Accessory head of flexor pollicis longus muscle in fetuses and adult cadavers and its relation to anterior interosseous nerve

This study was conducted to examine the accessory head of flexor pollicis longus muscle (ahFPL) and its relation with the anterior interosseous nerve (AIN) in human fetuses and adult cadavers. Ninety fetus forearms and 52 adult cadaver forearms were dissected to evaluate the incidence, morphology, and innervation of the ahFPL. The ahFPL was observed in 29/90 (32%) of the fetus forearms and 20/52 (39%) of the adult cadaver forearms. The overall side incidence was 34.5% (49/142) among total forearms examined. On the other hand, the population incidence of ahFPL was 42% (19/45) in fetuses while it was 50% (12/24) in adult cadavers. So, the overall incidence in humans was 44.9% (31/69) in the population studied. Compression of the AIN in the forearm by the ahFPL is known as one of the causes of the anterior interosseous nerve syndrome (AINS). So, the relation of ahFPL with the AIN was evaluated, and in light of previous classifications a modified new classification is proposed. The most common relation detected in this study was Type IVa (71.4%) (AIN and its branches coursed posterior to the ahFPL). While Type I was not observed in this study, the incidences of Type II, Type III, and Type IVb (all AIN branches ‘without AIN itself’ coursed posterior to the ahFPL) were 2%, 14.3%, and 12.3%, respectively. The Types I, IVa, and IVb are thought to be associated with complete or incomplete types of AINS and Type III with incomplete type of AINS only. Clin. Anat. 25:601–608, 2012. © 2011 Wiley Periodicals, Inc.

[1]  L. Prabhu,et al.  The accessory heads of flexor pollicis longus and flexor digitorum profundus: Incidence and morphology , 2008, Clinical anatomy.

[2]  M. A. El Domiaty,et al.  The prevalence of accessory heads of the flexor pollicis longus and the flexor digitorum profundus muscles in Egyptians and their relations to median and anterior interosseous nerves. , 2008, Folia morphologica.

[3]  V. Gorantla,et al.  Accessory Head of Flexor Pollicis Longus Muscle and its Significance in Anterior Interosseous Nerve Syndrome: Case Report and Review , 2007 .

[4]  G. Kayalioglu,et al.  Incidence and morphology of the accessory head of the flexor pollicis longus muscle (Gantzer`s muscle) in a Turkish population. , 2006, Neurosciences.

[5]  A. Uz,et al.  Possible anatomic structures causing entrapment neuropathies of the median nerve: an anatomic study. , 2005, Acta orthopaedica Belgica.

[6]  Michael J Lee,et al.  Pronator syndrome and other nerve compressions that mimic carpal tunnel syndrome. , 2004, The Journal of orthopaedic and sports physical therapy.

[7]  L. de Smet,et al.  Anterior interosseous nerve paralysis due to Gantzer's muscle. , 2004, Acta orthopaedica Belgica.

[8]  W. Schady,et al.  Favourable outcome in non-traumatic anterior interosseous nerve lesions , 1993, Journal of Neurology.

[9]  P. Mahakkanukrauh,et al.  Prevalence of accessory head of flexor pollicis longus muscle and its relation to anterior interosseous nerve in Thai population , 2004, Clinical anatomy.

[10]  Oguzhan Ozdemir,et al.  ANTERİOR İNTEROSSÖZ SİNİR SENDROMU :OLGU SUNUMU , 2002 .

[11]  G. Rayan,et al.  Anterior interosseous nerve syndrome: a case report. , 2002, The Journal of the Oklahoma State Medical Association.

[12]  A. Asselineau,et al.  Compression du nerf interosseux antérieur par le muscle de Gantzer , 2001 .

[13]  Jerry Tchoryk.  Median and anterior interosseous nerve entrapment syndromes versus carpal tunnel syndrome: a study of two cases , 2000 .

[14]  I. Chung,et al.  Anatomical study of the accessory head of the flexor pollicis longus and the anterior interosseous nerve in Asians , 2000, Clinical anatomy.

[15]  S. Shirali,et al.  The Flexor Pollicis Longus and its Relation to the Anterior and Posterior Interosseous Nerves , 1998, Journal of hand surgery.

[16]  오창석,et al.  한국사람 긴엄지굽힘근 덧갈래(Accessory head of Flexor Pollicis Longus) , 1998 .

[17]  M. Jones,et al.  Incidence and morphology of accessory heads of flexor pollicis longus and flexor digitorum profundus (Gantzer's muscles) , 1997, Journal of anatomy.

[18]  M. Al-Qattan.  Gantzer’s Muscle , 1996, Journal of hand surgery.

[19]  P. Haussmann,et al.  Intraepineurial constriction of nerve fascicles in pronator syndrome and anterior interosseous nerve syndrome. , 1996, The Orthopedic clinics of North America.

[20]  P. Seror.  Anterior interosseous nerve lesions. Clinical and electrophysiological features. , 1996, The Journal of bone and joint surgery. British volume.

[21]  A. Subramanya,et al.  Occasional head of flexor pollicis longus muscle: a study of its morphology and clinical significance. , 1993, Journal of postgraduate medicine.

[22]  W. Eversmann.  Proximal median nerve compression. , 1992, Hand clinics.

[23]  S. Mackinnon,et al.  Musculoaponeurotic Variations along the Course of the Median Nerve in the Proximal Forearm , 1987, Journal of hand surgery.

[24]  N. P. Sing,et al.  The accessory head of the flexor pollicis longus muscle and its nerve supply. , 1982, Anatomischer Anzeiger.

[25]  U. Mangini.  Flexor pollicis lungus muscle. Its morphology and clinical significance. , 1960, The Journal of bone and joint surgery. American volume.

[26]  W. S. Monkhouse,et al.  GRAY'S ANATOMY , 1947 .

[27]  J. Dykes,et al.  The accessory tendon of the flexor pollicis longus muscle , 1944 .

[28]  J. Judd.  Always strong and happy : a complete system of treatment for the general care of the body, with full directions for the development of the muscular system -- , 1895 .