Cervical orthosis does not improve postoperative pain following posterior cervical fusion: a randomized controlled trial.

PURPOSE: To determine whether postoperative neck pain in the first 4 weeks following multi-level posterior cervical fusion (PCF) with orthosis is equivalent to multi-level PCF without orthosis. METHODS: Patients were randomly assigned in a 1:1 ratio to postoperative orthosis (CO) for 6 weeks or no orthosis (NO). Randomization was stratified by indication (traumatic vs. degenerative), and preoperative opioid use. A model of longitudinal regression for repeated measures was used. The two-sided 95% confidence interval (CI) was used to test equivalence. If the CI lay between the pre-determined margin of equivalence (-2.0 to + 2.0 pain score) the two groups were considered equivalent. A multiple imputation procedure was used to replace missing data. RESULTS: Thirty-one patients were enrolled in each group. At baseline, the CO group had more neck pain (5.3 vs. 3.2, p = 0.013). The Four week post-operative neck pain intensity score was 4.6 ± 0.3 for the CO group vs. 4.9 ± 0.3 for the NO group. The 95% confidence interval (-1.2 to 0.6) was within the pre-determined equivalence margin. Neck Disability Index, quality-of-life scores, and arm pain were similar. Eleven patients in the CO group and 12 patients in the NO group had an adverse event. The CO group had reduced range of motion at 6 weeks. CONCLUSION: Pain scores over the first 4 weeks after surgery were equivalent for patients undergoing multi-level PCF treated with or without a cervical orthosis. Our findings do not support the routine use of a postoperative cervical orthosis for postoperative pain control. Clinical Trials Registration Number NCT04308122, April 22, 2020.

Surgery versus Conservative Care for Persistent Sciatica Lasting 4 to 12 Months.

BACKGROUND: The treatment of chronic sciatica caused by herniation of a lumbar disk has not been well studied in comparison with acute disk herniation. Data are needed on whether diskectomy or a conservative approach is better for sciatica that has persisted for several months. METHODS: In a single-center trial, we randomly assigned patients with sciatica that had lasted for 4 to 12 months and lumbar disk herniation at the L4-L5 or L5-S1 level in a 1:1 ratio to undergo microdiskectomy or to receive 6 months of standardized nonoperative care followed by surgery if needed. Surgery was performed by spine surgeons who used conventional microdiskectomy techniques. The primary outcome was the intensity of leg pain on a visual analogue scale (ranging from 0 to 10, with higher scores indicating more severe pain) at 6 months after enrollment. Secondary outcomes were the score on the Oswestry Disability Index, back and leg pain, and quality-of-life scores at 6 weeks, 3 months, 6 months, and 1 year. RESULTS: From 2010 through 2016, a total of 790 patients were screened; of those patients, 128 were enrolled, with 64 in each group. Among the patients assigned to undergo surgery, the median time from randomization to surgery was 3.1 weeks; of the 64 patients in the nonsurgical group, 22 (34%) crossed over to undergo surgery at a median of 11 months after enrollment. At baseline, the mean score for leg-pain intensity was 7.7 in the surgical group and 8.0 in the nonsurgical group. The primary outcome of the leg-pain intensity score at 6 months was 2.8 in the surgical group and 5.2 in the nonsurgical group (adjusted mean difference, 2.4; 95% confidence interval, 1.4 to 3.4; P<0.001). Secondary outcomes including the score on the Owestry Disability Index and pain at 12 months were in the same direction as the primary outcome. Nine patients had adverse events associated with surgery, and one patient underwent repeat surgery for recurrent disk herniation. CONCLUSIONS: In this single-center trial involving patients with sciatica lasting more than 4 months and caused by lumbar disk herniation, microdiskectomy was superior to nonsurgical care with respect to pain intensity at 6 months of follow-up. (Funded by Physicians' Services Incorporated Foundation; ClinicalTrials.gov number, NCT01335646.).

Microdiscectomy Is More Cost-effective Than a 6-Month Nonsurgical Care Regimen for Chronic Radiculopathy.

