The effect of papaverine on tendon healing and adhesion in rats following Achilles tendon repair.

OBJECTIVES: The study aimed to examine the histopathological and biomechanical effects of papaverine administered intraperitoneally and locally on Achilles tendon healing in a rat model. MATERIALS AND METHODS: Forty-eight adult male Sprague-Dawley rats (range, 300 to 400 g) were used in this study conducted between October and November 2022. The rats were divided into three groups, with each group further subdivided into two for sacrifice on either the 15th (early period) or 30th (late period) day after surgery. The first (control) group received no treatment following Achilles tendon repair, while papaverine was intraperitoneally administered every other day for 10 days in the second group and locally in the third group after surgery. On the 15th and 30th days, the rats were sacrificed, and their Achilles tendons were subjected to biomechanical testing and histopathological evaluation. RESULTS: Histopathologically, there were no significant differences among the groups on the 15th day. However, on the 30th day, the locally applied papaverine group exhibited superior histopathological outcomes compared to the control group (p<0.05). Concerning the highest tensile strength values before rupture, the biomechanical assessment showed that the group receiving local papaverine treatment in the early period and both the group with systemic papaverine treatment and the one with local papaverine treatment in the late period displayed a statistically significant advantage compared to the control group (p<0.05). CONCLUSION: Locally administered papaverine has positive biomechanical effects in the early period and exhibits a positive correlation both histopathologically and biomechanically in the late period. Novel therapeutic options may be provided for patients through these findings.

The learning curve for minimally invasive Achilles repair using the "lumbar puncture needle and oval forceps" technique.

INTRODUCTION: An acute Achilles tendon rupture represents a common tendon injury, and its operative methods have been developed over the years. This study aimed to quantify the learning curve for the minimally invasive acute Achilles tendon rupture repair. METHODS: From May 2020 to June 2022, sixty-seven patient cases who received minimally invasive tendon repair were reviewed. Baseline data and operative details were collected. The cumulative summation (CUSUM) control chart was used for the learning curve analyses. Achilles tendon rupture score (ATRS), American Orthopedic Foot and Ankle Society (AOFAS) ankle/hindfoot score, and visual analog scale (VAS) at 3/6/9/12 months were calculated to assess the clinical outcomes. RESULTS: Thirty-six cases underwent at least a year of follow up and were enrolled in this study. The gender ratio and average age were 80.5% and 32.5 years. The linear equation fitted well (R2 = 0.95), and CUSUM for operative time peaked in the 12th case, which was divided into the learning phase (n = 12) and master phase (n = 24). No significant difference was detected between the two groups in clinical variables, except for the operative time (71.1 ± 13.2 min vs 45.8 ± 7.2 min, p = 0.004). Moreover, we detected one case with a suture reaction and treated it properly. CONCLUSION: Minimally invasive Achilles repair provides an opportunity for early rehabilitation. Notably, the learning curve showed that the "lumbar puncture needle and oval forceps" technique was accessible to surgeons.

In vivo study on the repair of rat Achilles tendon injury treated with non-thermal atmospheric-pressure helium microplasma jet.

Non-thermal atmospheric-pressure plasma (NTAPP) has been widely studied for clinical applications, e.g., disinfection, wound healing, cancer therapy, hemostasis, and bone regeneration. It is being revealed that the physical and chemical actions of plasma have enabled these clinical applications. Based on our previous report regarding plasma-stimulated bone regeneration, this study focused on Achilles tendon repair by NTAPP. This is the first study to reveal that exposure to NTAPP can accelerate Achilles tendon repair using a well-established Achilles tendon injury rat model. Histological evaluation using the Stoll's and histological scores showed a significant improvement at 2 and 4 weeks, with type I collagen content being substantial at the early time point of 2 weeks post-surgery. Notably, the replacement of type III collagen with type I collagen occurred more frequently in the plasma-treated groups at the early stage of repair. Tensile strength test results showed that the maximum breaking strength in the plasma-treated group at two weeks was significantly higher than that in the untreated group. Overall, our results indicate that a single event of NTAPP treatment during the surgery can contribute to an early recovery of an injured tendon.

Effect of platelet-rich plasma in Achilles tendon allograft in rabbits.

