Tendon Blood Flow Research Articles

Comprehensive assessment of heavy slow resistance training and high-dose therapeutic ultrasound in managing patellar tendinopathy, a randomized single-blind controlled trial

BackgroundPatellar tendinopathy (PT) is a common sport injury prone to recurrence. Heavy Slow Resistance Training (HSR) and High-Dose Therapeutic Ultrasound (TUS) are frequently used interventions for PT. However, the combined effectiveness of these therapies remains unclear. This study investigated the impact of combination therapy on functional outcomes in patients with PT.MethodsFifty-one college students aged 18–25, diagnosed with PT via musculoskeletal ultrasound, were randomly assigned to one of three groups (n = 17 per group): combined HSR and high-dose TUS, HSR training alone, or high-dose TUS alone. The eight-week intervention included assessments using the Victorian Institute of Sport Assessment-Patella (VISA-P), Visual Analogue Scale (VAS), Y-balance Test (YBT), Modified Thomas Test (MTT), Horizontal Jumping Distance, Maximum Isometric Muscle Strength Test, and musculoskeletal ultrasound for patellar tendon thickness and blood flow. Assessments were conducted at baseline and post-intervention, with a follow-up VISA-P assessment at week 16. This randomized, single-blind controlled trial was registered on ISRCTN11447397 (www.ISRCTN.com) on February 17, 2024 (retrospectively registered).ResultsAll groups demonstrated significant improvements in VISA-P scores at the end of the intervention compared to baseline (p < 0.01), with the combined group showing the greatest improvement (21 points). Follow-up at week 16 revealed continued improvement in VISA-P scores for the combined and HSR groups, while the TUS group showed a slight decrease (from 74 to 70). All groups displayed significantly reduced VAS scores post-intervention (p < 0.01) compared to baseline, indicating decreased pain. While no significant between-group differences were observed in pre-intervention VAS scores, post-intervention results revealed significant differences between the combined and HSR groups (p < 0.05), as well as between the combined and TUS groups (p < 0.01).ConclusionBoth exercise intervention and high-dose TUS appear effective in reducing pain and improving motor function in individuals with PT. However, the therapeutic effect of high-dose TUS alone seems limited compared to exercise intervention. The combined application of both methods yielded the most significant improvements in pain relief and motor function enhancement.

Application of indocyanine green fluorescence angiography in evaluating blood flow in rotator cuff tears: a preliminary study

BackgroundThe relationship between the degree of vascularization at the edge of a torn rotator cuff tendon and cuff healing remains unclear. The purpose of this study was to employ indocyanine green (ICG) fluorescence angiography to evaluate the blood flow at the edge of a torn rotator cuff tendon under the subacromial view. MethodsThirteen shoulders of 13 patients who underwent arthroscopic repair of full-thickness rotator cuff tears were included in this prospective study. Viewing from the posterolateral portal, ICG at 0.2 mg/kg body weight was intravenously administered, and the blood flow was recorded. After resecting the poorly vascularized torn edge of the tendon, ICG administration was repeated at the same volume. The fluorescence intensity and perfusion time of the tendon blood flow were evaluated using video analysis and modeling tools. Cuff integrity was evaluated using magnetic resonance imaging at 6 months postoperatively. Patients were divided into healed and retear groups, and the differences in the degree of blood flow were evaluated. ResultsICG fluorescence angiography could visualize the blood flow in the rotator cuff tendon, and the torn edge of the tendon with poor blood flow was resected. The overall retear rate was 23.1 % (3/13). Based on quantitative analysis, the fluorescence intensity factors were significantly lower in the retear group than in the healed group before tendon débridement. The retear rate in the high blood flow group was 0% (0/7), while that in the low blood flow group was 50.0% (3/6). ConclusionsICG fluorescence angiography may play a role in the future of shoulder arthroscopy. Further study is needed to determine the effect of blood flow on tendon healing.

The twisted Achilles tendon microvasculature.

The Achilles tendon (AT) is reportedly the most vulnerable to rupture at the midportion, a section of relative hypovascularity. It has been postulated that the twisted structure of this tendon may constitute a critical factor contributing to increased propensity to vascular compromise, decreased regenerative capacity, and rupture in the midsection of the AT. In this review, we will give an overview of the most relevant research on AT vasculature and twist, and delve into the interplay between the two elements in the context of AT disorders. The pertinent body of research suggests a considerable variability in tendon twist among individuals, which likely constitutes a determining factor in the extent to which vessels coursing along and between AT fibers are compressed during contraction-induced elongation of the tendon. Consequently, further research is necessary to investigate the precise association between tendon torsion and blood flow within the AT.

