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Conventional scRNA-seq expression analyses rely on the availability of a high quality genome annotation. Yet, as we show here with scRNA-seq experiments and analyses spanning human, mouse, chicken, mole rat, lemur and sea urchin, genome annotations are often incomplete, in particular for organisms that are not routinely studied. To overcome this hurdle, we created a scRNA-seq analysis routine that recovers biologically relevant transcriptional activity beyond the scope of the best available genome annotation by performing scRNA-seq analysis on any region in the genome for which transcriptional products are detected. Our tool generates a single-cell expression matrix for all transcriptionally active regions (TARs), performs single-cell TAR expression analysis to identify biologically significant TARs, and then annotates TARs using gene homology analysis. This procedure uses single-cell expression analyses as a filter to direct annotation efforts to biologically significant transcripts and thereby uncovers biology to which scRNA-seq would otherwise be in the dark., Conventional single-cell RNA sequencing analysis rely on genome annotations that may be incomplete or inaccurate especially for understudied organisms. Here the authors present a bioinformatic tool that leverages single-cell data to uncover biologically relevant transcripts beyond the best available genome annotation.

Single-cell RNA sequencing is a powerful tool to study developmental biology but does not preserve spatial information about tissue morphology and cellular interactions. Here, we combine single-cell and spatial transcriptomics with algorithms for data integration to study the development of the chicken heart from the early to late four-chambered heart stage. We create a census of the diverse cellular lineages in developing hearts, their spatial organization, and their interactions during development. Spatial mapping of differentiation transitions in cardiac lineages defines transcriptional differences between epithelial and mesenchymal cells within the epicardial lineage. Using spatially resolved expression analysis, we identify anatomically restricted expression programs, including expression of genes implicated in congenital heart disease. Last, we discover a persistent enrichment of the small, secreted peptide, thymosin beta-4, throughout coronary vascular development. Overall, our study identifies an intricate interplay between cellular differentiation and morphogenesis., Using single-cell and spatial transcriptomics in chicken hearts, here, the authors generate a census of cellular interactions from early to late four-chambered heart stage, identifying a distinct epicardial-mesenchymal cell population with a migratory phenotype.

Single-cell RNA sequencing is a powerful tool to study developmental biology but does not preserve spatial information about cellular interactions and tissue morphology. Here, we combined single-cell and spatial transcriptomics with new algorithms for data integration to study the early development of the chicken heart. We collected data from four key ventricular development stages, ranging from the early chamber formation stage to the late four-chambered stage. We created an atlas of the diverse cellular lineages in developing hearts, their spatial organization, and their interactions during development. Spatial mapping of differentiation transitions revealed the intricate interplay between cellular differentiation and morphogenesis in cardiac cellular lineages. Using spatially resolved expression analysis, we identified anatomically restricted gene expression programs. Last, we discovered a stage-dependent role for the small secreted peptide, thymosin beta-4, in the coordination of multi-lineage cellular populations. Overall, our study identifies key stage-specific regulatory programs that govern cardiac development.

The aim was to estimate risk of aortic re-operation, and re-operative morbidity and mortality, following replacement of the proximal aorta for aneurysm or dissection.A meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the Meta-Analysis of Observational Studies in Epidemiology guidelines. A comprehensive literature review was performed to identify all articles reporting aortic re-operation after proximal aortic replacement. The proximal aorta was defined as extending to the origin of the brachiocephalic trunk. The incidence rate for aortic re-operation (IRAR) was calculated, and stratified based on presence/absence of connective tissue disorders, as well as initial surgical indication. Pooled in hospital mortality and post-operative complication rates were estimated.In total, 7821 patients who underwent proximal aortic replacement from 47 studies were included: 8.3% (n = 649) had Marfan syndrome (MS). During a weighted mean follow up of 4.7 ± 0.3 years, 11.5% (n = 903) underwent aortic re-operation. Mean weighted time between initial surgery and re-operation was 5.2 ± 0.2 years. IRAR was 2.4% per person-year (PPY) (confidence interval [CI] 2.1-2.8%). Patients with MFS had a threefold higher IRAR (6.0% PPY, CI 4.1-8.8%) than did patients without a connective tissue disorders (2.3% PPY, CI 1.9-2.7%; p .001). IRAR was 2.5% PPY (CI 2.1-3.0%) after operation for dissection and 1.3% PPY (CI 0.9-2.0%) after operation for aneurysm (p = .004 for subgroup differences). IRAR proximal and distal to the left subclavian artery was 1.2% PPY (CI 1.0-1.5%) and 1.3% PPY (CI 1.1-1.6%), respectively. The pooled in hospital mortality and complication rates after re-operation were 14.31% (CI 11.28-17.99%) and 18.08% (CI 10.54-29.25%), respectively. On meta-regression, initial operation for dissection was the only significant predictor of aortic re-operation (beta = .030, p = .001).Aortic re-operation occurs at a mean rate of 2.4% per person-year in the five years after proximal aortic replacement and is strongly associated with initial operation for dissection.

Background Totally endoscopic coronary artery bypass (TECAB) has emerged as an alternative to other minimally invasive techniques. However, limited TECAB results are available to date. The purpose of this systematic review is to examine the existing literature to give an objective estimate of the outcomes of TECAB using a meta-analytical approach. Methods A comprehensive online review was performed in Ovid MEDLINE®, Ovid EMBASE and The Cochrane Library from 2000 to July 2017. Eligible studies included single arm TECAB studies as well as comparative studies (TECAB vs minimally invasive direct coronary artery bypass (MIDCAB)). Pooled event rates and odds ratios (ORs) for operative mortality, perioperative myocardial infarction (MI), perioperative stroke, graft patency and repeat revascularization were estimated. Single arm and pairwise comparisons were performed. Results Seventeen single arm TECAB articles (3721 patients, weighted mean follow-up 3.3years) were included. The pooled event rate was 0.80% (95%CI: 0.60–1.2%) for operative mortality, 2.28% (95%CI: 1.7–3%) for perioperative MI, 1.50% (95%CI: 1.1–2.0%) for perioperative stroke, 2.99% (95%CI: 1.6–5.4%) for repeat revascularization and 94.8% (95%CI: 89.3–97.5%) for early graft patency (weighted mean follow-up 10.1months). On pairwise meta-analysis 376 patients (263 TECAB and 113 MIDCAB) were included. No difference in operative mortality (OR=0.25, 95%CI: 0.02–2.83), perioperative MI (OR=3.09, 95%CI: 0.37–26.12) or perioperative stroke (OR=1.33, 95%CI: 0.17–10.26) was found between the two techniques. Conclusions TECAB has an acceptably low operative risk and a good early patency rate. The incidence of perioperative MI requires further investigation. The dearth of data comparing TECAB to open approaches compels the need for future comparative trials.

α2-Macroglobulin (A2M) is a plasma glycoprotein best known for its ability to inhibit a broad spectrum of serine, threonine, and metalloproteases as well as inflammatory cytokines by a unique bait-and-trap method. A2M has emerged as a unique potential treatment of cartilage-based pathology and inflammatory arthritides. This article describes the unique method by which A2M not only inhibits the associated inflammatory cascade but also disrupts the catabolic process of cartilage degeneration. Autologous concentrated A2M from plasma is currently in use to successfully treat various painful arthritides. Future directions will focus on recombinant variants that enhance its anti-inflammatory and disease-modifying potential.

Alpha-2-macroglobulin (A2M) is a major plasma glycoprotein best known for its ability to inhibit a broad spectrum of inflammatory mediators, such as metalloproteases and inflammatory cytokines by a unique “bait-and-trap” method. A2M has emerged as a unique potential treatment for cartilage-based pathology and inflammatory arthritides. A2M can be concentrated from an autologous source and injected into diseased tissue to enhance healing, prevent further degradation, and protect normal tissue. A2M not only inhibits the associated inflammatory cascade, but also disrupts the catabolic process of cartilage degeneration. Any pathology that is protease-mediated may benefit from A2M therapy. The half-life is quite long, so successful treatment can result in months of pain relief. Autologous concentrated A2M from plasma is currently used successfully to treat various painful arthritides, including mild to moderate osteoarthritis, post-traumatic osteoarthritis, enthesopathies, and spinal discogenic pain. Recent work has shown that recombinant A2M may be able to enhance cartilage regeneration. The discovery of A2M as the body’s own healing mechanism, with anti-inflammatory and disease-modifying potential, offers great promise.

