Anatomic feasibility study of osteocutaneous free flap from the proximal ulna

The present anatomic study aimed to assess the feasibility of an osteocutaneous free flap harvested from the proximal ulna for reconstruction after complex hand trauma.

Nineteen upper limb specimens free of scarring in the elbow region were injected in the brachial artery. After S-shaped incision centered on the medial epicondyle, a systematic approach to the epitrochlear-olecranal groove exposed the superior ulnar collateral artery and ulnar nerve. Bone and skin perforators were screened for during dissection and their emergence with respect to the medial epicondyle was assessed. Pedicle length was also assessed. The skin paddle was harvested in the distal part of the S incision and the operative site was closed by local skin plasticity.

Bone and skin perforators from the superior ulnar collateral artery were found in all 19 specimens. Mean pedicle length from the artery was greater than 9cm in all cases. The skin perforator emerged at a mean 19mm distally from the medial epicondyle, and the bone perforator at a mean 40mm.

An osteocutaneous free flap can be harvested from the proximal ulna and medial side of the elbow. As bone and skin perforators were found in all 19 cases, this flap can be used routinely. Harvesting, however, systematically involves ulnar nerve release and anterior transposition. This osteocutaneous free flap harvested from the proximal ulna offers an alternative for osteocutaneous defects in the hand, with harvesting from the same limb.

In this anatomic series, an osteocutaneous free flap could in all cases be harvested from the posterior ulnar recurrent artery via a medial elbow approach. Safety and efficacy remain to be demonstrated in in vivo reconstruction.

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