Neurovascular details about forearm muscles: applications in their clinical use in functional muscular transfer

The concept of muscle subunits has been introduced for limb reconstruction and functional conservation of donor site, yet it requires thorough understanding of neurovascular anatomy of muscles. The present study provides neurovascular details of forearm skeletal muscles. Twenty-eight forearms were dissected totally, ten for observing extramuscular nerve distribution, ten for observing intramuscular nerve distribution by modified Sihler's technique, and the other eight for observing intramuscular artery distribution by aqueous barium sulfate infusion. The forearm muscles were classified into three different types according to Lym's classification. Numbers of extramuscular and intramuscular nerves were counted and compared between the types. Intramuscular vascular distribution was also classified into three different types according to Mathes' method. Intramuscular vascular distribution was compared with nerve distribution as well. There were also some variations in the composition of muscular branches. Numbers of intramuscular nerve branches were significantly higher in muscle types IIa and III. Morphology and intramuscular neurovascular distribution of type II muscles are easy to split into two independent parts for functional muscular flap transfer according to morphology and intramuscular neurovascular distribution. The present study elucidated that flexor carpi ulnaris and radialis, extensor carpi ulnaris, and carpi radialis brevis were suitable for functional muscular transfer from several different insights, but the roles of pronator teres and supinator remained to be controversial. This study might be very helpful to plastic surgeons and anatomists.