Abstract
There are many reports of the use of free fibular flap for mandible reconstruction, but donor site morbidity is not uncommon. The authors present the case of a 52-year-old man who underwent mandible reconstruction with free fibular flap. After surgery, he developed severe compartment syndrome involving all four-calf compartments. Debridement of the necrotic areas was followed by posterior nerve neurolysis and soft tissue coverage with free latissimus dorsi and anterior serratus muscle flaps. The postoperative period was uneventful and the patient remained with diminished plantar sensation 1 year later. Compartment syndrome after fibula harvesting is a possibility and should be recognized as soon as possible in order to limit extensive damage to the calf muscles and nerves.
The first application of a fibular flap for mandible reconstruction was reported by H idalgo in 1989. Since then, there have been many reports of its successful application. The fibular bone has a bicortical structure that allows easy internal fixation and later reconstruction with endosseous implants. Several osteotomies can be applied to adapt the bone segments to the mandibular shape. The fibular bone has a single vascular pedicle with large diameter vessels and significant blood flow.
The calf has four compartments. The anterior compartment located anterior to the interosseous membrane has four muscles (from medial to lateral): tibialis anterior, extensor digitorum longus, extensor hallucis longus and peroneus tertius. The deep peroneal nerve is one of the two branches of the common peroneal nerve and accompanies the anterior tibial artery; it innervates these extensor muscles. The anterior tibial artery descends on the interosseous membrane and between the tibialis anterior and extensor digitorum longus. The lateral compartment is bounded by the lateral surface of the fibula, anterior and posterior septa and the crural fascia. It contains the peroneus longus and brevis muscles. The superficial peroneal nerve is the other terminal branch of the common peroneal nerve. It supplies the skin on the dorsal part of the leg and dorsum of the foot. This compartment does not have an artery. The posterior calf has two compartments separated by the transverse intermuscular septum. The superficial posterior compartment contains the gastrocnemius, soleus and plantaris muscles. The deep posterior compartment contains the popliteus, flexor digitorum longus, flexor hallucis longus and tibialis posterior muscles. The tibial nerve supplies all the muscles in the posterior compartment. The posterior tibial artery and the peroneal artery supply the posterior compartment muscles. The peroneal artery also supplies the lateral compartment of the calf.
Numerous causes of compartment syndrome are reported . It may be the result of externally applied compressive forces or internally expanding structures. Any fractures, vascular injuries, prolonged compression, deep venous thrombosis, overexertion, fluid sequestration, prolonged surgery or small trauma can lead to lower limb compartment syndrome. Generally, the success of free tissue transfer exceeds 95%, but there are reports of donor site complications. The authors report a case of severe compartment syndrome that involved all four compartments and required debridement and free latissimus and serratus muscle flaps for defect coverage.
Case report
A 52-year-old man, a heavy smoker with a T 4 N 2c M o squamous cell carcinoma of the floor of the mouth invading the mandible, was admitted to a maxillofacial department. The patient underwent partial mandibulectomy and bilateral modified radical neck dissection. The bony and soft tissue defect was reconstructed immediately with an osteocutaneous free fibular flap. Ultrasound Doppler of the calf was performed before fibula harvesting. Under the tourniquet, through a standard lateral approach, the flap was harvested from the right calf. The skin paddle was 10 cm × 5 cm and the bone was segmented into three parts for mandible contour. 8 cm of distal fibula and 6 cm of proximal fibula were maintained. The tourniquet was applied for 73 min. Modelling of the fibula was carried out after deflating the tourniquet. The remaining fascia in the donor calf was approximated with sutures and the defect was covered by a split thickness skin graft. The patient was postoperatively treated with major analgesics.
On the third postoperative day, the patient complained of pain in the lower leg that was interpreted as normal donor area pain. Over the next 2 days, the local pain increased despite major analgesics and the patient was referred ( Fig. 1 ). The patient reported severe pain on passive flexor and extensor tendon movement. Plantar anesthesia was present. A clinical diagnosis of compartment syndrome was made and the patient was taken to the operating theatre. The intracompartmental pressure was not measured since the clinical diagnosis was highly suggestive of compartment syndrome. Approximately 80% muscle necrosis was present in all four compartments ( Fig. 2 ). Debridement of necrotic areas was followed by posterior nerve neurolysis. The nerve was found to be surrounded and compressed by the inflammatory tissue. The soft tissue defect and dead space was covered with a free flap. Latissimus dorsi and anterior serratus muscles were harvested on the subscapular vessels. The free flap was inset with the serratus muscle placed in the deep part of the distal calf ( Fig. 3 ). The artery was sutured end-to-side to the proximal posterior tibial artery and the vein was sutured end-to-end to the comitant vein. Part of the muscle was covered with a split thickness skin graft. The postoperative course was uneventful, and the fibular flap was successful for mandible reconstruction. No complaints were noted at the 1 year follow-up ( Fig. 4 ), although the plantar area remained with diminished sensation.
