Does hinge sidedness influence laterality of C5 palsy after expansile open-door cervical laminoplasty?

OBJECTIVE: Cervical expansile open-door laminoplasties (EOLPs) have an open side and a hinge side, with the open side being bridged by grafts or miniplates. The authors explored the possibility that the open-door side might have a greater incidence of C5 palsy due to a greater stretch of the ipsilateral C5 nerve root. METHODS: This study was a retrospective review of prospectively collected data over a period of 25 years specifically assessing surgical complications. Included were patients who underwent EOLP for myelopathy, radiculopathy, or mild central cord injuries (American Spinal Injury Association Impairment Scale [AIS] grade D). Exclusion criteria included preexisting C5 weakness; patients with AIS grade A, B, or C injury; and added instrumentation or additional surgical procedures. Patients were monitored postoperatively for C5 palsy or any other complications. A comparison group included patients who underwent cervical laminectomy and fusion (CLF). RESULTS: A total of 327 laminoplasties were collected, and 31 patients were excluded because of severe spinal cord injury (AIS grades A-C), 3 for preoperative C5 weakness, and 21 for instrumentation or additional surgical procedures. Thus, 272 patients were analyzed with a mean age of 59.9 years (range 22-88 years). Diagnoses at presentation were cervical myelopathy (84.1%), central cord syndrome (7.2%), cervical myeloradiculopathy (3.4%), ossification of the posterior longitudinal ligament (1.9%), and other (3.4%). The most common complications were C5 palsy (n = 7, 2.6%) and wound infection (n = 7, 2.6%). Of the 7 cases of postoperative C5 palsies in this study, 6 occurred on the side of the open door. Of the C5 palsies, 2 were mild, 3 were moderate, and 2 were severe. Two of the 7 C5 palsies had a delayed (> 24 hours) onset. The C5 palsy incidence after CLF was 2.7% with no side preference. CONCLUSIONS: C5 palsy after cervical decompression for myelopathy is a known occurrence, with a rate of 2.6% in the current study. The authors found that C5 palsies more commonly occur on the open side of the laminoplasty. This could be due to a greater manipulation of the nerve root on the side of the open door or greater stretch of the C5 root on the open-door side. If clinical symptoms and anatomical stenosis are symmetric, the authors recommend creating the laminoplasty hinge on the patient's dominant side to minimize potential loss of dominant proximal arm function.

A case of primary central nervous system lymphoma presenting as a shunt complication.

The authors describe an 82-year-old female with a right frontal ventriculoperitoneal (VP) shunt for long-standing normal pressure hydrocephalus (NPH) who presented with worsening incontinence and gait instability. She was found to have right lateral ventricle collapse around the shunt catheter and subsequently underwent shunt revision, which failed to improve her symptoms. Magnetic resonance imaging (MRI) was obtained on postoperative day two, which demonstrated a ventricular lesion. Endoscopic brain biopsy was performed and a diagnosis of primary central nervous system lymphoma (PCNSL) was made. The authors believe this is the first published case of PCNSL presenting as a VP shunt complication in a patient with NPH.

Big Data in the Clinical Neurosciences.

The clinical neurosciences have historically been at the forefront of innovation, often incorporating the newest research methods into practice. This chapter will explore the adoption, implementation, and refinement of big data and predictive modeling using machine learning within neurosurgery. Initial development of national databases arose from surgeons aiming to improve outcome predictions for patients with traumatic brain injury in the 1960s. In the following decades, other surgical specialties began building databases that left a lasting impact on the current national neurosurgical databases, particularly in spine surgery. Significant contributions to the literature have been made as a result of the numerous registries today, leading to broad quality improvements for neurosurgical patients. Important limitations of large databases do exist, including lack of standardized reporting and challenges in data extraction from medical records. New vistas will include the use of metadata to track human function, performance, and pain in a real-time manner to augment the reliance on traditional patient-reported outcome measures (PROMs). Overall, big data has demonstrated significant utility within neurosurgical research and machine learning-powered analyses have highlighted several promising areas of interest for future exploration.

