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.

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.

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.

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.

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.

A Systematic Review of Anterior Cruciate Ligament Femoral Footprint Location Evaluated by Quadrant Method for Single-Bundle and Double-Bundle Anatomic Reconstruction.

PURPOSE: To unravel the standard position of anterior cruciate ligament (ACL) femoral origin and deduce practical arthroscopic localization and postsurgical evaluation method. METHODS: Two independent reviewers searched PubMed using the terms ACL, footprint, femur, etc. We included studies published since January 1, 2000, in which the results were measured by Bernard's quadrant method. This method consists of 4 distances, including total diameter of lateral condyle along Blumensaat's line (distance t), maximum intercondylar notch height (distance h), distance from center of footprint to proximal border (distance x), and distance from center of footprint to Blumensaat's line (distance y). The data of included studies were combined to calculate theoretical centers and standard area for both ACL as a whole bundle and as anteromedial (AM) and posterolateral (PL) bundles individually. Finally, we translated the combined data to arthroscopic localization and postsurgical evaluation. RESULTS: A total of 13 studies were included. The theoretical centers of ACL as a whole bundle is 28.4% ± 5.1% (x) of distance t and 35.7% ± 6.9% (y) of distance h, whereas AM bundle is 24.2% ± 4%, 21.6% ± 5.2% (x, y) and PL bundle is 32.8% ± 4.7%, 46.7% ± 4.9% (x, y), respectively. The standard area of ACL footprint is a circle with a center of 27.53%, 35.85% (x, y), and a radius of 4.58%, 9.2% (x, y), respectively. Translation of combined data shows that under arthroscopy, for single-bundle ACL reconstruction, the midpoint of distance from border of proximal to distal articular cartilage is the center of anatomic femoral socket. CONCLUSIONS: Combined data unravel the standard position of ACL femoral origin. It can be used by clinicians to localize anatomic tunnel both in surgery and postsurgical evaluation. For single-bundle ACL reconstruction, the midpoint of lateral femoral condyle corresponds to anatomic socket. LEVEL OF EVIDENCE: Level V, systematic review of anatomic studies.

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.g., jump, hop, gait), and stability. The inclusion criteria were as follows: (1) ACLR subjects were recruited, (2) at least 1 motion task was performed and kinematics data were recorded, and (3) uninjured subjects or the contralateral uninjured limbs were included as a control group. Exclusion criteria were as follows: (1) non-English language publications, (2) retrospective studies and review articles, (3) animal studies, and (4) cadaveric studies. RESULTS: The search returned 2,195 studies, and 56 were included in this review according to the criteria. A total of 1,086 ACLR subjects were included. Pivoting, landing, walking, running, stair negotiation, and squats were assessed using optoelectronic motion capture, electrogoniometry, or video-radiography. CONCLUSIONS: The appropriate selection of motion tasks is an integral factor in dynamic stability testing as it evokes different kinematic outcomes in relation to the different stages of ACLR recovery. Stair negotiation and landing tasks are best performed during the early stages of recovery, and landing and pivoting are recommended 6 months after ACLR surgery. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.

Biomimetic triphasic silk fibroin scaffolds seeded with tendon-derived stem cells for tendon-bone junction regeneration.

The regeneration of tendon and bone junctions (TBJs), a fibrocartilage transition zone between tendons and bones, is a challenge due to the special triphasic structure. In our study, a silk fibroin (SF)-based triphasic scaffold consisting of aligned type I collagen (Col I), transforming growth factor ß (TGF-ß), and hydroxyapatite (HA) was fabricated to mimic the compositional gradient feature of the native tendon-bone architecture. Rat tendon-derived stem cells (rTDSCs) were loaded on the triphasic SF scaffold, and the high cell viability suggested that the scaffold presents good biocompatibility. Meanwhile, increased expressions of tenogenic-, chondrogenic-, and osteogenic-related genes in the TBJs were observed. The in vivo studies of the rTDSC-seeded scaffold in a rat TBJ rupture model showed tendon tissue regeneration with a clear transition zone within 8 weeks of implantation. These results indicated that the biomimetic triphasic SF scaffolds seeded with rTDSCs have great potential to be applied in TBJ regeneration.

