Case report: bilateral occurrence of a chondroepitrochlearis muscle.

The chondroepitrochlearis is an extremely rare muscular anomaly. Bergman et al. (1988) in their book on anatomical variations refer to ‘costoepitrochlearis, chondroepitrochlearis, or chondrohumeralis’ and describe the anomaly as a muscular slip which arises from one or more ribs, crosses the axilla, and inserts into the median intermuscular septum or medial humeral epicondyle. The phylogenetic significance of the muscle has received attention (Landry, 1958; Chiba et al. 1983; Bergman, 1991), and case reports with ulnar nerve entrapment and restriction of arm movements (FitzGerald, 1935–1936; Voto & Weiner 1987; Lin, 1988; Spinner et al. 1991) have emphasised its clinical relevance.