Intermediate-term clinical and radiographic outcomes with less invasive adult spinal deformity surgery: patients with a minimum follow-up of 4 years.

BACKGROUND: Little information exists regarding longer-term outcomes with minimally invasive spine surgery (MISS), particularly regarding long-segment and deformity procedures. We aimed to evaluate intermediate-term outcomes of MISS for adult spinal deformity (ASD). METHODS: This retrospective review of a prospectively collected multicenter database examined outcomes at 4 or more years following circumferential MIS (cMIS) or hybrid (HYB) surgery for ASD. A total of 53 patients at 8 academic centers satisfied the following inclusion criteria: age > 18 years and coronal Cobb > 20°, pelvic incidence-lumbar lordosis (PI-LL) > 10°, or sagittal vertical axis (SVA) > 5 cm. RESULTS: Radiographic outcomes demonstrated improvements of PI-LL from 16.8° preoperatively to 10.8° and coronal Cobb angle from 38° preoperatively to 18.2° at 4 years. The incidence of complications over the follow-up period was 56.6%. A total of 21 (39.6%) patients underwent reoperation in the thoracolumbar spine, most commonly for adjacent level disease or proximal junctional kyphosis, which occurred in 11 (20.8%) patients. Mean Oswestry Disability Index (ODI) at baseline and years 1 through 4 were 49.9, 33.1, 30.2, 32.7, and 35.0, respectively. The percentage of patients meeting minimal clinically important difference (MCID) (defined as 12% or more from baseline) decreased over time, with leg pain reduction more durable than back pain reduction. CONCLUSIONS: Intermediate-term clinical and radiographic improvement following MISS for ASD is sustained, but extent of improvement lessens over time. Outcome variability exists within a subset of patients not meeting MCID, which increases over time after year two. Loss of improvement over time was more notable in back than leg pain. However, average ODI improvement meets MCID at 4 years after MIS ASD surgery.

Endoscopic transforaminal lumbar interbody fusion without general anesthesia: operative and clinical outcomes in 100 consecutive patients with a minimum 1-year follow-up.

OBJECTIVEOpen spinal fusion surgery is often associated with significant blood loss, postoperative pain, and prolonged recovery times. Seeking to minimize surgical and perioperative morbidity, the authors adopted an endoscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) technique performed without general anesthesia. In this report, they present data on the first 100 patients treated with this procedure.METHODSThe authors conducted a retrospective review of the first 100 patients who underwent awake endoscopic MIS-TLIF at a single institution between 2014 and 2017. Surgery was performed while the patient was sedated but without intubation or the use of general anesthetic or narcotic agents. Long-lasting (liposomal) bupivacaine was used for local analgesia. The discectomy and placement of an expandable interbody graft were performed endoscopically, followed by percutaneous pedicle screw implantation. Inclusion criteria for the procedure consisted of diagnosis of degenerative disc disease with grade I or II spondylolisthesis and evidence of spinal stenosis or nerve impingement with intractable symptomatology.RESULTSOf the first 100 patients, 56 were female and 44 were male. Single-level fusion was performed in 84 patients and two-level fusion in 16 patients. The most commonly fused level was L4-5, representing 77% of all fused levels. The mean (± standard deviation) operative time was 84.5 ± 21.7 minutes for one-level fusions and 128.1 ± 48.6 minutes for two-level procedures. The mean intraoperative blood loss was 65.4 ± 76.6 ml for one-level fusions and 74.7 ± 33.6 ml for two-level fusions. The mean length of hospital stay was 1.4 ± 1.0 days. Four deaths occurred in the 100 patients; all four of those patients died from complications unrelated to surgery. In 82% of the surviving patients, 1-year follow-up Oswestry Disability Index (ODI) data were available. The mean preoperative ODI score was 29.6 ± 15.3 and the mean postoperative ODI score was 17.2 ± 16.9, which represents a significant mean reduction in the ODI score of -12.3 using a two-tailed paired t-test (p = 0.000001). In four cases, the surgical plan was revised to include general endotracheal anesthesia intraoperatively and was successfully completed. Other complications included two cases of cage migration, one case of osteomyelitis, and one case of endplate fracture; three of these complications occurred in the first 50 cases.CONCLUSIONSThis series of the first 100 patients to undergo awake endoscopic MIS-TLIF demonstrates outcomes comparable to those reported in our earlier papers. This procedure can provide a safe and efficacious option for lumbar fusion with less morbidity than open surgery. Further refinements in surgical technique and technologies will allow for improved success.