Background The study was performed to evaluate whether targeted alpha-2-macroglobulin (A2M) variants have a similar or enhanced function at wild-type (wt)-A2M to attenuate cartilage degeneration in vivo. Methods In and ex-vivo experiment, bovine cartilage explants (BCE) were incubated with TNF-α and IL-1β with or without wt-A2M or A2M variants. Cartilage catabolism was measured in culture supernatant by sulfated glycosaminoglycan (sGAG). In an in-vivo experiment, 2-month-old male Wistar rats (n = 77) were randomly divided into seven groups and treated with different doses of A2M or its variants by intra-articular injection at 24 hours and day 14 after anterior cruciate ligament transection (ACLT), receiving (1) ACLT/PBS; (2) ACLT/wt-A2M (0.153 mg); (3) ACLT/CYT-108 A2M (0.153 mg); (4) ACLT/CYT-108 A2M (0.077 mg); (5) ACLT/CYT-98 A2M (0.153 mg); (6) ACLT/CYT-98 A2M (0.077 mg); or (7) sham/PBS. The joints and synovial lavage were collected 8 weeks after surgery. Fluorescence molecular tomography was used to monitor inflammation in vivo using probes ProSense and MMPSense at 24 hours, and weeks 2, 4, and 6 after surgery. The cartilage damage was quantified using Osteoarthritis Research Society International score and matrix metalloproteinase (MMP)-3, -13, collagen (Col) X, Col 2, Runx2, and aggrecan (Acan) were detected by immunohistochemical analysis (IHC), ELISA, and RT-PCR. Results A2M variants inhibited catabolism in the BCE model by up to 200% compared with wt-A2M. ProSense and MMPSense were dramatically increased in all groups after surgery. Supplemental A2M or its variants reduced ProSense and MMPSense compared with the PBS treatment. Less cartilage damage, lower MMP-13 and Col 2 degraded product, and stronger Col 2 synthesis were detected in animals treated with A2M or its variants compared with PBS-treated animals. A2M and its variants enhanced Col 2 and Acan synthesis, and suppressed MMP-3, MMP-13, Runx2, and Col X production. A2M-108 variant demonstrated less cartilage damage compared with wt-A2M and A2M-98 variant. Conclusion The targeted variants of A2M have a chondroprotective effect similar to wt-A2M. However, A2M-108 variant has enhanced function to attenuate cartilage degeneration compared with wt-A2M.

Ischemic heart disease remains one of the most prominent causes of mortalities worldwide with heart transplantation being the gold-standard treatment option. However, due to the major limitations associated with heart transplants, such as an inadequate supply and heart rejection, there remains a significant clinical need for a viable cardiac regenerative therapy to restore native myocardial function. Over the course of the previous several decades, researchers have made prominent advances in the field of cardiac regeneration with the creation of in vitro human pluripotent stem cell-derived cardiomyocyte tissue engineered constructs. However, these engineered constructs exhibit a functionally immature, disorganized, fetal-like phenotype that is not equivalent physiologically to native adult cardiac tissue. Due to this major limitation, many recent studies have investigated approaches to improve pluripotent stem cell-derived cardiomyocyte maturation to close this large functionality gap between engineered and native cardiac tissue. This review integrates the natural developmental mechanisms of cardiomyocyte structural and functional maturation. The variety of ways researchers have attempted to improve cardiomyocyte maturation in vitro by mimicking natural development, known as natural engineering, is readily discussed. The main focus of this review involves the synergistic role of electrical and mechanical stimulation, extracellular matrix interactions, and non-cardiomyocyte interactions in facilitating cardiomyocyte maturation. Overall, even with these current natural engineering approaches, pluripotent stem cell-derived cardiomyocytes within three-dimensional engineered heart tissue still remain mostly within the early to late fetal stages of cardiomyocyte maturity. Therefore, although the end goal is to achieve adult phenotypic maturity, more emphasis must be placed on elucidating how the in vivo fetal microenvironment drives cardiomyocyte maturation. This information can then be utilized to develop natural engineering approaches that can emulate this fetal microenvironment and thus make prominent progress in pluripotent stem cell-derived maturity toward a more clinically relevant model for cardiac regeneration.

To report hip synovial fluid cytokine concentrations in hips with and without radiographic arthritis. Patients with no arthritis (Tonnis grade 0) and patients with Tonnis grade 2 or greater hip osteoarthritis (OA) were identified from patients undergoing either hip arthroscopy or arthroplasty. Synovial fluid was collected at the time of portal establishment for those undergoing hip arthroscopy and prior to arthrotomy for the arthroplasty group. Analytes included fibronectin–aggrecan complex (FAC) as well as a standard 12 cytokine array. Variables recorded were Tonnis grade, centre-edge angle of Wiberg, as well as labrum and cartilage pathology for the hip arthroscopy cohort. A priori power analysis was conducted, and a Mann–Whitney U test and regression analyses were used with an alpha value of 0.05 set as significant. Thirty-four patients were included (17 arthroplasty, 17 arthroscopy). FAC was the only analyte to show a significant difference between those with and without OA (p

Objective To determine the presence of a fibronectin-aggrecan complex (FAC) in the disk space of persons with chronic low back pain as relates to provocative diskography. Design A single-center prospective consecutive case series. Setting A single private practice setting. Patients Thirty-seven patients with symptomatic degenerative disk disease of the cervical, thoracic, or lumbar spine undergoing provocative diskography to identify a source of pain. Methods Diskographic lavage for analysis was simultaneously performed at each disk level injected during diskography. Main Outcome Measures Visual analog scale (VAS) pain scores, Pfirrmann magnetic resonance imaging grade, and biochemical analysis of disk material were statistically analyzed. Results A total of 105 levels in 37 patients had a complete set of data (mean age 43.2 ± 11.9 years; 15 male/22 female). The FAC was present in 43 of 108 levels and in at least one level in 25 of 37 patients. The Pfirrmann magnetic resonance imaging grade did not differ between complex-positive and negative levels ( P = .125), nor did the intraoperative VAS (IO-VAS) score for pain by level ( P = .206). A significant but loose correlation was found between Pfirrmann grade and IO-VAS ( R 2 = 0.4, P R 2 = 0.08, P = .11 and R 2 = 0.003, P = .5). Conclusions The FAC was identified in some painful disks by diskography. There was no significant correlation between the Pfirrmann grade or pre/intraoperative pain scores during diskography and complex concentrations within the disk measured by disk lavage.

To determine the presence of infectious microorganisms in the herniated discs of immunocompetent patients, using methodology that we hoped would be of higher sensitivity and specificity than has been reported in the past. Recent studies have demonstrated a significant rate of positive cultures for low virulent organisms in excised HNP samples (range 19–53%). These studies have served as the theoretical basis for a pilot trial, and then, a well done prospective randomized trial that demonstrated that systemic treatment with antibiotics may yield lasting improvements in a subset of patients with axial back pain. Whether the reported positive cultures in discectomy specimens represent true positives is as yet not proven, and critically important if underlying the basis of therapeutic approaches for chronic low back pain. This consecutive case series from a single academic center included 44 patients with radiculopathy and MRI findings of lumbar HNP. Patients elected for lumbar microdiscectomy after failure of conservative management. All patients received primary surgery at a single spinal level in the absence of immune compromise. Excised disc material was analyzed with a real-time PCR assay targeting the 16S ribosomal RNA gene followed by amplicon sequencing. No concurrent cultures were performed. Inclusion criteria were as follows: sensory or motor symptoms in a single lumbar nerve distribution; positive physical examination findings including positive straight leg raise test, distributional weakness, and/or a diminished deep tendon reflexes; and magnetic resonance imaging of the lumbar spine positive for HNP in a distribution correlating with the radicular complaint. The PCR assay for the 16S rRNA sequence was negative in all 44 patients (100%). 95% CI 0–8%. Based on the data presented here, there does not appear to be a significant underlying rate of bacterial disc infection in immunocompetent patients presenting with radiculopathy from disc herniation.

