Circulating substance P levels and shoulder joint contracture after arthroscopic repair of the rotator cuff

Francesco Franceschi ¹, Umile Giuseppe Longo ¹, Laura Ruzzini ¹, Fabrizio Battistoni ², Sergio Morini ³, Giordano Dicuonzo ², Nicola Maffulli ^4* and VINCENZO Denaro ¹

¹ Department of Orthopaedics, Campus Biomedico University, Via Longoni, 83, 00155 Rome, Italy
² Department of Laboratory Medicine and Microbiology, Campus Biomedico University, Rome, Italy
³ Department of Surgical Pathology, Campus Biomedico University, Via Longoni, 83, 00155 Rome, Italy, Italy
⁴ Keele University School of Medicine, United Kingdom

^* To whom correspondence should be addressed. E-mail: osa14{at}keele.ac.uk.

Accepted 8 November 2007

Abstract

Objective: To determine the plasma levels of substance P (SP) in patients with postoperative stiffness after arthroscopic rotator cuff repair.<br> Design: Plasma samples were obtained at 15 months from surgery from 2 groups of patients who underwent arthroscopic repair of a rotator cuff tear. In Group 1, 30 subjects (14 men and 16 women, mean age: 64.6 years, range 47 to 78) with shoulder stiffness 15 months after arthroscopic rotator cuff repair were recruited. In Group 2, 30 patients (11 men and 19 women, mean age: 57.8 years, range 45 to 77) were evaluated 15 months after successful arthroscopic rotator cuff repair. Immunoassays were performed with commercially available assay kits to detect the plasma levels of SP.<br> Results: The mean plasma levels of SP in patients with postoperative stiffness were significantly greater than those in the control group (81.06 ± 27.76 versus 23.49 ± 5.64, P < 0.05). <br> Conclusions: The plasma concentrations of substance P in patients with shoulder stiffness after arthroscopic rotator cuff repair are higher compared to plasma levels of SP in patients with a good postoperative outcome. The neuronal up-regulation of SP shown in the plasma of patients with post operative shoulder stiffness may underlay not only the symptoms of adhesive capsulitis, but also its development.