Preoperative SPECT imaging as a tool for surgical planning in patients with axial neck and back pain.

OBJECTIVE: Hybrid SPECT with CT imaging has been used to help elucidate pain generators in patients with axial neck and back pain, identifying potential sites for treatment. Few studies have examined its role in spine surgery and most literature focuses on its use postoperatively. The authors describe the largest series to date of patients with symptomatic spondylosis who underwent preoperative SPECT imaging for surgical planning. METHODS: A retrospective medical and imaging record review was conducted to identify patients who underwent SPECT or SPECT/CT studies between January 2014 and May 2018. Patients who underwent spine surgical intervention for spondylosis with primary symptoms of axial neck or back pain and who had evidence of hypermetabolic foci on spinal SPECT imaging were included. Only those patients who subsequently underwent surgery on a spinal level associated with increased radiotracer uptake were included in the analysis. Patient baseline and demographic information, and data pertaining to SPECT imaging, surgical planning, and postoperative care were collected and analyzed. RESULTS: A total of 23 patients with an average age at surgery of 60.0 ± 11.0 years were included. Fifteen patients (65.2%) were male. A total of 53 spinal levels were treated, with an average of 2.30 levels treated per patient. All patients underwent fusion surgery, either lumbar (n = 14), with interbody fusion most commonly used (64.2%); or cervical (n = 9), with anterior cervical discectomy and fusion (66.6%) being the most common. The average length of hospital stay was 3.45 ± 2.32 days. One patient developed a wound infection postoperatively, requiring readmission. At the 3-month follow-up, 18 patients (78.3%) reported clinical improvement in pain. Eleven patients (47.8%) reported complete symptom resolution at the 6-month follow-up. At 1 year postoperatively, 19 patients (82.6%) reported significant relief of their symptoms following surgery. CONCLUSIONS: This is the largest series to date describing patients with axial neck and back pain who underwent preoperative SPECT imaging and subsequent surgical intervention on the affected spinal levels. The results demonstrate that SPECT imaging may be a useful adjunct to guide surgical planning, resulting in substantial clinical improvement following surgery.

Reductions in length of stay, narcotics use, and pain following implementation of an enhanced recovery after surgery program for 1- to 3-level lumbar fusion surgery.