BACKGROUND: A recent randomized controlled trial (RCT), performed by the authors, comparing early surgical microdiscectomy with 6 months of nonoperative care for chronic lumbar radiculopathy showed that early surgery resulted in improved outcomes. However, estimates of the incremental cost-utility ratio (ICUR), which is often expressed as the cost of gaining one quality-adjusted life year (QALY), of microdiscectomy versus nonsurgical management have varied. Radiculopathy lasting more than 4 months is less likely to improve without surgical intervention and may have a more favorable ICUR than previously reported for acute radiculopathy. QUESTION/PURPOSE: In the setting of chronic radiculopathy caused by lumbar disc herniation, defined as symptoms and/or signs of 4 to 12 months duration, is surgical management more cost-effective than 6 months of nonoperative care from the third-party payer perspective based on a willingness to pay of less than CAD 50,000/QALY? METHODS: A decision analysis model served as the vehicle for the cost-utility analysis. A decision tree was parameterized using data from our single-center RCT that was augmented with institutional microcost data from the Ontario Case Costing Initiative. Bottom-up case costing methodology generates more accurate cost estimates, although institutional costs are known to vary. There were no major surgical cost drivers such as implants or bone graft substitutes, and therefore, the jurisdictional variance would be minimal for tertiary care centers. QALYs derived from the EuroQoL-5D were the health outcome and were derived exclusively from the RCT data, given the paucity of studies evaluating the surgical treatment of lumbar radiculopathy lasting 4 to 12 months. Cost-effectiveness was assessed using the ICUR and a threshold of willingness to pay CAD 50,000 (USD 41,220) per QALY in the base case. Sensitivity analyses were performed to account for the uncertainties within the estimate of cost utility, using both a probabilistic sensitivity analysis and two one-way sensitivity analyses with varying crossover rates after the 6-month nonsurgical treatment had concluded. RESULTS: Early surgical treatment of patients with chronic lumbar radiculopathy (defined as symptoms of 4 to 12 months duration) was cost-effective, in that the cost of one QALY was lower than the CAD 50,000 threshold (note: the purchasing power parity conversion factor between the Canadian dollar (CAD) and the US dollar (USD) for 2019 was 1 USD = 1.213 CAD; therefore, our threshold was USD 41,220). Patients in the early surgical treatment group had higher expected costs (CAD 4118 [95% CI 3429 to 4867]) than those with nonsurgical treatment (CAD 2377 [95% CI 1622 to 3518]), but they had better expected health outcomes (1.48 QALYs [95% CI 1.39 to 1.57] versus 1.30 [95% CI 1.22 to 1.37]). The ICUR was CAD 5822 per QALY gained (95% CI 3029 to 30,461). The 2-year probabilistic sensitivity analysis demonstrated that the likelihood that early surgical treatment was cost-effective was 0.99 at the willingness-to-pay threshold, as did the one-way sensitivity analyses. CONCLUSION: Early surgery is cost-effective compared with nonoperative care in patients who have had chronic sciatica for 4 to 12 months. Decision-makers should ensure adequate funding to allow timely access to surgical care given that it is highly likely that early surgical intervention is potentially cost-effective in single-payer systems. Future work should focus on both the clinical effectiveness of the treatment of chronic radiculopathy and the costs of these treatments from a societal perspective to account for occupational absences and lost patient productivity. Parallel cost-utility analyses are critical so that appropriate decisions about resource allocation can be made. LEVEL OF EVIDENCE: Level III, economic and decision analysis.

Charcot spinal arthropathy in patients with congenital insensitivity to pain: a report of two cases and review of the literature.

Charcot spine, or neuropathic spinal arthropathy, involves the progressive destruction of the spinal joint due to the lack of normal protective sensations and proprioception. A rare cause of Charcot spine is congenital insensitivity to pain, which is an absent or abnormal response to painful stimuli. There are few case reports describing this condition, and long-term follow-up data are limited. The presentation and treatment of two patients with Charcot spine secondary to congenital insensitivity to pain are described. Both cases were characterized by lumbar involvement and were treated with circumferential decompression and an extended lumbo-pelvic fusion construct. The cases described here demonstrate stable neurological status at 1.5 and 5 years follow-up. Patient characteristics, pre- and post-operative imaging, operative approach, and outcomes are described. The literature regarding this rare condition is also reviewed, with an emphasis on operative management and outcomes. Surgical management is traditionally complicated by a high rate of hardware failure and adjacent segment degeneration. The current review highlights the importance of prompt and aggressive management following diagnosis of Charcot spine, as well as extended follow-up.

Intradural Extramedullary Spinal Cord Metastasis of the Prostate: A Case Presentation and Review of the Literature.

