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.

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.

The Virtual Spine Examination: Telemedicine in the Era of COVID-19 and Beyond.

STUDY DESIGN: Narrative review. OBJECTIVES: Describe a comprehensive spine telemedicine examination. METHODS: We discuss telemedicine examination techniques for commonly encountered spine conditions. RESULTS: Techniques to evaluate gait, the cervical spine, the lumbar spine, adult spinal deformity patients, and adolescent scoliosis patients via telemedicine are described. We review limitations of the spine telemedicine examination and discuss special considerations such as patient safety and criteria for in-person assessment. CONCLUSIONS: While there are limitations to the spine telemedicine examination, unique strategies exist to provide important information to the examiner. Efforts have already been undertaken to validate and expand the capabilities of the spine telemedicine examination.

Representative dynamic ranges of spinal alignment during gait in patients with mild and severe adult spinal deformities.

BACKGROUND CONTEXT: Surgical correction strategies for adult spinal deformity (ASD) relies heavily on radiographic alignment goals, however, there is often debate regarding degree of correction and how static alignment translates to physical ability in daily life. Kinematic analysis has the potential to improve the concept of ideal spinal alignment by providing clinically meaningful estimates of dynamic changes in spinal alignment during activities of daily life. PURPOSE: Estimate representative dynamic ranges of spinal alignment during gait among ASD patients using 3D motion tracking; compare dynamic alignment between mild and severe deformity patients and to healthy adults. STUDY DESIGN/SETTING: Retrospective review at a single institution. PATIENT SAMPLE: Fifty-two ASD patients and 46 healthy adults. OUTCOME MEASURES: Radiographic alignment, kinematic spine motion, spatiotemporal gait measures, patient reported outcomes (VAS pain, ODI, SRS-22r). METHODS: Spinal alignment was assessed radiographically and during standing and overground walking tests. Dynamic alignment was initialized by linking radiographic alignment to kinematic alignment during standing and at initial heel contact during gait. Dynamic changes in maximums and minimums during gait were made relative to initial heel contact for each gait cycle. Total range-of-motion (RoM) was measured for both ASD and healthy subjects. Dynamic alignment measures included coronal and sagittal vertical axes (CVA, SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), and pelvic tilt (PT). ASD patient's deformities were classified as either Mild or Severe based on the SRS-Schwab ASD classification. RESULTS: Severe ASD patients had significantly larger dynamic maximum and minimums for SVA, TPA, LL, and PT (all p<.05) compared with Mild ASD patients. ASD patients exhibited little difference in dynamic alignment compared with healthy subjects. Only PT had a significant difference in dynamic RoM compared with healthy (p<.001). CONCLUSIONS: Mild and Severe ASD patients exhibited similar global dynamic alignment measures during gait and had comparable RoM to healthy subjects except with greater PT and reduced spatiotemporal performance which may be key compensatory mechanisms for dynamic stabilization.

Robotic-Assisted Pedicle Screw Placement During Spine Surgery.

Preoperative planning software and a robotic device facilitate the placement of pedicle screws, especially in patients with difficult anatomy, thereby increasing the feasibility, accuracy, and efficiency of the procedure. The robot functions as a semiactive surgical assistive device whose goal is not to substitute but to offer the surgeon a set of versatile tools that can broaden his or her ability to treat patients1. DESCRIPTION: The robotic guidance system consists of a bed-mounted surgical arm and a workstation. We used the Mazor X Stealth Edition Robotic Guidance System by Medtronic for spine surgery, which has been previously described2-5. Unlike other systems that are navigation-based and require an optical tracking mechanism, this system relies on the preoperative plan to be referenced using the intraoperative registration. The workstation runs an interface software that facilitates preoperative planning, intraoperative image acquisition and registration, kinematic calculations, and real-time robot motion control. The robotic arm is mounted onto the bed as well as rigidly attached to the patient's spine. It can move in 6 degrees of freedom to provide the preplanned screw trajectory and entry point thereby allowing the surgeon to manually perform the drilling and screw insertion through either an open or percutaneous procedure by first seating a drill tube and then drilling and tapping the hole as needed. ALTERNATIVES: Other robotic systems include the ROSA robot by Medtech, the ExcelsiusGPS robot by Globus Medical, and the SurgiBot and ALF-X Surgical Robotic systems (both from TransEnterix). The Da Vinci Surgical System (Intuitive Surgical) has been utilized for laparoscopic anterior lumbar interbody fusion (ALIF), but it has not been approved by the U.S. Food and Drug Administration for actual spinal instrumentation. Alternative surgical techniques for pedicle screw placement include the freehand fluoroscopy-guided technique and intraoperative image-assisted computer navigation techniques, including isocentric C-arm (Iso-C) 3D (3-dimensional) navigation (Siemens), computed tomography (CT) navigation, O-arm navigation (Medtronic), CT-magnetic resonance imaging co-registration technology, and a 3D-visual guidance technique6-8. RATIONALE: The robotic-guided pedicle screw placement offers the following benefits over conventional dorsal instrumentation techniques: improved accuracy and safety in pedicle screw insertion2-4,9-13; precision in screw size selection and planned screw positioning2; a reduction in exposure to radiation for the surgeon, the patient, and the operating-room staff9,11,12,14-19; simplicity and user-friendliness with a moderate learning curve10,11,20,21; ease of registration and reduction of operating time2; significant enhancement of the surgeon's ergonomics and dexterity for repetitive tasks in pedicle screw placement15,22-24; and a wider coverage in function to include utilization during minimally invasive surgery where applicable11,25. EXPECTED OUTCOMES: Accuracy rates between 94.5% and 99%, comparable with those in our study10, have been reported with the robotic-guided pedicle screw insertion technique, even in studies involving complex deformities and revision surgeries for congenital malformations, degenerative disorders, destructive tumors, and trauma2-4,9-13. The safety of this technique, in terms of reduced complications and intraoperative radiation exposure, has also been documented as higher than that for freehand fluoroscopic guidance or other navigation techniques9,11,12,14-19. The feasibility of this procedure has been further extended to minimally invasive procedures and to use in the cervical region, with replication of its advantages. It is associated with a reasonable learning curve, with consistent successful results after 25 to 30 patients. IMPORTANT TIPS: The principles of robotic-guided pedicle screw placement are similar irrespective of the system used.Although initially utilized mainly for thoracolumbar pedicle screw insertion, the latest robots and software have been adapted for use in the cervical spine with equivalent efficiency and accuracy.Robotic guidance can be employed in non-pedicle-screw-insertion procedures.Challenges include radiation exposure, trajectory failure, equipment and software failure, failed registration, logistics, time, and high cost.