Complete Closed Rupture of the Medial Bundle of the Flexor Hallucis Brevis Tendon Off the Medial Sesamoid Insertion

Category: Midfoot/Forefoot; Basic Sciences/Biologics; Sports; Trauma Introduction/Purpose: Flexor tendon injuries of the hallux are uncommon overall but when they happen, the flexor hallucis longus (FHL) tendon is the most frequent one affected. The rupture of FHL usually results from open injuries and deep cuts in the sole at the base of the toe;4 complete subcutaneous ruptures are extremely rare.5 There are around 36 cases reported of complete or partial closed ruptures of the FHL tendon along its entire course6 and the majority of the partial ruptures correspond to dancers and athletes.7 As far as FHB, we found a few reports of calcific tendinitis of the medial bundle and cases of calcifying tendinitis.8 To the best of our knowledge, this is the only case report of isolated closed rupture of the FHB tendon. Methods: A 33-year-old man, amateur soccer player, presented with mild swelling, ecchymosis, and increasing pain in the left hallux triggered by movement and palpation, relieved by rest. He sustained a direct axial blow and blunt force trauma with a soccer ball plus hyperextension. Standard bilateral weightbearing feet radiographs were normal. Physical exam revealed the left hallux normally aligned but with limited painful motion of 20° each way and no obvious instability. Palpation of the left first metatarsophalangeal joint was tender but not particularly over the sesamoids. MRI revealed an avulsion of the flexor Hallucis Brevis tendon off the proximal aspect of the medial sesamoid accompanied by fluid and edema, effusion in the first MTP joint and bone contusions in the first metatarsal head and dorsal base of the first proximal phalanx. Treatment with a toe spacer and postop sandal with the toe straight with an extension block was decided. Results: Tendon's blood flow around the sesamoids is limited making it susceptible to degenerative rupture. The most common mechanism of complete tendon rupture is direct open injury. Closed rupture is very rare and complete rupture in closed injury is even more. We did not find reports on third degree type of injuries, neither for any kind of isolated rupture of FHB. In our patient's case, dorsiflexion stretched all plantar soft tissue around the first MTP but he was able to do active movement of the great toe probably due to the FHL and lateral FHB insertion integrity. We found few reports of second-degree strain injury of FHL and FHB in a chronic setting, all treated conservatively with partial immobilization and strapping of the hallux to prevent extension. After conservative treatment at 3 months follow-up, our patient presented with no subjective complains, normal motion, stability and alignment of the hallux. Conclusion: Despite an extensive literature search, we did not find a similar injury, and this is probably the first time it is described. As found in our research, the most common injury related to the flexor tendons of the hallux are in soccer players and involve the FHL or both.23 These findings made us conclude that these injuries are either under-diagnosed or exceptional.

Effects of isometric loading intensity on patellar tendon microvascular response.

Acute increases in tendon blood flow and oxygenation after stress (i.e., hyperemic response) can enhance tendon recovery. While loading intensity is a fundamental part of resistance training programs, its effects on tendon's hyperemic response are unknown. This study aimed to compare acute changes in total (total hemoglobin [THb]) and oxygenated hemoglobin (HbO2 ) concentrations in the patellar tendon after isometric exercise at different intensities. Thirteen participants performed 8 (5s) isometric knee extensions at 25%, 50%, and 75% maximal load (maximal voluntarily isometric contraction [MVIC]), separated by 20 min recovery, prescribed in randomized and counterbalanced order. Changes in patellar tendon THb, HbO2 and deoxygenated hemoglobin (HHb) in response to exercise at each intensity were measured using near-infrared spectroscopy. Post-exercise, HbO2 increased with 50% ( = 0.305, f= 5.26, p< 0.01) and 75% ( = 0.245, f= 4.56, p< 0.01) but not 25% ( = 0.088, f= 1.16, p= 0.339) MVIC, while THb increased in 50% ( = 0.305, f= 5.26, p= 0.01) but not 25% ( = 0.067, f= 0.865, p= 0.51) or 75% ( = 0.126, f= 1.729, p= 0.14) MVIC. Additionally, increasing load from 25% to 50% MVIC resulted in greater THb (f= 2.459, p= 0.43), HbO2 (f= 3.389, p= 0.13) and HHb (f= 0.320, p= 0.01) post-exercise responses, but no differences were observed between 50% and 75% MVIC (THb: f= 0.748, p= 0.59; HbO2 : f= 0.825, p= 0.54; HHb: f= 0.713, p= 0.62). Our results suggest there is a loading threshold at ~50% MVIC at which the tendon hyperemic response is fully achieved. Training above this intensity is not expected to provide any additional change to the tendon microvascular response. Therefore, moderate loading seems to be sufficient to fully elicit the patellar tendon hyperemic response that's believedto stimulate tendon healing.