While the effect of local anaesthetics on chondrocyte viability is widely documented, the effect of these medications on synoviocytes is largely unknown. The purpose of this study was to understand the effect of 0.5 % bupivacaine and 0.5 % bupivacaine with epinephrine on synoviocyte viability, cytokine and growth factor release, and breakdown product formation. Rabbit fibroblast-like synoviocyte (Type B) cultures were perfused with 0.5 % bupivacaine or 0.5 % bupivacaine with epinephrine (1:200,000) for 24 h. Cell viability was evaluated using a two-colour fluorescence assay. The supernatant was analysed using multiplex inflammatory and matrix metalloproteinase assays. Synoviocytes treated for 24 h with 0.5 % bupivacaine with epinephrine demonstrated a significant decrease in viability (31.3 ± 19.4 % cell death) when compared with synoviocytes cultured in control media (3.8 ± 1.3 % cell death, p = 0.000) and those cultured in 0.5 % bupivacaine alone (12.6 ± 11.1 % cell death, p = 0.003). No significant decrease in cell viability was observed in synoviocytes treated with 0.5 % bupivacaine compared to those in control media (12.6 ± 11.1 % vs 3.8 ± 1.3 % cell death, p = 0.194). Significantly greater amounts of MMP-1 (47.0 ± 9.2 pg/ml) and MMP-3 (250.0 ± 68.8 pg/ml) were observed in 0.5 % bupivacaine cultures compared with controls (14.3 ± 14.3, p = 0.023 and 72.0 ± 84.9, p = 0.045, respectively). 0.5 % bupivacaine with epinephrine caused a significant increase in cell death of the synoviocytes, while 0.5 % bupivacaine alone produced cell injury and a significant release of matrix metalloproteinases, which may also lead to indirect injury of the surrounding chondrocytes. These results may help explain the onset of chondrolysis observed in patients who have been treated with intra-articular local anaesthetics.

A single-center, prospective, consecutive case series of patients undergoing epidural lavage before the treatment of radiculopathy due to lumbar disc herniation.To determine whether a novel complex of fibronectin and aggrecan predicts clinical response to epidural steroid injection (ESI) for the indication of radiculopathy from lumbar herniated nucleus pulposus (HNP).ESI for lumbar radiculopathy due to HNP is widely used despite variable effectiveness for this indication. With increased attention aimed at cost containment, it would be beneficial to identify those in whom ESI may be helpful. There are currently no accurate diagnostic tests to predict response to ESI in back pain and sciatica syndromes. We have previously investigated biomarkers of disc degeneration associated with radiculopathy.We embarked to determine whether a molecular complex of fibronectin and aggrecan predicts clinical response to ESI for the indication of radiculopathy from HNP. This prospective study was conducted at a single center and included 26 patients with radiculopathic pain and magnetic resonance imaging positive for HNP, who elected ESI. Epidural lavage with physiologic saline was performed immediately before ESI. The lavage fluid was assayed for the fibronectin-aggrecan complex (FAC) by using a heterogeneous sandwich enzyme-linked immunosorbent assay. The results were compared with the interval improvement in the physical component summary (PCS) score of the Medical Outcomes Study Short Form-36 instrument (SF-36) after injection compared with baseline.The mean improvement from baseline PCS in patients with the FAC was 22.9 (SD, 12.4) and without the complex was 0.64 (SD, 3.97; P0.001). Differences in total SF-36 improvement were also highly significant (P0.001). The presence of the FAC predicts a clinically significant increase in PCS after lumbar ESI by receiver-operating-characteristic analysis (area under the curve = 0.97; P0.001). There was no significant difference in age (P = 0.25), sex (P = 0.84), laterality (P = 0.06), lumbar spinal level (P = 0.75), or payer type (worker's compensation vs. private insurance; P = 0.90) between groups with and without the marker.A molecular complex of fibronectin and aggrecan predicts response to lumbar ESI for radiculopathy with HNP. The biomarker is accurate, objective, and not affected by demographic or psychosocial variables in this series.

Background Context The commercially available growth factor recombinant bone morphogenic protein-2 (rhBMP-2) used in spinal fusion has been associated with numerous adverse reactions, including inflammatory reactions in soft tissue, heterotopic bone formation, radiculitis, osteolysis, and cage or graft subsidence. The original Food and Drug Administration Summary of anterior lumbar interbody fusion (ALIF) reported 12 retrograde ejaculation (RE) events (8%) in the rhBMP-2 groups compared with (1.4%) in the control group. It had been debated whether this finding was related to rhBMP-2 use. Purpose To compare the incidence of RE after ALIF in patients with and without rhBMP-2 use. Study design Retrospective analysis of prospectively gathered outcomes data on consecutive subjects having ALIF with and without rhBMP-2 use. Patient sample Male patients with lumbar spondylosis or spondylolisthesis having ALIF of the lowest one or two lumbar levels with and without rhBMP-2. Outcome measure Report of RE as a new finding after ALIF. Methods From the comprehensive outcome database at a high-volume university practice, male subjects having ALIF for one- (L5/S1) or two-level (L4/L5, L5/S1) lumbar fusion were identified. Retrograde ejaculation events were recorded and comparative incidence compared. Results The two groups were comparable for age and additional procedures performed. There were 69 L5/S1 ALIFs performed with rhBMP-2 and 174 ALIFs performed without rhBMP-2 during the study period. Of those, 24 and 64 were two-level ALIFs performed with and without rhBMP-2, respectively. There were five RE events (7.2%) reported in the rhBMP-2 group and 1 (0.6%) in the control group. Comparing single-level L5/S1 ALIF, there was a 6.7% and 0% rate of RE in the rhBMP-2 versus control groups, respectively. At 1 year after surgery, three of six affected subjects reported resolution of the RE. Conclusion This study confirms previous reports of a higher rate of RE in ALIF procedures using rhBMP-2. This may be an important consideration in subjects concerned with sterility after surgery.

A case-control study with prospectively collected samples for laboratory analysis in a series of patients with spinal fragility fractures and a series of patients without fracture who underwent fusion for LBP.Was an exploratory data analysis for candidate cytokine biomarkers present in the fracture milieu of patients with persistent back pain associated with vertebral compression fracture.Lumbar and thoracic compression fractures are common. Little is known about the presence of inflammatory mediators within fractured vertebra in the clinical setting.Thirty patients diagnosed with a single thoracic or lumbar compression fracture were treated with single level vertebroplasty. At the time of intervention, needle aspiration was carried out at the fractured level. A multiplexed bead assay was used to assess the presence of 27 different cytokines and inflammatory mediators. A control group consisted of needle aspiration samples of 30 lumbar vertebra from 13 patients with chronic pain but no fracture undergoing open instrumented fusion.Thirty patients with 30 fractures consisted of 23 female and 7 male with a mean age of 77.5 years (SD 13.6; range 42 to 97) and a mean of 3.9 weeks of pain (SD 3.1; range 1 to 12). The highest levels of inflammatory mediators were (in order): IL-1 receptor antagonist, PDGF, RANTES, IP-10, IL-8, and eotaxin. These mediators were present at concentrations200 pg/mL. Compared with controls with chronic pain, significant differences were present for 4 mediators: TNF, MIP-1b, IL-9, and IL-12. The panel of these 4 markers was 93.3% specific and 66.7% sensitive for fracture compared with the control group.Inflammatory mediators are present in needle aspirates of symptomatic vertebral compression fractures. Some of these mediators show different levels than in patients with chronic pain but no fracture.Diagnostic level of evidence II.

