Biomechanical Comparison of Corticopedicular Spine Fixation versus Pedicle Screw Fixation in a Lumbar Degenerative Spondylolisthesis Finite Element Analysis Model.

OBJECTIVE: To compare the stability of a corticopedicular posterior fixation (CPPF) device to traditional pedicle screws for decompression and fusion in adult degenerative lumbar spondylolisthesis. METHODS: Finite element analysis (FEA) was used in a validated model of grade 1 L4-L5 spondylolisthesis to compare segmental stability following laminectomy alone, laminectomy with pedicle screw fixation, or laminectomy with CPPF device fixation. A 500N follower load was applied to the model and different functional movements were simulated by applying a 7.5Nm force in different directions. Outcomes included degrees of motion, tensile forces experienced in the CPPF device, and stresses in surrounding cortical bone. RESULTS: At maximum loading, laminectomy alone demonstrated an 1° increase in flexion range of motion from 6.35° to 7.39°. Laminectomy with pedicle screw fixation and CPPF device fixation both reduced spinal segmental motion to ≤1° at maximum loading in all ranges of motion, including flexion (0.94° and 1.09°), extension (-0.85°and -1.08°), lateral bending (-0.56° and -0.96°), and torsion (0.63°and 0.91°), respectively. There was no significant difference in segmental stability between pedicle screw fixation and CPPF device fixation during maximum loading with a difference of ≤0.4° in any range of motion. Tensile forces in the CPPF device remained ≤51% the ultimate load to failure (487N) and stress in surrounding cortical bone remained ≤84% the ultimate stress of cortical bone (125.4 MPa) during maximum loading. CONCLUSION: CPFF fixation demonstrated similar segmental stability to traditional pedicle screw fixation while tensile forces and stress in surrounding cortical bone remained below the load to failure.

Are tourniquets indicated in total knee arthroplasty in the era of tranexamic acid: A meta-analysis and systematic review.

Introduction: There is conflicting evidence in the literature regarding the clinical utility of tourniquets in total knee arthroplasty (TKA), specifically in regards to perioperative blood loss. In this meta-analysis and systematic review, we aim to evaluate the clinical advantages and disadvantages associated with tourniquet use in the setting of TKA. Methods: A systematic review was conducted through April 2017 using keywords: "tourniquet" and "total knee arthroplasty" or "total knee replacement". Perioperative variables including TXA use, blood loss, incidence of venous thromboembolism (VTE), and wound complications were either extracted from the studies or corresponding authors were contacted. A sub-analysis was conducted to evaluate the effects of TXA on intraoperative and total blood loss (TBL), and VTE incidence. Results: After review of 558 articles, 19 studies reporting outcomes in 1094 patients were analyzed. Intraoperative blood loss was significantly lower in the tourniquet cohorts compared to non-tourniquet (p < 0.01). TBL was reduced in tourniquet groups but not significantly (p = 0.08). In contrast, calculated blood loss was greater in tourniquet groups, but this difference was not significant (p = 0.43). There was a greater likelihood for wound complications and VTE among tourniquet assisted TKA, albeit only significant for the former (p = 0.01). TXA sub-analysis demonstrated intraoperative blood loss was significantly reduced with tourniquet use regardless of TXA implementation (p < 0.01). In studies without TXA, tourniquet patients were at greater risk of developing VTE (p = 0.08). These risks decreased with TXA administration. Conclusion: This meta-analysis demonstrates that tourniquets prevent intraoperative blood loss, yet within the postoperative period, there is no significant difference in TBL between tourniquet and non-tourniquet assisted TKA. Level of evidence: Level II; Systematic Review and Meta-Analysis.

Which North American spine society disc herniation morphology descriptors are most associated with improvements in clinical outcomes after microdiscectomy?

Background: The North American Spine Society (NASS) assembled the first ever comprehensive naming system for describing lumbar disc disease, including lumbar disc herniation. The objectives of this study were (1) to determine which NASS descriptors are most predictive of independent patient-reported outcomes after microdiscectomy and (2) to identify the inter-rater reliability of each NASS descriptor. Methods: Adult patients (≥18 years) who underwent a lumbar microdiscectomy from 2014-2021 were retrospectively identified. Patient-reported outcome measures (PROMs) were collected at preoperative, 3-month, and 1-year postoperative time points. Lumbar disc herniations were evaluated and classified on preoperative MRI using the NASS lumbar disc nomenclature specific to disc herniation. Results: About 213 microdiscectomy patients were included in the final analysis. Herniation descriptors exhibiting the greatest reliability included sequestration status (κ=0.83), axial disc herniation area (κ=0.83), and laterality (κ=0.83). The descriptor with the lowest inter-rater reliability was direction of migration (κ=0.53). At 3 months, a sequestered herniation was associated with lower odds of achieving the minimal clinically important difference (MCID) for ODI (p=.004) and MCS (p=.032). At 12 months, a similar trend was observed for Oswestry Disability Index (ODI) MCID achievement (p=.001). At 3 months, a herniation with larger axial area was a predictor of MCID achievement in ODI (p=.004) and the mental component summary (MCS) (p=.009). Neither association persisted at 12 months; however, larger axial disc herniation area was able to predict MCID achievement in the Visual Analogue Scale (VAS) leg (p=.031) at 12 months. Conclusions: The utility of the NASS nomenclature system in predicting postoperative outcomes after microdiscectomy has yet to be studied. We showed that sequestration status and disc area are both reliable and able to predict the odds of achieving MCID in certain clinical outcomes at 3 months and 12 months after surgery. Hence, preoperative imaging analysis of lumbar disc herniations may be useful in accurately setting patient expectations.

