Microcirculation after Achilles tendon rupture correlates with functional and patient‐reported outcomes

Abstract

Patients with acute Achilles tendon rupture (ATR) display an extended healing process with varying clinical outcome. Poor microcirculatory blood flow has been suggested to be a significant factor for the healing process. However, whether microcirculation may predict healing outcome has been mostly unknown. Therefore, we investigated whether blood flow in the Achilles tendon may be associated with patient‐reported and functional outcomes after ATR. In vivo laser‐Doppler flowmetry was used to assess microvascular blood flow bilateral in the Achilles tendons, during post‐occlusive reactive hyperemia, of nine patients with acute total ATR at 2 weeks post‐operatively. At 3 months post‐operatively, patient‐reported outcome was assessed using Achilles tendon Total Rupture Score (ATRS). At 1 year a uniform outcome score, Achilles Combined Outcome Score (ACOS), was obtained by combining validated, independent, patient‐reported (ATRS), and functional outcome (heel‐rise test) measures. An improved combined patient‐reported and functional outcome, ACOS, at 1 year was significantly correlated with higher maximum blood flow (r=.777, P=.040) in the injured limb. Furthermore, enhanced patient‐reported outcome, ATRS, at 3 months, was associated with an elevated ratio of maximum to resting blood flow (r=.809, P=.015) in the uninjured limb. Blood flow in early tendon healing is associated with long‐term patient‐reported and functional outcomes after ATR. The microcirculatory blood flow of both the healing and contralateral Achilles tendon seems to determine the healing potential after injury.

Intravoxel incoherent motion (IVIM) imaging in human achilles tendon

“…Furthermore, neovascularization is known to occur after tendon injury and is closely related to pain . Therefore, accurate assessment of the Achilles tendon microvasculature and microcirculation is of high clinical relevance to monitor tendinopathy progression and tendon repair …”

“…Both invasive and noninvasive laser Doppler flowmetries (LDF) have observed higher intratendinous blood flow in symptomatic Achilles tendons compared to healthy tendons . However, invasive LDF requires probe insertion, has a limited measurement region (∼1 mm 3 ), and can only provide relative measurement with unexplained estimation bias . Noninvasive LDF provides a larger measurement region and improves the sensitivity depth by increasing the separation between the source and the probe, but is susceptible to contamination from high blood flow in the paratenon .…”

“…[5][6][7] Therefore, accurate assessment of the Achilles tendon microvasculature and microcirculation is of high clinical relevance to monitor tendinopathy progression and tendon repair. 8 Several techniques have been applied in the clinical setting to measure Achilles tendon blood flow. Both invasive and noninvasive laser Doppler flowmetries (LDF) have observed higher intratendinous blood flow in symptomatic Achilles tendons compared to healthy tendons.…”

“…9 However, invasive LDF requires probe insertion, has a limited measurement region ($1 mm 3 ), and can only provide relative measurement with unexplained estimation bias. [8][9][10] Noninvasive LDF provides a larger measurement region and improves the sensitivity depth by increasing the separation between the source and the probe, but is susceptible to contamination from high blood flow in the paratenon. 11 Recently, ultrasound (US)-based techniques such as color Doppler US (CDUS) and power Doppler US (PDUS) have been used to detect neovascularization in tendinopathy.…”

Achilles tendinopathy – pathophysiology: state of the art

“…Mechanisms speculated to contribute to tendinopathy with age are blood circulation,27 cellular senescence, ageing stem cell population, reactive oxygen species and formation of advanced glycation end-product (AGE) crosslinks 28. Further knowledge of age-related changes in tendon disorders is crucial to understanding increased incidence of tendon injuries in the ageing population.…”