Tendon blood flow, angiogenesis, and tendinopathy pathogenesis

Physical exercise results in a duration and intensity-dependent vascular response in healthy human tendon. In overused (tendinopathy) and damaged tendon, angiogenic pathways are activated and neovascularization is observed. Whereas no direct relationship exists between the amount of neovessels and degree of tendinopathy symptoms, almost all tendinopathic patients have elevated neovascularization and tendon blood flow, as assessed by Doppler ultrasound methodology. The enhanced flow in tendinopathy can be successfully abolished by heavy resistance training. Already in the early time-phase of tendinopathy (<3 months), neovascularization in the tendon exists but the causal sequence of vascular, metabolic, nociceptive, and matrix tissue changes in tendon pathology is not fully understood. Nevertheless, existing evidences point at neovascularization being an important component of pathogenesis and may occur already before the development of clinical symptoms in tendinopathy.

Pain Relief after Extracorporeal Shock Wave Therapy for Patellar Tendinopathy: An Ultrasound Evaluation of Morphology and Blood Flow

We aimed to investigate the changes caused by focused extracorporeal shock wave pain therapy (f-ESWT) in patients with patellar tendinopathy by means of ultrasound imaging. We included 18 knees from 11 college athletes with patellar tendinopathy. We assessed the tendon thickness and blood flow of the patellar tendon using ultrasound imaging, rest pain using NRS and tenderness using a pressure pain gauge. We recorded four measurements: immediately before f-ESWT (PRE①) and after f-ESWT (POST①) and two weeks after the first irradiation before f-ESWT (PRE②) and after f-ESWT (POST②). Only the resting pain in both the first and second irradiations showed a significant difference immediately before and after the treatment. In terms of pain changes after two weeks later, we observed significant differences in the resting pain between PRE① and PRE② and also in the resting pain, tenderness and blood flow area between PRE① and POST②. No significant difference was seen in the tendon thickness. We concluded that pain in the patellar tendon at rest decreased before and after irradiation, suggesting that f-ESWT may have influenced the nociceptive structures and had an analgesic effect.

Acute Effects of Warming Up on Achilles Tendon Blood Flow and Stiffness.

Pieters, D, Wezenbeek, E, De Ridder, R, Witvrouw, E, and Willems, T. Acute effects of warming up on Achilles tendon blood flow and stiffness. J Strength Cond Res 36(10): 2717-2724, 2022-The aim of this study was to investigate the acute effect of frequently used warm-up exercises on the Achilles tendon blood flow and stiffness. In doing so, we want to explore which exercises are suitable to properly prepare the athlete's Achilles tendon in withstanding high amounts of loading during sport activities. This knowledge could help sport physicians and physiotherapists when recommending warm-up exercises that are able to improve sport performance while reducing the injury susceptibility. Achilles tendon blood flow and stiffness measurements of 40 healthy subjects (20 men and 20 women) aged between 18 and 25 years were obtained before and immediately after 4 different warm-up exercises: running, plyometrics, eccentric heel drops, and static stretching. The effect of these warm-up exercises and possible covariates (sex, age, body mass index, rate of perceived exertion, and sports participation) on the Achilles tendon blood flow and stiffness was investigated with linear mixed models. The level of significance was set at α = 0.05. The results of this study showed a significant increase in Achilles tendon blood flow and stiffness after 10 minutes of running ( p < 0.001 and p < 0.001) and plyometrics ( p < 0.001 and p = 0.039). Static stretching and eccentric exercises elicited no significant changes. From these results, it could be suggested that warm-up exercises should be intensive enough to properly prepare the Achilles tendon for subsequent sport activities. When looking at Achilles tendon blood flow and stiffness, we advise the incorporation of highly intensive exercises such as running and plyometrics within warm-up programs.

