Rate of Reoperation Following Decompression-Only Procedure for Lumbar Degenerative Spondylolisthesis: A Systematic Review of Literature.

Background: Management of lumbar degenerative spondylolisthesis with decompression-only procedure has been performed for its added benefit of a shorter duration of surgery, lower blood loss, and shorter hospital stay. However, reported failure rates for decompression-only procedures vary depending on the methods utilized for decompression. Hence, we aim to identify the failure rates of individual methods of decompression-only procedures performed for degenerative lumbar spondylolisthesis. Methods: An independent systematic review of 4 scientific databases (PubMed, Scopus, clinicaltrials.gov, Web of Science) was performed to identify relevant articles as per the preferred reporting in systematic reviews and meta-analysis guidelines. Studies reporting on failure rates defined by reoperation at the index level following decompression-only procedure for degenerative lumbar spondylolisthesis were included for analysis. Studies were appraised using ROBINS tool of Cochrane, and analysis was performed using the Open Meta[Analyst] software. Results: The overall failure rate of decompression-only procedure was 9.1% (95% confidence interval [CI] [6.5-11.7]). Furthermore, open decompression had failure rate of 10.9% (95% CI [6.0-15.8]), while microendoscopic decompression had failure rate of 6.7% (95% CI [2.9-10.6]). The failure rate gradually increased from 6.9% (95% CI [2.0-11.7]) at 1 year to 7% (95% CI [3.6-10.3]), 11.7% (95% CI [4.5-18.9]), and 11.7% (95% CI [6.6-16.7]) at 2, 3, and 5 years, respectively. Single level decompression had a failure rate of 9.6% (95% CI [6.3-12.9]), while multilevel decompression recorded a failure rate of 8.7% (95% CI [5.6-11.7]). Conclusion: High-quality evidence on the decompression-only procedure for degenerative spondylolisthesis is limited. The decompression-only procedure had an overall failure rate of 9.1% without significant differences between the decompression techniques. Level of Evidence: Level IV. See Instructions for Authors for a complete description of levels of evidence.

What Is the Evidence Supporting Osteobiologic Use in Revision Anterior Cervical Discectomy and Fusion?

STUDY DESIGN: Systematic literature review. OBJECTIVE: To analyze the literature and describe the evidence supporting osteobiologic use in revision anterior cervical discectomy and fusion (ACDF) surgery. METHODS: A systematic search of PubMed/MEDLINE, EMBASE, Cochrane library, and ClinicalTrials.gov databases was conducted for literature reporting the use of osteobiologics in revision ACDF. We searched for studies reporting outcomes of using any osteobiologic use in revision ACDF surgeries (independently of the number of levels) in the above databases. RESULTS: There are currently no studies in the literature describing the outcome and comparative efficacy of diverse osteobiologic agents in the context of revision ACDF surgery. A majority of the current evidence is based only upon studies involving primary ACDF surgery. CONCLUSION: The current study highlights the paucity of literature evidence on the role of diverse osteobiologics in revision ACDF, and foregrounds the need for high-quality evidence on this subject.

AO Spine Guideline for the Use of Osteobiologics (AOGO) in Anterior Cervical Discectomy and Fusion for Spinal Degenerative Cases.

STUDY DESIGN: Guideline. OBJECTIVES: To develop an international guideline (AOGO) about the use of osteobiologics in anterior cervical discectomy and fusion (ACDF) for treating degenerative spine conditions. METHODS: The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence was collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. RESULTS: Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about the use of osteobiologic for single- or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human bone morphogenetic protein-2 (BMP-2) in common clinical situations. Surgeons are recommended to choose 1 graft over another or 1 osteobiologic over another primarily based on clinical situation, and the costs and availability of the materials. CONCLUSION: This AOGO guideline is the first to provide recommendations for the use of osteobiologics in ACDF. Despite the comprehensive searches for evidence, there were few studies completed with small sample sizes and primarily as case series with inherent risks of bias. Therefore, high-quality clinical evidence is demanded to improve the guideline.

Dosing Strategy for Osteobiologics Used in ACDF Surgery: Influence on Fusion Rates and Associated Complications. A Systematic Literature Review.

