subject had a transverse sacral fracture and 1 TTI subject had malposition of the implant requiring removal. CONCLUSIONS: SI joint pain is common in patients with adult spinal deformity who are candidates for multilevel spine fusion surgery. Concurrent placement of TTI parallel to S2AI screws during multilevel spine fusion surgery is feasible and safe. Further follow-up will help to determine the clinical value of this approach to augment pelvic fixation.

Catastrophic acute failure of pelvic fixation in adult spinal deformity requiring revision surgery: a multicenter review of incidence, failure mechanisms, and risk factors.

OBJECTIVE: There are few prior reports of acute pelvic instrumentation failure in spinal deformity surgery. The objective of this study was to determine if a previously identified mechanism and rate of pelvic fixation failure were present across multiple institutions, and to determine risk factors for these types of failures. METHODS: Thirteen academic medical centers performed a retrospective review of 18 months of consecutive adult spinal fusions extending 3 or more levels, which included new pelvic screws at the time of surgery. Acute pelvic fixation failure was defined as occurring within 6 months of the index surgery and requiring surgical revision. RESULTS: Failure occurred in 37 (5%) of 779 cases and consisted of either slippage of the rods or displacement of the set screws from the screw tulip head (17 cases), screw shaft fracture (9 cases), screw loosening (9 cases), and/or resultant kyphotic fracture of the sacrum (6 cases). Revision strategies involved new pelvic fixation and/or multiple rod constructs. Six patients (16%) who underwent revision with fewer than 4 rods to the pelvis sustained a second acute failure, but no secondary failures occurred when at least 4 rods were used. In the univariate analysis, the magnitude of surgical correction was higher in the failure cohort (higher preoperative T1-pelvic angle [T1PA], presence of a 3-column osteotomy; p < 0.05). Uncorrected postoperative deformity increased failure risk (pelvic incidence-lumbar lordosis mismatch > 10°, higher postoperative T1PA; p < 0.05). Use of pelvic screws less than 8.5 mm in diameter also increased the likelihood of failure (p < 0.05). In the multivariate analysis, a larger preoperative global deformity as measured by T1PA was associated with failure, male patients were more likely to experience failure than female patients, and there was a strong association with implant manufacturer (p < 0.05). Anterior column support with an L5-S1 interbody fusion was protective against failure (p < 0.05). CONCLUSIONS: Acute catastrophic failures involved large-magnitude surgical corrections and likely resulted from high mechanical strain on the pelvic instrumentation. Patients with large corrections may benefit from anterior structural support placed at the most caudal motion segment and multiple rods connecting to more than 2 pelvic fixation points. If failure occurs, salvage with a minimum of 4 rods and 4 pelvic fixation points can be successful.

Minimally Invasive Posterior Facet Decortication and Fusion Using Navigated Robotic Guidance: Feasibility and Workflow Optimization.

Minimally invasive spine surgery reduces tissue dissection and retraction, decreasing the morbidity associated with traditional open spine surgery by decreasing blood loss, blood transfusion, complications, and pain. One of the key challenges with a minimally invasive approach is achieving consistent posterior fusion. Although advantageous in all fusion surgeries, solid posterior fusion is particularly important in spinal deformity, revisions, and fusions without anterior column support. A minimally invasive surgical approach accomplished without sacrificing the quality of the posterior fusion has the potential to decrease both short- and long-term complications compared to the traditional open techniques. Innovations in navigated and robotic-assisted spine surgery continue to address this need. In this article, we will outline the feasibility of achieving posterior facet fusion using the Mazor X Stealth Edition Robotic Guidance System.

Robotic-Assisted Revision Spine Surgery.

As the surgical treatment of spinal degenerative conditions increases, more patients will ultimately require revision spine surgery. Revision spine surgery is more technically demanding than primary surgery with increased complication rates and variable clinical outcomes. The freehand placement of pedicle screws into a previously operated and/or fused level is more difficult due to the altered anatomic landmarks and/or bone loss. Additional benefit of robotic spine surgery is appreciated during such revision spine surgical procedures with unusual anatomic considerations, whereby the preoperative planning using robotic planning software and computer-assisted robotic guidance play a crucial role in assisting the surgeon to "visualize the invisible." We highlight 3 roles of this technology in 3 cases: planning strategic osteotomies, redrilling of screw holes, and insertion of revision screws in previously operated thoracolumbar and cervical spine regions.

