Skilled reaching test for shoulder function assessment in a rat model of rotator cuff tear: a pilot study.

BACKGROUND: Functional assessments are crucial to evaluate treatment outcomes in clinical and animal studies on rotator cuff injuries. While gait analysis is commonly used to assess animal models of rotator cuff tears, it is less relevant for human patients as the human shoulder is typically assessed in a non-weight-bearing condition. The present study introduces the skilled reaching test as a shoulder functional assessment tool for rats, which allows for evaluation without weight bearing. METHODS: In the control group, 8 male Sprague-Dawley rats received rotator cuff tear surgery without repair. In the rotator cuff repair group, 20 rats received rotator cuff repair at 4 weeks post rotator cuff tear. For the skilled reaching test, rats were trained to extend their forelimbs to fetch food pellets, and the number of trials, number of attempts and the success rate were recorded. The gait analysis and skilled reaching test were performed at baseline, 4 weeks post-tear, 1, 2, 4, and 8 weeks post-repair. The repeated measures analysis of variance was used to evaluate the effects of time on the shoulder function. The significance level was set at 0.05. RESULTS: The skilled reaching test required 216 h to conduct, while the gait analysis took 44 h. In the rotator cuff repair group, gait performance significantly deteriorated at 1 week post-repair and restored to 4 weeks post-tear levels at 4 weeks post-repair. Regarding the skilled reaching test, the number of attempts, number of trials and the success rate decreased at 1 week post-repair. Subsequently, there was a brief rebound in performance observed at 2 weeks post-repair, followed by a continued decline in the number of attempts and trials. By 8 weeks post-repair, only the success rate had restored to levels similar to those observed at 4 weeks post-tear. CONCLUSION: The skilled reaching test can detect functional deficiencies following rotator cuff tear and repair, while it requires high time and labour costs.

Establishment of a Mouse Degenerative Model of Patellar Tendinopathy with Upregulation of Inflammation.

There is no mouse model of patellar tendinopathy. This study aimed to establish a mouse inflammatory and degenerative patellar tendon injury model, which will facilitate research on patellar tendinopathy using advanced molecular tools including transgenic models. Collagenase at different doses (low dose (LD), medium dose (MD), high dose (HD)) or saline was injected over the mouse patellar tendon. At weeks 1, 2, 4, and 8 post-injection, the tendons were harvested for histology and further examined by micro-computed tomography (microCT) imaging at week 8. The optimal dose group and the saline group were further evaluated by immunohistochemical staining, gait pattern, and biomechanical properties. The histopathological score increased dose-dependently post-collagenase injection. Ectopic mineralization was observed and increased with collagenase dose. The LD group was selected for further analysis. The expression of IL-10, TNF-α, and MMP-1 significantly increased post-injection. The changes of limb idleness index (ΔLII) compared to preinjury state were significantly higher, while the ultimate load, stiffness, ultimate stress, and maximum Young's modulus were significantly lower in the LD group compared to the saline group. A mouse inflammatory degenerative model of patellar tendon injury resembling tendinopathy was established as indicated by the dose-dependent increase in tendon histopathology, ectopic calcification, decrease in biomechanical properties, and pain-associated gait changes.

Effects of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity: Study protocol for a randomized controlled trial.

