MR Neurography and Quantitative Muscle MRI of Parsonage Turner Syndrome Involving the Long Thoracic Nerve.

BACKGROUND: Parsonage-Turner syndrome (PTS) is characterized by severe, acute upper extremity pain and subsequent paresis and most commonly involves the long thoracic nerve (LTN). While MR neurography (MRN) can detect LTN hourglass-like constrictions (HGCs), quantitative muscle MRI (qMRI) can quantify serratus anterior muscle (SAM) neurogenic changes. PURPOSE/HYPOTHESIS: 1) To characterize qMRI findings in LTN-involved PTS. 2) To investigate associations between qMRI and clinical assessments of HGCs/electromyography (EMG). STUDY TYPE: Prospective. POPULATION: 30 PTS subjects (25 M/5 F, mean/range age = 39/15-67 years) with LTN involvement who underwent bilateral chest wall qMRI and unilateral brachial plexus MRN. FIELD STRENGTH/SEQUENCES: 3.0 Tesla/multiecho spin-echo T2-mapping, diffusion-weighted echo-planar-imaging, multiecho gradient echo. ASSESSMENT: qMRI was performed to obtain T2, muscle diameter fat fraction (FF), and cross-sectional area of the SAM. Clinical reports of MRN and EMG were obtained; from MRN, the number of HGCs; from EMG, SAM measurements of motor unit recruitment levels, fibrillations, and positive sharp waves. qMRI/MRN were performed within 90 days of EMG. EMG was performed on average 185 days from symptom onset (all ≥2 weeks from symptom onset) and 5 days preceding MRI. STATISTICAL TESTS: Paired t-tests were used to compare qMRI measures in the affected SAM versus the contralateral, unaffected side (P < 0.05 deemed statistically significant). Kendall's tau was used to determine associations between qMRI against HGCs and EMG. RESULTS: Relative to the unaffected SAM, the affected SAM had increased T2 (50.42 ± 6.62 vs. 39.09 ± 4.23 msec) and FF (8.45 ± 9.69 vs. 4.03% ± 1.97%), and decreased muscle diameter (74.26 ± 21.54 vs. 88.73 ± 17.61 µm) and cross-sectional area (9.21 ± 3.75 vs. 16.77 ± 6.40 mm2 ). There were weak to negligible associations (tau = -0.229 to <0.001, P = 0.054-1.00) between individual qMRI biomarkers and clinical assessments of HGCs and EMG. DATA CONCLUSION: qMRI changes in the SAM were observed in subjects with PTS involving the LTN. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Hourglass-like constrictions on MRI are common in electromyography-confirmed cases of neuralgic amyotrophy (Parsonage-Turner syndrome): A tertiary referral center experience.

INTRODUCTION/AIMS: Hourglass-like constrictions (HGCs) of involved nerves in neuralgic amyotrophy (NA) (Parsonage-Turner syndrome) have been increasingly recognized with magnetic resonance neurography (MRN). This study sought to determine the sensitivity of HGCs, detected by MRN, among electromyography (EMG)-confirmed NA cases. METHODS: This study retrospectively reviewed records of patients with the clinical diagnosis of NA, and with EMG confirmation, who underwent 3-Tesla MRN within 90 days of EMG at a single tertiary referral center between 2011 and 2021. "Severe NA" positive cases were defined by a clinical diagnosis and specific EMG criteria: fibrillation potentials or positive sharp waves, along with motor unit recruitment (MUR) grades of "discrete" or "none." On MRN, one or more HGCs, defined as focally decreased nerve caliber or diffusely beaded appearance, was considered "imaging-positive." Post hoc inter-rater reliability for HGCs was measured by comparing the original MRN report against subsequent blinded interpretation by a second radiologist. RESULTS: A total of 123 NA patients with 3-Tesla MRN performed within 90 days of EMG were identified. HGCs were observed in 90.2% of all NA patients. In "severe NA" cases, based on the above EMG criteria, HGC detection resulted in a sensitivity of 91.9%. Nerve-by-nerve analysis (183 nerve-muscle pairs, nerves assessed by MRN, muscles assessed by EMG) showed a sensitivity of 91.0%. The second radiologist largely agreed with the original HGC evaluation, (94.3% by subjects, 91.8% by nerves), with no significant difference between evaluations (subjects: χ2 = 2.27, P = .132, nerves: χ2 = 0.98, P = .323). DISCUSSION: MRN detection of HGCs is common in NA.

