Abstract
Background: The research objectives of the 5- and 10-year assessments of the Finnish Degenerative Meniscal Lesion Study (FIDELITY) are two-fold: 1) to assess the long-term efficacy of arthroscopic partial meniscectomy (APM) in adult (age 35 to 65 years) patients with a degenerative meniscus tear, and 2) to determine the respective effects of APM and degenerative meniscus tear on the development of radiographic and clinical knee osteoarthritis (OA).
Methods and Design: FDELITY is an ongoing multi-centre, randomized, participant and outcome assessor blinded, placebo-surgery controlled trial of 146 patients. This statistical analysis plan (SAP) article describes the overall principles for analysis of long-term outcomes (5- and 10-year follow-ups), including how participants will be included in each analysis, the primary and secondary outcomes and their respective analyses, adjustments for covariates, and the presentation of the results. In addition, we will present the planned sensitivity and subgroup analyses.
Discussion: To study whether APM (resection of torn meniscus tear) per se accelerates or delays the development of knee osteoarthritis in patients with an arthroscopically-verified degenerative tear of the medial meniscus, we are carrying out pre-registered long-term (5- and 10-year) follow-up of our placebo-surgery controlled FIDELITY trial according to statistical principles outlined in detail in this document. We have also outlined the analyses intended to assess our second primary objective, the long-term efficacy of APM on knee symptoms and function.