BACKGROUND: The intracompartmental septum in the first extensor compartment in patients with de Quervain's disease has been associated with disease development and prognosis. However, with the exception of surgical exploration, there is no way of detecting the septum. QUESTIONS/PURPOSES: We evaluated the accuracy of sonography for identifying the intracompartmental septum in the first extensor compartment in patients with de Quervain's disease using surgical findings as the reference standard. PATIENTS AND METHODS: We performed surgical release of the first extensor compartment in 43 wrists of 40 patients who were unresponsive to nonoperative treatment. In each case, a sonographic evaluation was performed before surgery by a radiologist and the sonographic and surgical findings were compared. RESULTS: Sonography identified the intracompartmental septum in 19 of the 19 septum-present wrists and absence of the septum in 23 of the 24 septum-absent wrists. The sensitivity of sonography was 100% (95% confidence interval, 80%-100%), its specificity 96% (95% confidence interval, 78%-100%), accuracy 98% (95% confidence interval, 87%-100%), positive predictive value 95% (95% confidence interval, 74%-100%), and negative predictive value 100% (95% confidence interval, 83%-100%). Sonography also identified septum-like structures in 15 of 37 (41%) asymptomatic contralateral wrists. CONCLUSIONS: Sonography is useful for detecting the intracompartmental septum in the first extensor compartment in patients with de Quervain's disease. LEVEL OF EVIDENCE: Level I, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
BACKGROUND: The intracompartmental septum in the first extensor compartment in patients with de Quervain's disease has been associated with disease development and prognosis. However, with the exception of surgical exploration, there is no way of detecting the septum. QUESTIONS/PURPOSES: We evaluated the accuracy of sonography for identifying the intracompartmental septum in the first extensor compartment in patients with de Quervain's disease using surgical findings as the reference standard. PATIENTS AND METHODS: We performed surgical release of the first extensor compartment in 43 wrists of 40 patients who were unresponsive to nonoperative treatment. In each case, a sonographic evaluation was performed before surgery by a radiologist and the sonographic and surgical findings were compared. RESULTS: Sonography identified the intracompartmental septum in 19 of the 19 septum-present wrists and absence of the septum in 23 of the 24 septum-absent wrists. The sensitivity of sonography was 100% (95% confidence interval, 80%-100%), its specificity 96% (95% confidence interval, 78%-100%), accuracy 98% (95% confidence interval, 87%-100%), positive predictive value 95% (95% confidence interval, 74%-100%), and negative predictive value 100% (95% confidence interval, 83%-100%). Sonography also identified septum-like structures in 15 of 37 (41%) asymptomatic contralateral wrists. CONCLUSIONS: Sonography is useful for detecting the intracompartmental septum in the first extensor compartment in patients with de Quervain's disease. LEVEL OF EVIDENCE: Level I, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.