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 severity of preoperative anemia escalates risk of poor short-term outcomes after lumbar spine fusion.

OBJECTIVE: To evaluate how preoperative anemia severity affects 90-day outcomes of spinal fusion surgery. METHODS: A retrospective cohort study was conducted on adult lumbar fusion patients at a tertiary medical center. Patients were classified by World Health Organization anemia severity definitions for comparisons. Multivariate regression models were created to control for confounding variables, for all primary outcomes of transfusion requirements, non-home discharge, readmissions, complications, and length of stay. RESULTS: A total of 2582 patients were included: 2.7% with moderate-severe anemia, 11.0% with mild anemia, and 86.3% without anemia. Moderate-severe patients had the longest hospital stay (5.03 days vs 4.14 and 3.59 days, p < 0.001) and highest risk of transfusion (52.2% vs 13.0% vs 2.69%, p < 0.001), non-home discharge (39.1% vs 27.8% vs 15.4%, p < 0.001), readmission (7.25% vs 5.99% vs 3.36%, p = 0.023), and complications (13.0% vs 9.51% vs 6.20%, p = 0.012). On multivariable logistic regression, both patients with mild and moderate-severe anemia had an increased risk of transfusion (OR: 37.3, p < 0.001; OR: 5.25, p < 0.001, respectively) and non-home discharge (OR: 2.00, p = 0.021; OR: 1.71, p = 0.001, respectively) compared to patients without anemia. Anemia severity was not independently associated with complications or 90-day readmission. On multivariable linear regression, mild anemia (ß: 0.37, p = 0.001) and moderate-severe anemia (ß: 1.07, p < 0.001) were independently associated with length of hospital stay. CONCLUSION: Patients with moderate-severe preoperative anemia are at increased risk for longer length of stay, transfusions, and non-home discharge. Improved optimization of preoperative anemia may significantly reduce healthcare utilization, and surgeons should consider these risks in preoperative planning. LEVEL OF EVIDENCE: III.

The impact of cage positioning on lumbar lordosis and disc space restoration following minimally invasive lateral lumbar interbody fusion.

OBJECTIVE: The objective of this study was to evaluate patient and surgical factors that predict increased overall lumbar lordosis (LL) and segmental lordosis correction following a minimally invasive lateral lumbar interbody fusion (LLIF) procedure. METHODS: A retrospective review was conducted of all patients who underwent one- or two-level LLIF. Preoperative, initial postoperative, and 6-month postoperative measurements of LL, segmental lordosis, anterior disc height, and posterior disc height were collected from standing lateral radiographs for each patient. Cage placement was measured utilizing the center point ratio (CPR) on immediate postoperative radiographs. Spearman correlations were used to assess associations between cage lordosis and radiographic parameters. Multivariate linear regression was performed to assess independent predictors of outcomes. RESULTS: A total of 106 levels in 78 unique patients were included. Most procedures involved fusion of one level (n = 50, 64.1%), most commonly L3-4 (46.2%). Despite no differences in baseline segmental lordosis, patients with anteriorly or centrally placed cages experienced the greatest segmental lordosis correction immediately (mean anterior 4.81° and central 4.46° vs posterior 2.47°, p = 0.0315) and at 6 months postoperatively, and patients with anteriorly placed cages had greater overall lordosis correction postoperatively (mean 6.30°, p = 0.0338). At the 6-month follow-up, patients with anteriorly placed cages experienced the greatest increase in anterior disc height (mean anterior 6.24 mm vs posterior 3.69 mm, p = 0.0122). Cages placed more posteriorly increased the change in posterior disc height postoperatively (mean posterior 4.91 mm vs anterior 1.80 mm, p = 0.0001) and at 6 months (mean posterior 4.18 mm vs anterior 2.06 mm, p = 0.0255). There were no correlations between cage lordotic angle and outcomes. On multivariate regression, anterior cage placement predicted greater 6-month improvement in segmental lordosis, while posterior placement predicted greater 6-month improvement in posterior disc height. Percutaneous screw placement, cage lordotic angle, and cage height did not independently predict any radiographic outcomes. CONCLUSIONS: LLIF procedures reliably improve LL and increase intervertebral disc space. Anterior cage placement improves the lordosis angle greater than posterior placement, which better corrects sagittal alignment, but there is still a significant improvement in lordosis even with a posteriorly placed cage. Posterior cage placement provides greater restoration in posterior disc space height, maximizing indirect decompression, but even the anteriorly placed cages provided indirect decompression. Cage parameters including cage height, lordosis angle, and material do not impact radiographic improvement.