Can Robotic Spine Surgery Become the Standard of Care?

Concerns regarding traditional techniques led to the development of robotic systems to facilitate the safe and accurate placement of pedicle screws. The Mazor Spine Assist was the first robotic spine surgery (RSS) platform to receive US Food and Drug Administration approval in 2004. Since then, there has been a steady increase in the application of RSS with several additional iterations of the Mazor platform and other competing systems receiving approval. As the indications, potential benefits, and utilization of RSS continue to expand, the question naturally arises as to whether RSS will eventually become the standard of care for spine surgery. In this article, we review the available evidence and experience with RSS and discuss the potential for RSS to become the medical standard of care.

Robotic Spine Surgery: Past, Present, and Future.

STUDY DESIGN: Systematic review. OBJECTIVE: The aim of this review is to present an overview of robotic spine surgery (RSS) including its history, applications, limitations, and future directions. SUMMARY OF BACKGROUND DATA: The first RSS platform received United States Food and Drug Administration approval in 2004. Since then, robotic-assisted placement of thoracolumbar pedicle screws has been extensively studied. More recently, expanded applications of RSS have been introduced and evaluated. METHODS: A systematic search of the Cochrane, OVID-MEDLINE, and PubMed databases was performed for articles relevant to robotic spine surgery. Institutional review board approval was not needed. RESULTS: The placement of thoracolumbar pedicle screws using RSS is safe and accurate and results in reduced radiation exposure for the surgeon and surgical team. Barriers to utilization exist including learning curve and large capital costs. Additional applications involving minimally invasive techniques, cervical pedicle screws, and deformity correction have emerged. CONCLUSION: Interest in RSS continues to grow as the applications advance in parallel with image guidance systems and minimally invasive techniques. IRB APPROVAL: N/A.

Robotic-guided placement of cervical pedicle screws: feasibility and accuracy.

INTRODUCTION: It has been shown that pedicle screw instrumentation in the cervical spine has superior biomechanical pullout strength and stability. However, due to the complex and variable anatomy of the cervical pedicles and the risk of catastrophic complications, cervical pedicle screw placement is not widely utilized. STUDY DESIGN: A retrospective, consecutive patient review. OBJECTIVE: To review and report our experience with robotic guided cervical pedicle screw placement. METHODS: We retrospectively reviewed preoperative and postoperative CT scans of 12 consecutive patients who underwent cervical pedicle screw fixation with robotic guidance. Screw placement and deviation from the preoperative plan were assessed using the robotic system's planning software by fusing the preoperative CT (with the planned cervical pedicle screws) to the post-op CT. This process was carried out by manually aligning the anatomical landmarks on the two CTs. Once a satisfactory fusion was achieved, the software's measurement tool was used manually to compare the planned vs. actual screw placements in the axial, sagittal and coronal planes within the instrumented pedicle in a resolution of 0.1 mm. Medical charts were reviewed for technical issues and intra-operative complications. RESULTS: Eighty-eight cervical pedicle screws were reviewed in 12 patients; mean age = 65 years, M:F = 2:1, and mean BMI = 27.99. No intra-operative complications related to the cervical pedicle screw placement were reported. Robotic guidance was successful in all 88 screws: eight in C2, 14 in C3, 16 in each of C4 and C5, 19 in C6, and 15 at C7. There were 14 pedicle screw breaches (15.9%); all were medial, less than 1 mm, and with no clinical consequences. In the axial plane, the screws deviated from the preoperative plan by 1.32 ± 1.17 mm and in the sagittal plane by 1.27 ± 1.00 mm. In the trajectory view, the overall deviation was 2.20 ± 1.17 mm. Although differences were observed in screw deviation from the pre-op plan between the right and left sides, they were not statistically significant (p > 0.05). CONCLUSION: This study indicates that robotic-guided cervical pedicle screw placement is feasible and safe. The medial breaches did not result in any clinical consequences.

Spine Patient Satisfaction With Telemedicine During the COVID-19 Pandemic: A Cross-Sectional Study.

