Strain Ratio Measurements of Patellar and Achilles Tendons With Different Reference Regions in Healthy Volunteers.

Strain ratio measurements of tendons vary because of the reference tissue selection. The main purpose of this study is to highlight, in detail, the numeric variability attributable to the use of various reference materials on strain ratio measurements of patellar and Achilles tendons. Measurements were performed at the proximal, middle and distal thirds of the patellar and Achilles tendons on the dominant site of healthy volunteers. A total of 3 references were used: the Hoffa's fat pad for the patellar tendon, the Kager's fat pad for the Achilles tendon, subcutaneous tissue and Aquaflex gel pads (Parker Laboratories, Fairfield, NJ, USA) for both tendons. Although the same methods were used by the same physician for each tendon site on repeated measurements, strain ratio values had numeric variability with various reference materials in each measurement. Therefore, comparison of numeric strain ratio results of various studies with various reference materials could confuse the clinical interpretations of these numeric data, and, using a reference material with standard stiffness like Aquaflex ultrasound gel pads, should be considered by verifying these results with further studies.

Is quality of life related to risk of falling, fear of falling, and functional status in patients with hip arthroplasty?

OBJECTIVE: The aim of the study was to investigate the relation between health-related quality of life and risk of falling, fear of falling, and functional status in patients with hip arthroplasty. METHODS: In this cross-sectional study, 48 hips of 45 patients who aged between 33 and 79 (53.56 ± 12.50) years and had cementless total hip arthroplasty between 2010 and 2014 were evaluated. Twenty-seven of the patients participated in the study were female (60.0%) and 18 were male (40.0%). Health-related quality of life with Nottingham Health Profile, function of the hip joint with Harris Hip Score, risk of falling with Performance-Oriented Motion Assessment I, and fear of falling with Falls Efficacy Scale were assessed. In addition, chair stand test, 40-m walk test, stair-climb test, and single leg stance test were carried out. In analysing the relationships between these parameters, Pearson correlation analysis was employed. The level of significance was considered as p < 0.05. RESULTS: Among the cases, who were evaluated 87.10 ± 45.22 (22.43-214.71) weeks after the operation, a significant correlation was found between health-related quality of life and risk of falling, function of hip joint, and functional tests (p < 0.05). CONCLUSION: The evaluation of the factors related to health-related quality of life in hip arthroplasty patients may help identify patient needs and guide the rehabilitation process.

The association between different molecular weights of hyaluronic acid and CHAD, HIF-1α, COL2A1 expression in chondrocyte cultures.

The aim of the present study was to investigate the effects of three different formulations of hyaluronic acid (HA): Low molecular weight (MW) Sinovial One®, medium MW Viscoplus® and high MW Durolane®, on chondrocyte proliferation and collagen type II (COL2A1), hypoxia-inducible factor 1α (HIF-1α) and chondroadherin (CHAD) expression in primary chondrocyte cultures. Standard primary chondrocyte cultures were established from osteochondral tissues surgically obtained from 6 patients with gonarthrosis. Cell morphology was evaluated using an inverted light microscope; cell proliferation was determined with a MTT assay and confirmed with acridine orange/propidium iodide staining. Levels of CHAD, COL2A1 and HIF-1α expression were assessed using specific TaqMan gene expression assays. The results demonstrated the positive effect of HA treatment on cell proliferation, which was independent from the MW. COL2A1 expression increased in the medium and high MW HA treated groups. It was observed that HIF-1α expression increased in the high MW treated group alone. CHAD expression increased only in the medium MW HA treated group. Evaluation of gene expression revealed that levels of expression increased as the duration of HA application increased, in the medium and high MW HA treated groups. In terms of increased viability and proliferation, a longer duration of HA application was more effective. Taken together, it may be concluded that the administration of medium and high MW HA may be a successful way of treating diseases affecting chondrocytes in a clinical setting.

A Concise Review on the Use of Mesenchymal Stem Cells in Cell Sheet-Based Tissue Engineering with Special Emphasis on Bone Tissue Regeneration.

