Comparison of clinical outcomes in patients undergoing one- and two-level minimally invasive lumbar microdiscectomy.

OBJECTIVE: Herniated nucleus pulposus (HNP) is one of the most common lumbar spine conditions treated surgically, often through a minimally invasive surgery (MIS) microdiscectomy approach. This technique attempts to reduce damage to the paraspinal muscular-ligamentous envelope. However, there are currently limited data regarding comparative outcomes using patient-reported outcome measures (PROMs) for one- and two-level MIS discectomies. The aim of this study was to quantify comparative clinical outcomes in patients undergoing one-level and two-level MIS lumbar microdiscectomy for HNP using PROMs. METHODS: The authors performed a retrospective review of patients undergoing MIS lumbar microdiscectomy between 2004 and 2019 for the primary diagnosis of HNP at a single academic institution. All patients had a minimum 1-year follow-up. Patient demographics and comorbidities were collected to establish baselines between cohorts. PROMs and minimal clinically important differences (MCIDs) were used to examine the patient's perception of operative success. Bivariate and multivariate linear/logistic regression analyses were used to compare one- and two-level discectomies. The bivariate analysis included the t-test and chi-square test, which were used to assess continuous and categorical variables, respectively. Statistical significance was established at p < 0.05. RESULTS: A total of 293 patients underwent one-level (n = 250) or two-level (n = 43) MIS discectomies. The mean follow-ups for the one- and two-level cohorts were 50.4 (SD 35.5) months and 61.6 (SD 39.8) months, respectively. Fewer female patients underwent two-level discectomies, and BMI and operative duration were higher in the two-level group (p < 0.001). Recurrent herniation requiring reoperation was recorded at rates of 6.80% and 11.6% in the one- and two-level groups, respectively (p = 0.270). Pre- and postoperative PROMs were largely similar between the cohorts; however, patients undergoing one-level discectomy had greater improvement in leg pain, and a significantly greater proportion of these patients achieved MCID for the leg pain visual analog scale score (p < 0.001). CONCLUSIONS: At the 1-year clinical follow-up, patients who underwent two-level discectomy had significantly less improvement in leg pain scores with lower achievement of MCID for leg pain improvement than patients undergoing one-level procedures. At the 1-year follow-up, there were no other significant differences in PROMs between the two cohorts. Given these findings, patients should be counseled regarding the anticipated outcomes to better manage expectations. Further studies are warranted to examine the long-term clinical outcomes associated with single- and multilevel MIS discectomy.

Adult Spinal Deformity Correction in Patients with Parkinson Disease: Assessment of Surgical Complications, Reoperation, and Cost.

BACKGROUND: Parkinson disease (PD) is a neurodegenerative disorder that manifests with postural instability and gait imbalance. Correction of spinal deformity in patients with PD presents unique challenges. METHODS: The PearlDiver database was queried between 2010 and 2020 to identify adult patients with spinal deformity before undergoing deformity correction with posterior spinal fusion. Two cohorts were created representing patients with and without a preoperative diagnosis of PD. Outcome measures included reoperation rates, surgical technique, cost, surgical complications, and medical complications. Multivariable logistic regression adjusting for Charlson Comorbidity Index, age, gender, 3-column osteotomy, pelvic fixation, and number of levels fused was used to assess rates of reoperation and complications. RESULTS: In total, 26,984 patients met the inclusion criteria and were retained for analysis. Of these patients, 725 had a diagnosis of PD before deformity correction. Patients with PD underwent higher rates of pelvic fixation (odds ratio [OR], 1.33; P < 0.001) and 3-column osteotomies (OR, 1.53; P < 0.001). On adjusted regression, patients with PD showed increased rates of reoperation at 1 year (OR, 1.37; P < 0.001), 5 years (OR, 1.32; P < 0.001), and overall (OR, 1.33; P < 0.001). Patients with PD also experienced an increased rate of medical complications within 30 days after deformity correction including deep venous thrombosis (OR, 1.60; P = 0.021), pneumonia (OR, 1.44; P = 0.039), and urinary tract infections (OR, 1.54; P < 0.001). Deformity correction in patients with PD was associated with higher 90-day cost (P = 0.007). CONCLUSIONS: Patients with PD undergoing long fusion for deformity correction are at significantly increased risk of 30-day medical complications and revision procedures after 1 year, controlling for comorbidities, age, and invasiveness. Surgeons should consider the risk of complications, subsequent revision procedures, and increased cost.