Parsonage-Turner syndrome following monkeypox infection and vaccination.

Beginning in May 2022, monkeypox infection and vaccination rates dramatically increased due to a worldwide outbreak. This case highlights magnetic resonance (MR) neurography findings in an individual who developed Parsonage-Turner syndrome (PTS) 5 days after monkeypox symptom onset and 12 days after receiving the JYNNEOS vaccination. MR neurography of the patient's left suprascapular nerve demonstrated intrinsic hourglass-like constrictions, a characteristic finding of peripheral nerves involved in PTS. Other viral infections and vaccinations are well-documented triggers of PTS, an underrecognized peripheral neuropathy that is thought to be immune-mediated and results in severe upper extremity pain and weakness. The close temporal relationship between monkeypox infection and vaccination, and PTS onset, in this case, suggests a causal relationship and marks the first known report of peripheral neuropathy associated with monkeypox.

Quantitative MRI Differentiates Electromyography Severity Grades of Denervated Muscle in Neuropathy of the Brachial Plexus.

BACKGROUND: Quantitative MRI (qMRI) metrics reflect microstructural skeletal muscle changes secondary to denervation and may correspond to conventional electromyography (EMG) assessments of motor unit recruitment (MUR) and denervation. HYPOTHESIS: Differences in quantitative T2 , diffusion-based apparent fiber diameter (AFD), and fat fraction (FF) exist between EMG grades, in patients with clinically suspected neuropathy of the brachial plexus. STUDY TYPE: Prospective. POPULATION: A total of 30 subjects (age = 37.5 ± 17.5, 21M/9F) with suspected brachial plexopathy. FIELD STRENGTH/SEQUENCE: 3-Tesla; qMRI using fast spin echo (T2 -mapping), multi-b-valued diffusion-weighted echo planar imaging (for AFD), and dual-echo Dixon gradient echo (FF-mapping) sequences. ASSESSMENT: qMRI values were compared against EMG grades (MUR and denervation). qMRI values (T2 , AFD, and FF) were obtained for five regional shoulder muscles. A 4-point scale was used for MUR/denervation severity. STATISTICAL TESTS: Linear mixed models and least-squares pairwise comparisons were used to evaluate qMRI differences between EMG grades. Predictive accuracy of EMG grades from qMRI was quantified by 10-fold cross-validated logistic models. A P value < 0.05 was considered statistically significant. RESULTS: Mean (95% confidence interval) qMRI for "full" MUR were T2  = 39.40 msec (35.72-43.08 msec), AFD = 78.35 µm (72.52-84.19 µm), and FF = 4.54% (2.11-6.97%). Significant T2 increases (+8.36 to +14.67 msec) and significant AFD decreases (-11.04 to -21.58 µm) were observed with all abnormal MUR grades as compared to "full" MUR. Significant changes in both T2 and AFD were observed with increased denervation (+9.59 to +15.04 msec, -16.25 to -18.66 µm). There were significant differences in FF between some MUR grades (-1.45 to +2.96%), but no significant changes were observed with denervation (P = 0.089-0.662). qMRI prediction of abnormal MUR or denervation was strong (mean accuracy = 0.841 and 0.810, respectively) but moderate at predicting individual grades (accuracy = 0.492 and 0.508, respectively). DATA CONCLUSION: Quantitative T2 and AFD differences were observed between EMG grades in assessing muscle denervation. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Parsonage-Turner Syndrome Following COVID-19 Vaccination: MR Neurography.