The integration of stem cell technology and cell sheet engineering improved the potential use of cell sheet products in regenerative medicine. This review will discuss the use of mesenchymal stem cells (MSCs) in cell sheet-based tissue engineering. Besides their adhesiveness to plastic surfaces and their extensive differentiation potential in vitro, MSCs are easily accessible, expandable in vitro with acceptable genomic stability, and few ethical issues. With all these advantages, they are extremely well suited for cell sheet-based tissue engineering. This review will focus on the use of MSC sheets in osteogenic tissue engineering. Potential application techniques with or without scaffolds and/or grafts will be discussed. Finally, the importance of osteogenic induction of these MSC sheets in orthopaedic applications will be demonstrated.

Are We Using Slow-Acting Symptomatic Chondroprotective Drugs Conscious Enough?

BACKGROUND: Osteochondral injuries constitute an entity that is widespread and can be seen in patients of all ages. Actual treatment modalities aim to relieve pain, obtain full range of movement of the joint, and improve the quality of life. There are many slow-acting chondroprotective agents prevalently used in the United States that are classified as nutritional support but not as medicines . This study presents the importance of clinical adverse effect profiles as well as the pharmacological mechanism of action and application of combinations of drugs that are widely prescribed and not subjected to control. METHODS: Electronic databases were searched with keywords about the chondroprotective drugs without any language restriction. Evaluations of the descriptive statistics were represented via Microsoft Office Excel 2010 lists in the form of a mean±standard deviation or frequency (%). The first evaluation showed that 1502 studies were potentially relevant. Following exclusion of the 1277 studies which were not clinical, full versions of the remaining 225 studies were subjected to further evaluation. No controlled, blinded, randomized and/or comparative studies met the inclusion criteria of the study, and no studies evaluated the comparative clinical results of the hyaluronan of different molecular weights. RESULTS: The findings of this study concluded that especially when prescribing drugs with ingredients like GS and CS, many patients' pre-existing conditions must be considered, such as whether the patient has a glucose intolerance or not. Additionally, mineral toxication should be considered since the drugs contain minerals, and after the application of injected hyaluronan, complications should be considered. CONCLUSION: Clinical, controlled and comparative studies about the use of chondroprotective drugs must be performed to define the benefits of these drugs, if any, in order to determine the most suitable time for operative intervention.

Can a Biodegradable Implanted Bilayered Drug Delivery System Loaded with BMP-2/BMP-12 Take an Effective Role in the Biological Repair Process of Bone-Tendon Injuries? A Preliminary Report.

BACKGROUND: Use of biodegradable and biocompatible materials in the orthopedic surgery is gaining popularity. In this research, the rate of controlled release of a bilayered prototype biomaterial designed to promote osteoblastic and tenoblastic activity was calculated using pharmacochemical methods. METHODS: The first part of the design, composed of a sodium tetraborate, polyvinyl alcohol, and starch based hydrogel, was loaded with bone morphogenic protein-2. The second part which was composed of a sodium tetraborate, polyvinyl alcohol, and chitosan based hydrogel was loaded with bone morphogenic protein-12. Osteochondral and tendon tissue specimens were obtained from patients with a diagnosis of gonarthrosis and primary bone cells and tendon cells cultures were prepared following treatment with collagenase enzyme. Cell samples were collected from the groups by means of an invert light microscope and environmental scanning electron microscope underwent at the 1st and 21st days. The level of osteogenic differentiation was measured by the activity of alkaline phosphatase. For the statistical evaluation of the obtained data, groups were compared with post hoc Tukey test following analysis of variance. Level of significance was accepted to be <0,01. RESULTS: Both osteogenic and tenogenic stimulation were observed in the cultured specimens. In comparison to the control groups, the rate of proliferation of healthy cells was found to be higher in the groups to which the design was added (p < 0.01). CONCLUSIONS: Our research is a preliminary report that describes a study conducted in an in vitro experimental setting. We believe that such prototype systems may be pioneers in targeted drug therapies after reconstructional surgeries.

Is it Possible to Treat Osteosarcoma Using Oligonucleotides Confined into Controlled Release Drug Delivery Systems?