BACKGROUND: Achilles tendon is composed of dense connective tissue and is one of the largest tendons in the body. In veterinary medicine, acute ruptures are associated with impact injury or sharp trauma. Healing of the ruptured tendon is challenging because of poor blood and nerve supply as well as the residual cell population. Platelet-rich plasma (PRP) contains numerous bioactive agents and growth factors and has been utilized to promote healing in bone, soft tissue, and tendons. OBJECTIVE: The purpose of this study was to evaluate the healing effect of PRP injected into the surrounding fascia of the Achilles tendon after allograft in rabbits. METHODS: Donor rabbits (n = 8) were anesthetized and 16 lateral gastrocnemius tendons were fully transected bilaterally. Transected tendons were decellularized and stored at -80°C prior to allograft. The allograft was placed on the partially transected medial gastrocnemius tendon in the left hindlimb of 16 rabbits. The allograft PRP group (n = 8) had 0.3 mL of PRP administered in the tendon and the allograft control group (n = 8) did not receive any treatment. After 8 weeks, rabbits were euthanatized and allograft tendons were transected for macroscopic, biomechanical, and histological assessment. RESULTS: The allograft PRP group exhibited superior macroscopic assessment scores, greater tensile strength, and a histologically enhanced healing process compared to those in the allograft control group. CONCLUSIONS: Our results suggest administration of PRP on an allograft tendon has a positive effect on the healing process in a ruptured Achilles tendon.

Malvidin attenuates trauma-induced heterotopic ossification of tendon in rats by targeting Rheb for degradation via the ubiquitin-proteasome pathway.

The pathogenesis of trauma-induced heterotopic ossification (HO) in the tendon remains unclear, posing a challenging hurdle in treatment. Recognizing inflammation as the root cause of HO, anti-inflammatory agents hold promise for its management. Malvidin (MA), possessing anti-inflammatory properties, emerges as a potential agent to impede HO progression. This study aimed to investigate the effect of MA in treating trauma-induced HO and unravel its underlying mechanisms. Herein, the effectiveness of MA in preventing HO formation was assessed through local injection in a rat model. The potential mechanism underlying MA's treatment was investigated in the tendon-resident progenitor cells of tendon-derived stem cells (TDSCs), exploring its pathway in HO formation. The findings demonstrated that MA effectively hindered the osteogenic differentiation of TDSCs by inhibiting the mTORC1 signalling pathway, consequently impeding the progression of trauma-induced HO of Achilles tendon in rats. Specifically, MA facilitated the degradation of Rheb through the K48-linked ubiquitination-proteasome pathway by modulating USP4 and intercepted the interaction between Rheb and the mTORC1 complex, thus inhibiting the mTORC1 signalling pathway. Hence, MA presents itself as a promising candidate for treating trauma-induced HO in the Achilles tendon, acting by targeting Rheb for degradation through the ubiquitin-proteasome pathway.

No difference in operative time, outcomes, cosmesis, or return to activity and/or sport after minimally invasive versus open repair of primary Achilles ruptures: a retrospective review.

PURPOSE: To compare clinical outcomes and the rate of return to sport among patients that have undergone minimally invasive repair versus open approach of an acute Achilles tendon rupture. METHODS: Patients who underwent surgical repair of acute Achilles tendon rupture at a single urban academic institution from 2017 to 2020 with minimum 2-year follow-up were reviewed retrospectively. Preinjury sport participation and preinjury work activity information, the Achilles tendon Total Rupture Score (ATRS), the Tegner Activity Scale, Patient-Reported Outcomes Measurement Information System for mobility and pain interference were collected. RESULTS: In total, 144 patients were initially included in the study. Of these, 63 patients were followed with a mean follow-up of 45.3 ± 29.2 months. The mean operative time did not significantly differ between groups (p = 0.938). Patients who underwent minimally invasive repair returned to sport at a rate of 88.9% at a mean of 10.6 ± 5.8 months, compared to return rate of open procedures of 83.7% at 9.5 ± 5.5 months. There were no significant differences in ATRS (p = 0.246), Tegner (p = 0.137) or VAS pain (p = 0.317) scores between groups. There was no difference in cosmetic satisfaction between PARS and open repair groups (88.4 vs. 76.0; p = 0.244). CONCLUSION: Patients who underwent minimally invasive repair of acute Achilles tendon ruptures demonstrate no significant differences with respect to cosmesis, operative time, patient-reported outcomes and the rate and level of return to activities when compared to an open approach. LEVEL OF EVIDENCE: III.