Vaccination is one of the several known triggers of Parsonage-Turner syndrome (PTS). This case series describes two individuals with clinical presentations of PTS whose symptoms began 13 hours and 18 days following receipt of the Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273 COVID-19 vaccine, respectively. The diagnosis of PTS was confirmed by using both electrodiagnostic testing and 3.0-T MR neurography. Although research is needed to understand the association between PTS and COVID-19 vaccination, MR neurography may be used to help confirm suspected cases of PTS as COVID-19 vaccines continue to be distributed worldwide.

Ultrasound-guided percutaneous needle tenotomy (PNT) alone versus PNT plus platelet-rich plasma injection for the treatment of chronic tendinosis: A randomized controlled trial.

BACKGROUND: Tendinosis is a chronic degenerative condition. Current research suggests both percutaneous needle tenotomy (PNT) and leukocyte-rich platelet-rich plasma (LR-PRP) may be effective treatments for chronic tendinosis, but no studies have assessed the effectiveness of PNT alone versus PNT with intratendinous LR-PRP for multiple tendon types in a single study. OBJECTIVE: To assess the efficacy of PNT versus PNT + LR-PRP to treat chronic tendinosis. STUDY DESIGN: Double-blind, randomized, controlled comparative treatment study. SETTING: Primary academic institution. PARTICIPANTS: A convenience sample of 40 participants who had chronic tendinosis (rotator cuff, wrist extensor, wrist flexor, hip abductor, proximal hamstring, patellar, or Achilles) confirmed via ultrasound, failed conservative treatment, and did not have tendon tears, known coagulopathy, or systemic illnesses. INTERVENTIONS: Participants were randomly assigned to PNT (n = 19) or PNT + LR-PRP (n = 21). Participants and outcomes assessors were blinded to treatment assignments. PNT was performed with 20-30 passes of a 22-gauge needle under ultrasound guidance, with 1% lidocaine given outside the tendon. LR-PRP was processed from whole blood (30-60 mL) and injected into the affected tendon using the same PNT technique. MAIN OUTCOME MEASURES: Primary outcome was current numerical rating scale pain at 6 weeks. Secondary outcomes were average pain, function, general well-being, and sleep quality at 6, 52, and 104 weeks. RESULTS: Baseline characteristics were similar between groups. Overall, there were no significant differences between groups over time for any of the outcomes (P > .05). Between-group analyses showed significantly lower current and average pain after PNT compared to PNT + LR-PRP at 6 weeks (estimated-mean [SE]: 3.1[0.4] vs. 4.6[0.6], P = .04; 3.4[0.4] vs. 4.9[0.5], P = .03) only. Adverse event rates were low (PNT-3.9%; PNT + LR-PRP-5.0%) and related primarily to postprocedural pain and inflammation. CONCLUSIONS: Although pain scores were lower after PNT compared to PNT + LR-PRP at 6 weeks, there were no between-group differences in outcomes at 52 or 104 weeks.

Advanced Concepts in Hip Morphology, Associated Pathologies, and Specific Rehabilitation for Athletic Hip Injuries.

Hip and groin injuries comprise up to 17% of athletic injuries and can pose rehabilitation challenges for many athletes. Injuries involving abnormal femoral acetabular morphology, reduced range of motion, and decreased lumbopelvic strength and endurance also may increase the risk of injury to lower extremities and delay return to play if proper rehabilitation does not take place. The rehabilitation of athletic hip injuries requires a multifaceted interdisciplinary approach that manages the interplay of multiple factors to restore preinjury function and facilitate return to play. Emphasis should be placed on activity modification, preservation of the arcs of range of motion, functional strengthening of the lumbopelvic core, and optimization of proprioceptive and neuromechanical strategies. Communication between providers and the injured athlete also is crucial to ensure that proper therapeutic approaches are being applied.