Background context The use of antiplatelet agents after coronary artery stent placement is currently recommended to prevent coronary stent obstruction. These patients may have concurrent disabling spinal stenosis and require spinal decompression. Resuming antiplatelet agents as soon as possible after spinal surgery is recommended. Purpose To describe a unique case of late postoperative epidural hematoma occurring with the use of clopidogrel. Study design A case report and review of the literature. Methods The hospital chart, history, physical examination, and imaging of a single patient were reviewed. Results A 59-year-old man underwent spinal decompression and fusion for neurogenic claudication with lumbar spinal stenosis and spondylolisthesis while managed on clopidogrel for prevention of thrombosis after cardiac stent placement. He developed a symptomatic epidural hematoma 12 days postoperatively, well outside the usual time frame for this complication. The patient was closely monitored, and lumbar radiculopathy resolved over the ensuing days. Conclusion After spinal surgery and resumption of antiplatelet therapy, the physician needs to maintain vigilance in observing patients for late postoperative complications such as epidural hematoma, which could have catastrophic consequences if not recognized in a timely manner.

STUDY DESIGN Observational cohort study. SUMMARY OF BACKGROUND DATA Studies evaluating the treatment of presumed discogenic spine pain using nucleoplasty have reported variable success rates. It has been suggested that these procedures lower the intradiscal pressure, reduce disk protrusion, improve disk hydration, and restore disk height. It is proposed that such structural changes in treated disks correspond to the clinical improvement in patients. Radiographic and clinical evidence showing the efficacy of nucleoplasty remains inadequate. OBJECTIVE To document the comparative changes in magnetic resonance imaging (MRI) the appearance of disk morphology as reflected by Pfirrmann classification scores before and after the nucleoplasty treatment in patients with continued symptoms. METHODS Twenty-eight consecutive patients with persistent symptoms after nucleoplasty within 1 year of treatment were evaluated. Prenucleoplasty and postnucleoplasty MRIs were evaluated and Pfirrmann scores of the symptomatic level were determined. RESULTS In all the treated patients, comparison between the prenucleoplasty and the postnucleoplasty MRI of the targeted disks failed to show increased signal hydration, disk space height improvement, or shrinkage of the preoperative disk bulge at a mean time of 6 months after the procedure. Of the 17 cervical levels treated in 12 patients, 5 seemed to show progressive degeneration at treated levels (42% of the patients). Of the 17 lumbar procedures in 16 patients, 4 seemed to show progressive degeneration (25% of the patients) and 1 developed a new spondylolisthesis (6.3%). Thus, 32% of the patients in our cohort showed progressive degeneration at the treated level. The median Pfirrmann score in both prenucleoplasty and postnucleoplasty was 2, and the mean Pfirrmann classification prenucleoplasty and postnucleoplasty was 1.8 and 2.1, respectively (P

Background context The pathophysiology underlying degenerative disc disease and its implication in painful syndromes remain unclear. However, spine magnetic resonance imaging (MRI) can demonstrate changes in disc water content and the annulus; provocative discography purportedly identifies degenerate discs causing serious low back pain; and biochemical assays have identified local inflammatory markers. No study to date has correlated pain on disc injection during discography evaluation with relevant MRI findings and biochemical markers. Purpose The purpose of this study was to correlate concordant pain on during discography to biochemical markers obtained by disc lavage and MRI findings. Study design This is a Phase 1 Diagnostic Test Assessment Cohort Study (Sackett and Haynes). Patient sample The patient sample included 21 symptomatic patients with suspected discogenic pain and three Phase 1 control subjects. Outcome measures The outcome measures included discography pain scores, MRI degenerative grades, and immunoreactivity to various inflammatory cytokine concentrations present in disc lavage samples. Methods Twenty-one symptomatic patients with lumbar degenerative disc disease and three control subjects underwent discography, MRI, and biochemical analysis of disc lavage fluid. Lumbar MRI was scored for Pfirrmann grading of the lumbar discs, and annular disruption was identified by nuclear disc lavage. Disc lavage samples were analyzed for biochemical markers by high-sensitivity immunoassay. Results Eighty-three discs from 24 patients were studied: 67 discs from 21 patients with axial back pain (suspected discogenic pain group) and 16 discs from 3 scoliosis patients without back pain (Phase 1 control subjects). Among the biochemical markers surveyed, interferon gamma (IFN-γ) immunoreactivity was most consistently identified in patients with axial back pain. Discs with annular disruption and concordant pain reproduction at a visual analog scale of 7 to 10/10 had greater IFN-γ immunoreactivity than those without this finding (p=.003); however, at least some IFN-γ immunoreactivity was found in all but one disc in the symptomatic group. Conclusions Among the potential inflammatory markers tested in this Phase 1 study, IFN-γ immunoreactivity was most commonly elevated in discogram “positive” discs but absent in asymptomatic controls. However, this marker was also frequently elevated in degenerative but “negative” discography discs. From these findings, Phase 2 and Phase 3 validity studies are reasonable to pursue. Phase 4 utility studies may be performed concurrently to assess this method's predictive value in outcome studies.

Pseudomorbidity in iliac crest bone graft harvesting: the rise of rhBMP-2 in short-segment posterior lumbar fusion Eugene J. Carragee, MD*, Christopher M. Bono, MD, Gaetano J. Scuderi, MD Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA Orthopedic Spine Service, Brigham and Women’s Hospital, Boston, MA 02478, USA Department of Orthopaedic Surgery, Stanford University Hospital and Clinics, Stanford, CA 94305, USA Received 1 September 2009; accepted 9 September 2009

STUDY DESIGN: The study is a prospective observational study of 48 continuous patients with symptomatic lumbar degenerative disk disease. Each patient underwent discography, MRI, and a biochemical analysis of disk lavage fluid. OBJECTIVES: The purpose of this study was to correlate concordant pain on discography with MRI grade and biochemical markers of inflammation in a clinical setting. SUMMARY OF BACKGROUND DATA: The pathophysiology of degenerative disk disease is complex. Discography is used to differentiate symptomatic from asymptomatic levels. MRI is used to image changes in disk water content. Biochemical assays have identified molecular markers of inflammation. To date, no study has correlated concordant pain on discography with MRI findings and biochemical markers. METHODS: Forty-eight (48) continuous patients with symptomatic lumbar degenerative disk disease gave informed consent for study entry. Patient sex, age, insurance, work status and visual analog score (VAS) were recorded. MRI was obtained and Pfirrmann grading was performed by a single spine surgeon. Discography with disc lavage was performed by a single anesthesiologist. Lavage samples were tested for inflammatory markers with high resolution multi-plex bead immunoassays and ELISA with O5 pg/ml resolution. RESULTS: None of demographic variables was significantly related to concordant pain on discogram by chi-squared tests and Mann-Whitney U-test. The Pfirrmann score was significantly different for patients with and without concordant pain at L3-L4 (p!0.001), but was insignificant at other levels after multitest correction. Pfirrmann scores were significantly different at any level in patients with and without concordant pain. VAS scores were not significantly correlated with opening pressures at any level. Despite the presence of serum proteins in the disk lavage fluid, none of the tested inflammatory mediators was identified by multi-plex bead immunoassays and ELISA. CONCLUSIONS: There are only weak correlations between demographic, discogram, and radiographic variables. Response to discogram cannot be predicted by non-invasive means. The disk lavage method was unable to identify the presence of specific inflammatory peptides with multiplex immunoassays and ELISA. 2008 Elsevier Inc. All rights reserved.

We report a case of a survivor of occipito-atlantal dislocation with atlantoaxial subluxation, an injury which is frequently fatal. Children less than 11 years of age appear to be especially vulnerable to these injuries due to their anatomy. The mechanism is alluded to but poorly understood. The literature review highlights the difficulty in confirming dislocation and subluxation based on the metrics of anatomic landmarks.

