Impact of Collagen Crosslinking on Dislocated Human Shoulder Capsules-Effect on Structural and Mechanical Properties.

Jean-David Werthel,Francis Berenbaum,Jessem Landoulsi,Pauline Cornette,Xavier Houard,Vincent Dupres,Geoffroy Nourissat,Ilhem Lilia Jaabar

doi:10.3390/ijms23042297

Abstract

Classical treatments of shoulder instability are associated with recurrence. To determine whether the modification of the capsule properties may be an alternative procedure, the effect of crosslinking treatment on the structure and mechanical properties of diseased human shoulder capsules was investigated. Joint capsules harvested from patients during shoulder surgery (n = 5) were treated or not with UV and/or riboflavin (0.1%, 1.0% and 2.5%). The structure and the mechanical properties of the capsules were determined by atomic force microscopy. The effect of treatments on cell death was investigated. Collagen fibrils were well-aligned and adjacent to each other with a D-periodicity of 66.9 ± 3.2 nm and a diameter of 71.8 ± 15.4 nm in control untreated capsules. No effect of treatments was observed on the organization of the collagen fibrils nor on their intrinsic characteristics, including D-periodicity or their mean diameter. The treatments also did not induce cell death. In contrast, UV + 2.5% riboflavin induced capsule stiffness, as revealed by the increased Young’s modulus values (p < 0.0001 for each patient). Our results showed that the crosslinking procedure changed the biomechanics of diseased capsules, while keeping their structural organisation unchanged at the single fibril level. The UV/riboflavin crosslinking procedure may be a promising way to preserve the functions of collagen-based tissues and tune their elasticity for clinically relevant treatments.

Highlights

Instabilities of the glenohumeral joint are the frequent disorders of young sportive patients
We investigate the combined effect of UV irradiation and riboflavin, a procedure adapted from crosslinking treatments performed on cornea and sclera disorders [11], on the structure and mechanical properties of diseased shoulder capsules harvested from patients during surgery
Since the most noticeable effect on mechanical properties seems to be related to the UV + RH treatment, and that this treatment is the one expected to induce collagen crosslinking, Figure 3 presents individual comparisons obtained for the five studied patients with the UV + RH treatment

Summary

Introduction

Instabilities of the glenohumeral joint are the frequent disorders of young sportive patients. Anatomic lesions like Bankart, HAGL (humeral avulsion glenohumeral ligament) or mid substance tears of the capsule and labrum are well known and are routinely treated by surgical procedures. A simple plication or direct repair could not treat the instability efficiently because surgery is acting mostly on the soft tissues involved in the procedure [1]. Thermal capsulorrhaphy has been developed and used to treat many different types of shoulder instability, but the efficacy of the thermal treatment cannot be confirmed [3]. This thermal shrinkage can be carried out using radiofrequency or laser devices [4]. There is a real unmet need to efficiently treat shoulder instability

Methods

Results

Conclusion