Long-term radiographic and endocrinological outcomes of stereotactic radiosurgery for recurrent or residual nonfunctioning pituitary adenomas.

OBJECTIVE: Stereotactic radiosurgery (SRS) is used for the treatment of residual/recurrent nonfunctional pituitary adenoma (NFPA). The aim of this study was to evaluate the factors related to long-term tumor control and delayed endocrinopathies following SRS. METHODS: This retrospective, multicenter study included patients with recurrent/residual NFPA treated with single-fraction SRS; they were then divided into two arms. The first arm included patients with at least 5 years of radiographic follow-up and all patients with local tumor progression. The second arm included patients with at least 5 years of endocrinological follow-up and all patients who developed endocrinopathy. Study endpoints were tumor control and new or worsening hypopituitarism after SRS and were analyzed using Cox regression and Kaplan-Meier methodology. RESULTS: There were 360 patients in the tumor control arm (median age 52.7 [IQR 42.9-61] years, 193 [53.6%] males) and 351 patients in the hypopituitarism arm (median age 52.5 [IQR 43-61] years, 186 [53.0%] males). The median follow-up in the tumor control evaluation group was 7.95 (IQR 5.7-10.5) years. Tumor control rates at 5, 8, 10, and 15 years were 93% (95% CI 90%-95%), 87% (95% CI 83%-91%), 86% (95% CI 82%-90%), and 69% (95% CI 59%-81%), respectively. The median follow-up in the endocrinopathy evaluation group was 8 (IQR 5.9-10.7) years. Pituitary function preservation rates at 5, 8, 10, and 15 years were 83% (95% CI 80%-87%), 81% (95% CI 77%-85%), 78% (95% CI 74%-83%), and 71% (95% CI 63%-79%), respectively. A margin dose > 15 Gy (HR 0.8, 95% CI 0.7-0.9; p < 0.001) and a delay from last resection to SRS > 1 year (HR 0.9, 95% CI 0.7-0.9; p = 0.04) were significant factors related to tumor control in multivariable analysis. A maximum dose to the pituitary stalk ≤ 10 Gy (HR 1.1, 95% CI 1.09-1.2; p < 0.001) was associated with pituitary function preservation. New visual deficits after SRS occurred in 7 (1.94%) patients in the tumor control group and 8 (2.3%) patients in the endocrinopathy group. Other new cranial nerve deficits post-SRS occurred in 4 of 160 patients with data in the tumor control group and 3 of 140 patients with data in the endocrinopathy group. CONCLUSIONS: SRS affords favorable and durable tumor control for the vast majority of NFPAs. Post-SRS hypopituitarism occurs in a minority of patients, but this risk increases with time and warrants long-term follow-up.

Anatomical and Technical Considerations of Robot-Assisted Cervical Pedicle Screw Placement: A Cadaveric Study.

STUDY DESIGN: Cadaver study. OBJECTIVES: Assess the feasibility of robot-assisted cervical pedicle screw (RA-CPS) placement and understand the anatomical considerations of this technique. METHODS: Four cadaver specimens free from bony pathology were acquired. Anatomical considerations, such as pedicle width (PW) and height (PH), transverse pedicle angle (TPA), and maximal screw length (MSL), were recorded from preoperative computational tomography (CT) scans. Intraoperative cone-beam CT was acquired and registered to the robotic system. After cervical levels were segmented, screw sizes and trajectories were planned, and RA-CPS were placed. Accuracy was assessed using Gertzbein and Robbin's classification on postoperative CT scans. RESULTS: Thirty-five RA-CPS were placed. Major breaches (≥Grade C) occurred in 28.57% screws. Grade A or B accuracy was found in 71.43% of screws, with the most common direction of breach being medial (81.3%). The greatest proportion of breach per level occurred in the upper subaxial levels, (C3:71.4%, C4 66.6%, C5:50%) which had the smallest PW (C3: 4.34 ± .96 mm, C4: 4.48 ± .60, C5: 5.76 ± 1.11). PH was greatest at C2 (8.14 ± 1.89 mm) and ranged subaxial from 6.36 mm (C3) to 7.48 mm (C7). The mean PW was 5.37 mm and increased caudally from 4.34 mm (C3) to 6.31 mm (C7). The mean TPA was 39.9° and decreased moving caudally 46.9°) to C7 (34.4°). The MSL was 37.1 mm and increased from C2 (26.3 mm) to C7 (41.0 mm). CONCLUSION: RA-CPS has the potential to be feasible, but technological and instrument modifications are necessary to increase the accuracy in the cervical region.