PURPOSE: The present study aimed to analyze the researches that are at the experimental phase concerning osteosarcoma treatment. The researches included drug delivery systems which allow controlled release and imbue small interfering-/micro- ribonucleic acid. METHODS: Without any language preference, we searched US National Library of Medicine National Institutes of Health, Embase, OVID, Cochrane Library database of clinical trials from 1843 to May 25, 2016 and traced all the references of incorporated documents. The data were evaluated using descriptive statistics and the results are shown as frequency (%). RESULTS: We haven't encountered any drug delivery system in which Small interfering ribonucleic acid/ micro ribonucleic acid oligonucleotides were embedded successfully against osteosarcoma. There has been only one research in which hairpin-ribonucleic acid was embedded. CONCLUSION: It was considered that drug delivery system enabling controlled oligonucleotide release in the treatment period of osteosarcoma was not projected for the clinical use. However, it cannot be neglected that the mentioned experimental studies with regard to osteosarcoma treatment establish the basis of target therapies. The method in question looks promising regarding effective treatment of osteosarcoma in the future.

Iopromide- and gadopentetic acid-derived preparates used in MR arthrography may be harmful to chondrocytes.

BACKGROUND: Magnetic resonance arthrography, a procedure through which contrast agents containing gadolinium and/or iopromide are administered intra-articularly, has become a useful tool in musculoskeletal diagnosis. Nevertheless, despite being considered safe for systemic use, certain tissue toxicities have been identified for both drugs. In this study, the effects of short-term exposure of human primary chondrocyte cell cultures to gadolinium and/or iopromide contrast agents were examined by assaying for stage-specific embryonic antigen-1 (SSEA-1) protein expression (a chondrogenic differentiation marker), cell viability, toxicity, and proliferation. METHODS: Human articular chondrocytes were grown in monolayer culture and were exposed to iopromide and/or gadolinium diethylenetriamine-pentaacetate (Gd-DPT) for 2 and 6 h. Cell cultures with no drug exposure were used as the control group. Cell differentiation status was assessed according to SSEA-1 protein expression. Contrast agent effects on cell viability and proliferation were analyzed using MTT analysis. Further, changes in cell morphology in relation to the control group were evaluated using inverted light microscopy, environmental scanning electron microscopy (ESEM), and 3-tesla magnetic resonance imaging. The obtained data were statistically compared. RESULTS: When compared with the control group, both SSEA-1 protein expression and cell proliferation were lowest in the Gd-DPT group (P = 0.000). There was a statistically significant correlation between SSEA-1 expression and MTT results (rho = 0.351; P = 0.003). CONCLUSIONS: Nevertheless, the data obtained from in vitro experiments may not directly correspond to clinical applications. However, the mere fact that a drug used solely for diagnostic purposes may repress chondrocyte cell proliferation should be carefully considered by clinicians.

Effects of weighted and un-weighted pendulum exercises on ultrasonographic acromiohumeral distance in patients with subacromial impingement syndrome.

BACKGROUND: Although functional results of combined rehabilitation programs are reported, there have been no reports studying the effects of solo pendulum exercises on ultrasonographic measurements of acromiohumeral distance (AHD). OBJECTIVE: To investigate the effects of weighted and un-weighted pendulum exercises on ultrasonographic AHD and clinical symptoms in patients with subacromial impingement syndrome. METHODS: Patients with subacromial impingement syndrome were randomized to performing weighted (1.5 kilograms hand held dumbbell, N= 18) or un-weighted (free of weight, N= 16) pendulum exercises for 4 weeks, 3 sessions/day. Exercises were repeated for each direction of shoulder motion in each session (ten minutes). Clinical situation was evaluated by Constant score and Shoulder Pain Disability Index (SPADI). Ultrasonographic measurements of AHD at 0°, 30° and 60° shoulder abduction were performed. All clinical and ultrasonographic evaluations were performed at the beginning of the exercise program and at end of 4 weeks of exercise program. RESULTS: Thirty-four patients (23 females, 11 males; mean age 41.7 ± 8.9 years) were evaluated. Significant clinical improvements were detected in both exercise groups between pre and post-treatment evaluations (p < 0.05). There was no significant difference for pre and post-treatment AHD measurements at 0°, 30°, and 60° shoulder abduction between groups (p > 0.05). There was no significant difference for pre and post-treatment narrowing of AHD (narrowing of 0°-30°, and 0°-60°) between groups (p > 0.05). CONCLUSION: While significant clinical improvements were achieved with both weighted and un-weighted solo pendulum exercises, no significant difference was detected for ultrasonographic AHD measurements between exercise groups.

Effects of Cigarette Smoking on Elastographic Strain Ratio Measurements of Patellar and Achilles Tendons.