Immediate Versus Delayed Venous Thromboembolism Prophylaxis Following Spine Surgery: Increased Rate of Unplanned Reoperation for Postoperative Hematoma with Immediate Prophylaxis.

BACKGROUND CONTEXT: There is significant variability in postoperative chemoprophylaxis protocols amongst spine providers due to perceived risks and benefits, but limited data on the topic. At our institution, both orthopaedic spine and neurosurgery departments utilize unfractionated subcutaneous heparin in identical dosages and frequency, with the only difference being time to initiation postoperatively. PURPOSE: To evaluate the rate of symptomatic venous thromboembolism (VTEs) and unplanned reoperation for hematoma based on timing of chemoprophylaxis initiation. STUDY DESIGN/SETTING: Single institution retrospective cohort study PATIENT SAMPLE: Patients undergoing elective spine surgery, excluding patients undergoing surgery in the setting of trauma, malignancy, or infection OUTCOME MEASURES: Outcome measures included the diagnosis of a venous thromboembolism within 90 days of surgery and unplanned reoperation for a hematoma METHODS: Patients undergoing elective spine surgery from 2017 to 2021 were grouped based on chemoprophylaxis protocol. In the "immediate" group, patients received subcutaneous heparin 5000 units every 8 hours starting immediately after surgery, and in the "delayed" group, patients received chemoprophylaxis starting postoperative day (POD)-2 for any decompressions and/or fusions involving a spinal cord level (i.e., L2 and above) and POD-1 for those involving only levels below the spinal cord (i.e., L3 to pelvis). A cox proportional hazards model was created to assess independent predictors of venous thromboembolic events, while a logistic regression was utilized for unplanned reoperations for hematoma. RESULTS: Of 8,704 patients, a total of 98 (1.13%) VTE events occurred, of which 43 (0.49%) were pulmonary embolism. Fifty-four patients (0.62%) had unplanned reoperations for postoperative hematomas. On cox proportional hazards model analysis, immediate chemoprophylaxis was not protective of a venous thromboembolism (Hazard Ratio: 1.18, p=0.436), but, it was a significant independent predictor for unplanned reoperation for hematoma on multivariable logistic regression modeling (Odds Ratio: 3.29, p<0.001). CONCLUSIONS: Both chemoprophylaxis protocols in our study resulted in low rates of VTE and postoperative hematoma. However, our findings suggest that the delayed chemoprophylaxis protocol may mitigate postoperative hematoma formation without increasing the risk for a thrombotic event.

Physical and Psychological Impact of Scar Cosmesis after Cervical Spine Fusion Surgery.

INTRODUCTION: Patients' and surgeons' perceptions of cutaneous scarring can vary, causing unpleasant physical and psychological outcomes. This study aims to bridge the current scientific literature gap and understand the impact of patient-perceived scar cosmesis after anterior and posterior cervical spine surgery. METHODS: Retrospective review of patients ≥18 years old who underwent anterior or posterior cervical spine surgery from 2017 to 2022 at a large, urban academic group. To select patients with adequate time for surgical scar maturation, only patients who were greater than six months post-surgery were included. The SCAR-Q survey, a surgical scar assessment tool, was administered to patients to assess patient perceptions of scar symptomatology, appearance, and psychosocial impact. Scores range from 0 to 100, with 100 as the best outcome. An additional 5-item Likert scale question was administered to assess overall surgical satisfaction. RESULTS: All 854 respondents who completed the survey were stratified into two groups"Unsatisfied vs Satisfied." Patients who were "unsatisfied" with their surgery had the lowest outcome scores for SCAR-Q appearance, symptom, and psychosocial scores than those who were "satisfied" (p<0.001). Females had significantly higher/"more favorable" responses for SCAR-Q Appearance (77.5 vs. 82.8 p<0.001) and Psychosocial (87.4 vs. 94.3 p<0.001) scores compared to males. Regression analysis performed for each component score showed that increases in all three component scores were significant in patients in the satisfied group. CONCLUSIONS: Our study demonstrates that cervical spine surgery patients unsatisfied with their surgical outcome have lower scar-related scores, highlighting the impact of cosmetic closure and appearance.