Prostate cancer is associated with vertebral metastasis in up to 10% of patients; however, intradural spinal cord metastases (ISCM) are much less frequent. We present the clinical and histopathological findings of a patient with ISCM arising from prostate. A PubMed literature search for ISCM from the prostate yielded a total of nine additional cases. ISCM of the prostate occurs at a late stage of systemic disease and the prognosis is generally poor. Decompressive surgery followed by adjuvant radiation therapy may help reduce intractable pain and stabilize neurological symptoms, thereby improving quality of life.

Characterizing mJOA-defined post-surgical recovery patterns in patients with degenerative cervical myelopathy.

Background: Degenerative cervical myelopathy is a spinal disorder resulting in progressive cord compression and neurological deficits that are assessed using the modified Japanese Orthopedic Association (mJOA) questionnaire. It is difficult to predict which patients will recover neurological function after surgery, making it challenging for clinicians to set postoperative patient expectations. In this study, we used mJOA subscores to identify patterns of recovery and recovery timelines in patients with moderate and severe myelopathy. Methods: Fifty-three myelopathy patients were enrolled and completed the mJOA questionnaire both pre-surgery, and six weeks and six months post-surgery. Pearson chi-square tests were performed to assess relationships of both recovery patterns and recovery timelines with severity of disease. Results: Moderate myelopathy patients were significantly more likely than severe myelopathy patients to experience full recovery of upper extremity, lower extremity, and sensory domains. Disease severity did not significantly impact the timeline during which recovery occurs. Overall, >90% of patients experienced at least partial recovery by six months post surgery, 80% of which demonstrated it within the first six weeks. Conclusions: This study shows the more severe the disease experienced by myelopathy patients, the more likely they will be left with permanent disabilities despite surgery. Early identification and treatment are therefore necessary to prevent worsening quality of life and increased costs of functional dependence. The recovery timelines for each subscore are similar and provide new values to guide patient expectations in their potential post-operative recovery. The overall recovery timeline is more generalizable though potentially lacking the specificity patients seek.

L3-L4 Hyperlordosis and Decreased Lower Lumbar Lordosis Following Short-Segment L4-L5 Lumbar Fusion Surgery is Associated With L3-L4 Revision Surgery for Adjacent Segment Stenosis.

STUDY DESIGN: Retrospective review of prospective cohort. OBJECTIVES: Reoperation at L3-L4 for adjacent segment disease (ASD) is common after L4-L5 spine fusion. L4-S1 lower lumbar lordosis (LLL) accounts for the majority of global lumbar lordosis (GLL) and is modifiable during surgery. We sought to determine if a reduction in LLL leads to an increase in L3-L4 focal lumbar lordosis (L3-L4 FLL) and resulting risk of ASD at L3-L4. METHODS: We reviewed the records of a prospective cohort with lumbar spinal stenosis who underwent L4-L5 or L4-L5-S1 fusion between 2006 and 2012. Radiographic parameters-GLL, LLL, L3-L4 FLL, upper lumbar lordosis, lordosis distribution index, pelvic tilt, and pelvic incidence-were extracted from preoperative and postoperative lumbar spine radiographs. Statistical comparisons were made between those who underwent revision for post-fusion adjacent level stenosis at L3-L4 (REVISION) and those who did not (NO REVISION). RESULTS: Inclusion criteria were met by 104 patients. The REVISION cohort included 19 individuals. No significant differences in baseline demographics or operative details for the index procedure were found between groups. Postoperatively, when compared to the NO REVISION cohort, the REVISION cohort had a decrease in LLL (-2.6° vs + 1.5°, P = .011) and LDI (-5.1% vs + 1.3%, P = .039), and an increase in L3-L4 FLL (+2.6° vs -.6°, P = .001). CONCLUSIONS: A reduction in LLL and compensatory increase in L3-L4 FLL after initial lower lumbar fusion surgery resulted in more reoperation at L3-L4 for post-fusion adjacent level spinal stenosis.

A Cancer Care Ontario Consensus-Based Organizational Guideline for the Planning and Delivery of Spine Stereotactic Body Radiation Therapy Treatment in Ontario.

