Pairwise association of upper extremity musculoskeletal conditions: large population investigation from PERSIAN cohort study

BACKGROUND: People with one area of upper extremity musculoskeletal conditions (UEMSCs) may have other. We aim to determine how frequent is the ipsilateral coexistence of common UEMSCs apparent on interview and examination. METHODS: This is a large population cross-sectional study conducted as part of the PERSIAN cohort study int Mashhad University of Medical Sciences (MUMS). The study aimed to evaluate individuals for symptoms and signs of the following conditions: carpal tunnel syndrome (CTS), lateral epicondylitis (LE), trapeziometacarpal osteoarthritis (TMC OA), DeQuervain’s tendinopathy, trigger digit (TD), ganglion cyst, and rotator cuff tendinopathy (RCT). The primary outcomes of the study are (1) to determine the side-specific relative risk of each UEMSC coexisting with the second condition, and (2) to identify predictive factors of each UEMSC using side-specific multivariate logistic regression analysis. RESULTS: We conducted a study involving 4737 individuals from the staff of MUMS and found significant pairwise associations among UEMSCs on a side-specific basis. Women had more chance of having DeQuervain’s disease (β = 6.3), CTS (β = 3.5), ganglion cyst (β = 2.5), TMC OA (β = 2.3), and RCT (β = 2.0). Each condition (dependent variable) was associated with others (predictors) as follows: CTS: RCT (β = 5.9), TMC OA (β = 4.7), TD (β = 2.9), and LE (β = 2.5). TMC OA: LE (β = 6.4), TD (β = 5.4), RCT (β = 4.3), and CTS (β = 4.1). LE: RCT (β = 8.1), TMC OA (β = 6.4), and CTS (β = 2.5). DeQuervain’s disease: TD (β = 13.6), RCT (β = 4.5), and LE (β = 3.8). TD: CTS (β = 8.8), ganglion cyst (β = 7.6), DeQuervain’s disease (β = 5.7), and TMC OA (β = 4.3). RCT: LE (β = 5.8), TMC OA (β = 5.5), CTS (β = 5.2), and DeQuervain’s disease (β = 4.3). Ganglion cyst: TD (β = 4.8). CONCLUSION: Our study reports significant increased frequency of the UEMSCs among patients who already have one of the diseases, in a large sample size study. Level of Evidence Level II (Differential Diagnosis/Symptom Prevalence Study).