Imaging Biomarkers of Peripheral Nerves: Focus on Magnetic Resonance Neurography and Ultrasonography.

Peripheral neuropathy is a prevalent and debilitating condition affecting millions of individuals globally. Magnetic resonance neurography (MRN) and ultrasonography (US) are noninvasive methods offering comprehensive visualization of peripheral nerves, using anatomical and functional imaging biomarkers to ensure accurate evaluation. For optimized MRN, superior and high-resolution two-dimensional and three-dimensional imaging protocols are essential. The anatomical MRN and US imaging markers include quantitative measures of nerve and fascicular size and signal, and qualitative markers of course and morphology. Among them, quantitative markers of T2-signal intensity ratio are sensitive to nerve edema-like signal changes, and the T1-mapping technique reveals nerve and muscle tissue fatty and fibrous compositional alterations.The functional markers are derived from physiologic properties of nerves, such as diffusion characteristics or blood flow. They include apparent diffusion coefficient from diffusion-weighted imaging and fractional anisotropy and tractography from diffusion tensor imaging to delve into peripheral nerve microstructure and integrity. Peripheral nerve perfusion using dynamic contrast-enhanced magnetic resonance imaging estimates perfusion parameters, offering insights into nerve health and neuropathies involving edema, inflammation, demyelination, and microvascular alterations in conditions like type 2 diabetes, linking nerve conduction pathophysiology to vascular permeability alterations.Imaging biomarkers thus play a pivotal role in the diagnosis, prognosis, and monitoring of nerve pathologies, thereby ensuring comprehensive assessment and elevating patient care. These biomarkers provide valuable insights into nerve structure, function, and pathophysiology, contributing to the accurate diagnosis and management planning for peripheral neuropathy.

Pneumonia in Nervous System Injuries: An Analytic Review of Literature and Recommendations.

Pneumonia is one of the most common complications in intensive care units and is the most common nosocomial infection in this setting. Patients with neurocritical conditions who are admitted to ICUs are no exception, and in fact, are more prone to infections such as pneumonia because of factors such as swallow dysfunction, need for mechanical ventilation, longer length of stay in hospitals, etc. Common central nervous system pathologies such as ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage, neuromuscular disorders, status epilepticus, and demyelinating diseases can cause long in-hospital admissions and increase the risk of pneumonia each with a mechanism of its own. Brain injury-induced immunosuppression syndrome is usually considered the common mechanism through which patients with critical central nervous system conditions become susceptible to different kinds of infection including pneumonia. Evaluating the patients and assessment of the risk factors can lead our attention toward better infection control in this population and therefore decrease the risk of infections in central nervous system injuries.

Marrow adipose tissue composition in adults with morbid obesity.

Patients with type 2 diabetes mellitus (T2DM) have increased fracture risk despite normal or increased bone mineral density (BMD). Elevations in marrow adipose tissue (MAT) and declines in MAT unsaturation are both associated with increased skeletal fragility. The objective of our study was to characterize the quantity and composition of MAT in adults with morbid obesity and T2DM, and to evaluate determinants of MAT. We studied 21 adults with morbid obesity prior to bariatric surgery, 8 of whom had T2DM. All subjects underwent 1H-MR spectroscopy of the lumbar spine and femur for assessment of MAT and dual-energy x-ray absorptiometry (DXA) and quantitative computed tomography (QCT) of the lumbar spine and hip for assessment of areal BMD (aBMD) and volumetric BMD (vBMD). Visceral (VAT) and subcutaneous adipose tissue (SAT) were quantified by CT at L1-L2. Subjects with T2DM had higher vBMD of the femoral neck and higher total MAT at the lumbar spine and femoral metaphysis compared to non-diabetic controls (p≤0.04). Lipid unsaturation index (UI) was significantly lower at the femoral diaphysis in T2DM (p=0.03). Within the entire cohort, HbA1c was positively associated with MAT (p≤0.03), and age was associated with higher MAT and lower MAT unsaturation (p≤0.05). Lumbar spine vBMD was inversely associated with lumbar spine MAT (p=0.04). There was an inverse association between SAT and diaphyseal MAT (p<0.05) while there were no associations with VAT. Subjects with morbid obesity and T2DM have higher MAT with a lower proportion of unsaturated lipids, despite higher femoral neck vBMD. MAT is positively associated with age and HbA1c, and inversely associated with vBMD, suggesting that MAT may serve as an imaging biomarker of skeletal health and metabolic risk.

