Deep Flexor Tendon Repairs: Analysis of current concepts, Introduction of improvements, Establishment of new techniques.

摘要

The patient’s ability to master everyday living tasks is strongly dependent on the utility of healthy functional hands. Therefore the restoration of hand function after tendon injuries is of utmost importance. Tendon injuries are common, especially lacerations in zone II. In this area flexor tendons follow a complicated anatomy and are difficult to repair.Consequently this thesis focuses on the research of tendon repairs in zone II and aims to improve repair quality and ultimately final functional outcome for the patient.To approach this topic the author of this thesis firstly analysis current concepts of tendon repair research models, secondly investigates common tendon repair techniques and improvements of these techniques and thirdly introduces new techniques for repair of deep flexor tendons in zone II.This thesis consists of ex vivo and in vivo experiments, which all build on another. Main results of these experiments are as follows:•In regards to comparability to human tendons, sheep tendons are better tendon surrogates as pig tendons if used in ex vivo laboratory experiments. •When focusing on gapping resistance, "locking loop" repair configurations for tendon repairs are not substantially different to "grasping loop" configurations, and only "cross-locks", as used in the Adelaide repair technique, deserve the adjective description "locking". •The current gold standard of tendon repairs, the Adelaide repair, produces better repair stability if performed with larger cross locks. •The author's interlocking modification of the Adelaide repair can further improve the Adelaide repair's stability. •In an ex vivo setting, the author's new tendon repair concept, the knotless 3D barbed suture tendon repair, produces superior repair stability than the Adelaide repair. •The turkey tendon model is the first tendon model that replicates human anatomy and tendon sizes and can be used in ex vivo as well as in vivo tendon repair experiments. •In an in vivo tendon repair scenario, the use of the knotless 3D barbed suture tendon repair with resorbable barbed sutures produces inferior repair stability compared to the Adelaide repair, but improves functional outcomes.This thesis presents new insights into tendon repair research from a surgical and biomechanical point of view.The use of the novel unknotted barbed suture repair method did show superior results in ex vivo experiments but barb resorption in the in vivo experiments caused high failure rates. Nevertheless, there is a probability that with the development of more stable small barbed suturing materials in the near future it will be possible to further improve deep flexor tendon repairs using this novel repair technique.