OBJECTIVES: The aim of this study was to explore the sonographic and elastographic properties of patellar and Achilles tendons in smoking and nonsmoking otherwise healthy adults. METHODS: We conducted a level 3 case-control analytical study. Smoking and nonsmoking volunteers (>18 years) without musculoskeletal system disorders were included in the study. Demographic characteristics and smoking habits (pack-years) were recorded. Proximal, middle, and distal third thicknesses of the patellar and Achilles tendons were measured by B-mode sonography. Strain ratio measurements of the same regions were measured by real-time ultrasound elastography. RESULTS: A total of 69 participants (57 male and 12 female; mean age ± SD, 35.5 ± 7.8 years) were evaluated in the study. Smoking (n = 35) and nonsmoking (n = 34) groups had no significant differences in terms of age, body mass index, sex, and activity level (all P > .05). Proximal, middle, and distal thirds of the patellar and Achilles tendons were significantly thinner in the smoking group (all P < .05). Furthermore, strain ratio measurements in the same regions were significantly lower in the smoking group (all P< .05). Patellar tendon thicknesses and strain ratios had negative correlations with the smoking amount (all P < .05). CONCLUSIONS: Thickness and strain ratio measurements of patellar and Achilles tendons were reduced (thinner and harder tendons) in smokers. Clinical implications of these morphologic and elastographic changes should be investigated in future studies.

Is there a treatment protocol in which platelet-rich plasma is effective?

AIM: We aimed to reveal whether there are prospective suggestions for effective and standard platelet-rich plasma applications. METHODS: We searched for clinical trials and traced all the references of incorporated documents. RESULTS: In literature, there was no study indicating which disease is treated by which mechanism of action, how much dose and content are prepared and applied, when the treatment is applied and how many cures are applied. CONCLUSION: Guides introducing which concentrations of PRP are used for which diseases are to be prepared immediately by a committee which is comprised of primarily orthopedists, clinical pharmacologists and toxicologists.

Real-time elastography of patellar tendon in patients with auto-graft bone-tendon-bone anterior cruciate ligament reconstruction.

INTRODUCTION: Patellar tendon donor site has been previously evaluated in patients with auto-graft bone-tendon-bone (BTB) anterior cruciate ligament (ACL) reconstruction using either magnetic resonance imaging or B mode ultrasound. However, donor site patellar tendon strain ratio-reflecting structural features-has not been studied with US elastography. Here, we ascertain real-time elastography properties of patellar tendon donor site and clinical relevance of these properties in patients with auto-graft BTB ACL reconstruction in the postoperative period. METHODS: Patients who underwent ACL reconstruction using BTB autograft were evaluated. Demographic, operative and clinical data (severity of pain, Lysholm Knee score, sit to stand test, packages/year for smoking amount) were noted. Patellar tendons of the operated knees were evaluated by ultrasound (length and thickness) and sonoelastography (strain ratio). The healthy knees of the patients constituted the control group. RESULTS: Eighteen patients (17 M, 1 F; mean age 30.9 ± 7 years) were evaluated. Mean postoperative follow-up period was 22.1 ± 2.6 (range 18-26) months. Patellar tendons were shorter and thicker on the operated side when compared with the contralateral side (both p = 0.001). Patellar tendon strain ratios of the operated side were lower than the contralateral side (harder tendon on operated side). While there was no correlation between strain ratios and clinical variables (age, BMI, postoperative time, severity of pain, Lysholm score, all p values > 0.05), significant negative correlations were detected between strain ratios of proximal, middle and distal thirds of operated side and amount of smoking (p = 0.008, r = -0.607, p = 0.009, r = -0.598, p = 0.023, r = -0.533, respectively). CONCLUSION: Patellar tendons on the operated sides seemed to thicken and shorten with decreased strain ratios at the donor side compared to the healthy side at an average of 2-year follow-up in patients with ACL reconstruction using BTB autograft, and amount of smoking had negative relationship with strain ratio of donor patellar tendon.

Relationship of side dominance and ultrasonographic measurements of pronator quadratus muscle along with handgrip and pinch strength.