The surgical algorithm for the AOSpine thoracolumbar spine injury classification system.

PURPOSE: The goal of the current study is to establish a surgical algorithm to accompany the AOSpine thoracolumbar spine injury classification system. METHODS: A survey was sent to AOSpine members from the six AO regions of the world, and surgeons were asked if a patient should undergo an initial trial of conservative management or if surgical management was warranted. The survey consisted of controversial injury patterns. Using the results of the survey, a surgical algorithm was developed. RESULTS: The AOSpine Trauma Knowledge forum defined that the injuries in which less than 30% of surgeons would recommend surgical intervention should undergo a trial of non-operative care, and injuries in which 70% of surgeons would recommend surgery should undergo surgical intervention. Using these thresholds, it was determined that injuries with a thoracolumbar AOSpine injury score (TL AOSIS) of three or less should undergo a trial of conservative treatment, and injuries with a TL AOSIS of more than five should undergo surgical intervention. Operative or non-operative treatment is acceptable for injuries with a TL AOSIS of four or five. CONCLUSION: The current algorithm uses a meaningful injury classification and worldwide surgeon input to determine the initial treatment recommendation for thoracolumbar injuries. This allows for a globally accepted surgical algorithm for the treatment of thoracolumbar trauma.

Fusion in degenerative spondylolisthesis: comparison of osteoconductive and osteoinductive bone graft substitutes.

INTRODUCTION: The emergent widespread options of bone graft substitutes for spinal fusion procedures vary in their osteobiologic activity. A majority of current literature focuses on the comparison of osteoinductive (OI) or osteoconductive (OC) bone graft substitutes individually against ICBG. These studies have demonstrated the legitimacy of bone graft substitutes, but despite the widespread use in spinal fusion procedures there is a dearth in the current literature in the direct comparison of OC and OI substitutes. This retrospective comparative analysis compares the efficacy of OI vs. solely OC agents in producing radiographic fusion on patients with DS. METHODS: Patients, who underwent a lumbar fusion for DS with at least 6 months post-op radiographs, were divided based on whether they received an OC or OI bone graft substitute. The OC groups included allografts, calcium phosphate, ceramics and hydroxyapatite products. The OI group included bone morphogenic protein, demineralized bone matrix, and stem cell-based products. MEASUREMENT CRITERIA: Using a conservative hierarchical approach to determine fusion, fusion criteria included stringent use of multiple measurement methods including flexion/extension x-rays, Lenke and Brantigan CT fusion measurement criteria, and history of revision surgery due to pseudoarthrosis. RESULTS: A total of 126 patients (78 OI, 48 OC) met the studies inclusion criteria for the assessment for fusion. The mean time for flexion-extension radiographic evaluation was 13.1 months for the OI group and 15 months for the OC group. The mean time for CT scan evaluation was 18 months for the OI group and 15.9 months for the OC group. Using the stated hierarchical criteria for fusion stated above, the fusion rate for the OI group was 87.18%, and the fusion rate for the OC group was 93.75%. The difference in OI and OC groups was not statistically significant (P = 0.367). Based on the demographic data collected, there were no statistically significant factors determining fusion. CONCLUSION: With the vastly growing market for OI and OC materials commonly used in lumbar spinal fusions, the options for surgical treatment for degenerative spondylolisthesis are ever expanding. No significant difference was found when comparing fusion rates between the two types of materials in this retrospective analysis. Interestingly, TLIF procedures provided lower fusion rates than posterolateral fusion procedures. This may be due to a small sample size but the association with a minimally invasive technique warrants investigation. Due to the substantial difference in price between the OI and OC materials and the lack of evidence supporting higher fusion rates with more expensive OI agents, it is incumbent on the spine community to consider and reassess the products that are routinely used.