The Impact of Preoperative Symptom Duration on Patient Outcomes After Posterior Cervical Decompression and Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine if decreased preoperative symptom duration is associated with greater clinical improvement in function and myelopathic symptoms after posterior cervical decompression and fusion (PCDF). METHODS: All patients over age 18 who underwent primary PCDF for cervical myelopathy or myeloradiculopathy at a single institution between 2014 and 2020 were retrospectively identified. Patient demographics, surgical characteristics, duration of symptoms, and preoperative and postoperative patient reported outcomes measures (PROMs) including modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), Visual Analogue Scale (VAS) Neck, VAS Arm, and SF-12 were collected. Univariate and multivariate analyses were performed to compare change in PROMs and minimum clinically important difference achievement (%MCID) between symptom duration groups (< 6 months, 6 months-2 years, > 2 years). RESULTS: Preoperative symptom duration groups differed significantly by sex and smoking status. Patients with < 6 months of preoperative symptoms improved significantly in all PROMs. Patients with 6 months-2 years of preoperative symptoms did not improve significantly in mJOA, Physical Component Scores (PCS), or NDI. Patients with > 2 years of symptoms failed to demonstrate significant improvement in mJOA, NDI, or Mental Component Scores (MCS). Univariate analysis demonstrated significantly decreased improvement in mJOA with longer symptom durations. Increased preoperative symptom duration trended toward decreased %MCID for mJOA and MCS. Regression analysis demonstrated that preoperative symptom duration of > 2 years relative to < 6 months predicted decreased improvement in mJOA and NDI and decreased MCID achievement for mJOA and MCS. CONCLUSION: Increased duration of preoperative symptoms (> 2 years) before undergoing PCDF was associated with decreased postoperative improvement in myelopathic symptoms.

CT-to-fluoroscopy registration versus scan-and-plan registration for robot-assisted insertion of lumbar pedicle screws.

OBJECTIVE: Pedicle screw insertion for stabilization after lumbar fusion surgery is commonly performed by spine surgeons. With the advent of navigation technology, the accuracy of pedicle screw insertion has increased. Robotic guidance has revolutionized the placement of pedicle screws with 2 distinct radiographic registration methods, the scan-and-plan method and CT-to-fluoroscopy method. In this study, the authors aimed to compare the accuracy and safety of these methods. METHODS: A retrospective chart review was conducted at 2 centers to obtain operative data for consecutive patients who underwent robot-assisted lumbar pedicle screw placement. The newest robotic platform (Mazor X Robotic System) was used in all cases. One center used the scan-and-plan registration method, and the other used CT-to-fluoroscopy for registration. Screw accuracy was determined by applying the Gertzbein-Robbins scale. Fluoroscopic exposure times were collected from radiology reports. RESULTS: Overall, 268 patients underwent pedicle screw insertion, 126 patients with scan-and-plan registration and 142 with CT-to-fluoroscopy registration. In the scan-and-plan cohort, 450 screws were inserted across 266 spinal levels (mean 1.7 ± 1.1 screws/level), with 446 (99.1%) screws classified as Gertzbein-Robbins grade A (within the pedicle) and 4 (0.9%) as grade B (< 2-mm deviation). In the CT-to-fluoroscopy cohort, 574 screws were inserted across 280 lumbar spinal levels (mean 2.05 ± 1.7 screws/ level), with 563 (98.1%) grade A screws and 11 (1.9%) grade B (p = 0.17). The scan-and-plan cohort had nonsignificantly less fluoroscopic exposure per screw than the CT-to-fluoroscopy cohort (12 ± 13 seconds vs 11.1 ± 7 seconds, p = 0.3). CONCLUSIONS: Both scan-and-plan registration and CT-to-fluoroscopy registration methods were safe, accurate, and had similar fluoroscopy time exposure overall.