AIMS: We ascertained effects of hand dominance in both right and left-handed volunteers on the thickness and cross sectional area (CSA) of pronator quadratus (PQ) muscle as measured by the axial and sagittal views of ultrasound imaging. Secondly, we also aimed to document the extent of the relationship between the PQ measurements and handgrip. MATERIALS AND METHODS: Healthy adults from the volunteer medical staff were included in the study. Handedness was assessed via The Flinders Handedness survey. The sonographic appearance of the PQ was evaluated on sagittal and axial images for both hands. CSA of PQ muscle was digitally drawn and calculated on the axial plane. Handgrip was measured by using adjustable-handle dynamometer. RESULTS: Eighty-nine healthy volunteers were included (54 right and 35 left-handed). Significant difference was detected between dominant and non-dominant hands in CSA and muscle thickness in both right and left-handed volunteers (p<0.05). These measurements were correlated with the handgrip strength (p<0.05, r=0.55, and r=0.43 for right-handed volunteers, r=0.67 and r=0.48 for left-handed volunteers, respectively). There were also significantly high correlations between the measurements of CSA and PQ thickness of the corresponding extremity in both right-handed and left-handed volunteers (p<0.05). CONCLUSIONS: A statistically significant difference exists between dominant and non-dominant hands in CSA and muscle thickness measured by US in both right and left handed volunteers, and this is correlated with handgrip strength. Hand dominance should be considered to compare healthy and affected sites during US of PQ while investigating for occult fractures of distal forearm or PQ atrophy due to anterior interosseous nerve injury.

The Effects of Smoking on Ultrasonographic Thickness and Elastosonographic Strain Ratio Measurements of Distal Femoral Cartilage.

Although adverse effects of smoking on bone health are all well known, data on how smoking interacts with cartilage structure in otherwise healthy individuals remains conflicting. Here, we ascertain the effects of cigarette smoking on sonoelastographic properties of distal femoral cartilage in asymptomatic adults. Demographic characteristics and smoking habits (packets/year) of healthy volunteers were recorded. Medial, intercondylar, and lateral distal femoral cartilage thicknesses and strain ratios on the dominant extremity were measured with ultrasonography (US) and real time US elastography. A total of 88 subjects (71 M, 17 F; aged 18-56 years, N = 43 smokers and N = 45 nonsmokers) were evaluated. Mean amount of cigarette smoking was 10.3 ± 8.9 (1-45) packets/year. Medial, intercondylar and lateral cartilage were thicker in smokers than nonsmokers (p = 0.002, p = 0.017, and p = 0.004, respectively). Medial distal femoral cartilage strain ratio was lower in smokers (p = 0.003). The amount of smoking was positively correlated with cartilage thicknesses and negatively correlated with medial cartilage strain ratios (p < 0.05). Femoral cartilage is thicker in smokers but has less strain ratio representing harder cartilage on the medial side. Future studies are needed to understand how these structural changes in the knee cartilage should be interpreted with regard to the development of knee osteoarthritis in smokers.

Preoperative and postoperative serial assessments of postural balance and fall risk in patients with arthroscopic anterior cruciate ligament reconstruction.

BACKGROUND: Impaired postural balance due to somatosensory data loss with mechanical instability has been shown in patients with ACL deficiency. OBJECTIVE: To assess postural balance in patients with ACL insufficiency prior to surgery and following reconstruction with serial evaluations. METHODS: Thirty patients (mean age of 27.7 ± 6.7 years) who underwent arthroscopic reconstruction of ACL with bone-patellar tendon-bone autograft were examined for clinical and functional variables at preoperative day and postoperative 12th week. Posturographic analysis were performed by using Tetrax Interactive Balance System (Sunlight Medical Ltd, Israel) at preoperative day, at 4th, 8th, and 12th weeks following reconstruction. Data computed by posturographic software by the considerations of the oscillation velocities of body sways is fall risk as a numeric value (0-100, lower values indicate better condition). RESULTS: All of the patients (mean age of 27.7 ± 6.7 years) had significant improvements for clinical, functional evaluations and fall risk (p< 0.05). Mean fall risk was within high-risk category (59.9 ± 22.8) preoperatively. The highest fall risk was detected at postoperative 4th week. Patients had high fall risk at 8th week similar to preoperative value. Mean fall risk decreased to low level risk at 12th week. Preoperative symptom duration had relationships with preoperative fall risk and postoperative improvement of fall risk (p= 0.001, r= -0.632, p= 0.001, r= -0.870, respectively). The improvement of fall risk was higher in patients with symptoms shorter than 6 months (p= 0.001). CONCLUSIONS: According to these results, mean fall risk of patients with ACL insufficiency was within high risk category preoperatively, and fall risk improves after surgical reconstruction, but as the duration of complaints lengthens especially longer than 6 months, the improvement of fall risk decreases following reconstruction.

