Preexpanded Muscle-Sparing Latissimus Dorsi Free Flap in Complex Lower Limb Trauma: The Orthoplastic Approach

Abstract

Sir: Reconstruction of large defects of the knee may require free flaps with a large surface area of pliable skin along with a long pedicle. Flaps that have been described to cover such defects include free latissimus dorsi and free expanded latissimus dorsi flaps; however, these can be too bulky and may leave large defects on the back. We present the case of a 15-year-old boy who was involved in a road traffic collision 4 years previously, in which he sustained a degloving injury to the posterior knee complicated by an open femoral fracture. Initial treatment involved stabilization of the fracture, bony cover with local tissue, and split skin graft for reconstruction of the skin defect. Subsequently, there was growth arrest caused by significant injury to the growth plate, compounded by severe soft-tissue contracture resulting in a fixed flexion deformity of the left knee (Fig. 1).Fig. 1.: Preoperative flexion contracture and tissue expander in situ (digitally acquired leg length images).According to the joint British Association of Plastic, Reconstructive, and Aesthetic Surgery and the British Orthopaedic Association guidelines, the patient was assessed by the multidisciplinary lower limb trauma and reconstruction team. It was immediately apparent that tissue coverage of the deformity would require a sizable skin paddle of approximately 36 × 20 cm. Given the patient's clinical needs and the lack of a suitable immediate donor site, the decision was made to expand a large fasciocutaneous skin flap on the patient's back. During the first stage, a customized three-chambered tissue expander was placed in the subfascial plane in the back, and a Doppler device was used to identify and therefore avoid the perforator to the left latissimus dorsi. Over a 3-month period, expansion of 2440 ml was achieved, creating a sizable soft-tissue paddle. At definitive surgery, the flexion deformity was corrected with femoral valgus and derotational osteotomy, along with application of a rail fixator for femoral lengthening by distraction. The area of split skin graft covering the popliteal fossa was excised. This allowed correction of a significant component of the flexion deformity. This large-sized soft-tissue defect (36 × 20 cm) was covered with the preexpanded muscle-sparing latissimus dorsi free flap, incorporating much of the expanded skin but still leaving enough to allow primary closure of the secondary defect. Three months postoperatively, the patient had good range of movement at the knee, with no flap or donor-site complications (Fig. 2).Fig. 2.: Postoperative flap and femoral distractor (left), and the donor site (right).Complex and large soft-tissue defects of the knee require coverage with a large flap. Both free latissimus dorsi and expanded latissimus dorsi flaps have been described to cover such defects.1,2 The muscle-sparing latissimus dorsi flap has been described mainly in breast reconstruction.3–5 The advantages of this flap are reduced seroma rates and lack of functional morbidity, without cosmetic sequelae.4,5 To our knowledge, this is the first report of this flap being used for this purpose. We believe that preexpanded muscle-sparing latissimus dorsi free flap reconstruction has a role in large, complex, lower limb trauma cases. It provides large amounts of skin with minimum donor-site morbidity and shows the versatility of the muscle-sparing latissimus dorsi flap beyond the realms of breast reconstruction. DISCLOSURE No funding was received to support this work. The authors have no commercial associations or financial interest to declare. Nathan T. J. Hamnett, M.R.C.S. Anuj Mishra, M.R.C.S. Selvadurai Nayagam, M.Ch.(Orth.), F.R.C.S.(Plast.) Ken Graham, F.R.C.S.(Plast.) Christian Duncan, F.R.C.S.(Plast.) Department of Plastic Surgery Alder Hey Children's NHS Foundation Trust Liverpool, England