The accuracy of MRI diagnosis of thumb ulnar collateral ligament injuries over physical examination in clinical decision-making for surgery

Purpose: This retrospective study assessed whether magnetic resonance imaging (MRI) confers a diagnostic or therapeutic advantage over clinical examination in managing thumb ulnar collateral ligament (UCL) injuries and evaluated its accuracy in lesion characterization. Materials and methods: We reviewed 96 patients undergoing surgical repair over a ten-year period, 43 of whom had preoperative MRI and 53 who did not. Results: While MRI exhibited high sensitivity (97%) and specificity (80%) for detecting UCL pathology, its accuracy for differentiating lesion subtypes was only moderate (72–84%). No appreciable difference was noted between MRI and non-MRI cohorts in the proportion of indication-appropriate (57% vs. 45%) or surgeries potentially amenable to conservative treatment (43% vs. 55%). Conclusions: Thus, MRI did not influence the indication for surgery beyond what was determined by a meticulous physical examination. A thorough clinical assessment remains the mainstay, reserving MRI for diagnostically challenging scenarios or when detailed anatomical visualization is necessary.