Preoperative Radiographic Predictors of Subsequent Fusion after Lumbar Decompression Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study is to determine which demographic, surgical, and radiographic preoperative characteristics are most associated with the need for subsequent fusion after decompression lumbar spinal surgery. SUMMARY OF BACKGROUND DATA: There is a relatively high rate of the need for repeat decompression or fusion after an index decompression procedure for degenerative spine disease. Nevertheless, there is a dearth of literature identifying risk factors for lumbar fusion following decompression surgery. METHODS: Patients 18 years or older receiving a primary lumbar decompression surgery within the levels of L3-S1 between 2011 and 2020 were identified. All patients had preoperative radiographs and 2 years of follow-up data. Chart review was performed for surgical characteristics and demographics. The sagittal parameters included lumbar lordosis (LL), segmental lordosis (SL), anterior disc height (aDH), posterior disk height (pDH), sacral slope (SS), and pelvic tilt (PT). Pelvic incidence (PI=PT+SS) and pelvic incidence minus lumbar lordosis (PI-LL) were calculated. In addition, the Roussouly classification was determined for each patient. Bivariant and multivariant analyses were performed. RESULTS: Of the 363 patients identified in this study, 96 patients had a fusion after their index decompression surgery. Multivariable analysis identified involvement of L4-L5 level in the decompression (odds ratio (OR)=1.83 (1.09-3.14), P=0.026), increased L5-S1 segmental lordosis (OR=1.08 (1.03-1.13), P=0.001), decreased SS (OR=0.96 (0.93-0.99), P=0.023), and decreased endplate obliquity (OR=0.88 (0.77-0.99), P=0.040) as significant independent predictors of fusion after decompression surgery. CONCLUSIONS: This is one of the first studies to assess preoperative sagittal parameters in conjunction with demographic variables to determine predictors of the need for fusion after index decompression. We demonstrated that decompression at L4-L5, greater L5-S1 segmental lordosis, decreased sacral slope, and decreased endplate obliquity were associated with higher rates of fusion after decompression surgery.

Impact of Preoperative Intervertebral Disc Degeneration on Patient-Reported Outcome Measures After Lumbar Fusion.

OBJECTIVE: The Pfirrmann scoring system classifies lumbosacral disc degeneration based on MRI signal intensity. The relationship between pre-existing disc degeneration and PROMs after one-level lumbar fusion is not well documented. The purpose of this study was to investigate the relationship between the severity of preoperative intervertebral disc degeneration and pre- and postoperative patient-reported outcome measures (PROMs) in patients undergoing one-level lumbar fusion. METHODS: All adult patients underwent posterior lumbar decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF) between 2014-2022 were included. Patient demographics, and comorbidities were extracted from medical records. Lumbar intervertebral discs on sagittal MRI T2-weighted images were assessed by two independent graders utilizing Pfirrmann criteria. Grades I-III were categorized as low-grade disc degeneration, while IV-V were considered high-grade. Multivariable linear regression assessed the impact of disc degeneration on PROMS. RESULTS: A total of 150 patients were included, of which, 69 (46%) had low grade disc degeneration, while 81 (54%) had high grade degeneration. Patients with high-grade degeneration had increased preoperative VAS-Leg scores (6.10 vs. 4.54, p=0.005) and displayed greater one-year postoperative improvements in VAS-Back scores (-2.11 vs -0.66, p=0.002). Multivariable regression demonstrated Pfirrmann scores as independent predictors for both preoperative VAS-Leg scores (p=0.004) and postoperative VAS-Back improvement (p=0.005). CONCLUSIONS: In patients undergoing one-level lumbar fusion, higher Pfirmann scores were associated with increased preoperative leg pain and greater one-year postoperative improvement in back pain. Further studies into the relationship of pre-operative disc degeneration and their impact on postoperative outcomes may help guide clinical decision making and patient expectations.

The Impact of Outpatient Physical Therapy on Patient-Reported Outcomes After Lumbar Fusion: Perspective from A Bundled Care Dataset.