Does application of abduction brace after arthroscopic rotator cuff repair improve blood flow around posterosuperior rotator cuff and repair site, affecting pain levels and clinical and structural outcomes? A pilot randomized controlled trial

BackgroundAs per some cadaveric studies, blood flow in posterosuperior rotator cuff tendons improves in the abducted shoulder position compared with the neutral position. In a clinical post–rotator cuff repair scenario, the impact of abduction on altered blood flow in and around the posterosuperior rotator cuff tendons is unknown in terms of clinical outcomes and structural healing.Materials and methodsThis study included 42 eligible patients aged between 40 and 70 years with clinically diagnosed and radiologically confirmed rotator cuff tears undergoing arthroscopic rotator cuff repair. Patients were randomly allocated to undergo application of either an abduction brace (group 1) or an arm pouch (group 2). On postoperative day 1, power Doppler scanning was performed on the index shoulder in adduction and 30° of abduction in each patient; the allocated treatment (abduction brace or arm pouch) was then applied. Power Doppler scanning was repeated at 6 weeks in the immobilization position assigned to the patient (abduction or adduction). The vascular flow in 6 regions was noted as per the criteria of Fealy et al. A visual analog scale score was assessed preoperatively and at 1, 3, 6, 12, and 56 weeks postoperatively. Clinical assessment was performed with the Constant-Murley score at 1 year, and structural healing of the cuff was assessed using ultrasonography at 3 and 12 months.ResultOn the first postoperative day, blood flow was significantly higher in all 6 areas of the shoulder in group 1 than in group 2. The mean total vascular score was significantly higher in group 1 than in group 2 on postoperative day 1 (P = .0001) and remained so at 6 weeks (P = .0001). However, significantly higher vascular flow was noted only in the peribursal region at 6 weeks in group 1 (P = .04). No significant difference in the visual analog scale score was noted between the 2 groups at any given point of follow-up. Furthermore, no clinical and structural healing differences were noted between the 2 groups at final follow-up.ConclusionHigher blood flow in and around the posterosuperior rotator cuff owing to an abducted shoulder position with an abduction brace in the first 6 weeks postoperatively fails to offer any advantage in terms of lower pain levels, better clinical scores, or superior cuff healing.

High Intensity Shoulder Exercise Improves Function, Pain And Tendinous Blood Flow In Subacromial Pain Syndrome.

Subacromial pain syndrome (SAPS) defined as pain of non-traumatic origin localized around the acromion, is a debilitating, common and often chronic condition. Among many proposed underlying causes of SAPS, hypoperfusion and hypoxic conditions in and around the tendons may be an intrinsic cause of SAPS. Exercise therapy with low load is the advocated treatment of choice for SAPS. PURPOUSE: To determine if high intensity aerobic interval training (HIIT) of the rotator cuff was feasible, more effective in improving endurance and reducing pain compared to low intensity exercises. Additionally, to examine the response of tendinous microcirculation following the exercise therapy. METHODS: 21 subjects with chronic SAPS randomized to two groups: HIIT (n=13) and control group (CG) (n=8) was tested before and after 8 weeks of exercise therapy. Endurance performance was assessed by an incremental abduction adduction exercise of the arm to exhaustion (TTE). Contrast enhanced ultrasound (CEUS) of the m. supraspinatus and tendon was utilized to indicate tendon blood flow. Limitations in daily life was assessed by the shoulder pain and disability index (SPADI). RESULTS: Endurance in the TTE-test improved by an estimated 233 seconds more on average in HIIT than in CG (p=0.001, 95%CI: 102 to 363), the change was significant in HIIT (p<0.001), no change was seen in CG. The SPADI score was reduced 22 points more on average in HIIT (p=0.017, 95%CI: -40 to -5). The change from pre to post-test was significant in HIIT(p<0.001), but not in the CG. HIIT also experienced less pain during exercise after the intervention compared to CG (p<0.001). CEUS indicated an increase in tendinous blood flow in the HIIT group (p=0.019), no change was observed in CG. CONCLUSIONS: HIIT rotator cuff exercise appear to be a feasible intervention in SAPS, reducing pain and increasing endurance performance more than exercise with low load. CEUS indicate that HIIT may increase tendon microcirculation, thus abating a potential hypoperfused/ hypoxic state underlying the condition.