Kinematic comparison of the use of walking sticks versus a rolling walker during gait in adult degenerative scoliosis patients.

STUDY DESIGN: A repeated-measurement, single-center, prospective study. OBJECTIVE: To compare the spatiotemporal and kinematic data using gait analysis in adult degenerative scoliosis (ADS) patients using walking sticks (WS) versus rolling walkers (RW). ADS patients undergo compensatory changes that can result in an altered gait pattern. RW are frequently prescribed, but result in a forward flexed kyphotic posture during ambulation. Gait using WS allows for more upright alignment in ADS patients. METHODS: Fifty-three ADS patients with symptomatic degenerative scoliosis performed over-ground walking at self-selected speed with WS and with a RW. Trunk and lower extremity angles along with spatiotemporal parameters were measured and compared. RESULTS: When using WS, patients exhibited less flexion at the head (WS: - 4.8° vs. RW: 11.0°, p = 0.001), and lumbar spine (WS: - 0.9° vs. RW: 4.2°, p = 0.001); while there was significantly more extension, of the cervical spine (WS: - 1.6° vs. RW: - 7.4°, p = 0.002) when using the RW. At the initial contact phase of gait, patients using WS showed decreased flexion at the ankle (WS 0.7° vs. RW: 3.8°, p = 0.018), knee (WS: 0.3° vs. RW: 4.8°, p = 0.001), hip (WS: 22.6° vs. RW: 27.3°, p = 0.001), and pelvis (WS: 10.2° vs. RW: 14.8°, p = 0.001). In contrast, the use of WS resulted in slower ambulation (WS: 0.6 m/s vs. RW: 0.7 m/s, p = 0.001). CONCLUSIONS: In ADS patients who have not undergone surgical correction, the use of WS resulted in a more upright posture, which may be more beneficial to the compensatory changes that lead to gait disturbance in ADS patients. Ambulation using WS resulted in slower gait versus a RW, due to the momentum induced by the forward flexed posture when using a RW. We recommend the use of WS for patients with ADS as it improves gait kinematics and may be a safer option.

The Correlation of Spinopelvic Parameters With Biomechanical Parameters Measured by Gait and Balance Analyses in Patients With Adult Degenerative Scoliosis.

STUDY DESIGN: A prospective cohort study. OBJECTIVE: The objective of this study was to establish the correlation between radiographic spinopelvic parameters with objective biomechanical measures of function in patients with adult degenerative scoliosis (ADS). SUMMARY OF BACKGROUND DATA: Gait and balance analyses can provide an objective measure of function. Patients with ADS demonstrate altered gait and balance patterns. Spinopelvic parameters are commonly used by clinicians to evaluate patients with ADS. However, to the best of our knowledge, no studies have examined the correlation between patients' radiographic spinopelvic parameters and biomechanical gait and balance parameters. PATIENT SAMPLE: Forty-four patients with symptomatic ADS who have been deemed, appropriate surgical candidates. METHODS: Radiographic spinopelvic parameters (CVA: central vertical axis, SVA: sagittal vertical axis, Cobb angle, PI-LL mismatch: pelvic incidence lumbar lordosis mismatch, and T1PA: T1 pelvic angle) were obtained the week before surgery. Then, gait and functional balance analyses (spatiotemporal parameters, center of mass, and head sway parameters) were performed on the same day. Correlations were determined between the radiographic spinopelvic parameters and biomechanical gait and balance parameters using Pearson product correlation. RESULTS: Our results show that patients with higher Cobb angle and CVA tend to walk slower (r=-0.494, P<0.05). Furthermore, the higher the Cobb angle (r=0.396), CVA (r=0.412), SVA (r=0.440), and PI-LL mismatch (r=0.493), the more time ADS patients spend with their feet planted during single and double support phases of gait (P<0.05). In addition, patients with a higher Cobb angle, CVA, SVA, PI-LL mismatch, and T1PA, exhibited more trunk sway, increased lower extremity neuromuscular activity, and decreased spine neuromuscular activity (0.331

Cost and Clinical Outcome of Adolescent Idiopathic Scoliosis Surgeries-Experience From a Nonprofit Community Hospital.

