Functional pectoralis minor myocutaneous flap transplantation for reconstruction of thumb opposition: An anatomic study with clinical applications

Summary: Objective: To develop a myocutaneous flap for reconstruction of thumb opposition function in patients with loss of the thenar muscles and skin. Methods: An anatomic experiment on the dimensions of the pectoralis minor muscle and its neurovascular supply in 10 adult human cadavers was conducted to evaluate the feasibility of microsurgical transplantation using part of the muscle for thumb opposition reconstruction. Based on these results, we performed surgical thenar reconstruction with a pectoralis minor myocutaneous flap in seven patients (34.7 ± 9.8 years of age) from December 2007 to October 2010. Results: The transferred muscle was reinnervated with the third lumbrical branch of the ulnar nerve. Six to twelve months after the surgery, follow-up assessment showed that all patients had recovered functional opposition of the carpometacarpal joint with survival of the skin and a muscle power of M4 to M5. Conclusion: Our results support the use of this new technique for thenar and opposition reconstruction in patients with severe loss of the thenar muscles and skin and damage to the median nerve and who wish to improve the appearance of the thenar eminence. Keywords: Anatomy, Clinical applications, Myocutaneous flap, Pectoralis minor muscle, Thumb oppositio