High-Intensity Shoulder Abduction Exercise in Subacromial Pain Syndrome.

This study aimed to determine if adding high-intensity aerobic interval training (HIIT) of the rotator cuff to usual care was feasible in SAPS and improved shoulder endurance more than usual care alone, as well as to examine the influence on shoulder pain and disability and the response of tendinous microcirculation after HIIT. Twenty-one subjects with chronic SAPS were randomized to two groups: experimental group (EG; n = 13) receiving HIIT in addition to treatment as usual and control group (CG; n = 8) receiving treatment as usual. Before and after 8 wk of exercise therapy, endurance performance was assessed by an incremental abduction exercise of the arm to exhaustion (TTE). Pain and disability was assessed by the shoulder pain and disability index (SPADI). Contrast-enhanced ultrasound of the musculus supraspinatus and tendon was utilized to indicate tendon blood flow. Endurance in the TTE test improved by an estimated 233 s more on average in EG than in CG (P = 0.001; 95% confidence interval, 102 to 363). The SPADI score was reduced 22 points more on average in EG (P = 0.017; 95% confidence interval, -40 to -5). The change from pretest to posttest was significant in EG for both TTE test and SPADI improvement (P < 0.001). EG also experienced less pain during exercise after the intervention compared with CG (P < 0.001). Contrast-enhanced ultrasound indicated an increase in tendinous blood flow in EG (P = 0.019). HIIT rotator cuff exercise seems to be a feasible intervention in SAPS, increasing endurance performance more than usual care alone.

Is sleep position associated with glenohumeral shoulder pain and rotator cuff tendinopathy: a cross-sectional study

BackgroundGlenohumeral pain and rotator cuff tendinopathy (RCT) are common musculoskeletal complaints with high prevalence among working populations. The primary proposed pathophysiologic mechanisms are sub-acromial RC tendon impingement and reduced tendon blood flow. Some sleep postures may increase subacromial pressure, potentially contributing to these postulated mechanisms. This study uses a large population of workers to investigate whether there is an association between preferred sleeping position and prevalence of: (1) shoulder pain, and (2) rotator cuff tendinopathy.MethodsA cross-sectional analysis was performed on baseline data from a multicenter prospective cohort study. Participants were 761 workers who were evaluated by questionnaire using a body diagram to determine the presence of glenohumeral pain within 30 days prior to enrollment. The questionnaire also assessed primary and secondary preferred sleep position(s) using 6 labeled diagrams. All workers underwent a structured physical examination to determine whether RCT was present. For this study, the case definition of RCT was glenohumeral pain plus at least one of a positive supraspinatus test, painful arc and/or Neer’s test. Prevalence of glenohumeral pain and RCT were individually calculated for the primary and secondary sleep postures and odds ratios were calculated.ResultsAge, sex, Framingham cardiovascular risk score and BMI had significant associations with glenohumeral pain. For rotator cuff tendinopathy, increasing age, Framingham risk score and Hand Activity Level (HAL) showed significant associations. The sleep position anticipated to have the highest risk of glenohumeral pain and RCT was paradoxically associated with a decreased prevalence of glenohumeral pain and also trended toward being protective for RCT. Multivariable logistic regression showed no further significant associations.ConclusionThis cross-sectional study unexpectedly found a reduced association between one sleep posture and glenohumeral pain. This cross-sectional study may be potentially confounded, by participants who are prone to glenohumeral pain and RCT may have learned to avoid sleeping in the predisposing position. Longitudinal studies are needed to further evaluate a possible association between glenohumeral pain or RCT and sleep posture as a potential risk factor.

