Continuing Education Activity

Fibular grafts are employed for a number of different indications, including mandibular defects, leg length discrepancy, pseudarthrosis, and others. These grafts may be harvested through either posterolateral or lateral approaches that preserve the distal end of the fibula to support the ankle joint. This activity reviews the preoperative evaluation and technical aspects of fibular grafting and highlights the role of the interprofessional team in caring for patients who require this procedure.

Objectives:

• Identify the indications for fibula tissue transfer.
• Summarize the treatment considerations for patients with bony defects.
• Review the preoperative vascular status assessment in a patient who is scheduled to undergo free fibular transfer.
• Outline the possible complications of fibular tissue transfer.

Introduction

Autologous grafts have been fundamental to reconstruct bony defects for more than a century; the first description of free fibular graft transfer, however, was reported by Taylor et al. in 1975.[1][2] More recently, the lateral approach to fibula harvest was popularized by Gilbert, followed by Chuang et al., who described free, vascularized fibula transfer with a skin paddle and functional soleus muscle for forearm reconstruction.[3][4]

Numerous options exist to reconstruct bony defects, including nonvascularized cancellous and cortical autografts, cadaveric bone allografts, endoprosthesis placement, bone transfer procedures, and vascularized bone grafts as well, such as iliac crest, rib, scapula, and fibula.[5][6] Free vascularized fibular grafting is widely utilized for reconstructing skeletal defects larger than 6 cm due to the fibula's length, straightness, strength, predictable vascular pedicle, and hypertrophy potential that can enhance long-term bone remodeling.[7]

Nowadays, a fibular transfer is commonly utilized after tumor surgery, pseudarthrosis rescue, mandibular defect reconstruction, and chronic osteomyelitis management. A vascularized epiphyseal transfer is used for reconstruction in skeletally immature patients with complex injuries in order to preserve the potential for ongoing longitudinal growth and provide a viable articular surface for effective joint function.[8]

Anatomy and Physiology

The fibula is a long bone situated in the lateral aspect of the distal lower extremity; it is closely articulated to the tibia via the interosseous membrane as well as proximal and distal tibiofibular joints. The proximal tibiofibular joint is synovial in nature and reduces torsional stress in the lower extremity; the distal tibiofibular joint is considered syndesmotic and possesses very limited mobility.[9][10]

The fibula is composed of three parts:

• Head
• Neck
• Shaft
• Distal end of the fibula

The fibula has three surfaces:

• Lateral
• Medial
• Posterior

The shape of the fibular shaft is determined by the muscle attachments. The distal end of the fibula comprises the lateral malleolus, which articulates with the lateral talus, creating part of the ankle. Mean fibula length is 387.4 ± 23.7 mm in male patients and 361.5 ± 12.3 mm in female patients; close to 30 centimeters can often be harvested.

Ossification of the fibula takes place in three areas, in the center and at the epiphyses at either end. The process of ossification ends in the second decade of life. The common peroneal nerve courses around the neck of the fibula, and this is clinically relevant because the nerve may be injured in fractures of the neck of the fibula.

Understanding the blood supply of the fibula is critical when planning the transfer of vascularized fibula flaps. Long bones generally possess three separate blood supplies: endosteal nutrient vessels, penetrating periosteal vessels typical of the metaphysis and epiphysis, and nonpenetrating periosteal vessels typical of the diaphysis.[11] The fibula's perfusion comes from three major vessels: the anterior tibial, the peroneal, and the posterior tibial arteries. The identity of the dominant artery, which usually supplies the dorsalis pedis artery, must be confirmed prior to any surgical intervention. If the dominant artery is the peroneal artery, then the transfer of a vascularized free fibular flap will be contraindicated, as ischemia of the foot would result postoperatively.[12]

Joints and Supporting Structures

Proximal Tibiofibular Joint

The synovial joint between the head of the fibula and lateral condyle of the tibia is supported by a joint capsule, anterior and posterior superior tibiofibular ligaments, the lateral collateral ligament, and the biceps femoris.

