Are We Finally Ready for Total Joint Replacement of the Spine? An Extension of Charnley's Vision.

Professor Sir John Charnley has been rightfully hailed as a visionary innovator for conceiving, designing, and validating the Operation of the Century-the total hip arthroplasty. His groundbreaking achievement forever changed the orthopedic management of chronically painful and dysfunctional arthritic joints. However, the well-accepted surgical approach of completely removing the diseased joint and replacing it with a durable and anatomically based implant never translated to the treatment of the degenerated spine. Instead, decompression coupled with fusion evolved into the workhorse intervention. In this commentary, the authors explore the reasons why arthrodesis has remained the mainstay over arthroplasty in the field of spine surgery as well as discuss the potential shift in the paradigm when it comes to treating degenerative lumbar disease.

Intrathecal Fentanyl With a Myofascial Plane Block in Open Lumbar Surgeries: A Case Series.

BACKGROUND: Acute postoperative pain control after lumbar surgery is imperative to minimizing long-term narcotic use and associated adverse sequela. The safety of intrathecal morphine for postoperative pain management in spine surgery has been investigated; however, to date, no studies have investigated the safety of intrathecal fentanyl with a myofascial plane (MP) block in lumbar procedures. OBJECTIVE: To assess the safety profile of intrathecal fentanyl with a MP block administered during lumbar surgery and the subsequent utilization of postoperative intravenous opioids. METHODS: An intraoperative intrathecal injection of fentanyl and a MP block was administered in 40 patients undergoing open lumbar reconstructive surgery. The procedure performed was an open decompression with lumbar total joint reconstruction at 1 to 3 lumbar levels. Postoperative complications including urinary retention, respiratory depression, and need for IV opioid use were recorded. RESULTS: Postoperatively, none of the study patients required IV opioid medication for supplemental pain control. Thirty-six patients (85%) were discharged same day or before 23 hours postoperatively. No intrathecal fentanyl-related perioperative complications were noted. None of the 40 listed patients experienced urinary retention or delayed respiratory depression. One patient (2%) experienced orthostatic hypotension at postoperative day 1, which resolved on discontinuation of oral oxycodone. CONCLUSION: Intrathecal fentanyl and MP block may be a safe option for perioperative pain control and may reduce the need for supplemental intravenous opioids without increased risk of respiratory depression, urinary retention, or other side effects. Further studies are necessary to compare the efficacy of intrathecal fentanyl with other analgesia techniques.

State of the art review of new technologies in spine deformity surgery-robotics and navigation.

STUDY DESIGN/METHODS: Review article. OBJECTIVES: The goal of this article is to review the available evidence for computerized navigation and robotics as an accuracy improvement tool for spinal deformity surgery, as well as to consider potential complications, impact on clinical outcomes, radiation exposure, and costs. Pedicle screw and rod construct are widely utilized for posterior spinal fixation in spinal deformity correction. Freehand placement of pedicle screws has long been utilized, although there is variable potential for inaccuracy depending on surgeon skill and experience. Malpositioned pedicle screws may have significant clinical implications ranging from nerve root irritation, inadequate fixation, CSF leak, perforation of the great vessels, or spinal cord damage. Computer-based navigation and robotics systems were developed to improve pedicle screw insertion accuracy and consistency, and decrease the risk of malpositioned pedicle fixation. The available evidence suggests that computer-based navigation and robotic-assisted guidance systems for pedicle cannulation are at least equivalent, and in several reports superior, to freehand techniques in terms of accuracy. CT and robotic navigation systems do appear to decrease radiation exposure to the operative team in some reports. Published reports do indicate longer operative times with use of robotic navigation compared with traditional freehand techniques for pedicle screw placement. To date, there is no conclusive evidence that use of CT or robotic navigation has any measurable impact on patient outcomes or overall complication reduction. There are theoretical advantages with robotic and CT navigation in terms of both speed and accuracy for severe spinal deformity or complex revision cases, however, there is a need for studies to investigate this technology in these specific cases. There is no evidence to date demonstrating the cost effectiveness of CT or robotic navigation as compared with traditional pedicle cannulation techniques. CONCLUSIONS: The review of available evidence suggests that computer-based navigation and robotic-assisted guidance systems for pedicle cannulation are at least equivalent, and in several reports superior, to freehand techniques in terms of radiographic accuracy. There is no current clinical evidence that the use of navigation or robotic techniques leads to improved patient outcomes or decreased overall complications or reoperation rates, and the use of these systems may substantially increase surgical costs. LEVEL OF EVIDENCE: V.