Objective: This study aims to examine the comparative effects of 75 min of volume-matched once-weekly and thrice-weekly high-intensity interval training (HIIT) on body adiposity in adults with central obesity. Methods: This assessor-blinded, three-arm, randomized controlled trial will recruit 315 physically inactive adults with central obesity (aged ≥18 years, body mass index ≥23, waist circumference ≥90 cm for men and ≥80 cm for women). Participants will be randomly allocated to the once-weekly HIIT, thrice-weekly HIIT or usual care control group. Participants in the HIIT groups will receive weekly exercise training sessions for 16 weeks, prescribed either once or three times weekly. Each HIIT session will consist of a supervised program of four 4-min high-intensity intervals at 85%-95% peak heart rate (HRpeak) interspersed with 3-min active recovery intervals at 50%-70% HRpeak. Participants in the once-weekly HIIT group will perform the 25-min HIIT bout three times with a break between each 25-min HIIT bout. The usual care control group will receive bi-weekly health education classes. The outcome assessments will be conducted at baseline, 16 weeks (post-intervention) and 32 weeks (follow-up). The primary outcome will be total body adiposity assessed by dual-energy X-ray absorptiometry (DXA). The secondary outcome measures will include markers of cardiovascular and metabolic health (body composition, cardiorespiratory fitness, blood pressure, and blood lipids), mental health, cognitive performance, health-related quality of life, sleep quality, habitual physical activity, diet, medication, adverse events and adherence to the intervention. Impact of the project: The findings from this study are expected to consolidate the therapeutic efficacy of HIIT for the management of central obesity and inform the comparative compliance, feasibility and suitability of once-weekly and thrice-weekly HIIT as exercise strategies to manage obesity. In particular, the present study is expected to provide a novel perspective on the utility of low-frequency HIIT (i.e., once-weekly) as an effective and sustainable exercise strategy to tackle the obesity pandemic. The anticipated findings will hold substantial translational value by informing public health policies and enhancing exercise compliance in the physically inactive obese population. Trial registration: ClinicalTrials.gov (NCT04887454).

Positional MR imaging of normal and injured knees.

OBJECTIVES: This study uses a practical positional MRI protocol to evaluate tibiofemoral translation and rotation in normal and injured knees. METHODS: Following ethics approval, positional knee MRI of both knees was performed at 35° flexion, extension, and hyperextension in 34 normal subjects (mean age 31.1 ± 10 years) and 51 knee injury patients (mean age 36.4 ± 11.5 years, ACL tear n = 23, non-ACL injury n = 28). At each position, tibiofemoral translation and rotation were measured. RESULTS: Normal knees showed 8.1 ± 3.3° external tibial rotation (i.e., compatible with physiological screw home mechanism) in hyperextension. The unaffected knee of ACL tear patients showed increased tibial anterior translation laterally (p = 0.005) and decreased external rotation (p = 0.002) in hyperextension compared to normal knees. ACL-tear knees had increased tibial anterior translation laterally (p < 0.001) and decreased external rotation (p < 0.001) compared to normal knees. Applying normal thresholds, fifteen (65%) of 23 ACL knees had excessive tibial anterior translation laterally while 17 (74%) had limited external rotation. None (0%) of 28 non-ACL-injured knees had excessive tibial anterior translation laterally while 13 (46%) had limited external rotation. Multidirectional malalignment was much more common in ACL-tear knees. CONCLUSIONS: Positional MRI shows (a) physiological tibiofemoral movement in normal knees, (b) aberrant tibiofemoral alignment in the unaffected knee of ACL tear patients, and (c) a high frequency of abnormal tibiofemoral malalignment in injured knees which was more frequent, more pronounced, more multidirectional, and of a different pattern in ACL-tear knees than non-ACL-injured knees. KEY POINTS: • Positional MRI shows physiological tibiofemoral translation and rotation in normal knees. • Positional MRI shows a different pattern of tibiofemoral alignment in the unaffected knee of ACL tear patients compared to normal control knees. • Positional MRI shows a high prevalence of abnormal tibiofemoral alignment in injured knees, which is more frequent and pronounced in ACL-tear knees than in ACL-intact injured knees.

Comparative short-term effectiveness of non-surgical treatments for insertional Achilles tendinopathy: a systematic review and network meta-analysis.