OBJECTIVE/BACKGROUND: As value-based care grows in popularity across the United States, more payers have turned toward bundled payment models for surgical procedures. Though episode costs in spine are highly variable, physical therapy (PT) has been identified as a driver of 90-day cost. The goal of this study is to assess the impact of postoperative PT on patient-reported outcomes and cost after lumbar fusion surgery using bundled insurance data. METHODS: Bundled payment information of lumbar fusion episodes-of-care (EOC) from 2019 to 2021 was reviewed at a single, urban, tertiary care center. EOC comprised a 210-day period surrounding the date of the procedure, beginning 30 days preoperatively and ending 180 days postoperatively. Patients were grouped into physical therapy (PT) and no physical therapy (no PT) groups based on the presence of PT claims. RESULTS: Bivariate analysis of surgical outcomes revealed similar overall complication rates (P = 0.413), 30-day readmissions (P = 0.366), and 90-day readmissions (P = 0.774). Patients who did not participate in postoperative PT had significantly better preoperative physical component score (PCS) (P = 0.003), 6-month postoperative PCS (P = 0.001), and 6-month ΔPCS (P = 0.026) compared with patients who participated in postoperative PT. At 1-year follow-up, patients who did not participate in PT had less leg pain (P = 0.041) than those who did participate in PT. CONCLUSIONS: Our study finds that PT after lumbar fusion is not associated with significant improvement in Oswestry Disability Index, PCS, mental component score, or visual analog scale pain scores. Additionally, the number of PT sessions a patient attends has no correlation with improvement in these outcomes.

Postoperative opioid consumption patterns diverge between propensity matched patients undergoing traumatic and elective cervical spine fusion.

BACKGROUND CONTEXT: Prolonged opioid therapy following spine surgery is an ongoing postoperative concern. While prior studies have investigated postoperative opioid use patterns in the elective cervical surgery patient population, to our knowledge, opioid use patterns in patients undergoing surgery for traumatic cervical spine injuries have not been elucidated. PURPOSE: The purpose of this study was to compare opioid use and prescription patterns in the postoperative pain management of patients undergoing traumatic and elective cervical spine fusion surgery. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Adult patients with traumatic cervical injuries who underwent primary anterior cervical discectomy and fusion (ACDF) or posterior cervical decompression and fusion (PCDF) during their initial hospital admission. The propensity matched, control group consisted of adult elective cervical fusion patients who underwent primary ACDF or PCDF. OUTCOME MEASURES: Demographic data, surgical characteristics, spinal disease diagnosis, location of cervical injury, procedure type, operative levels fused, and Prescription Drug Monitoring Program (PDMP) data. PDMP data included the number of opioid prescriptions filled, preoperative opioid use, postoperative opioid use, and use of perioperative benzodiazepines, muscle relaxants, or gabapentin. Opioid consumption data was collected in morphine milligram equivalents (MME) and standardized per day. METHODS: A 1:1 propensity match was performed to match traumatic injury patients undergoing cervical fusion surgery with elective cervical fusion patients. Traumatic injury patients were matched based on age, sex, CCI, procedure type, and cervical levels fused. Pre- and postoperative opioid, benzodiazepine, muscle relaxant, and gabapentin use were assessed for the traumatic injury and elective patients. T- or Mann-Whitney U tests were used to compare continuous data and Chi-Squared or Fisher's Exact were used to compare categorical data. Multivariate stepwise regression using MME per day 0 - 30 days following surgery as the dependent outcome was performed to further evaluate associations with postoperative opioid use. RESULTS: A total of 48 patients underwent fusion surgery for a traumatic cervical spine injury and 48 elective cervical fusion with complete PDMP data were assessed. Elective patients were found to fill more prescriptions (3.19 vs. 0.65, p=.023) and take more morphine milligram equivalents (MME) per day (0.60 vs. 0.04, p=.014) within 1 year prior to surgery in comparison to traumatic patients. Elective patients were also more likely to use opioids (29.2% vs. 10.4%, p=.040) and take more MMEs per day (0.70 vs. 0.05, p=.004) within 30 days prior to surgery. Within 30 days postoperatively, elective patients used opioids more frequently (89.6% vs. 52.1%, p<.001) and took more MMEs per day (3.73 vs. 1.71, p<.001) than traumatic injury patients. Multivariate stepwise regression demonstrated preoperative opioid use (Estimate: 1.87, p=.013) to be correlated with higher postoperative MME per day within 30 days of surgery. Surgery after traumatic injury was correlated with lower postoperative MME use per day within 30 days of surgery (Estimate: -1.63 p=.022). CONCLUSION: Cervical fusion patients with a history of traumatic spine injury consume fewer opioids in the early postoperative period in comparison to elective cervical fusion patients, however both cohorts consumed a similar amount after the initial 30-day postoperative period. Preoperative opioid use was also a risk factor for higher consumption in the short-term postoperative period. These results may aid physicians in further understanding patients' postoperative care needs based on presenting injury characteristics and highlights the need for enhanced follow-up care for traumatic cervical spine injury patients after fusion surgery.