Adjacent Segment Disease After Spinal Fusion.

¼ Adjacent segment disease is characterized by a degenerative process adjacent to a previously fused spine segment, with new onset of clinical symptoms such as radiculopathy, myelopathy, or instability.¼ Etiology is related to the natural history of the disease process, increased biomechanical stress at adjacent segments, clinical factors specific to the individual patient, intraoperative factors, and malalignment.¼ Treatment is usually nonoperative, but surgical intervention can be indicated. Decompression and fusion remain the mainstay of operative treatment, and isolated decompression should be considered in specific cases.¼ Further randomized controlled trials are needed to establish how the treatment should progress, particularly with the development of minimally invasive and endoscopic surgery.

Endplate abnormalities, Modic changes and their relationship to alignment parameters and surgical outcomes in the cervical spine.

Modic changes (MC) and endplate abnormalities (EA) have been shown to impact preoperative symptoms and outcomes following spinal surgery. However, little is known about how these phenotypes impact cervical alignment. This study aimed to evaluate the impact that these phenotypes have on preoperative, postoperative, and changes in cervical alignment in patients undergoing anterior cervical discectomy and fusion (ACDF). We performed a retrospective study of prospectively collected data of ACDF patients at a single institution. Preoperative magnetic resonance imagings (MRIs) were used to assess for the MC and EA. Patients were subdivided into four groups: MC-only, EA-only, the combined Modic-Endplate-Complex (MEC), and patients without either phenotype. Pre and postoperative MRIs were used to assess alignment parameters. Associations with imaging phenotypes and alignment parameters were assessed, and statistical significance was set at p < 0.5. A total of 512 patients were included, with 84 MC-only patients, 166 EA-only patients, and 71 patients with MEC. Preoperative MC (p = 0.031) and the MEC (p = 0.039) had significantly lower preoperative T1 slope compared to controls. Lower preoperative T1 slope was a risk factor for MC (p = 0.020) and MEC (p = 0.029) and presence of MC (Type II) and the MEC (Type III) was predictive of lower preoperative T1 slope. There were no differences in postoperative alignment measures or patient reported outcome measures. MC and endplate pathologies such as the MEC appear to be associated with worse cervical alignment at baseline relative to patients without these phenotypes. Poor alignment may be an adaptive response to these degenerative findings or may be a risk factor for their development.

Clinical Outcomes of Robotic Versus Freehand Pedicle Screw Placement After One-to Three-Level Lumbar Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The purpose of this study is to compare patient-reported outcome measures (PROMs) for patients undergoing one-to three-level lumbar fusion using robotically assisted vs freehand pedicle screw placement. METHODS: Patients who underwent either robotically assisted or freehand pedicle screw placement for one-to three-level lumbar fusion surgery from January 1, 2014 to August 31, 2020 at a single academic institution were identified. Propensity score matching was performed based on demographic variables. Clinical and surgical outcomes were compared between groups. Recovery Ratios (RR) and the proportion of patients achieving the minimally clinically important difference (%MCID) were calculated for Oswestry Disability Index, PCS-12, MCS-12, VAS Back, and VAS Leg at 1 year. Surgical outcomes included complication and revision rates. RESULTS: A total of 262 patients were included in the study (85 robotic and 177 freehand). No significant differences were found in ΔPROM scores, RR, or MCID between patients who underwent robotically assisted vs freehand screw placement. The rates of revision (1.70% freehand vs 1.18% robotic, P = 1.000) and complications (.57% freehand vs 1.18% robotic, P = .546) were not found to be statically different between the 2 groups. Controlling for demographic factors, procedure type (robotic vs freehand) did not emerge as a significant predictor of ΔPROM scores on multivariate linear regression analysis. CONCLUSIONS: Robotically assisted pedicle screw placement did not result in significantly improved clinical or surgical outcomes compared to conventional freehand screw placement for patients undergoing one-to three-level lumbar fusion.