BACKGROUND: The incidence of Achilles tendinopathy has risen over the past decades. Insertional Achilles tendinopathy is characterised by tissue degeneration of the Achilles tendon from its insertion in the calcaneus to up to 2 cm proximally. This clinical condition is accompanied by pain, loss of function and diminished exercise tolerance. Numerous conservative treatment modalities are available to participants with insertional Achilles tendinopathy, including eccentric exercises, extracorporeal shockwave therapy, laser therapy, cryotherapy, therapeutic ultrasound, and orthotics. Eccentric exercise and extracorporeal shockwave therapy may reduce pain in participants with non-calcified insertional Achilles tendinopathy. However, no specific treatment is recommended over another due to the low methodological quality of trials. Given the lack of standard or preferred non-surgical treatment and the potential risks of surgical treatment, there is an imminent need to reassess different non-surgical treatments based on the newest evidence. Thus, this systematic review aims to evaluate the clinical effectiveness of the various non-surgical treatments for insertional Achilles tendinopathy. METHODS: AMED EBSCOhost, CINAHL, EBSCOhost, EMBASE, PEDro, PubMed, Web of Science, and Clinicaltrials.gov were searched from 1992 to 14th October 2022, randomised controlled trials of adults with insertional Achilles tendinopathy investigating non-surgical treatments compared with each other or no treatment, placebo/sham control. Two reviewers independently screened and extracted the data. Random effects of network meta-analysis immediately after treatments were used to report comparative treatment effects. The surface under the cumulative ranking probabilities was calculated to assess the relative ranking of treatments. RESULTS: Nine trials (total n = 464 participants) were included. This review recommended the combination of eccentric exercise and soft tissue therapy to manage insertional Achilles tendinopathy. With the highest SUCRA values of 84.8, and the best mean rank of 1.9, Eccentric exercise plus soft tissue treatment ranked as the most effective treatment for short-term pain. CONCLUSIONS: This is the first NMA of non-surgical treatment focusing on short-term pain control for IAT which eccentric exercise plus soft-tissue therapy was found to be the most effective treatment combination. However, the overall confidence in non-surgical treatments from all included trials was very low. No recommendation of the best treatment option can be made from this review.

Assessments of early patellofemoral joint osteoarthritis features after anterior cruciate ligament reconstruction: a cross-sectional study.

BACKGROUND: Persistent anterior knee pain and subsequent patellofemoral joint (PFJ) osteoarthritis (OA) are common symptoms after anterior cruciate ligament reconstruction (ACLR). Quadriceps weakness and atrophy is also common after ACLR. This can be contributed by arthrogenic muscle inhibition and disuse, caused by joint swelling, pain, and inflammation after surgery. With quadriceps atrophy and weakness are associated with PFJ pain, this can cause further disuse exacerbating muscle atrophy. Herein, this study aims to identify early changes in musculoskeletal, functional and quality of health parameters for knee OA after 5 years of ACLR. METHODS: Patients treated with arthroscopically assisted single-bundle ACLR using hamstrings graft for more than 5 years were identified and recruited from our clinic registry. Those with persistent anterior knee pain were invited back for our follow-up study. For all participants, basic clinical demography and standard knee X-ray were taken. Likewise, clinical history, symptomatology, and physical examination were performed to confirm isolated PFJ pain. Outcome measures including leg quadriceps quality using ultrasound, functional performance using pressure mat and pain using self-reported questionnaires (KOOS, Kujala and IKDC) were assessed. Interobserver reproducibility was assessed by two reviewers. RESULTS: A total of 19 patients with unilateral injury who had undergone ACLR 5-years ago with persistent anterior knee pain participated in this present study. Toward the muscle quality, thinner vastus medialis and more stiffness in vastus lateralis were found in post-ACLR knees (p < 0.05). Functionally, patients with more anterior knee pain tended to shift more of their body weight towards the non-injured limb with increasing knee flexion. In accordance, rectus femoris muscle stiffness in the ACLR knee was significantly correlated with pain (p < 0.05). CONCLUSION: In this study, it was found that patients having higher degree of anterior knee pain were associated with higher vastus medialis muscle stiffness and thinner vastus lateralis muscle thickness. Similarly, patients with more anterior knee pain tended to shift more of their body weight towards the non-injured limb leading to an abnormal PFJ loading. Taken together, this current study helped to indicate that persistent quadriceps muscle weakness is potential contributing factor to the early development of PFJ pain.

Effects of Gluteus Medius and Biceps Femoris Stimulation on Reduction of Knee Abduction Moment During a Landing Task.