Surgeons lack of agreement on determining preoperative radiographic and clinical shoulder balance in adolescent and adult idiopathic scoliosis patients.

PURPOSE: Preoperative shoulder balance is an important factor in determining the upper instrumented vertebrae (UIV). In adolescent and adult idiopathic scoliosis (AIS/AdIS) patients, we studied the intraobserver and interobserver reliability of spinal surgeons' assessment of preoperative shoulder balance using X-rays (XR) and anterior/posterior photographs. METHODS: An observational review of a prospective multicenter database (AIS Lenke Type 1/5/6) and prospective single-institution database (AdIS) was conducted. Ten spine surgeons reviewed AIS cases; 12 spine surgeons reviewed AdIS cases. Surgeons rated the higher shoulder: left/right/same/unsure. Reliability was calculated using Fleiss' kappa coefficient. RESULTS: Among 145 Type 1 AIS cases, intraobserver reliability was moderate-to-substantial: XR (κ = 0.59), anterior photographs (κ = 0.68), posterior photographs (k = 0.65). Interobserver reliability was fair to moderate for XR (κ = 0.31), anterior photographs (κ = 0.20), and posterior photographs (κ = 0.30). Among 52 Type 5/6 AIS cases, intraobserver reliability was substantial: XR (κ = 0.70), anterior photographs (κ = 0.76), posterior photographs (κ = 0.71). Interobserver reliability was fair to moderate for XR (κ = 0.49), anterior photographs (κ = 0.47), and posterior photographs (κ = 0.36). Among 66 AdIS cases, intraobserver reliability was substantial: XR (κ = 0.68), anterior photographs (κ = 0.67), posterior photographs (κ = 0.69). Interobserver reliability was moderate for XR (κ = 0.45), anterior photographs (κ = 0.43), posterior photographs (κ = 0.49). Within Type 1 AIS patients, attendings had better intraobserver reliabilities compared to fellows using X-rays (κ = 0.61 vs. 0.53), yet no effect of surgeon experience was seen with clinical photographs. CONCLUSION: Though surgeons' ability to agree with themselves was moderate to substantial, surgeons' ability to agree with each other was fair to moderate. Combined measures to assess preoperative shoulder balance are needed for UIV selection.

Seated Lateral X-ray Is a Better Stress Radiograph of the Lumbar Spine Compared to Standing Flexion.

STUDY DESIGN: Prospective lumbar radiograph analysis. OBJECTIVE: To compare changes in lumbar lordosis in standing flexion versus seated lateral radiographs. METHODS: Standing lateral, standing flexion, and seated lateral X-rays of the lumbar spine were obtained in patients presenting with low back pain. Trauma, tumor, and revision cases were excluded. Changes in global lumbar as well as segmental lordosis were measured in each position. RESULTS: Seventy adult patients were reviewed. Overall, the greatest changes in lordosis were seen at L4-S1 in both the seated and flexion X-rays (12.5° and 6.3°, respectively). Greater kyphosis was seen in seated versus flexion X-rays (21.6° vs 15.8°); changes in lordosis from L1-L3 were similar in both positions, with little change seen at these levels (approximately 5° to 7°). On subgroup analysis, these differences were magnified in analyzing only patients that moved at least 20° globally, and there were no significant differences between sitting and flexion in "stiff" patients that moved less than 20° globally. CONCLUSION: Greater lumbar kyphosis was seen in the seated position compared to standing flexion, especially from L4-S1. Given these results we suggest the use of seated lateral X-rays to dynamically assess the lumbar spine. These findings may also guide future research into the mechanism and clinical relevance of a stiff versus mobile lumbar spine, as well as into the sensitivity of seated X-rays in detecting instability.

Loading of the lumbar spine during transition from standing to sitting: effect of fusion versus motion preservation at L4-L5 and L5-S1.

