Journal of Musculoskeletal Research

Background: Meniscal strain patterns are not well understood during dynamic activities. Furthermore, the impact of ACL reconstruction on meniscal strain has not been thoroughly investigated. The purpose of this study was to characterize ACL and meniscal strain during dynamic activities and investigate the strain difference between ACL-intact and ACL-reconstructed ligament conditions. Methods: ACL and medial meniscal strain were measured in-vitro during gait, a double leg squat, and a single leg squat. For each activity kinematics and muscle forces were applied to seven cadaveric specimens using a dynamic knee simulator. Testing was performed in the ACL-intact and ACL-reconstructed ligament conditions. Results: Both the ACL and meniscus had distinct strain patterns that were found to have a significant interaction with knee angle during gait and double leg squat ($P<0.05$). During gait, both tissues experienced lower strain during swing than stance (ACL: 3.0% swing, 9.1% stance; meniscus: 0.2% swing, 1.3% stance). Meniscal strain was not found to be different between ACL-intact and ACL-reconstructed conditions ($P>0.05$). Conclusions: During dynamic activities, the strain in the meniscus was not altered between ACL ligament conditions. This indicates that meniscal mechanics after ACL reconstruction are similar to a healthy knee. These results help further the understanding of osteoarthritis risk after ACL reconstruction.

Introduction: Tendinopathy is a pathology of tendons of multifactorial origin displayed clinically as chronic degenerative tissue resulting in dysfunction and painful musculoskeletal system. Genetic implications in tendinopathy are not fully elucidated. Haptoglobin (Hp) polymorphism has been investigated for potential role in several diseases such as cardiovascular diseases. This study aims at investigating Hp polymorphism potential association with chronic tendinopathy in Jordan. Materials and Methods: A hospital-based case-control study, of 101 patients diagnosed with chronic tendinopathy and 104 age and gender matched controls, was employed and Hpphenotypes distributions were determined using Sodium Dodecyl Sulphate Polyacrylamide gel electrophoresis technique. Results: showed a significant association between tendinopathy cases and controls in relation to Hpphenotypes frequencies (Fisher’s Exact Test, $p=0.001$). Odd ratios showed that the odds of tendinopathy cases in Hp2.1 group were reduced while odds in Hp2.2 and Hp1.1 were increased by 3.22 and 7.34 times, respectively, as likely compared to the controls. Conclusion: Results suggested that Hppolymorphism might play a role in chronic tendinopathy genesis.

Purpose: To find if guitarists had more neural tissue tightness as compared to non-guitarists.

Methods: In this observational analytical study, 40 guitarists (18 to 38 yrs) playing for $\ge$5 years, were recruited and compared with age, gender and BMI matched controls. A questionnaire, physical examination, and four upper limb tension test (ULTT’s) were used to screen the subjects.

Results: The guitarists had increased neural tissue tightness as compared to the corresponding sides of non-guitarists ($p=0.000$). The within-group comparison of guitarist’s indicated that ULTT1 of the left (fretboard limb) was more involved than the right (strumming limb) ($p=0.04$). The Pearson chi-square correlation and point biserial association between ULTT2 and ULTT4 with symptomatic guitarists were significant. Similarly, years of experience, practice hours, and age had a significant correlation with symptoms.

Conclusion: The guitarists had more neural tissue tightness as compared to non-guitarists (left limb$>$right limb). Symptomatic guitarists were found to have more neural tissue tightness in ULTT2 and ULTT4 of both the limbs. The number of years of experience, practice hours, and age were also associated with symptomatic guitarists.

Purpose: Anterior cervical discectomy and fusion is considered as a standard procedure for treating cervical degenerative disc disease. This retrospective study aimed to analyze the radiographic outcome of using a novel cushion titanium cage (Baui Z-Brace Dynamic Fusion Cage). Methods: Fifty-seven patients who received either single-, double-, or three-level interbody fusion surgeries were enrolled. Data from initial status after surgery and postoperative follow-ups for five years were obtained. The patients were divided into three groups according to different levels of cage implantation: 1-level ($n=27$), 2-level ($n=25$), and 3-level ($n=6$). Follow-up time and fusion rate of radiographs were subjected to evaluation. Results: The lateral view of plain radiographs manifests no evident cage subsidence ($>3$mm) and dislodgment in 1-, 2-, and 3-level cage implantation. The follow-up time is three years in 1-level and two years in 2- and 3-level. The CT scans at the final follow-up among different levels of cage implantation manifested bony fusion. The measurement of the Hounsfield unit indicates the bone growth inside the cage compared with control case, demonstrating solid bony fusion among groups at the final follow-up. Conclusions: The data confirm that the specialized Z-shaped structure of the cushion titanium cage may provide the interfragmentary motion stimulating innate bony fusion for sustained improvement.

Question: Can exercise dose be established for bone weakness treatment? Design: Randomized experimental study. Participants: Thirty two adult (12 weeks) Wistar rats (16 males and 16 females) weighed $168.9\pm 18.46$gm. Intervention: Rats were tail suspended for 2 weeks and then randomly divided into four groups; Group I ($n=8$) sacrificed after suspension, Group II ($n=8$) normal cage activities. Group III: ($n=8$) level surface treadmill running. Group IV: ($n=8$) uphill treadmill at angle of 15^∘. The running speed was 12m/min for a period of 30min daily at frequency of 5 days/week for 6 weeks. Outcome measures: Histomorphometric analysis of distal femurs of right hind limbs to measure bone architectural parameters (cortical thickness, Tb.Th, Tb.Nm, Tb.Sp, Tb.Ar, Bone marrow area and density and TBA). Results: Significant improvements were shown in bone architecture in distal femur of Group IV ($p<0.05$) compared to both Group I and Group II. No significant improvement in distal femur in Group III ($p>0.05$) compared to both Group I and Group II. The percentage of change was found to be 62–96% between Group IV and Group II and 72– 82% between Group IV and Group I. Conclusion: The results suggested that uphill treadmill running exercises were effective to induce changes in bone tissue in the form of changing trabecular dimensions and density. The induced structural improvement was site specific and dose dependent.

Managing osteophyte in elbow osteoarthritis (OA) is not an easy task. In the review of the subject hereby, the molecular biology and biomechanics of osteophyte formation will be addressed in composite detail. A number of basic and clinical science research studies that have evaluated the importance and significant role of growth factors, cytokines production, receptors expression, proteoglycans, and alarmins secretion will be included. At the same time, it is notable that the osteophyte formation has not been thoroughly evaluated with respect to its biomechanics, stress and strain pattern on the joint, and its relation to growth plate and the differences that may exist between animal and human joints. Namely, a few studies have begun to look at this particular aspect of osteophyte formation, which does not cover the issue of the graded biomechanical response to the osteophyte formation. The findings of this study can conclude that biomechanical understanding of osteophyte formation has the potential to give a better solution for medical and surgical management of osteophyte formation in different joints and particularly in elbow joint. As such, the proper management of elbow OA with its significant osteophyte formation requires a comprehensive understanding of biology and biomechanics of osteophyte formation.