Anterior cruciate ligament injury prevention should focus primarily on reduction of the knee abduction moment (KAM) in landing tasks. Gluteus medius and hamstring forces are considered to decrease KAM during landing. The effects of different muscle stimulations on KAM reduction were compared using 2 electrode sizes (standard 38 cm2 and half size 19 cm2) during a landing task. Twelve young healthy female adults (22.3 [3.6] y, 1.62 [0.02] m, 50.2 [4.7] kg) were recruited. KAM was calculated under 3 conditions of muscle stimulation (gluteus medius, biceps femoris, and both gluteus medius, and biceps femoris) using 2 electrode sizes, respectively versus no stimulation during a landing task. A repeated-measures analysis of variance determined that KAM differed significantly among stimulation conditions and post hoc analysis revealed that KAM was significantly decreased in conditions of stimulating either the gluteus medius (P < .001) or the biceps femoris (P < .001) with the standard electrode size, and condition of stimulating both gluteus medius and biceps femoris with half-size electrode (P = .012) when compared with the control condition. Therefore, stimulation on the gluteus medius, the biceps femoris, or both muscles could be implemented for the examination of anterior cruciate ligament injury potential.

Large lateral tibial slope and lateral-to-medial slope difference are risk factors for poorer clinical outcomes after posterolateral meniscus root tear repair in anterior cruciate ligament reconstruction.

BACKGROUND: Meniscus root tear is an uncommon but detrimental injury of the knee. Hoop stress is lost during meniscus root tear, which can lead to excessive tibiofemoral contact pressure and early development of osteoarthritis. Posterolateral meniscus root tears (PLRT) are more commonly associated with anterior cruciate ligament (ACL) tears. As the lateral compartment is less congruent than the medial compartment, it is more susceptible to a shearing force, which is increased in the ACL-deficient knee. In accordance with the compressive axial load, the increase in the tibial slope would generate a greater shearing force. The additional lateral compartment mobility caused by ACL tear should be reduced after ACL reconstruction (ACLR). However, there is a lack of evidence to conclude that ACLR can sufficiently limit the effect of large tibial slope (LTS) on the healing after PLRT repair. This study aimed to evaluate whether a steep LTS would be a risk factor for poorer clinical outcomes after PLRT repair concomitant with ACLR. METHODS: In this retrospective study, a chart review was conducted to identify patients with concomitant unilateral primary ACLR and PLRT repair. Patients with a partial tear or healed tear were excluded. Postoperative MRI and clinical assessments were performed at a mean follow up of 35 months. MRI data was used to measure the LTS, medial tibial slope (MTS), coronal tibial slope (CTS), the lateral-to-medial slope difference (LTS-MTS) and meniscus healing and extrusion. Functional outcomes were evaluated by patient-reported outcomes (International Knee Documentation Committee [IKDC], Lysholm and Tegner scores) and KT-1000 arthrometer assessment. Interobserver reproducibility was assessed by two reviewers. RESULTS: Twenty-five patients were identified for the analysis. Patients with larger LTS and larger LTS-MTS differences were shown to be correlated with poorer IKDC scores after surgery (R = -0.472, p = 0.017 and R = -0.429, p = 0.032, respectively). Herein, patients with LTS ≥ 6° or LTS-MTS ≥ 3° demonstrated poorer IKDC scores. CONCLUSION: A large LTS (≥ 6°) and a large difference of LTS-MTS (≥ 3°) were shown to be risk factors for poorer functional and radiological outcomes for PLRT repair in patients after ACLR. Clinically, closer monitoring and a more stringent rehabilitation plan for patients with LTS ≥ 6° or LTS-MTS ≥ 3° would be recommended.

Prophylaxis for preventing venous thromboembolism in knee arthroscopy and soft tissue reconstruction: consensus statements from an international panel of experts.

PURPOSE: There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines like ones for trauma surgery and arthroplasty do not exist and the published literature is limited to case reports with a few society guidelines. Given this lack of consensus, we conducted a modified Delphi questionnaire of international experts to provide recommendations on this topic. METHODS: The consensus statements were generated using an anonymised 3 round modified Delphi questionnaire, sent to an international panel of 38 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics with measures like mode, median and box plots. Feedback was provided to all panelists based on responses from the previous rounds to help generate the consensus. RESULTS: Six consensus statements were generated after the three rounds of Delphi. Patient factors, prolonged surgery duration and family history of thrombogenic events emerged as the main points to be taken into consideration for prophylaxis. CONCLUSION: It was established through this study, that there exists a select group of patients undergoing arthroscopic surgery that justify the usage of VTE prophylaxis. The expert responses to most of the questions in different scenarios favoured usage of VTE prophylaxis based on patient factors like advanced age, past history of VTE, smoking, oral contraceptive use etc. LEVEL OF EVIDENCE: Level V.