Multiple giant cell tumors of bone arising from multiple fatty tumors.

We describe a patient with a history of giant cell tumor who over the course of 18 years developed multiple fat containing osseous lesions in the pelvis and spine. Two of these lesions subsequently evolved into biopsy proven giant cell tumor of bone. To our knowledge, this phenomenon of giant cell tumors evolving from fat containing lesions has not been described.

Effects of Roux-en-Y gastric bypass and sleeve gastrectomy on bone mineral density and marrow adipose tissue.

Bariatric surgery is associated with bone loss but skeletal consequences may differ between Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), the two most commonly performed bariatric procedures. Furthermore, severe weight loss is associated with high marrow adipose tissue (MAT); however, MAT is also increased in visceral adiposity. The purpose of our study was to determine the effects of RYGB and SG on BMD and MAT. We hypothesized that both bariatric procedures would lead to a decrease in BMD and MAT. We studied 21 adults with morbid obesity (mean BMI 44.1±5.1kg/m2) prior to and 12months after RYGB (n=11) and SG (n=10). All subjects underwent DXA and QCT of the lumbar spine and hip to assess aBMD and vBMD. Visceral (VAT) and subcutaneous (SAT) adipose tissue was quantified at L1-L2. MAT of the lumbar spine and femur was assessed by 1H-MR spectroscopy. Calcitropic hormones and bone turnover markers were determined. At 12months after surgery, mean weight and abdominal fat loss was similar between the RYGB and SG groups. Mean serum calcium, 25(OH)-vitamin D, and PTH levels were unchanged after surgery and within the normal range in both groups. Bone turnover markers P1NP and CTX increased within both groups and P1NP increased to a greater extent in the RYGB group (p=0.03). There were significant declines from baseline in spine aBMD and vBMD within the RYGB and SG groups, although the changes were not significantly different between groups (p=0.3). Total hip and femoral neck aBMD by DXA decreased to a greater extent in the RYGB than the SG group (p<0.04) although the change in femoral vBMD by QCT was not significantly different between groups (p>0.2). MAT content of the lumbar spine and femoral diaphysis did not change from baseline in the RYGB group but increased after SG (p=0.03). Within the SG group, 12-month change in weight and VAT were positively associated with 12-month change in MAT (p<0.04), suggesting that subjects with less weight and VAT loss had higher MAT. In conclusion, RYGB and SG are associated with declines in lumbar spine BMD, however, the changes are not significantly different between the groups. RYGB may be associated with greater decline of aBMD at the total hip and femoral neck compared to SG. MAT content increased after SG and this was associated with lower weight and VAT loss.

Fat accumulation in the tongue is associated with male gender, abnormal upper airway patency and whole-body adiposity.

OBJECTIVE: To examine associations between tongue adiposity with upper airway measures, whole-body adiposity and gender. We hypothesized that increased tongue adiposity is higher in males and positively associated with abnormal upper airway measures and whole-body adiposity. METHODS: We studied subjects who underwent whole-body positron emission tomography/computed tomography to obtain tongue attenuation (TA) values and cross-sectional area, pharyngeal length (PL) and mandibular plane to hyoid distance (MPH), as well as abdominal circumference, abdominal subcutaneous and visceral (VAT) adipose tissue areas, neck circumference (NC) and neck adipose tissue area. Metabolic syndrome was determined from available clinical and laboratory data. RESULTS: We identified 206 patients (104 females, 102 males) with mean age 56±17years and mean body mass index (BMI) 28±6kg/m2 (range 16-47kg/m2). Males had lower TA values (P=0.0002) and higher upper airway measures (P<0.0001) independent of age and BMI (P<0.001). In all subjects, TA was negatively associated with upper airway measures (P<0.001). TA was negatively associated with body composition parameters (all P<0.0001), most notably with VAT (r=-0.53) and NC (r=-0.47). TA values were lower in subjects with metabolic syndrome (P<0.0001). CONCLUSION: Increased tongue adiposity is influenced by gender and is associated with abnormal upper airway patency and body composition parameters.