Proximal Linear Extension of Skin Hypopigmentation After Ultrasound-Guided Corticosteroid Injection for de Quervain Tenosynovitis: A Case Presentation.

de Quervain tenosynovitis is a stenosing tenosynovitis of the first dorsal compartment of the wrist that can lead to painful functional impairment of the upper limb. This case presentation describes a rare adverse effect of corticosteroid injection (CSI) involving local skin atrophy and hypopigmentation with proximal linear extension. In this case, hypopigmentation developed from the wrist to beyond the elbow after CSI with ultrasound guidance and targeted placement of the injectate in the extensor tendon sheath of the first dorsal compartment. Dermal complications of CSI are rare but notable and potentially disfiguring events that should be discussed with every patient during the informed consent process before soft tissue CSIs. LEVEL OF EVIDENCE: V.

Associations of Race and Ethnicity With Patient-Reported Outcomes and Health Care Utilization Among Older Adults Initiating a New Episode of Care for Back Pain.

STUDY DESIGN: Secondary analysis of the Back Pain Outcomes using Longitudinal Data (BOLD) cohort study. OBJECTIVE: To characterize associations of self-reported race/ethnicity with back pain (BP) patient-reported outcomes (PROs) and health care utilization among older adults with a new episode of care for BP. SUMMARY OF BACKGROUND DATA: No prior longitudinal studies have characterized associations between multiple race/ethnicity groups, and BP-related PROs and health care utilization in the United States. METHODS: This study included 5117 participants ≥65 years from three US health care systems. The primary BP-related PROs were BP intensity and back-related functional limitations over 24 months. Health care utilization measures included common diagnostic tests and treatments related to BP (spine imaging, spine-related relative value units [RVUs], and total RVUs) over 24 months. Analyses were adjusted for multiple potential confounders including sociodemographics, clinical characteristics, and study site. RESULTS: Baseline BP ratings were significantly higher for blacks vs. whites (5.8 vs. 5.0; P < 0.001). Participants in all race/ethnicity groups showed statistically significant, but modest improvements in BP over 24 months. Blacks and Hispanics did not have statistically significant improvement in BP-related functional limitations over time, unlike whites, Asians, and non-Hispanics; however, the magnitude of differences in improvement between groups was small. Blacks had less spine-related health care utilization over 24 months than whites (spine-related RVU ratio of means 0.66, 95% confidence interval [CI] 0.51-0.86). Hispanics had less spine-related health care utilization than non-Hispanics (spine-related RVU ratio of means 0.60; 95% CI 0.40-0.90). CONCLUSION: Blacks and Hispanics had slightly less improvement in BP-related functional limitations over time, and less spine-related health care utilization, as compared to whites and non-Hispanics, respectively. Residual confounding may explain some of the association between race/ethnicity and health outcomes. Further studies are needed to understand the factors underlying these differences and which differences reflect disparities. LEVEL OF EVIDENCE: 3.

Running Injuries During Adolescence and Childhood.

The popularity of running among young athletes has significantly increased over the past few decades. As the number of children who participate in running increases, so do the potential number of injuries to this group. Proper care of these athletes includes a thorough understanding of the unique physiology of the skeletally immature athlete and common injuries in this age group. Treatment should focus on athlete education, modification of training schedule, and correction of biomechanical deficits contributing to injury. Early identification and correction of these factors will allow a safe return to running sports.

Comparison between different radiographic methods for evaluating the flexibility of scoliosis curves.