Distal Tibiofibular Joint

The fibrous joint between the fibular notch and distal tibia is supported by an interosseous membrane, anterior and posterior inferior tibiofibular ligaments, and the inferior transverse tibiofibular ligament.

Indications

Fibular tissue grafts/flaps are used in the following scenarios:[13][14][15]

1. Large posttraumatic skeletal defects (>6 cm for either upper or lower limbs)
2. Significant bone stock deficit after tumor resection
3. Pseudarthrosis of the long bones
4. Leg length discrepancy 
5. Mandibular or maxillary defect reconstruction
6. Chronic osteomyelitis (when antimicrobial options fail)
7. Vascularized epiphyseal transfer
8. Cortical bone grafting (osteoconductive and osteoinductive for non-union)
9. Grafting for osteonecrosis of the head of the humerus or femur

Selecting the appropriate surgical technique is a complex decision to be made after a discussion between the interprofessional team and the patient. While a plethora of options are available for the management of various bone defects, there is no formal consensus in the literature regarding which method is consistently most appropriate for a given defect; however, a preponderance of evidence supports the use of fibular grafting is an excellent option in many cases due to its high success rate and low incidence of complications or donor site morbidity.[4][5][7][8][15][16]

Contraindications

Fibular grafting may be contraindicated in the following scenarios, as potential complications may arise after the fibular transfer:

• History of peripheral vascular disease involving the extremity
• History of trauma or surgery in the distal lower extremity
• Hypoplastic anterior tibial artery
• Venous insufficiency (potential for donor site complications)
• Recurrent infection (for non vascularized fibular grafting)

Equipment

The following equipment should be available:

• Skin marker
• Doppler ultrasound probe
• Bard-Parker #3 scalpel handle and #15 blade
• Povidone-iodine or chlorhexidine surgical antiseptic
• Langenbach retractors
• Periosteal elevator
• Plain and toothed forceps, such as Adson-Brown, Gerald, or DeBakey
• Bone saw, such as an oscillating saw or Gigli
• Acland "bulldog" clamps (for vascularized tissue transfer)
• Microvascular instrument set
• Operating microscope
• Heparinized saline
• 2% lidocaine or 3% papaverine
• Microsutures and micro-couplers
• Surgical clips
• Vessel loops
• Plates, screws, and intramedullary rod, if necessary
• Drill and bits for pre-drilling screw holes
• Screwdriver
• Suction drains
• Absorbable and nonabsorbable sutures, such as polyglactin, poliglecaprone, and polypropylene or nylon
• Dressing supplies

Personnel

The following personnel is recommended:

• Anesthetist
• Primary surgeon (a second primary surgeon will permit a simultaneous two-team approach: one for fibula harvest and one for work at the recipient site)
• Surgical assistants
• Operating room assistant
• Staff nurse

Preparation

In the case of planned vascularized fibular transfer, an evaluation of the perfusion of the donor's lower extremity should be performed before the day of surgery. Duplex ultrasonography and computed tomographic angiography are the most common methods of ensuring patency of the peroneal as well as anterior and posterior tibial arteries. In the event of peroneal insufficiency or dominance, a different donor site, such as iliac crest or scapula, should be chosen; if the peroneal artery is insufficient, the flap will not perfuse adequately after the transfer, and if the peroneal artery is dominant over the tibial arteries, the foot may not perfuse after a flap harvest that includes removal of the peroneal artery.

On the day of surgery, an informed consent discussion should occur, in which alternative options to fibular reconstruction should be enumerated, as well as the risks and the anticipated postoperative course. The risks of the operation include flap failure, foot drop, gait disturbance, ankle instability, pain, bleeding, infection, and need for additional surgery in the future.