Porous Polyetheretherketone Interbody Cages for Anterior Cervical Discectomy and Fusion at 3 or More Levels: Clinical and Radiographic Outcomes.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) at 3 or more levels remains challenging, with reported high pseudarthrosis rates and implant-related complications. Porous surface polyetheretherketone (PEEK) interbody cages are newer implants for ACDF with limited data available for their use in ACDF procedures at 3 or more levels. The objective of this study was to assess the clinical and radiographic outcomes of porous PEEK devices for ACDF at 3 or more levels. STUDY DESIGN: Retrospective case series. METHODS: Consecutive patients who underwent primary ACDF for degenerative cervical disc disease at 3 or more levels with porous PEEK cages with anterior plate instrumentation were included. Clinical outcome scores, radiographic parameters, pseudarthrosis rates, and cage subsidence rates were assessed. Preoperative and postoperative clinical outcomes and radiographic measures were compared using paired t tests. RESULTS: A total of 33 patients with ACDF at 3 or more levels with porous PEEK cages were included, with minimum 1-year follow-up. Two patients had cage subsidence (6.1%), and 1 patient had pseudarthrosis (3.0%). There were significant postoperative increases in overall cervical lordosis, sagittal vertical axis, fusion segment lordosis, T1 slope, and disc height. Clinical outcomes showed significant improvement from the preoperative visit to the final postoperative follow-up. CONCLUSIONS: High rates of fusion (97.0%) were observed in this challenging patient cohort, which compares favorably with previously published rates of fusion in ACDF at 3 or more levels. CLINICAL RELEVANCE: The optimal management of cervical spinal pathology regarding approach, technique, and implants used is an active area of ongoing investigation. The high levels of radiographic and clinical success utilizing a relatively novel implant material in a high-risk surgical cohort reported here may influence surgical decision making.

Perioperative Management of Spinal Cord Stimulators and Intrathecal Pain Pumps.

Spinal cord stimulators (SCSs) and intrathecal pain pumps (IPPs) are implantable devices used in the management of chronic pain or spasticity. Complications, such as infection, lead migration/failure, cerebrospinal fluid leak, neurologic injury, and other medical complications, can occur after placement and may require surgical intervention. Orthopaedic surgeons may encounter patients with these devices and should have a basic understanding of their function. In addition, they should be aware that patients may have residual stenosis or deformity contributing to their symptoms; thus, spine surgery referral may be indicated. If a patient with a SCS or IPP is undergoing revision spinal surgery, a preoperative discussion regarding retention versus removal of the device is imperative because indications for device retention, revision, and removal are complex. This review summarizes potential complications and intraoperative considerations concerning the proper perioperative management of SCSs/IPPs and will provide evidence-based data regarding management strategies for these devices.

Ossified Ligamentum Flavum: Epidemiology, Treatment, and Outcomes.

Ossification of the ligamentum flavum (OLF) is an uncommon but potentially serious spinal condition which can cause progressive compression of the spinal canal with associated devastating neurologic compromise. Although debate exists regarding the exact etiology of OLF, overexpression of genes and transcription factors centered around the Notch and Wnt signaling pathways because of increased mechanical stress seems to be related. There are many clinical and radiographic presentations of OLF; however, progressive myelopathy is the most commonly encountered. Radiographic analysis may reveal isolated OLF or OLF combined with ossification of other areas of the spine, such as disk, posterior longitudinal ligament, and dura. When surgery is necessary for OLF, several surgical strategies exist including open laminectomy with excision, endoscopic decompression, Bridge Crane resection, en block resection, and combined anterior and posterior approaches. Resection may be complicated by dural adhesion or dural ossification, and postoperative neurologic deficits are not uncommon.