Outcomes following surgical treatment of distal radial fracture: a comparison of older and younger patients using PROMIS.

The purpose of this study was to assess the recovery patterns following surgery for distal radial fracture (DRF) in patients over (n = 99) and under (n = 273) the age of 65 using the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) questionnaires. Both the older and younger cohorts showed postoperative improvement in PF and PI. The younger cohort had higher PF scores from 1 to 6 months postoperatively, however, PI scores were not significantly different between the cohorts during any period. A greater proportion of younger patients achieved the minimal clinically important difference improvement on the PROMIS PF (80% versus 66%) and PI (88% versus 75%) scales. To appropriately manage postoperative expectations, older patients should be counselled that they would likely experience most of their functional recovery by 3 months and limitations due to pain would likely be stable by 1 month.Level of evidence: II.

Overview of Traumatic Brain Injury in American Football Athletes.

OBJECTIVE: The aim of this review is to provide a summary of the epidemiology, clinical presentation, pathophysiology, and treatment of traumatic brain injury in collision athletes, particularly those participating in American football. DATA SOURCES: A literature search was conducted using the PubMed/MEDLINE and Google Scholar databases for publications between 1990 and 2019. The following search phrases were used: "concussion," "professional athletes," "collision athletes," "mild traumatic brain injury," "severe traumatic brain injury," "management of concussion," "management of severe traumatic brain injury," and "chronic traumatic encephalopathy." Publications that did not present epidemiology, clinical presentation, pathophysiology, radiological evaluation, or management were omitted. Classic articles as per senior author recommendations were retrieved through reference review. RESULTS: The results of the literature review yielded 147 references: 21 articles discussing epidemiology, 16 discussing clinical presentation, 34 discussing etiology and pathophysiology, 10 discussing radiological evaluation, 34 articles for on-field management, and 32 articles for medical and surgical management. CONCLUSION: Traumatic brain injuries are frequent in professional collision athletes, and more severe injuries can have devastating and lasting consequences. Although sport-related concussions are well studied in professional American football, there is limited literature on the epidemiology and management of severe traumatic brain injuries. This article reviews the epidemiology, as well as the current practices in sideline evaluation, acute management, and surgical treatment of concussions and severe traumatic brain injury in professional collision athletes. Return-to-play decisions should be based on individual patient symptoms and recovery.

Comparison of Outcomes Including or Excluding the Level of Listhesis After ACDF in the Setting of Degenerative Spondylolisthesis.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The goal of this study is to evaluate the outcomes of patients with cervical degenerative spondylolisthesis (DS) undergoing anterior cervical discectomy and fusion (ACDF), specifically comparing surgeries that include versus exclude the DS level. SUMMARY OF BACKGROUND DATA: DS has been extensively studied in the lumbar spine associated with both back and leg pain leading to worse patient quality of life measures. Conversely, there is a relative dearth of literature regarding surgical and clinical outcomes in the setting of cervical DS. MATERIALS AND METHODS: A total of 315 patients undergoing ACDF between 2014 and 2018 with minimum of 1-year postoperative patient-reported outcome measures (PROMs) were retrospectively reviewed. Forty-six patients were found to have DS and were categorized based on whether an ACDF was performed at the same level (SL) or at a different level (DL) than the spondylolisthesis. Patient demographics, surgical parameters, preoperative and postoperative radiographs, and PROMs were compared between groups. RESULTS: Of the 315 patients, a total of 46 met the inclusion criteria including 21 SL and 25 DL patients. There were no significant differences in patient demographics between the groups. The SL cohort had a significantly worse preoperative sagittal vertical axis (SL: 34.4 vs. 26.1, P=0.025) but no difference in postoperative or delta sagittal vertical axis. Both patient cohorts reported significant postoperative improvement in all PROMs, except Short-Form 12 Mental Component Score in the SL group. There were no differences between the groups regarding Visual Analog Scale Neck, Visual Analog Scale Arm, Neck Disability Index, or Short-Form 12 Physical Component Score. Regression analysis demonstrated SL to be a significant negative predictor for improvement in Short-Form 12 Mental Component Score (ß: -11.27, P=0.10). CONCLUSION: Patients treated only at their neurologically symptomatic levels, excluding asymptomatic listhesis in their construct, can expect equivalent radiographic as well as physical function, disability, and pain outcomes 1 year after ACDF compared with patients whose listhetic level was included in their construct. LEVEL OF EVIDENCE: Level III.

