Differential MMP 1 and MMP 13 expression in proliferation and ligamentization phases of graft remodeling in anterior cruciate ligament reconstruction.

: Graft remodeling in anterior cruciate ligament reconstruction (ACLR) demonstrates three distinct phases: necrosis, proliferation and ligamentization. Biological enhancement involves modulating these processes, but the cellular activities related to extracellular matrix remodeling have not been investigated. We hypothesized that changes in matrix metalloproteinases (MMPs) 1 and 13 expression are involved in the transition of proliferation phase to ligamentization phase of graft remodeling.

A non-invasive biomechanical device to quantify knee rotational laxity: Verification of the device in human cadaveric specimens.

Background: Biomechanical measurement tools have been developed and widely used to precisely quantify knee anterior-posterior laxity after anterior cruciate ligament (ACL) injury. However, validated objective device to document knee rotational laxity, though being developed by different researchers, are not yet widely used in the daily clinical practice. A new biomechanical device was developed to quantify knee internal and external rotations.

User-Adaptive Assistance of Assistive Knee Braces for Gait Rehabilitation.

Patients suffering from neurological and orthopedic diseases or injuries usually have mobility impairment problems, and they require customized rehabilitation training to recover. In recent years, robotic assistive devices have been widely studied for gait rehabilitation. In this paper, methods to determine user-adaptive assistance of assistive knee braces (AKBs) in gait rehabilitation are investigated.

Intra-Articular Delivery of Quercetin Using Thermosensitive Hydrogel Attenuate Cartilage Degradation in an Osteoarthritis Rat Model.

Objective: Quercetin (Que), a bioflavonoid, is both anti-inflammatory and antioxidative. Que has been used as an oral supplement for osteoarthritis (OA) with inconsistent findings because of its low bioavailability. We encapsulated Que in a mPEG-polypeptide thermogel to prolong its bioactivity.

Mobility, prosthesis use and health-related quality of life of bilateral lower limb amputees from the 2008 Sichuan earthquake.

Background:: The 2008 Sichuan Earthquake resulted in many amputees, yet due to the rare incidence, few studies have explored the rehabilitation outcomes and quality of life of bilateral lower limb amputees after major natural disasters.

Objectives:: To evaluate rehabilitation outcomes of 17 young and adult bilateral lower limb amputees under the StandTall rehabilitation programme and to identify factors associated with successful functional recovery of bilateral amputees after large-scale disasters.

Study Design:: Cross-sectional study.

Hydrogen peroxide induced tendinopathic changes in a rat model of patellar tendon injury.

Tendinopathy includes cases with chronic tendon pain and spontaneous tendon ruptures, which is putatively resulted from failed tendon healing. Overuse is a major risk factor of tendinopathy, which can impose mechanical and oxidative stress to tendons. Previous studies investigated the influences of mechanical stress, but the direct impact of oxidative stress on tendon healing remains unclear.

Concise Review: Stem Cell Fate Guided By Bioactive Molecules for Tendon Regeneration.

Tendon disorders, which are commonly presented in the clinical setting, disrupt the patients' normal work and life routines, and they damage the careers of athletes. However, there is still no effective treatment for tendon disorders. In the field of tissue engineering, the potential of the therapeutic application of exogenous stem cells to treat tendon pathology has been demonstrated to be promising.

The reliability and validity of a video-based method for assessing hamstring strength in football players.

Background/objective: Evaluating hamstring strength by isokinetic dynamometry is limited by various practical issues such as time and cost. A video-based Nordic hamstring exercise is introduced as an alternative option. The aims of this study are to evaluate 1.

Reliability, Validity, and Sensitivity of a Novel Smartphone-Based Eccentric Hamstring Strength Test in Professional Football Players.

Purpose: To evaluate the test-retest reliability, sensitivity, and concurrent validity of a smartphone-based method for assessing eccentric hamstring strength among male professional football players.

Methods: A total of 25 healthy male professional football players performed the Chinese University of Hong Kong (CUHK) Nordic break-point test, hamstring fatigue protocol, and isokinetic hamstring strength test. The CUHK Nordic break-point test is based on a Nordic hamstring exercise.

Optimisation of platelet concentrates therapy: Composition, localisation, and duration of action.

Platelet concentrates (PC) generally refers to a group of products that are prepared from autologous blood intended to enhance healing activities. PC therapy is now very popular in treating musculoskeletal injuries; however, inconsistent clinical results urge the need to understand the working mechanism of PC. It is generally believed that the platelet-derived bioactive factors are the active constituents, and their bioavailability in the vicinity of the lesion sites determines the treatment efficacies.

Comparison of treatment effects on lateral epicondylitis between acupuncture and extracorporeal shockwave therapy.

Background: Lateral epicondylitis is one of the most common overuse injuries, and has been reported to reduce function and affect daily activities. There is no standard therapy for lateral epicondylitis. In Hong Kong, acupuncture and extracorporeal shockwave therapy (ESWT) have been popular in treating lateral epicondylitis in recent years.

Osteocalcin expressing cells from tendon sheaths in mice contribute to tendon repair by activating Hedgehog signaling.

