title: Compression therapy promotes proliferative repair during rat Achilles tendon immobilization.
abstract: Achilles tendon ruptures are treated with an initial period of immobilization, which obstructs the healing process partly by a reduction of blood circulation. Intermittent pneumatic compression (IPC) has been proposed to enhance tendon repair by stimulation of blood flow. We hypothesized that daily IPC treatment can counteract the deficits caused by 2 weeks of immobilization post tendon rupture. Forty-eight Sprague-Dawley SD) rats, all subjected to blunt Achilles tendon transection, were divided in three equal groups. Group A was allowed free cage activity, whereas groups B-C were immobilized at the operated hindleg. Group C received daily IPC treatment. Two weeks postrupture the rats were euthanatized and the tendons analyzed with tensile testing and histological assessments of collagen organization and collagen III-LI occurrence. Immobilization significantly reduced maximum force, energy uptake, stiffness, tendon length, transverse area, stress, organized collagen diameter and collagen III-LI occurrence by respectively 80, 75, 77, 22, 47, 65, 49, and 83% compared to free mobilization. IPC treatment improved maximum force 65%, energy 168%, organized collagen diameter 50%, tendon length 25%, and collagen III-LI occurrence 150% compared to immobilization only. The results confirm that immobilization impairs healing after tendon rupture and furthermore demonstrate that IPC-treatment can enhance proliferative tendon repair by counteracting biomechanical and morphological deficits caused by immobilization.
authors.affiliation: Orthopaedic Laboratory, Department of Molecular Medicine and Surgery, M1:02, The King Gustav V Research Building, Karolinska University Hospital 171 76 Stockholm, Sweden. nikos.schizas@ki.se
authors.forename: Nikos
authors.initials: N
authors.lastname: Schizas
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Therese
authors.initials: T
authors.lastname: Andersson
authors.forename: Anna
authors.initials: A
authors.lastname: Fahlgren
authors.forename: Per
authors.initials: P
authors.lastname: Aspenberg
authors.forename: Mahmood
authors.initials: M
authors.lastname: Ahmed
authors.forename: Paul W
authors.initials: PW
authors.lastname: Ackermann
mesh_terms: D000125:Achilles Tendon / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D001835:Body Weight; D002370:Casts, Surgical; D024061:Collagen Type III / Q000378:metabolism; D007103:Immobilization / Q000009:adverse effects*; D048228:Intermittent Pneumatic Compression Devices; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013708:Tendon Injuries / Q000503:physiopathology* / Q000628:therapy*; D013718:Tensile Strength / Q000502:physiology; D014945:Wound Healing / Q000502:physiology
chemical_list: D024061:Collagen Type III