The Impact of the Preoperative Mental Health Component Summary (MCS) Score on Short-term Outcomes after Lumbar Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study is to characterize the relationship between preoperative MCS and surgical outcomes after lumbar spine surgery including inpatient complications, length of stay, readmissions, and reoperations. SUMMARY OF BACKGROUND DATA: As the prevalence of mental health disorders in the United States increases, it is important to identify risks associated with poor mental health status in the surgical spine patient. The mental health component summary (MCS) of the Short Form-12 has been used extensively as an indication of a patient's mental health status and psychological well-being. METHODS: Adult patients older than or equal to 18 years who underwent primary one to three level lumbar fusion surgery at our academic medical institution from 2017 to 2021 were retrospectively identified. Preoperative MCS score was used to analyze outcomes in patients based on a cutoff (<45.6). A score >45.6 indicated better preoperative mental health and a score <45.6 indicated worse preoperative mental health. RESULTS: Patients with lower preoperative MCS scores had longer hospital stays (3.86 + 2.16 vs. 3.55 + 1.42 days, P=0.010) and were more likely to have inpatient renal complications (3.09% vs. 7.19%, P=0.006). Patients with lower preoperative MCS scores also had lower Activity Measure for Post-Acute Care (AM-PAC) scores (17.1 + 2.85 vs. 17.6 + 2.49, P=0.030). Ninety-day surgical readmissions, medical readmissions, and reoperations were not significantly different between groups (P>0.05). CONCLUSION: Our study suggests that patients with lower preoperative mental health scores (MCS < 45.6) were independently more likely to experience more renal complications and longer length of stay after primary lumbar fusion. Additionally, higher MCS scores may correlate with better postoperative mobility and daily activity scores. Nevertheless, long-term outcomes are not significantly different between patients of better or worse preoperative mental health.

Comparison of Length of Stay and Discharge Disposition after Short-Segment Lumbar Fusion Surgery at Tertiary Care and Non-Tertiary Care Hospitals: A Propensity Score Matched Analysis.

STUDY DESIGN: A retrospective study. OBJECTIVE: To compare the perioperative and postoperative outcomes among lumbar fusion patients treated at an orthopaedic specialty hospital (OSH), a hybrid community hospital (HCH), and a conventional community hospital in comparison to a tertiary care hospital (TCH). SUMMARY OF BACKGROUND DATA: In spine surgery, strategies to reduce length of stay (LOS) include a myriad of pre-, intra-, and postoperative strategies that require a multidisciplinary infrastructure. The sum of these efforts has led to the creation of orthopedic specialty hospitals and protocols that have been adopted by community hospitals as well. There is a notable lack of information regarding the results of these efforts across different healthcare institution models. METHODS: This was a retrospective study of patients undergoing elective one or two-level lumbar fusion between 2017 and 2022 at a large urban TCH, an OSH, a HCH, and a conventional CH. Data was collected on patient characteristics, demographics, comorbidities, BMI, smoking status, surgical type, surgical levels, surgery duration, hospital length of stay, readmissions, reoperations, and discharge status within a year. Patients across the four surgical settings were matched based on age, BMI, CCI, type of procedure, and number of levels fused. RESULTS: A total of 1435 patients met the inclusion criteria. Length of hospital stay was significantly longer at TCH compared to OSH, HCH, and CH by an average of 1-2 days (P<0.001). 90-day readmissions were higher at TCH compared to OSH (P=0.001). TCH patients also were less likely to be discharged home than OSH and HCH patients (P=0.001 and P=0.016, respectively). No significant differences were noted in 1-year reoperation rates across all hospital models. CONCLUSION: Shorter lengths of stays and more home discharges at the orthopaedic specialty hospital and community hospital settings did not compromise surgical quality or postoperative outcomes.

The attainment of a patient acceptable symptom state in patients undergoing revision spine fusion.

INTRODUCTION: Revision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision. METHODS: We retrospectively identified all 1-3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22. RESULTS: We identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47). CONCLUSIONS: The majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations.

A Comparison of Clinical Outcomes Between Anterior Cervical Discectomy and Fusion Versus Posterior Cervical Laminoplasty for Multilevel Cervical Myelopathy.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: To compare patient-reported outcomes and surgical outcomes after anterior cervical discectomy and fusion (ACDF) versus cervical laminoplasty for multilevel cervical spondylotic myelopathy. BACKGROUND: Treatment options for multilevel cervical spondylotic myelopathy include ACDF and cervical laminoplasty. Given that the literature has been mixed regarding the optimal approach, especially in patients without kyphosis, there is a need for additional studies investigating outcomes between ACDF and cervical laminoplasty. METHODS: A retrospective review was conducted of adult patients undergoing 3 or 4-level surgery. Patients with preoperative kyphosis based on C2-C7 Cobb angles were excluded. The electronic medical record and institutional databases were reviewed for baseline characteristics, surgical outcomes, and patient-reported outcomes. RESULTS: A total of 101 patients who underwent ACDF and 52 patients who underwent laminoplasty were included in the study. The laminoplasty cohort had a higher overall Charlson Comorbidity Index (3.10 ± 1.43 vs 2.39 ± 1.57, P = 0.011). Both groups had a comparable number of levels decompressed, C2-C7 lordosis, and diagnosis of myelopathy versus myeloradiculopathy. Patients who underwent laminoplasty had a longer length of stay (2.04 ± 1.15 vs 1.48 ± 0.70, P = 0.003) but readmission, complication, and revision rates were similar. Both groups had similar improvement in myelopathy scores (∆modified Japanese Orthopedic Association: 1.11 ± 3.09 vs 1.06 ± 3.37, P = 0.639). ACDF had greater improvement in Neck Disability Index (∆Neck Disability Index: -11.66 ± 19.2 vs -1.13 ± 11.2, P < 0.001), neck pain (∆Visual Analog Scale-neck: -2.69 ± 2.78 vs -0.83 ± 2.55, P = 0.003), and arm pain (∆Visual Analog Scale-arm: -2.47 ± 3.15 vs -0.48 ± 3.19, P = 0.010). These findings persisted in multivariate analysis except for Neck Disability Index. CONCLUSION: ACDF and cervical laminoplasty appear equally efficacious at halting myelopathic progression. However, patients who underwent ACDF had greater improvements in arm pain at 1 year postoperatively. Longitudinal studies evaluating the efficacy of laminoplasty to mitigate adjacent segment disease are indicated to establish a robust risk-benefit assessment for these 2 procedures. LEVEL OF EVIDENCE: III.