The procedure is performed under general anesthesia, and antibiotic prophylaxis is administered prior to induction, with repeated doses at appropriate intervals throughout the surgery. The donor and recipient sites are prepared with a surgical antiseptic. An Esmarch bandage may be used to exsanguinate the lower extremity prior to tourniquet placement. The patient is positioned in the supine/lateral decubitus position with a sterile tourniquet on the affected limb set to 150 mmHg above the mean arterial pressure. All pressure points are carefully padded, including the contralateral fibular head (to protect the peroneal nerve), pelvis, heel, and contralateral axilla (to protect the brachial plexus), given that these operations often take 6 to 8 hours or longer to complete. Ideally, the procedure is performed by two surgical teams simultaneously; the first team works at the recipient site while the other addresses the donor site.[16]

Technique or Treatment

The recipient and donor sites can be approached simultaneously by two surgical teams to decrease operative time and related complications.

Recipient Site

Actions at the recipient site depend on the indication for grafting and the nature of the defect. Oncologic resection and lymph node dissection, as well as frozen section clearance, may be required, or work may be limited to simple debridement. Proximally and distally, the periosteum is ideally preserved to aid healing and bony union. The length of the defect should be measured after recipient site work is complete in order to inform the graft harvest team's efforts. If vascularized tissue transfer is planned, the recipient site team will also need to identify and isolate appropriate caliber vessels to support the flap.[17] 

Donor Site

Harvesting of the fibular graft is often performed through the anterolateral approach described by Gilbert.[4] The plane between the peroneus longus and the soleus muscles is developed, and dissection is carried deep to the fibula, protecting the superficial peroneal nerve anteriorly. Bony cuts may be made corresponding to the measured reconstruction length, although some surgeons prefer to harvest the entire fibula, less 5 to 6 cm at the proximal and distal ends, to ensure ankle stability distally and to protect the peroneal nerve proximally. If the maximum length of the fibula is harvested, the bone can be contoured as necessary on the back table prior to flap inset. After carefully dissecting the flexor hallucis longus, the fibula is retracted anteriorly. Towel clamps are applied at the superior and inferior ends of the fibular graft and rotated gently outward. If vascularized bone is required, the peroneal vessels are harvested together with the fibula.[18] In closing the donor site, the flexor hallucis longus is sutured to the interosseous membrane, and the peroneus longus is sutured to the soleus. Skin is closed primarily except in the area of the defect from the cutaneous paddle harvest, which is typically covered with a split-thickness skin graft.[19]

Graft Placement

The graft may be fixated into the defect in an end-to-end fashion if the thickness of the fibular segment and the recipient site roughly match; however, when the defect is broader than the fibula's caliber, a "double-barrel" technique may be appropriate, for example in femoral or tibial defects. In these cases, the fibula is divided, keeping the periosteum intact to the greatest extent possible to preserve blood flow, and then folded upon itself to effectively double its breadth. The graft is otherwise trimmed to fit the recipient site and fixated into the defect as necessary. Fixation is generally accomplished with a small plate and screw constructs, Rush rods, or K-wires. For vascularized fibular graft transfer, arterial anastomosis is performed with 8-0 or 9-0 nylon on a tapered needle, generally under an operating microscope. Incorporating a skin flap, supplied by the peroneal artery, is useful not only for composite reconstruction of bone and soft-tissue defects but also to facilitate postoperative monitoring of the flap's viability. Distal tibiofibular fusion is generally performed as described by Langenskiöld to prevent a postoperative valgus deformity of the ankle.[7]

Postoperative Care

Patients should be given low-molecular-weight heparin for deep venous thrombosis prophylaxis and aspirin for two weeks. In the case of osteocutaneous grafts, the flaps are monitored by visual inspection of the cutaneous paddle and by Doppler ultrasound. When a skin graft is required to cover the donor site, the patient wears a posterior splint and should remain on non-weight-bearing status for at least 48 to 72 hours postoperatively. After this, a walking boot will help avoid plantar or dorsiflexion of the ankle, thereby preventing shearing of the skin graft from the leg before it has completely healed. At this point, the patient is allowed to bear weight progressively as tolerated.