Patients With Preoperative Cervical Deformity Experience Similar Clinical Outcomes to Those Without Deformity Following 1-3 Level Anterior Cervical Decompression and Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim was to compare the outcomes of patients with incompletely corrected cervical deformity against those without deformity following short-segment anterior cervical decompression and fusion for clinically significant radiculopathy or myelopathy. SUMMARY OF BACKGROUND DATA: Cervical deformity has increasingly been recognized as a driver of disability and has been linked to worse patient-reported outcomes measures (PROMs) after surgery. METHODS: Patients 18 years or above who underwent 1-3 level anterior cervical decompression and fusion to address radiculopathy and/or myelopathy at a single institution between 2014 and 2018 with at least 1 year of PROMs were reviewed. Patients were categorized based on cervical deformity into 2 groups: sagittal vertebral axis (cSVA) ≥40 mm as the deformity group, and cSVA <40 mm as the nondeformity group. Patient demographics, surgical parameters, preoperative and postoperative radiographs, and minimum 1-year PROMs were compared. RESULTS: Of the 230 patients, 191 (83%) were in the nondeformity group and 39 (17%) in the deformity group. Patients with deformity were more likely to be male (69.2% vs. 40.3%, P<0.001) and have a greater body mass index (32.8 vs. 29.7, P=0.028). The deformity group had significantly greater postoperative cSVA (44.2 vs. 25.1 mm, P<0.001) but also had significantly greater ∆cSVA (-4.87 vs. 0.25 mm, P=0.007) than the nondeformity group. Both groups had significant improvements in visual analog scale arm, visual analog scale neck, Short-Form 12 Physical Component Score, and neck disability index (NDI) (P<0.001). However, the deformity group experienced significantly greater ∆NDI and ∆mental component score (MCS)-12 scores (-19.45 vs. -11.11, P=0.027 and 7.68 vs. 1.32, P=0.009). CONCLUSIONS: Patients with preoperative cervical sagittal deformity experienced relatively greater improvements in NDI and MCS-12 scores than those without preoperative deformity. These results suggest that complete correction of sagittal alignment is not required for patients to achieve significant clinical improvement. LEVEL OF EVIDENCE: III.

Effect of a Mandatory Prescription Drug Monitoring Program on Patient-initiated Phone Calls After Spine Surgery.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The objective of this study was to determine the effect of a statewide, government-mandated prescription drug monitoring program (PDMP) on patient-initiated phone calls after lumbar and cervical spinal surgery. SUMMARY OF BACKGROUND DATA: Prior studies have examined the most common reasons for a postoperative phone calls, most of which pertain to pain or prescription medications. However, no studies have investigated the effects of mandatory opioid prescription reporting on these calls. METHODS: Patients who underwent lumbar decompression, lumbar fusion, or posterior cervical fusion were retrospectively identified. Patients were sorted into 1 of 2 cohorts based on their procedure date's relation to the initiation of the state's PDMP: "pre-PDMP" and "post-PDMP." All clinical and demographic data were obtained from electronic health records. Telephone communications from or on behalf of patients were retrospectively reviewed. Multivariable logistic regression was performed to determine independent factors associated with a postoperative phone call. RESULTS: Five hundred and twenty-five patients (2689 phone calls) were included in the study. Average number of phone calls per patient increased significantly after PDMP implementation among lumbar (3.27 vs. 5.18, P<0.001), cervical (5.08 vs. 11.67, P<0.001), and all (3.59 vs. 6.30, P<0.001) procedures. Age [odds ratio (OR): 1.05 (1.01, 1.09), P=0.02], cervical procedure [OR: 4.65 (1.93, 11.21), P=0.001], and a post-PDMP date of surgery [OR: 6.35 (3.55, 11.35), P<0.001] were independently associated with an increased likelihood of a postoperative phone call. A higher percentage of calls were in reference to postoperative care (4.6% vs. 2.4%, P=0.01) and wound care (4.3% vs. 1.4%, P<0.001) in the post-PDMP cohort compared with the pre-PDMP cohort. CONCLUSIONS: Patient-initiated telephone calls increased significantly after implementation of a mandatory statewide PDMP. Increasing age, operation involving the cervical spine, and surgery occurring after implementation of the state's PDMP were independently associated with an increased likelihood of postoperative phone call to health care providers.