BACKGROUND: Recognition of the variables that drive the cost of adolescent idiopathic scoliosis (AIS) surgeries will help physicians and hospitals to initiate cost-effective measures. The purpose of this study is to analyze the hospital costs and clinical outcome for AIS surgeries. METHODS: A total of 6417 individual hospital costs and charges for 42 consecutive AIS surgeries were reviewed. The patients' demographic, surgical, and radiographic data were recorded. The costs were categorized. The relationships between total costs, categorized costs, and the independent variables were analyzed. Perioperative and postoperative complications were reviewed. Back pain, leg pain, and Oswestry Disability Index scores were obtained. RESULTS: The patients' mean age was 15 years, and 37 patients were female. Their mean main curve measured 55°. A total of 39 patients had posterior-only procedures, and 3 patients had anterior/posterior procedures. The average number of levels fused was 8. The mean hospital charge was $126,284 (range, $76,171-$215,516). The mean hospital cost was $44,126 (range, $23,205-$74,302). The average hospital stay was 5 days, with an average cost per day of $8825. The largest contributors to the overall hospital cost were spinal implants (31%), and surgery department labor cost (23%). Other categoric cost contributors included medical/surgical bed (19%), central supply/operating room supplies (9%), intensive care unit (6%), bone graft (3%), and others. No complications or revision surgeries occurred in these patients. For patients who had back and/or leg pain preoperatively, their back pain visual analog scale scores improved 1.8 points (4.5 versus 2.7 points, P < .05) and their leg pain visual analog scale scores improved 1.5 points (2.1 versus 0.6 points, P < .05). Their Oswestry Disability Index scores improved 6.1 points (17.3 versus 11.2 points, P > 0.05). CONCLUSIONS: The hospital cost for AIS surgeries is significant, with spinal implants and surgery department labor being the largest contributors. These are also areas for potential cost-effective measures.

Giant cell tumor of the thoracic spine in a 30-year-old woman.

Giant cell tumor (GCT) of the spine is a rare, benign tumor. Patients typically present with pain and also may experience neurologic deficits from spinal cord and/or nerve root compression. This article describes a patient who presented with acute mid-back pain, was diagnosed with spinal GCT through biopsy, and was treated successfully with surgical resection and instrumentation.

A Comparison of Muscular Activity During Gait Between Walking Sticks and a Walker in Patients With Adult Degenerative Scoliosis.

STUDY DESIGN: A repeated measurement, single-center, prospective study. OBJECTIVE: The purpose of this study is to compare and contrast the benefits of walking sticks versus a walker on the trunk and lower extremity muscular control in patients with adult degenerative scoliosis (ADS). SUMMARY OF BACKGROUND DATA: ADS patients demonstrate an altered gait pattern. Walking aids help maintain mobility in those patients. Whereas a walker forces patients into kyphosis, the higher grips of walking sticks allows for more upright posture, arm swing, and improved sagittal alignment. METHODS: Twenty ADS patients with symptomatic degenerative scoliosis performed over-ground walking at self-selected speed under 3 testing conditions: 1) with walking sticks (WS); 2) with walker (WR); and 3) without any device (ND). Trunk and lower extremity peak muscle activation, time to peak muscle activity, muscle duration, muscle onset, and integrated electromyography (iEMG) were measured and compared. RESULTS: The use of WS produced increases in muscle activity in the external oblique (WS: 44.3% vs. WR: 7.4% of submaximum voluntary contraction [sMVC], p = .007) and medial gastrocnemius (WS: 78.8% vs ND: 43.7% of sMVC, p = .027) in comparison to the walker and no device, respectively. When using WS, shorter muscle activity time was observed for rectus femoris (WS: 62.9% vs. WR: 88.8% of gait cycle, p = .001), semitendinosus (WS: 64.3% vs. WR: 93.0% of gait cycle, p = .003), tibialis anterius (WS: 59.4% vs. WR: 85.1% of gait cycle, p = .001), and medial gastrocnemius (WS: 67.3% vs. WR: 98.0% of gait cycle, p = .006) in comparison to the walker. CONCLUSIONS: The use of walking sticks can potentially promote trunk and lower extremity neuromuscular control and gait mechanics comparable to gait without any assistive devices. Although the differences in magnitudes between comparisons were small and should be cautiously interpreted on a case-by-case basis, based on this study's results and our anecdotal experience treating patients with ADS, we recommend the use of walking sticks to assist with their gait prior to and after surgical intervention. LEVEL OF EVIDENCE: Level III.