Construct validation of a novel synthetic tendon model used for assessing surgeon performance in a simulated core suture tendon repair technique.

BACKGROUND: The strength of tendon repair is dependent on the quality of the core suture. Organic and synthetic materials have been used to simulate tendon repair for training; however, no model has undergone construct validation. OBJECTIVES: To determine the construct validity of a novel synthetic tendon repair model. METHODS: Synthetic silicone tendon models were used to simulate adult Achilles tendon (AT) and digital flexor tendon (FT). Participants were categorised into novice, intermediate, and advanced groups based on prior surgical experience. Participants repaired tendons using the modified Kessler technique. A validated motion analysis system was used to measure the duration, path length, and movement count during the simulated task. A global rating score was also used to assess the performance. RESULTS: All participants in the novice (n = 12), intermediate (n = 8) and advanced (n = 11) groups completed the tasks. The results (mean±standard deviation) were duration (872 ± 335, 492 ± 257 and 357 ± 40 s), path length (9493 ± 3173, 6668 ± 1740 and 4672 ± 1228 cm), movement count (4974 ± 673, 4228 ± 259 and 3962 ± 69) and global rating (39 ± 13, 61 ± 14, 81 ± 5), respectively. The Kruskal-Wallis test was significant for all outcome measures (p < 0.01). Significant differences in duration and movement count were identified post-hoc in the AT model for each experience group (p < 0.05), and between novice and intermediate participants for FT repair (p < 0.04). Global rating was significantly different between all groups and was highly correlated with motion metrics (p < 0.01). CONCLUSION: The results support construct validity of this novel simulated tendon repair model. The global rating scores may allow wide utility of this simulation. This model provides a valid and safe environment for surgical trainees to practice tendon repair with several cost, ethical and logistical benefits over animal tendon use. 248/250.

Roles of Plasminogen Activator Inhibitor-1 in Heterotopic Ossification Induced by Achilles Tenotomy in Thermal Injured Mice.

Heterotopic ossification (HO) is the process by which ectopic bone forms at an extraskeletal site. Inflammatory conditions induce plasminogen activator inhibitor 1 (PAI-1), an inhibitor of fibrinolysis, which regulates osteogenesis. In the present study, we investigated the roles of PAI-1 in the pathophysiology of HO induced by trauma/burn treatment using PAI-1-deficient mice. PAI-1 deficiency significantly promoted HO and increased the number of alkaline phosphatase (ALP)-positive cells in Achilles tendons after trauma/burn treatment. The mRNA levels of inflammation markers were elevated in Achilles tendons of both wild-type and PAI-1-deficient mice after trauma/burn treatment and PAI-1 mRNA levels were elevated in Achilles tendons of wild-type mice. PAI-1 deficiency significantly up-regulated the expression of Runx2, Osterix, and type 1 collagen in Achilles tendons 9 weeks after trauma/burn treatment in mice. In in vitro experiments, PAI-1 deficiency significantly increased ALP activity and mineralization in mouse osteoblasts. Moreover, PAI-1 deficiency significantly increased ALP activity and up-regulated osteocalcin expression during osteoblastic differentiation from mouse adipose-tissue-derived stem cells, but suppressed the chondrogenic differentiation of these cells. In conclusion, the present study showed that PAI-1 deficiency promoted HO in Achilles tendons after trauma/burn treatment partly by enhancing osteoblast differentiation and ALP activity in mice. Endogenous PAI-1 may play protective roles against HO after injury and inflammation.

Curcumin Improves Functional Recovery of Ruptured Tendon by Promoting Tenogenesis via PI3K/Akt Signaling.