Activity-Induced Increase in Achilles Tendon Blood Flow Is Age and Sex Dependent

Background: Previous research of a young adult population identified a lower increase in Achilles tendon blood flow immediately after a running activity as a significant predictor for the development of Achilles tendinopathy (AT). Furthermore, advancing age is often mentioned as a risk factor for the development of AT, and the highest incidence for AT is reported to occur in middle-aged recreational male athletes. Purpose: To investigate the effect of age, sex, and type of physical activity on the increase in Achilles tendon blood flow. Study Design: Controlled laboratory study. Methods: Blood flow measurements of 33 subjects aged 18 to 25 years and 30 subjects aged 40 to 55 years were obtained before and after 4 physical activities performed in randomized order: running, cycling, dynamic stretching, and rope skipping. Blood flow measurements of the Achilles tendon were performed before, immediately after, 5 minutes after, and 10 minutes after the physical activities. The effect of age, sex, and physical activities on the increase in blood flow was investigated with linear mixed models. Results: The results of this study identified that running, rope skipping, and cycling resulted in a significant increase in tendon blood flow (P ≤ .001), whereas stretching did not. Prominent was the finding that the increase in blood flow after activity was significantly lower in the older population as compared with the younger population (P < .001). Furthermore, male participants in the older group showed a significantly lower increase in tendon blood flow than did their female counterparts (P = .019). Conclusion: This study identified that sex and age significantly influence the increase in blood flow after activity, possibly explaining the increased risk for AT among middle-aged recreational athletes. Clinical Relevance: This study possibly identified one of the mechanisms explaining why an older male population is at increased risk for developing AT. Given that the lower increase in blood flow is an identified risk factor according to previous research, preventative measures should focus on improving this blood flow during physical activity in the physically active older male population. Registration: NCT03218605 (ClinicalTrials.gov identifier).

Intravoxel incoherent motion (IVIM) imaging in human achilles tendon.

Limited microcirculation has been implicated in Achilles tendinopathy and may affect healing and disease progression. Existing invasive and noninvasive approaches to evaluate tendon microcirculation lack sensitivity and spatial coverage. To develop a novel Achilles tendon intravoxel incoherent motion (IVIM) MRI protocol to overcome the limitations from low tendon T2 /T2 * value and low intratendinous blood volume and blood velocity to evaluate tendon microcirculation. Prospective. Sixteen healthy male participants (age 31.0 ± 2.1) were recruited. A stimulated echo readout-segmented echo planar imaging (ste-RS-EPI) IVIM sequence at 3.0T. The feasibility of the proposed ste-RS-EPI IVIM protocol combined with Achilles tendon magic angle effect was evaluated. The sensitivity of the protocol was assessed by an exercise-induced intratendinous hemodynamic response in healthy participants. The vascular origin of the observed IVIM signal was validated by varying the diffusion mixing time and echo time. Two-tailed t-tests were used to evaluate differences (P < 0.05 was considered significant). Consistent with known tendon hypovascularity, the midportion Achilles tendon at baseline showed significantly lower IVIM-derived perfusion fraction (fp ) (3.1 ± 0.9%) compared to the proximal and distal Achilles tendon (6.0 ± 1.8% and 6.1 ± 2.0%, respectively; P < 0.01). Similarly, the midportion Achilles tendon exhibited significantly lower baseline blood flow index (D*×fp ) (40.9 ± 19.2, 18.3 ± 5.3, and 32.0 ± 9.4 in proximal, midportion, and distal Achilles tendon, respectively; P < 0.01). Eccentric heel-raise exercise led to ∼2 times increase of Achilles tendon blood flow in healthy participants. Consistent with its vascular origin, the estimated fp demonstrated a high dependency to IVIM protocol parameters, while the T1 /T2 -corrected absolute intratendinous microvascular blood volume fraction (Vb ) did not vary. Achilles tendon ste-RS-EPI IVIM noninvasively assessed baseline values and exercise-induced changes to tendon microcirculation in healthy tendon. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1690-1699.