Cost containment and surgical inefficiencies are major concerns for hospitals in this era of declining resources. The primary aim of this investigation was to understand subjective perceptions of perioperative spine surgical quality across three practice settings and to identify potential factors contributing to these perceptions. Subsequently, we objectively evaluated factors that influence the duration of time in which the patient is in the operating room (OR) prior to the surgical incision and assessed the influence of fluoroscopy technician expertise on radiation dose and imaging efficiency.One hundred and eight medical device representatives with at least 1 year of OR experience were surveyed at a national conference. Three distinct healthcare facilities were identified: university, small volume, and large volume private hospitals. Respondents rated facilities on a five-point scale for staff quality; size and consistency of surgical teams; and overall likelihood of recommending the facility. Separately, 140 posterior lumbar procedures from two institutions were retrospectively reviewed. Two time periods were quantified for each surgical case: patient arrival in the OR to induction of anesthesia (T1) and induction to surgical incision (T2). T1 and T2 were compared between university and large private hospital settings using t tests and multivariate analysis. For 44 separate lumbar spine surgical procedures, practice setting, patient BMI, number of vertebral levels requiring imaging, number of localizing fluoroscopy images taken, total fluoroscopy time, total radiation dose, fluoroscopy machine, and whether the fluoroscopist could correctly state his or her role, which was to obtain a lateral lumbar localizing image, were recorded. T-tests were used to compare cases in which the fluoroscopist could and could not correctly state the task.Survey ratings for surgeons were not significantly different across university, large private, and small private hospitals. Fewer circulating nurses were rated as excellent or good in university versus private hospitals (p0.001). Small volume private hospital surgical teams were more likely to have worked together before than university teams (p0.05), and university teams were larger (p0.05). Respondents were more likely to recommend a university or large private hospital for complex instrumentation cases (p0.001). On objective measures, university patients were older, less obese, and had higher mean ASA scores (2.5 versus 2.2, p0.001). Compared to the university setting, private hospital cases had significantly shorter Time 1 (8 versus 37 min, p0.001) and Time 2 (23 versus 30 min, p0.001), even after adjusting for ASA score, BMI, and age. Cases in which the fluoroscopist knew the imaging purpose were associated with significantly fewer images (mean 1.8 versus 3.4 images, p0.0001) and shorter total exposure times (2.3 versus 4.0 sec, p0.001). Operations performed in the university setting were associated with significantly more images (2.7 versus 1.8 images, p0.001), longer total exposure times (3.2 versus 2.3 sec, p = 0.0027), and total radiation dose (27.8 versus 53.3 rad, p0.001) when compared with those performed in the private setting. The university practice setting was associated with significantly more images (2.7 versus 1.8 images, p0.001), longer total exposure times (3.2 versus 2.3 sec, p = 0.003), and total radiation dose (27.8 versus 53.3 rad, p0.001) when compared with non-university settings.Large private and university hospitals had higher surgeon ratings. The university setting was associated with larger and less consistent surgical teams and lower nurse ratings. Surgical staff awareness of the procedure and attention to preoperative tasks specific to the procedure reduced pre-operative time spent in the OR as well as fluoroscopy radiation. These data suggest that nurses and support staff make substantial contributions to overall quality of care, and that leadership and interpersonal coordination are especially important within large teams at teaching hospitals.

Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin-aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson's correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy.

Background context Traditionally, lead-based garments are the standard method of intraoperative radiation protection during fluoroscopy. Unfortunately, the lead used is heavy, lacks durability, is difficult to launder, and its disposal is associated with environmental hazards. Purpose An evaluation of the protective radiation efficiency of three commercially available radiation protective garments compared with a standardized lead protective shield. Study design/setting Measured radiation transmission through lead and three commercially available lightweight radiological protective garments (Xenolite, EarthSafe, and Demron) was performed using a standard, calibrated dosimeter. Methods Radiation transmission, attenuation, lead equivalencies as well as garment weight comparisons were measured. The tests were repeated through a range of voltage and tube current settings that are common to clinical radiological applications (60–120 keV). Results All materials tested demonstrated effectiveness at common clinically relevant energy exposures (100 keV). EarthSafe and Xenolite demonstrated 0.5 mm lead equivalency protection at 80 and 100 keV X-ray energies but not at higher energy levels (>100 keV), which is where most radiological procedures are performed utilizing more advanced technological imaging equipment. Demron was best able to effectively shield ionizing radiation at higher energy levels (>100 keV). The lightweight nature of these lead-free materials may result in less fatigue and musculoskeletal complaints by the wearer. Conclusions Of the tested lead-free garments, Demron appears to offer equivalent levels of protection to standard lead-based shields within traditional energy zones but with less weight than standard lead-based shields.

Introduction Lumbar disk herniation may result in a radiculopathic pattern of symptoms. Consideration for a primary biochemical inducement of pain over a mechanical mechanism is a contemporary topic of spinal research. However, the exact pathomechanism by which a degenerative intervertebral disk leads to neural inflammation and pain has not been determined. Using modern techniques of chemical analysis, biochemical markers can be identified which participate in the degenerative cascade, and possibly with the onset of pain. The purpose of this research is to identify potential biochemical markers through a novel technique of epidural space lavage that may be helpful in understanding the pathogeneses of pain in the presence of intervertebral disk degeneration and herniation. Methods Fifty consecutive patients with acute radiculopathy secondary to a symptomatic herniated lumbar intervertebral disk or spinal stenosis, and who were indicated for epidural steroid injection were identified. Additionally, 3 volunteers with no history of back pain or radiculopathy volunteered to undergo epidural lavage. After needle insertion, a lavage followed by fluid aspiration of the epidural space at the level of the disc herniation, in the case of the symptomatic patients, was performed using normal saline, before the instillation of corticosteroids. The fluid samples were frozen at -20 degrees C until analysis. A biochemical evaluation for a battery of cytokines was undertaken (IL-1beta, IL-1ra, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p40, IL-13, IL-15, IL-17, TNF-alpha, IFN-alpha, IFN-gamma, GM-CSF, MIP-1alpha, MIP-1beta, IP-10, MIG, Eotaxin, RANTES, and MCP-1, and neuropeptides) using high-resolution multiplex bead immunoassays and enzyme-linked immunosorbent assay (ELISA). Additionally, polyacrylamide gel electrophoresis was carried out to verify the presence of serum proteins. Results Despite the presence of amino acids/serum proteins in the epidural lavage fluid, none of the aforementioned mediators were isolated in a quantifiable concentration using the ELISA techniques with >5 pg/mL resolution. Discussion The current proteomics array technology was not able to detect critical levels of biochemical markers present in the epidural space through the mentioned lavage technique. This lack of detection could be due to the absence of the factors in this environment or the inability of the technique to obtain or detect factors which may be present. Conclusion Although a novel approach, the current study was unable to identify the presence of a series of inflammatory peptides in the epidural lavage of patients with symptomatic radicular pain due to herniated disc disease. We recommend alternative experimental designs than the one we pursued for definitively identifying potential sources of pain generators.

Background: Pedicle screw instrumentation is common in the lumbar spine and is gaining acceptance in the thoracic spine. The pedicle is generally cannulated with a gearshift probe or curette. SafePath (Mekanika, Boca Raton, FL) is an alternative pedicle probe designed for pedicle cannulation. This is a blunt-tipped, nonaggressive drill that seeks the cancellous portion of the pedicle. Objective: The objective of this study was to evaluate the accuracy of this device in comparison with techniques commonly used for pedicle cannulation. Methods: Four osteoligamentous fresh-frozen thoracic to sacral cadaveric spines were studied. The pedicles of one side of each cadaver were cannulated with the SafePath device. The contralateral pedicles were cannulated with either a gearshift probe or a 3-0 cervical curette. The accuracy of pedicle probe placement was evaluated by radiography, computed tomography (CT) scan, and direct observation via dissection. Results: By direct observation, 51 of 128 pedicles were violated (40%). There were not significant differences between the results obtained with the gearshift probe or curette; there were 2 of 22 lumbosacral violations (9%) and 14 of 45 thoracic violations (33%). With the SafePath device, there were 0 of 22 lumbosacral violations (0%) and 34 of 45 thoracic violations (76%). SafePath performed significantly better in the lumbar spine and significantly worse in the thoracic spine. The accuracy for determining pedicle violation was 88% for radiography and 85% for CT. Conclusions: The results of this in vitro study suggest that the SafePath device may represent an alternative to traditional pedicle cannulation techniques in the lumbosacral spine. However, the opposite is true in the thoracic spine, where SafePath performed significantly worse than traditional techniques.