OBJECTIVELumbar fusion is typically associated with high degrees of pain and immobility. The implementation of an enhanced recovery after surgery (ERAS) approach has been successful in speeding the recovery after other surgical procedures. In this paper, the authors examined the results of early implementation of ERAS for lumbar fusion.METHODSBeginning in March 2018 at the authors' institution, all patients undergoing posterior, 1- to 3-level lumbar fusion surgery by any of 3 spine surgeons received an intraoperative injection of liposomal bupivacaine, immediate single postoperative infusion of 1-g intravenous acetaminophen, and daily postoperative visits from the authors' multidisciplinary ERAS care team. Non-English- or non-Spanish-speaking patients and those undergoing nonelective or staged procedures were excluded. Reviews of medical records were conducted for the ERAS cohort of 57 patients and a comparison group of 40 patients who underwent the same procedures during the 6 months before implementation.RESULTSGroups did not differ significantly with regard to sex, age, or BMI (all p > 0.05). Length of stay was significantly shorter in the ERAS cohort than in the control cohort (2.9 days vs 3.8 days; p = 0.01). Patients in the ERAS group consumed significantly less oxycodone-acetaminophen than the controls on postoperative day (POD) 0 (408.0 mg vs 1094.7 mg; p = 0.0004), POD 1 (1320.0 mg vs 1708.4 mg; p = 0.04), and POD 3 (1500.1 mg vs 2105.4 mg; p = 0.03). Postoperative pain scores recorded by the physical therapy and occupational therapy teams and nursing staff each day were lower in the ERAS cohort than in controls, with POD 1 achieving significance (4.2 vs 6.0; p = 0.006). The total amount of meperidine (8.8 mg vs 44.7 mg; p = 0.003) consumed was also significantly decreased in the ERAS group, as was ondansetron (2.8 mg vs 6.0 mg; p = 0.02). Distance ambulated on each POD was farther in the ERAS cohort, with ambulation on POD 1 (109.4 ft vs 41.4 ft; p = 0.002) achieving significance.CONCLUSIONSIn this very initial implementation of the first phase of an ERAS program for short-segment lumbar fusion, the authors were able to demonstrate substantial positive effects on the early recovery process. Importantly, these effects were not surgeon-specific and could be generalized across surgeons with disparate technical predilections. The authors plan additional iterations to their ERAS protocols for continued quality improvements.

The use of dehydrated amniotic membrane allograft for augmentation of dural repair in transsphenoidal endoscopic endonasal resection of pituitary adenomas.

BACKGROUND: In transsphenoidal endoscopic endonasal surgery (TEES), watertight separation of the sinonasal cavity and intracranial compartment is the primary goal of closure. However, even when meticulous closure technique is implemented, cerebrospinal fluid (CSF) leaks, dural scarring, and meningitis may result. Particularly when intraoperative CSF leak occurs, materials that facilitate the creation of a watertight seal that inhibits disease transition and minimizes inflammatory response after durotomy are sought. Dehydrated amniotic membrane (DAM) allograft appears to confer these attributes as studies have shown it augments epithelialization, facilitates wound healing, and minimizes and impedes bacterial growth. We detail the use of DAM allograft to augment sellar closures after TEES. METHODS: We conducted a feasibility study, retrospectively reviewing our institution's database of TEES for resection of pituitary adenomas in which DAM was utilized to supplement sellar closure. RESULTS: One hundred twenty transsphenoidal surgery cases with DAM were used during sellar closure, with a 49.2% intraoperative CSF leak rate. Of this cohort, two patients experienced postoperative CSF leak (1.7%), and no patients developed meningitis. CSF leak rate for TEES-naïve patients was 0.9%. CONCLUSIONS: This feasibility study demonstrates that dehydrated amniotic membrane allograft can be safely utilized as an adjunct during sellar closures for TEES for pituitary adenoma resection with very low rates of CSF leak and meningitis.

Characteristics and Outcomes of Patients Treated with Cervical Spine Fusion at High Volume Hospitals.

BACKGROUND: High volume (HV) has been associated with improved outcomes in various neurosurgical procedures. The objective of this study was to explore the regional distribution of HV spine centers for cervical spine fusion and compare characteristics and outcomes for patients treated at HV centers versus lower volume centers. METHODS: The National Inpatient Sample database 2016-2020 was queried for patients undergoing cervical spine fusion for degenerative pathology. HV was defined as case-loads greater than 2 standard deviations above the mean. Patient characteristics, procedures, and outcomes were compared. RESULTS: Of 3895 hospitals performing cervical spine fusion for degenerative pathology, 28 (0.76%) were HV. The Mid-Atlantic and West South Central regions had the highest number of HV hospitals. HV hospitals were more likely to perform open anterior fusion surgeries (P < 0.01). Patients treated at HV hospitals were less likely to have severe symptomatology or comorbidities (P < 0.01 for all). When controlling for severity and demographics on multivariate analysis, HV centers had higher odds of length of stay ≤1 day, favorable discharge, and decreased total charges. CONCLUSIONS: Patients who underwent cervical spine fusion surgery at HV hospitals were less complex and had increased odds of length of stay ≤1, favorable discharge, and total charges in the lower 25th percentile than patients treated at non-HV hospitals. Physician comfort, patient selection, institutional infrastructure, and geographic characteristics likely play a role.

