Variations of the long extensor tendon to the thumb are very rare.
Materials and Methods
We present three cases in which there was a supernumerary long extensor tendon to the thumb. In all three cases, the supernumerary tendon emerged from the fourth dorsal compartment and had a parallel course to the extensor pollicis longus.
Results
Details of the anomalies are described along with a meta-analysis of relevant literature. A classification system of these anomalies is also proposed.
Abu-HijlehMFExtensor pollicis tertius: an additional extensor muscle to the thumb. Plast Reconstr Surg.1993;92(2):340–3.
2.
BeattyJDRemediosDMcCulloughCJAn accessory extensor tendon of the thumb as a cause of dorsal wrist pain. J Hand Surg [Br].2000;25(1):110–1.
3.
CavdarSSehirliUThe accessory tendon of the extensor indicis muscle. Okajimas Folia Anat Jpn.1996;73(2–3):139–42.
4.
ChiuDTSupernumerary extensor tendon to the thumb: a report on a rare anatomic variation. Plast Reconstr Surg.1981;68(6):937–9.
5.
CulverJEJrExtensor pollicis and indicis communis tendon: a rare anatomic variation revisited. J Hand Surg [Am].1980;5(6):548–9.
6.
CohenBEHaberJLSupernumerary extensor tendon to the thumb: a case report. Ann Plast Surg.1996;36(1):105–7.
7.
GaulkeR (2001) The Extensor Pollicis et Indicis: an accessory or rudimentary deep extensor tendon to the thumb? Variants—frequency—clinical relevance. Handchir Mikrochir Plast Chir Sep;33(5):310–320. Review. German.
8.
GonzalezMHWeinzweigNKayTGrindelSAnatomy of the extensor tendons to the index finger. J Hand Surg [Am].1996;21 (6):988–91.
9.
KomiyamaMNweTMToyotaNShimadaYVariations of the extensor indicis muscle and tendon. J Hand Surg [Br].1999;24 (5):575–8.
SawaizumiTNannoMItoHSupernumerary extensor pollicis longus tendon: a case report. J Hand Surg [Am].2003;28 (6):1014–7.
12.
SteichenJBPetersenDPJunctura tendinum between extensor digitorum communis and extensor pollicis longus. J Hand Surg [Am].1984;9(5):674–6.
13.
YoshidaYAnatomical studies on the extensor pollicis et indicis accessorius muscle and the extensor indicis radialis muscle in Japanese. Okajimas Folia Anat Jpn.1995;71(6):355–63.