Routine Upright Imaging for Evaluating Degenerative Lumbar Stenosis: Incidence of Degenerative Spondylolisthesis Missed on Supine MRI.

STUDY DESIGN: A retrospective cohort. BACKGROUND: Degenerative spondylolisthesis (DS) with lumbar stenosis is a well-studied pathology and diagnosis is most commonly determined by a combination of magnetic resonance imaging (MRI) and standing radiographs. However, routine upright imaging is not universally accepted as standard in all practices. To the best of our knowledge, there has been no study investigating the incidence of missed diagnosis of DS evident only on standing lateral or dynamic radiographs when compared with sagittal alignment on MRI. OBJECTIVE: The authors hypothesize that supine MRI evaluation alone in lumbar degenerative disease will significantly underestimate the incidence of DS. Secondary hypothesis is that there will be no significant difference in detecting spondylolisthesis when comparing dynamic flexion-extension radiographs to standing lateral radiographs. METHODS: We retrospectively evaluated all patients presenting to spine clinic for degenerative lumbar conditions from July 2004 to July 2006 who had an MRI, upright lateral, and flexion-extension radiographs at our institution. The incidence of DS found on dynamic flexion-extension radiographs but not on MRI was determined. We then reviewed each and compared flexion-extension versus standing lateral views to determine whether there was any significant difference in detecting anterolisthesis. RESULTS: Of 416 patients with eligible studies, 109 were found to have DS at levels L4-L5, L5-S1, or L3-L4 based on flexion-extension radiographs. Of these, only 78 were found to have a corresponding spondylolisthesis on MRI, leaving 31/109 (28%) of DS levels undiagnosed on MRI. No additional anterolisthesis cases were detected on standing flexion-extension verses standing lateral radiographs. CONCLUSIONS: Routine standing lateral radiographs should be standard practice to identify DS, as nearly 1/3 of cases will be missed on supine MRI. This may have implications on whether or not an arthrodesis is performed on those patients requiring lumbar decompression. Flexion-extension radiographs demonstrated no added value compared with standing lateral x-rays for the purposes of diagnosing DS.

Lateral Mass Fixation in the Subaxial Cervical Spine.

The use of lateral mass screws and rods in the subaxial spine has become the standard method of fixation for posterior cervical spine fusions. Multiple techniques have been described for the placement of lateral mass screws, including the Magerl, the Anderson, and the An techniques. While these techniques are all slightly different, the overall goal is to obtain solid bony fixation while avoiding the neurovascular structures. The use of lateral mass screws has been shown to be a safe and effective technique for achieving a posterior cervical fusion.

Postoperative Epidural Hematomas in the Lumbar Spine.

Postoperative epidural hematomas are rare complications following lumbar spine surgery, but if they are not quickly identified and treated they can lead to permanent neurological deficits. Epidural hematomas occur in approximately 0.10%-0.24% of all spine surgeries, and despite the fact that multiple large studies have been performed attempting to identify risk factors for this complication, there is still significant debate about the effect of subfascial drains, postoperative anticoagulation, and antiplatelet medication on the incidence of postoperative hematoma. The purpose of this manuscript is to review the epidemiology, etiology, diagnosis, and treatment of patients who develop a postoperative lumbar epidural hematoma.

Surgical treatment for ossification of the posterior longitudinal ligament in the cervical spine.