Effects of one-year once-weekly high-intensity interval training on body adiposity and liver fat in adults with central obesity: Study protocol for a randomized controlled trial.

Objective: This study aims to examine the effects of one-year, once-weekly high-intensity interval training (HIIT) on body adiposity and liver fat in adults with central obesity. Methods: One-hundred and twenty adults aged 18-60 years with central obesity (body mass index ≥25, waist circumference ≥90 cm for men and ≥80 cm for women). This is an assessor-blinded randomized controlled trial. Participants will be randomly assigned to the HIIT group or the usual care control group. Each HIIT session will consist of 4 × 4-min bouts at 85%-95% maximal heart rate, interspersed with 3-min bouts at 50%-70% maximal heart rate. The HIIT group will complete one session per week for 12 months, whereas the usual care control group will receive health education. The primary outcomes of this study are total body adiposity and intrahepatic triglyceride content. The secondary outcomes include abdominal visceral adipose tissue, subcutaneous adipose tissue, body mass index, waist circumference, hip circumference, cardiorespiratory fitness, lean body mass, bone mineral density, blood pressure, fasting blood glucose, insulin, triglycerides, glycated hemoglobin, cholesterol profile, liver function enzymes, medications, adherence to exercise, adverse events, quality of life, and mental health. Outcome measure will be conducted at baseline, 12 months (post-intervention), and 24 months (one-year follow-up). Impact of the project: This study will explore the benefits of long-term once-weekly HIIT with a follow-up period to assess its effectiveness, adherence, and sustainability. We expect this intervention will enhance the practical suitability of HIIT in inactive adults with central obesity, and provide insights on low-frequency HIIT as a novel exercise option for the management of patients with central obesity and liver fat. Trial registration: ClinicalTrials.gov (NCT03912272) registered on 11 April 2019.

Bilateral impairments of quadriceps neuromuscular function occur early after anterior cruciate ligament injury.

The study aimed to investigate the impairments in quadriceps neuromuscular function, including strength, rate of torque development (RTD) and activation failure (QAF) early after an ACL injury. A cross-sectional study was conducted. Thirty physically active patients with a primary ACL injury within three months, aged 18 to 40 years old, and who were scheduled for ACL reconstruction were included. Thirty matched healthy controls were also recruited. All the outcomes were measured on an isokinetic dynamometer with knee flexion at 45°. Quadriceps strength was measured by maximal voluntary isometric contractions (MVIC). Early (RTD0-50) and late (RTD100-200) phases of RTD were retrieved from the MVIC test from 0 to 50 ms and 100-200 ms, respectively. QAF was quantified by the central activation ratio (CAR) measured by superimposed burst technique. The results of Mann-Whitney U test showed that compared with the healthy limbs, the injured limbs of the ACL group showed lower quadriceps strength (P < 0.001), RTD0-50 (P < 0.001) and RTD100-200 (P < 0.001); the uninjured limbs showed lower quadriceps strength (P = 0.009), RTD0-50 (P = 0.006) as well as greater QAF (P = 0.010). To conclude, bilateral quadriceps suffered from neuromuscular impairments early after an ACL injury.

Associations of patient characteristics, rate of torque development, voluntary activation of quadriceps with quadriceps strength, and knee function before anterior cruciate ligament reconstruction.