Ninety-day complication, revision, and readmission rates for current-generation robot-assisted thoracolumbar spinal fusion surgery: results of a multicenter case series.

OBJECTIVE: Robotics is a major area for research and development in spine surgery. The high accuracy of robot-assisted placement of thoracolumbar pedicle screws is documented in the literature. The authors present the largest case series to date evaluating 90-day complication, revision, and readmission rates for robot-assisted spine surgery using the current generation of robotic guidance systems. METHODS: An analysis of a retrospective, multicenter database of open and minimally invasive thoracolumbar instrumented fusion surgeries using the Mazor X or Mazor X Stealth Edition robotic guidance systems was performed. Patients 18 years of age or older and undergoing primary or revision surgery for degenerative spinal conditions were included. Descriptive statistics were used to calculate rates of malpositioned screws requiring revision, as well as overall complication, revision, and readmission rates within 90 days. RESULTS: In total, 799 surgical cases (Mazor X: 48.81%; Mazor X Stealth Edition: 51.19%) were evaluated, involving robot-assisted placement of 4838 pedicle screws. The overall intraoperative complication rate was 3.13%. No intraoperative implant-related complications were encountered. Postoperatively, 129 patients suffered a total of 146 complications by 90 days, representing an incidence of 16.1%. The rate of an unrecognized malpositioned screw resulting in a new postoperative radiculopathy requiring revision surgery was 0.63% (5 cases). Medical and pain-related complications unrelated to hardware placement accounted for the bulk of postoperative complications within 90 days. The overall surgical revision rate at 90 days was 6.63% with 7 implant-related revisions, representing an implant-related revision rate of 0.88%. The 90-day readmission rate was 7.13% with 2 implant-related readmissions, representing an implant-related readmission rate of 0.25% of cases. CONCLUSIONS: The results of this multicenter case series and literature review suggest current-generation robotic guidance systems are associated with low rates of intraoperative and postoperative implant-related complications, revisions, and readmissions at 90 days. Future outcomes-based studies are necessary to evaluate complication, revision, and readmission rates compared to conventional surgery.

The Effect of L5-S1 Degenerative Disc Disease on Outcomes of L4-L5 Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim was to investigate the clinical relevance of preoperative caudal adjacent segment degeneration (ASD) in patients undergoing isolated L4-5 fusion to determine a threshold of degeneration at which a primary L4-S1 fusion would be warranted. SUMMARY OF BACKGROUND DATA: Increased motion and biomechanical forces across the adjacent caudal segment in isolated L4-L5 fusion leads to concerns regarding the increased incidence of revision surgery because of the development of ASD. METHODS: Patients who underwent isolated L4-L5 fusion between 2014 and 2019 were reviewed. Pfirrmann grading and the disc heights of the caudal level relative to the rostral level were used to quantify preoperative adjacent degenerative disc disease. To assess the influence of preoperative caudal degenerative disc disease, preoperative disc height ratios (DHRs) were compared for patients who reported minimal, moderate, and severe Oswestry disability index (ODI) sores on postoperative assessment. For each patient-reported outcome measure (PROM), adjacent DDD was compared for those who did and did not meet MCID. An area under curve analysis was used to identify a threshold of degeneration impacting outcomes from the preoperative DHR. RESULTS: A total of 123 patients were studied with an average follow-up of 2.11 years. All patients demonstrated a significant improvement in all PROMs after surgery. When categorizing patients based on the severity of postoperative ODI scores, there were no preoperative differences in the L5-S1 Pfirrmann grading or DHRs. There was a significant association between greater preoperative anterior DHR and an increased number patients who met MCID for visual analog scale back. There were no radiographic differences in preoperative L5-S1 Pfirrmann grade or DHR for ODI, visual analog scale leg, MCS-12, or PCS-12. area under curve analysis was not able to identify a preoperative DHR threshold that reflected worse MCID for any PROM. CONCLUSION: No preoperative radiographic indicators of caudal ASD were predictive of worse clinical outcomes after isolated L4-5 fusion. LEVEL OF EVIDENCE: Level III.