Preoperative Electrodiagnostic Study Findings Differ Between Patients With Double-crush Syndrome and Carpal Tunnel Syndrome: A Propensity Matched Analysis.

INTRODUCTION: Double-crush syndrome (DCS) represents a condition that involves peripheral nerve compression in combination with spinal nerve root impingement. The purpose of this study was to compare electrodiagnostic study (EDS) results in patients undergoing carpal tunnel release (CTR) for carpal tunnel syndrome with those undergoing both CTR and anterior cervical diskectomy and fusion for DCS. METHODS: Patients receiving an isolated CTR were compared with those undergoing CTR and anterior cervical diskectomy and fusion within two years of CTR. The latter group was defined as our DCS cohort. Electrodiagnostic study results were collected which included sensory and motor nerve conduction data as well as electromyogram (EMG) findings. All electrodiagnostic studies were done before CTR in both sets of patients. RESULTS: Fifty-four patients with DCS and 137 CTR-only patients were included. Patients with DCS were found to have decreased sensory onset latency (3.51 vs 4.01; P = 0.015) and peak latency (4.25 vs 5.17; P = 0.004) compared with the CTR-only patients. Patients with DCS had slower wrist motor velocity (30.5 vs 47.7; P = 0.012), decreased elbow motor latency (9.62 vs 10.6; P = 0.015), and faster elbow motor velocity (56.0 vs 49.4; P = 0.031). EMG results showed that patients with DCS were more likely to have positive findings in the biceps (31.9% vs 1.96%; P < 0.001) and triceps (24.4% vs 2.97%; P < 0.001), but not abductor pollicis brevis (APB) (45.7% vs 37.9%; P = 0.459). CONCLUSION: We identified changes on EDS between patients with and without DCS. In patients with DCS, sensory nerve studies showed shorter peak and onset latency than in CTR-only patients. Interestingly, DCS and CTR-only patients had different patterns of wrist and elbow motor nerve conduction. Providers observing positive EMG findings proximal to the APB should raise their suspicion for possible cervical radiculopathy and when present with carpal tunnel syndrome-like symptoms, should also consider DCS in their diagnostic differential.

Does Paraspinal Muscle Mass Predict Lumbar Lordosis before and after Decompression for Degenerative Spinal Stenosis?

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: The purpose of this study was to determine if muscle mass and quality of the lumbar paraspinal muscles was associated with improvements in lumbar lordosis and other sagittal parameters after isolated posterior lumbar decompression surgery for lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Over time, either due to degenerative changes or other spinal conditions, individuals may develop sagittal imbalance. In patients with lumbar spinal stenosis, sagittal imbalance can further exacerbate symptoms of pain and radiculopathy. Sarcopenia of paraspinal muscles has been implicated in previous spine research as a variable with influence on surgical outcomes. METHODS: Sagittal parameters were measured on preoperative and postoperative lateral lumbar radiographs and included lumbar lordosis (LL), sacral slope (SS), and pelvic tilt (PT). Preoperative MRI images were evaluated at the base of the L4 vertebral body to assess muscles mass of the psoas muscle and paravertebral muscles (PVM) and Goutallier grade of the PVM. Patients were divided into 3 muscle size groups based on PVM normalized for body size (PVM/BMI): Group A (smallest), Group B, and Group C (largest). RESULTS: Patients in Group C had greater LL preoperatively (51.5° vs. 47.9° vs. 43.2, P=0.005) and postoperatively (52.2° vs. 48.9° vs. 45.7°, P=0.043). There was no significant difference in the ∆LL values between groups (P>0.05). Patients in Group C had larger SS preoperatively (35.2° vs. 32.1° vs. 30.0°, P=0.010) and postoperatively (36.1° vs. 33.0° vs. 31.7°, P=0.030). Regression analysis showed that PVM/BMI was a significant predictor of LL preoperatively (P=0.039) and postoperatively (P=0.031), as well as SS preoperatively (P=0.001) and postoperatively (P<0.001). CONCLUSION: Muscle mass of the paravertebral muscles significantly impacts lumbar lordosis and sacral slope in patients with lumbar spinal stenosis before and after posterior lumbar decompression. These findings highlight a need to address risk factors for poor muscle quality in patients with sagittal imbalance.