Good preoperative knee function (KF) and quadriceps strength (QS) relate to good prognoses after anterior cruciate ligament reconstruction (ACLR). This study aimed to investigate the associations between patient characteristics, rate of torque development (RTD), voluntary activation (VA) of the quadriceps against preoperative KF and QS. A cross-sectional study was conducted. Forty patients with a primary, unilateral ACL injury who had finished the preoperative rehabilitation and scheduled for an ACLR were included. KF was evaluated using the International Knee Documentation Committee score. QS was measured by maximal voluntary isometric contractions. RTD was divided into the early (RTD0-50) and the late (RTD100-200) phases. Quadriceps VA was measured using the superimposed burst technique. Our results showed that patients with poor preoperative KF had more deficits in RTD0-50 (P = 0.025), higher BMI(P = 0.043), and more meniscus injuries (MI) (P = 0.001) than those with good KF. Patients with asymmetrical QS showed lower BMI (P = 0.020) and shorter time from injury (TFI) (P = 0.027) than those with symmetrical QS. Additionally, a higher pre-injury Tegner score combined with greater RTD100-200 contributed to greater QS on the injured limb (R2 = 0.357, P = 0.001). To conclude, BMI, TFI, concomitant MI, pre-injury physical activity level, and quadriceps RTD are related to QS and KF before ACLR.

Knee wobbling during the single-leg-squat-and-hold test reflects dynamic knee instability in patients with anterior cruciate ligament injury.

We propose using the single-leg squat-and-hold (SLSH) task with kinematic analysis to objectively measure dynamic knee stability after anterior cruciate ligament (ACL) injury. There are three objectives of this study: to compare the knee kinematics of ACL-deficient patients and healthy controls by capturing knee wobbling during the SLSH task, to detect kinematic changes after ACL reconstruction, and to correlate the kinematic variables with self-reported knee function. Twenty-five ACL-deficient participants and 18 healthy matched participants were recruited. The knee kinematics involving both the magnitudes and frequency of motion fluctuation was captured during SLSH by 3D motion analysis system (Vicon). Compared to the limbs of the control participants, the ACL involved limbs exhibited a greater range of flexion-extension (4.33 ± 1.96 vs. 2.73 ± 1.15; p = 0.005) and varus-valgus (2.52 ± 0.99 vs. 1.36 ± 0.42; p < 0.001). It also inhibited higher frequency of flexion-extension (4.87 ± 2.55 vs. 2.68 ± 1.23; p = 0.003) and varus-valgus (3.83 ± 2.59 vs. 1.42 ± 0.55; p < 0.001). The range of flexion-extension (4.50 ± 2.24 vs. 2.90 ± 1.01; p = 0.018), frequency of flexion-extension (4.58 ± 2.53 vs. 3.05 ± 1.80; p = 0.038) and varus-valgus (3.46 ± 2.11 vs. 1.80 ± 1.23; p = 0.022) was reduced after ACL reconstruction. Increased frequency of knee varus-valgus was correlated with lower IKDC score (r = -0.328; p = 0.034). Knee wobbling was more prominent in ACL-deficient patients, which was associated with poor knee function. SLSH task with kinematic analysis appears to be a potential assessment method for monitoring dynamic knee stability after ACL injury.

Tendon-derived extracellular matrix induces mesenchymal stem cell tenogenesis via an integrin/transforming growth factor-ß crosstalk-mediated mechanism.

Treatment of tendon injuries is challenging. To develop means to augment tendon regeneration, we have previously prepared a soluble, low immunogenic (DNA-free), tendon extracellular matrix fraction (tECM) by urea extraction of juvenile bovine tendons, which is capable of enhancing transforming growth factor-ß (TGF-ß) mediated tenogenesis in human adipose-derived stem cells (hASCs). Here, we aimed to elucidate the mechanism of tECM-driven hASC tenogenic differentiation in vitro, focusing on the integrin and TGF-ß/SMAD pathways. Our results showed that tECM promoted hASC proliferation and tenogenic differentiation in vitro based on tenogenesis-associated markers. tECM also induced higher expression of several integrin subunits and TGF-ß receptors, and nuclear translocation of p-SMAD2 in hASCs. Pharmacological inhibition of integrin-ECM binding, focal adhesion kinase (FAK) signaling, or TGF-ß signaling independently led to compromised pro-tenogenic effects of tECM and actin fiber polymerization. Additionally, integrin blockade inhibited tECM-driven TGFBR2 expression, while inhibiting TGF-ß signaling decreased tECM-mediated expression of integrin α1, α2, and ß1 in hASCs. Together, these findings suggest that the strong pro-tenogenic bioactivity of tECM is regulated via integrin/TGF-ß signaling crosstalk. Understanding how integrins interact with signaling by TGF-ß and/or other growth factors (GFs) within the tendon ECM microenvironment will provide a rational basis for an ECM-based approach for tendon repair.