Short- and Long-Term Reproducibility of Intrahepatic Lipid Quantification by 1H-MR Spectroscopy and CT in Obesity.

OBJECTIVE: This study aimed to assess short- and long-term reproducibility of intrahepatic lipid (IHL) quantification by proton magnetic resonance spectroscopy (H-MRS) and computed tomography (CT). METHODS: Sixteen obese subjects underwent H-MRS using a single-voxel point-resolved single-voxel spectroscopy sequence at 3 T and noncontrast single-slice CT of the liver. Measurements were repeated after 6 weeks and 6 months. Clinical parameters (weight, activity, serum lipids) were collected. Short-term (baseline to 6 weeks) and long-term (baseline to 6 months) reproducibility of IHL was assessed by coefficient of variance (CV), SD, and intraclass correlation coefficient (ICC). RESULTS: Short-term reproducibility and long-term reproducibility of H-MRS were as follows: CV, 5.9% to 18.8%; SD, 0.7 to 1.9; and ICC, 0.998 to 0.995 (95% confidence interval, 0.942-0.999). Short-term reproducibility and long-term reproducibility of CT were as follows: CV, 4.4% to 14.2%; SD, 2.4 to 8.7; and ICC, 0.766 to 0.982 (95% confidence interval, 0.271-0.994). There was no significant change in clinical parameters (P > 0.3). CONCLUSIONS: Proton magnetic resonance spectroscopy and CT are reproducible methods for short- and long-term quantification of IHL content. Our results can guide sample size calculations for interventional and longitudinal studies.

Rotator Cuff Tear Arthropathy: Pathophysiology, Imaging Characteristics, and Treatment Options.

OBJECTIVE: The purpose of this article is to review the biomechanical properties of the rotator cuff and glenohumeral joint and the pathophysiology, imaging characteristics, and treatment options of rotator cuff tear arthropathy (RCTA). CONCLUSION: Although multiple pathways have been proposed as causes of RCTA, the exact cause remains unclear. Increasing knowledge about the clinical diagnosis, imaging features, and indicators of severity improves recognition and treatment of this pathologic condition.

Assessment of total hip arthroplasty as a predisposing factor for ischiofemoral impingement.

OBJECTIVE: To examine the effect of total hip arthroplasty (THA) on ischiofemoral (IF) and quadratus femoris (QF) spaces with the hypothesis that THA does not affect ischiofemoral relationships. MATERIALS AND METHODS: The study was IRB approved and complied with HIPAA guidelines. We identified consecutive MR examinations (pelvis and/or hip) obtained at our institution in adults (≥18 years old) screened for THA-related complications. Native hips from the same individuals served as controls. We collected medical record data including age, gender, surgical history, and THA designs. Two radiologists independently measured the IF-RAD and IF-MRI (IF space on radiographs and MR imaging, respectively) and QF space (on MR imaging). Groups were compared using ANCOVA controlled for gender. RESULTS: The study group comprised 250 hips (132 subjects; 162 post-THA and 88 native hips). Subjects were aged 59 ± 10 years, with 66 males and 66 females. Comparison of IF-MRI and QF spaces between native and post-THA hips showed no differences (P > 0.12) and IF-RAD was higher in post-THA subjects (P = 0.01). No differences in the IF-MRI and QF spaces were present between native hips and different THA designs (P > 0.4). IF-RAD of metal-on-metal THA was higher than that of native hips (P = 0.01) and trended higher than ceramic-on-polyethylene THA (P = 0.08), with the remaining comparisons showing no significant differences (P > 0.4). CONCLUSIONS: Radiographic- and MRI-based measures in patients with standard THA do not show narrowing of IF and QF spaces.

Comparison of different methods of femoral fixation anterior cruciate ligament reconstruction.

The aim of this study is to compare three modes of femoral fixation, namely Aperfix, Rigidfix and Endobutton, in anterior cruciate ligament (ACL) reconstruction. 120 patients were randomly assigned to three groups, each consisting of 40 patients, and each group was treated by one of the above mentioned methods of femoral fixation. All patients were examined prior to and 24 months after surgery, and they were compared for anterior tibial displacement using the Lysholm score and KT-1000. The three modes of femoral fixation were not significantly different in terms of time of surgery. In the Endobutton group, the Lysholm score rose from 63.21±18.59 prior to ACL reconstruction to 90.64±9.47 after the surgery, while it rose from 65.72±18.74 to 96.22±5.35 in the Aperfix group and from 69.21±17.45 to 90.64±9.47 in the Rigidfix group. Anterior tibial displacement was 3.96±1.58 mm for Endobutton, 4.28±1.48 mm for Rigidfix and 4.03±1.79 mm for Aperfix. Aperfix was indicated to yield a better outcome in terms of instant stability and general results.