STUDY DESIGN: Systematic review. OBJECTIVE: To assess the available evidence related to dose-dependent effectiveness (i.e., bone fusion) and morbidity of osteobiologics used in anterior cervical discectomy and fusion (ACDF). METHODS: Studies with more than 9 adult patients with degenerated/herniated cervical discs operated for one-to four-levels ACDF reporting used osteobiologics doses, fusion rates at six months or later, and related comorbidities were included. PubMed, EMBASE, ClinicalTrials, and Cochrane were searched through September 2021. Data extracted in spread sheet and risk of bias assessed using MINORS and Rob-2. RESULTS: Sixteen studies were selected and sub-grouped into BMP and non-BMP osteobiologics. For the 10 BMP studies, doses varied from 0.26 to 2.1 mg in 649 patients with fusion rates of 95.3 to 100% at 12 months. For other osteobiologics, each of six studies reported one type of osteobiologic in certain dose/concentration/volume in a total of 580 patients with fusion rates of 6.8 to 96.9% at 12 months. Risk of bias was low in three of the 13 non-randomized (18.75%) and in all the three randomized studies (100%). CONCLUSIONS: Taking into account the inconsistent reporting within available literature, for BMP usage in ACDF, doses lower than 0.7 mg per level can achieve equal successful fusion rates as higher doses, and there is no complication-free dose proved yet. It seems that the lower the dose the lower the incidence of serious complications. As for non-BMP osteobiologics the studies are very limited for each osteobiologic and thus conclusions must be drawn individually and with caution.

A component method to delineate surgical spine implants for proton Monte Carlo dose calculation.

PURPOSE: Metallic implants have been correlated to local control failure for spinal sarcoma and chordoma patients due to the uncertainty of implant delineation from computed tomography (CT). Such uncertainty can compromise the proton Monte Carlo dose calculation (MCDC) accuracy. A component method is proposed to determine the dimension and volume of the implants from CT images. METHODS: The proposed component method leverages the knowledge of surgical implants from medical supply vendors to predefine accurate contours for each implant component, including tulips, screw bodies, lockers, and rods. A retrospective patient study was conducted to demonstrate the feasibility of the method. The reference implant materials and samples were collected from patient medical records and vendors, Medtronic and NuVasive. Additional CT images with extensive features, such as extended Hounsfield units and various reconstruction diameters, were used to quantify the uncertainty of implant contours. RESULTS: For in vivo patient implant estimation, the reference and the component method differences were 0.35, 0.17, and 0.04 cm3 for tulips, screw bodies, and rods, respectively. The discrepancies by a conventional threshold method were 5.46, 0.76, and 0.05 cm3 , respectively. The mischaracterization of implant materials and dimensions can underdose the clinical target volume coverage by 20 cm3 for a patient with eight lumbar implants. The tulip dominates the dosimetry uncertainty as it can be made from titanium or cobalt-chromium alloys by different vendors. CONCLUSIONS: A component method was developed and demonstrated using phantom and patient studies with implants. The proposed method provides more accurate implant characterization for proton MCDC and can potentially enhance the treatment quality for proton therapy. The current proof-of-concept study is limited to the implant characterization for lumbar spine. Future investigations could be extended to cervical spine and dental implants for head-and-neck patients where tight margins are required to spare organs at risk.

Automatic Localization and Brand Detection of Cervical Spine Hardware on Radiographs Using Weakly Supervised Machine Learning.

Purpose: To develop an end-to-end pipeline to localize and identify cervical spine hardware brands on routine cervical spine radiographs. Materials and Methods: In this single-center retrospective study, patients who received cervical spine implants between 2014 and 2018 were identified. Information on the implant model was retrieved from the surgical notes. The dataset was filtered for implants present in at least three patients, which yielded five anterior and five posterior hardware models for classification. Images for training were manually annotated with bounding boxes for anterior and posterior hardware. An object detection model was trained and implemented to localize hardware on the remaining images. An image classification model was then trained to differentiate between five anterior and five posterior hardware models. Model performance was evaluated on a holdout test set with 1000 iterations of bootstrapping. Results: A total of 984 patients (mean age, 62 years ± 12 [standard deviation]; 525 women) were included for model training, validation, and testing. The hardware localization model achieved an intersection over union of 86.8% and an F1 score of 94.9%. For brand classification, an F1 score, sensitivity, and specificity of 98.7% ± 0.5, 98.7% ± 0.5, and 99.2% ± 0.3, respectively, were attained for anterior hardware, with values of 93.5% ± 2.0, 92.6% ± 2.0, and 96.1% ± 2.0, respectively, attained for posterior hardware. Conclusion: The developed pipeline was able to accurately localize and classify brands of hardware implants using a weakly supervised learning framework.Keywords: Spine, Convolutional Neural Network, Deep Learning Algorithms, Machine Learning Algorithms, Prostheses, Semisupervised Learning Supplemental material is available for this article. © RSNA, 2022See also commentary by Huisman and Lessmann in this issue.