Although classically associated with patients of East Asian origin, ossification of the posterior longitudinal ligament (OPLL) may cause myelopathy in patients of any ethnic origin. Degeneration of the PLL is followed by endochondral ossification, resulting in spinal cord compression. Specific genetic polymorphisms and medical comorbidities have been implicated in the development of OPLL. Patients should be evaluated with a full history and neurologic examination, along with cervical radiographs. Advanced imaging with CT and MRI allows three-dimensional evaluation of OPLL. Minimally symptomatic patients can be treated nonsurgically, but patients with myelopathy or severe stenosis are best treated with surgical decompression. OPLL can be treated via an anterior (ie, corpectomy and fusion) or posterior (ie, laminectomy and fusion or laminoplasty) approach, or both. The optimal approach is dictated by the classification and extent of OPLL, cervical spine sagittal alignment, severity of stenosis, and history of previous surgery. Anterior surgery is associated with superior outcomes when OPLL occupies >50% to 60% of the canal, despite increased technical difficulty and higher complication rates. Posterior surgery is technically easier and allows decompression of the entire cervical spine, but patients may experience late deterioration because of disease progression.

Timing of surgery in thoracolumbar trauma: is early intervention safe?

The understanding of the optimal surgical timing for stabilization in thoracolumbar fractures is severely limited. Thoracolumbar spine fractures can be devastating injuries and are often associated with significant morbidity and mortality. The role of early surgical stabilization (within 48-72 hours of injury) as a vehicle to improve outcomes in these patients has generated significant interest. Goals of early stabilization include improved neurological recovery, faster pulmonary recovery, improved pain control, and decreased health care costs. Opponents cite the potential for increased bleeding, hypotension, and the risk of further cord injury as a few factors that weigh against early stabilization. The concept of spinal cord injury and its relationship to surgical timing remains in question. However, when neurological outcomes are eliminated from the equation, certain measures have shown positive influences from prompt surgical fixation. Early fixation of thoracolumbar spine fractures can significantly decrease the duration of hospital stay and the number of days in the intensive care unit. Additionally, prompt stabilization can reduce rates of pulmonary complications. This includes decreased rates of pneumonia and fewer days on ventilator support. Cost analysis revealed as much as $80,000 in savings per patient with early stabilization. All of these benefits come without an increase in morbidity or evidence of increased mortality. In addition, there is no evidence that early stabilization has any ill effect on the injured or uninjured spinal cord. Based on the existing data, early fixation of thoracolumbar fractures has been linked with positive outcomes without clear evidence of negative impacts on the patient's neurological status, associated morbidities, or mortality. These procedures can be viewed as "damage control" and may consist of simple posterior instrumentation or open reductions with internal fixation as indicated. Based on the current literature it is advisable to proceed with early surgical stabilization of thoracolumbar fractures in a well-resuscitated patient, unless extenuating medical conditions would prevent it.

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.

The Effect of Patient Resilience on Postoperative Scores After One- and Two-Level Anterior Cervical Discectomy and Fusion.

OBJECTIVE: To investigate the association between resilience and outcomes of pain and neck-related disability after single- and double-level anterior cervical discectomy and fusion (ACDF). METHODS: Patients who underwent single- or double-level ACDF were sent a survey between 6 months and 2 years after surgery. The survey included the Brief Resilience Scale (BRS), visual analogue scale (VAS) for pain, Neck Disability Index (NDI), and Pain Self-Efficacy Questionnaire (PSEQ-2). Patients completed the VAS and NDI twice, once describing preoperative pain and disability and once describing current pain and disability. Respondents were classified as high resilience (HR), medium resilience (MR), or low resilience (LR). Demographics, PSEQ-2 scores, pre- and postoperative VAS and NDI scores, and change in VAS (ΔVAS) and NDI (ΔNDI) scores were compared between groups. RESULTS: Thirty-three patients comprised the HR group, 273 patients comprised the MR group, and 47 patients comprised the LR group. All groups demonstrated postoperative improvement in VAS and NDI scores that exceeded previously established MCID values. The HR group demonstrated greater improvement in pain compared with the LR group (ΔVAS: -5.8 for HR vs. -4.4 for LR, P = 0.05). Compared with the MR group, the LR group demonstrated greater postoperative pain (VAS: 3.2 for LR vs. 2.5 for MR, P = 0.02) and disability (NDI: 11.9 for LR vs. 8.6 for MR, P = 0.02). CONCLUSIONS: Patients demonstrated improvement in pain and neck-related disability after single- and double-level ACDF, regardless of resilience score. Patients with greater resilience may be expected to demonstrate more improvement in pain after ACDF.