Pediatric Back Pain: A Scoring System to Guide Use of Magnetic Resonance Imaging.

BACKGROUND: The prevalence of back pain in the pediatric population is increasing, and the workup of these patients presents a clinical challenge. Many cases are selflimited, but failure to diagnose a pathology that requires clinical intervention can carry severe repercussions. Magnetic resonance imaging (MRI) carries a high cost to the patient and health care system, and may even require procedural sedation in the pediatric population. The aim of this study was to develop a scoring system based on pediatric patient factors to help determine when an MRI will change clinical management. METHODS: This is a retrospective cohort analysis of consecutive pediatric patients who presented to clinic with a chief complaint of back pain between 2010 and 2018 at single orthopaedic surgery practice. Comprehensive demographic and presentation variables were collected. A predictive model of factors that influence whether MRI results in a change in management was then generated using cross-validation least absolute shrinkage and selection operator logistic regression analysis. RESULTS: A total of 729 patients were included, with a mean age of 15.1 years (range: 3 to 20 y). Of these, 344 (47.2%) had an MRI. A predictive model was generated, with nocturnal symptoms (5 points), neurological deficit (10 points), age (0.7 points per year), lumbar pain (2 points), sudden onset of pain (3.25 points), and leg pain (3.75 points) identified as significant predictors. A combined score of greater than 9.5 points for a given patient is highly suggestive that an MRI will result in a change in clinical management (specificity: 0.93; positive predictive value: 0.92). CONCLUSIONS: A predictive model was generated to help determine when ordering an MRI may result in a change in clinical management for workup of back pain in the pediatric population. The main factors included the presence of a neurological deficit, nocturnal symptoms, sudden onset, leg pain, lumbar pain, and age. Care providers can use these findings to better determine if and when an MRI might be appropriate. LEVEL OF EVIDENCE: Level III-diagnostic study.

The Modic-endplate-complex phenotype in cervical spine patients: Association with symptoms and outcomes.

This study describes a novel, combined Modic changes (MC) and structural endplate abnormality phenotype of the cervical spine, which we have termed the Modic-Endplate-Complex (MEC), and its association with preoperative symptoms and outcomes in anterior cervical discectomy and fusion (ACDF) patients. This was a retrospective study of prospectively collected data at a single institution. Preoperative cervical magnetic resonance imagings were used to assess the presence of MC and endplate abnormalities. Patients were divided into four groups: MC-only, endplate abnormality-only, the MEC and controls. The MEC was defined as the presence of both a MC and endplate abnormality in the cervical spine. Phenotypes were further stratified by location and compared to controls. Associations with patient-reported outcome measures were assessed using regression controlling for baseline characteristics. A total of 628 patients were included, with 84 MC-only, 166 endplate abnormality-only, and 187 MEC patients. Both MC (p < 0.001) and endplate abnormalities (p < 0.001) were independently associated with one another. MC at the adjacent level (p = 0.018), endplate abnormalities (regardless of location) (p = 0.001), and the MEC within the fusion segment (p = 0.027) were all associated with higher Neck Disability Index scores. Both MC within the fusion segment (p = 0.008) and endplate abnormalities within the fusion segment (p = 0.017) associated with lower Veteran's Rand 12-item scores. MC and structural endplate abnormalities commonly manifest concomitantly in patients indicated for ACDF for degenerative pathology. Patients with the endplate pathology, including the MEC phenotype, reported significantly higher levels of postoperative disability following ACDF. These findings add valuable data to the prognostic assessment of degenerative cervical spine patients.

