Author's Reply

It was with great interest that I read the letter to the editor of Drs. Spies and Unglaub concerning our article “Efficacy of Magnetic Resonance Imaging and Clinical Tests in Diagnostics of Wrist Ligament Injuries: A Systematic Review.” I agree with their comments. The radiologic and clinical diagnostics of triangular fibrocartilage complex (TFCC) injury is challenging. The interpretation of the important peripheral attachment tears of the TFCC with magnetic resonance imaging (MRI) is even more difficult than central tears. The small sizes and oblique orientations of the radioulnar ligaments, ulnar attachments, and ulnolunate and ulnotriquetral ligaments make visualization of the important peripheral structures much more difficult than that of the central disks. It has been generally accepted that appropriate parameter settings of MRI are most important for high accuracy. In 2013 Ringler proposed an MRI strategy for the wrist ligaments to increase accuracy in diagnosing wrist ligament injuries, including magnetic strength of 1.5 T or greater; dedicated wrist coils; field of view (FOV) of 10 cm or less; slice thickness of 2 mm or less; matrix of 384 × 256 or greater; and MRI sequences including T1, fat-saturated proton density or T2-weighted fast-spin-echo (FSE). However, in our opinion, most important is an experienced, dedicated radiologist working closely with the hand surgeon. The article concerning quality rating of MRI regarding TFCC injuries by Hahn et al. is of great interest and also impressive when it comes to the number of patients. Unfortunately, it did not match our strict inclusion criteria in terms of language and data available. Furthermore, I agree that clinical experience and a standardized clinical examination protocol are essential in diagnostics of wrist ligament injuries. However, in 1995 LaStayo and Howell showed that provocative wrist tests proved to be more effective in predicting the absence of injury than its presence. In our systematic review, Prosser et al. reached a borderline-cutoff negative predictive value (NPV) of 94% for clinical provocative tests of the lunotriquetral ligament, but for the TFCC, the NPV was only 55%. In summary, negative results of MRI or clinical provocative tests are still unable to safely rule out the possibility of clinically relevant tears to the TFCC and other wrist ligaments, which makes further diagnostic evaluation with wrist arthroscopy necessary.