Single-Position Lateral Approach for Revision Thoracolumbar Corpectomy With Delayed Ipsilateral Kidney Atrophy: Technical Note and Discussion of Complications.

Improvements in navigation technology have enabled surgeons to safely offer single-position fusion surgeries, demonstrating shorter operating times and reduced length of stay (LOS) as compared to traditional lateral and prone dual-position surgeries. However, no studies to date describe revision thoracolumbar corpectomy with simultaneous posterior rod removal and replacement in the lateral position. Furthermore, this is the first reported complication of delayed ipsilateral kidney atrophy following lateral lumbar surgery. A 56-year-old male patient with history of metastatic hepatocellular carcinoma and complex surgical history for a prior T12 pathologic fracture presented to the clinic for follow-up. Computed tomography (CT) demonstrated bilateral broken rods and subsidence of the T12 interbody cage, for which he underwent revision T12 corpectomy and posterior instrumentation revision via a single-position, left-sided lateral approach. Simultaneous exposure and removal of the broken rods enabled the placement of two short temporary rods between the T11-L1 screws posteriorly, allowing for rod distraction and the placement of the expandable corpectomy cage into the appropriate position. On follow-up cancer surveillance imaging, the left kidney became progressively atrophic within six months after surgery. According to a review of PubMed, Scopus, and Embase databases, we describe the first reported case of a single-position thoracolumbar revision corpectomy with simultaneous rod replacement. Of particular importance in this technique is the use of temporary rod placement for distraction across the index level to facilitate interbody cage placement. Furthermore, we discussed the first reported complication of delayed ipsilateral kidney atrophy following lateral lumbar fusion.

Associations with daily opioid use during hospitalization following lumbar fusion: A contemporary cohort study.

BACKGROUND: Predicting opioid use after lumbar spine fusion remains a challenge. The aim of this study was to identify clinical and demographic parameters that could be associated with opioid use trends during hospitalization after lumbar spine fusion. METHODS: A cohort study of prospective data for all lumbar fusions performed by single surgeon for an 18-month period from 2019 to 2020 was conducted. Univariable and multivariable linear regression analyses were used to assess associations. RESULTS: Amongst the overall cohort of 136 lumbar fusion patients, the mean age was 66.1 ± 10 years, there was an average of 1.7 ± levels treated. Overall, mean opioid use for total stay was 276 ± 360 morphine milligram equivalents (MME), with the greatest amount on postoperative day 1 (POD1) with 81.6 ± 86 MME. Multivariable linear analysis identified older age (-9.9 MME/year; P < 0.01), male gender (-130 MME; P = 0.03) and thoracolumbar interfascial plane (TLIP) block (-144 MME; P = 0.02) all independently were associated with significantly lower opioid use during overall hospitalization. Older age (P < 0.01), POD1 pain in back (P < 0.01), and TLIP use (P < 0.02) also independently were associated significantly lower opioid use on POD1. CONCLUSIONS: Significant reductions in opioid use during hospitalization after lumbar spine fusion were associated with patients that were older, male, and had a TLIP block used. The maximum absolute opioid use was on POD1. We were able to quantify these trends on a daily gradient, which lays the conceptual groundwork to develop personalized algorithms which can model opioid use during hospitalization prior to surgery.

Ancient Schwannoma Presenting at the Cauda Equina: A Report of a Rare Case.