Both extrinsic and intrinsic tissues contribute to tendon repair, but the origin and molecular functions of extrinsic tissues in tendon repair are not fully understood. Here we show that tendon sheath cells harbor stem/progenitor cell properties and contribute to tendon repair by activating Hedgehog signaling. We found that () can be used as an adult tendon-sheath-specific marker in mice.

Eccentric hamstring strength deficit and poor hamstring-to-quadriceps ratio are risk factors for hamstring strain injury in football: A prospective study of 146 professional players.

Objectives: The purpose of this study was to investigate whether preseason isokinetic strength measures were predictive of future HSI among professional football players.

Design: Prospective cohort study, Level of evidence 2.

Methods: A total of 169 professional players participated in a preseason isokinetic strength screening, followed by a 10-month competitive season.

Effects of Redox Modulation on Cell Proliferation, Viability, and Migration in Cultured Rat and Human Tendon Progenitor Cells.

Tendon healing is slow and usually results in inferior fibrotic tissue formation. Recently, application of tendon derived stem cells (TDSCs) improved tendon healing in animal studies. In a chicken model, local injection of antioxidants reduced tendon adhesion after tendon injury.

Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

Background: The structural pathology of Achilles tendon (AT) ruptures resembles tendinopathy, but the causes remain unknown. Recently, a number of diseases were found to be attributed to bacterial infections, resulting in low-grade inflammation and progressive matrix disturbance. The authors speculate that spontaneous AT ruptures may also be influenced by the presence of bacteria.

Local administration of Trolox, a vitamin E analog, reduced tendon adhesion in a chicken model of flexor digitorum profundus tendon injury.

Background: Hand flexor tendon injuries are compromised with tendon adhesion. Tendon adhesion forms between flexor tendon and tendon sheath, reduces the range of motion of fingers, and affects their function. Oxidative stress is increased in flexor tendon after injury and might play a role in tendon adhesion formation.

Long noncoding RNA H19 accelerates tenogenic differentiation and promotes tendon healing through targeting miR-29b-3p and activating TGF-β1 signaling.

Tendon injures are common orthopedic conditions, but tendon development and the pathogenesis of tendon injures, such as tendinopathy, remain largely unknown and have limited the development of clinical therapy. Studies on tenogenic differentiation at the molecular level may help in developing novel therapeutic strategies. As novel regulators, long noncoding RNAs (lncRNAs) have been found to have widespread biological functions, and emerging evidence demonstrates that lncRNAs may play important regulatory roles in cell differentiation and tissue regeneration.

Intra-articular injection of an antioxidant formulation did not improve structural degeneration in a rat model of post-traumatic osteoarthritis.

Background/objective: Oxidative stress plays an important role in osteoarthritis (OA), causing inflammation and matrix degradation in joints. Previous studies have shown that antioxidants such as quercetin and vitamin C are potential candidates for treating OA. We aimed to determine whether a formulation of quercetin and vitamin C, together with an iron chelator, could retard OA progression in a post-traumatic OA rat model.

Use of a portable motion analysis system for knee dynamic stability assessment in anterior cruciate ligament deficiency during single-legged hop landing.

Background/objective: Anterior cruciate ligament (ACL) rupture results in knee instability, and patients are often unable to return to their previous level of activity. Current assessments rely on passive laxity tests, which do not correlate with function. Dynamic stability may be a better indicator for return to sport.

Power and endurance in Hong Kong professional football players.

Background: The purpose of this study was to investigate the power and endurance characteristics of Hong Kong professional football players. Training recommendations can be deduced based on the comparison between Hong Kong and international football players.

Methods: Eighty-eight Hong Kong professional football players (height, 177.

Stepwise Differentiation of Mesenchymal Stem Cells Augments Tendon-Like Tissue Formation and Defect Repair In Vivo.

Unlabelled: : Tendon injuries are common and present a clinical challenge, as they often respond poorly to treatment and result in long-term functional impairment. Inferior tendon healing responses are mainly attributed to insufficient or failed tenogenesis. The main objective of this study was to establish an efficient approach to induce tenogenesis of bone marrow-derived mesenchymal stem cells (BMSCs), which are the most common seed cells in tendon tissue engineering.

From the printer: Potential of three-dimensional printing for orthopaedic applications.

Three-dimensional (3D) printers can create complex structures based on digital models. The combination of medical diagnostic imaging with 3D printing has great potential in day-to-day clinics for patient-specific solutions and applications. In the musculoskeletal system, 3D printing is used to create custom-made implants, patient-specific instrumentation, and to regenerate tissues, in particular bone and cartilage.

Motion Task Selection for Kinematic Evaluation After Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Purpose: To examine the different motion tasks and the protocols used to objectively quantify dynamic stability in terms of knee kinematics at different stages of anterior cruciate ligament reconstruction (ACLR) recovery.

Methods: A systematic search was done using OVID in Embase, Cochrane Central Register of Controlled Trials, Medline, PsychINFO, and AMED. A combination of the following keywords and their variations were used: anterior cruciate ligament, motion tasks (e.