Experimental Repair of Rotator Cuff Rupture in the Dog

Abstract

The course of the repair of the rotator cuff rupture has not been fully clarified experimentally in comparison with that of other tendons. Revascularization and remodelling of surgically made canine rotator cuff rupture were studied microangiographically.Twenty-four shoulders of twelve adult mongrel dogs were used. The study was divided into two groups: group I. Resection of the supraspinatus tendon. group II. Tendon suturing to bone after cuff resection. The dogs were killed at regular intervals and specimens including the cuff and the greater tuberosity were obtained and observed microangiographically. Microangiographic studies were also performed in six shoulders of three non-operaed dogs to clarify the normal distribution of the blood vessels in the rotator cuff.In normal canine rotator cuff, three main arteries contributed the arterial supply of the supraspinatus tendon; the suprascapular artery, the cranial circumflex humeral artery and the caudal circumflex Numeral artery. The supraspinatus tendon insertion was relatively hypovascular in its intratendinous portion.In group I, wide scar tissue formed in the gap was hypervascular and the vascular pattern was entirely different from that of normal supraspinatus tendon at twenty-four weeks.In group II, tendo-osseous junction underwent a process of progressive reconstruction, though proliferation of blood vessels still remained at twenty-four weeks.