High-Intensity Zones on MRI of the Cervical Spine in Patients: Epidemiology and Association With Pain and Disability.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to address the prevalence, distribution, and clinical significance of cervical high-intensity zones (HIZs) on magnetic resonance imaging (MRI) with respect to pain and other patient-reported outcomes in the setting of patients that will undergo an anterior cervical discectomy and fusion (ACDF) procedure. METHODS: A retrospective cohort study of ACDF patients surgically treated at a single center from 2008 to 2015. Based on preoperative MRI, HIZ subtypes were identified as either traditional T2-hyperintense, T1-hypointense ("single-HIZs"), or combined T1- and T2-hyperintense ("dual-HIZs"), and their level-specific prevalence was assessed. Preoperative symptoms, patient-reported outcomes, and disc degeneration pathology were assessed in relation to HIZs and HIZ subtypes. RESULTS: Of 861 patients, 58 demonstrated evidence of HIZs in the cervical spine (6.7%). Single-HIZs and dual-HIZs comprised 63.8% and 36.2% of the overall HIZs, respectively. HIZs found outside of the planned fusion segment reported better preoperative Neck Disability Index (NDI; P = .049) and Visual Analogue Scale (VAS) Arm (P = .014) scores relative to patients without HIZs. Furthermore, patients with single-HIZs found inside the planned fusion segment had worse VAS Neck (P = .045) and VAS Arm (P = .010) scores. In general, dual-HIZ patients showed no significant differences across all clinical outcomes. CONCLUSIONS: This is the first study to evaluate the clinical significance of HIZs in the cervical spine, noting level-specific and clinical outcome-specific variations. Single-HIZs were associated with significantly more pain when located inside the fusion segment, while dual-HIZs showed no associations with patient-reported outcomes. The presence of single-HIZs may correlate with concurrent spinal pathologies and should be more closely evaluated.

Symptomatic Postoperative Epidural Hematoma in the Lumbar Spine.

A symptomatic postoperative epidural hematoma (SPEH) in the lumbar spine is a complication with variable presentation and the potential to rapidly cause an irrecoverable neurological injury. Significant heterogeneity exists among current case series reporting SPEH in the literature. This review attempts to clarify the known incidence, risk factors, and management pearls. Currently, literature does not support the efficacy of subfascial drains in reducing the incidence of SPEHs and possibly suggests that medication for thromboembolism prophylaxis may increase risk. Acute back pain and progressing lower extremity motor weakness are the most common presenting symptoms of SPEH. Magnetic resonance imaging is the mainstay of diagnostic imaging necessary to confirm the diagnosis, but if not acutely available, an immediate return to the operative theater for exploration without advanced imaging is justified. Treatment of a SPEH consists of emergent hematoma evacuation as a delay in repeat surgery has a deleterious effect on neurological recovery. Outcomes are poorly defined, though a significant portion of patients will have lasting neurological impairments even when appropriately recognized and managed.

Patients Undergoing 3-Level-or-Greater Decompression-Only Surgery for Lumbar Spinal Stenosis Have Similar Outcomes to Those Undergoing Single-Level Surgery at 2 Years.

