Accuracy of the Pisiform Boost Test for the Diagnosis of Triangular Fibrocartilage Complex Tears in the Wrist - Pisiform Boost Test

Background: A retrospective study was conducted to evaluate the diagnostic accuracy of a novel examination technique, the ‘Pisiform Boost Test,’ in diagnosing a triangular fibrocartilage complex (TFCC) tear. Methods: Wrist arthroscopies performed between ۲۰۱۱-۲۰۲۱ were retrospectively reviewed. Patients’ clinical records were evaluated to determine the result of the Pisiform Boost Test during clinical examination and TFCC tear within the body of the TFCC as seen at wrist arthroscopy. The Pisiform Boost Test is performed by first assessing for ulna fovea pain on passive ulna deviation of the wrist and then assessing pain while the clinician applies digital pressure over the pisiform and passive ulna deviation. Results: The pisiform Boost test was found to have a Sensitivity of ۹۱% (۹۵% CI, ۸۱ – ۹۷%) and a Specificity of ۳۳% (۹۵% CI, ۱۴-۵۹%) for the diagnosis of TFCC tears. Positive predictive value of ۸۳%, a negative predictive value of ۵۰%, and an accuracy of ۷۸%. A chi-square test of independence was performed to examine the relation between a Positive Pisiform Boost Test and an arthroscopy-confirmed TFCC tear. The relation between these two variables was statistically significant, x۲ (۱, N = ۸۲) = ۶.۴۵۵۱, P=.۰۱۱۰۶۴. Conclusion: The Pisiform Boost Test demonstrates high sensitivity for TFCC tears (۰.۹۱). Specificity (۰.۳۳) is similar to that in the ulnar grinding test. Therefore, we propose this test be utilized with additional special tests for ulna-side wrist pain to allow clinicians to build a diagnostic picture, aiding decision-making and patient information.Level of evidence: IV