The proposed recommendations are primarily based on the consensus opinion and in-field experience of the Ontario Health/Cancer Care Ontario stereotactic body radiation therapy (SBRT) for Spine Metastasis Guideline Development Group and published literature when available. Primary consideration was given to the perceived benefits for patients and the small likelihood of harm arising from recommendation implementation. Apart from the magnetic resonance imaging (MRI) follow-up strategy, all evidence was considered indirect and was provided by the working group in conjunction with their collective expertise in the field of SBRT. The application of an SBRT program requires a multidisciplinary team consisting of a radiation oncologist, spine surgeon, neuroradiologist, medical physicist, medical dosimetrist, and radiation therapist. In Canada, linear accelerators are the most used treatment delivery units and should follow technology-specific quality assurance procedures. Immobilization technique is location dependant. Treatment planning MRI sequences should be acquired no more than 14 days from the date of treatment. In the case of epidural disease, simulation MRI should be completed no more than 7 days from the date of treatment. After treatment, patients should be followed with routine clinical visits every 3 months for the first year, every 3 to 6 months during years 2 and 3, and every 4 to 6 months thereafter. The recommendations enclosed provide a framework for the minimum requirements for a cancer center in Ontario, Canada to offer SBRT for spine metastases.

Sagittal alignment in operative degenerative lumbar spondylolisthesis: a scoping review.

Background: The benefit of surgical intervention over conservative treatment for degenerative lumbar spondylolisthesis (DLS) patients with neurologic symptoms is well-established. However, it is currently unclear what breadth of available evidence exists on regional and global sagittal alignment in DLS surgery. As such, the purpose of the current study is to conduct a scoping review to map and synthesize the DLS literature regarding the current radiographic assessment of sagittal spinal alignment in DLS surgery. Methods: A comprehensive search of the MEDLINE, EMBASE and Cochrane databases from January 1971 to January 2023 was performed for all DLS studies examining sagittal spinal alignment parameters with DLS surgery according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Review (PRISMA-ScR) protocol. Results: From 2,222 studies, a total of 109 studies were included, representing 10,730 patients with an average age of 63.0 years old and average follow-up of 35.1 months postoperatively. Among included studies, 93 (85%), were largely published in the last decade and predominantly represented retrospective cohorts 70 (64%) or case series 22 (20%). A common theme among the reporting of radiographic parameters in the included investigations was the assessment of the magnitude and/or maintenance of a radiographic change postoperatively, with 92 (84%) studies reporting these findings. The majority of studies focused on index DLS level [33 (30%) studies] or lumbar spine radiographic imaging [33 (30%) studies] only. Thirty-seven (34%) studies reported spinopelvic parameters, with only 13 (12%) of included studies assessing 36-inch standing lateral radiographs and overall alignment. Conclusions: There is increasing prevalence of investigations assessing sagittal spinal alignment parameters in DLS surgery. Although, there is an increasing prevalence of studies investigating sagittal spinal alignment parameters in DLS surgery the quality of the currently available literature on this topic is of overall low evidence and largely retrospective in nature. Additionally, there is limited analysis of global sagittal spinal alignment in DLS suggesting that future investigational emphasis should prioritize longitudinally followed large prospective cohorts or multi-centre randomized controlled trials. Attempts at standardizing the radiographic and functional outcome reporting techniques across multi-centre investigations and prospective cohorts will allow for more robust, reproducible analyses of significance to be conducted on DLS patients.

"Winged" Eagle's syndrome: neurophysiological findings in a rare cause of spinal accessory nerve palsy. Illustrative cases.

BACKGROUND: Eagle's syndrome (ES) classically describes dysphagia, globus sensation, and otalgia from an elongated and calcified styloid process or stylohyoid ligament. Compression of the spinal accessory nerve (SAN) has not been reported as an associated feature of ES or related variants. OBSERVATIONS: The authors describe two cases of an atypical "winged" variant with SAN palsy resulting from compression by a posteriorly angulated or calcified styloid process. Both patients exhibited lateral scapular winging and atrophy of the trapezius and sternocleidomastoid muscles. Electrophysiological studies demonstrated motor unit preservation; therefore, surgical exploration, styloidectomy, and SAN decompression were performed through a transcervical approach. Postoperatively, both patients had improvements in pain and shoulder mobility, the return of muscle strength, and electrophysiological evidence of trapezius reinnervation. LESSONS: Compression of the SAN, which can be identified both clinically and on electrodiagnostic testing, is an atypical finding that can result from a posteriorly angulated or calcified styloid process. This winged variant of ES should be included in the differential for SAN palsy, and a multidisciplinary approach is recommended for assessment and management.

Functional outcomes correlate with sagittal spinal balance in degenerative lumbar spondylolisthesis surgery.