Ancient schwannoma is an uncommon variant of schwannoma. While many reports have presented defining histologic and clinical features of ancient schwannoma, there are only a very few cases in the literature, to our knowledge, of ancient schwannoma presenting at the cauda equina. The current report of ancient schwannoma presenting at the cauda equina adds to the literature and discusses the identification of specific histologic characteristics, the role of conservative medical management, surgical resection, and prognostication in this select subset of patients.

Defining the Time Benefit of Awake Versus General Anesthesia for Single-Level Lumbar Spine Surgery.

BACKGROUND: Awake anesthesia with monitored anesthesia care (MAC) might confer time benefits compared with traditional general anesthesia (GA) in the setting of single-level lumbar spine surgery. Therefore, we sought to define the quantitative time difference spent in the operating room between the MAC and GA approaches for single-level lumbar spine surgery. METHODS: A prospectively maintained database of the senior surgeon was reviewed for single-level lumbar spine surgeries from 2019 to 2020 performed with the patient under either GA or MAC. The patient demographics, clinical features, time in the operating room, and postoperative outcomes were all summarized and statistically compared. RESULTS: A total of 53 patients satisfied all the selection criteria, with 25 (47%) in the GA group and 28 (53%) in the MAC group. Overall, most patients were men, with a median age of 60 years. The 2 groups were statistically comparable with respect to the demographics and preoperative anesthesia parameters. The time from room arrival to sedation start (median time, 26 vs. 38 minutes; P < 0.01), sedation time (median time, 55 vs. 87 minutes; P < 0.01), and time from sedation end to room exit (median time, 4 vs. 13 minutes; P < 0.01) were all significantly shorter for the MAC group. Additionally, the estimated blood loss was less in the MAC group (P < 0.01). CONCLUSIONS: We found MAC to be a safe anesthesia option for use in single-level lumbar spine surgery, which led to statistically significant benefits regarding the time under sedation and time in the operating room compared with GA. Future studies are required to understand whether MAC will require other synergistic measures to generate observable change at a health systems level.

Use of Cervical Disk Arthroplasty to Treat Noncontiguous Cervical Disk Herniations.

BACKGROUND: Cervical disk arthroplasty is now a widely accepted alternative to anterior cervical interbody fusion, which is known to reduce normal cervical motion and increase the incidence of adjacent segment disease. Although multiple studies report the use of cervical disk arthroplasty to treat multilevel cervical disease, this is the first report in the literature detailing the placement of multiple, noncontiguous artificial disks. CASE DESCRIPTION: We describe a 41-year-old male who presented with myelopathy and left upper extremity radiculopathy resulting from 2 cervical disk herniations separated by a normal intervening level. He underwent an anterior cervical diskectomy and placement of an artificial disk prosthesis at cervical (C) 4-5 and C6-7 while leaving C5-6 intact. CONCLUSIONS: This approach serves to preserve cervical motion, spinal stability, and lordosis across all 3 levels, thus demonstrating that it is a viable alternative to a multilevel anterior cervical interbody fusion.

Endoscopic Lumbar Interbody Fusion.

Spine surgeons have recently developed more advanced and less invasive techniques. One significant example of recent surgical innovation is the advent of endoscopic-assisted spine surgery. Endoscopic lumbar interbody fusions are increasingly used to treat lumbar degenerative disease in a minimally invasive approach that minimizes pain and maximizes outcomes. Numerous technical refinements to ultraminimally invasive approaches have occurred since their initial use, which has resulted in substantial clinical benefit for patients that remains stable over time. Serious complications can occur and thus, the spine surgeon adopting endoscopic techniques must be aware of the early learning curve.

The Value of a Synthetic Model-based Training Lab to Increase Proficiency with Endoscopic Approaches to the Spine.