STUDY DESIGN: Animal study. OBJECTIVE: Development of an animal model for the study of biochemical changes that occur in the epidural space after intervertebral disc herniation. SUMMARY OF BACKGROUND DATA: Although strong evidence for an inflammatory component exists, the biochemical processes underlying pain after disc herniation remain unknown. METHODS: Epidural lavage was performed in 48 rats after L5 dorsal root ganglion exposure at baseline and 3, 6, or 24 hours after placement of autologous nucleus pulposus (NP) (N = 15), saline (N = 15), or NP + an interferon-γ antibody (anti-IFN-γ; N = 18) directly onto the dorsal root ganglion. Multiplex assays quantifying interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor α (TNF-α), IFN-γ, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were performed. NP (N = 7) was also analyzed for these cytokines by placing NP into saline and measuring the relative concentration. RESULTS: Cytokines measured low at baseline (0-100 pg/mL) in all groups. Compared with saline, NP application caused IL-6 elevation, peaking at T = 3 hours, that was prevented by anti-IFN-γ. NP induced elevation of TNF-α, peaking at T = 24 hours and was prevented by anti-IFN-γ. IFN-γ was elevated after NP at T = 3 hours and T = 24 hours. IL-1α was similar after saline versus NP. The concentrations of IL-1β and IL-10 were elevated at T = 3 hours, 6 hours, and 24 hours in all groups without between-groups difference. The level of IL-4 peaked at T = 3 hours in the NP group and was different than saline and NP + anti-IFN-γ groups, but the time effect was insignificant. There was no change for GM-CSF. The concentration of cytokines measured in normal NP was less than 2 pg/mL for all cytokines except TNF-α. CONCLUSION: In this model of acute noncompressive disc herniation, NP caused the elevation of epidural IL-6, TNF-α, and IFN-γ--all attenuated by IFN-γ blockade. IL-1β and IL-10 were both significantly elevated by saline alone and their response was not prevented by IFN-γ blockade. This model may prove useful for the study of the biochemical processes by which NP induces inflammation-induced nerve root irritation and radiculopathic pain.

Background: The effect of platelet-rich plasma on chondrocytes has been studied in cell and tissue culture. Less attention has been given to the effect of platelet-rich plasma on nonchondrocytic cell lineages within synovial joints, such as fibroblast-like synoviocytes, which produce cytokines and matrix metalloproteinases (MMPs) that mediate cartilage catabolism. The purpose of the present study was to determine the effect of platelet-rich plasma on cytokines and proteases produced by fibroblast-like synoviocytes. Methods: Platelet-rich plasma and platelet-poor plasma from harvested autologous blood were prepared with a commercially available system. Fibroblast-like synoviocytes were treated with platelet-rich plasma, platelet-poor plasma, recombinant PDGFbb (platelet-derived growth factor bb), or phosphate-buffered saline solution and incubated at 37! Cf or forty-eight hours. The concentrations of IL-1b (interleukin-1b), IL-1RA (IL-1 receptor antagonist), IL-6, IFN-g (interferon-g), IP-10 (interferon gamma-induced protein 10), MCP-1 (monocyte chemotactic protein-1), MIP-1b (macrophage inflammatory protein-1b), PDGFbb ,R ANTES, TNF-a (tumor necrosis factor-a), VEGF (vascular endothelial growth factor), MMP-1, MMP-3, and MMP-9 in the culture medium were determined by multiplex immunoassay. Results: Platelet-rich plasma cultured in medium contained multiple catabolic mediators in substantial concentrations, including MMP-9 (15.8 ± 2.3 ng/mL) and MMP-1 (2.5 ± 0.8 ng/mL), as well as proinflammatory mediators IL-1b, IL-6, IFN-g, IP-10, MCP-1, MIP-1b ,R ANTES, and TNF-a in concentrations between 20 pg/mL and 20 ng/mL. Plateletpoor plasma contained significantly lower concentrations of these compounds. Platelet-rich plasma was used to treat humanfibroblast-likesynoviocytes,andtheresulting concentrationsof mediatorswerecorrectedfortheconcentrations in the platelet-rich plasma alone. Compared with untreated fibroblast-like synoviocytes, synoviocytes treated with platelet-rich plasma exhibited significantly greater levels of MMP-1 (363 ± 94.0 ng/mL, p = 0.018) and MMP-3 (278 ± 90.0 ng/mL, p = 0.018). In contrast, platelet-poor plasma had little effect on mediators secreted by the synoviocytes. PDGFbb-treated fibroblast-like synoviocytes exhibited a broad proinflammatory cytokine response at four and forty-eight hours. Conclusions: Platelet-rich plasma was shown to contain a mixture of anabolic and catabolic mediators. Synoviocytes treated with platelet-rich plasma responded with substantial MMP secretion, which may increase cartilage catabolism. Synoviocytes responded to PDGF with a substantial proinflammatory response. Clinical Relevance: Themultiplecatabolicmediatorsinplatelet-richplasmaandthesecretionofMMPsbyfibroblast-like synoviocytes treated with platelet-rich plasma could potentially accelerate cartilage catabolism, and this warrants further investigation.

Study Design This study analyzed the precise two-dimensional location of the vertebral artery within cervical vertebrae as determined by measurements obtained from axial computed tomogaphic images of the cervical spine. Objective to determine the margin of safety necessary to avoid vertebral artery laceration during central decompression and lateral nerve root decompression for cervical spinal stenosis. Summary of Background Data Laceration of the vertebral artery is a rare but potentially catastrophic complication of anterior decompressive surgery of the cervical spine. Methods The mean, standard deviation, and 95% confidence interval of the mean of measurements localizing the vertebral artery within the vertebral body were calculated from 50 transaxial computed tomography images of each of the second through sixth cervical vertebrae. Results Bothe the mean interforminal distance (from 25.90% ± 1.89 mm at C3 to 29.30 ± 2.70 mm at C6) and the average distance of the posterior border of the foramen transversarium from the ventral border of the spinal canal (from 2.16 ± 1.18 mm at C3 to 3.53 ± to 3.53 ± 1.56 mm at C6) increased from C3 to C6. Conclusions According to our measurements, the risk of vertebral artery laceration is greater at more cephalad vertebrae during lateral extension of central decompressive procedures and lateral nerve root decompression. Because of the variability of these parameters between individuals, accurate individual preoperative localization of the vertebral arteries is recommended.

Acute calcific retropharyngeal tendinitis is an underrecognized cause of pain and stiffness in the neck associated with odynophagia and retropharyngeal soft-tissue swelling. We report on five patients in whom an initial misdiagnosis of this entity as a retropharyngeal or nasopharyngeal abscess, a neoplasm, or a fracture-dislocation of the cervical spine led to interventions such as admission to the hospital and parenteral administration of antibiotics. An open biopsy was performed in one patient because of a suspected neoplasm. Evaluation of the tissue specimen with routine and polarized light microscopy, scanning electron microscopy, and energy-dispersive spectrometry demonstrated a foreign-body inflammatory response to deposited crystals of hydroxyapatite. In all five patients, the correct diagnosis was established only after retrospective review of the radiographic studies by a physician who was familiar with acute calcific retropharyngeal tendinitis. The computed tomographic findings of acute calcific retropharyngeal tendinitis are distinctive and consist of prevertebral calcification localized to the insertion of an edematous tendon of the longus colli muscle. Symptomatic relief was provided with anti-inflammatory and analgesic medications. The symptoms resolved, without sequelae, within one to two weeks for all of the patients. We hope that an increased awareness of hydroxyapatite deposition in the tendon of the longus colli muscle will result in improved early diagnosis of acute calcific retropharyngeal tendinitis.