Clinical results of using the proximal humeral internal locking system plate for internal fixation of displaced proximal humeral fractures.

Proximal humerus fractures are accounting for 4-5% of all fractures with increasing incidence. Proximal Humeral Internal Locking System (PHILOS) plate is a new plate which permits early mobility and lowers the risk of complications. The aim of this study was to evaluate the functional outcome and the complication rate after using this plate. Between 2006-2008, 37 patients with displaced 2-, 3-, and 4-part fractures of the proximal humerus underwent surgery using PHILOS plate. The mean range of follow-up was 12 months. Twenty patients were aged 60 years and younger, and 17 were aged older than 60 years. The average American Shoulder and Elbow Surgeons (ASES) score at the final follow-up was 77.62. According to Michener and colleagues classification, 5.4% of patients had an excellent outcome, 72.9% were minimally functionally limited, 16.2% were moderately functionally limited, and 5.4% were maximally functionally limited. The average ASES score between patients 60 years and older and those 60 years and younger was not different significantly. One patient developed avascular necrosis of the humeral head, 2 patients developed an infection, and no patients developed a nonunion. Fixation with PHILOS plate can be considered a good method with high union rates for this kind of fracture, especially in the older population with osteoporotic bone.

Comparison of carpal tunnel release with three different techniques.

BACKGROUND: Carpal tunnel syndrome is one of the most common compression neuropathies in the upper limbs and requires surgery if conservative treatment fails. This article compares the result of regular open incision, mid-palmar mini incision and endoscopic technique in carpal tunnel release. METHODS: This is a clinical trial study on 105 patients (10 males, 95 females) within one year, who were surgical candidates. The surgery was done with regular open incision or with mid-palmar small incision. The clinical outcomes were evaluated one week, 4 weeks and 4 months post-surgery. RESULTS: Relief and satisfaction were better in the first month in the endoscopic and mid-palmar mini incision group. All 3 techniques had similar outcomes after 4 months. In the 4-month follow-up, night pain relief, followed by parasthesia relief had the best improvement. Weakness was the symptom with the least improvement. Longer incision cases were associated with more delay to return to work. CONCLUSION: Carpal tunnel release with endoscopic and mini incision techniques have better early satisfaction rates compared to regular open incision, but no difference is seen between the two groups after four months.

Adult tibial shaft fractures - different patterns, various treatments and complications.

BACKGROUND: Tibial Fractures constitute a large number of emergency operations in most trauma centers. There are different approaches for tibial fractures. To our knowledge, there is insufficient evidence to consider post-operative complications in relation to both surgical methods and the types of fractures. Our purpose is to report our experience regarding the efficacy and complications associated with diverse surgical methods of different patterns of tibial shaft fractures in adults. MATERIAL/METHODS: We studied 387 adult patients. The patients' information was registered from the charts and after examination. The methods used were intramedullary interlocking nails, simple intramedullary rods, plating and external fixation. Early and late complications were recorded and by applying the DELPHI method different treatments were compared. Finally, the safest mode of treatment is proposed. RESULTS: In the intramedullary interlocking nails method the most noticeable complication was delayed union and the highest rate of complications was seen in open oblique fractures. In the simple intramedullary rods method the most frequent complication was pain, and in the with butterfly fractures the complications were the most. In the plating method the most frequent complication was pain, and most of the complications were seen in open comminuted fractures. Finally, in the external fixation method the most frequent complication was non-union and complications were the highest in the patients with oblique, comminuted and segmented fractures. CONCLUSIONS: The proposed method to treat transverse, oblique and butterfly fractures is simple intramedullary rods; whereas intramedullary interlocking nails is the better method for comminuted, segmented and spiral fractures.

Avascular necrosis of the femoral head in children with acute lymphoblastic leukemia: a 4- to 9-year follow-up study.