Sonoelastographic evaluation of the distal femoral cartilage in patients with anterior cruciate ligament reconstruction.

OBJECTIVES: This study aims to evaluate sonoelastographic properties of the distal femoral cartilage in patients with anterior cruciate ligament (ACL) reconstruction. PATIENTS AND METHODS: Demographic characteristics and operative data of 28 patients (27 males, 1 female; mean age 31.7±7.1 years; range 22 to 48 years) with unilateral ACL reconstruction were evaluated. Reconstruction was performed with patellar tendon graft in 22 patients (78.6%) and hamstring tendon graft in six patients (21.4%). Lysholm knee score was used for functional evaluation and chair stand test was used for lower extremity strength. Medial, intercondylar, and lateral distal femoral cartilage thicknesses of operated knees and healthy knees were measured with B-mode ultrasound, while strain ratios were measured with real time sonoelastography. RESULTS: Postoperative mean follow-up duration was 20.4±9.8 months. Mean Lysholm knee and patient satisfaction scores were 88.0±8.5 and 8.2±1.8, respectively. Cartilage thicknesses were similar between operated and healthy knees (all p>0.05). Sonoelastographic strain ratio of medial distal femoral cartilage in operated knees was significantly higher (softer cartilage) (p=0.026). There was a negative correlation between strain ratio difference of medial cartilage of operated knees and lower extremity muscle strength (p=0.009, r= -0.487). CONCLUSION: While there was no difference for cartilage thickness between operated and healthy knees in B-mode ultrasound evaluation, detection of sonoelastographic strain ratio changes in medial distal femoral cartilage on the operated sides may indicate early structural changes following ACL reconstruction. Further studies are required to highlight the clinical effects of this relationship between the changes in cartilage structure and sonoelastography features.

TEST-RETEST RELIABILITY OF TETRAX® STATIC POSTUROGRAPHY SYSTEM IN YOUNG ADULTS WITH LOW PHYSICAL ACTIVITY LEVEL.

PURPOSE/BACKGROUND: Assessment of postural sway with force plates can be affected by type of measurement and various clinical parameters such as age and activity level of the individual person. For this reason, variability is detected in postural reactions of healthy subjects without balance impairment. Test-retest reliability of postural sway in adolescent athletes has been measured using a force plate and additional test-retest studies have been suggested for subjects of different age groups with different activity levels. Therefore, the purpose of this research was to assess test-retest reliability of Tetrax® Static Posturography in young adults with low physical activity level, and examine the relationship between posturography results and low activity level. METHODS: Young adults older than 18 years of age were included in the study. Demographic characteristics of the cases were recorded including age, weight, height, body mass index (BMI, kg/m2) and dominant extremity. Number of falls in the previous six months, lower body endurance (sit to stand test) and single-leg eyes closed stance test were recorded. Activity level of participants was determined according to the International Physical Activity Questionnaire (IPAQ). Posturographic evaluation of all volunteers was completed using the Tetrax® Interactive Postural Balance System (Sunlight Medical Ltd, Israel). Fall risk and general stability index (SI) calculated by the Tetrax® were recorded. Following the first test, measurements were repeated 24 to 48 hours later for reliability purposes. RESULTS: Sixty-five subjects (28 male, 37 female; mean age 22.2 ± 1.1 years, mean BMI 22.6 ± 3.3 kg/m(2)) were evaluated. All participants were classified as minimally active according to mean IPAQ score (1042.1 ± 517.7 [231 - 2826] MET- minutes per week). ICC scores between the first and second tests for fall index and total stability index were excellent (ICC2,1=0.858, 0.850, respectively). Fall risk determined by using the Tetrax® device was negatively correlated with lower body endurance (p=0.001, r=-0.446), vigorous activity score (p=0.011, -0.312) and total activity score (p=0.029, r=-0.271), and positively correlated with single leg stance score (p=0.001, r=0.606). There was a weak correlation between fall risk history and the fall risk determined by using Tetrax® device (p=0.04, r=0.255). There were no correlations between fall risk and height, weight, and BMI (p>0.05). CONCLUSIONS: The results demonstrated the high test-retest reliability of Tetrax® interactive balance system in young healthy adults with low physical activity level. Future studies are needed to determine the effectiveness of increasing physical activity level on postural control. LEVEL OF EVIDENCE: III.

