Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of the article is prohibited. Flexor digitorum accessorius longus muscle in resistant clubfoot patients: introduction of a new sign predicting its presence Samir Shaheen a , Haitham Mursal b , Mohamed Rabih b and Ashok Johari c Clubfoot, talipes equino varus (TEV), is a common congenital foot anomaly. Some cases are resistant to conservative treatment. Many causes of resistance have been reported, among these, the presence of anomalous muscles; however, the effect of the presence of anomalous muscles on the outcome of conservative management is not well studied. These aberrant muscles are discovered during the extensive surgical release as an abnormal finding. The aim of this work is to study the demographic characteristics of patients with resistant TEV that necessitated extensive soft tissue release at Sudan Clubfoot Clinic and to document the prevalence of flexor digitorum accessorius longus (FDAL) muscle in a large series of clubfoot patients treated by extensive surgery: posteromedial release. Also, we introduce a new observation as an indication by which the surgeon can predict the presence of FDAL. On the basis of an observation that there is a special posture of the big toe in extension in relation to other flexed toes associated with the presence of FDAL, records of patients of clubfoot treated by extensive surgery between 2007 and 2012 at the Sudan Clubfoot Project were reviewed. Demographic characteristics were studied. Only patients with idiopathic TEV were included. Resistant clubfeet necessitated extensive release in 261 patients, 197 males and 64 females. Their ages ranged between 1 day and 15 years at presentation. FDAL muscle was found in 48 patients (54 feet) out of 261 patients (411 feet, 13.14%). In 46 of the 48 patients (95.8%), the presence of the FDAL could be predicted by a sign. FDAL is prevalent in 13% of resistant TEV cases requiring extensive soft tissue release, and the surgeon can expect resistant clubfoot and predict the presence of the FDAL in over 95% before he operates by observing the Samir–Adam sign. J Pediatr Orthop B 24:143–146 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Journal of Pediatric Orthopaedics B 2015, 24:143–146 Keywords: flexor digitorum accessorius longus muscle, resistant clubfoot, Samir–Adam sign a Department of Orthopaedics & Traumatology, Faculty of Medicine, University of Khartoum, b Ministry of Health, Khartoum, Sudan and c Children’s Orthopaedic Centre, Mumbai, Maharashtra, India Correspondence to Samir Shaheen, MD, JMHPE, Department of Orthopaedics & Traumatology, Faculty of Medicine, University of Khartoum, PO Box 102 Khartoum, 11111, Sudan Tel: +00 249 183 778570; fax: +00 249 183771211; e-mail: drsshaheen@meduofk.net Introduction Congenital talipes equino varus (TEV) or congenital clubfoot is a common foot abnormality in childhood [1]. It affects males more than females and it is one of the most common problems encountered in paediatric orthopae- dics [2]. The aetiology of idiopathic clubfoot remains elusive [3]. Vascular deficiencies, environmental factors, factors related to amniotic fluid, abnormal muscle inser- tion, in-utero positioning and genetic factors have been reported to play a role [4]. Pathological anatomy of clubfoot has been well studied and described as tight posteromedial soft tissue structures as well as bone changes in the tarsal bones [5]. It also lists four components of deformity: cavus, adduction, varus and equinus. These four components are summarized as CAVE [6]. In the majority of cases, the Ponseti method of treatment is successful; however, some cases are resistant. These resistant cases are encountered in some idiopathic TEV or could be associated with arthrogryposis or meningo- myelocele [4]. Resistant cases may also be encountered in cases of anatomical abnormalities such as an aberrant tendo-Achilles [6]. In other series, flexor digitorum accessorius longus (FDAL) muscle was reported to be associated with clubfoot, which required extensive soft tissue release for correction [3,7]. The reported prevalence of FDAL varies between 5 and 13% [8]. Gupta et al. [9] reported four cases of accessory soleus muscle in association with clubfoot. FDAL is not only associated with resistant clubfeet; it has been reported that patients with FDAL and peroneocalcaneus internus muscles can present with tarsal tunnel syn- drome [8]. Studies of the association of FDAL with clubfoot are rare, and the abnormal muscle is noted only at the time of surgical correction [3]. The presence of FDAL has also been reported in association with a clubfoot patient with Nager syndrome [10] and in association with familial idiopathic clubfoot [3]. In this study, we report 48 patients with FDAL in asso- ciation with resistant clubfoot that required extensive soft tissue release. In over 95% of these patients (46 of 48 patients), we could predict the presence of the anomalous Original article 143 1060-152X Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/BPB.0000000000000129