Background: Molecular biomarkers associated with knee pain may be useful as diagnostic modalities, prognostic indicators, and surrogate end points for therapeutic trials. The present study describes a novel complex of fibronectin and aggrecan that is present in the affected knee of patients with pain and meniscal abnormality. Methods: The present prospective study included thirty patients with knee pain, mechanical symptoms, and magnetic resonance imaging findings that were positive for a meniscal tear who chose arthroscopic partial meniscectomy after unsuccessful nonoperative management. Synovial fluid was aspirated at the time of surgery and was assayed for the fibronectin-aggrecan complex with use of a heterogeneous enzyme-linked immunosorbent assay (ELISA). The results were compared with knee aspirates from ten asymptomatic volunteers with no pain who underwent magnetic resonance imaging of the knee. Results: The mean optical density (and standard deviation) of the fibronectin-aggrecan complex was significantly greater in synovial fluid from knees undergoing arthroscopic surgery as compared with fluid from asymptomatic controls (13.29 ± 8.48 compared with 0.03 ± 0.09; p < 0.001). The mean age in the study group was significantly greater than in control group (46.0 ± 12.6 compared with 38.5 ± 6.0 years; p = 0.02), but controlling for age did not affect the results. Post hoc, an optical density cutoff value of 0.3 distinguished the study group from the control group with 100% accuracy. Conclusions: A novel fibronectin-aggrecan complex is present in the synovial fluid of painful knees with meniscal abnormality. The fibronectin-aggrecan complex may prove to be useful as a clinical biomarker or therapeutic target. Further research is warranted to correlate functional outcome after surgery with the fibronectin-aggrecan complex and other cartilage biomarkers. Level of Evidence: Diagnostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

Objective To investigate the presence of inflammatory cytokines and the fibronectin-aggrecan complex (FAC) in persons undergoing surgical treatment for cervical radiculopathy caused by disk herniation. Design Single-center, prospective, consecutive case series. Setting A single large academic institution. Patients A total of 11 patients with radiculopathic pain and magnetic resonance imaging findings positive for disk herniation elected to undergo single-level cervical diskectomy. Methods or Interventions Lavage was performed by needle injection and aspiration upon entering the disk space for fluoroscopic localization before diskectomy. Main Outcome Measurements The lavage fluid was assayed for pH and the FAC, as well as for the cytokines interleukin-6 (IL-6), interferon-γ, monocyte chemotactic protein (MCP), and macrophage inhibitory protein-1β. Results The subjects were 7 women and 4 men with a mean age of 50.6 years (SE 9.7; range, 36-70 years). The mean concentrations (SE; range) in picograms per milliliter were 7.9 (4.4; 0-44) for IL-6, 25.3 (15.5; 0-159) for interferon-γ, 16.1 (11.9; 0-121) for MCP, and 6.1 (2.8; 0-29) for macrophage inhibitory protein-1β. The optical density of the FAC at 450 nm was 0.151 (0.036; 0.1-0.32), and the pH was 6.68 (0.1; 6.10-7.15). Statistically significant correlations were found between MCP and FAC ( P = .036) and between FAC and pH ( P = .008). Conclusions Biochemical analysis of injured cervical intervertebral disks reveals the presence of inflammatory markers such as MCP, fragments of structural matrix proteins such as FAC, and a correlation with pH. Further evaluation of the FAC as a potential diagnostic biomarker or therapeutic target is warranted in the cervical spine.

article Objectives: We previously described a panel of four cytokines biomarkers in knee synovial fluid for acute knee pain associated with meniscal pathology. The cytokine biomarkers included interferon gamma (IFN-γ), interleukin 6 (IL-6), monocyte chemotactic protein 1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1β). Validation studies using other immunologic techniques confirmed the presence of IL-6, MCP-1 and MIP-1β, but not IFN-γ. Therefore we sought the identity of the IFN-γ signal in synovial fluid. Methods: Knee synovial fluid was collected from patients with an acute, painful meniscal injury, as well as asymptomatic volunteers. A combination of high-pressure chromatography, mass spectrometry and immunological techniques were used to enrich and identify the protein components representing the IFN-γ signal. Results: A protein complex of fibronectin and the aggrecan G3 domain was identified in the synovial fluid of patients with a meniscal tear and pain that was absent in asymptomatic controls. This protein complex correlated to the IFN-γ signal. A novel enzyme-linked immunosorbent assay (ELISA) was developed to specifically identify the complex in synovial fluid. Conclusions: We have identified a protein complex of fibronectin and aggrecan G3 domain that is a candidate biomarker for pain associated with meniscal injury.

Study design Prospective observational cohort. Objective Correlate epidural inflammatory cytokines with the clinical response to epidural steroid injection in patients with lumbar nerve root irritation. Summary of background data Some back pain syndromes are thought to be associated with activation of inflammatory pathways and others may be associated with primary mechanical derangements. Human studies providing detailed evidence for the primary inflammatory causation, which may be best treated with anti-inflammatory strategies, are lacking. There are currently no accurate diagnostic tests to predict the response to epidural steroid injection or surgical intervention in back pain and sciatica syndromes. METHODS.: Forty-seven consecutive patients with lumbar degenerative changes and low back and/or leg pain were prospectively enrolled. An epidural lavage was performed, followed by injection of marcaine/depo-medrol. Subjects scored their pain before and 3 months after the procedure. The immunoreactivity of an array of cytokines was measured in lavage samples and compared with clinical response to the therapeutic injection. Ten subjects underwent repeat epidural lavage sampling 3 months after the steroid injection. Results Interferon gamma (IFNgamma) was the most consistently detected cytokine. IFNgamma-immunoreactivity also highly correlated with reported reduction of pain 3-months after the epidural steroid injection. In subjects reporting significant pain relief (>50%) from the injection, mean [IFNgamma] was significantly greater compared with patients experiencing no significant relief. The IFNgamma-immunoreactivity in repeat lavage samples decreased to trace residual concentrations in patients who reported pain relief from the steroid injection. Conclusion The presence of epidural IFNgamma-immunoreactivity corresponding to >10 pg/mL predicted significant pain relief after epidural steroid injection with >95% accuracy. These results suggest that IFNgamma may be part of a biochemical cascade triggering pain in sciatica; IFNgamma-immunoreactivity may aid as a biomarker for predicting the response to steroid therapy and/or surgical intervention, and may serve as a future therapeutic target.

The diagnosis of clinically important meniscal tears of the knee remains challenging, and it is unknown why only some injuries become painful. The role of inflammatory cytokines in generating pain following meniscal injury remains unclear. This study aimed to investigate the cytokine profile in patients with acute knee pain believed to be secondary to meniscal damage.This prospective cohort study included thirty-two patients without rheumatoid arthritis who had knee pain for less than six months, with either an acute or insidious onset, and elected to have arthroscopic treatment after nonoperative management had failed. Twenty-three of these patients elected to have the contralateral, nonoperatively treated knee lavaged at the time of arthroscopy. Fifteen asymptomatic control subjects also contributed samples of knee joint fluid, for a total of seventy samples from forty-seven subjects. Lavage of the operatively treated, contralateral, and control knees was performed with the patient under regional anesthesia prior to arthroscopy, if applicable, by the infusion of sterile saline solution into the knee followed by the immediate withdrawal into a syringe. The concentrations of seventeen inflammatory cytokines and chemokines were measured with use of a multiplexed immunoassay panel. Preoperative magnetic resonance imaging findings and cytokine assay results were compared with intraoperative findings.Multivariate analysis of variance detected significantly greater concentrations of interferon gamma (IFN-gamma); interleukins 2, 4, 6, 10, and 13 (IL-2, IL-4, IL-6, IL-10, and IL-13); monocyte chemotactic protein-1 (MCP-1); and macrophage inflammatory protein-1 beta (MIP-1beta) in fluid samples from painful knees than in samples from nonpainful knees. Correlation analysis demonstrated a significant positive correlation between patient-reported pain scores and concentrations of IL-6 (Spearman rho = 0.7), MCP-1 (rho = 0.8), MIP-1beta (rho = 0.6), and IFN-gamma (rho = 0.6). These four cytokines also demonstrated a positive correlation with each other (rho = 0.5 to 0.7). The presence of IFN-gamma, IL-6, MCP-1, or MIP-1beta performed as well as magnetic resonance imaging in the prediction of intraoperative findings.Intra-articular concentrations of four inflammatory cytokines IFN-gamma, IL-6, MCP-1, and MIP-1beta correlated to pain in patients with symptomatic meniscal tears in the knee but were markedly lower in asymptomatic normal knees and in asymptomatic knees with meniscal tears. These cytokines may be involved in the generation of pain following meniscal injury.

