Quantitative assessment of blood vessels of the human Achilles tendon: an immunohistochemical cadaver study.

BACKGROUND

The pathogenesis of Achilles tendon rupture remains unclear, but vascular patterns may play an important role. Hypoxia is considered to be an important factor in the aetiology of tendon degeneration.

METHODS

Statements from the literature regarding the vascularization of the Achilles tendon are controversial. We determined the vascular density of the Achilles tendon using a new method involving antibodies against laminin, a component of the basement membrane.

RESULTS

The blood supply of the Achilles tendon mainly arose from the anterior paratenon of the tendon from which vessels run into the tendon. The proximal part of the tendon was supplied by a recurrent branch of the posterior tibial artery, while the distal part of the tendon was vascularized by the rete arteriosum calcaneare, supplied by the fibular and posterior tibial arteries. An avascular area could be seen close to the insertion of the tendon to the calcaneus. Three regions with different vascular density could be determined in the Achilles tendon. The distal part of the Achilles tendon had a vascular density of 56.6 vessels/cm(2). In the middle part of the tendon, the vascular density was much lower: 28.2 vessels/cm(2). The proximal part of the tendon had a vascular density of 73.4 vessels/cm(2).

CONCLUSION

The reduced vascularization in the tendon waist may be a predisposing factor for degeneration and spontaneous rupture of the human Achilles tendon.