OBJECTIVE: To compare different radiographic methods of spine evaluation to estimate the reducibility and flexibility of the scoliosis curves. METHODS: Twenty one patients with Lenke types I and III adolescent idiopathic scoliosis (AIS) were included. Radiographic evaluations were made preoperatively on the orthostatic, supine decubitus with lateral inclination to the right and left and supine positions with manual reduction, with support in the apex of each curve on the X-ray table. On the day of surgery, when the patient was anesthetized, radiography was taken with longitudinal traction through divergent forces, holding under the arms and ankles, and with translational force at the apex of the deformity for curve correction. After one week, a post-operative radiography was performed in orthostatic position. RESULTS: The correction and flexibility of the main thoracic and thoracic/lumbar curves were statistically different between the supine radiographs, manual reduction, modified traction under general anesthesia, lateral inclination and postoperatively. The modified maneuver for traction under general anesthesia is the one which showed greater flexibility, besides presenting higher radiographic similarity to postoperative aspects. CONCLUSION: Among the radiographic modalities evaluated the study under anesthesia with traction and reduction showed better correlation with postoperative radiographic appearance. Level of Evidence IV, Case Series.

Radiographic and functional evaluation of the iliac bone graft in the treatment of adolescent idiopathic scoliosis.

This study aimed to assess the impact of the use of an additional iliac bone graft on functional and radiographic results after thoracic spine arthrodesis with pedicle screws in patients with adolescent idiopathic scoliosis. Participants were divided into two groups: a control group that received only local bone (n=19) and a second group that, in addition to this procedure, received an iliac graft (n=22). The evaluations were performed on preoperative, immediate postoperative, and last follow-up (mean 29.7 months; minimum 12 months). Radiographic evaluations included the loss of correction and the presence of nonunion. The functional outcome was evaluated using the Scoliosis Research Society-30 questionnaire. Surgical complications and the presence of iliac donor site pain were also described. There were no significant differences between groups in the pseudoarthrosis rate, loss of correction over time, and quality of life. We concluded that the addition of bone graft from the iliac yielded no benefit in terms of the fusion rate and functional outcomes. The appropriate facetectomy, bed preparation, and filling with a local bone graft must be adequate to achieve an adequate fusion on surgical treatment of adolescent idiopathic scoliosis.

Comparison between different radiographic methods for evaluating the flexibility of scoliosis curves

OBJECTIVE: To compare different radiographic methods of spine evaluation to estimate the reducibility and flexibility of the scoliosis curves. METHODS: Twenty one patients with Lenke types I and III adolescent idiopathic scoliosis (AIS) were included. Radiographic evaluations were made preoperatively on the orthostatic, supine decubitus with lateral inclination to the right and left and supine positions with manual reduction, with support in the apex of each curve on the X-ray table. On the day of surgery, when the patient was anesthetized, radiography was taken with longitudinal traction through divergent forces, holding under the arms and ankles, and with translational force at the apex of the deformity for curve correction. After one week, a post-operative radiography was performed in orthostatic position. RESULTS: The correction and flexibility of the main thoracic and thoracic/lumbar curves were statistically different between the supine radiographs, manual reduction, modified traction under general anesthesia, lateral inclination and postoperatively. The modified maneuver for traction under general anesthesia is the one which showed greater flexibility, besides presenting higher radiographic similarity to postoperative aspects. CONCLUSION: Among the radiographic modalities evaluated the study under anesthesia with traction and reduction showed better correlation with postoperative radiographic appearance. Level of Evidence IV, Case Series. .

Traumatic L5-S1 spondylolisthesis in a 15-year-old: a case report.

Traumatic spondylolisthesis is a rare injury resulting from complex trauma and high-energy mechanisms. We present a case report of traumatic spondylolisthesis at the L5-S1 disc space of a patient who was buried after a wall fell on his back. In the physical examination, bilaterally decreased muscle strength was observed. Examination images indicated a 90% slip at L5-S1. Surgical treatment was provided with a posterior and anterior approach using pedicle fixation and an anterior cage. After 4 months, there was significant recovery of muscle strength in the lower limbs.

Renal nitric oxide synthase and antioxidant preservation in Cyp1a1-Ren-2 transgenic rats with inducible malignant hypertension.