COVID-19 doesn't need lockdowns to destroy jobs: The effect of local outbreaks in Korea.

Unlike most countries, Korea did not implement a lockdown in its battle against COVID-19, instead successfully relying on testing and contact tracing. Until the summer of 2020, only one region, Daegu-Gyeongbuk, had a significant number of infections, traced to a religious sect. This allows us to estimate the causal effect of the outbreak on the labor market using difference-in-differences. We find that a one per thousand increase in infections caused a 2 to 3 percent drop in local employment in the early spring. We also find that employment losses caused by local outbreaks in the absence of lockdowns were (i) mainly due to reduced hiring by small establishments, (ii) concentrated in the accommodation/food, education, real estate, and transportation industries, and (iii) worst for economically vulnerable workers who are less educated, young, in low-wage occupations, and on temporary contracts, even controlling for industry effects. These patterns are similar to what we observed in the US and UK: The unequal effects of COVID-19 were the same with or without lockdowns. Our findings are consistent with the lifting of lockdowns having led to only modest employment recoveries in the US and UK, absent larger drops in infection rates.

Risk Factors of Extended Hospital Stay After One-Level Anterior Cervical Discectomy Fusion or Disc Replacement: Results from 1004 Patients in Food and Drug Administration Trials.

BACKGROUND: Extended length of stay (LOS) after surgery is costly to the health care system and can be distressing to the patient and family. Previous studies have shown conflicting data on factors associated with increased LOS and are limited by using multiple different surgeries. Our study seeks to analyze factors that are associated with extended LOS. OBJECTIVE: The objective of this study was to analyze data from 2 Food and Drug Administration trials of one-level cervical surgery to identify risk factors that are associated with extended LOS in the hospital. METHODS: Extended LOS was defined to be >1 day. Patients with LOS ≤1 day were compared with those with LOS >1 day. Data from the BRYAN and Prestige ST Trial (n = 1004) were analyzed. Subjects with LOS ≤1 day were compared with those with LOS >1 day. Variables analyzed for their effect on LOS included demographic characteristics, patient-reported outcome measures, preoperative medical conditions, preoperative neurologic status, and intraoperative factors. RESULTS: A total of 912 patients (90.84%) had an LOS ≤1 day and 92 patients (9.16%) had an extended LOS >1 day. Weak narcotic medication use (P = 0.021; odds ratio [OR], 1.72), Nurick gait (P = 0.019; OR, 1.796), and operative time (P < 0.0001; OR, 2.062) were found to significantly affect LOS. CONCLUSIONS: Nurick gait, operative time, and history of weak narcotic use are associated with extended hospital stay. These data may be useful in preoperatively counseling patients, developing quality metrics for hospitals, and helping create financial models for cost/diagnosis-related group reimbursement for single-level anterior cervical surgery.

Derivation of notochordal cells from human embryonic stem cells reveals unique regulatory networks by single cell-transcriptomics.

