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

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.