BACKGROUND CONTEXT: Degenerative lumbar spondylolisthesis (DLS) is a debilitating condition associated with poor preoperative functional status. Surgical intervention has been shown to improve functional outcomes in this population though the optimal surgical procedure remains controversial. The importance of maintaining and/or improving sagittal and pelvic spinal balance parameters has received increasing interest in the recent DLS literature. However, little is known about the radiographic parameters most associated with improved functional outcomes among patients undergoing surgery for DLS. PURPOSE: To identify the effect of postoperative sagittal spinal alignment on functional outcome after DLS surgery. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Two-hundred forty-three patients in the Canadian Spine Outcomes and Research Network (CSORN) prospective DLS study database. OUTCOME MEASURES: Baseline and 1-year postoperative leg and back pain on the 10-point Numeric Rating Scale and baseline and 1-year postoperative disability on the Oswestry Disability Index (ODI). METHODS: All enrolled study patients had a DLS diagnosis and underwent decompression in isolation or with posterolateral or interbody fusion. Global and regional radiographic alignment parameters were measured at baseline and 1-year postoperatively including sagittal vertical axis (SVA), pelvic incidence and lumbar lordosis (LL). Both univariate and multiple linear regression was used to assess for the association between radiographic parameters and patient-reported functional outcomes with adjustment for possible confounding baseline patient factors. RESULTS: Two-hundred forty-three patients were available for analysis. Among participants, the mean age was 66 with 63% (153/243) female with the primary surgical indication of neurogenic claudication in 197/243 (81%) of patients. Worse pelvic incidence-LL mismatch was correlated with more severe disability [ODI, 0.134, p<.05), worse leg pain (0.143, p<.05) and worse back pain (0.189, p<.001) 1-year postoperatively. These associations were maintained after adjusting for age, BMI, gender, and preoperative presence of depression (ODI, R2 0.179, ß, 0.25, 95% CI 0.08, 0.42, p=.004; back pain R2 0.152 (ß, 0.05, 95% CI 0.022, 0.07, p<.001; leg pain score R2 0.059, ß, 0.04, 95% CI 0.008, 0.07, p=.014). Likewise, reduction of LL was associated with worse disability (ODI, R2 0.168, ß, 0.04, 95% CI -0.39, -0.02, p=.027) and worse back pain (R2 0.135, ß, -0.04, 95% CI -0.06, -0.01, p=.007). Worsened SVA correlated with worse patient reported functional outcomes (ODI, R2 0.236, ß, 0.12, 95% CI 0.05, 0.20, p=.001). Similarly, an increase (worsening) in SVA resulted in a worse NRS back pain (R2 0.136, ß, 0.01, 95% CI .001, 0.02, p=.029) and worse NRS leg pain (R2 0.065, ß, 0.02, 95% CI 0.002, 0.02, p=.018) scores regardless of surgery type. CONCLUSIONS: Preoperative emphasis on regional and global spinal alignment parameters should be considered in order to optimize functional outcome in lumbar degenerative spondylolisthesis treatment.

Early Versus Delayed Microdiscectomy for Chronic Sciatica Lasting 4-12 Months Secondary to Lumbar Disc Herniation: A Secondary Analysis of a Randomized Controlled Trial.

OBJECTIVES: To compare the effect of delaying surgery on clinical outcome in patients with chronic sciatica secondary to lumbar disc herniation. METHODS: Patients with sciatica lasting 4-12 months and lumbar disc herniation at the L4-L5 or L5-S1 level were randomized to undergo microdiscectomy (early surgery) or to receive 6 months of nonoperative treatment followed by surgery if needed (delayed surgery). Outcomes were leg pain, Oswestry Disability Index score (ODI), back pain, SF-36 physical component (PCS) and mental component (MCS) summary scores, employment, and satisfaction measured preoperatively and at 6 weeks, 3 months, 6 months, and 1 year after surgery. RESULTS: Of the 64 patients in the early surgery group, 56 underwent microdiscectomy an average of 3 ± 2 weeks after enrollment. Of the 64 patients randomized to nonoperative care, 22 patients underwent delayed surgery an average of 53 ± 24 weeks after enrollment. The early surgery group experienced less leg pain than the delayed surgery group, which was the primary outcome, at 6 months after surgery (early surgery 2.8 ± .4 vs delayed surgery 4.8 ± .7; difference, 2.0; 95% confidence interval, .5-3.5). The overall estimated mean difference between groups significantly favored early surgery for leg pain, ODI, SF36-PCS, and back pain. The adverse event rate was similar between groups. CONCLUSIONS: Patients presenting with chronic sciatica treated with delayed surgery after prolonging standardized non-operative care have inferior outcomes compared to those that undergo expedited surgery.

