en Anatomical Sciences Anatomical Sciences Original Research Original Research <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-style:italic"><b>&nbsp;&nbsp;</b><b><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp; Background: </span></span></b><span style="font-size:9.0pt"><span style="font-style:normal">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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-style:italic"><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp;&nbsp; <b>Methods:</b> 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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-style:italic"><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp;&nbsp; <b>Results:</b> Patients were mainly women (24 [67.6%]), and the mean age was 50.43 &plusmn; 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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-style:italic"><b><span style="font-size:9.0pt"><span style="font-style:normal">&nbsp;&nbsp; Conclusion:</span></span></b><span style="font-size:9.0pt"><span style="font-style:normal"> 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.</span></span></span></span></span></span></span></span><br> <span style="font-size:13pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="text-autospace:none"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-style:italic"><span style="font-size:9.0pt"><span style="font-style:normal"></span></span></span></span></span></span></span></span><br> &nbsp; Anatomic Variation, De Quervain Disease, Tendinopathy 990 993 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-7306-2&slc_lang=en&sid=1 Alireza Pahlavansabagh pahlevansabagh@gmail.com 200319475328460073280 200319475328460073280 No Bone and Joint Reconstruction Research Center, Department of Orthopedic Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mohammad Soleimani mohammad.soleimani.md@gmail.com 200319475328460073281 200319475328460073281 No Department of Epidemiology, School of Public Health, Iran University of Medical Sciences, Tehran, Iran Alireza Ghaznavi ghaznavi.ar@iums.ac.ir 200319475328460073282 200319475328460073282 No Bone and Joint Reconstruction Research Center, Department of Orthopedic Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Mahsa Roshanipour mahsa.roshanipour1373@gmail.com 200319475328460073283 200319475328460073283 No Bone and Joint Reconstruction Research Center, Department of Orthopedic Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Farbod Yousefi yousefi.farbod@mayo.edu 200319475328460073284 200319475328460073284 No Department of Orthopedics and Trauma Surgery, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Seyed Nima Taheri Taheri.ni@iums.ac.ir 200319475328460073285 200319475328460073285 Yes Bone and Joint Reconstruction Research Center, Department of Orthopedic Surgery, School of Medicine, Iran University of Medical Sciences, Tehran, Iran