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

Purpose: 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.Materials and methods: Thirty-three rats underwent ACLR. Tendon grafts were harvested at week 1 (necrosis), 2 (proliferation), or 12 (ligamentization) post-operation for histological examination (n = 3), or for isolation of graft-derived cells (n = 8) for flow cytometry, proliferation assay, cell invasion assay, measurement of gene expression related to matrix remodeling (Col1A1, Col3A1, MMP1, tissue inhibitor of marix metalloproteinase 1 (TIMP1), and MMP13) and total MMP activities.Results: Increased cellularity in tendon graft was contributed by active cell proliferation and migration at week 2 post-operation, while decreased cellularity were paralleled by increased apoptosis at week 12. All genes measured (Col1A1, Col3A1, MMP1, TIMP1, and MMP13) increased significantly in week 2 cells compared to week 1 cells. MMP1 expression subsided at week 12, while MMP13 expression kept increasing till 12 weeks post-operation. Total MMP activities was 3-fold higher in cultured graft-derived cells from week 2 as compared to cells from week 12. Two distinct processes of graft remodeling were identified, characterized by increased MMP1 expression with cell proliferation and increased MMP13 expression with cell apoptosis.Conclusions: Unfavorable matrix remodeling during the proliferation phase is found with increased MMP1, while remodeling leading to ligamentization is associated with increased MMP13 expression.

Screening for laterally deviated plantar pressure during stance using the Cumberland ankle instability tool and anthropometric measures.

This study developed a method that predicts laterally deviated plantar pressure during stance by lower limb anthropometrics and self-reported ability to stop an ankle which has started to roll over. Thirty-two males ran on a treadmill for 2 minutes at 11 km/h. Foot pressure data were collected by a pressure insole system for classifying the participants as medial or lateral strikers. Cumberland Ankle Instability Tool score, Tegner Activity Scale score, foot arch height, active and passive ankle and knee range of motion, bi-malleolar width, foot length, foot width and calf circumference were measured. Binary logistic regressions were performed to produce a model which estimated if an individual showed laterally deviated foot pressure during stance. The model utilized the score of Cumberland Ankle Instability Tool Question 8, active and passive knee joint external rotation, height, body mass and bimalleolar width (explained variance of 47.3%, p = 0.037), producing a sensitivity of 71.4% and a specificity of 54.5%. A validation trial on another 15 runners reported a 73.3% accuracy in prediction if they are medial or lateral strikes.

A systematic review of inflammatory cells and markers in human tendinopathy.

BACKGROUND: This article systematically reviews the current evidence regarding inflammation in Tendinopathy with the aim to increase understanding of a potential common pathophysiology. METHODS: Following the PRISMA statements, the terms: (tendinopathy OR (tendons AND rupture)) AND (inflammation OR (inflammation AND cells) OR immune system OR inflammation mediators OR bacteria) were used. One thousand four hundred thirty-one articles were identified which was screened down to 53. RESULTS: 39/53 studies mentioned inflammatory cells but had contradicting conclusions. Macrophages were the most common cell type and inflammatory markers were detectable in all the articles which measure them. CONCLUSIONS: The included studies show different conclusions, but this heterogeneity is not unexpected since the clinical criteria of 'tendinopathy' encompass a huge clinical spectrum. Different 'tendinopathy' conditions may have different pathophysiology, and even the same clinical condition may be at different disease stages during sampling, which can alter the histological and biochemical picture. Control specimen sampling was suboptimal since the healthy areas of the pathological-tendon may actually be sub-clinically diseased, as could the contralateral tendon in the same subject. Detection of inflammatory cells is most sensitive using immunohistochemistry targeting the cluster of differentiation markers, especially when compared to the conventional haematoxylin and eosin staining methods. The identified inflammatory cell types favour a chronic inflammatory process; which suggests a persistent stimulus. This means NSAID and glucocorticoids may be useful since they suppress inflammation, but it is noted that they may hinder tendon healing and cause long term problems. This systematic review demonstrates a diversity of data and conclusions in regard to inflammation as part of the pathogenesis of Tendinopathy, ranging from ongoing or chronic inflammation to non-inflammatory degeneration and chronic infection. Whilst various inflammatory markers are present in two thirds of the reviewed articles, the heterogenicity of data and lack of comparable studies means we cannot conclude a common pathophysiology from this systematic review.