Evaluation of the contact surface between vertebral endplate and 3D printed patient-specific cage vs commercial cage.

Biomechanical study. To evaluate the performance of the contact surface for 3D printed patient-specific cages using CT-scan 3D endplate reconstructions in comparison to the contact surface of commercial cages. Previous strategies to improve the surface of contact between the device and the endplate have been employed to attenuate the risk of cage subsidence. Patient-specific cages have been used to help, but only finite-element studies have evaluated the effectiveness of this approach. There is a possible mismatch between the CT-scan endplate image used to generate the cage and the real bony endplate anatomy that could limit the performance of the cages. A cadaveric model is used to investigate the possible mismatch between 3D printed patient-specific cages and the endplate and compare them to commercially available cages (Medtronic Fuse and Capstone). Contact area and contact stress were used as outcomes. When PS cage was compared to the Capstone cage, the mean contact area obtained was 100 ± 23.6 mm2 and 57.5 ± 13.7 mm2, respectively (p < 0.001). When compared to the Fuse cage, the mean contact area was 104.8 ± 39.6 mm2 and 55.2 ± 35.1 mm2, respectively(p < 0.001). Patient-specific cages improve the contact area between the implant and the endplate surface, reducing the contact stress and the risk of implant subsidence during LIF surgeries.

Biomechanical Comparison of Subsidence Between Patient-Specific and Non-Patient-Specific Lumbar Interbody Fusion Cages.

STUDY DESIGN: Biomechanical study. OBJECTIVES: Several strategies to improve the surface of contact between an interbody device and the endplate have been employed to attenuate the risk of cage subsidence. 3D-printed patient-specific cages have been presented as a promising alternative to help mitigate that risk, but there is a lack of biomechanical evidence supporting their use. We aim to evaluate the biomechanical performance of 3D printed patient-specific lumbar interbody fusion cages in relation to commercial cages in preventing subsidence. METHODS: A cadaveric model is used to investigate the possible advantage of 3D printed patient-specific cages matching the endplate contour using CT-scan imaging in preventing subsidence in relation to commercially available cages (Medtronic Fuse and Capstone). Peak failure force and stiffness were analyzed outcomes for both comparison groups. RESULTS: PS cages resulted in significantly higher construct stiffness when compared to both commercial cages tested (>59%). PS cage peak failure force was 64% higher when compared to Fuse cage (P < .001) and 18% higher when compared to Capstone cage (P = .086). CONCLUSIONS: Patient-specific cages required higher compression forces to produce failure and increased the cage-endplate construct' stiffness, decreasing subsidence risk.

Preoperative Disc Angle is an Important Predictor of Segmental Lordosis After Degenerative Spondylolisthesis Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: To determine the effect of interbody cages inserted via posterior approach on segmental lordosis in the setting of preoperative lordotic vs kyphotic discs in patients with lumbar degenerative spondylolisthesis (LDS). METHODS: Retrospective analysis of prospectively collected data on assessment and management of LDS patients from 2 contributing centres. Patients were analyzed preoperatively and at 12-month follow-up with standing lumbar radiographs. Index level segmental lumbar lordosis (SLL), disc angle and global lumbar lordosis was measured. Patients were stratified into 4 groups based on index level disc angle and procedure: preoperative lordotic posterolateral fusion (group L-PLF); preoperative kyphotic PLF (group K-PLF); preoperative lordotic interbody fusion (IF) (group L-IF); preoperative kyphotic IF (group K-IF). RESULTS: A total of 100/111 (90%) patients completed follow-up with 40 in group L-IF and 48 in group K-IF. There were 18 patients in group L-PLF and 5 in group K-PLF. Among patients with preoperatively lordotic disc angles who had a worsening of SLL, group L-IF had worse SLL than group L-PLF patients, with differences persisting at one-year (mean difference 2.30, 95% CI, .3, 4.3, P = .029). Patients in group K-IF achieved improvement in SLL at one-year more frequently than group L-IF (67% vs 44%, P = .046), with similar mean improvement magnitude between groups L-IF and K-IF (-1.1, 95% CI, -3.7, 1.6, P = .415). CONCLUSION: Segmental lordosis worsening was greater with preoperative index lordotic disc angles when an interbody cage was used. Patients who have a kyphotic disc preoperatively gain more lordosis with interbody cage use.

