Factors Influencing Outcome After Shoulder Arthroplasty (FINOSA Study): Protocol of a Prospective Longitudinal Study With Randomized Group Allocation (Preprint)

Abstract

BACKGROUND There is an increasing need for evidence based post-operative rehabilitation strategies to optimize patient outcome. Knowledge of potential prognostic factors could steer the development of screening and rehabilitation protocols and could result in better treatment outcomes and higher patient satisfaction. OBJECTIVE Therefore, the primary objective of this study is to investigate which potential prognostic factors predict baseline shoulder pain and function and its evolution in the first two years following surgery, in patients with total shoulder arthroplasty. The secondary objective is to investigate which potential prognostic factors predict baseline quality of life and its evolution in the first two years following surgery. METHODS To reach the aims of this project, a prospective longitudinal study, running from January 2020 to March 2025, will be carried out with a follow-up of 48 months. We will study factors such as shoulder function, patient expectations, psychosocial factors, lifestyle factors, sling wear, soft tissue integrity, and physiotherapy treatment. Descriptive statistics will be used to describe the patient population characteristics. Based on literature review, expert opinion and univariate analyses potential prognostic factors will be chosen as covariates. A mixed regression model for repeated measures will be used to assess both the evolution of the SPADI score within persons from baseline over time and the differences in evolution between subjects. Correlation analyses will be used to investigate associations between the other outcome measures such as the Constant and Murley Score, shoulder range of motion, shoulder muscle strength, and proprioception and the primary outcome measure, the Shoulder Pain And Disability Index. Potential prognostic factors not included in the model will be presented in a descriptive manner. RESULTS Data collection started in January 2020. In April 2023 the sample size was reached. Data collection is ongoing. CONCLUSIONS Knowledge of potential prognostic factors will have implications towards better rehabilitation strategies of patients after total shoulder arthroplasty. CLINICALTRIAL ClinicalTrials.gov NCT04258267 February 6th, 2020