STUDY DESIGN: Original research, cross-sectional study. OBJECTIVES: Evaluate patient satisfaction with spine care delivered via telemedicine. Identify patient- and visit-based factors associated with increased satisfaction and visit preference. METHODS: Telemedicine visits with a spine surgeon at 2 practices in the United States between March and May 2020 were eligible for inclusion in the study. Patients were sent an electronic survey recording overall satisfaction, technical or clinical issues encountered, and preference for a telemedicine versus an in-person visit. Factors associated with poor satisfaction and preference of telemedicine over an in-person visit were identified using multivariate logistic regression. RESULTS: A total of 772 responses were collected. Overall, 87.7% of patients were satisfied with their telemedicine visit and 45% indicated a preference for a telemedicine visit over an in-person visit if given the option. Patients with technical or clinical issues were significantly less likely to achieve 5 out of 5 satisfaction scores and were significantly more likely to prefer an in-person visit. Patients who live less than 5 miles from their surgeon's office and patients older than 60 years were also significantly more likely to prefer in-person visits. CONCLUSIONS: Spine telemedicine visits during the COVID-19 pandemic were associated with high patient satisfaction. Additionally, 45% of respondents indicated a preference for telemedicine versus an in-patient visit in the future. In light of these findings, telemedicine for spine care may be a preferable option for a subset of patients into the future.

Minimally Invasive Robotic Lumbar Facet Decortication.

Minimally invasive percutaneous pedicle screws (PPS) are placed through muscle sparing paramedian incisions and provide rigid 3 column fixation to promote stability and fusion. Percutaneous pedicle instrumentation is generally performed as adjunctive posterior stabilization after anterior lumbar interbody fusion or lateral lumbar interbody fusion procedures. In these instances, arthrodesis is often achieved through the interbody fusion rather than posterior column fusion. In some cases, the surgeon may choose to perform posterior facet fusion in addition to PPS and anterior interbody. The addition of a minimally invasive facet fusion to PPS and anterior column interbody fusion creates more fusion surface and enables a truly circumferential fusion. While robotic-guided facet decortication has been suggested, there are currently no published techniques. Here, we describe a novel minimally invasive technique to perform percutaneous robotic facet decortication in conjunction with PPS following anterior lumbar interbody fusion or lateral lumbar interbody fusion.

Robotic Sacroiliac Fixation Technique for Triangular Titanium Implant in Adult Degenerative Scoliosis Surgery: 2-Dimensional Operative Video.

Corrective surgery remains a definitive treatment for adult spinal deformity, improving pain and disability. With these cases, instrumentation to the pelvis with iliac fixation is recommended. Whether iliac or S2-Alar-Iliac (S2AI) trajectories are used, sacroiliac joint pain and long-term sacroilitis can be common after long-fusion constructs.1-3 Sacroiliac fusion with triangular titanium implants during fusion can reduce back pain associated with sacroiliac joint degeneration,3 provides reduction in sacroiliac joint motion and stress when added to S2AI screws, and potentially enhances mechanical stability of fusion constructs.4 Here, we present a technique for placing triangular titanium sacroiliac implants (iFuse BedrockTM; SI-BONE Inc, Santa Clara, California) alongside S2AI screws using a robotic platform (Mazor X; Medtronic Sofamor Danek, Medtronic Inc, Dublin, Ireland). Navigated robotics allows reduction in human error with implant placement, and potentially decreased operative time/fluoroscopy.5-7 Key surgical steps include placement of K wires for S2AI and bilateral SI-implants, tapping, replacing SI-implant K wires with guide pins, placing S2AI screws, and finally placing the SI-implant. Final placement is verified with intraoperative fluoroscopy. The patient described is a 61-yr-old woman with worsening adult degenerative scoliosis, lower back pain, left leg radicular pain, and mild right leg pain who failed conservative treatment. Examination revealed diminished strength in both legs. Imaging was significant for moderate sigmoid scoliosis, discogenic disease, and osteoarthritis at all levels. She consented to undergo corrective surgery. Postoperatively, the patient experienced resolution of her leg weakness and pain. Imaging demonstrated appropriate positioning of hardware. Prospective studies on the efficacy of the SI-implant are underway.

The predictive accuracy of surgical planning using pre-op planning software and a robotic guidance system.