BACKGROUND: Dietary administration of 0.30% indole-3-carbinol (I3C) to Cyp1a1-Ren2 transgenic rats (TGRs) generates angiotensin II (ANG II)-dependent malignant hypertension (HTN) and increased renal vascular resistance. However, TGRs with HTN maintain a normal or slightly reduced glomerular filtration rate. We tested the hypothesis that maintenance of renal function in hypertensive Cyp1a1-Ren2 TGRs is due to preservation of the intrarenal nitric oxide (NO) and antioxidant systems. METHODS: Kidney cortex, kidney medulla, aortic endothelial (e) and neuronal (n) nitric oxide synthase (NOS), superoxide dismutases (SODs), and p22phox (nicotinamide adenine dinucleotide phosphate-oxidase subunit) protein abundances were measured along with kidney cortex total antioxidant capacity (TAC) and NOx. TGRs were fed a normal diet that contained 0.3% I3C or 0.3% I3C + candesartan (AT1 receptor antagonist; 25mg/L in drinking water) (n = 5-6 per group) for 10 days. RESULTS: Blood pressure increased and body weight decreased in I3C-induced TGRs, while candesartan blunted these responses. Abundances of NOS, SOD, and p22phox as well as TAC were maintained in the kidney cortex of I3C-induced TGRs with and without candesartan, while kidney cortex NOx production increased in both groups. Kidney medulla eNOS and extracellular (EC) SOD decreased and nNOS were unchanged in both groups of I3C-induced TGRs. In addition, a compensatory increase occurred in kidney medulla Mn SOD in I3C-induced TGRs + candesartan. Aortic eNOS and nNOS∝ fell and p22phox and Mn SOD increased in hypertensive I3C-induced TGRs; all changes were reversed with candesartan. CONCLUSIONS: The preservation of renal cortical NO and antioxidant capacity is associated with preserved renal function in Cyp1a1-Ren2 TGRs with ANG II-dependent malignant HTN.

Tomographic index as auxiliary criteria for surgery indication in fracture dislocation of acetabulum posterior wall.

There are situations which the tomographic exam is done on the affected hip or situations where the contralateral hip presents abnormalities that make it impossible to compare. In this study we aimed to evaluate a tomographic index that does not require comparison between the both hips. Twenty two patients with unilateral acetabular fracture dislocation with fracture of posterior wall were studied. We established the relationship between the remaining posterior wall and the femoral head diameter (head/wall index-H/W index). We evaluated 45 two-dimensional computed tomography scan in normal hips and established the H/W index. In 45 normal hips we simulated a posterior wall fracture with involvement of 25% and 30% of the posterior wall and calculated the H/W index. We divided into five groups with five different H/W index (fractured group with non surgical treatment; fractured group; normal group; normal group with simulated fracture of 25% and; 30% of the posterior wall). 2.4 was the lowest limit of confidence interval of the group with 25% of the posterior wall fracture. When we analyzed the confidence interval of the 30% fracture group the upper limit of the confidence interval was 2.7, close to the lower limit of the surgical group that was 2.9. Thus, we suggest the 2.4 the H/W index limit as an auxiliary criteria to indicate whether or not to operate. H/W index is helpful to decide whether or not surgery indication in the fracture dislocation of the posterior wall of the acetabulum.

Cirurgia de hérnia de disco lombar em atleta de triathlon com monitoração neurofisiológica intraoperatória / Herniated lumbar disc surgery in triathlon athletes with intraoperative neurophysiologic monitor

Intraoperative neurophysiologic monitoring was performed in a patient by somatosensory evoked potential, motor evoked potential and free-running electromyography with intraoperative stimulation. It was verified that after decompression, there was an increase in the amplitude of motor evoked potential responses, showing an immediate improvement of the treated levels. Intraoperative neurophysiologic monitoring for surgical lumbar disc herniation in an athlete allowed a dynamic neurophysiological diagnosis, differentiation of the involvement of compression at the central or foraminal levels, and clinical awareness of the iatrogenic damage, thereby increasing safety.