Reimbursement of Lumbar Decompression at an Orthopedic Specialty Hospital Versus Tertiary Referral Center.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to investigate the differences in Medicare reimbursement for one- to three-level lumbar decompression procedures performed at a tertiary referral center versus an orthopedic specialty hospital (OSH). SUMMARY OF BACKGROUND DATA: Lumbar decompression surgery is one of the most commonly performed spinal procedures. Lumbar decompression also comprises the largest proportion of spinal surgery that has transitioned to the outpatient setting. METHODS: Patients who underwent a primary one- to three- level lumbar decompression were retrospectively identified. Reimbursement data for a tertiary referral center and an OSH were compiled through Centers for Medicare and Medicaid Services. Demographic data, surgical characteristics, and time cost data were collected through chart review. Multivariate regression models were used to determine independent factors associated with total episode of care cost, operating room (OR) time, procedure time, and length of stay (LOS), and to determine independent predictors of having the decompression performed at the OSH. RESULTS: Total episode of care, facility, and non-facility payments were significantly greater at the tertiary referral center than the OSH, as were OR time for one- to three-level procedures, procedure time of all pooled levels, and LOS for one- and two-level procedures. Three-level procedure was independently associated with increased OR time, procedure time, and LOS. Age and two-level procedure were also associated with increased LOS. Procedure at the OSH was associated with decreased OR time and LOS. Charlson Comorbidity Index was a negative predictor of decompression being performed in the OSH setting. CONCLUSION: Significant financial savings to health systems can be expected when performing lumbar decompression surgery at a specialty hospital as opposed to a tertiary referral center. Patients who are appropriate candidates for surgery in an OSH can in turn expect faster perioperative times and shorter LOS.Level of Evidence: 3.

Predictors of Prolonged Opioid Use After Lumbar Fusion and the Effects of Opioid Use on Patient-Reported Outcome Measures.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To determine risk factors associated with prolonged opioid use after lumbar fusion and to elucidate the effect of opioid use on patient-reported outcome measures (PROMs) after surgery. METHODS: Patients who underwent 1-3 level lumbar decompression and fusion with at least one-year follow-up were identified. Opioid data were collected through the Pennsylvania Prescription Drug Monitoring Program. Preoperative "chronic use" was defined as consumption of >90 days in the one-year before surgery. Postoperative "prolonged use" was defined as a filled prescription 90-days after surgery. PROMs included the following: Short Form-12 Health Survey PCS-12 and MCS-12, ODI, and VAS-Back and Leg scores. Logistic regression was performed to determine independent predictors for prolonged opioid use. RESULTS: The final analysis included 260 patients. BMI >35 (OR: .44 [.20, .90], P = .03) and current smoking status (OR: 2.73 [1.14, 6.96], P = .03) significantly predicted postoperative opioid usage. Chronic opioid use before surgery was associated with greater improvements in MCS-12 (ß= 5.26 [1.01, 9.56], P = .02). Patients with prolonged opioid use self-reported worse VAS-Back (3.4 vs 2.1, P = .003) and VAS-Leg (2.6 vs 1.2, P = .03) scores after surgery. Prolonged opioid use was associated with decreased improvement in VAS-Leg over time (ß = .14 [.15, 1.85], P = .02). CONCLUSIONS: Current smoking status and lower BMI were significantly predictive of prolonged opioid use. Excess opioid use before and after surgery significantly affected PROMs after lumbar fusion.