BACKGROUND: Navigation and robotic-guided systems are being used more often to facilitate efficient and accurate placement of hardware during spinal surgeries. Preoperative surgical planning is a key step in the safe use of these tools. No studies have yet investigated the predictive accuracy of surgical planning using a robotic guidance system. METHODS: Data were prospectively collected from patients in whom Mazor X-Align ™ [Medtronic Inc., Minneapolis, MN., USA] robotic guidance system software was used to plan their spinal instrumentation in order to achieve the best possible correction and the plans executed intraoperatively under robotic guidance. RESULTS: A total of 33 patients (26 females, 7 males) were included. Their mean age was 51 years (12-79), and their mean BMI was 23.90 (15.55-35.91). Their primary diagnoses were scoliosis (20), kyphosis (5), spondylolisthesis (4), adjacent segment degeneration (3), and metastatic tumor (1). Preoperatively, the patients' mean coronal Cobb Angle (CA) was 36.5 ± 14.4°, and their mean sagittal CA was 27.7 ± 20.0°. The mean planned correction coronal CA was 0.2 ± 1.2°, and the mean planned correction sagittal CA was 28.4 ± 16.7°. Postoperatively, the patients' mean coronal CA that was achieved was 5.8 ± 7.4°, and their mean sagittal CA was 31.0 ± 18.3°. The mean difference between the planned and achieved angles was 5.5 ± 7.4° for the coronal, and 9.03 ± 9.01° for the sagittal CA. For the thoracic kyphosis and lumbar lordosis, the mean difference between the planned and postoperatively measured values was 15.3 ± 10.8 and 12.8 ± 9.6, respectively. CONCLUSION: This study indicates that the predictive accuracy of the use of preoperative planning software and robotic guidance to facilitate the surgical plan is within 6° and 9° in the coronal and sagittal planes, respectively.

Balance effort, Cone of Economy, and dynamic compensatory mechanisms in common degenerative spinal pathologies.

BACKGROUND: Changes in balance are common in individuals with spinal disorders and may cause falls. Balance efficiency, is the ability of a person to maintain their center of gravity with minimal neuromuscular energy expenditure, oftentimes referred to as Cone of Economy (CoE). CoE balance is defined by two sets of measures taken from the center of mass (CoM) and head: 1) the range-of-sway (RoS) in the coronal and sagittal planes, and 2) the overall sway distance. This allows spine caregivers to assess the severity of a patient's balance, balance pattern, and dynamic posture and record the changes following surgical intervention. Maintenance of balance requires coordination between the central nervous and musculoskeletal systems. RESEARCH QUESTION: To discern differences in balance effort values between common degenerative spinal pathologies and a healthy control group. METHODS: Three-hundred and forty patients with degenerative spinal pathologies: cervical spondylotic myelopathy (CSM), adult degenerative scoliosis (ADS), sacroiliac dysfunction (SIJD), degenerative lumbar spondylolisthesis (DLS), single-level lumbar degeneration (LD), and failed back syndrome (FBS), and 40 healthy controls were recruited. A functional balance test was performed approximately one week before surgery recorded by 3D video motion capture. RESULTS: Balance effort and compensatory mechanisms were found to be significantly greater in degenerative spinal pathologies patients compared to controls. Head and Center of Mass (CoM) overall sway ranged from 65.22 to 92.78 cm (p < 0.004) and 35.77-53.31 cm (p < 0.001), respectively in degenerative spinal pathologies patients and in comparison to controls (Head: 44.52 cm, CoM: 22.24 cm). Patients with degenerative spinal pathologies presented with greater trunk (1.61-2.98°, p < 0.038), hip (4.25-5.87°, p < 0.049), and knee (4.55-6.09°, p < 0.036) excursion when compared to controls (trunk: 0.95°, hip: 2.97°, and knee: 2.43°). SIGNIFICANCE: The results of this study indicate that patients from a wide variety of degenerative spinal pathologies similarly exhibit markedly diminished balance (and compensatory mechanisms) as indicated by increased sway on a Romberg test and a larger Cone of Economy (CoE) as compared to healthy controls. Balance effort, as measured by overall sway, was found to be approximately double in patients with degenerative spinal pathologies compared to healthy matched controls. Clinicians can compare CoE parameters among symptomatic patients from the different cohorts using the Haddas' CoE classification system to guide their postoperative prognosis.

