**6. Fibula flap**

The fibula bone is most commonly used in oral and maxillofacial reconstruction following benign or malignant jaw tumor ablation Hidalgo, in 1989, reported the first mandibular reconstruction using a vascularized fibula free flap. [27]. It has several advantages over other bones, including being the longest bone with lengths up to 25 cm, having bicortical structures that can support osseointegrated dental implants, having a large caliber and long vascular pedicles which provide easier anastomosis, and having thin and pliable skin paddles as well as available muscular cuffs around the fibula which can be used for reconstructing the various soft tissue defects (Figures 5 and 6). The morbidity at the donor site is also low and the operation time is reduced because of a two-team approach.

**Figure 5.** A composite fibula flap used to restore the hemimandible and the oral floor.

**Figure 6.** A composite fibula flap for reconstruction of the hemimandible and soft tissue defect on the face.

#### **6.1. Flap anatomy**

cover the donor site after radial forearm flaps. Results demonstrated thicker coverage of the

The fibula bone is most commonly used in oral and maxillofacial reconstruction following benign or malignant jaw tumor ablation Hidalgo, in 1989, reported the first mandibular reconstruction using a vascularized fibula free flap. [27]. It has several advantages over other bones, including being the longest bone with lengths up to 25 cm, having bicortical structures that can support osseointegrated dental implants, having a large caliber and long vascular pedicles which provide easier anastomosis, and having thin and pliable skin paddles as well as available muscular cuffs around the fibula which can be used for reconstructing the various soft tissue defects (Figures 5 and 6). The morbidity at the donor site is also low and the operation

forearm defect, with minimal donor site morbidity and superior cosmetic results. [26]

**6. Fibula flap**

time is reduced because of a two-team approach.

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**Figure 5.** A composite fibula flap used to restore the hemimandible and the oral floor.

The arterial supply of the fibula flap is the peroneal artery. The peroneal artery branches from the posterior tibial artery just proximal to the head of the fibula. The external diameter of the peroneal artery is 1.5-2.5 mm. The pedicle length varies and may be quite long if a large segment of the proximal part of the bone is resected. The skin over the lateral leg is also nourished by the peroneal artery via septocutaneous vessels that course posterior to the fibula to enter the posterior crural intermuscular septum. [19] Venous drainage of the flap is primarily by venae comitante (two) of the peroneal artery. The venae comitante often merge to form a single large vein near the posterior tibial artery. Sensory innervation to the corresponding lateral leg skin is mostly supplied by the lateral sural nerve. It can be detected under micro‐ scopic view. It is possible to enclose the lateral sural nerve with the fibula flap to improve function of recipient site (Figure 7). [28]

**Figure 7.** Anatomy of a free fibula flap

#### **6.2. Flap component**

The fibula flap is harvested as a bone flap and may consist of muscles (soleus or flexor hallucis longus), overlying fascia and/or skin (Figure 8). [28]

**Figure 8.** Components of a fibula flap

### **6.3. Flap dimensions**

**Figure 7.** Anatomy of a free fibula flap

**Figure 8.** Components of a fibula flap

longus), overlying fascia and/or skin (Figure 8). [28]

630 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

The fibula flap is harvested as a bone flap and may consist of muscles (soleus or flexor hallucis

**6.2. Flap component**

The skin paddle length can be 12 cm and its width can be 6 cm. The bony part length is 16 cm (range 6-26 cm) and its thickness 2 cm.

#### **6.4. A common fibula flap harvesting technique**

A tourniquet is placed on the thigh and the knee is partially flexed for access to the postero‐ lateral leg. Firstly, the fibula bone outline and a skin paddle (if it is included in the flap) are marked on the skin. Then an incision is made on the anterior outline. Dissection proceeds anterior to the posterior intramuscular septum, through which fasciocutaneous perforators run. The common peroneal nerve which runs below the level of the head of the fibula is identified and preserved with the peroneal muscles of the anterior surface of the fibula, reflecting the peroneus longus and brevis muscles. The anterior intermuscular septum is incised to gain access to the anterior part. Dissection is extended through the extensor digitorum and extensor hallucis longus. After access to the fibula bone, the maximum length of the bone is included with proximal osteotomy 6 cm inferior to the fibular head and distal osteotomy 8 cm superior to the lateral malleolus (Figure 9).[28] is incised to gain access to the anterior part. Dissection is extended through the extensor digitorum and extensor hallucis longus. After access to the fibula bone, the maximum length of the bone is included with proximal osteotomy 6 cm inferior to the fibular head and distal

osteotomy 8 cm superior to the lateral malleolus (**Figure 10**).[28]

**Figure 10 A: The outline of a fibula flap with a skin paddle Figure 9.** (a): The outline of a fibula flap with a skin paddle. (b): A fibula flap harvest. Note its vascular pedicle.