Foi realizada em um paciente a monitorização intraoperatória neurofisológica com potencial somatossensitivo, motor e eletroneuromiografia contínua com estimulação intraoperatória. Depois da descompressão, ocorreu aumento da amplitude de resposta do potencial evocado motor, mostrando imediata melhora dos níveis tratados. A monitorização neurofisiológica intraoperatória para hérnia de disco lombar em um atleta permitiu um diagnóstico neurofisiológico dinâmico, diferenciação da compressão central ou foraminal e diagnosticar qualquer alteração iatrogênica aumentando a segurança.

Arthrogram in Legg-Calvé-Perthes disease.

There is a consensus among researchers that the treatment for Legg-Calvé-Perthes disease, whether conservative or surgical, is always based on the concept of "containment," that is, maintaining the femoral head inside the acetabulum socket throughout the entire evolution of the disease. Thus, the size and shape of the proximal femoral epiphysis should be monitored during the evolution of the disease. Although diagnosis is carried out by conventional radiographies in many medical institutions, this examination does not give us this information. Therefore, it becomes necessary to resort to other examination techniques, such as pneumoarthrography and magnetic resonance imaging. In our institution, we noticed the importance of hip arthrography in Legg-Calvé-Perthes disease from a study carried out by Laredo in 1985 that classified the disease into 5 groups based on the form and size of the femoral head and its position in the labrum. According to this researcher, group III, which he called "hip at premature arthrographic risk," requires action and yields the best results. The researchers have the opinion that dynamic pneumoarthrography is the best method for establishing an ideal position for the femoral head in relation to the acetabulum when surgical treatment is indicated.

Heparanase isoform expression and extracellular matrix remodeling in intervertebral disc degenerative disease.

OBJECTIVE: To determine the molecules involved in extracellular matrix remodeling and to identify and quantify heparanase isoforms present in herniated and degenerative discs. INTRODUCTION: Heparanase is an endo-beta-glucuronidase that specifically acts upon the heparan sulfate chains of proteoglycans. However, heparanase expression in degenerative intervertebral discs has not yet been evaluated. Notably, previous studies demonstrated a correlation between changes in the heparan sulfate proteoglycan pattern and the degenerative process associated with intervertebral discs. METHODS: Twenty-nine samples of intervertebral degenerative discs, 23 samples of herniated discs and 12 samples of non-degenerative discs were analyzed. The expression of both heparanase isoforms (heparanase-1 and heparanase-2) was evaluated using immunohistochemistry and real-time RT-PCR analysis. RESULTS: Heparanase-1 and heparanase-2 expression levels were significantly higher in the herniated and degenerative discs in comparison to the control tissues, suggesting a possible role of these proteins in the intervertebral degenerative process. CONCLUSION: The overexpression of heparanase isoforms in the degenerative intervertebral discs and the herniated discs suggests a potential role of both proteins in the mediation of inflammatory processes and in extracellular matrix remodeling. The heparanase-2 isoform may be involved in normal metabolic processes, as evidenced by its higher expression in the control intervertebral discs relative to the expression of heparanase-1.

Computed tomographic evaluation of thoracic pedicle screw placement in idiopathic scoliosis.

This retrospective observational study aimed to determine the accuracy of the placement of transpedicular thoracic screws used in idiopathic scoliosis and to evaluate the position and safety of the implants using postoperative computed tomography. Twenty-nine patients who underwent surgery for scoliosis between May 2003 and November 2005 were included in this study. The mean spinal curvature was 67°, and all of the patients had thoracic screws or hooks implanted. The positioning of 78 pedicle screws was evaluated using computed tomography after the free-handed technique was performed. The mean spinal curvature after surgery was 29°. Seventy-six percent of the screws were fully contained within the pedicle. Twenty-one screws breached the pedicle by between 2 and 4 mm (three medially and 18 laterally). Two screws were broken. A neurological deficit was identified in one case after surgery, but the deficit was reversed after the removal of the screws. This screw had a medial breach of greater than 4 mm. Most screws were inserted between the cortical vertebrae. Misplaced screws were most commonly inserted with a lateral cortical perforation.