Prevalence of accessory head of flexor pollicis longus muscle and its relation to anterior interosseous nerve in Thai population.
ABSTRACT A detailed description of the accessory head of flexor pollicis longus muscle (AHFPL) in the Thai population has not been reported. Because it is one of the causes of anterior interosseous nerve syndrome (AINS), a study was carried out on 120 Thai cadavers (70 embalmed, 50 fresh; 78 male, 42 female) to elucidate the prevalence of AHFPL, its morphology and relationship with the anterior interosseous nerve (AIN). The prevalence of AHFPL was 62.1% (149/240) with 74.5% (111/149) of its origin on medial epicondyle, 23.5% (35/149) on coronoid process and 2% (3/149) on flexor digitorum superficialis muscle. One hundred percent of its insertion was on the ulnar border of flexor pollicis longus tendon, and it was 98% (146/149) fusiform-shaped and 2% (3/149) slender shaped, with a diameter between 0.8-16.0 mm (average 6.7 mm), averaging 6.5 mm on the right and 4.2 mm on the left. The right was significantly statistically larger than the left (P < 0.05). The average distance from the mid-point of the distal wrist crease to the insertion point of AHFPL was 12.8 cm. Four patterns of relationship with AIN were noted including: 1) I AIN passed anterior to AHFPL, 13.4% (20/149); 2) AIN passed lateral to AHFPL, 65.8% (98/149); 3) AIN passed posterior to AHFPL, 8.1% (12/149); and 4) AIN passed both lateral and posterior to AHFPL, 12.8% (19/149). We believe that the latter two patterns (3 and 4) with AIN passing posteriorly would be more likely to be associated with AINS due to anatomic considerations.
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ABSTRACT: Introduction: The present study was planned to analyze the Accessory Head of the Flexor Pollicis Longus muscle' (AHF-PL) or Gantzer's muscle and its incidence. It is an additional muscle in the forearm which might cause pressure symptoms to the underlying structures, especially to the anterior interos-seus nerve.Journal of Clinical and Diagnostic Research 03/2013; 7(Journal of Clinical and Diagnostic Research. 2013 March, Vol-7(3): 418-421):418-421.
Article: 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.[show abstract] [hide abstract]
ABSTRACT: Entrapment neuropathy in the forearm is not uncommon. Surgical interference for nerve decompression should be preceded by accurate diagnosis of the exact cause and site of the nerve entrapment. The aim of the present study was to investigate the prevalence of accessory heads of the flexor pollicis longus and flexor digitorum profundus muscles (FPLah) and (FDPah) in Egyptians and their topographical relationship with both the median nerve and its anterior interosseous branch. A total of 42 upper limbs of embalmed cadavers, 36 from males and 6 from females, were examined to elucidate the prevalence of both the FPLah and the FDPah muscles, their origin, insertion, nerve supply and morphology. The distribution of these two muscles in the right and left male and female upper limbs and their relationship to the anterior interosseous and median nerves were recorded. The total lengths of both accessory muscles and the lengths of their fleshy bellies and tendons were also measured. The FPLah was found to be present more frequently (61.9%) than it was absent, whereas the FDPah was observed in only 14.24% of the specimens examined. The combination of the accessory muscles in the same forearm was noticed in 9.52% of cases. As regards side, the FPLah appeared in 77.7% of the right forearms and in 50% of the left, while the FDPah was found in only 25% of the left forearms. The accessory muscles showed no single morphology, as the FPLah appeared fusiform in 53.8%, slender in 30.8% and voluminous fusiform in 15.4%, while the FDPah was slender in 66.6% and triangular in 33.3% of specimens. The FPLah arose mainly from the under surface of flexor digitorum superficialis, while the FDPah took its origin from the under surface of flexor digitorum superficialis or from the medial epicondyle. The insertion of the FPLah was mainly into the upper third of the FPL tendon, while the FDPah tendon joined the tendons of the flexor digitorum profundus muscle to the index or middle and ring fingers. The FPLah was found between the median nerve anteriorly and the anterior interosseous nerve posteriorly. Both FPLah and FDPah took their nerve supply mainly from the anterior interosseous nerve and, less frequently, from the median nerve. The mean values of the total lengths of FPLah and FDPah were 74.66 mm and 208.33 mm, respectively. Cadaveric dissection in this study confirmed the prevalence of the FPLah and FDPah in Egyptians and demonstrated the relationship of the FPLah to the median nerve and its anterior interosseous branch. These findings may provide the surgeon with information for the differential diagnosis of the causes and sites of anterior interosseous nerve syndrome and entrapment neuropathy of the median nerve in the forearmFolia morphologica 03/2008; 67(1):63-71. · 0.52 Impact Factor