Effect of graft tensioning on mechanical restoration in a rat model of anterior cruciate ligament reconstruction using free tendon graft.

PURPOSE: Initial graft tensioning is important in anterior cruciate ligament reconstruction (ACLR), but its effect on graft healing is still not clear. Since all previous animal studies on graft tensioning used bone-patellar tendon-bone, this study aimed to investigate the effect of initial graft tensioning on ACLR using tendon graft. METHODS: Fifty-five Sprague-Dawley rats underwent ACLR using flexor digitorum longus tendon graft. A constant force of 2 or 4 N was applied during graft fixation. At 0, 2, and 6 weeks, knee samples were harvested (n = 6) for static knee laxity test and graft pull-out test. Histological examination was performed at 2 and 6 weeks post-injury (n = 4). RESULTS: At time zero, knee laxity was restored by ACLR with 2 or 4 N tensioning as compared to ACL-deficient group (p < 0.001), and the 4 N group exhibited a better restoration as compared to 2 N group (p = 0.031). At week 2 post-operation, the 4 N group still exhibited a better restoration in knee laxity (p = 0.001) and knee stiffness (p = 0.002) than the 2 N group; the graft pull-out force (p = 0.032) and stiffness (p = 0.010) were also higher. At week 6 post-operation, there was no significant difference between the 2 and 4 N group in knee laxity and graft pull-out strength. Histological examination showed that the beneficial effect of higher initial graft tension may be contributed by maintenance of graft integrity at mid-substance and reduction in adverse peri-graft bone changes in the femoral tunnel region. CONCLUSIONS: A higher initial graft tension favours the restoration of knee laxity and promotes graft healing in ACLR using free tendon graft in the rat model.

Clinical effectiveness of pulsed electromagnetic field therapy as an adjunct treatment to eccentric exercise for Achilles tendinopathy: a randomised controlled trial.

BACKGROUND: The Achilles tendon is the largest and strongest tendon in the human body. Achilles tendinopathy (AT) is a common clinical problem with Achilles overuse. Eccentric exercise is often used as an initial treatment for these patients. Most patients with AT experienced moderate to severe pain, limiting the incentive to perform eccentric exercise. It is difficult for them to complete eccentric exercise for 3 months consecutively to obtain significant improvements. Using PEMF as an adjunct, there could be immediate pain relief and improved response to eccentric exercise by modulating the mechanical properties of the Achilles tendon. Participants may experience less pain while performing eccentric exercises to increase compliance with the rehabilitation programme. METHODS: This prospective randomised double-blinded, placebo-controlled trial aims to investigate the treatment effects of PEMF for participants with AT. All participants are randomised into two groups: the intervention group (n = 20; active PEMF treatment and eccentric exercise) and the control group (n = 20; sham treatment and eccentric exercise). Researchers perform self-reported, functional and ultrasonographic outcomes during baseline assessment, 4 weeks, 8 weeks follow-ups, and 3 and 6 months follow-ups after the commencement of the PEMF treatment. DISCUSSION: AT is a common clinical condition affecting athletes and sedentary populations. It is essential to investigate treatment adjuncts to improve rehabilitation outcomes for these patients. This trial may demonstrate the effectiveness of PEMF in relieving pain, improving function, and restoring mechanical changes of the tendon in participants with AT. TRIAL REGISTRATION: ClinicalTrials.gov NCT05316961. Registered on 7th April 2022.

Application of suture anchors for a clinically relevant rat model of rotator cuff tear.