Chronic Exposure to Static Magnetic Fields from Magnetic Resonance Imaging Devices Deserves Screening for Osteoporosis and Vitamin D Levels: A Rat Model.

Technicians often receive chronic magnetic exposures from magnetic resonance imaging (MRI) devices, mainly due to static magnetic fields (SMFs). Here, we ascertain the biological effects of chronic exposure to SMFs from MRI devices on the bone quality using rats exposed to SMFs in MRI examining rooms. Eighteen Wistar albino male rats were randomly assigned to SMF exposure (A), sham (B), and control (C) groups. Group A rats were positioned within 50 centimeters of the bore of the magnet of 1.5 T MRI machine during the nighttime for 8 weeks. We collected blood samples for biochemical analysis, and bone tissue samples for electron microscopic and histological analysis. The mean vitamin D level in Group A was lower than in the other groups (p = 0.002). The mean cortical thickness, the mean trabecular wall thickness, and number of trabeculae per 1 mm2 were significantly lower in Group A (p = 0.003). TUNEL assay revealed that apoptosis of osteocytes were significantly greater in Group A than the other groups (p = 0.005). The effect of SMFs in chronic exposure is related to movement within the magnetic field that induces low-frequency fields within the tissues. These fields can exceed the exposure limits necessary to deteriorate bone microstructure and vitamin D metabolism.

Obliteration of Intercondylar Notch Mimicking Flexion-Extension Gap Imbalance in a Cruciate Retaining Total Knee Arthroplasty.

Following total knee arthroplasty (TKA), the most frequent cause of extension deficit and limitation of range of motion in early postoperative period is related to improper tensioning of soft tissues and failure to balance extension and flexion gaps. If a cruciate retaining (CR) prosthesis is the planned implant, then attention should be given to balancing the posterior cruciate ligament (PCL), and any factor that alters this balance may also cause deterioration of knee balance in postoperative period. Here, we report on an unusual case referred from another hospital because of continuous pain and restriction of knee motion in early postoperative period following CR-designed TKA that was initially thought to be due to flexion-extension imbalance. However, during the revision procedure, extruded cement to the intercondylar notch was found to be both mechanically blocking terminal extension and limiting flexion by possible mechanism of irritation of the synovial nerve endings around the stretched anterior fibers of PCL during flexion. This case was successfully treated by removal of extruded cement from intercondylar notch to decompress PCL, polyethylene exchange, and secondary patellar resurfacing.

Ultrasonographic evaluation of the flexor pollicis longus tendon in frequent mobile phone texters.

OBJECTIVE: The aim of this study was to assess flexor pollicis longus tendon by using ultrasound imaging in frequent mobile phone texters. SUBJECTS: In total, 149 subjects, aged 18-40 yrs, were recruited as frequent mobile phone texters (n = 71) and infrequent texters (n = 78). METHODS: Demographic data and estimate frequency of texting were noted. Thumb pain during activity, range of motion for thumb joints, grip and pinch strengths, and Quick Disabilities of arm, shoulder, and hand were evaluated. Standardized bilateral ultrasound evaluations were performed using a linear array probe, and tendon area measurements were done with axial imaging at midthenar region and midproximal phalangeal region with manual trace technique. RESULTS: The groups were similar except for the mean estimate number of messages/month (P = 0.001). Whereas grip and pinch strength values were significantly higher (frequent texter group, P = 0.001; infrequent texter group, grip strength P = 0.018; pinch strengths, P = 0.001) on the texting side in both groups, flexor pollicis longus tendons were larger (P = 0.001) and the activity pain was higher (P = 0.005) on the texting sides only in the frequent texter group. Flexor pollicis longus thickness significantly correlated with messages/month only in the frequent texter group (r = 0.592, P = 0.001). CONCLUSIONS: Flexor pollicis longus tendons seem to be thicker at the midthenar level in subjects who frequently use mobile phone texting. Because this increase in thickness parallels the number of messages per day, the authors believe that further studies are needed to elucidate whether such changes become problematic later on in life.