Staged circumferential lumbar fusions have less intraoperative complications and shorter operative time with no difference in 30-, 90-, and 1-year complications: a propensity-matched cohort analysis of 190 patients.

BACKGROUND CONTEXT: Circumferential lumbar fusions (cLFs) are becoming more common with increasing and more minimally invasive anterior access techniques. Staging allows reassessment of indirect decompression and alignment prior to the posterior approach, and optimization of OR time management. Safety of staging has been well documented in deformity surgery but has yet to be delineated in less extensive, degenerative cLFs. PURPOSE: The purpose of this study is to compare perioperative complications and outcomes between staged versus single-anesthetic circumferential fusions in the lumbar spine. STUDY DESIGN: Propensity-matched comparative observational cohort. PATIENT SAMPLE: Patients who underwent cLFs for lumbar degenerative disease. OUTCOME MEASURES: In-hospital, 30-day, 90-day, and 1-year complications. METHODS: From 123 patients undergoing single-anesthetic and 154 patients undergoing staged cLF, 95 patients in each group were propensity-matched based on age, sex, BMI, ASA score, smoking, revision, and number of levels. We compared perioperative, 30-day, 90-day, and 1-year complications between the two cohorts. RESULTS: Mean days between stages was 1.58. Single-anesthetic cLF had longer total surgery time (304 vs 240 minutes, p<.001) but shorter total PACU total time (133 vs 196 minutes, p<.001). However, there was no difference in total anesthesia time (368 vs 374 minutes, p=.661) and total EBL (357 vs 320cc, p=.313). Intraoperative complications were nine incidental durotomies in the single-anesthetic and one iliac vein injury in the staged group (9% vs 1%, p=.018). There was no difference of in-hospital (38 vs 31, p=.291), 30-day (16 vs 23, p=.281), 90-day (10 vs 15, p=.391), 1-year complications (9 vs 12, p=.644), and overall cumulative 1-year complications (54 vs 56, p=.883) between the two cohorts. CONCLUSIONS: There is a decrease in total surgical time and intraoperative complications during staged compared with single-anesthetic cLF with no difference in in-hospital, 30-day, 90-day, and 1-year complications between approaches.

Normative Bone Mineral Density Measured on Computed Tomography Scans in Children and Adolescents.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To provide reference values for Hounsfield unit (HU) measured on computed tomography (CT) scans of children and adolescents. SUMMARY OF BACKGROUND DATA: Spine surgeons increasingly use HU on spine CT as a measure of bone mineral density (BMD). This has not been described in children and adolescents. PATIENTS AND METHODS: Pediatric patients who had a spine CT between 2012 and 2022 were identified. Patients who had more than 1 comorbidity or were syndromic were excluded. Using the bone window, 3 axial images (cephalad, middle, and caudal) of each vertebra were selected. In each axial view, the HU was measured using a "region of interest" (ROI) that included the total cancellous bone area and an ROI excluding the radiolucency present in the posterior vertebral body ("total" vs . "limited"). HU values were compared between total and limited areas and between the axial images at the cephalad, middle, and caudal levels. Each age category data were estimated and stratified. RESULTS: A total of 144 patients (79 females and 65 males) from 2 to 17 years old were included. Mean limited HU was consistently lower than total HU across all images and lumbar levels except for L1. Limited HU taken mid-vertebral body was also consistently lower than those taken cephalad or caudad. Mean limited HU across all ages including all levels was 227 ± 50 (range: 109-357). Stratifying by age showed a gradual decrease in BMD from age 2 to 10 followed by an increase. CONCLUSIONS: This is the first study to measure HU on lumbar CTs in children and adolescents. The technique of measuring BMD in adults should be modified in children by using an ROI that excludes the rarefaction present in the posterior vertebral body. Further studies are needed to evaluate the age-dependent changes in BMD seen in this study.

Opioid-sparing Anesthesia Decreases In-hospital and 1-year Postoperative Opioid Consumption Compared With Traditional Anesthesia: A Propensity-matched Cohort Study.