Circumferential fusion with open versus percutaneous posterior fusion for lumbar isthmic spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To investigate the clinical and radiographic differences between patients who underwent anterior lumber interbody fusion (ALIF) with either open or percutaneous posterior fusion for lumbar isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: Circumferential fusion for isthmic spondylolisthesis is commonly performed with superior clinical outcomes, fusion rates, and restoration of sagittal balance when compared to posterior fusion alone. The outcomes comparing traditional open versus percutaneous posterior fusion in this setting have not been fully evaluated. METHODS: A retrospective review of patients who underwent ALIF with either traditional open or percutaneous posterior fusion for isthmic spondylolisthesis between 2014 and 2019 was conducted. Patient demographics, surgical characteristics, and radiographic and clinical outcomes were compared between groups. RESULTS: A total of 79 patients were included in the final analysis, with 49 in the Open group and 30 in the Percutaneous group. No differences were found with regard to demographic factors between groups including sex, body mass index (BMI), diabetic status, and smoking status. The percutaneous group had less estimated blood loss (EBL, 69.2 mL) and shorter length of stay (3.06 days) compared to the open group (446 mL, p = 0.017; 3.98 days, p = 0.003). Both groups demonstrated significant improvement in all clinical outcome measures after surgery (PCS-12, MCS-12, ODI, VAS Back, and VAS Leg scores). The percutaneous group achieved greater ∆VAS Back (Open = 3.55, Perc = 5.17; p = 0.045) and also had a significantly greater improvements in recovery ratio for VAS Back (Open: 0.43, Perc: 0.73; p = 0.037) and ODI (Open: 0.40, Perc = 0.67; p = 0.031). Regression analysis demonstrated percutaneous surgery to be significant predictor of superior improvement in VAS Back scores (ß = 1.957, p = 0.027). CONCLUSION: ALIF with percutaneous posterior fusion affords greater improvement in back pain and disability when compared to ALIF with open posterior fusion for isthmic spondylolisthesis. LEVEL OF EVIDENCE: III.

The effect of COVID-19 on trainee operative experience at a multihospital academic neurosurgical practice: A first look at case numbers.

BACKGROUND: COVID-19 has had a significant impact on the economy, health care, and society as a whole. To prevent the spread of infection, local governments across the United States issued mandatory lockdowns and stay-at-home orders. In the surgical world, elective cases ceased to help "flatten the curve" and prevent the infection from spreading to hospital staff and patients. We explored the effect of the cancellation of these procedures on trainee operative experience at our high-volume, multihospital neurosurgical practice. METHODS: Our department cancelled all elective cases starting March 16, 2020, and resumed elective surgical and endovascular procedures on May 11, 2020. We retrospectively reviewed case volumes for 54 days prelockdown and 54 days postlockdown to evaluate the extent of the decrease in surgical volume at our institution. Procedure data were collected and then divided into cranial, spine, functional, peripheral nerve, pediatrics, and endovascular categories. RESULTS: Mean total cases per day in the prelockdown group were 12.26 ± 7.7, whereas in the postlockdown group, this dropped to 7.78 ± 5.5 (P = 0.01). In the spine category, mean cases per day in the prelockdown group were 3.13 ± 2.63; in the postlockdown group, this dropped to 0.96 ± 1.36 (P < 0.001). In the functional category, mean cases per day in the prelockdown group were 1.31 ± 1.51, whereas in the postlockdown group, this dropped to 0.11 ± 0.42 (P < 0.001). For cranial (P = 0.245), peripheral nerve (P = 0.16), pediatrics (P = 0.34), and endovascular (P = 0.48) cases, the volumes dropped but were not statistically significant decreases. CONCLUSION: The impact of this outbreak on operative training does appear to be significant based solely on statistics. Although the drop in case volumes during this time can be accounted for by the pandemic, it is important to understand that this is a multifactorial effect. Further studies are needed for these results to be generalizable and to fully understand the effect this pandemic has had on trainee operative experience.

Use of the Scan-and-Plan Workflow in Next-Generation Robot-Assisted Pedicle Screw Insertion: Retrospective Cohort Study and Literature Review.