Avascular necrosis of the femoral head is usually seen in children aged 1.5 to 10 years, reaching a peak incidence between the ages of 4 and 9. Avascular necrosis of the femoral head is a known complication of corticosteroid therapy in acute lymphoblastic leukemia. There are few reports in the literature regarding the natural history of this condition, and there is no consensus on its management. This study examined the natural history of avascular necrosis of the femoral head in children with leukemia. From 1993 to 2006, a total of 865 children with acute lymphoblastic leukemia were admitted to the hematology-oncology ward of a children's hospital. The diagnosis of acute lymphoblastic leukemia was established by bone marrow aspiration. Based on clinical and radiographic findings, avascular necrosis of the femoral head was found in 7 patients; these patients underwent follow-up for 4 to 9 years. Avascular necrosis of the femoral head was clinically symptomatic in all of the children, and they had advanced radiographic collapse of the femoral head. However, the head of the femur was not at risk in any patient based on clinical and radiographic findings. Patients received supportive treatment such as abduction brace and physiotherapy. After 4 to 9 years of follow-up, clinical and radiographic results were satisfactory. Provided that the head of the femur is not at risk, avascular necrosis of the femoral head in children with acute lymphoblastic leukemia may be successfully managed with nonoperative care.

Pseudo-patella baja after total knee arthroplasty.

BACKGROUND: One of the complications of total knee arthroplasty (TKA) which has not yet been directly addressed is pseudo-patella baja (PPB). True patella baja (PB) is present when the length of the patellar tendon becomes shorter. PPB is present when the patella tendon is not shortened, but the level of the joint line is elevated. This study was conducted to assess PPB in TKA. MATERIAL/METHODS: Sixty patients who had had a primary TKA at our center between 1995 and 2005 were included. The average follow-up was 27.5 months. The Knee Society Scoring (KSS), lateral knee x-rays and the Blackburne-Peel index were used for assessments. RESULTS: Out of the 60 patients, 43 (72%) demonstrated no joint line elevation or patellar tendon shortening (group A). Fifteen patients (25%) had joint line elevation (group B), and both PB and PPB were present in 2 (3%) patients (group C). KSS was lower in groups B and C compared with group A, but this difference was not statistically significant. The average range of motion (ROM) in group A was significantly higher compared with either group B or C, and patients in groups B and C showed significantly more severe pain compared with group A (P<0.001). CONCLUSIONS: PPB is not an uncommon finding after TKA and is associated with a statistically significant decrease in ROM and an increase in pain. Furthermore, KSS in the PPB group was less than in patients without PPB, although the difference was not statistically meaningful.

Total hip arthroplasty in advanced osteonecrosis: the short-term results by metal-on-metal hip resurfacing.

BACKGROUND: Characteristically, osteonecrosis affects younger patients who typically refer to the orthopedic surgeon for the first time in the third to fifth decades of life, in the late stages of the disease. Femoral metal-on-metal hip resurfacing is as an alternative to conventional total hip arthroplasty in treating osteoarthritis of the hip. Since there are already many reports regarding the successful outcome of resurfacing in advanced osteoarthritis, the purpose of this study was to analyze the clinical outcomes of this procedure in patients with osteonecrosis of the femoral head and to compare them with a matched group of patients with osteoarthritis. MATERIAL/METHODS: This retrospective cohort study evaluated a consecutive series of 52 patients with end-stage osteonecrosis (28 patients) and osteoarthritis (24 patients) of the femoral head, managed by metal-on-metal hip resurfacing in a referral orthopedic center from Feb 2002 to May 2007. Pain, function and deformity were evaluated with the use of the Harris hip score after the operation. Patients were clinically followed for a mean of 41 months. RESULTS: The patients in the osteoarthritis group had a significantly higher mean age than those in the osteonecrosis group (47.88 ± 12.6 vs 30.86 ± 7.5, p=0.003). The clinical outcomes were similar for both groups. There was no significant difference in mean Harris hip score (p=0.347) and hip joint range of motion (p=0.346) between osteonecrosis and osteoarthritis groups after surgery. CONCLUSIONS: On the basis of these initial findings, we recommend MOM resurfacing as a viable treatment option for patients with advanced stages of osteonecrosis.

