Dominique Pioletti

Biomechanical consequences of humeral component malpositioning after anatomical total shoulder arthroplasty

HYPOTHESIS We hypothesized that the malpositioning of the humeral component can preclude the long-term success of anatomical total shoulder arthroplasty. The goal of this study was to evaluate the mechanical consequences of superior and inferior malpositioning of the humeral head. MATERIALS AND METHODS A numerical musculoskeletal model of the shoulder joint allowing natural humeral head translation was used to simulate a loaded abduction movement controlled by muscular activation. An inferior and superior malpositioning of 5 mm were compared to an optimal positioning. Impingements, articular contact pattern, and cement stress were evaluated. RESULTS Inferior malpositioning of the humeral head induced impingement and limited the abduction level, while superior malpositioning increased the subluxation risk. Both inferior and superior malpositioning increased the stress level within the cement mantle. DISCUSSION This numerical study highlights the importance of an anatomical reconstruction of the glenohumeral surfaces for the success rate of anatomical total shoulder arthroplasty.

Impact of partial-thickness tears on supraspinatus tendon strain based on a finite element analysis

Keywords: rotator cuff ; tendon modelling ; numerical model Reference EPFL-CONF-202510doi:10.1080/10255842.2014.931514View record in Web of Science Record created on 2014-10-23, modified on 2017-05-25

A model for micromotion-induced fluid flow at the bone-implant interface

Keywords: total joint replacement ; primary stability ; micromotion ; interstitial fluid flow Reference EPFL-CONF-202509doi:10.1080/10255842.2014.931107View record in Web of Science Record created on 2014-10-23, modified on 2017-05-25

A method to measure glenoid wear in 3D

A precise knowledge of the glenoid wear state and the global joint status is of prime importance for an optimal treatment of glenohumeral osteoarthritis. To this end, Walch et al. (1999) proposed a classification that is widely accepted. This classification is based on a 2D measure of the glenoid version and subluxation of the humeral head from CT images (Friedman et al. 1992). Although this method uses a reproducible criterion to choose the level of the axial plane (Friedman et al. 1992; Hoenecke et al. 2009), the measure is purely 2D and depends on the scapula and humerus position within the CT. This can induce measurement error and does not account for bone wear out of this plane. Habermeyer et al. (2006) proposed a 2D method to estimate the glenoid inclination in the frontal plane, in complement to Walch’s classification. Hoenecke et al. (2009) used 3D reconstruction to measure the direction of maximum wear on the glenoid and pointed out that a 2D method underestimated the data in more than 50% of the cases. The other proposed methods to overcome this issue require a complete reconstruction of the entire scapulae, and do not fully account for the complex 3D surface of the glenoid. In this study, an extension of the 2D Walch method to an objective 3D measure is proposed, which is applicable to regular clinical CT containing only the lateral part of the scapula.

Shoulder muscle forces during abduction with subscapularis deficiency after total shoulder arthroplasty

Keywords: shoulder ; muscle force ; fem ; Replacement ; Joint Reference EPFL-CONF-170875doi:10.1080/10255842.2011.591527View record in Web of Science Record created on 2011-12-16, modified on 2017-05-10