**Figure 10 B: A fibula flap harvest. Note its vascular pedicle.**

14

#### **6.5. Complications**

The most feared potential donor site complication in fibula flap transfer is foot ischemia secondary to the sacrifice of the peroneal artery. In the most common situation, terminal branches of the peroneal artery arise at the level of the ankle, and the blood supply to the foot is provided by the anterior and posterior tibia arteries. In patients with atherosclerosis of the anterior or posterior tibial vessels, collaterals from the peroneal artery may provide a signifi‐ cant contribution to pedal circulation. The majority of patients with peripheral vascular disease of the lower extremities are easily identified on the basis of history and physical examination. However, there is another group of patients with congenital vascular anomalies for whom the peroneal artery provides a significant contribution to the foot circulation. This subpopulation of patients present a unique difficulty when performing a preoperative evaluation in antici‐ pation of performing a fibula free flap, because they may have a normal history and physical examination.[29] In general, the patient perception of donor-site morbidity is low. Complaints however, were frequently mentioned, including pain (60 percent), dysesthesia (50 percent), a feeling of ankle instability (30 percent), and inability to run (20 percent). Gait analyses revealed that patients walked at a lower preferred velocity, compared with control subjects. Further‐ more, it was demonstrated that significant increases in the coefficients of variation of stride time during walking under visual and cognitive loads and during walking at a velocity higher than the preferred compared with normal walking.[30] Noticeable limitation and discomfort in ankle function and range of motion with aggressive physical activity may result after fibula harvest, particularly if tibiofibular fusion is performed.[28] Commonly the bone flap may tolerate venous thrombosis for up to 24 hours because of spontaneous bleeding from the medullary canal before the artery undergoes thrombosis, but venous drainage of the skin paddle must be managed by reoperation.[28]

#### **6.6. Fibula flap updates**

Proximal peroneal perforator in the dual-skin paddle configuration of fibula free flap has been used to reconstruct composite oral defects. The proximal peroneal perforator was found to be anatomically reliable and clinically useful in composite oral cavity reconstruction. [31] The free fibula flap has been reported to be an appropriate option for mandibular reconstruction in bisphosphonate-related osteonecrosis of the jaws. [32] The keys for gaining maximum success in a fibula flap include:


**6.5. Complications**

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paddle must be managed by reoperation.[28]

**1.** Harvesting the distal fibula when recipient vessels are distant

**5.** Preventing venous thrombosis which is essential to reduce flap complications

**6.** Aligning fibular struts and protecting the vascular pedicle when the double-barrel

**2.** Flap selection based on the anatomy of perforators

**4.** Protection of the flap's soft-tissue cuff

**3.** Use of the skin paddle for postoperative flap monitoring

**6.6. Fibula flap updates**

in a fibula flap include:

technique is used

The most feared potential donor site complication in fibula flap transfer is foot ischemia secondary to the sacrifice of the peroneal artery. In the most common situation, terminal branches of the peroneal artery arise at the level of the ankle, and the blood supply to the foot is provided by the anterior and posterior tibia arteries. In patients with atherosclerosis of the anterior or posterior tibial vessels, collaterals from the peroneal artery may provide a signifi‐ cant contribution to pedal circulation. The majority of patients with peripheral vascular disease of the lower extremities are easily identified on the basis of history and physical examination. However, there is another group of patients with congenital vascular anomalies for whom the peroneal artery provides a significant contribution to the foot circulation. This subpopulation of patients present a unique difficulty when performing a preoperative evaluation in antici‐ pation of performing a fibula free flap, because they may have a normal history and physical examination.[29] In general, the patient perception of donor-site morbidity is low. Complaints however, were frequently mentioned, including pain (60 percent), dysesthesia (50 percent), a feeling of ankle instability (30 percent), and inability to run (20 percent). Gait analyses revealed that patients walked at a lower preferred velocity, compared with control subjects. Further‐ more, it was demonstrated that significant increases in the coefficients of variation of stride time during walking under visual and cognitive loads and during walking at a velocity higher than the preferred compared with normal walking.[30] Noticeable limitation and discomfort in ankle function and range of motion with aggressive physical activity may result after fibula harvest, particularly if tibiofibular fusion is performed.[28] Commonly the bone flap may tolerate venous thrombosis for up to 24 hours because of spontaneous bleeding from the medullary canal before the artery undergoes thrombosis, but venous drainage of the skin

Proximal peroneal perforator in the dual-skin paddle configuration of fibula free flap has been used to reconstruct composite oral defects. The proximal peroneal perforator was found to be anatomically reliable and clinically useful in composite oral cavity reconstruction. [31] The free fibula flap has been reported to be an appropriate option for mandibular reconstruction in bisphosphonate-related osteonecrosis of the jaws. [32] The keys for gaining maximum success **9.** Mastering the learning curve and clinical competence in microvascular reconstruction. [33]

It has been shown that function can reliably be reestablished after segmental mandibulectomy and condylectomy reconstructed with a vascularized fibula flap whose distal end is not precisely contoured or actively seated in the glenoid fossa, as a valid alternative to condylar reconstruction. [34] Skin paddle harvesting is a factor that influences the operation time and patient satisfaction of fibula free flap surgery. An increase in body mass index is related to an increase in donor-site morbidity after fibula free flap transfer. [27]
