STG Tendon Transfers 2022 Student.pdf

Tendon Healing/Repair/Transfers Sean T. Grambart DPM FACFAS Objectives Identify Identify the microscopic and macroscopic structure of tendon. Identify Identify of the phases of tendon healing. Identify Identify tendon suture techniques and tendon-bone anchoring devices. Demonstrate Demonstrate knowl...

Tendon Healing/Repair/Transfers Sean T. Grambart DPM FACFAS Objectives Identify Identify the microscopic and macroscopic structure of tendon. Identify Identify of the phases of tendon healing. Identify Identify tendon suture techniques and tendon-bone anchoring devices. Demonstrate Demonstrate knowledge of basic tendon transfers and indications Demonstrate Demonstrate knowledge of the length-tension relationship (Blix curve). 2 Tendon Histology Tendon Anatomy Epitenon (Synovial Layer) surround the tendon Paratenon (areolar tissue) continuous with epitenon contains nerve and blood vessels Mesotenon is epitenon + paratenon Tendon sheath is present when tendon angles around structures Paratenon vs. Tendon Sheath Paratenon: Continuous with epitenon Contains nerve and blood vessels Allows tendon to glide Only found on tendons with straight pull, ie: Achilles tendon Tendon Sheath: Tubular structure prevents bowstringing Lined with synovial cells Allows tendon to glide like a piston in a cylinder Epitenon and inner layer of sheath make up mesotenon Contains blood and lymphatics VASCULAR SUPPLY TO TENDON 3 SOURCES Musculotendinous junction Bone/periosteum Paratenon Impact Phases of Tendon Healing Inflammatory Proliferative Remodeling Phases of Tendon Healing: Phase I Impact: Moment of injury Activation of complement cascade Vasoconstriction Platelet aggregation (intrinsic and extrinsic pathway activation) Phases of Tendon Healing: Phase II Inflammatory Cellular infiltration jelly-like serous and granulation tissue at gap zone PMN’s and macrophages Acidic environment with low oxygen tension stimulates fibroblast and collagen production Phases of Tendon Healing: Phase III Proliferative: Fibroblasts bridge gap zone Collagen synthesis Return of function Phases of Tendon Healing: Phase IV Remodeling: Healing Systematic organization of collagen bundles with anatomic orientation TENDON SURGERY!! Side to Side Anastomosis Tendon Fixation End to End Tendon to Bone End to End Repair 15 End to End Bunnell Repair Moderate strength, pull is longitudinal Disadvantage: can constrict vascular supply to tendon End to End Lateral Trap Repair Designed after chinese finger trap Grips outside of tendon Avoids constricting microcirculation 17 Kessler Easy to perform Can do repair percutaneously 18 End to End Krackow Repair Interlocking weave stitch Good tensile strength Doesn’t constrict microcirculation 19 Side to Side Anastomosis Tendon Fixation End to End Tendon to Bone Side to Side Anastomosis Most physiologic pull Problem is slippage, so crosshatch or rough up tendons to promote fibrous union Used when doing a tendon lengthening 22 Side to Side Anastomosis Tendon Fixation End to End Tendon to Bone TENDON TRANSFERS In-Phase Out-of-Phase Definitions Tendon transfer Detachment of a tendon of a functioning muscle at its insertion and then its relocation to a new insertion or attachment Tendon transposition Rerouting of the course of a normal muscle tendon without detachment to assist other functions Muscle-tendon transplantation The detachment of a muscle tendon at both its origin and its insertion and moving it to a new location along with its neurovascular support structures constitute a muscle–tendon transplantation Tendon suspension Tendon procedures designed to support a structure (AKA tenosuspension) Two main purposes?? Principles of Tendon Tendon to be transferred ideally should be phasic Transfers Adequate range of movement within the joint on which the Eliminate any deforming force Augment weak function transferred muscle will act should be remaining Muscle must have adequate power. Lose at least 1 grade of power with the transfer Transfer only muscle tendon units with a power of M4 or M5** Recommend the transfer even for a weak muscle if it is considered to be the deforming force After the transfer, the tendon should run in a straight course 26 Side to Side Anastomosis Tendon Fixation End to End Tendon to Bone TENDON TRANSFERS In-Phase Peroneus Longus to Brevis Tendon Transfer In-phase Transfer 29 Side to Side Anastomosis Tendon Fixation End to End Tendon to Bone Trephine plug Interference screw Tendon to Bone Repair Button anchor Screw and washer Suture anchor Button Anchor Screw and Washer Three Hole Suture Suture Anchors 36 36 Trephine Plug/Osseous Tunnel/Interference Screw Interference screw TENDON TRANSFERS Out-ofPhase PT Thru Interosseous 40 40 Tendons in General Fasten tendon under zero tension Physiology of Tension: Blix Curve Blix determined that there is a certain muscle length at which contractile force is strongest and most efficient Tension developed by muscle is related to length of the muscle when it contracts Muscle produces greatest force at 120% resting length Zero tension is found to be at 60% resting length 42 Thank You 43