The Role of L1PA in Patient Reported Outcomes in Patients Undergoing Single Level Lumbar Fusion for Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine whether the L1 pelvic angle (L1PA) can be used to predict quality of life outcomes for adults one year after L4-L5 fusion to treat degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: L1PA is beneficial in the evaluation of pre and postoperative quality of life outcomes in patients undergoing surgery for spinal deformity. No studies have examined its utility in surgical patients with degenerative spinal disease. METHODS: Patients undergoing L4-L5 posterolateral decompression and fusion or transforaminal lumbar interbody fusion for degenerative lumbar spondylolisthesis were grouped by preoperative and postoperative L1PA, and further stratified by cut offs of>7.2° and <7.2° based on previous literature. We also stratified patients by presence of an ideal calculated L1PA, defined as (0.5xPelvic Incidence)-21 +/- 5°, as proposed by prior literature. Preoperative, one year postoperative and Δ (postoperative minus preoperative) patient reported outcome measures (PROMs) and radiographic measurements were collected. RESULTS: Twenty-four patients were identified with preoperative L1PAs <7.2° and 132 with L1PAs>7.2°. Eighteen patients were identified with postoperative L1PAs <7.2° and 138 with L1PAs>7.2°. Sixty-five and fifty-seven patients were identified as having ideal calculated pre and postoperative L1PAs, respectively. When using absolute cutoffs, L1PA correlated with pelvic tilt, pelvic incidence, and pelvic incidence-lumbar lordosis mismatch (PI-LL). When using calculated L1PAs, L1PA correlated with lumbar lordosis, PI-LL, pelvic tilt and sacral slope. With respect to PROMs, no statistically significant differences existed between cohorts both preoperatively and at 1 year postoperatively on either univariate and multivariate analyses. CONCLUSION: L1PA may be a helpful radiographic consideration that translates to clinically relevant outcomes in spinal deformity. However, it does not appear as predictive of patient outcomes after single level fusion for patients with L4-L5 degenerative spondylolisthesis. Further studies are warranted to investigate the role of L1PA in degenerative spine patients.

The impact of robotic assistance for lumbar fusion surgery on 90-day surgical outcomes and 1-year revisions.

Objectives: To evaluate the (1) 90-day surgical outcomes and (2) 1-year revision rate of robotic versus nonrobotic lumbar fusion surgery. Methods: Patients >18 years of age who underwent primary lumbar fusion surgery at our institution were identified and propensity-matched in a 1:1 fashion based on robotic assistance during surgery. Patient demographics, surgical characteristics, and surgical outcomes, including 90-day surgical complications and 1-year revisions, were collected. Multivariable regression analysis was performed. Significance was set to P < 0.05. Results: Four hundred and fifteen patients were identified as having robotic lumbar fusion and were matched to a control group. Bivariant analysis revealed no significant difference in total 90-day surgical complications (P = 0.193) or 1-year revisions (P = 0.178). The operative duration was longer in robotic surgery (287 + 123 vs. 205 + 88.3, P ≤ 0.001). Multivariable analysis revealed that robotic fusion was not a significant predictor of 90-day surgical complications (odds ratio [OR] = 0.76 [0.32-1.67], P = 0.499) or 1-year revisions (OR = 0.58 [0.28-1.18], P = 0.142). Other variables identified as the positive predictors of 1-year revisions included levels fused (OR = 1.26 [1.08-1.48], P = 0.004) and current smokers (OR = 3.51 [1.46-8.15], P = 0.004). Conclusion: Our study suggests that robotic-assisted and nonrobotic-assisted lumbar fusions are associated with a similar risk of 90-day surgical complications and 1-year revision rates; however, robotic surgery does increase time under anesthesia.

Relating preoperative MCS-12 to microdiscectomy outcomes.