Intervertebral disc degeneration (IDD) is a public health dilemma as it is associated with low back and neck pain, a frequent reason for patients to visit the physician. During IDD, nucleus pulposus (NP), the central compartment of intervertebral disc (IVD) undergo degeneration. Stem cells have been adopted as a promising biological source to regenerate the IVD and restore its function. Here, we describe a simple, two-step differentiation strategy using a cocktail of four factors (LDN, AGN, FGF, and CHIR) for efficient derivation of notochordal cells from human embryonic stem cells (hESCs). We employed a CRISPR/Cas9 based genome-editing approach to knock-in the mCherry reporter vector upstream of the 3' untranslated region of the Noto gene in H9-hESCs and monitored notochordal cell differentiation. Our data show that treatment of H9-hESCs with the above-mentioned four factors for 6 days successfully resulted in notochordal cells. These cells were characterized by morphology, immunostaining, and gene and protein expression analyses for established notochordal cell markers including FoxA2, SHH, and Brachyury. Additionally, pan-genomic high-throughput single cell RNA-sequencing revealed an efficient and robust notochordal differentiation. We further identified a key regulatory network consisting of eight candidate genes encoding transcription factors including PAX6, GDF3, FOXD3, TDGF1, and SOX5, which are considered as potential drivers of notochordal differentiation. This is the first single cell transcriptomic analysis of notochordal cells derived from hESCs. The ability to efficiently obtain notochordal cells from pluripotent stem cells provides an additional tool to develop new cell-based therapies for the treatment of IDD.

On the Intergenerational Transmission of Economic Status.

We present a model in which human capital investments occur over the life cycle and across generations, à la Becker and Tomes. The human capital technology features multiple stages of childhood investments, college, and life cycle accumulation. The model can explain a wide range of intergenerational relationships while remaining empirically consistent with cross-sectional inequality. Much of the latter is determined by early investments in children, so that borrowing constraints faced by young parents are important for understanding the persistence of economic status across generations. Education subsidies, especially early on, can significantly reduce the intergenerational persistence of economic status.

Frequency and Acceptability of Adverse Events After Anterior Cervical Discectomy and Fusion: A Survey Study From the Cervical Spine Research Society.

PURPOSE: Anterior cervical discectomy and fusion has a low but well-established profile of adverse events. The goal of this study was to gauge surgeon opinion regarding the frequency and acceptability of these events. METHODS: A 2-page survey was distributed to attendees at the 2015 Cervical Spine Research Society (CSRS) meeting. Respondents were asked to categorize 18 anterior cervical discectomy and fusion-related adverse events as either: "common and acceptable," "uncommon and acceptable," "uncommon and sometimes acceptable," or "uncommon and unacceptable." Results were compiled to generate the relative frequency of these responses for each complication. Responses for each complication event were also compared between respondents based on practice location (US vs. non-US), primary specialty (orthopedics vs. neurosurgery) and years in practice. RESULTS: Of 150 surveys distributed, 115 responses were received (76.7% response rate), with the majority of respondents found to be US-based (71.3%) orthopedic surgeons (82.6%). Wrong level surgery, esophageal injury, retained drain, and spinal cord injury were considered by most to be unacceptable and uncommon complications. Dysphagia and adjacent segment disease occurred most often, but were deemed acceptable complications. Although surgeon experience and primary specialty had little impact on responses, practice location was found to significantly influence responses for 12 of 18 complications, with non-US surgeons found to categorize events more toward the uncommon and unacceptable end of the spectrum as compared with US surgeons. CONCLUSIONS: These results serve to aid communication and transparency within the field of spine surgery, and will help to inform future quality improvement and best practice initiatives.

Comparing Quality of Life in Cervical Spondylotic Myelopathy with Other Chronic Debilitating Diseases Using the Short Form Survey 36-Health Survey.

BACKGROUND: Although cervical spondylotic myelopathy (CSM) can be devastating, its relative impact on general health remains unclear. Patient responses to the Short Form Survey 36-Health Survey (SF-36) Physical Component Summary (PCS)/Mental Component Summary (MCS) were compared between CSM and other diseases to evaluate their respective impacts on quality of life. The objective of this study was to compare SF-36 PCS/MCS scores in CSM with population and disease-specific norms. METHODS: Retrospective analysis of a prospective, multicenter AOSpine North American CSM Study database. Inclusion criteria were symptomatic disease, age older than 18 years, cord compression on magnetic resonance imaging or computed tomography myelography, and baseline SF-36 values. SF-36 PCS/MCS scores in CSM were compared with national normative values and disease-specific norms using Student t test. Analysis of variance was used to assess differences across age groups and offsets from age-matched controls. Threshold for significance was P < 0.05. RESULTS: There were 285 patients who met the inclusion criteria. The mean age was 56.6 ± 12.0 years, with male predominance (60%). SF-36 scores revealed significant baseline disability (PCS: 34.5 ± 9.8; MCS: 41.5 ± 14.4). Although there were no differences across age groups, when compared with age-matched normative data, younger patients had a larger PCS offset than older patients. CSM caused worse physical disability than most diseases except heart failure. Only back pain/sciatica induced worse mental disability. CONCLUSIONS: CSM affects quality of life to an extent greater than diabetes or cancer. Although mean impact of CSM does not vary with age, younger patients suffer from greater differences in baseline function. This study highlights the impact of myelopathy on patient function, particularly among younger age groups, and suggests that CSM merits a similar caliber of healthy policy attention as more well-studied diseases.

