Intraindividual Doppler Flow Response to Exercise Differs Between Symptomatic and Asymptomatic Achilles Tendons

Abstract

ObjectiveThis study investigated intraindividual differences of intratendinous blood flow (IBF) in response to running exercise in participants with Achilles tendinopathy.DesignThis is a cross-sectional study.SettingThe study was conducted at the University Outpatient Clinic.ParticipantsSonographic detectable intratendinous blood flow was examined in symptomatic and contralateral asymptomatic Achilles tendons of 19 participants (42 ± 13 years, 178 ± 10 cm, 76 ± 12 kg, VISA-A 75 ± 16) with clinically diagnosed unilateral Achilles tendinopathy and sonographic evident tendinosis.InterventionIBF was assessed using Doppler ultrasound “Advanced Dynamic Flow” before (Upre) and 5, 30, 60, and 120 min (U5–U120) after a standardized submaximal constant load run.Main Outcome MeasureIBF was quantified by counting the number (n) of vessels in each tendon.ResultsAt Upre, IBF was higher in symptomatic compared with asymptomatic tendons [mean 6.3 (95% CI: 2.8–9.9) and 1.7 (0.4–2.9), p < 0.01]. Overall, 63% of symptomatic and 47% of asymptomatic Achilles tendons responded to exercise, whereas 16 and 11% showed persisting IBF and 21 and 42% remained avascular throughout the investigation. At U5, IBF increased in both symptomatic and asymptomatic tendons [difference to baseline: 2.4 (0.3–4.5) and 0.9 (0.5–1.4), p = 0.05]. At U30 to U120, IBF was still increased in symptomatic but not in asymptomatic tendons [mean difference to baseline: 1.9 (0.8–2.9) and 0.1 (-0.9 to 1.2), p < 0.01].ConclusionIrrespective of pathology, 47–63% of Achilles tendons responded to exercise with an immediate acute physiological IBF increase by an average of one to two vessels (“responders”). A higher amount of baseline IBF (approximately five vessels) and a prolonged exercise-induced IBF response found in symptomatic ATs indicate a pain-associated altered intratendinous “neovascularization.”

In Achilles Tendinopathy the Symptomatic Tendon Differs from the Asymptomatic Tendon While Exercise Therapy Has Little Effect on Asymmetries—An Ancillary Analysis of Data from a Controlled Clinical Trial

“…Although leg dominance can affect inter-limb tendon CSA asymmetry, laterality was not related to the side of injury in our study, making it unlikely that the larger CSA was caused by more intense loading. Furthermore, there is compelling evidence confirming our results of more pronounced tendon vascularity in tendinopathic Achilles tendon [18][19][20][21]. Indeed, vascular alterations in tendinopathy are well known [62] and are reported to correlate with severity [34], although a considerable proportion of tendinopathy patients (i.e., 37%) does not show any sign of neovascularization [63], questioning increased vascularization as a single valid clinical sign for all patients [64].…”

“…While a certain degree of limb asymmetry can be considered as non-pathological, pronounced inter-limb differences particularly in Achilles tendon CSA and vascularization appear to be a hallmark of Achilles tendinopathy. Enlarged tendinopathic Achilles tendons have been reported in many studies [18][19][20][21][59][60][61] and may be caused by inflammation related edema. Localized fusiform tendon swelling has been reported previously in midportion Achilles tendinopathy [61].…”

“…Furthermore, higher tendon strain and reduced tendon stiffness for the tendinopathic Achilles tendon [17] have been reported. Increased tendon thickness and hypervascularization was reported in symptomatic Achilles tendons in runners [18,19] and in a general patient population [20,21]. These findings indicate that there are pronounced differences in mechanical, morphological, and functional (i.e., muscle strength or jump performance) properties between the symptomatic and the asymptomatic Achilles tendon, which may be linked to injury etiology or progression.…”

Efficiency of rehabilitation in limb asymmetries of achilles tendinopathy female patients

“…The high-load bunch played out a profoundly serious one-sided strength preparing convention comprising of five arrangements of four plantar flexor withdrawals at 90% of isometric greatest wilful constrictions held for three seconds followed by three seconds of rest each and with 1-min in the middle between sets with the impacted leg. [21][22][23][24][25][26][27][28][29][30] This convention was executed four times each week with a portable input fitted sling which has recently been depicted. 31 The dissemination of meetings in the span of seven days was picked independently.…”

Validation of New Semi-Automated Ultrasound Image Analysis Method for Assessing Vascular Resistance in Musculoskeletal Tissues

“…The use of Doppler ultrasound in the assessment of musculoskeletal pathologies is becoming increasingly common (1,2). Doppler ultrasound can be used to localize areas of increased blood flow and quantify color pixels, which can provide clinically important information, more accurate diagnoses, and assessments of response to treatment (3).…”