Post-dural Puncture Headache: A Comparison Between Median and Paramedian Approaches in Orthopedic Patients.

BACKGROUND: Post-dural puncture headache (PDPH) is an iatrogenic complication of spinal anesthesia. Reported risk factors for PDPH include sex, age, pregnancy, needle tip shape and size, bevel orientation, approach and others. Little is known regarding the effect of different approaches on the incidence of PDPH. OBJECTIVES: In this study we aimed to compare the incidence of PDPH in the case of median and paramedian approaches in patients undergoing spinal anesthesia for orthopedic operations. PATIENTS AND METHODS: Patients scheduled for orthopedic surgery under spinal anesthesia between 2007 and 2008 were studied in a double-blinded randomized controlled trial. The patients were randomized to receive spinal anesthesia by either a median (n = 75) or paramedian (n = 75) approach through a 25-gauge Crawford needle. No premedication was given, and all patients received 500 mL of normal saline intravenously and 4 mL of 0.5% isobaric Marcaine 30 minutes prior to surgery in both approaches. RESULTS: Fifteen patients (10%) developed PDPH. There was no significant difference in the incidence of PDPH in both groups, with 7 (9.3%) patients in the median approach group versus 8 (10.7%) in the paramedian approach group developing typical PDPH (P = 0.875). However, a significant difference in PDPH incidence (P = 0.041) was observed between females (9; 16.7%) and males (6; 6.3%). CONCLUSIONS: There is no difference between median and paramedian approaches with respect to PDPH incidence; the paramedian approach is therefore recommended, especially for older patients with degenerative changes in the spine and intervertebral spaces and those who cannot take the proper position. Moreover, the rate of PDPH was found to be significantly higher in females than in males.

Clinical results of reversed V-shaped high tibial corticotomy with minimally invasive surgery without internal fixation devices.

High tibial osteotomy is a method of treating knee osteoarthritis due to genu varum in advanced stages. High tibial osteotomy-associated problems continue to be reported. The purpose of this study was to investigate the clinical results of a new, innovative method of high tibial osteotomy with 3- to 13-year follow-up. Between 1996 and 2006, our new surgical method was performed on 293 patients with medial compartment osteoarthritis and genu varum. All patients were examined preoperatively, 6 months postoperatively, and at final follow-up. The Hospital for Special Surgery Knee Scoring System (HSS) was used at final follow-up, and limb alignment and patient satisfaction were reassessed. Immediate postoperative complications included varus recurrence, knee instability, and peroneal nerve palsy, and no signs of tibial nonunion or infection were observed. At final follow-up, 3 cases of genu recurvatum, 2 cases of peroneal nerve palsy, and 25 cases of loss of correction were observed. Average postoperative HSS score was 85 (range, 47-97), and 97.8% of the patients were satisfied. This new method is a good alternative for the correction of genu varum because it requires a small incision, is soft tissue friendly, is a corticotomy instead of an osteotomy, requires no internal or external fixation devices, has a shorter duration and an acceptable complication and recurrence rate, and results in satisfactory HSS scores and higher patient satisfaction rates.

Modified ilioinguinal approach to the acetabulum and pelvis from beneath the inguinal ligament: a subinguinal approach.

The ilioinguinal approach is favoured for fractures of the anterior part of the pelvis, but it is associated with some technical difficulties and it is not suitable for some complex fractures. In 2008, a modified ilioinguinal approach was introduced by Farid Yr which afforded visualisation of the inside and outside of the pelvis. The approach involves retroperitoneal access below the inguinal ligament to preserve the integrity of the inguinal canal and allows exposure of anterior and medial wall fractures as well as the anterior hip capsule. Despite the dimensions of the procedure, closure is anatomical because repair of the inguinal canal floor is not required. We report the use of this approach in 17 patients with T-type fractures of the acetabulum, transverse fractures of acetabulum, Tile C1 pelvic fractures, malunion of the pelvis and acetabular dysplasia. The approach is recommended in complex cases of acetabular surgery (including obese or muscular patients) and complicated or old fractures in which a better exposure is required. It is useful in visualisation of the anterior wall and labrum and intra articular structures, and in viewing the internal anatomy of the pelvis and acetabulum. It may be a suitable approach for periacetabular osteotomy.