BACKGROUND CONTEXT: Transition from standing to sitting significantly decreases lumbar lordosis with the greatest lordosis-loss occurring at L4-S1. Fusing L4-S1 eliminates motion and thus the proximal mobile segments maybe recruited during transition from standing to sitting to compensate for the loss of L4-S1 mobility. This may subject proximal segments to supra-physiologic flexion loading. PURPOSE: Assess effects of instrumented fusion versus motion preservation at L4-L5 and L5-S1 on lumbar spine loads and proximal segment motions during transition from standing to sitting. STUDY DESIGN: Biomechanical study using human thoracolumbar spine specimens. METHODS: A novel laboratory model was used to simulate lumbosacral alignment changes caused by a person's transition from standing to sitting in eight T10-sacrum spine specimens. The sacrum was tilted in the sagittal plane while constraining anterior-posterior translation of T10. Continuous loading-data and segmental motion-data were collected over a range of sacral slope values, which represented transition from standing to different sitting postures. We compared different constructs involving fusions and motion preserving prostheses across L4-S1. RESULTS: After L4-S1 fusion, the sacrum could not be tilted as far posteriorly compared to the intact spine for the same applied moment (p<.001). For the same reduction in sacral slope, L4-S1 fusion induced 2.9 times the flexion moment in the lumbar spine and required 2.4 times the flexion motion of the proximal segments as the intact condition (p<.001). Conversely, motion preservation at L4-S1 restored lumbar spine loads and proximal segment motions to intact specimen levels during transition from standing to sitting. CONCLUSIONS: In general, sitting requires lower lumbar segments to undergo flexion, thereby increasing load on the lumbar disks. L4-S1 fusion induced greater moments and increased flexion of proximal segments to attain a comparable seated posture. Motion preservation using a total joint replacement prosthesis at L4-S1 restored the lumbar spine loads and proximal segment motion to intact specimen levels during transition from standing to sitting. CLINICAL SIGNIFICANCE: After L4-S1 fusion, increased proximal segment loading during sitting may cause discomfort in some patients and may lead to junctional breakdown over time. Preserving motion at L4-S1 may improve patient comfort and function during activities of daily living, and potentially decrease the need for adjacent level surgery.

Improvements in Neck Pain and Disability Following C1-C2 Posterior Cervical Instrumentation and Fusion for Atlanto-Axial Osteoarthritis.

OBJECTIVE: Symptomatic Atlanto-axial (C1-2) osteoarthritis (AAOA) is a common phenomenon in elderly patients; however, there is a paucity of data on the effectiveness of posterior atlanto-axial fusion (PAAF) for this condition. To this end, here we assess changes in patient-reported outcomes and neck-related disability in adult patients undergoing PAAF for symptomatic C1-2 AAOA. METHODS: In this retrospective study, the clinical records of consecutive patients with symptomatic AAOA who underwent PAAF between 2004 and 2017 were reviewed. Patient demographics, comorbidities, intraoperative and postoperative variables, and complication rates were collected. Neck Disability Index (NDI) scores were recorded at baseline and 6 weeks, 6 months, 1 year, and 2 years postoperatively. RESULTS: Forty-two patients (average age, 72.04 ± 8.56 years; 26.19% males) met the study's inclusion criteria. In this cohort, 19.04% had previous subaxial cervical spine surgery, 35.71% had a history of smoking (all had stopped smoking before surgery), and 11.90% had type II diabetes. At baseline, the majority of patients had a normal neurologic exam. The average preoperative NDI score was 26.88 ± 24.85, which improved to 10.59 ± 14.88 at the 1-year follow-up and 13.20 ± 14.96 at the 2-year follow-up (P = 0.004). At baseline, 18% of the patients reported severe disability based on NDI score; this percentage decreased to 2% at 1 year and 0 at 2 years (P = 0.01). Importantly, a high percentage (11.90%) of patients had undergone previous subaxial cervical fusion for their pain due to a mistaken diagnosis for this condition, without symptom relief. CONCLUSIONS: In appropriately selected patients, PAAF may decrease neck pain and improve functional disability in patients with AAOA. Future prospective longitudinal studies are needed to corroborate these findings.

A novel MRI-based classification of spinal cord shape and CSF presence at the curve apex to assess risk of intraoperative neuromonitoring data loss with thoracic spinal deformity correction.

