Treatment of Complex Hand Injuries Using the Dorsal Ulnar Artery Perforator Flap

Introduction: Functional disorders due to tendon adhesion and scar tissue around nerves arise as complications after the initial treatment of incomplete amputation and severe crush injury of the forearm and wrist lacerations, by vascular reconstruction, etc. We recently have used dorsal ulnar artery perforator flaps (DUAPF) to cover the tendons and nerves during initial treatment as well as to repair soft tissue defects after elimination of cicatrices during secondary tenolysis and neurolysis in cases of complex hand injuries. The flap was first reported by Becker and Gilbert et al. and uses the dorsal ulnar artery as the pedicle.

Methodology and Material: Fifteen patients of complex hand injuries were studied. The injury was caused by an electric saw in five patient, a press in eight patients, and so-called “spaghetti wrist” by self-laceration in two. The patients ranged in age from 16 to 47 years old (mean: 30 years). The DUAPF was used during the initial surgery in 6 patients and during secondary tenolysis or neurolysis in 9.

The DUAF was prepared as follows. First, a small skin incision, ∼2 cm long, was made over the ulnar axis 2 cm proximal to the pisiform bone, and the flexor carpi ulnaris muscle was pulled with a retractor. The posterior ulnar artery, which serves as the vascular pedicle, was then identified. The vascular pedicle usually divides into three branches within the flexor carpi ulnaris muscle, and one of them is an ascending branch running proximally. After identifying this branch, the ultimate design of the flap was determined.

The flap was rotated once and was placed over the site of the soft tissue defect and cicatrix elimination around the hand joint, while covering the tendon and the nerves. In five patient, a vein in the flap was anastomosed with the cutaneous vein on the recipient side.

Results: The vascular pedicle could be identified in all cases. The postoperative results assessed according to Chen’s classification were Grade 3 in five patients, Grade 3 in four patients, and Grade 1 in six patients. A DUAPF was used as the pedicle flap in all cases, and as the fascial flap in three of them. Strong adhesion of the flap to the underlying tissues was not observed postoperatively, and none of the patients required re-detachment of the tendon and nerves.

Conclusions: Treatment of complex injuries becomes difficult if hard scar occurs at the site of the injury on the palmar side and the tendons or nerves adhere to the skin. It therefore seems best to use a flap with good circulation to cover the site in the early stage whenever possible. However, it is not always possible to obtain a free flap, and free skin grafts are associated with the risk of adhesion. This technique, which uses a pedicle flap that can be obtained from the same surgical field without sacrificing the main artery, is believed to be very useful.