Is Pre-operative Quadriceps Strength a Predictive Factor for the Outcomes of Anterior Cruciate Ligament Reconstructions.

Persistent quadriceps weakness prevents patients from returning to sports after ACL reconstruction. Pre-operative quadriceps strength was indicated as an important factor for the outcomes of ACL reconstruction. However, the existing evidence is controversial. Therefore, this systematic review was conducted to summarize and evaluate the relationship between pre-operative quadriceps strength and the outcomes following ACL reconstruction, and to summarize the predictive value of pre-operative quadriceps strength for satisfactory post-operative outcomes. Pubmed, WOS, Embase, CINAHL and SportDiscus were searched to identify eligible studies according to PRISMA guidelines. Relevant data was extracted regarding quadriceps strength assessment methods, pre-operative quadriceps strength, participants treatment protocols, post-operative outcomes, follow-up time points and the relevant results of each individual study. Twelve cohort studies (Coleman methodology score: 62±10.4; from 44-78) with 1773 participants included. Follow-up period ranged from 3 months to 2 years. Moderate evidence supports the positive association between pre-operative quadriceps strength and post-operative quadriceps strength; weak evidence supports the positive association between pre-operative quadriceps strength and post-operative functional outcomes. By now, there is no consensus on the predictive value of pre-operative quadriceps strength for achieving satisfactory quadriceps strength after ACLR. To conclude, pre-operative quadriceps strength should be taken into consideration when predict patient recovery of ACLR.

Reverse anterolateral drawer test is more sensitive and accurate for diagnosing chronic anterior talofibular ligament injury.

PURPOSE: To diagnose chronic anterior talofibular ligament (ATFL) injury, three different physical examinations were compared: the anterior drawer test (ADT), the anterolateral drawer test (ALDT), and the reverse anterolateral drawer test (RALDT). METHODS: A total of 72 ankles from potential ATFL-injured patients and the normal population were included and examined using the ADT, ALDT, and RALDT by two examiners without knowing the injury histories of any of the participants. Ultrasound examination was then applied as the gold standard to divide the ankles into the ATFL-injured group and the control group. The sensitivity (Se), specificity (Sp), false negative rate (FNR), false positive rate (FPR), accuracy, κ value, and p value of the two examiners' diagnoses were calculated to assess the diagnostic ability of each examination. RESULTS: There were 38 ankles in the injured group and 34 ankles in the control group. No significant difference was found between the two groups in terms of gender, age, body mass index (BMI), and included ankles. In the ADT and ALDT groups, the specificity reached one, while the sensitivity was relatively low (0.053 and 0.477 for the junior examiner and 0.395 and 0.500 for the senior examiner). In the RALDT, both the sensitivity and specificity were greater than 85% (0.868 and 0.912 for the senior examiner and 0.921 and 0.882 for the junior examiner). The κ value of the RALDT (0.639) was higher than that of the ALDT (0.528) and the ADT (0.196), whereas all the p values were less than 0.05. CONCLUSION: The ADT and ALDT are valuable physical tests to assess ATFL injuries. Compared with the traditional ADT and ALDT, however, the RALDT is more sensitive and accurate in diagnosing chronic ATFL injuries. LEVEL OF EVIDENCE: II (diagnostic).

Arthroscopic Lateral Soft Tissue Release for Hallux Valgus.

Release of the tight lateral soft tissue is an important procedure during surgery for hallux valgus. The authors describe an arthroscopic assisted lateral soft tissue release technique that is minimally invasive and easy to perform, while also providing precise visualization of the released structures.