STUDY DESIGN: Retrospective cohort. We present a simple classification system that is able to identify patients with increased odds of losing intraoperative neuromonitoring data during thoracic deformity correction. Type 3 spinal cords, with the cord deformed against the concave pedicle in the axial plane, have ×28 greater odds of losing monitoring data during surgery. OBJECTIVES: Assess preoperative morphology of the spinal cord across the thoracic concavity to predict intraoperative loss of neuromonitoring data. METHODS: 128 consecutive patients undergoing surgical correction of a thoracic deformity with pedicle screw/rod constructs were included. Spinal cords were classified into 3 types based on the appearance of the cord on the axial-T2 MRI at the apex of the curve. Type 1 is defined as a circular/symmetric cord with visible CSF between the cord and the apical concave pedicle/vertebral body. Type 2 is a circular/oval/symmetric cord with no visible CSF between the concave pedicle and the cord. Type 3 is a spinal cord that is flattened/deformed by the apical concave pedicle or vertebral body, with no intervening CSF (Fig. 1). RESULTS: 128 patients were reviewed: 81 (63%) Type 1; 32 (25%) Type 2; and 12 (11.7%) Type 3 spinal cords. Lower extremity trans-cranial motor-evoked Potentials (MEPs) and/or somatosensory evoked potentials (SSEPs) were lost intraoperatively in 21 (16%) cases, with full recovery of data in 20 of those cases. On regression analysis, a Type 1 cord was protective against intraoperative data loss (OR = 0.17, p = 0.0003). Type 2 cords had no association with data loss (OR = 0.66, p = 0.49). Type 3 cords had significantly higher odds of intraoperative data loss (OR = 28.3, p < 0.0001). CONCLUSIONS: We present a new spinal cord risk classification scheme to identify patients with increased odds of losing spinal cord monitoring data with thoracic deformity correction. The odds of losing intraoperative MEPs/SSEPs are greater in type 3 spinal cords. LEVEL OF EVIDENCE: III.

Preoperative halo-gravity traction for treatment of severe adult kyphosis and scoliosis.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To assess the efficacy of preoperative halo-gravity traction (HGT) in the treatment for severe adult kyphosis and scoliosis. Preoperative HGT improves severe curve magnitude and clinical condition in pediatric spinal deformity. However, the efficacy of HGT on severe adult spinal deformity has rarely been studied. MATERIALS AND METHODS: This study included 18 patients with severe adult kyphosis and scoliosis (age ≥ 18) who underwent a preoperative HGT (mean 4 weeks), and subsequent definitive posterior-alone corrective fusion. Etiologies were neurofibromatosis (n = 5), adult idiopathic (n = 3), multiple vertebral fractures due to osteoporosis (n = 1) and multiple myeloma (n = 1), degenerative failed back syndrome (n = 1), Scheuermann kyphosis (n = 1), Marfan syndrome (n = 1), and other genetic and connective tissue disorders (n = 5). We reviewed baseline demographics, including coronal and sagittal radiographic profiles. The changes in major curve magnitude, pulmonary function tests (PFTs), and nutritional status were assessed between pre- and post-traction and immediate post-definitive corrective surgery. RESULTS: There were 11 male and 7 female patients, aged 18-69 years with their major coronal and sagittal curves being 92.0° ± 25.2° and 111.6° ± 40.1°, respectively. The major coronal and sagittal curves were reduced by 18.4% and 16.8% after halo-traction, and 54.7% and 44.2% after definitive fusion, respectively. PFTs showed significant increase in %FEV1 and %FVC when comparing pre- and post-traction [43.0% ± 17.4% vs. 49.6% ± 18.7%, and 44.8%. ± 16.7% vs. 54.3% ± 20.7%, respectively, p < 0.01 (n = 11)]. Effective weight gain was observed after traction (46.8 ± 14.5 vs. 49.3 ± 13.5 kg, p < 0.01). CONCLUSION: Halo-gravity traction (HGT) for severe coronal and sagittal plane spinal deformity in adult patients significantly reduced Cobb angles, improved PFTs, and allowed for effective weight gain in the preoperative period. The use of preoperative HGT is extremely beneficial to optimize the alignment and overall health of severe adult spinal deformity patients before their spinal reconstruction. LEVEL OF EVIDENCE: Level IV.

Reciprocal change of sagittal profile in unfused spinal segments and lower extremities after complex adult spinal deformity surgery including spinopelvic fixation: a full-body X-ray analysis.