Laminectomy and fusion versus laminoplasty for the treatment of degenerative cervical myelopathy: results from the AOSpine North America and International prospective multicenter studies.

BACKGROUND CONTEXT: It remains unclear whether cervical laminoplasty (LP) offers advantages over cervical laminectomy and fusion (LF) in patients undergoing posterior decompression for degenerative cervical myelopathy (DCM). PURPOSE: The objective of this study is to compare outcomes of LP and LF. STUDY DESIGN/SETTING: This is a multicenter international prospective cohort study. PATIENT SAMPLE: A total of 266 surgically treated symptomatic DCM patients undergoing cervical decompression using LP (N=100) or LF (N=166) were included. OUTCOME MEASURES: The outcome measures were the modified Japanese Orthopaedic Association score (mJOA), Nurick grade, Neck Disability Index (NDI), Short-Form 36v2 (SF36v2), length of hospital stay, length of stay in the intensive care unit, treatment complications, and reoperations. METHODS: Differences in outcomes between the LP and LF groups were analyzed by analysis of variance and analysis of covariance. The dependent variable in all analyses was the change score between baseline and 24-month follow-up, and the independent variable was surgical procedure (LP or LF). In the analysis of covariance, outcomes were compared between cohorts while adjusting for gender, age, smoking, number of operative levels, duration of symptoms, geographic region, and baseline scores. RESULTS: There were no differences in age, gender, smoking status, number of operated levels, and baseline Nurick, NDI, and SF36v2 scores between the LP and LF groups. Preoperative mJOA was lower in the LP compared with the LF group (11.52±2.77 and 12.30±2.85, respectively, p=.0297). Patients in both groups showed significant improvements in mJOA, Nurick grade, NDI, and SF36v2 physical and mental health component scores 24 months after surgery (p<.0001). At 24 months, mJOA scores improved by 3.49 (95% confidence interval [CI]: 2.84, 4.13) in the LP group compared with 2.39 (95% CI: 1.91, 2.86) in the LF group (p=.0069). Nurick grades improved by 1.57 (95% CI: 1.23, 1.90) in the LP group and 1.18 (95% CI: 0.92, 1.44) in the LF group (p=.0770). There were no differences between the groups with respect to NDI and SF36v2 outcomes. After adjustment for preoperative characteristics, surgical factors and geographic region, the differences in mJOA between surgical groups were no longer significant. The rate of treatment-related complications in the LF group was 28.31% compared with 21.00% in the LP group (p=.1079). CONCLUSIONS: Both LP and LF are effective at improving clinical disease severity, functional status, and quality of life in patients with DCM. In an unadjusted analysis, patients treated with LP achieved greater improvements on the mJOA at 24-month follow-up than those who received LF; however, these differences were insignificant following adjustment for relevant confounders.

A comparison of computed tomography measures for diagnosing cervical spinal stenosis associated with myelopathy: a case-control study.

