The accessory navicular (AN) is an accessory ossicle anatomically located on the medial side of the foot, proximal to the navicular and continuous with the tibialis posterior tendon. It is occasionally a source of pain and local tenderness. Knowledge of the AN and its morphological variations can help identify the source of a patient's symptoms and prevent misinterpreting them as fractures. Foot radiographs from 1,240 patients who presented in two centers with chronic foot pain, or persistent pain developed after trauma, were retrospectively reviewed to determine the incidence and variations of the AN in relation to gender. The AN was found in 20.9% (259/1240). Among 259 feet with AN, Type 1 was identified in 25.4% (66/259), Type 2 in 42.4% (110/259) (20.0% (52/259) Type 2 A and 22.4% (58/259) Type 2B), and Type 3 in 32.0% (83/259). After 13 patients with incomplete medical records had been excluded, the remaining records showed that foot pain was associated with an AN in 10.6% of patients (26/246). In 1.2% of cases, two additional ossicles were found proximal to the navicular, possibly the result of multiple ossification centers that did not unite at the time of development. Patient symptomatology was related to the presence of an AN in 2% of patients with chronic foot pain. The AN could vary morphologically. Our data can enhance our diagnostic skills in detecting these ossicles. Clin. Anat. 30:436-444, 2017. © 2017 Wiley Periodicals, Inc.

Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations.

Objectives: To establish the normal values of Quadriceps angle(Q angle) in Jordanians according to gender and bilaterality within-subject symmetry in both extremities, and to examine its association with anthropometric measures (body height, weight, body mass index, pelvic width, and waist to hip circumference ratio).

The aim of our study was to determine the prevalence and the anatomical variations of the posterolateral tubercle of talus in relation to sex on CT imaging. A total of 1478 ankle CT scans was retrospectively reviewed for the different anatomical variants of the posterolateral tubercle of talus, the type and size of os trigonum. Normal sized lateral tubercle was found in 46.1 %, an enlarged posterolateral tubercle (Stieda's process) in 26.1 %, os trigonum in 20.5 % and almost absent tubercle in 7.3 %. A statistically higher prevalence of Stieda's process was found in males while os trigonum was higher in females (p<0.05). Among feet with os trigonum, 25.7 % were non-articulating and identified as a separate bone located posterior to the posterolateral tubercle of talus and 74.3 % of os trigonum were identified as fused to the posterolateral tubercle by synchondrosis or syndesmosis. Additionally, 17.5 % of os trigonum were associated with intact lateral tubercle, 53.5 % were considered as part of the lateral tubercle and 29.0 % were without a lateral tubercle. According to its size, 22.8 % of os trigonum were smaller than 0.5 cm, 55.4 % were between 0.5 and 1cm, and 21.8 % were larger than 1 cm. No significant differences were found between the different types/sizes of os trigonum according to gender (p>0.05). The posterolateral tubercle of talus and its accessory ossicle, the os trigonum, could vary morphologically. The data of this study could be helpful in understanding the clinical problems that could be associated with some of these variants.