BACKGROUND CONTEXT: Few studies have described reciprocal changes of pathologic compensatory mechanisms in the setting of spinopelvic fixation using full-body radiograph. PURPOSE: To elucidate how sagittal alignment of unfused spinal segments and lower extremities change reciprocally following complex thoracolumbar realignment surgery including fusion to the sacrum in adult spinal deformity. STUDY DESIGN: Retrospective cohort. PATIENT SAMPLE: Thirty-four patients who underwent fusion from lower thoracic to the sacrum/pelvis and 49 patients with fusion from upper thoracic to the sacrum/pelvis. OUTCOME MEASURES: The postoperative sagittal alignment change, and the correlation between the instrumented spinopelvic alignment change and reciprocal changes in unfused spinal segments/lower extremities. MATERIALS/METHODS: This study included 34 patients who underwent fusion from lower thoracic to the sacrum/pelvis (LT-P group) and 49 patients with fusion from upper thoracic to the sacrum/pelvis (UT-P group). The postoperative sagittal alignment changes were evaluated after subdividing the two groups according to T1 pelvic angle (TPA) (aligned group: TPA<20 and malaligned group: TPA>20). The correlation between the instrumented spinopelvic alignment change (ΔTPA and ΔLL), reciprocal changes in unfused spinal segments and lower extremities, and the cranial sagittal vertical axis-hip/ankle change (ΔCrSVA-Hip/Ankle) were also analyzed. RESULTS: At the baseline in both LT-P and UT-P groups, the patients in the malaligned subgroups showed greater C2-7 lordosis (C2-7L), sacrofemoral angle (SFA), and knee flexion angle (KA) than those in the aligned subgroups. At average 7.1 months postoperatively, these compensatory mechanisms were restored in accordance with instrumented TPA/LL change, especially in the UT-P group. The mid-thoracic alignment changed significantly kyphotic in the LT-P group. ΔTPA and ΔLL linearly correlated with ΔC2-7L, ΔKA, and ΔAA in the malaligned patients. The multivariate regression analysis revealed that change in lower extremity parameters (ΔSFA, ΔKA, and ΔAA) independently impacted ΔCrSVA-Hip/Ankle. CONCLUSION: Adequate thoracolumbar realignment surgery results in restoration of the pathologic compensatory mechanisms in the unfused spinal segments and lower extremities, especially in patients fused from upper thoracic spine. A preoperative clinical evaluation of the lower limb joints, as well as a full-body radiographic evaluation, is paramount to achieve optimal global sagittal balance in thoracolumbar realignment surgery.

The "kickstand rod" technique for correction of coronal imbalance in patients with adult spinal deformity: initial case series.

OBJECTIVE: The objective of this study was to describe and evaluate a new surgical procedure for the correction of coronal imbalance (CI) in adult spinal deformity patients, called the "kickstand rod" technique. METHODS: The authors analyzed the records of 24 consecutive patients with pediatric and adult spinal deformity and CI treated between July 2015 and October 2017 with a long-segment fusion and a kickstand rod. For the kickstand rod technique, an iliac screw was placed on the ipsilateral side of the trunk shift and connected proximally through a side-by-side domino link to the thoracolumbar junction; this rod was distracted to promote coronal plane balancing. Distraction occurred with the rod on the contralateral side locked in order to preserve sagittal correction. Radiographic and clinical analyses were conducted to evaluate the outcomes and possible complications of the kickstand rod technique. RESULTS: The mean age of the patients was 55 years (range 14-73 years). Eighteen of the 24 patients were female. CI preoperatively was a mean of 63 mm, and the mean measurement at the final follow-up (mean duration 1.4 years) was 47 mm. There were no neurological, vascular, or implant-related complications in any of the patients. One patient developed wound dehiscence that was successfully treated without implant removal, and one developed proximal junctional kyphosis requiring extension of the construct proximally. One patient also returned to the operating room for excision of a spinous process. There were no complaints about screw prominence, kickstand construct failure, or significant worsening of CI after surgery. CONCLUSIONS: The kickstand rod technique is safe and effective for the correction of CI in spinal deformity patients. This technique was found to provide marked coronal correction and additional strength to the overall construct without significant adverse consequences.

Intersurgeon Cost Variability in Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective review of prospective patient outcomes and cost data. OBJECTIVE: To analyze the contribution of surgeon-specific variability in cost and patient-reported outcomes (PROs) to overall variability in anterior cervical discectomy and fusion (ACDF), whereas adjusting for patient comorbidities. SUMMARY OF BACKGROUND DATA: Cost reduction in surgical care has received increased attention. Patient factors contributing to cost variability in ACDF have been described; however, intersurgeon cost and outcome variability has received less attention in the literature. METHODS: Adult patients undergoing elective primary ACDF by five different surgeons were analyzed from a prospective registry database. Direct and indirect 90-day costs were compared across each surgeon, along with PROs. Predicted costs were calculated based on patient co-morbidities, and an "observed versus expected" cost differential was measured for each surgeon; this O/E cost ratio was then compared with PROs. RESULTS: A total of 431 patients were included in the analysis. There were no differences in comorbidities, age, smoking status, or narcotic use. There was significant variation between surgeons in total 90-day costs, as well as variation between each surgeon's observed versus expected cost ratio. Despite these surgeon-specific cost variations, there were no differences in PROs across the participating surgeons. CONCLUSION: Intersurgeon cost variation in elective ACDF persists even after adjusting for patient comorbidities. There was no apparent correlation between increased surgeon-specific costs and 90-day PROs. These findings show there is opportunity for improvement in inter-surgeon cost variation without compromise in PROs. LEVEL OF EVIDENCE: 3.

