Characteristics of Intratendinous Microcirculation Shortly After an Achilles Rupture and Subsequent Treatment Outcomes

Background

Early microcirculatory responses after experimental tenotomy are critical to the healing of tendons and their ultimate tensile strength. The effects of changes in microcirculation on the outcomes of tendon healing, however, have not been determined.

Objectives

To assess microcirculation values in injured Achilles tendons in the first 3 months after surgical repair and to correlate the inter-limb microcirculatory changes with functional outcomes at 3 and 6 months after surgery.

Design

Case-control study.

Setting

A university sports physiotherapy laboratory.

Participants

Thirteen subjects (median age: 45 years; range: 34.8-51.9 years) with a repaired Achilles tendon were recruited.

Methods or Intervention

Surgical repair.

Main Outcome Measurements

Measurements were obtained at 1, 2, 3, and 6 months after surgery. Bilateral measurements of tendon microcirculation (total hemoglobin THb] and oxygen saturation StO₂]) were recorded at the first 3 time points, whereas outcome measures of a Taiwan Chinese version of the Victorian Institute of Sport Assessment Scale-Achilles questionnaire, one-leg hopping distance, the star excursion balance test, and the heel raise index were conducted at the third and fourth time points. Correlations between the inter-limb microcirculatory changes, eg, between the measurements at 2 months and 1 month (2-1) after surgery, at 3 months and 2 months (3-2) after surgery, and at 3 months and 1 month (3-1) after surgery, and the outcome measures were investigated.

Results

Compared with the noninjured tendons, the repaired Achilles demonstrated greater THb (at 1, 2, and 3 months; P = .017, .008, and .012 respectively) and StO₂ (at 3 months; P = .017). Furthermore, the THb2-1 and THb3-2, StO₂ 2-1, and StO₂ 3-2 showed correlations with the heel raise index, differences in the star excursion balance test and one-leg hopping distance between the noninjured leg and injured leg, and Taiwan Chinese version of the Victorian Institute of Sport Assessment Scale-Achilles questionnaire scores (rho ?0.921 to 0.855).

Conclusions

Changes in the inter-limb microcirculation shortly after Achilles repair were correlated with subsequent symptoms and functional symmetry.

Level of Evidence

III