STUDY DESIGN: Retrospective comparative study. PURPOSE: To assess differences in computed tomography (CT) imaging parameters between patients with cervical myelopathy and controls. OVERVIEW OF LITERATURE: There is a lack of information regarding the best predictor of symptomatic stenosis based on osseous canal dimensions. We postulate that smaller osseous canal dimensions increase the risk of symptomatic central stenosis. METHODS: CT images and medical records of patients with cervical myelopathy (19 patients, 8 males; average age, 64.4±13.4 years) and controls (18 patients, 14 males; average age, 60.4±11.0 years) were collected. A new measure called the laminar roof pitch angle (=angle between the lamina) was conducted along with linear measures, ratios and surrogates of canal perimeter and area at each level C2-C7 (222 levels). Receiver-operator curves were used to assess the diagnostic value of each. Rater reliability was assessed for the measures. RESULTS: The medial-lateral (ML) diameter (at mid-pedicle level) and calculated canal area (=anterior-posterior.×ML diameters) were the most accurate and highly reliable. ML diameter below 23.5 mm and calculated canal area below 300 mm(2) generated 82% to 84% sensitivity and 67% to 68% sensitivity. No significant correlations were identified between age, height, weight, body mass in dex and gender for each of the CT measures. CONCLUSIONS: CT measures including ML dimensions were most predictive. This study is the first to identify an important role for the ML dimension in cases of slowly progressive compressive myelopathy. A ML reserve may be protective when the canal is progressively compromised in the anterior-posterior dimension.

Quantitative differences in intervertebral disc-matrix composition with age-related degeneration.

This study was carried out to determine the effect of age on the intervertebral disc, using a rabbit model. Anulus fibrosus and nucleus pulposus tissue from New Zealand white rabbits aged 3 years old (old rabbits) and 6 months old (young rabbits) were used. The water content, the proteoglycan, the DNA content, and the mRNA levels of aggrecan, type I collagen, and type II collagen were all measured for each sample. Water, proteoglycan, DNA, and the mRNA levels of aggrecan and type II collagen were all greater in the nucleus pulposus of the young rabbits as compared to the old. For the anulus fibrosus, the difference between young and old is less marked with only proteoglycan and DNA being greater in the young disc as compared to the old. Clearly, according to our results, it is the nucleus pulposus that suffers the brunt of the changes with age.

A comparison of three cell types as potential candidates for intervertebral disc therapy: annulus fibrosus cells, chondrocytes, and bone marrow derived cells.

OBJECTIVES: Candidate cell types for disc cell transplantation therapy include anulus fibrosus (AF) cells, chondrocytes, and bone marrow derived cells (BMDCs). We compared the disc matrix production in these three types of cells, before and after stimulation with rhBMP-2. There is no study extant that compares these three cell types to determine the best candidate for the disc cell therapy. METHODS: AF cells, chondrocytes, and BMDCs (iliac crest and femur) were isolated and grown in monolayer. They were treated for 3 days with rhBMP-2. After 3 days, proteoglycan (sGAG) content in the media was quantified. The results were normalized by cell numbers. The mRNA expression of aggrecan, type I collagen, and type II collagen was measured using real-time PCR. Each cell type was also cultured in chamber slides and immunostained for aggrecan, type I collagen, and type II collagen after 3 days of treatment with rhBMP-2. RESULTS: (1) Without rhBMP-2 the chondrocytes produced more proteoglycan (sGAG) as compared to the other two cell types (AF cells and BMDCs). After stimulation with rhBMP-2 the chondrocytes produce even more proteoglycan than the other two cell types. (2) As compared to the other two cell types, in terms of mRNA expression, the chondrocytes expressed more aggrecan, type I collagen, and type II collagen before stimulation with rhBMP-2. After rhBMP-2 stimulation, the chondrocytes expressed even more aggrecan, type I collagen, and type II collagen in proportion to the concentration of rhBMP-2. For the BMDCs there were no changes in type I and II collagen. (3) rhBMP-2 stimulation produced increases in the protein levels of aggrecan, type I and II collagen in all three types of cells. CONCLUSIONS: On balance, according to these results, it would seem that chondrocytes are the best candidate for the disc cell therapy.

Cervical radiculopathy.

Cervical radiculopathy is a disorder involving dysfunction of cervical nerve roots that commonly manifests as pain radiating from the neck into the distribution of the affected root. Acute cervical radiculopathy generally has a self-limited clinical course, with up to a 75% rate of spontaneous improvement. Thus, nonsurgical treatment is the appropriate initial approach for most patients. When nonsurgical treatment fails to relieve symptoms or if a significant neurologic deficit exists, surgical decompression may be necessary. Surgical outcomes for relief of arm pain range from 80% to 90% with either anterior or posterior approaches.