OBJECTIVE: In our previous study, we found that local release of curcumin from nanomicelles prevents peritendinous adhesion during Achilles tendon healing. The aim of this study is to further investigate the signaling integrated by curcumin to direct the tenogenetic program of tendon stem cells contributing to tendon healing. METHODS: A surgical model of tendon rupture and repair (TRR) was established in rats. Peritendinous adhesion and inflammation, biomechanical function, and expression of ß-catenin and epithelial cellular adhesion molecule (EpCAM) were determined. A dataset was analyzed to investigate differentially expressed genes and enriched genes related to the signaling pathways. Tendon stem cells were treated with curcumin to investigate the cellular and molecular events as well as the signaling pathway. RESULTS: In rat TRR model, curcumin treatment resulted in not only significantly decreased peritendinous inflammatory but also improved tendon functional recovery along with significantly increased expressions of EpCAM and ß-catenin. Analysis of the dataset indicated that the enriched genes were positively related to differentiation pathways but negatively related to proliferation pathways. In rat tendon stem cells, curcumin treatment inhibited proliferation but promoted differentiation. Curcumin's antioxidative activity was associated with tenogenesis. The upregulated expression of tendon lineage-specific markers was dependent on phosphatidylinositol 3'-kinase/Akt (PI3K/Akt) pathway which could be a potential mechanism of tenogenesis of curcumin treatment. CONCLUSION: Curcumin could improve tendon functional recovery via promoting tenogenesis in addition to its antioxidant and anti-inflammatory activities. Curcumin induced differentiation of tendon stem/progenitor cell into tenocytes via PI3K/Akt signaling pathway. This finding provided evidence for the application of curcumin to prevent adhesion during tendon repair.

Modified Dresden Technique With a Distal Locking Suture for Achilles Tendon Repair: Technique Tip.

[Formula: see text].

Comparison of percutaneous and open repair of Achilles tendon rupture: results and complications from a single institution.

BACKGROUND: The Achilles tendon is the strongest tendon in the human body, but it is prone to injury, especially in modern times when recreational sports are growing in popularity. As a result, Achilles tendon rupture is becoming an increasingly common medical problem in modern society. The main objective of this study was to compare the outcomes of percutaneous repair and open repair for the treatment of Achilles tendon rupture. METHODS: A retrospective study was conducted involving a total of 316 patients who had undergone surgical treatment for Achilles tendon rupture between 2013 and 2021. The data collected from the medical history of these patients included the type of surgical procedure, the mechanism of injury, the age and sex of the patients, the time spent in the hospital, and any possible complications of the surgical treatment (such as infections, reruptures, or sural nerve injuries). RESULTS: The study revealed that there was no significant difference between percutaneous and open surgical approaches in terms of sural nerve injury. However, there was a statistically significant advantage of the percutaneous method in terms of the number of infections, which was significantly lower than that of the open method. Additionally, the median length of hospital stay was found to be four days longer with the open approach. However, the study noted that a statistically significant advantage of the percutaneous method for rerupture could not be established due to the small number of patients with rerupture and the insufficient ratio of patients with rerupture in relation to the size of the observed population. CONCLUSIONS: Percutaneous repair is an effective treatment option for Achilles tendon rupture and has outcomes equal to or better than those of open repair. Therefore, this approach is recommended as the preferred method of treatment due to the presence of fewer complications, provided that the indications for this technique are appropriate.

Endoscopic peroneus brevis tendon transfer for chronic ruptures of the Achilles tendon: surgical technique.

Chronic Achilles tendon rupture is usually defined as a rupture diagnosed 4-6 weeks after injury. The management of chronic Achilles tendon rupture (CATR) is a topic of hot debate, and no consensus has been achieved. Surgical management of CATR is recommended. Several approaches, techniques, and grafts have been described. Open techniques carry a high risk of wound breakdown, infection, and necessitate long rehabilitation times. Surgical techniques with smaller incisions to reduce the risk of scar fibrosis, pain, and infection are becoming common. The ipsilateral tendon of the hallux flexor longus and the peroneus brevis is commonly used. Endoscopic transfer of the peroneus brevis tendon is an innovative alternative to other procedures, with comparable results of other autografts even in elite athletes. The tendon of the peroneus brevis is harvested by tendoscopy before performing a calcaneal tendon endoscopy and fixing the graft in a calcaneal tunnel using an interference screw. After surgery, an anterior splint is placed for 3 weeks with immediate forefoot weight bearing. The rehabilitation starts on the 15th postoperative day.

Higher risk of Achilles tendon ruptures at competition than training sites in female collegiate gymnasts.

