Electrospun Resorbable Drug-eluting Nanofibers Promote Healing of Allograft Tendons

We developed biodegradable drug-eluting nanofibers employing an electrospinning technique, and evaluated their effectiveness on the healing of allograft tendon. Poly-D-L-lactide-glycolide was used as the polymeric material for nanofiber, while doxycycline was selected as the drug for delivery. The in vitro and in vivo drug release profiles were investigated. The biomechanical properties of allograft Achilles tendons repaired using the nanofibers were tested in euthanized rabbits at 2-, 4-, and 6-week time intervals. Histological examination was performed for the evaluation of tissue reaction and tendon healing. The level of postoperative animal activity was also monitored using an animal behavior cage. The experimental results showed that the degradable nanofibers as a vehicle could provide sustained release of doxycycline for over 40 days after surgery with very low systemic drug concentration. Allograft Achilles tendon reconstruction assisted with the drug-loaded nanofibers was associated with better biomechanical properties at 6 weeks post-surgery. In addition, the animals exhibited a better level of activity after surgery. Use of drug-eluting nanofibrous membranes could enhance healing in Achilles tendon reconstruction surgery with allograft.

REHABILITATION PROTOCOL AFTER ACHILLES TENDON RECONSTRUCTION WITH AN AUTOLOGOUS HAMSTRING GRAFT

Introduction One of the treatment options in chronic damage or unsuccessful suturing of the Achilles tendon is a surgical treatment consisting of its reconstruction using the tendon of semitendinosus and gracilis muscle. The multitude of types of reconstruction causes discrepancies in rehabilitation protocols. All of them aim to return to full functional fitness as the ultimate goal. Aim This study aims to present the proprietary rehabilitation protocol after Achilles tendon reconstruction using the tendon of semitendinosus and gracilis muscle. Material and methods The presented rehabilitation program lasts about 12 months and is divided into six stages. Stage I consists of standing up and anticoagulant exercises, and isometric exercise. Stage II, lasting up to 2 weeks after the procedure, consists of the patient’s independent work in the home environment. Stage III, lasting up to 4 weeks, involves learning to walk and putting weight on the limb in a cam Walker. In the third stage, after the postoperative wounds have healed, exercises in water conditions are started. Stage IV, lasting from 4 weeks after the operation, involves loading the limb with support, increasing the range of dorsiflexion motion, and progressive muscle strengthening. Stage V, which lasts up to 8–12 months after surgery, eliminates functional deficits and prepares the patient for a functional biomechanical assessment. Stage VI is the stage of work on the compensation of deficits resulting from the analysis of the results of the functional biomechanical assessment necessary to return to the full sports activity. Results The rehabilitation time, in accordance with the assumptions of the above protocol, is 8–12 months. After this time, the patient should proceed to a functional biomechanical assessment. Discussion and conclusions The rehabilitation protocol presented by our team describes in detail the stages of post-operative rehabilitation after Achilles tendon reconstruction with a hamstring graft. It provides the conditions necessary for the patient to meet before starting the next phase and returning to sport. Our requirements are consistent with the assumptions available in the scientific base. Keywords: Achilles tendon reconstruction, return to sport, rehabilitation program.