Functional Ability Classification Based on Moderate and Severe Kinesophobia and Demoralization Scores in Degenerative Spine Patients.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: To assess the relationship of fear avoidance and demoralization on gait and balance and determine a threshold score for the Tampa Scale for Kinesophobia (TSK) and the Demoralization Scale (DS) that identifies spine patients with gait and balance dysfunction amplified by underlying psychological factors. SUMMARY OF BACKGROUND DATA: Fear avoidance and demoralization are crucial components of mental health that impact the outcomes in spine surgery. However, interpreting their effect on patient function remains challenging. Further establishing this correlation and identifying a threshold of severity can aid in identifying patients in whom a portion of their altered gait and balance may be amplified by underlying psychologic distress. METHODS: Four hundred five symptomatic spine patients were given the TSK and DS questionnaires. Patient's gait and balance were tested with a human motion capture system. A TSK score of 41 and a DS score of 30 were chosen as thresholds to classify moderate versus severe dysfunction based on literature and statistical analysis. RESULTS: Higher TSK and DS scores were correlated with worse walking speed (P < 0.001), longer stride time (P = 0.001), decreased stride length (P < 0.048), and wider step width (<0.001) during gait as well as increased sway across planes (P = 0.001) during standing balance. When classified by TSK scores >41, patients with more severe fear avoidance had slower walking speed (P < 0.001), longer stride time (P = 0.001), shorter stride length (P = 0.004), increased step width (P < 0.001), and increased sway (P = 0.001) compared with their lower scoring counterparts. Similarly, patients with DS > 30 had slower walking speed (P = 0.012), longer stride time (P = 0.022), and increased sway (P = 0.003) compared with their lower scoring counterparts. CONCLUSION: This study demonstrates that fear avoidance and demoralization directly correlate with worsening gait and balance. Furthermore, patients with TSK > 41 and DS > 30 have more underlying psychological factors that contribute to significantly worse function compared with lower scoring peers. Understanding this relationship and using these guidelines can help identify and treat patients whose gait dysfunction may be amplified by psychologic distress.Level of Evidence: 3.

Assessing the cone of economy in patients with spinal disease using only a force plate: an observational retrospective cohort study.

STUDY DESIGN: This is a retrospective cohort with multiple regression modeling. OBJECTIVE: The aim is to develop a new method for estimating cone of economy (CoE) using a force plate rather than traditional motion capture. BACKGROUND: Currently, most spinal deformity surgeons rely on static radiographic parameters for alignment, balance, and outcomes data alongside patient-reported outcome measures. The CoE, the stable region of upright posture, can be objectively measured to determine the efficiency and balance of the spine. Motion capture technology is currently used to collect data to calculate CoE, but this requires expensive and complex equipment, which is a barrier to widespread adoption and clinical use of CoE measurements. Force plates, which measure pressure, are less expensive and can be used in a clinical setting. METHODS: Motion capture and a force plate were used to quantify the CoE of 473 subjects (423 spinal surgical candidates; 50 healthy controls; 271 females; age: 58.60 ± 15.27; height: 1.69 ± 0.13; weight: 81.07 ± 20.91), and a linear multiple regression model was used to predict CoE using force plate data in a human motion laboratory setting. Patients were required to stand erect with feet together and eyes open in their self-perceived balanced and natural position for a full minute while measures of sway and center of pressure (CoP) were recorded. RESULTS: The CoP variable regression model successfully predicted CoE measurements. The variables that were used to predict vertical CoE were CoP coronal sway, CoP sagittal sway, and CoP total sway in several combinations. The coefficient of determination for the head total sway model indicated a 87.0% correlation (F(3,469) = 1044.14, p < 0.001). The coefficient of determination for the head sagittal sway model indicated a 69.2% correlation (F(3,469) = 351.70, p < 0.001). The coefficient of determination for the head coronal sway model indicated a 85.2% correlation (F(3,469) = 899.27, p < 0001). CONCLUSION: Cone of economy was estimated from force plate data using center of pressure with high correlation without the use of motion capture in healthy controls and a variety of spine patients. This could lower the entry burden for measurement of the CoE in patients, enabling widespread use. This would provide surgeons objective global balance data, along with Haddas' CoE classification system, that could assist with surgical decision-making and facilitate objective monitoring surgical outcomes.

Validity of a pre-surgical algorithm to predict pain, functional disability, and emotional functioning 1 year after spine surgery.

