Accelerated Achilles tendon healing with interleukin-1 receptor antagonist protein in rabbits

The current study describes the use of interleukin-1 receptor antagonist protein (IL-1Ra) as a possible strategy for optimizing tendon healing and repair by presenting histologically visible changes in rabbit Achilles tendon tissue after longitudinal tenotomy. The study was carried out on 26 Californian rabbits divided into two equal groups. One was the experimental IRAP (interleukin-1 receptor antagonist) group and the second one was the PBS (purified buffered saline) group. The PBS group was the control group. After longitudinal tenotomy in both groups of rabbits, in the IRAP group IL-1Ra was applied locally, whereas PBS was applied in the control group. IL-1 concentration in Achilles tendon tissue was measured with an ELISA IL-1 rabbit kit. Local application of IL-1Ra resulted in 2.5-fold lower IL-1 tissue concentration and prevented cytokine cascade activation and its proinflammatory effects. Consequently, it prevented chronic tendon inflammation and improved Achilles tendon healing in rabbits. Histological changes in tendon tissue samples were evaluated by Bonar scale score with statistically significant differences between groups (P ≤ 0.01).

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  • Friedrich T, Schmidt W, Jugmichel D, Horn LC, Josten CH. Histopathology in rabbit Achilles tendon after operative tenolysis (longitudinal fiber incision). Scand J Med Sci Sports 2011; 11: 4-8.
  • Maffulli N, Longo UG, Denaro V. Movin and Bonar scores assess the same characteristics of tendon histology. Clin Orthop Relat Res 2008; 466: 1605-1611.
  • Maffulli N, Barrass V, Ewen SW. Light microscopic histology of Achilles tendon ruptures. A comparison with unruptured tendons. Am J Sports Med 2000; 28: 857-863.
  • Tallon C, Maffulli N, Ewen SW. Ruptured Achilles tendons are significantly more degenerated than tendinopathic tendons. Med Sci Sports Exerc 2011; 33: 1983-1990.
  • Astrom M, Rausing A. Chronic Achilles tendinopathy: a survey of surgical and histopathologic findings. Clin Orthop 1995; 346: 151-164.
  • Leadbetter WB. Cell-matrix response in tendon injury. Clin Sports Med 1992; 11: 533-578.
  • Movin T, Gad A, Reinholt FP, Rolf C. Tendon pathology in longstanding achillodynia: biopsy findings in 40 patients. Acta Orthop Scand 1997; 68: 170-175.
  • Jozsa LG, Kannus P. Histopathological findings in spontaneous tendon ruptures. Scand J Med Sci Sports 1997; 7: 113- 118.
  • Khan KM, Maffulli N. Tendinopathy: an Achilles heel for athletes and clinicians. Clin J Sport Med 1998; 8: 151-154.
  • Nirschl RP, Pettrone F. Tennis elbow: the surgical treatment of lateral epicondylitis. J Bone Surg 1979; 61: 832-839.
  • Kraushaar B, Nirschl RP. Tendinosis of the elbow (tennis elbow). J Bone Joint Surg Am 1999; 81: 259-278.
  • Naito M, Ogata K. The blood supply of the tendon with a paratendon. An experimental study using hydrogen washout technique. Hand 1983; 15: 9-14.
  • Kvist M, Jozsa L, Jarvinen M. Vascular changes in the ruptured Achilles tendon and paratendon. Int Orthop 1992; 16: 377-382.
  • Carr AJ, Norris SH. The blood supply of the calcaneal tendon. J Bone Joint Surg Br 1989; 71: 100-101.
  • Kuschner SH, Orlando CA, Mckellop HA, Sarmiento A. A comparison of the healing properties of rabbit Achilles tendon injuries at different levels. Clin Orthop Relat Res 1991; 272: 268-273.
  • Movin T. Aspects of aetiology, pathoanatomy and diagnostic methods in chronic mid-portion achillodynia. PhD, Karolinska Institute, Stockholm, Sweden, 1998.
  • Kvist M. Achilles tendon overuse injuries. Ann Univ Turku 1991; 87: 1-121.
  • Maffulli N, Ewen SW, Waterston S, Reaper J, Barrass V. Tenocytes from ruptured and tendinopathic Achilles tendons produce greater quantities of type III collagen than tenocytes from normal Achilles tendons. An in vitro model of human tendon healing. Am J Sports Med 2000; 28: 499-505.
  • Khan KM, Cook JL, Bonar F, Harcourt P, Astrom M. Histopathology of common tendinopathies. Update and implications for clinical management. Sports Med 1999; 27: 393-408.