Long‐term morphology of a healing bone–tendon interface: a histological observation in the sheep model

Abstract

The purpose of this study was to examine and describe the sequence of events involved in long-term biological reconstruction of a tendon-bone interface following surgical reattachment. Patellar tendon re-attachment in the adult sheep was used to investigate and describe the biological components involved in healing and repair of a tendon enthesis. Light microscopy was used to describe the healing morphology at time intervals of 8, 12, 26, 52 and 104 weeks. By 8 weeks a collagen continuum was observed between the tendon and bone. Over time this fibrous bridge became anchored into the original tissues (tendon and bone), with the resultant enthesis resembling more a fibrous rather than the original fibrocartilagenous enthesis. The associated collagen fibrils between the two tissues gradually changed in morphology over time to reflect the fibres seen in the original tendon tissue. The fibrous tissue of the forming enthesis remained hypercellular when compared with the controls. The resultant long-term morphology may be a reflection of functional adaptation rather than anatomical replication.

Repair of fresh patellar tendon rupture: tension regulation at the suture line

“…Therefore, healing of the avulsed tendon comprises healing of the tendinous tissue and tendon-bone junction. Lack of mechanical stimulation is detrimental to healing progress at both interfaces [1,4,6,[16][17][18].…”

“…The utility of absorbable devices in tension regulation has been mentioned in several studies [16,17,20], yet it is not attributed to anyone. The reinforcement device in this study is made of Vicryl (polyglactin 910) suture, which has initial tensile strength equal or superior to nonabsorbable sutures [3,20].…”

“…During this period, the reinforcement suture has lost its tensile strength [5]; thereby, the recommended biomechanical loading [1,4,17,18] is possible. A programme of straight leg rising and active flexion exercise is instituted.…”

“…However, better healing is possible, but requires timely mechanical loading of the repaired tendon [1,4,6,9,[16][17][18]. According to current knowledge the appropriate time point during the healing process for loading to start has been identified [1,18], but there is a need to find a practical tool for initiation of the biomechanical loading.…”

Innovative Strategies for Treatment of Soft Tissue Injuries in Human and Animal Athletes

“…As mentioned in the introduction, one major obstacle in tendon ruptures is the fact that tendon-bone junctions cannot easily be reconstructed to provide secure healing: Especially fibrocartilaginous osteotendinous junctions do not regenerate properly and all attempts for generation of such an enthesis with four zones have failed so far and resulted in fibrous enthesis only [33]. And, an enthesis in the wrong anatomic location entails limited mechanical strength.…”