Effects of anti-inflammatory (NSAID) treatment on human tendinopathic tissue.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat tendinopathy, but evidence for this treatment is lacking, and little is known regarding effects of NSAIDs on human tendinopathic tendon. This study investigated the effects of NSAID treatment (ibuprofen) on human tendinopathic tendon, with changes in gene expression as the primary outcome, and tendon pain, function, and blood flow as secondary outcomes. Twenty-six adults (16 men, 10 women), diagnosed with chronic Achilles tendinopathy, were randomized to 1-wk treatment with ibuprofen (600 mg ×3/day) (n = 13) or placebo (n = 13) (double-blinded). Ibuprofen content in blood, visual analog scale score for tendon pain at rest and activity, Victorian Institute of Sports Assessment-Achilles (VISA-A) scores for tendon function, tendon thickness (with ultrasonography), and color Doppler were measured before and 1 h after treatment. After the last posttreatment test, a full-width tendon biopsy was taken from the affected area. Real-time-RT-PCR was used to assess expression of collagen I, collagen III, transforming growth factor (TGF-β) isoforms, cyclooxygenase-2 (COX-2), angiopoietin-like 4 (ANGPTL4), and cyclic AMP-dependent transcription factor (ATF3) in tendon tissue. Expression of collagens and TGF-β isoforms showed relatively low variation and was unaffected by ibuprofen treatment. Further, no changes were seen in tendon thickness or VISA-A score. The placebo treatment reduced the color Doppler (in tendon plus surrounding tissue) compared with the ibuprofen group and also increased the perception of pain at rest. In conclusion, there was no indication that short-term ibuprofen treatment affects gene expression in human chronic tendinopathic tendon or leads to any clear changes in tendon pain or function.NEW & NOTEWORTHY Nonsteroidal anti-inflammatory drugs are widely used in the treatment of tendinopathy, but little is known of the effects of these drugs on tendon tissue. We find that 1 wk of ibuprofen treatment has no effect on gene expression of collagen and related growth factors in adult human tendinopathic tendon in vivo (in spite of relatively low levels of variation in gene expression), suggesting that tendinopathic cells are not responsive to ibuprofen.

Diagnostic Performance of Superb Microvascular Imaging and Other Sonographic Modalities in the Assessment of Lateral Epicondylosis.

The aim of this study was to compare the diagnostic performance of different sonographic modalities for diagnosing lateral epicondylosis. A total of 50 symptomatic and 50 asymptomatic common extensor tendons in 44 patients with lateral epicondylosis, and 25 healthy participants were prospectively examined by B-mode sonography, color Doppler imaging, power Doppler imaging, Superb Microvascular Imaging (SMI; Toshiba Medical Systems Corporation, Tokyo, Japan), and strain elastography. We evaluated blood flow in common extensor tendons by using a grading system with color Doppler imaging, power Doppler imaging, and SMI. The diagnostic performance of the modalities was compared. When a cutoff value of hypoechogenicity was used for the mean strain ratio, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy rates were 92.0%, 94%.0, 93.9%, 92.2%, and 93.0%, respectively. When a cutoff point of grade 1 was used, the sensitivity, specificity, PPV, NPV, and accuracy rates were 26.0%, 10.0%, 10.0%, 57.5%, and 63.0, for color Doppler imaging; 40.0%, 10.0%, 10.0%, 62.5%, and 70.0% for power Doppler imaging; and 84.0%, 94.0%, 93.0%, 85.5%, and 89.0% for SMI. When a cutoff value of 3.94 was used for the mean strain ratio, the sensitivity, specificity, PPV, NPV, and accuracy rates were 78.0%, 92.0%, 90.7%, 80.7%, and 85.0%, respectively. A statistically significant correlation was detected between SMI, strain elastography, and visual analog scale scores (P < .001). The combination of SMI and B-mode sonography was found to have excellent diagnostic performance for lateral epicondylosis. Neovascularzation in patients' tendons with lateral epicondylosis was identified much better with SMI compared to color or power Doppler imaging.

Acute effect of running exercise on physiological Achilles tendon blood flow.

Sonographically detectable intratendinous blood flow (IBF) is found in 50%-88% of Achilles tendinopathy patients as well as in up to 35% of asymptomatic Achilles tendons (AT). Although IBF is frequently associated with tendon pathology, it may also represent a physiological regulation, for example, due to increased blood flow in response to exercise. Therefore, this study aimed to investigate the acute effects of a standardized running exercise protocol on IBF assessed with Doppler ultrasound (DU) "Advanced dynamic flow" in healthy ATs. 10 recreationally active adults (5 f, 5m; 29±3years, 1.72±0.12m, 68±16kg, physical activity 206±145minute/wk) with no history of AT pain and inconspicious tendon structure performed 3 treadmill running tasks on separate days (M1-3) with DU examinations directly before and 5, 30, 60, and 120minutes after exercise. At M1, an incremental exercise test was used to determine the individual anaerobic threshold (IAT). At M2 and M3, participants performed 30-minute submaximal constant load tests (CL1 /CL2 ) with an intensity 5% below IAT. IBF in each tendon was quantified by counting the number of vessels. IBF increased in five ATs from no vessels at baseline to one to four vessels solely detectable 5minutes after CL1 or CL2 . One AT had persisting IBF (three vessels) throughout all examinations. Fourteen ATs revealed no IBF at all. Prolonged running led to a physiological, temporary appearance of IBF in 25% of asymptomatic ATs. To avoid exercise-induced IBF in clinical practice, DU examinations should be performed after 30minutes of rest.