PURPOSE: To determine the impact of poor mental health on patient-reported and surgical outcomes after microdiscectomy. METHODS: Patients ≥ 18 years who underwent a single-level lumbar microdiscectomy from 2014 to 2021 at a single academic institution were retrospectively identified. Patient-reported outcomes (PROMs) were collected at preoperative, three-month, and one-year postoperative time points. PROMs included the Oswestry Disability Index (ODI), Visual Analog Scale Back and Leg (VAS Back and VAS Leg, respectively), and the mental and physical component of the short form-12 survey (MCS and PCS). The minimum clinically important differences (MCID) were employed to compare scores for each PROM. Patients were categorized as having worse mental health or better mental health based on a MCS threshold of 50. RESULTS: Of 210 patients identified, 128 (61%) patients had a preoperative MCS score ≤ 50. There was no difference in 90-day surgical readmissions or spine reoperations within one year. At 3- and 12-month time points, both groups demonstrated improvements in all PROMs (p < 0.05). At three months postoperatively, patients with worse mental health had significantly lower PCS (42.1 vs. 46.4, p = 0.004) and higher ODI (20.5 vs. 13.3, p = 0.006) scores. Lower mental health scores were associated with lower 12-month PCS scores (43.3 vs. 48.8, p < 0.001), but greater improvements in 12-month ODI (- 28.36 vs. - 18.55, p = 0.040). CONCLUSION: While worse preoperative mental health was associated with lower baseline and postoperative PROMs, patients in both groups experienced similar improvements in PROMs. Rates of surgical readmissions and reoperations were similar among patients with varying preoperative mental health status.

The Relationship Between Disc Herniation Morphology and Patient-Reported Outcomes after Microdiscectomy.

OBJECTIVE: Determine if herniation morphology based on the Michigan State University Classification is associated with differences in (1) patient-reported outcome measures (or (2) surgical outcomes after a microdiscectomy. METHODS: Adult patients undergoing single-level microdiscectomy between 2014 and 2021 were identified. Demographics and surgical characteristics were collected through a query search and manual chart review. The Michigan State University classification, which assesses disc herniation laterality (zone A was central, zone B/C was lateral) and degree of extrusion into the central canal (grade 1 was up to 50% of the distance to the intra-facet line, grade >1 was beyond this line), was identified on preoperative MRIs. patient-reported outcome measures were collected at preoperative, 3-month, and 1-year postoperative time points. RESULTS: Of 233 patients, 84 had zone A versus 149 zone B/C herniations while 76 had grade 1 disc extrusion and 157 had >1 grade. There was no difference in surgical outcomes between groups (P > 0.05). Patients with extrusion grade >1 were found to have lower Physical Component Score at baseline. On bivariate and multivariable logistic regression analysis, extrusion grade >1 was a significant independent predictor of greater improvement in Physical Component Score at three months (estimate = 7.957; CI: 4.443-11.471, P < 0.001), but not at 1 year. CONCLUSIONS: Although all patients were found to improve after microdiscectomy, patients with disc herniations extending further posteriorly reported lower preoperative physical function but experienced significantly greater improvement three months after surgery. However, improvement in Visual Analog Scale Leg and back, ODI, and MCS at three and twelve months was unrelated to laterality or depth of disc herniation.

Preoperative Hounsfield Units Predict Pedicle Screw Loosening in Osteoporotic Patients Following Short Segment Lumbar Fusion.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: (1) To determine if vertebral HU values obtained from preoperative CT predict postoperative outcomes following 1-3 level lumbar fusion and (2) to investigate whether decreased BMD values determined by HU predict cage subsidence and screw loosening. SUMMARY OF BACKGROUND DATA: In light of suboptimal screening for osteoporosis, vertebral computerized tomography(CT) Hounsfield Units(HU), have been investigated as a surrogate for bone mineral density(BMD). METHODS: In this retrospective study, adult patients who underwent 1-3 level posterior lumbar decompression and fusion(PLDF) or transforaminal lumbar interbody and fusion(TLIF) for degenerative disease between the years 2017-2022 were eligible for inclusion. Demographics and surgical characteristics were collected. Outcomes assessed included 90-day readmissions, 90-day complications, revisions, patient reported outcomes(PROMs), cage subsidence, and screw loosening. Osteoporosis was defined as HU of ≤110 on preoperative CT at L1. RESULTS: We assessed 119 patients with a mean age of 59.1, of whom 80.7% were white and 64.7% were nonsmokers. The majority underwent PLDF(63%) compared to TLIF(37%), with an average of 1.63 levels fused. Osteoporosis was diagnosed in 37.8% of the cohort with a mean HU in the osteoporotic group of 88.4 compared to 169 in non-osteoporotic patients. Although older in age, osteoporotic individuals did not exhibit increased 90-day readmissions, complications, or revisions compared to non-osteoporotic patients. A significant increase in the incidence of screw loosening was noted in the osteoporotic group with no differences observed in subsidence rates. On multivariable linear regression osteoporosis was independently associated with less improvement in visual analog scale(VAS) scores for back pain. CONCLUSIONS: Osteoporosis predicts screw loosening and increased back pain. Clinicians should be advised of the importance of preoperative BMD optimization as part of their surgical planning and the utility of vertebral CT HU as a tool for risk stratification. LEVEL OF EVIDENCE: 3.