BACKGROUND: Stability following multilevel decompressive laminectomy without fusion has been debated using in vitro biomechanical and radiographic models. However, there is a lack of information regarding clinical outcomes for these patients. The aim of the present study was to determine the association between clinical outcomes and number of levels decompressed via laminectomy for treatment of lumbar spinal stenosis. METHODS: We performed a retrospective cohort analysis of patients who underwent a primary lumbar laminectomy between 2009 and 2015 by senior orthopedic spine surgeons for lumbar spinal stenosis. Patients were divided into 2 groups based on the number of decompression levels: single level or 3 or more levels. Patient-reported outcomes were obtained in the form of Oswestry Disability Index (ODI) scores, visual analog scale (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey scores, and Veterans Rand 12-Item Health Mental and Physical Survey scores. RESULTS: Overall, 138 consecutive patients were assessed, of which 106 underwent a single-level and 32 underwent a 3-or-more-level laminectomy. Average follow-up was 24.2 months. There were no significant differences in the preoperative VAS back, VAS leg, or ODI scores between the single-level laminectomy and 3-or-more-level laminectomy groups. Both groups of patients experienced significant improvements in these clinical outcomes postoperatively with no clinically significant difference in the degree of improvement. Reoperation rates were low and similar between the 2 groups. CONCLUSIONS: Patients undergoing decompression of 3 or more levels present with similar postoperative outcomes to those who undergo a single-level decompression for lumbar spinal stenosis. Under specific clinical and radiographic criteria, a multilevel decompression of 3 or more levels may be a safe and effective procedure with acceptable outcomes at 2 years after surgery. LEVEL OF EVIDENCE: 3.

Artificial intelligence predicts disk re-herniation following lumbar microdiscectomy: development of the "RAD" risk profile.

PURPOSE: Surgical treatment of herniated lumbar intervertebral disks is a common procedure worldwide. However, recurrent herniated nucleus pulposus (re-HNP) may develop, complicating outcomes and patient management. The purpose of this study was to utilize machine-learning (ML) analytics to predict lumbar re-HNP, whereby a personalized risk prediction can be developed as a clinical tool. METHODS: A retrospective, single center study was conducted of 2630 consecutive patients that underwent lumbar microdiscectomy (mean follow-up: 22-months). Various preoperative patient pain/disability/functional profiles, imaging parameters, and anthropomorphic/demographic metrics were noted. An Extreme Gradient Boost (XGBoost) classifier was implemented to develop a predictive model identifying patients at risk for re-HNP. The model was exported to a web application software for clinical utility. RESULTS: There were 1608 males and 1022 females, 114 of whom experienced re-HNP. Primary herniations were central (65.8%), paracentral (17.6%), and far lateral (17.1%). The XGBoost algorithm identified multiple re-HNP predictors and was incorporated into an open-access web application software, identifying patients at low or high risk for re-HNP. Preoperative VAS leg, disability, alignment parameters, elevated body mass index, symptom duration, and age were the strongest predictors. CONCLUSIONS: Our predictive modeling via an ML approach of our large-scale cohort is the first study, to our knowledge, that has identified significant risk factors for the development of re-HNP after initial lumbar decompression. We developed the re-herniation after decompression (RAD) profile index that has been translated into an online screening tool to identify low-high risk patients for re-HNP. Additional validation is needed for potential global implementation.

Reasons for revision following stand-alone anterior lumbar interbody fusion and lateral lumbar interbody fusion.

OBJECTIVE: Anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) are alternative and less invasive techniques to stabilize the spine and indirectly decompress the neural elements compared with open posterior approaches. While reoperation rates have been described for open posterior lumbar surgery, there are sparse data on reoperation rates following these less invasive procedures without direct posterior decompression. This study aimed to evaluate the overall rate, cause, and timing of reoperation procedures following anterior or lateral lumbar interbody fusions without direct posterior decompression. METHODS: This was a retrospective cohort study of all consecutive patients indicated for an ALIF or LLIF for lumbar spine at a single academic institution. Patients who underwent concomitant posterior fusion or direct decompression surgeries were excluded. Rates, causes, and timing of reoperations were analyzed. Patients who underwent a revision decompression were matched with patients who did not require a reoperation, and preoperative imaging characteristics were analyzed to assess for risk factors for the reoperation. RESULTS: The study cohort consisted of 529 patients with an average follow-up of 2.37 years; 40.3% (213/529) and 67.3% (356/529) of patients had a minimum of 2 years and 1 year of follow-up, respectively. The total revision rate was 5.7% (30/529), with same-level revision in 3.8% (20/529) and adjacent-level revision in 1.9% (10/529) of patients. Same-level revision patients had significantly shorter time to revision (7.14 months) than adjacent-level revision patients (31.91 months) (p < 0.0001). Fifty percent of same-level revisions were for a posterior decompression. After further analysis of decompression revisions, an increased preoperative canal area was significantly associated with a lower risk of further decompression revision compared to the control group (p = 0.015; OR 0.977, 95% CI 0.959-0.995). CONCLUSIONS: There was a low reoperation rate after anterior or lateral lumbar interbody fusions without direct posterior decompression. The majority of same-level reoperations were due to a need for further decompression. Smaller preoperative canal diameters were associated with the need for revision decompression.