OBJECTIVE: To report our experience using the scan-and-plan workflow and review current literature on surgical efficiency, safety, and accuracy of next-generation robot-assisted (RA) spine surgery. METHODS: The records of patients who underwent RA pedicle screw fixation were reviewed. The accuracy of pedicle screw placement was determined based on the Ravi classification system. To evaluate workflow efficiency, 3 demographically matched cohorts were created to analyze differences in time per screw placement (defined as operating room [OR] time divided by number of screws placed). Group A had <4 screws placed, Group B had 4 screws placed, and Group C had >4 screws placed. Intraoperative errors and postoperative complications were collected to elucidate safety. RESULTS: Eighty-four RA cases (306 pedicle screws) were included for analysis. The mean number of screws placed was 2.1 ± 0.3 in Group A and 6.4 ± 1.2 in Group C; 4 screws were placed in Group B patients. The accuracy rate (Ravi grade I) was 98.4%. Screw placement time was significantly longer in Group A (101 ± 37.7 minutes) than Group B (50.5 ± 25.4 minutes) or C (43.6 ± 14.7 minutes). There were no intraoperative complications, robot failures, or in-hospital complications requiring a return to the OR. CONCLUSIONS: The scan-and-plan workflow allowed for a high degree of accuracy. It was a safe method that provided a smooth and efficient OR workflow without registration errors or robotic failures. After the placement of 4 pedicle screws, the per-screw time remained constant. Further studies regarding efficiency and utility in multilevel procedures are necessary.

Mazor X Stealth Robotic Technology: A Technical Note.

BACKGROUND: Minimally invasive techniques in spine surgery have continued to advance as robotic technology has evolved over several generations. Although traditional techniques for placing pedicle screws are still widespread in practice, newer technology has increased the reliability of accurately placing instrumentation with smaller incisions and subsequent decreased length of stay. Additionally, advancements in planning software have improved the ability to align posterior instrumentation to assist with rod placement on multilevel constructs. METHODS: This paper describes the surgical techniques and operative workflow for placing pedicle screws with the latest robotic technology. The robotic platform, registration, surgical planning, and placement of instrumentation are discussed in detail. Advantages of the Mazor X Stealth Edition compared with the previous generation robot include obviating the need for K wires and eliminating the need for a percutaneous pin, as navigation is integrated into the robot. RESULTS: Our use of this new technology has been encouraging. Using the techniques described in this paper, the first 90 pedicle screws placed with the Mazor X Stealth Edition robot yielded 100% grade A accuracy on the Gertzbein-Robbins scale confirmed on immediate postoperative CT. There were no complications experienced in any case. CONCLUSIONS: In our experience, this robotic technology has the potential to improve patient outcomes and is associated with advanced surgical planning compared with more traditional techniques.

Assessment of Rod Material Types in Spine Surgery Outcomes: A Systematic Review.

BACKGROUND: Lumbar spine fusion surgery is traditionally performed with rigid fixation. Because the rigidity is often supraphysiologic, semirigid rods were developed. To the best of our knowledge, a comprehensive evaluation of rod material type on surgical outcomes has yet to be conducted. METHODS: A systematic review based on PRISMA guidelines was conducted across 3 electronic databases. After examination for inclusion and exclusion criteria, data were extracted from the studies. RESULTS: Seventeen studies, including 1399 patients, were included in this review. The mean rigid rod fusion rate is 92.2% and 95.5% for semirigid rods (P = 0.129). The mean improvement in back pain was 60.6% in rigid rods and 71.6% in semirigid rods. The improvement in leg pain was 81.9% and 77.2%, respectively. There were no differences in visual analog scale back pain score (P = 0.098), visual analog scale leg pain score (P = 0.136), or in functional improvement between rigid and semirigid rods (P = 0.143). There was no difference (P = 0.209) in the reoperation rate between rigid rods (13.1%) and semirigid rods (6.5%). There was a comparable incidence of adjacent segment disease (3%), screw fracture (1.7%), and wound infection (1.9%) between rod material types. CONCLUSIONS: There is a moderate level of evidence supporting that surgical intervention results in high fusion rates regardless of rod material type. Surgical intervention improves back pain, leg pain, and function, with neither material type showing clear superiority. There are comparable rates of reoperation, development of adjacent segment disease, development of mechanical complications, and incidence of infection in both rigid and semirigid rods. Further studies regarding rod material type are warranted.