INTRODUCTION: The learning curve associated with endoscopic approaches to the spine is well established. In this study, we present our endoscopic training methodology and discuss the concepts and rationale of laboratory training as it relates to improving comfort and skill with endoscopic techniques. MATERIALS AND METHODS: A three-part endoscopic training laboratory for neurosurgical trainees and attendings was organized at the University of Miami, which included a lecture, instrumentation demonstration, and both synthetic model and cadaveric practice sessions. Participants completed pre- and post-lab surveys gauging their comfort and competency in the transforaminal approach to the lumbar spine. RESULTS: There were a total of 22 participants, with eight completing the pre-lab survey and 10 completing the post-lab survey. Sixteen participants engaged in the lab practical, with six of these participants performing the transforaminal approach on both the model and the cadaver. An increase in comfort level was demonstrated on the post-lab survey (5.9/10) for the transforaminal approach as compared to the pre-lab survey (2.6/10). Additionally, participants found the training model to be an effective teaching aid for the transforaminal technique (8.8/10). CONCLUSIONS: We believe that our study demonstrates the utility of simulated model-based training for gaining comfort and proficiency with endoscopic approaches to the spine and introduces a safe, cost-effective method of educating practitioners on novel endoscopic approaches.

Awake Endoscopic Transforaminal Lumbar Interbody Fusion: A Technical Note.

BACKGROUND: Advances in modern spinal fusion techniques have allowed for less peri-operative morbidity and more rapid recovery from surgery. The addition of endoscopy to minimally invasive surgery (MIS) fusion techniques represents the latest progression of efforts to minimize the impact of surgical intervention. TECHNIQUE: MIS transforaminal lumbar interbody fusion (TLIF) is performed endoscopically through a sub-centimeter working portal. Patients undergo light conscious sedation and remain awake to facilitate feedback with the surgeon and enhance post-operative recovery. RESULTS: Previously reported results of the first 100 cases performed by the senior author at a single institution are summarized. This cohort has been characterized by brief post-operative length of stay, low complication profile, and marked improvement in patient-reported outcomes scores, with no cases of pseudarthrosis at 1-year follow up. CONCLUSIONS: The latest technical considerations and adaptations of a novel technique for endoscopic MIS spinal fusion without general anesthesia are described. A refined surgical technique and anesthetic protocol are presented in detail with recommendations for the successful implementation and performance of the procedure.

Long-Term Clinical Outcomes With the Activ-L Lumbar Arthroplasty System.

BACKGROUND: Low back pain (LBP) due to degenerative disc disease (DDD) is the most common occupational disorder worldwide. Lumbar total disc replacement (LTDR) has provided an alternative to rigid fusion to relieve pain with less motion restriction. We present clinical results with long-term follow-up from a single-center, single-surgeon series of patients treated with the Activ-L artificial disc. METHODS: Thirty-three patients with symptomatic single-level DDD who failed nonsurgical therapy for a minimum of 6 months underwent single-level arthroplasty with the Activ-L system between 2007 and 2012. Demographic, preoperative, and postoperative data were collected prospectively. Clinical factors reviewed included occupational status, sensory deficits, functional status determined by Oswestry Disability Index (ODI), back pain, leg pain, pain medication consumption, and radiographic imaging. RESULTS: Average age at surgery was 38.0 ± 7.8 years, and the majority of patients were male (60.6%). Average follow-up was 2.7 ± 1.7 years. Average ODI at preoperative baseline was 54.6 ± 13.5, with scores significantly improved at 6 weeks (28.6 ± 17.4, P < .0001), 3 months (24.1 ± 16.8, P < .0001), 6 months (22.3 ± 16.3, P < .0001), 1 year (18.8 ± 15.3, P < .0001), and final follow-up (15.6 ± 16.4, P < .0001). Most patients (87.8%) reported pain medication usage within 14 days of baseline evaluation, with consumption decreasing significantly at 1-year (34.5%, P < .0001) and long-term follow-up (21.2%, P < .0001). One patient experienced mild unilateral graft subsidence at 1 year, which remained stable on radiographs at 5 years. None of the prostheses required revision surgery. CONCLUSIONS: The Activ-L disc replacement system is safe and effective for treating single-level lumbar DDD. Patients reported significant improvement in functional outcomes and decreases in pain medication consumption. Further investigation of the Activ-L system in larger populations is warranted. CLINICAL RELEVANCE: LBP is a common cause of disability worldwide, and better treatment options are needed to improve outcomes, including pain and mobility. Spine surgeons may choose the Activ-L disc replacement as a safe and effective treatment for LBP caused by single-level lumbar DDD.

