The use of chimeric musculocutaneous posterior interosseous artery flaps for treatment of osteomyelitis and soft tissue defect in hand.

INTRODUCTION: There is growing evidence of the superior ability of muscular tissue to clear bacterial bone infection. Unfortunately, in the hand, there are almost no small local muscular flaps, and muscular transfers to the hand are mainly microsurgical free transfers. In this report, we present the results of the use of a chimeric posterior interosseous flap including part(s) of the forearm muscles to treat osteomyelitis and soft tissue defect of hand from a series of patients.

PATIENTS AND METHODS: Four male patients with an average age of 32 years (range 20-46 years), were affected by acute osteomyelitis in hand. Previous fracture fixation with percutaneous K-wires was the cause of bone infection in three case. In one case, the osteomyelitis was a consequence of an open fracture. The bones affected were four metacarpals and one proximal phalanx, all with a minimal cortical defect (from the K-wire) obscuring a larger medullary infection, which required extensive bone and overlying soft tissue debridement, leaving a soft tissue defect to be reconstructed of size ranging from 2 x 4 cm to 5 x 7 cm. The soft tissue defects were due to concomitant superficial infection and consequent debridement. All patients were treated with bone debridement and a chimeric posterior interosseous flap, which included part of the extensor digiti minimi and/or extensor carpi ulnaris to fill the intramedullary canal of the bones. No fixation of bone was necessary.

RESULTS: The skin paddle of the flaps ranged from 2 x 5 cm to 5 x 6 cm, replicating the defect area, plus a teardrop tail of skin circa 1.5 cm wide and as long as the pedicle of the flap. The muscular components of the flaps used to fill the intramedullary canals ranged from 1 x 1 x 1.5 cm to 1.5 x 1.5 x 4 cm. All flaps survived and osteomyelitis resolved in all cases without major complications. At the final follow-up at 16 months (range 12-26 months), assessment of the hands using TAM, Power Grip and Key Pinch Strength measurements and, where appropriate, Kapandji scores, demonstrated satisfactory hand function.

CONCLUSION: The chimeric posterior interosseous flap including part of the muscles of the forearm may be a robust solution for augmenting the flap bulk and may be used in cases of severe osteomyelitis of the hand.