Methylene blue use for preventing postoperative adhesion after flexor digitorum profundus tendon repair in chickens (experimental study)

IV.ABSTRACT Methylene Blue Use for Preventing Postoperative Adhesion After Flexor Digitorum Profundus Tendon Repair in Chickens (Experimental Study) Aim: Our hands are the most important assistant organ that enables us to do essential activities in our daily lives. The most active part of the upper extremity is the least protected part of the upper limb and, therefore, injury in this area is the most common [1,2]. About 20% of all patients presenting to the emergency department have hand injuries. İnjuries to the flexor tendon occur very often because the tendons are very close to the skin surface [4]. Postoperative adhesion after tendon repair adversely affects the functional outcome in the healing process [12]. The development of adhesion in the soft tissues surrounding the wound region and peritendinically on the healing tendon causes functional deficiency. Peritendinous adhesion formation remains the most important complication of tendon surgery despite the development of surgical techniques and materials, a better understanding of the tendon physiology and the evolution of rehabilitating therapies [13,14]. In several experimental and clinical studies of different departments, such as General Surgery and Obstetrics and Gynecology, there was found to be evidence that methylene blue reduces adhesion [17,18,19]. From this point of view, the use of methylene blue should be applied in order to prevent or decrease the adherence of the tendon to the surrounding tissues and epithelium. Postoperative adhesion is a major complication of orthopedic surgery and after tendon repair. The tendon repair cannot function even if surgical repair is successful. We aimed to see and test the use of methylene blue after repair. Materials and Methods: Our study consisted of 2 groups, group A and B. Each group had 16 chickens. There was a total of 32 chickens with an average weights ranging from 2000-2500 grams. The chickens were 6 months old. 8 chickens were randomly selected from 16 chickens in each group. They were evaluated histopathologically and biomechanically at the 4th week and the remaining 8 chickens at the 6th week. Group A Control; 30 mg / kg ketamine and 1 ml 2% prilocaine were used for the digital block. After the skin preparation, the left foot 2 and 3 fingers were cut by a 2 cm longitudinal incision and the flexor tendon sheath was incised, and the flexor digitorum profundus was released.These released tendons were sutured with 5-0 v prolene using modified Kessler's technique. The peritendinous sheath and skin were sutured and the extremity operated with circular cast was immobilized. Group B Working; 30 mg / kg ketamine and 1 ml 2% prilocaine were used for the digital block. After the sterile skin preparation, the left foot 2 and 3 fingers were cut by a 2 cm longitudinal incision and the flexor tendon sheath was incised , and the flexor digitorum profundus was released. These released tendons were sutured with 50 prolene using modified Kessler's technique. Then 0.25 cc % 1 methylene blue was injected around the repaired tendon and the tendon sheath and skin were sutured. The operated limb was immobilized with circular cast. Results: In group B after 4 weeks, the amount of adhesion was less histopathological and biomechanically than group A. After 6 weeks, the amount of adhesion was found to be less histopathological and biomechanically in group B than in group A. There was a difference in favor of group B in the 6th week between group B and 4th week in group B in terms of adhesion. Conclusion: It was observed that methylene blue had antiseptic, antimicrobial, antiinflammatory and antioxidant effects and it, also, decreased adhesion formation after tendon repair. Keywords: Methylene blue, Tendon healing, flexor tendon adhesion, Chicken flexor tendon