Use of Single-Photon Emission Computed Tomography Imaging for Hypermetabolic Facet Identification in Diagnosis of Cervical and Axial Back Pain.

BACKGROUND: Few studies have used hybrid single-photon emission computed tomography (SPECT)/computed tomography (CT) scan to identify degenerative facet disease. We aimed to determine the incidence of hypermetabolic facets on SPECT/CT imaging in patients with axial neck or back pain to elucidate the value of SPECT/CT scan in identifying pain generators. METHODS: A retrospective review of adult patients with axial neck or back pain was conducted. A total of 190 patients underwent high-resolution SPECT/CT imaging using a standardized protocol from January 2010 to April 2018. Facet joints with increased radionuclide uptake on SPECT imaging were characterized as hypermetabolic. Number, level, and laterality of hypermetabolic facets were recorded based on review of imaging and radiologist impressions. RESULTS: The average age of the patients was 58 ± 13 years, and 51% of patients were men. A total of 85 patients (48%) demonstrated zygapophyseal joint hypermetabolism (ZJH) on SPECT imaging. A total of 202 hypermetabolic facets were identified, indicating the average number of facets with ZJH was 2.38 ± 1.91. Of patients with a positive scan, lumbar facets were most commonly affected (69% of ZJH) followed by cervical (24%) and thoracic regions (6%). C1-2 and C2-3 (22% each of cervical ZJH) and L4-5 (32% of lumbar ZJH) were most commonly affected in the cervical and lumbar regions, respectively. CONCLUSIONS: Nearly half of all patients with axial neck or back pain demonstrated ZJH on SPECT/CT imaging, supporting ZJH sites as potential pain generators and targets for treatment. Our results support the role for SPECT/CT imaging in the workup of patients with axial neck or back pain, which may reduce invasive diagnostic procedures and aid in treatment planning.

Minimally Invasive Spinal Deformity Surgery: Analysis of Patients Who Fail to Reach Minimal Clinically Important Difference.

BACKGROUND: It is well known that clinical improvements following surgical intervention are variable. While all surgeons strive to maximize reliability and degree of improvement, certain patients will fail to achieve meaningful gains. We aim to analyze patients who failed to reach minimal clinically important difference (MCID) in an effort to improve outcomes for minimally invasive deformity surgery. METHODS: Data were collected on a multicenter registry of minimally invasive surgery adult spinal deformity surgeries. Patient inclusion criteria were age ≥18 years, coronal Cobb ≥20 degrees, pelvic incidence-lumbar lordosis ≥10 degrees, or a sagittal vertical axis >5 cm. All patients had minimum 2 years' follow-up (N = 222). MCID was defined as 12.8 or more points of improvement in the Oswestry Disability Index. Up to 2 different etiologies for failure were allowed per patient. RESULTS: We identified 78 cases (35%) where the patient failed to achieve MCID at long-term follow-up. A total of 82 identifiable causes were seen in these patients with 14 patients having multiple causes. In 6 patients, the etiology was unclear. The causes were subclassified as neurologic, medical, structural, under treatment, degenerative progression, traumatic, idiopathic, and floor effects. In 71% of cases, an identifiable cause was related to the spine, whereas in 35% the cause was not related to the spine. CONCLUSIONS: Definable causes of failed MIS ASD surgery are often identifiable and similar to open surgery. In some cases the cause is treatable and structural. However, it is also common to see failure due to pathologies unrelated to the index surgery.