Comparison Between Three- and Four-Level Anterior Cervical Discectomy and Fusion: Patient-Reported and Radiographic Outcomes.

OBJECTIVE: We compared the long-term clinical and radiographic outcomes after 3- and 4-level anterior cervical discectomy and fusion (ACDF) in a retrospective cohort study. METHODS: Patients who had undergone primary 3- or 4-level ACDF were retrospectively identified. The demographic data and patient-reported outcome measures (PROMs) were collected through a review of the medical records. PROM surveys were administered preoperatively for baseline measurements and at 1 year postoperatively. The surveys included the Neck Disability Index, 12-item short-form physical component summary, 12-item short-form mental component summary, and visual analog scale (VAS) scores for neck and arm pain. The cervical sagittal alignment parameters included C2-C7 lordosis, segmental lordosis, the sagittal vertical axis (SVA), and the T1 slope. Multivariate regression models were used to compare the changes in the PROMs and radiographic measurements over time between 3- and 4-level ACDF. Correlation coefficients were calculated to compare the delta scores for the PROMs and radiographic measurements. RESULTS: The VAS scores for neck and arm pain had significantly improved from baseline in both cohorts. Only the 3-level group showed significant improvements perioperatively in the Neck Disability Index and 12-item short-form physical component summary. No significant differences were found in the improvement in clinical outcomes between the 2 groups. The pooled results demonstrated a significant negative correlation between the perioperative changes in segmental lordosis and VAS scores for arm pain. A significant negative correlation was also found between the perioperative changes in the SVA and 12-item short-form mental component summary and VAS scores for neck pain. C2-C7 lordosis significantly increased postoperatively only in the 3-level ACDF group. CONCLUSIONS: Patients undergoing both 3- and 4-level ACDF experienced significant clinical improvement without significant differences between the 2 groups. The radiographic measures of segmental lordosis and SVA also correlated with the changes in clinical outcomes.

Duration of Symptoms Does Not Affect Clinical Outcome After Lumbar Arthrodesis.

STUDY DESIGN: Retrospective cohort study at a single institution. OBJECTIVE: To examine the effect of symptom duration on clinical outcomes after posterolateral lumbar fusion. SUMMARY OF BACKGROUND DATA: Nonoperative measures are generally exhausted before patients are indicated for surgical intervention, leaving patients with their symptomatology for varying lengths of time. It is unclear at what point in time surgical intervention may become less efficacious at alleviating preoperative symptoms. MATERIALS AND METHODS: Consecutive patients who underwent primary elective open posterior lumbar spinal fusion at a single academic institution were included. Patient and operative characteristics were compared between symptom duration groups (group 1: <12 mo of pain, group 2: ≥12 mo of pain). Preoperative and final postoperative visual analog scale back/leg pain, and Oswestry Disability Index, were collected. Preoperative, immediate postoperative, and final radiographs were assessed to measure lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), and the PI-LL difference was calculated. RESULTS: In total, 167 patients were included in group 1, whereas 359 patients were included in group 2. Baseline demographics and operative characteristics were similar between the 2 groups. Both groups had similar changes in sagittal parameters and had no significant difference in rates of complication, reoperation, discharge to rehabilitation facility, or early adjacent segment degeneration. Both groups demonstrated similar improvement in clinical outcome measures. CONCLUSIONS: Despite differences in symptom duration, patients who had pain for ≥12 months demonstrated similar improvement after posterolateral lumbar arthrodesis than those who had pain for <12 months. Extended effort of conservative treatments or delay of operative intervention does not appear to negatively impact the eventual outcome of surgery. LEVEL OF EVIDENCE: Level III.