BACKGROUND: Reportedly, 17.2% of collegiate female gymnasts experience Achilles tendon ruptures (ATRs). Cumulative microtraumas resulting in chronic tendinopathy/tendinitis may contribute to this high injury risk. We hypothesized that the risk of ATRs in female collegiate gymnasts increases with years of competitive gymnastics, that non-steroidal anti-inflammatory drug (NSAID) use is associated with less ATRs, and that the risk is larger during competition than training. METHODS: Female gymnasts from 78 USA collegiate teams completed a survey assessing the prevalence of ATRs, NSAID use, age at which competitive gymnastics started and age at which ATR occurred, and whether ATRs occurred during training or competition. RESULTS: Twenty-one of 103 gymnasts (20.4%, 95% CI: 13.6% to 29.4%) experienced ATRs. Eighteen of 21 ruptures (85.7%, 95% CI: 61.3% to 95.8%) occurred after more than ten years of competitive gymnastics (mean: 14.0±2.6 years, 95% CI: 12.8 to 15.2 years). ATRs occurred 0.08±0.01 (95% CI: 0.06 to 0.11) times per 1000 hours at training versus 1.85±0.11 (95% CI: 1.60 to 2.10) times per 1000 hours at competition (P<0.05). Prevalence of NSAID use was 27.6% (95% CI: 18.6% to 39.0%) in gymnasts without ATR but only 5.5% (95% CI: 0.6% to 35.5%, P=0.09) in gymnasts with ATR. Multiple regression analysis demonstrated a negative association between NSAID use and incidence of ATRs (P<0.05). CONCLUSIONS: Female collegiate gymnasts are at high risk for ATRs, especially after more than ten years of competitive gymnastics and during competition.

ALT in combination with triple-rolled TFL for reconstruction of a complex tendoachilles defect: technical details and rehabilitation regime.

A fit man in his 60s presented with an infected Achilles tendon (AT) following two failed repairs for a traumatic rupture. Initial debridement of necrotic tissue resulted in a large soft tissue defect requiring robust coverage. Following aggressive wound management, an anterolateral thigh flap was elevated with tensor fasciae latae (TFL) which was triple-rolled to provide soft tissue coverage and tendon reconstruction.The flap remained healthy and was monitored with a flow coupler device. Initially, the foot was placed in plantarflexion before gradually increasing the angle to neutral and a thermoplastic splint was used to offload pressure on the flap. Following 1 month of non-weight-bearing, gentle mobilisation began. Three months postoperatively, the patient could walk, had resumed indoor cycling and demonstrated a comparable heel raise with the contralateral side. MRI showed a taut TFL attached to the distal AT and ultrasound showed a smoothly gliding TFL.

Return to Play and Functional Outcomes Following Treatment of Acute Achilles Tendon Ruptures: A Systematic Review and Meta-Analysis.

Return to play (RTP) and functional outcomes are critical to treatment success for acute Achilles tendon rupture (AATR). This systematic review and meta-analysis explored treatment superiority essential in optimal treatment selection concerning individual patients and their expectations regarding RTP and functional outcomes. This study was in accordance with the preferred reporting items for systematic reviews and meta-analyses guidelines. The included studies were assessed regarding the level and quality of evidence. Fixed-effects models were employed for I2 < 25% and random-effects models for I2 ≥ 25%. The RTP rate meta-analysis of surgical vs conservative treatment revealed no significant difference. This was similar to the subgroup analysis of open repair and conservative treatment. The RTP rate and Achilles Tendon Total Rupture Score (ATRS) meta-analysis of open repair + earlier rehabilitation (ER) vs + later rehabilitation (LR) also revealed no significant differences. The mean time to RTP meta-analysis of open repair + ER vs + LR showed that open repair + ER was significantly favored (-4.19 weeks; p = .002). The ATRS meta-analysis of conservative treatment with ER vs with LR revealed no significant difference. This meta-analysis has revealed that the RTP rates following treatment of AATR are high. Therefore, the decision for surgical vs conservative treatment or open repair + ER vs + LR for AATR should not be selected based on the expectation of RTP. However, open repair + ER can be advocated over + LR for reduced mean time to RTP.

