Morphometric Measurement and Types of Articular Facets on the Talus and Calcaneus in an Anatolian Population

Abstract

Anatomical variations in terms of ligamentous attachments, articulations and bony morphology are common in the subtalar region. The shape of the articular facets of the talus and calcaneus and their relationship to each other are important for joint function and surgical procedures. In this study an assessment of the morphology of the articular facets of the talus and calcaneus, in an Anatolian population, was undertaken. 49 tali and 57 calcanei from Anatolian adults of unknown gender were examined. The types of articular facets on the talus and calcaneus were determined using the following classification: Type A1, the distance between the anterior and middle facets was less than 2 mm; Type A2, the distance between the anterior and middle facets was 2-5 mm; Type A3, the distance between the anterior and middle facets was more than 5 mm; Type A4, there was only one articular facet; Type B1, the separation between the anterior and middle facets was not complete; Type B2, separation of the anterior and middle facets was present; Type C, no separation between the anterior, middle and posterior facets was present, i.e. there was one articular facet. In addition, the anteroposterior length and width of the talus and calcaneus, together with the width, length and depth of sulcus tali and sulcus calcanei were determined. Left and right tali, respectively, displayed the folowing types of articular facet: A1, 0 %, 0 %; A2, 0 %, 3,4 %; A3, 0 %, 0 %; A4, 0 %, 0 %; B1, 60 %, 51,8 %; and B2, 40 %, 44.8 %. Articular facets on left and right calcanei, respectively, were: A1, 10 %, 7.4 %; A2, 10 %, 14.8 %; A3, 16.7 %, 11.1 %; A4, 3.3 %, 3.7 %; B1, 30 %, 22.2 %; B2, 30 %, 40.8 %. The length and width of left and right tali were 50.5 +/- 3.81 mm and 39.5 +/- 2.97 mm, and 53.1 +/- 4.38 mm and 39.3 +/- 3.66 mm, respectively. The width, length and depth of left and right sulcus tali were: 5.2 +/- 1.09 mm, 21.7 +/- 2.73 mm and 5.7 +/- 0.84 mm, and 6.1 +/- 2.05 mm, 21.1 +/- 3.66 mm and 5.7 +/- 1.52 mm, respectively. For left and right calcanei length and width were; 76.1 +/- 5.44 mm 44.0 +/- 3.97 mm, and 75.7 +/- 6.76 mm and 45.9 +/- 4.21 mm, respectively. The width, length and depth of left and right sulcus calcanei were: 6.4 +/- 1.19 mm, 31.9 +/- 2.76 mm and 4.0 +/- 0.81 mm, and 5.5 +/- 1.00 mm, 32.4 +/- 3.23 mm and 4.4 +/- 1.05 mm, respectively. The articular facets on both the talus and calcaneus in the Anatolian population studied was predominantly type B. This observations is similar to previous reports conducted in America, India and Africa, but differ from those undertaken in Europe. A knowledge of variations of the articular facets of the talus and calcaneus provides a valuable road map for orthopaedic surgeons, as well as others involved in foot rehabilitation.