Partial interosseous ligament tears of the wrist: Difficulty in utilizing either primary or secondary MRI signs

Purpose: Prior reports on scapholunate ligament (SLL) and lunotriquetral li gament (LTL) tears have evaluated complete tears, As these complete tears h ave markedly different biomechanical manifestations and surgical considerat ions than do partial tears, we evaluated the accuracy of MR and the usefuln ess of secondary MR signs to diagnose partial interosseous ligament tears. Method: Fifty wrists in 50 patients underwent arthroscopy following 1.5 T M R. Images were evaluated by two independent blinded observers for normal or partially torn SLL and LTL and for three secondary signs potentially seen as mechanical sequelae of tears: osseous offset, arc disruption, or focal o steoarthritis. Results: Arthroscopically. there were 16 SLL and 14 LTL partial tears. Accu racy of primary MR signs of partial tears was lower than that described in the literature for complete tears [sensitivity/specificity (kappa) = 0.56/0 .56 (0.12)-SLL, 0.31/0.76 (0.13)-LTL]. Secondary signs showed low sensitivi ty but high specificity, particularly for LTL tears: arc disruption [0.17/0 .83 (0.43)-SLL, 0,0/1.00 (1.0)- LTL], focal osteoarthritis [0,32/0.78 (0.18 )-SLL, 0.11/0.91 (0.12)-LTL]. and focal osseous offset [0.39/0.75 (0.10)-SL L, 0.26/0.93 (0.39)-LTL]. Additionally, there was poor interobserver consis tency for both primary and secondary signs. Conclusion: The sensitivity of morphologic evaluation for diagnosing partia l intercarpal ligament tears, particularly those of the LTL, is limited. Se condary signs increase specificity but have low sensitivity, and with the e xception of arc disruption, all signs had poor interobserver agreement.