Applications of medical imaging in the monitoring and rehabilitation of physical conditions in athletes

By means of imaging, athletic injuries can be more comprehensively and accurately screened and functionally evaluated, so as to guide the treatment and rehabilitation after athletic injuries in a more targeted manner. Chronic injuries and tendinopathies of the Achilles tendon occur mostly in the middle and lower part of the Achilles tendon, which is the most frequent site of Achilles tendon rupture, and Achilles tendon rupture will lead to a huge impact on athletic injurie performance, and even end their athletic career prematurely. Ultrasound imaging technology can clearly and completely show the tissue and its continuity changes, which is helpful for the setting of rehabilitation program and the judgment of prognosis. The Siemens VTIQ provides quantitative information on the viscoelastic properties of the tissue, allowing an accurate and safe assessment of the elastic properties of the Achilles tendon. In this paper, the third generation ARFI technique, VTIQ technology, was applied to study the Achilles tendon of healthy youth and professional athletes to obtain the effects of exercise on the Achilles tendon and to provide medical imaging support for monitoring the health of the Achilles tendon in athletes and for the post-injury rehabilitation process (AU)

Epidemiology of insertional and midportion Achilles tendinopathy in runners: A prospective cohort study.

BACKGROUND: Achilles tendinopathy (AT) is a common problem among runners. There is only limited evidence for risk factors for AT, and most studies have not defined the AT subcategories. No study has compared the incidence and risk factors between insertional AT and midportion AT, though they are considered distinct. This study aimed to assess incidence and risk factors of AT based on data from a large prospective cohort. The secondary aim was to explore differences in risk factors between insertional and midportion AT. METHODS: Participants were recruited from among registered runners at registration for running events. Questionnaires were completed at baseline, 1 month before the event, 1 week before the event, and 1 month after the event. Information concerning demographics, training load, registered events, and running-related injuries were collected at baseline. The follow-up questionnaires collected information about new injuries. A pain map was used to diagnose midportion and insertional AT. The primary outcome was the incidence of AT. Multivariable logistic regression analysis was applied to identify risk factors for the onset. RESULTS: We included 3379 participants with a mean follow-up of 20.4 weeks. The incidence of AT was 4.2%. The proportion of insertional AT was 27.7% and of midportion AT was 63.8%; the remaining proportion was a combined type of insertional and midportion AT. Men had a significantly higher incidence (5%, 95% confidence interval (95%CI): 4.1%-6.0%) than women (2.8%, 95%CI: 2.0%-3.8%). AT in the past 12 months was the most predominant risk factor for new-onset AT (odds ratio (OR) = 6.47, 95%CI: 4.27 -9.81). This was similar for both subcategories of AT (insertional: OR = 5.45, 95%CI: 2.51-11.81; midportion: OR = 6.96, 95%CI: 4.24-11.40). Participants registering for an event with a distance of 10/10.55 km were less likely to develop a new-onset AT (OR = 0.59, 95%CI: 0.36-0.97) or midportion AT (OR = 0.47, 95%CI: 0.23 -0.93). Higher age had a significant negative association with insertional AT (OR = 0.97, 95%CI: 0.94-1.00). CONCLUSION: The incidence of new-onset AT among recreational runners was 4.2%. The proportion of insertional and midportion AT was 27.7% and 63.8%, respectively. AT in the past 12 months was the predominant risk factor for the onset of AT. Risk factors varied between insertional and midportion AT, but we could not identify clinically relevant differences between the 2 subtypes.

Focused ultrasound as an alternative to dry needling for the treatment of tendinopathies: A murine model.

Tendinopathies account for 30% of 102 million annual musculoskeletal injuries occurring annually in the United States. Current treatments, like dry needling, induce microdamage to promote healing but produce mixed success rates. Previously, we showed focused ultrasound can noninvasively create microdamage while preserving mechanical properties in ex vivo murine tendons. This present study compared growth factor, histological, and mechanical effects after focused ultrasound or dry needling treatments in an in vivo murine tendon injury model. Partial Achilles tenotomy was performed in 26 rats. One-week postsurgery, tendons were treated with focused ultrasound (1.5 MHz, 1-ms pulses at 10 Hz for 106 s, p+ = 49 MPa, p- = 19 MPa) or dry needling (30 G needle, 5 fenestrations over 20 s) and survived for 1 additional week. Blood was collected immediately before and after treatment and before euthanasia; plasma was assayed for growth factors. Treated tendons and contralateral controls were harvested for histology or mechanical testing. No differences were found between treatments in release of insulin growth factor 1 and transforming growth factor beta; vascular endothelial growth factor A concentrations were too low for detection. Histologically, focused ultrasound and dry needling tendons displayed localized fibroblast infiltration without collagen proliferation with no detectable differences between treatments. Mechanically, stiffness and percent relaxation of dry needling tendons were lower than controls (p = 0.0041, p = 0.0441, respectively), whereas stiffness and percent relaxation of focused ultrasound tendons were not different from controls. These results suggest focused ultrasound should be studied further to determine how this modality can be leveraged as a therapy for tendinopathies.