Autologous chondrocyte grafting promotes bone formation in the posterolateral spine.

BACKGROUND CONTEXT: Pseudarthrosis following spinal fusion remains problematic despite modern surgical and grafting techniques. In surgical spinal fusion, new bone forms via intramembranous and endochondral ossification, with endochondral ossification occurring in the hypoxic zones of the fusion bed. During bone development and fracture healing, the key cellular mediator of endochondral ossification is the hypertrophic chondrocyte given its ability to function in hypoxia and induce neovascularization and ossification. We therefore hypothesize that hypertrophic chondrocytes may be an effective bone graft alternative. PURPOSE: Spinal fusion procedures have increased substantially; yet 5% to 35% of all spinal fusions may result in pseudoarthrosis. Pseudoarthrosis may occur because of implant failure, infection, or biological failure, among other reasons. Advances in surgical techniques and bone grafting have improved fusion; however pseudarthrosis rates remain unacceptably high. Thus, the goal of this study is to investigate hypertrophic chondrocytes as a potential biological graft alternative. METHODS: Using a validated murine fracture model, hypertrophic chondrocytes were harvested from fracture calluses and transplanted into the posterolateral spines of identical mice. New bone formation was assessed by X-ray, microcomputed tomography (µCT), and in vivo fluorescent imaging. Results were compared against a standard iliac crest bone graft and a sham surgery control group. Funding for this work was provided by the Department of Orthopaedics and Rehabilitation, the OREF (Grant #16-150), and The Caitlin Lovejoy Fund. RESULTS: Radiography, µCT, and in vivo fluorescent imaging demonstrated that hypertrophic chondrocytes promoted bone formation at rates equivalent to iliac crest autograft. Additionally, µCT analysis demonstrated similar fusion rates in a subset of mice from the iliac crest and hypertrophic chondrocyte groups. CONCLUSIONS: This proof-of-concept study indicates that hypertrophic chondrocytes can promote bone formation comparable to iliac crest bone graft. These findings provide the foundation for future studies to investigate the potential therapeutic use of hypertrophic chondrocytes in spinal fusion.

Impact of old age on patient-report outcomes and cost utility for anterior cervical discectomy and fusion surgery for degenerative spine disease.

PURPOSE: With growing older population and increasing rates of cervical spinal surgery, it is vital to understand the value of cervical surgery in this population. We set forth to determine the cost utility following anterior cervical decompression and fusion (ACDF) for degenerative disease in older patients. METHODS: Patients undergoing ACDF for degenerative diseases were enrolled into prospective longitudinal registry. Patient-reported outcomes (PROs) were recorded at baseline, 1-year, and 2-year postoperatively. Two-year medical resource utilization, missed work, and health-state values [quality-adjusted life years (QALYs)] were assessed to compute cost per QALY gained. Patients were dichotomized based on age: <65 years (younger) and ≥65 years (older) to compare the cost utility in these age groups. RESULTS: Total 218 (87%) younger patients and 33 (13%) older patients who underwent ACDF were analyzed. Both the groups demonstrated a significant improvement in PROs 2-year following surgery. The older patients had a lower mean cumulative gain in QALYs compared to younger patients at 1 year (0.141 vs. 0.28, P = 0.05) and 2 years (0.211 vs. 0.424, P = 0.04). There was no significant difference in the mean total 2-year cost between older [$21,041 (95% CI $18,466-$23,616)] and younger [$22,669 (95% CI $$21,259-$24,079)] patients (P = 0.27). Two-year cost per QALY gained in older vs. younger patients was ($99,720/QALYs gained vs. ($53,464/QALYs gained, P = 0.68). CONCLUSION: ACDF surgery provided a significant gain in health-state utility in older patients with degenerative cervical pathology, with a mean cumulative 2-year cost per QALY gained of $99,720/QALY. While older patients have a slightly higher cost utility compared to their younger counterparts, surgery in the older cohort does provide a significant improvement in pain, disability, and quality-of-life outcomes.

Effect of obesity on cost per quality-adjusted life years gained following anterior cervical discectomy and fusion in elective degenerative pathology.