Does the Number of Levels Fused Affect Spinopelvic Parameters and Clinical Outcomes Following Posterolateral Lumbar Fusion for Low-Grade Spondylolisthesis?

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To determine how the number of fused intervertebral levels affects radiographic parameters and clinical outcomes in patients undergoing open posterolateral lumbar fusion (PLF) for low-grade degenerative spondylolisthesis. METHODS: This was a retrospective cohort study on patients who underwent open PLF for low-grade spondylolisthesis at a single institution from 2011 to 2018. Patients were divided into groups based on number of levels fused during their procedure (1, 2, or 3 or more). Preoperative and postoperative spinopelvic radiographic parameters, patient-reported outcomes (Visual Analog Scale [VAS]-back, VAS-leg, Oswestry Disability Index [ODI]), and postoperative complications were compared. RESULTS: Of the 316 patients eligible (203 one-level, 95 two-level, 18 three or more levels), change in initial postoperative to final pelvic incidence-lumbar lordosis was greatest in 2-level fusions (P = .039), while 3 or more level fusions had worse final pelvic tilt measures (P = .021). In addition, multilevel fusions had worse final VAS-back scores (2-level: P = .015; 3 or more levels: P = .011), higher rates of dural tears (2-level: P = .001), reoperation (2-level: P = .039), and discharge to facility (3 or more levels: P = .047) when compared with 1-level fusions. CONCLUSIONS: Patients in multilevel fusions experienced less improvement in back pain, had more complications, and were more commonly discharged to a facility compared with single-level PLF patients. These findings are important for operative planning, for setting appropriate preoperative expectations, and for risk stratification in patients undergoing posterior lumbar fusion for low-grade spondylolisthesis.

Cervical spine MRI phenotypes and prediction of pain, disability and adjacent segment degeneration/disease after ACDF.

Degenerative spine imaging findings have been extensively studied in the lumbar region and are associated with pain and adverse clinical outcomes after surgery. However, few studies have investigated the significance of these imaging "phenotypes" in the cervical spine. Patients with degenerative cervical spine pathology undergoing anterior cervical discectomy and fusion (ACDF) from 2008 to 2015 were retrospectively and prospectively assessed using preoperative MRI for disc degeneration, narrowing, and displacement, high-intensity zones, endplate abnormalities, Modic changes, and osteophyte formation from C2-T1. Points were assigned for these phenotypes to generate a novel Cervical Phenotype Index (CPI). Demographics were evaluated for association with phenotypes and the CPI using forward stepwise regression. Bootstrap sampling and multiple imputations assessed phenotypes and the CPI in association with patient-reported outcomes (Neck Disability Index [NDI], Visual Analog Scale [VAS]-neck, VAS-arm) and adjacent segment degeneration (ASDeg) and disease (ASDz). Of 861 patients, disc displacement was the most common (99.7%), followed by osteophytes (92.0%) and endplate abnormalities (57.3%). Most findings were associated with age and were identified at similar cervical vertebral levels; at C5-C7. Imaging phenotypes demonstrated both increased and decreased associations with adverse patient-reported outcomes and ASDeg/Dz. However, the CPI consistently predicted worse NDI (P = .012), VAS-neck (P = .007), and VAS-arm (P = .013) scores, in addition to higher odds of ASDeg (P = .002) and ASDz (P = .004). The CPI was significantly predictive of postoperative symptoms of pain/disability and ASDeg/Dz after ACDF, suggesting that the totality of degenerative findings may be more clinically relevant than individual phenotypes and that this tool may help prognosticate outcomes after surgery.