Psychopathology has been associated with patient reports of poor outcome and an algorithm has been useful in predicting short-term outcomes. The objective of this study is to investigate whether a pre-surgical psychological algorithm could predict 1-year spine surgery outcome reports, including pain, functional disability, and emotional functioning. A total of 1,099 patients consented to participate. All patients underwent spine surgery (e.g., spinal fusion, discectomy, etc.). Pre-operatively, patients completed self-report measures prior to surgery. An algorithm predicting patient prognosis based on data from the pre-surgical psychological evaluation was filled out by the provider for each patient prior to surgery. Post-operatively, patients completed self-report measures at 3- and 12-months after surgery. Longitudinal latent class growth analysis (LCGA) was used to derive patient outcome groups. These outcome groups were then compared to pre-surgical predictions made. LCGA analyses derived three groups of patients from the reported outcome data (entropy = .84): excellent outcomes, good outcomes, and poor outcomes. The excellent and good groups demonstrated improvements over time, but the poor outcome groups, on some measures, reported worsening of pain, functional disability, and emotional functioning over time. The pre-surgical algorithm yielded good concordance with the statistically derived outcome groups (Kendall's W = .81). Using a pre-surgical psychological evaluation algorithm for predicting long-term spine surgery outcomes can identify patients who are unlikely to report good outcomes, and point to areas for psychological intervention that can either improve surgery results or to be utilized as alternatives to elective spine surgery. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Reporting and tracking objective functional outcome measures: implementation of a summary report for gait and balance measures.

The aim of this manuscript is to describe knowledge gaps in the literature, future directions, and emerging applications of gait and balance analysis in spine surgery with regard to functional outcomes measurement. Functional outcome measurement has been established as a useful clinical and research investigational tool in musculoskeletal disease. Evidence currently supports its use in the diagnosis, treatment, and outcome measurement of multiple musculoskeletal disease states, including spinal disease, and its usefulness continues to grow as literature develops. Gait and balance analysis has proven to be broadly applicable, but most clinicians remain unfamiliar and untrained in its usage. The logistical and communication barriers are also described with the potential solutions that are on the near horizon of research. This article describes our methodology for improving conveyance of functional outcome measures in spine surgery. Additionally, we provide a case example of an adult patient with spinal deformity who is examined pre and post operatively using our methodology.

Cone of economy classification: evolution, concept of stability, severity level, and correlation to patient-reported outcome scores.

STUDY DESIGN: A prospective cohort study OBJECTIVE: To determine a classification system for cone of economy (CoE) measurements that defines clinically significant changes in altered balance and to assess if the CoE measurements directly impacts patients reported outcome measures (PROMs). Preoperative functional data is a crucial component of determining patient disability and prognosis. The CoE has been theorized to be the foundation of biomechanical changes that leads to increased energy expenditure and disability in spine patients. PROMs have been developed to quantify the level of debilitation in spine patients but have various limitations. METHODS: A total of 423 symptomatic adult patients with spine pathology completed a series of PROMs preoperatively including VAS, ODI, Tampa Scale for Kinesiophobia (TSK), Fear and Avoidance Beliefs Questionnaire (FABQ), and Demoralization (DS). Functional balance was tested in this group using a full-body reflective marker set to measure head and center of mass (CoM) sway. RESULTS: PROMs scores were correlated with the magnitude of the CoE measurements. Patients were separated by the following proposed classification: CoM coronal sway > 1.5 cm, CoM sagittal sway > 3.0 cm, CoM total sway > 30.0 cm, head coronal sway > 3.0 cm, head sagittal sway > 6.0 cm, and head total sway > 60.0 cm. Significant differences were noted in the ODI (< 0.001), FABQ physical activity (< 0.001-0.009), DS (< 0.001-0.023), and TSK (< 0.001-0.032) across almost all planes of motion for both CoM and head sway. The ODI was most sensitive to the difference between groups across CoM and head sway planes with a mean ODI of 47.5-49.5 (p < 0.001) in the severe group versus 36.6-39.3 (p < 0.001) in the moderate group. CONCLUSIONS: By classifying CoE measurements by the cutoffs proposed, clinically significant alterations in balance can be quantified. Furthermore, this study demonstrates that across spinal pathology, higher magnitude CoE and range of sway measurements correlate with worsening PROMs. The Haddas' CoE classification system in this study helps to identify patients that may benefit from surgery and guide their postoperative prognosis.