BACKGROUND: Obese patients have greater comorbidities along with higher risk of complications and greater costs after spine surgery, which may result in increased cost and lower quality of life compared with their non-obese counterparts. PURPOSE: The aim of the present study was to determine cost-utility following anterior cervical discectomy and fusion (ACDF) in obese patients. STUDY DESIGN: This study analyzed prospectively collected data. PATIENT SAMPLE: Patients undergoing elective ACDF for degenerative cervical pathology at a single academic institution were included in the study. OUTCOME MEASURES: Cost and quality-adjusted life years (QALYs) were the outcome measures. METHODS: One- and two-year medical resource utilization, missed work, and health state values (QALYs) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national payment amounts (direct cost). Patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Total cost (direct+indirect) was used to compute cost per QALY gained. Patients were defined as obese for body mass index (BMI) ≥35 based on the WHO definition of class II obesity. A subgroup analysis was conducted in morbidly obese patients (BMI≥40). RESULTS: There were significant improvements in pain (neck pain or arm pain), disability (Neck Disability Index), and quality of life (EuroQol-5D and Short Form-12) at 2 years after surgery (p<.001). There was no significant difference in post-discharge health-care resource utilization, direct cost, indirect cost, and total cost between obese and non-obese patients at postoperative 1-year and 2-year follow-up. Mean 2-year direct cost for obese patients was $19,225±$8,065 and $17,635±$6,413 for non-obese patients (p=.14). There was no significant difference in the mean total 2-year cost between obese ($23,144±$9,216) and non-obese ($22,183±$10,564) patients (p=.48). Obese patients had a lower mean cumulative gain in QALYs versus non-obese patients at 2-years (0.34 vs. 0.42, p=.32). Two-year cost-utility in obese ($68,070/QALY) versus non-obese patients ($52,816/QALY) was not significantly different (p=.11). Morbidly obese patients had lower QALYs gained (0.17) and higher cost per QALYs gained ($138,094/QALY) at 2 years. CONCLUSIONS: Anterior cervical discectomy and fusion provided a significant gain in health state utility in obese patients, with a mean 2-year cost-utility of $68,070 per QALYs gained, which can be considered moderately cost-effective. Morbidly obese patients had lower cost-effectiveness; however, surgery does provide a significant improvement in outcomes. Obesity, and specifically morbid obesity, should to be taken into consideration as physician and hospital reimbursements move toward a bundled model.

Is obesity associated with worse patient-reported outcomes following lumbar surgery for degenerative conditions?

PURPOSE: To investigate whether obesity is associated with worse patient-reported outcomes following surgery for degenerative lumbar conditions. METHODS: We evaluated consecutive patients undergoing elective lumbar laminectomy or laminectomy with fusion for degenerative lumbar conditions. The Oswestry Disability Index (ODI), EuroQol-5D (EQ-5D), Short-Form 12 (SF-12), and NASS patient satisfaction were utilized. Chi-square tests and student t test assessed the association of obesity with PROs. Multivariate regression controlled for age, sex, smoking status, anxiety, depression, revision, preoperative narcotic use, payer status, and diabetes. RESULTS: A total of 602 patients were included. All PROs improved significantly in both groups. BMI ≥35 was associated with increased ODI at baseline (50.6 vs. 47.2 %, p = 0.012) and 12 months (30.5 vs. 25.7 %, p = 0.005). There was no difference in ODI change scores (21.2 vs. 19.4 %, p = 0.32). With multivariate analysis, BMI ≥35 was not predictive of worse ODI at 12 months (correlation coefficient 1.23, 95 % CI -0.225 to 2.676.) There was no significant difference between groups in percentage of patients achieving the minimum clinically important difference for ODI (59.6 vs. 64 %, p = 0.46) or patient satisfaction (80.5 vs. 78.9 %, p = 0.63). CONCLUSIONS: Body mass index ≥35 is associated with worse baseline and 12-month PROs, however, there was no difference in change scores across BMI groups. Controlling for important co-variables, BMI greater than 35 was not an independent predictor of worse PROs at 12 months.

Effect of complications within 90 days on patient-reported outcomes 3 months and 12 months following elective surgery for lumbar degenerative disease.