Preinjury Knee and Ankle Mechanics during Running Are Reduced among Collegiate Runners Who Develop Achilles Tendinopathy.

INTRODUCTION: Achilles tendinopathies (AT) are common in runners, but prospective data assessing running mechanics associated with developing AT are limited. Asymmetry in running mechanics is also considered a risk factor for injury, although it is unknown if the problematic mechanics occur on the injured limb only or are present bilaterally. PURPOSE: This study aimed to prospectively identify differences in preinjury running biomechanics in collegiate runners who did and did not develop AT and determine if between-limb asymmetries were associated with which limb developed AT. METHODS: Running gait data were obtained preseason on healthy collegiate cross-country runners, and AT incidence was prospectively recorded each year. Spatiotemporal, ground reaction forces, and joint kinematics and kinetics were analyzed. Linear mixed-effects models assessed differences in biomechanics between those who did and did not develop AT during the subsequent year. Generalized linear mixed-effects models determined if the asymmetry direction was associated with which limb developed an AT, with odds ratios (OR) and 95% confidence intervals (95% CI) reported. RESULTS: Data from 106 runners were analyzed and 15 developed AT. Preinjury biomechanics of runners who developed AT showed less peak knee flexion (noninjured: 45.9° (45.2°-46.6°), injured: 43.2° (41.5°-44.9°), P < 0.001), ankle dorsiflexion (noninjured: 28.7° (28.0°-30.2°), injured: 26.0° (23.8°-28.3°), P = 0.01), and knee extensor moment (noninjured: -2.18 (N·m)·kg -1 (-2.24 to -2.12 (N·m)·kg -1 ), injured: -2.00 (N·m)·kg -1 (-2.17 to -1.84 (N·m)·kg -1 ), P = 0.02). The limb demonstrating less peak knee flexion had greater odds of sustaining an AT (OR, 1.29 (1.00-1.65), P = 0.05). CONCLUSIONS: Knee and ankle kinematics, in addition to knee kinetics, were associated with developing an AT. Monitoring these mechanics may be useful for prospectively identifying runners at risk of developing AT.

Musculotendinous ruptures of the achilles tendon had greater heel-rise height index compared with mid-substance rupture with non-operative management: A retrospective cohort study.

INTRODUCTION: Achilles tendon ruptures (ATRs) may occur at varying locations with ruptures at the mid-substance (MS) of the tendon most common, followed tears at the musculotendinous (MT) junction. There is scant literature about the outcome of MT ATR. This study compared the outcome of patients with a MT ATR with patients following a MS ATR. METHODS: The diagnostic features and clinical outcome of 37 patients with a MT ATR were compared with a cohort of 19 patients with a MS ATR. Patients in both groups were managed non-operatively and received the same rehabilitation protocol with weight-bearing rehabilitation in protective functional brace. RESULTS: From February 2009 to August 2023, 556 patients presented with an ATR. Of these, 37 (6.7 â€‹%) patients were diagnosed with a MT tear. At final follow-up, at 12 months following injury, the MT group reported an Achilles tendon total rupture score (ATRS) of mean (standard deviation (SD)) of 83.6 (3.5) (95 â€‹% confidence interval (CI) 81.8, 85.4) and median (inter-quartile range (IQR)) ATRS of 86 points (78-95.5) and the MS group mean (SD) of 80.3 (8.5) (95%CI) 76.1, 80.5) and median (IQR) of 87 points (59-95) (p â€‹= â€‹0.673). Functional evaluation, however, revealed statistically significant differences in mean (SD) heel-rise height index MT group 79 â€‹% (25) (95%CI 65.9, 92.1) and MS group 59 â€‹% (13) (95%CI 51.9, 67.1) (p â€‹= â€‹0.019). In the MT rupture group, there were considerably less complications than the MS rupture group. CONCLUSIONS: When managed non-operatively, with only a 6 weeks period of brace protection, patients have little limitation although have some residual reduction of single heel-rise at the one-year following MT ATR. LEVEL OF EVIDENCE: IV.