STUDY DESIGN: Propensity-matched cohort. OBJECTIVE: The aim of this study was to determine if opioid-sparing anesthesia (OSA) reduces in-hospital and 1-year postoperative opioid consumption. SUMMARY OF BACKGROUND DATA: The recent opioid crisis highlights the need to reduce opioid exposure. We developed an OSA protocol for lumbar spinal fusion surgery to mitigate opioid exposure. MATERIALS AND METHODS: Patients undergoing lumbar fusion for degenerative conditions over one to four levels were identified. Patients taking opioids preoperatively were excluded. OSA patients were propensity-matched to non-OSA patients based on age, sex, smoking status, body mass index, American Society of Anesthesiologists grade, and revision versus primary procedure. Standard demographic and surgical data, daily in-hospital opioid consumption, and opioid prescriptions 1 year after surgery were compared. RESULTS: Of 296 OSA patients meeting inclusion criteria, 172 were propensity-matched to non-OSA patients. Demographics were similar between cohorts (OSA: 77 males, mean age=57.69 yr; non-OSA: 67 males, mean age=58.94 yr). OSA patients had lower blood loss (326 mL vs. 399 mL, P =0.014), surgical time (201 vs. 233 min, P <0.001) emergence to extubation time (9.1 vs. 14.2 min, P< 0.001), and recovery room time (119 vs. 140 min, P =0.0.012) compared with non-OSA patients. Fewer OSA patients required nonhome discharge (18 vs. 41, P =0.001) compared with the non-OSA cohort, but no difference in length of stay (90.3 vs. 98.5 h, P =0.204). Daily opioid consumption was lower in the OSA versus the non-OSA cohort from postoperative day 2 (223 vs. 185 morphine milligram equivalents, P =0.017) and maintained each day with lower total consumption (293 vs. 225 morphine milligram equivalents, P =0.003) throughout postoperative day 4. The number of patients with active opioid prescriptions at 1, 3, 6, and 12 months postoperative was statistically fewer in the OSA compared with the non-OSA patients. CONCLUSIONS: OSA for lumbar spinal fusion surgery decreases in-hospital and 1-year postoperative opioid consumption. The minimal use of opioids may also lead to shorter emergence to extubation times, shorter recovery room stays, and fewer discharges to nonhome facilities.

Comparison of Bone Mineral Density in Children and Adolescents on CT Versus DEXA Scan.

STUDY DESIGN: Retrospective cross-sectional. OBJECTIVES: To determine associations between Hounsfield Units (HU) within a Region of interest (ROI) on CT scans and Dual Energy X-ray Absorptiometry (DEXA) measurements in children and adolescents. SUMMARY OF BACKGROUND DATA: HU on CT scans as a proxy for bone mineral density (BMD) is widely used in adults. However, the utility of CT as a proxy for BMD have not been evaluated in children and adolescents. METHODS: Patients younger than 18 years with a lumbar spine CT scan and a DEXA within 6 months of each other were identified. A ROI was used to measure the HU at each lumbar vertebral body on mid-axial cuts. Charts were reviewed for demographics, medical co-morbidities and DEXA reports. Correlation coefficients were calculated between mean DEXA Z-score and HU value. Patients were also stratified by Z-score (≥ -1.0, between -1.0 and -2.0, and ≤-2.0) and matched by age and BMI to a cohort of healthy children and compared. RESULTS: A moderate correlation between mean DEXA Z-score and mean HU on CT was found (r2=0.42, P<0.001). After matching for age and BMI, 21 patients in each group between the age of 4 and 17 years were analyzed. The mean HU value of the control group was 231.69. When stratified by Z-score (≥ -1.0, between -1.0 and -2.0, and ≤-2.0), the mean HU values were 244.59, 216.50, and 176.54, respectively. Patients with a Z-score of ≤-2.0 had a significantly lower mean HU than age matched controls. CONCLUSIONS: HU on lumbar CT in children and adolescents with DEXA Z-scores less than -2.0, were lower when compared to healthy age and BMI matched controls. This study suggests that HU on opportunistic CT scans of the spine may be used as a reasonable proxy for BMD in the pediatric population.

Risk Factors of Screw Malposition in Robot-Assisted Cortical Bone Trajectory: Analysis of 1344 Consecutive Screws in 256 Patients.

STUDY DESIGN: Retrospective single-center study using prospectively collected data. OBJECTIVE: To describe the incidence of and identify risk factors for intraoperative screw malposition secondary to skive or shift during robot-assisted cortical bone trajectory (RA-CBT) insertion. SUMMARY OF BACKGROUND DATA: RA-CBT screw malposition occurs through two distinct modes, skive or shift. Skive occurs when a downward force applied to the cannula, drill, tap, or screw, causes the instrument to deflect relative to its bony landmark. Shift is a change in position of the robot-assisted system relative to the patient after registration. METHODS: A consecutive series of patients older than 18 years who underwent RA-CBT screw placement between January 2019 and July 2022 were enrolled. Baseline demographic and surgical data, Hounsfield Units (HU) at L1, and vertebral shape related to screw planning were collected. Skive or shift was recorded in the operating room on a data collection form. RESULTS: Of 1344 CBT screws in 256 patients, malposition was recognized intraoperatively in 33 screws (2.4%) in 27 patients (10.5%); 19 via skive in 17 and 14 via shift in 10 patients. These patients had higher BMI than patients without malposition (33.0 kg/m2 vs 30.5 kg/m2, P=0.037). Patients with skive had higher HU (178.2 vs 145.2, P=0.035), compared to patients with shift (139.2 vs 145.2, P=0.935) and patients without screw malposition. More than half of screw malposition was observed at the UIV. At the UIV, if the screw's overlap to the bone surface at the insertion point was decreased, skive was more likely (57% vs 87%, P<0.001). No patients were returned to the operating room for screw revision. CONCLUSIONS: Intraoperative screw malposition occurred in 2.4% of RA-CBT. High BMI was associated with screw malposition, regardless of etiology. Skive was associated with high HU and decreased screw overlap to bone surface at the insertion point.