Current rat model of rotator cuff (RC) tear could not mimic the suture anchor (SA) repair technique in the clinical practice. We designed a novel SA for RC repair of rats to establish a clinically relevant animal model. Small suture anchors that fit the rat shoulder were assembled. 60 rats were assigned to the transosseous (TO) repair group or SA repair group (n = 30/group). Micro-computed tomography (Micro-CT) scanning, biomechanical test and histological analysis were implemented at 2, 4, and 8-week post-repair. The failure load and stiffness in the SA group were significantly higher than those of TO group at 4-week post-repair. Micro-computed tomography analysis showed the bone mineral density and trabecular thickness of the SA group were significantly lower than those of TO group. The SA group showed a better insertion continuity at 4-week post-repair compared to TO group. No significant difference in gait parameters was found between groups. Therefore, SA repair is applicable for the rat model of RC tears. The SA repair achieved superior RC tendon healing, but more extensive initial bone damage compared to TO repair, while the shoulder function was comparable. This model could replicate the current repair technique in the clinical situation and be considered for future preclinical studies on healing enhancement for RC tears. Statement of Clinical Significance: With high clinical relevance, this model may facilitate the translation from an animal study into clinical trials.

Vitamin D deficiency in athletes: Laboratory, clinical and field integration.

Vitamin D deficiency is highly prevalent in athletes. Increased utilisation and storage depletion may be key contributing factor. We found a higher prevalence of vitamin D inadequacy (deficiency/ insufficiency) in power than endurance sport athletes, which may be related to vitamin D utilisation and reserve in skeletal muscles.

Timing of postoperative weightbearing in the treatment of traumatic chondral injuries of the knee in athletes - A systematic review of current concepts in clinical practice.

BACKGROUND: Surgery aims to stimulate healing and enable a safe return to sport in athletes with symptomatic cartilage lesions of the knee. Timing of postoperative weightbearing is crucial, balancing a stimulation of the healing and avoiding reinjury.To explore current concepts of timing to partial and full weightbearing and rate of return to sport in athletes after articular cartilage surgery of the knee.Systematic Review of studies with level of evidence I-III. METHODS: Four databases (Pubmed, Web of Science, Scopus and Embase) were searched using a predetermined keyword strategy. Two independent reviewers screened results according to inclusion and exclusion criteria. Modified Coleman Methodology Score (mCMS) was used for the quality assessment. RESULTS: 5294 records were found. Data from ten studies was extracted after duplicate removal, title and abstract screening and full-text evaluation. Eight of the ten studies included a detailed rehabilitation protocol, including 336 out of a total athletic population of 401. 62% began partial weightbearing (PWB) 1-2 weeks postoperatively, while 38% began within 3-4 weeks. The studies that had a later PWB all returned to full weightbearing (FWB) within 6-8 weeks. One study with early PWB returned to early FWB, while the other two returned 10-12 weeks postoperatively. "Return to Sport" (RTS) was the most common reported outcome measure, with most studies reporting RTS at 80% or higher. CONCLUSION: There is no clear evidence that the timing of weightbearing (WB) affects the outcome and return to sport in athletes after surgery for focal full-thickness cartilage lesions of the knee. On the other hand, there seems to be no adverse effects in adopting an early WB strategy, currently defined differently by different authors. Further studies directly comparing the timing of WB for specific surgical procedures in athletes and with relevant control groups is recommended. There is a need for a consensus in regard to more exactly defining "early" vs "late" weightbearing in relation to a universal and precisely defined state of healing.

Cross-Cultural Adaptation of Chinese Victorian Institute of Sports Assessment-Achilles (VISA-A) Questionnaire for Achilles Tendinopathy.

