Prevalence of Septated First Dorsal Compartment Among Iranian Patients with De Quervain Tenosynovitis

Background: A septum in the first extensor compartment and variation of abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons affect the development and treatment of the de Quervain disease. This study aimed to determine the prevalence of septum and the number of APL and EPB tendons in Iranian surgical de Quervain patients. Methods: In this case series, we evaluated 37 consecutive wrists from September 2019 to April 2020 that were evaluated and surgically explored by the same senior surgeon; and the number of tendons and the existence of septum were recorded. Results: Patients were mainly women (24 [67.6%]), and the mean age was 50.43 ± 16.42 years. Seven (18.9%) patients had one, 23 (62.2%) had two, and 7 (18.9%) patients had three APL tendons. All patients had EPB tendons, 34 (91.9%) had 1 EPB tendon, and 3 (8.1%) had 2 EPB tendons. A septum was observed in 23 (62.2%) patients. Conclusion: The most functional variation in Iranian patients consists of 2 APL tendons and 1 EPB tendon. Also, most affected wrists had a septum in the first extensor compartment.