Quantitative Romberg on a Force Plate: Objective Assessment Before and After Surgery for Cervical Spondylotic Myelopathy.

STUDY DESIGN: Longitudinal Observational Cohort. OBJECTIVES: The purpose of this study was to evaluate the utility of Quantitative Romberg measurements as pre- and post-op balance outcome measures. SUMMARY OF BACKGROUND DATA: Cervical Spondylotic Myelopathy (CSM) is characterized by balance deficiencies produced by impaired proprioception. Evaluation is subjective and binary physical exam findings lack the precision to assess postoperative outcome improvement. METHODS: CSM patients were prospectively enrolled to undergo pre- and postoperative Quantitative Romberg tests on a force plate to record center of pressure (COP) motion for 30 seconds with eyes open followed by eyes closed. Revision cases were excluded. Kinematics of COP movement parameters were compared between pre- and postoperative state for each patient. RESULTS: Twenty-seven CSM patients were enrolled and completed both pre/post testing. Mean age was 60.0 years with 13 (48%) males, 9 (33%) smokers. Mean number of surgical levels was 2.48. The minimum mean follow-up was six months. There was a statistically significant improvement in eyes closed after surgery compared to pre-operative for total COP motion (523.44 cm vs. 387.00 cm, P<0.001), average sway speed (17.41 cm/s vs. 13.00 cm/s, P<0.001) and total lateral COP motion (253.44 cm vs. 186.70 cm, P<0.001). There was no statistically significant improvement in mJOA (13.29 vs. 14.29, P=0.28). CONCLUSION: CSM balance findings on Quantitative Romberg testing significantly improves postoperatively in patients with CSM. These findings support this testing as representative of proprioceptive balance deficiencies seen in CSM. Quantitative Romberg may be used as an objective measure of clinical outcome and assist in stratification of surgical interventions, surgery timing and technique.

Comparison of revision surgery for pseudarthrosis with or without adjacent segment disease after anterior cervical discectomy and fusion.

Background: Patients with a pseudarthrosis after anterior cervical discectomy and fusion (ACDF) may have concurrent adjacent segment disease (ASD). Although prior studies have shown posterior cervical decompression and fusion (PCDF) is effective in repairing pseudarthrosis, improvement in patient reported outcomes (PROs) has been marginal. The aim of this study is to evaluate the effectiveness of PCDF in achieving symptom relief in patients with pseudarthrosis after ACDF and whether that is altered by the additional treatment of ASD. Methods: Thirty-two patients with pseudarthrosis were compared with 31 patients with pseudarthrosis and concurrent ASD after ACDF who underwent revision PCDF with a minimum 1-year follow-up. Primary outcomes measures included the neck disability index (NDI), and numerical rating scale (NRS) scores for neck and arm pain. Secondary measures included estimated blood loss (EBL), operating room (OR) time, and length of stay. Results: Demographics between cohorts were similar, however there was a significantly higher mean body mass index (BMI) in the group with concurrent ASD (32.23 vs. 27.76, p=.007). Patients with concurrent ASD had more levels fused during PCDF (3.7 vs. 1.9, p<.001), greater EBL (165 cc vs. 106 cc, p=.054), and longer OR time (256 minutes vs. 202 minutes, p<.000). Preoperative PROs for NDI (56.7 vs. 56.5, p=.954), NRS arm pain (5.9 vs. 5.7, p=.758), and NRS neck pain (6.6 vs. 6.8, p=.726) were similar in both cohorts. At 12 months patients with concurrent ASD experienced a slightly greater, but not statistically significant, improvement in PROs (Δ NDI 4.40 vs. -1.44, Δ NRS neck pain 1.17 vs. 0.42, Δ NRS arm pain 1.28 vs. 0.10, p=.107). Conclusions: PCDF is a standard procedure for treatment of pseudarthrosis following ACDF, however improvements in PROs are marginal. Slightly greater improvements were seen in patients whose indication for surgery also included concurrent ASD, rather than a diagnosis of pseudarthrosis alone.