The Impact of Surgical Site Infection on Patient Outcomes After Open Posterior Instrumented Thoracolumbar Surgery for Degenerative Disorders.

BACKGROUND: Few reports in the literature have described the long-term outcome of postoperative infection from the patient perspective. The aim of the present study was to determine if complicated surgical site infection (SSI) affects functional recovery and surgical outcomes up to 2 years after posterior instrumented thoracolumbar surgery for the treatment of degenerative disorders. METHODS: This retrospective cohort study involved patients who had been enrolled in a previous randomized controlled trial that examined antibiotic use for open posterior multilevel thoracolumbar or lumbar instrumented fusion procedures. In the present study, patients who had SSI (n = 79) were compared with those who did not (n = 456). Patient-reported outcome measures (PROMs) included the Oswestry Disability Index (ODI), leg and back pain scores on a numeric rating scale, Short Form-12 (SF-12) summary scores, and satisfaction with treatment at 1.5, 3, 6, 12, and 24 months. Surgical outcomes included adverse events, readmissions, and additional surgery. RESULTS: The median time to infection was 15 days. Of the 535 patients, 31 (5.8%) had complicated infections and 48 (9.0%) had superficial infections. Patients with an infection had a higher body mass index (BMI) (p = 0.001), had more commonly received preoperative vancomycin (p = 0.050), were more likely to have had a revision as the index procedure (p = 0.004), had worse preoperative mental functioning (mental component summary score, 40.7 ± 1.6 versus 44.1 ± 0.6), had more operatively treated levels (p = 0.024), and had a higher rate of additional surgery (p = 0.001). At 6 months after surgery, patients who developed an infection scored worse on the ODI by 5.3 points (95% confidence interval [CI], 0.4 to 10.1 points) and had worse physical functioning by -4.0 points (95% CI, -6.8 to -1.2 points). Comparison between the groups at 1 and 2 years showed no difference in functional outcomes, satisfaction with treatment, or the likelihood of achieving the minimum clinically important difference (MCID) for the ODI. CONCLUSIONS: SSI more than doubled the post-discharge emergency room visit and additional surgery rates. Patients with SSI initially (6 months) had poorer overall physical function representing the delay to recovery; however, the negative impact resolved by the first postoperative year. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Geometric and Volumetric Relationship Between Human Lumbar Vertebra and CT-based Models.

RATIONALE AND OBJECTIVES: Crucial to the process of three-dimensional (3D) printing is the knowledge of how the actual structure or organ relates dimensionally to its corresponding medical image. This study will examine the differences between human lumbar vertebrae, 3D scans of these bones, 3D models based on computed tomographic (CT) scans, and 3D-printed models. MATERIALS AND METHODS: CT scans were obtained for six human lumbar spines. The bones were cleaned, and 3D scanned. 3D mesh models were created from the CT data, and then 3D printed. Four models were analyzed: anatomic bones, 3D-scanned models, CT-models, and 3D-printed models. Manual measurements were performed for all model types, and segmentation metric comparisons were performed comparing the 3D-scanned models to the CT-models. RESULTS: There was no statistical difference between manual measurements when comparing each parameter of all model types, except for vertebral width (p = 0.044). There was no statistical difference when comparing the average of all measurements between all model types (p = 0.247). The mean Hausdorff distance was 0.99 mm (SD 0.55 mm) when comparing 3D-scanned model to CT-model. The mean Dice coefficient was 0.90 (SD 0.07) when comparing 3D-scanned model to CT-model. The mean volume for 3D-scanned model and CT-model were 41.6 ml and 45.9 ml (p < 0.001), respectively. CONCLUSION: This study clarifies the geometric and volumetric relationship between human lumbar vertebra and CT-based vertebral models. Segmentation metrics reveal a 1 mm difference between examined bones (using the 3D-scanned bone as a surrogate), and the CT measurements. This is confirmed by a volumetric difference of 4.3 ml, between the larger CT-based model and the smaller bone.

Cranial nerve and intramedullary spinal malignant peripheral nerve sheath tumor associated with neurofibromatosis-1.

