title: Matrix metalloproteases and their inhibitors are altered in torn rotator cuff tendons, but also in the macroscopically and histologically intact portion of those tendons.
abstract: We evaluated whether matrix metalloproteases and their inhibitors are involved in extracellular matrix remodelling and degradation of chronic rotator cuff tears. Tendon samples were harvested from 13 patients who underwent arthroscopic repair of a rotator cuff tear. Supraspinatus specimens were harvested en bloc from the arthroscopically intact middle portion of the tendon, more than 1 cm lateral to the torn edge, from the lateral edge of the tear, and from the superior margin of the macroscopically intact subscapularis tendon, used as control. The collagenases, the stromelysins, and the tissue inhibitors of metalloprotease arrays were analyzed blindly by multiplex sandwich ELISA in each specimen. Histological evidence of tendinopathy was present in all patients with a rotator cuff tear, but not in the macroscopically intact subscapularis tendon. There were significantly increased levels of MMP 1, MMP 2, MMP 3, TIMP-1, and TIMP-2 in all specimens examined, including the macroscopically intact portion of the supraspinatus tendon and the subscapularis (control specimens). The levels of specific matrix metalloproteases and their inhibitors are altered in torn rotator cuff tendons, but also in the macroscopically and histologically intact tendons. These changes extended medially to the site of tendon tear, and to other tendons.
authors.affiliation: Shoulder and Elbow Surgery Unit: Istituto Clinico Humanitas Rozzano, Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Castagna
authors.affiliation: Shoulder and Elbow Surgery Unit: Istituto Clinico Humanitas Rozzano, Milan, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Cesari
authors.affiliation: Department of Orthopedic and Traumatology, F. Miulli Hospital. Acquaviva delle Fonti, Bari, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Garofalo
authors.affiliation: Orthopaedics Clinic, School of Medicine, Marche Polytechnic University, Ancona, Italy ; Department of Molecular Pathology and Innovative Therapies, School of Medicine, Marche Polytechnic University, Ancona, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gigante
authors.affiliation: Shoulder and Elbow Surgery Unit: Istituto Clinico Humanitas Rozzano, Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Conti
authors.affiliation: Shoulder and Elbow Surgery Unit: Istituto Clinico Humanitas Rozzano, Milan, Italy.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Markopoulos
authors.affiliation: Centre for Sports and Exercise Medicine, Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Mile End Hospital, London, UK ; Department of Physical and Rehabilitation Medicine, University of Salerno, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Maffulli
keywords: gene expression; outcome; rotator cuff; surgery