Purpose To evaluate the presence and relative concentrations of cytokines, known to be involved in the inflammatory cascade, in acute anterior cruciate ligament (ACL) injury. Methods We evaluated an extensive cytokine profile in synovial fluid from 12 patients with acute ACL injury undergoing arthroscopy compared with 15 control subjects using a BioPlex assay (Bio-Rad Laboratories, Hercules, CA) to measure the concentration of 17 inflammatory cytokines. Results In patients with acute ACL injury compared with asymptomatic control subjects, the following cytokines were identified at significantly increased concentrations ( P U test) compared with control samples: interleukin 6 (105 ± 72 v 0 ± 0 pg/ml), interferon γ (1,544 ± 608 v 9 ± 7.5 pg/ml), macrophage inflammatory protein 1β (16 ± 3.8 v 0.3 ± 0.2 pg/ml), and monocyte chemotactic protein 1 (35 ± 13 v 0.5 ± 0.4 pg/ml). There was no case of a cytokine exhibiting increased levels in asymptomatic compared with symptomatic knee samples. Conclusions This investigation identified 4 specific cytokines (interleukin 6, interferon γ, monocyte chemotactic protein 1, and macrophage inflammatory protein 1β) out of a panel of 17 inflammatory molecules for which the levels were consistently elevated in the context of ACL injury compared with non-painful, non–acutely injured knees in a volunteer population. Level of Evidence Level IV, prognostic case series.

Patients experiencing subacute low back pain (LBP) represent a challenge for the physical therapist. There have been few studies on the use of continuous passive motion of the lumbar spine for the treatment of LBP. Three patients with symptoms of subacute LBP without radiculopathy were treated using a novel device for continuous passive motion of the lumbar spine. The protocol consisted of 12 sessions of lumbar continuous passive motion at 30 minutes per session two to three times per week for 4 to 5 weeks. Outcomes were assessed at baseline and after 12 sessions at 4 to 5 weeks by Oswestry score and active range of motion measurements by a blinded investigator. Clinically significant improvements in Oswestry score and consistent improvements in range were observed. A supervised protocol using a commercial device can benefit some patients with subacute LBP if supervised by a knowledgeable practitioner.

The cases of three patients with a history of paralytic poliomyelitis in childhood who developed the flat back syndrome before or after spinal fusion for degenerative disease as adults were reviewed. The flat back syndrome, a combination of an inability to stand erect because of forward flexion of the trunk and pain in the low back and/or legs, typically occurs in the setting of decreased lumbar lordosis as a result of distraction instrumentation of the spine for scoliosis, vertebral fracture, or degenerative disease. Focus was placed on determining the factors responsible for the development and/or persistence of the flat back syndrome in these patients despite maintenance of, or partial operative restoration of, lumbar lordosis. Considering the essential role that the trunk extensor musculature plays in maintaining upright posture, it may be that a new onset of weakness (postpolio syndrome) in this musculature represents a major contributing factor to the flat back syndrome in these patients. Spine surgeons considering operative procedures in patients with a remote history of paralytic poliomyelitis should be aware of the possible increased risk of the flat back syndrome in this population of patients.

Vertebral osteomyelitis is a difficult problem in the spinal cord injured patient. We present three such cases treated with extensive debridement followed by grafting and stabilization with external fixation. In all three patients the infection resolved. We feel this is a viable option for treating this condition.

Background context Patients with approved workers' compensation injuries receive guaranteed compensation for the duration of their injury, whereas patients with personal injury claims are only compensated, if at all, at the time of a successful settlement or trial verdict at a time point distant from their injury. Purpose This study compares the financial impact and loss of work patterns due to a workers' compensation (WC) claim or personal injury in patients with a symptomatic cervical disc herniation resulting from a motor vehicle collision. Study design A prospective study of patients who were seen by a single spine specialist between 1/2/96 and 9/1/01. Patient sample A consecutive evaluation of 531 patients who were treated for a cervical pain syndrome caused by a motor vehicle collision. Outcome measures Mechanism of injury and insurance type, ie, workers' compensation or personal injury, was recorded for each patient as well as treatment response and return to work patterns. The data were analyzed using the two-way Z test. Methods All patients were managed in a similar manner with noninvasive treatment initially, followed by injections, and finally surgical intervention in those who failed conservative measures. Return to work rates and work disability were determined at either final follow-up or at the last doctor's visit before loss to follow-up. Results 270 of 531 patients were diagnosed with a symptomatic one or two level disc herniation by a cervical magnetic resonance imaging scan. Fifty-four patients were insured through the workers' compensation board, and 216 reported their crash as a personal injury claim. In the WC group the work disability at 3 months follow-up revealed a cumulative 2,262 total lost days of work (average 37.1 days per person). At the point of maximal medical improvement (MMI) or 2-year follow-up, total days lost from work were 7,107 (average 131.6 days per person.) In the personal injury non-WC group, the 3-month follow-up of lost days of work was 1,093 days (average 5.1 days per person.) At 2 years follow-up, the total lost days of work were 6,206 (average 28.7 days per person.) Conclusions Participants compensated through the workers' compensation system demonstrated a significant loss of days of work as compared with injured patients who received compensation by other means. This may be a reflection of the guaranteed method of compensation afforded to WC patients as opposed to patients who receive no form of financial support (ie, personal injury) during the recuperative process. Further analysis as to injury severity and a stratification of non-workers' compensation reimbursement methods are needed to further improve the validity of this study.

Nerve root anomalies are frequently underrecognized on advanced imaging studies and may account for some percentage of failed spinal surgical procedures. The conjoined nerve root represents the most common nerve root anomaly. It is a well-known cause of false-positive readings for bulging and herniated disks in patients with purely axial neuroimaging studies. A retrospective evaluation of consecutive microsurgical lumbar diskectomies in 80 patients during a 5-year period was undertaken. A total of four patients (5%) were found intraoperatively to have evidence of a conjoined nerve root by the classification of Neidre. None was diagnosed preoperatively. Coronal magnetic resonance imaging offers the best means of visualizing a conjoined nerve root. The chance for a successful operation can be significantly enhanced if the surgeon is prepared to encounter this pathology.

A retrospective review of 12 patients who were victims of penetrating trauma with a bullet or bullet fragments lodged within the intervertebral disk space was conducted. The objective of the review was to evaluate the potential systemic effects of lead resorption at long-term follow-up. Literature regarding the potential for lead toxicity due to retained bullet fragments within the intervertebral disk space is lacking. Between January 1969 and June 1993, a total of 238 patients with a gunshot wound to the spine were identified. Twelve of the 238 were found to have a bullet or bullet fragments within the intervertebral disk space. All patients were fully screened for evidence of plumbism. The average age at time of gunshot injury was 35.8 years; the average time for follow-up was 7.8 years. One of the 12 patients showed clinical evidence of plumbism. The patient subsequently underwent a partial laminectomy and diskectomy with excision of the bullet fragments. The patient's complaints, specific for plumbism, resolved 2 months postoperatively. We conclude that patients with retained lead-based bullet fragments in the intervertebral disk should be educated about the rare potential for plumbism due to partial bullet fragment resorption and that long-term observation for this disorder is recommended.