Background: Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon but aggressive neoplasms associated with radiation exposure and neurofibromatosis Type I (NF1). Their incidence is low compared to other nervous system cancers, and intramedullary spinal lesions are exceedingly rare. Only a few case reports have described intramedullary spinal cord MPNST. Case Description: We describe the clinical findings, management, and outcome of a young patient with NF1 who developed aggressive cranial nerve and spinal MPNST tumors. This 35-year-old patient had familial NF1 and a history of optic glioma treated with radiation therapy (RT). She developed a trigeminal MPNST that was resected and treated with RT. Four years later, she developed bilateral lower extremity deficits related to an intramedullary cervical spine tumor, treated surgically, and found to be a second MPNST. Conclusion: To the best of our knowledge, this is the first report of cranial nerve and intramedullary spinal MPNSTs manifesting in a single patient, and only the third report of a confined intramedullary spinal MPNST. This unusual case is discussed in the context of a contemporary literature review.

The Development of Novel 2-in-1 Patient-Specific, 3D-Printed Laminectomy Guides with Integrated Pedicle Screw Drill Guides.

OBJECTIVE: To determine if 2-in-1 patient-specific laminectomy and drill guides can be safely used to perform laminectomy and pedicle screw insertion. METHODS: This was a cadaveric study designed to test novel 2-in-1 patient-specific laminectomy guides, with modular removable pedicle screw drill guides. Three-dimensional (3D) printing has not been applied to laminectomy. This cadaveric study tests novel 2-in-1 patient-specific laminectomy guides, with modular removable pedicle screw drill guides. Computed tomography (CT) scans of 3 lumbar spines were imported into 3D Slicer. Spinal models and patient-specific guides were created and 3D printed. The bones were cleaned to visualize and record the under surface of the lamina during laminectomy. Pedicle screws and laminectomies were performed with the aid of patient-specific guides. CT scans were performed to compare planned and actual screw and laminectomy positions. RESULTS: Thirty screws were inserted in 15 lumbar vertebrae by using the integrated 2-in-1 patient-specific drill guides. There were no cortical breaches on direct examination, or on postoperative CT. Digital video analysis revealed the burr tip did not pass deep to the inner table margin of the lamina in any of the 30 laminectomy cuts. Average surgical time was 4 minutes and 46 seconds (standard deviation, 1 min 38 sec). CONCLUSIONS: This study has explored the development of novel 2-in-1 patient-specific, 3D-printed laminectomy guides with integrated pedicle screw drill guides, which are accurate and safe in the laboratory setting. These instruments have the potential to simplify complex surgical steps, and improve accuracy, time, and cost.

Discectomy Compared with Standardized Nonoperative Care for Chronic Sciatica Due to a Lumbar Disc Herniation: A Secondary Analysis of a Randomized Controlled Trial with 2-Year Follow-up.

BACKGROUND: Randomized controlled trials evaluating acute sciatica have not demonstrated prolonged improvements in terms of patient-reported pain and function. For chronic sciatica, however, microdiscectomy has been found to be superior at 1 year. Whether this effect persists during the second year is not known. The purpose of the present study was to report the 2-year outcomes following lumbar microdiscectomy as compared with standardized nonoperative care for the treatment of chronic sciatica resulting from a lumbar disc herniation. METHODS: The present study is a secondary analysis of a previously reported randomized controlled trial with extension to 2 years of follow-up. Patients with radiculopathy for 4 to 12 months resulting from an L4-L5 or L5-S1 disc herniation were randomized to microdiscectomy or 6 months of nonoperative care followed by surgery if needed. Intention-to-treat analysis was performed at 2 years for the primary outcome (the intensity of leg pain) (range of possible scores, 0 [no pain] to 10 [worst pain]) as well as for secondary outcomes (including the Oswestry Disability Index score, the intensity of back pain, and quality of life). RESULTS: One hundred and twenty-eight patients were randomized in the present study. Twenty-four (38%) of the 64 patients who had been randomized to nonoperative care crossed over to surgical treatment by 2 years following enrollment. At the 2-year time point, the follow-up rate was approximately 70%. At 2 years, the operative group had less leg pain than the nonoperative group (mean, 2.8 ± 0.4 compared with 4.2 ± 0.4; treatment effect, 1.3 [95% confidence interval, 0.3 to 2.4]). The treatment effect favored surgery for all secondary outcome measures at 6 months and 1 year and for back pain intensity and physical function at 2 years. CONCLUSIONS: At 2 years, the present study showed that microdiscectomy was superior to nonoperative care for the treatment of chronic sciatica resulting from an L4-L5 or L5-S1 disc herniation. However, the difference between the groups did not surpass the minimal clinically important difference at 2 years as was reached at earlier follow-up points, likely as the result of patients crossing over from nonoperative to operative treatment. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.