Is Achilles tendon blood flow related to foot pronation?

In the etiology of Achilles tendinopathy (AT), it is frequently suggested that excessive pronation causes a vascular constriction of the Achilles tendon, described as the "whipping phenomenon" (Clement et al., 1984). Although previous studies focused on the association between pronation and AT, it is striking that the underlying association between foot pronation and blood flow has not been studied yet. Therefore, the aim of this study was to investigate whether the amount of pronation during running influences the Achilles tendon blood flow. Twenty-five experienced runners, aged 34.5±10.2years, participated in this study. 2D-lower limb kinematics during barefoot and shod running in both frontal and sagittal plane were assessed. Blood flow of the Achilles tendon was measured before and after barefoot and shod running, using the oxygen-to-see device. The results of this study showed a significant effect of eversion excursion on the increase in Achilles tendon blood flow after shod running. More specifically, the more the eversion excursion observed, the lower the increase in blood flow (P=.013). We therefore suggest, in individuals with increased inversion at touchdown and increased eversion around midstance during shod running, that antipronation measures could be useful in both preventing and managing Achilles tendinopathy.

The effect of foot overpronation on Achilles tendon blood supply in healthy male subjects.

The purpose of this study was to investigate Achilles tendon blood flow in individuals with overpronated feet during non-weight- and weight-bearing positions. Achilles tendon blood flow was measured by means of the pulsatility index (PI) and the resistance index (RI) in 15 male individuals with overpronated feet and 15 counterparts with normal feet, using power Doppler ultrasonography (PDI). Achilles tendon ultrasonographic (US) assessment was performed at its musculo-tendinous junction (MTJ), mid-tendon (MT), and osseotendinous junction (OTJ) at a non-weight-bearing relaxed position (RP) and during two-leg stance (TLS) and one-leg upright stance (OLS). PI and RI indices were significantly greater in individuals with overpronated feet compared to individuals with normal feet at the OTJ in OLS position (P<0.01), and at MT in both TLS (P<0.001) and OLS positions (P<0.001). All individuals demonstrated also greater PI and RI indices at MT followed by the OTJ and MTJ in all positions (P<0.001), and in OLS compared to TLS and the RP at the OTJ (P<0.01) as well as at MT and MTJ (P<0.001). The findings of the present study suggest that foot overpronation may affect Achilles tendon blood flow, particularly at mid-tendon, thus enhancing the possibility for injury.

Does Barbed Suture Repair Negate the Benefit of Peripheral Repair in Porcine Flexor Tendon?

Background: Advances in suture material and geometry have fueled interest in barbed suture tenorrhaphy. Theoretically, barbed suture allows better load distribution, smoother gliding under pulleys, and improved tendon blood flow. Minimal data exist on whether barbed tendon repair may benefit from supplementation by a peripheral stitch. The purpose of this study is to determine whether peripheral suture repair increases gap resistance in both conventional and barbed core repairs, increases maximum tensile strength, and fails before or after the core repair. Methods: Porcine flexor tendons were harvested and assigned randomly into 4 groups of 10 of varying suture constructs (3-0 PDS™ or 3-0 V-Loc 180™ core with or without peripheral 5-0 Vicryl™ repair). Core repairs were performed using a modified 4-strand cruciate repair. A servohydrolic tester was used for biomechanical testing of linear 2-mm gap resistance and maximum tensile strength. Results: Peripheral repair improved 2-mm gap resistance in all repairs, regardless of core suture type, conventional (173% increase) or barbed (204% increase). No change in the maximum tensile strength was found in either core suture type with peripheral repair. Peripheral repairs always failed before core repairs, at a significantly higher load of 74.2 ± 20.4 N in barbed versus 57.8 ± 12.2 N (P = .04) in conventional core repairs. Conclusions: The addition of peripheral repair improved gap resistance but not ultimate tensile strength in both conventional and barbed flexor tendon repairs in linear testing. The 4-strand cruciate flexor tendon repairs using barbed suture may require peripheral repair to withstand physiologic loads, as core repair alone using barbed suture was insufficient.