Background: Victorian Institute of Sports Assessment (VISA-A) is a patient-reported outcome for assessing symptoms severity associated with Achilles tendinopathy (AT). It is a valid and reliable tool that has been used widely for measuring and monitoring treatment outcomes for AT. This clinical measurement study aims to develop a Chinese version of the VISA-A questionnaire. The study objective is to adapt the VISA-A questionnaire cross-culturally and assess its psychometric property for Chinese-speaking individuals. Methods: VISA-A was translated and adapted cross-culturally according to international guidelines for self-reported questionnaires. During the establishment of Chinese VISA-A, there are 5 stages involved in the creation process, including translation, synthesis, reverse translation, review, and pretesting, which are performed by professionals in various fields, including orthopaedic surgeons, physiotherapists, and professional translators. Results: A total of 60 participants were recruited to complete the Chinese VISA-A and 36-Item Short Form Health Survey (SF-36) questionnaires. The overall test-retest reliability was 0.98 (intraclass correlation coefficient = 0.97-0.99). The correlation between Chinese VISA-A and physical function subscale (r = 0.70) was strong and statistically significant. There were moderate correlations between Chinese VISA-A, limitations to role of physical function subscale (r = 0.30), and bodily pain subscale (r = 0.42), which were also statistically significant. There were statistically significant differences in Chinese VISA-A scores between healthy control and pathologic group (P < .001), at-risk group, and pathologic group (P < .001) respectively. Conclusion: Chinese VISA-A demonstrated good reliability and validity for measuring symptom severity in patients with AT. Chinese VISA-A can be recommended as a self-reported measure for monitoring symptoms severity and treatment progress of patients with Achilles tendinopathy.Level of Evidence: Level II, cohort study.

Platelet-rich plasma pretreatment protects anterior cruciate ligament fibroblasts correlated with PI3K-Akt-mTOR pathway under hypoxia condition.

Background: /Objective: Biological factors such as platelet-rich plasma (PRP) combined with anterior cruciate ligament (ACL) primary repair technology are used to treat ACL injury. However, the protective mechanism of PRP for ACL fibroblasts under hypoxia condition is still unknown. The aim of this study was to investigate the protective effect of PRP on ACL fibroblasts under hypoxia condition and illustrate the mechanism of PRP regulating the ACL fibroblasts under hypoxia condition. Methods: The cells were divided into three groups: control group, hypoxia group and PRP pretreatment group. Lethal dose (LD) 50 for hypoxia induction time and the maximum efficacy of PRP concentration were confirmed by CCK-8 assay. The ability of cell apoptosis, cell proliferation, and cell migration were tested by flow cytometry, scratch assay and transwell assay, respectively. Extracellular matrix (ECM) synthesis and hypoxia-inducible factor 1α (HIF-1α) were identified by immunofluorescence staining, Masson's staining and transmission electron microscope analysis. Inflammatory cell infiltration was assessed by hematoxylin and eosin staining as well as immunofluorescence staining. Western blot analysis and real-time PCR were performed to assess the associated gene and protein expression, respectively. The ratio of phosphorylated/total PI3K, Akt and mTOR were also assessed by western blot analysis. Results: ① LD 50 of hypoxia was 48 â€‹h and the maximum efficacy of PRP concentration was 600 â€‹× â€‹109/L. ② ANNEXIN V-FITC/PI flow cytometry showed that the hypoxia condition significantly increased the apoptosis of cells (P â€‹< â€‹0.001) whereas PRP pretreatment significantly decreased the apoptosis of cells under hypoxia (P â€‹< â€‹0.001). The expressions of gene and protein of Bax, Bcl-2, cleaved-caspase 3 were consistent with the results of flow cytometric analysis. ③ Cell cycle analysis for flow cytometry showed the inhibitory effect of hypoxia and promotive effect of PRP pretreatment. ④ Immunofluorescence staining (HIF-1α, collagen I and III) showed the positive effect of hypoxia and negative effect of PRP on these parameters. Real-time PCR showed that type I and III collagen were 2.1 folds and 2.5 folds higher after 48 â€‹h hypoxia induction compared to the control group. PRP pretreatment significantly reduced the type I and III collagen mRNA expression of the hypoxia induced ACL fibroblasts to 78.5% and 77.7% at 48 â€‹h compared to hypoxia group (P â€‹< â€‹0.001), respectively.⑤ Cell migration assay showed that hypoxia condition significantly restrained cell migration compared with the control group. PRP could alleviate the inhibitory effect of hypoxia on fibroblasts. ⑥ Western blot analysis showed the ratio of phosphorylated/total PI3K, Akt and mTOR in hypoxia group increased to 31%, 20% and 44/% compared to control group, respectively. ⑦ The results of in vivo analysis was in accordance with the results of in vitro analysis. Conclusion: PRP can protect ACL fibroblasts via decreasing apoptosis and increasing cell viability, cell migration and cell proliferation under hypoxia condition. And such PRP protective effect was correlated with PI3K/Akt/mTOR pathway. The translational potential of this article: PRP can be used to treat patients with ACL tear by injection under arthroscopy or ultrasound guiding.