Impact of Weekday on Short-term Surgical Outcomes After Lumbar Fusion Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The purpose of this study is to investigate whether weekday lumbar spine fusion surgery has an impact on surgical and inpatient physical therapy (PT) outcomes. SUMMARY OF BACKGROUND DATA: Timing of surgery has been implicated as a factor that may impact outcomes after spine surgery. Previous literature suggests that there may be an adverse effect to having surgery on the weekend. METHODS: All patients ≥18 years who underwent primary lumbar spinal fusion from 2014 to 2020 were retrospectively identified. Patients were subdivided into an early subgroup (surgery between Monday and Wednesday) and a late subgroup (surgery between Thursday and Friday). Surgical outcome variables included inpatient complications, 90-day readmissions, and 1-year revisions. PT data from the first inpatient PT session included hours to PT session, AM-PAC Daily Activity or Basic Mobility scores, and total gait trial distance achieved. RESULTS: Of the 1239 patients identified, 839 had surgery between Monday and Wednesday and 400 had surgery between Thursday and Friday. Patients in the later surgery subgroup were more likely to experience a nonsurgical neurologic complication (3.08% vs. 0.86%, P=0.008); however, there was no difference in total complications. Patients in the early surgery subgroup had their first inpatient PT session earlier than patients in the late subgroup (15.7 vs. 18.9 h, P<0.001). However, patients in the late subgroup achieved a farther total gait distance (98.2 vs. 75.4, P=0.011). Late surgery was a significant predictor of more hours of PT (est.=0.256, P=0.016) and longer length of stay (est.=2.277, P=0.001). There were no significant differences in readmission and revision rates. CONCLUSIONS: Patients who undergo surgery later in the week may experience more nonsurgical neurologic complications, longer wait times for inpatient PT appointments, and longer lengths of stay. This analysis showed no adverse effect of later weekday surgery as it relates to total complications, readmissions, and reoperations. LEVEL OF EVIDENCE: Level III.

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.

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 Effect of Muscle Quality on Outcomes after Microdiscectomy.

OBJECTIVES: To investigate the relationship between muscle quality and 1) patient-reported outcomes and 2) surgical outcomes after lumbar microdiscectomy surgery. METHODS: Adult patients (≥18 years) who underwent lumbar microdiscectomy from 2014 to 2021 at a single academic institution were identified. Outcomes were collected during the preoperative, 3-month, 6-month, and 1-year postoperative periods. Those included were 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). Muscle quality was determined by 2 systems: the normalized total psoas area (NTPA) and a paralumbar-based grading system. Surgical outcomes including 90-day surgical readmissions and 1-year reoperations were also collected. RESULTS: Of the 218 patients identified, 150 had good paralumbar muscle quality and 165 had good psoas muscle quality. Bivariant analysis demonstrated no difference between groups regarding surgical outcomes (P > 0.05). Multivariable analysis demonstrated that better paralumbar muscle quality was not associated with any consistent changes in patient reported outcomes. Higher NTPA was associated with improved PCS at 6 months (est. = 6.703, [95% CI: 0.759-12.646], P = 0.030) and 12 months (est. = 6.625, [95% CI: 0.845-12.405], P = 0.027). There was no association between muscle quality and surgical readmissions or reoperations. CONCLUSIONS: Our analysis demonstrated that higher psoas muscle quality was associated with greater physical improvement postoperatively. Muscle quality did not affect surgical readmissions or reoperations. Additional studies are needed for further assessment of the implications of muscle quality on postoperative outcomes.

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.

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.

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.