OBJECT There is a paradigm shift toward rewarding providers for quality rather than volume. Complications appear to occur at a fairly consistent frequency in large aggregate data sets. Understanding how complications affect long-term patient-reported outcomes (PROs) following degenerative lumbar surgery is vital. The authors hypothesized that 90-day complications would adversely affect long-term PROs. METHODS Nine hundred six consecutive patients undergoing elective surgery for degenerative lumbar disease over a period of 4 years were enrolled into a prospective longitudinal registry. The following PROs were recorded at baseline and 12-month follow-up: Oswestry Disability Index (ODI) score, numeric rating scales for back and leg pain, quality of life (EQ-5D scores), general physical and mental health (SF-12 Physical Component Summary [PCS] and Mental Component Summary [MCS] scores) and responses to the North American Spine Society (NASS) satisfaction questionnaire. Previously published minimum clinically important difference (MCID) threshold were used to define meaningful improvement. Complications were divided into major (surgicalsite infection, hardware failure, new neurological deficit, pulmonary embolism, hematoma and myocardial infarction) and minor (urinary tract infection, pneumonia, and deep venous thrombosis). RESULTS Complications developed within 90 days of surgery in 13% (118) of the patients (major in 12% [108] and minor in 8% [68]). The mean improvement in ODI scores, EQ-5D scores, SF-12 PCS scores, and satisfaction at 3 months after surgery was significantly less in the patients with complications than in those who did not have major complications (ODI: 13.5 ± 21.2 vs 21.7 ± 19, < 0.0001; EQ-5D: 0.17 ± 0.25 vs 0.23 ± 0.23, p = 0.04; SF-12 PCS: 8.6 ± 13.3 vs 13.0 ± 11.9, 0.001; and satisfaction: 76% vs 90%, p = 0.002). At 12 months after surgery, the patients with major complications had higher ODI scores than those without complications (29.1 ± 17.7 vs 25.3 ± 18.3, p = 0.02). However, there was no difference in the change scores in ODI and absolute scores across all other PROs between the 2 groups. In multivariable linear regression analysis, after controlling for an array of preoperative variables, the occurrence of a major complication was not associated with worsening ODI scores 12 months after surgery. There was no difference in the percentage of patients achieving the MCID for disability (66% vs 64%), back pain (55% vs 56%), leg pain (62% vs 59%), or quality of life (19% vs 14%) or in patient satisfaction rates (82% vs 80%) between those without and with major complications. CONCLUSIONS Major complications within 90 days following lumbar spine surgery have significant impact on the short-term PROs. Patients with complications, however, do eventually achieve clinically meaningful outcomes and report satisfaction equivalent to those without major complications. This information allows a physician to counsel patients on the fact that a complication creates frustration, cost, and inconvenience; however, it does not appear to adversely affect clinically meaningful long-term outcomes and satisfaction.

Do Patient Demographics and Patient-Reported Outcomes Predict 12-Month Loss to Follow-Up After Spine Surgery?

STUDY DESIGN: Analysis of patients in a prospective registry. OBJECTIVE: To determine the association between patient demographics, outcomes, and loss to follow-up 12 months after spine surgery. SUMMARY OF BACKGROUND DATA: Obtaining outcomes 12 months after spine surgery remains a challenge. Loss to follow-up is believed to introduce biases and portend poor outcomes. Associations between follow-up, patient demographics, and outcomes in the degenerative spine population have not been studied. METHODS: Patients undergoing surgery for degenerative spine disease at a single institution over a 2-year period were enrolled in a prospective registry. Patient demographics, comorbidities, treatment variables, readmissions/reoperations, and all 90-day surgical morbidity were collected. Patient-reported outcomes were recorded at baseline, 3-months, and 12-months after surgery. Multivariate logistic regression analysis was done to identify predictors of loss to follow-up. RESULTS: A total of 1484 patients with baseline and 3-month outcomes were included. Two hundred thirty-three (15.7%) patients were lost to follow-up at 12 months. There was no difference in the baseline demographics (Sex: P = 0.46) and comorbidities (American Society of Anesthesiologists Grade: P = 0.06) of patients who had follow-up at 12-months versus those who did not, except age and employment status. Patients lost to follow-up at 12 months were younger (51.0 vs. 57.1 years; P < 0.001) and a higher proportion were employed preoperatively (45.9% vs. 41.7%, P = 0.24). Preoperative pain, disability, and quality of life was similar between the two groups (P > 0.05). There was no difference in 90-day morbidity (17.2% vs. 16.2%; P = 0.70) and 3-month pain, disability, quality of life, and patient satisfaction (85.0% vs. 88.3%; P = 0.63) (P > 0.05). In multivariate model, only younger age (P < 0.001) was an independent predictor of loss to follow-up at 12 months. CONCLUSION: In our prospective spine registry the 12-month loss to follow-up rate is approximately 15%. The only independent predictor of loss to follow-up is younger age and preoperative employment. LEVEL OF EVIDENCE: 3.