Persistent quadriceps muscle atrophy after anterior cruciate ligament reconstruction is associated with alterations in exercise-induced myokine production.

Purpose: Persistent quadriceps muscle atrophy is observed in a subset of patients following anterior cruciate ligament reconstruction (ACLR) despite the completion of comprehensive rehabilitation. Critically, quadriceps muscle atrophy correlates with muscle weakness and quadriceps strength deficits. The aim of this study was to examine the effect of resistance exercise on myokine levels and muscle atrophy status in ACLR patients with persistent quadriceps muscle atrophy. Methods: Sixteen participants between the ages of 18-39 with a Tegner score of >6 and who had undergone ACLR with hamstring graft were recruited for the study. Quadriceps muscle thicknesses were ascertained by ultrasonography and isokinetic strength assessments were made prior to commencing a single bout of resistance exercise training (RET). Blood samples were taken before and after RET and assayed for myokine expression. Self-reported activity level and knee function questionnaires were completed and recorded. Results: Clustering by quadriceps muscle size measurements created a non-atrophy group of 9 subjects and an atrophy group of 7 subjects. There were no significant between-group differences in anthropometric measurements, time post operation and knee function questionnaires, but the atrophic group comprised of patients with lower pre-injury sporting levels. The atrophy group exhibited significant lower side-to-side muscle thickness ratios and a decreasing trend in quadriceps strength deficits. Serum brain-derived neurotrophic factor (BDNF) was up-regulated in response to RET in non-atrophy group, but a negative fold change was detected in the atrophy group. Conclusion: The dysregulation in myokines plays an important role in patients failing to regain muscle mass after ACLR leading to persistent quadriceps muscle atrophy, which may potentiate greater strength deficits and poor functional recovery.

Effects of Whole-Body Vibration Therapy on Quadriceps Function in Patients With Anterior Cruciate Ligament Reconstruction: A Systematic Review.

CONTEXT: Quadriceps dysfunction is common for patients after anterior cruciate ligament reconstruction (ACLR). Whole-body vibration (WBV) could effectively treat quadriceps dysfunction. OBJECTIVE: To summarize WBV protocols for patients with ACLR and to evaluate the effects of WBV on quadriceps function. DATA SOURCES: PubMed, CINAHL, SportDiscus, Web of Science, Medline, and Embase were searched from inception to January 2020. STUDY SELECTION: Randomized controlled trials recruiting patients with ACLR, using WBV as intervention, and reporting at least 1 of the following outcomes, strength, rate of torque development (RTD), and voluntary activation ratio of quadriceps, were included. STUDY DESIGN: Systematic review. EVIDENCE LEVEL: Level 3. METHODS: This systematic review was reported according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Quality of evidence was determined by PEDro criteria and GRADE system. Participant characteristics, interventions, and the relevant results of the included studies were extracted and synthesized in a narrative way. RESULTS: In total, 8 studies were included. Of these, 2 studies had serious risk of bias. Five of 8 studies implemented a series of WBV program ranging from 2 to 10 weeks in duration, while the other 3 studies implemented a single session of WBV. Eight WBV protocols were reported. The reported outcomes consisted of quadriceps strength, RTD, and central activation ratio. WBV protocols were heterogeneous. Low quality of evidence supported that exclusive conventional rehabilitation was more effective than exclusive WBV therapy in increasing quadriceps strength. Low quality of evidence supported that WBV combined with conventional rehabilitation was more beneficial in increasing quadriceps strength when compared with conventional rehabilitation alone. Very low quality of evidence supported the efficacy of a single session of WBV on quadriceps function. CONCLUSIONS: There is no standardized WBV protocol for patients with ACLR, and the effectiveness of WBV in rehabilitation on quadriceps function remains inconclusive.