Complications

Anesthesia-Related Complications

• Pain
• Nausea and vomiting
• Damage to teeth
• Sore throat and laryngeal damage
• Anaphylaxis to anesthetic agents
• Cardiovascular collapse
• Respiratory depression
• Aspiration pneumonitis
• Hypothermia

Intraoperative Complications

• Bleeding
• Errors in graft contouring
• Iatrogenic bone fracture
• Damage to the neurovascular bundle

Postoperative Complications

• Graft fracture (most common complication)
• Infection (second most common complication)[15]
• Hematoma
• Pin migration
• Leg length discrepancy
• Valgus malalignment
• Equinus deformity of the ankle[20]
• Great-toe contracture (flexion contracture of the great toe may require flexor hallucis longus lengthening)
• Motor weakness (attributable primarily to pain)[21]
• Peroneal nerve palsy[7]
• Low hematocrit or hemoglobin levels that require transfusion in the immediate postoperative period[22]
• Delayed non-union
• Growth deformities due to physeal abnormalities or asymmetrical growth[16]
• Inadequate soft-tissue coverage
• Early postoperative wound dehiscence
• Amputation due to failed treatment of the initial source of bone defect or failure of grafting union[23]
• Failure of flap perfusion

Clinical Significance

Because of the fibula's ability to provide up to 30 cm of straight, healthy bone with minimal morbidity at the donor site and minimal postoperative functional limitation, it has become a commonly-used source of grafting material. Applications for fibula grafting run the gamut from oncological resections to chronic infections to post-traumatic defects and congenital anomalies. Direct medialization of the fibula has even been described for reconstructing long tibial defects.[24] Vascularized fibular grafts are particularly useful because they improve the perfusion of the recipient site, which then improves healing, particularly in patients with chronic infection or a history of radiation therapy. Fibular grafting, while technically complicated, has the added advantage of being more rapid and less morbid than the classical Ilizarov technique for addressing leg length discrepancy.[6][24] The indications for fibular grafting are broad, and the surgical techniques vary, and specialists from orthopedics, plastic surgery, otorhinolaryngology, and oral-maxillofacial surgery all rely upon the fibula to solve reconstructive problems in their patients.

Enhancing Healthcare Team Outcomes

Optimizing outcomes for fibular grafting patients requires coordination among interprofessional team members spanning the entire perioperative period, from initial evaluation to long-term follow-up. Sonographers and radiology technicians, as well as radiologists, are crucial for evaluating perfusion to the distal lower extremity before surgery. Primary care providers must ensure patients are healthy enough to undergo a complex and lengthy operation under general anesthesia. Other medical specialists, such as cardiologists, may be required to confirm candidacy for surgery in patients with more complicated medical histories.

Intraoperatively, the surgeon, anesthesia provider, and nursing staff all play critical roles, with surgeons and nurses continuing to provide care throughout the admission. Physical therapists will also contribute to in-hospital care, providing the patient with strategies and techniques for conducting activities of daily living despite the functional limitations of an operated leg.

Postoperatively, the surgeon and outpatient nursing staff, along with a physical therapist, if necessary, will continue to care for the patient until recovery is complete. Fibular grafting is typically performed for complicated defects, and the degree of technical difficulty during surgery is generally commensurate; recovery afterward can be just as challenging. For this reason, having an interprofessional team whose members possess expertise across the spectrum of the patients' needs will minimize complications and optimize functional outcomes. [Level 1]

Nursing, Allied Health, and Interprofessional Team Interventions

Nursing postoperative care should include careful management of intravenous fluids and blood pressure, deep venous thrombosis prophylaxis, pain control, antibiotic administration, Foley catheter management, wound/dressing care, assistance with ambulation, and diet advancement when appropriate.

Nursing, Allied Health, and Interprofessional Team Monitoring

Close postoperative patient monitoring is essential for recognizing early complications, especially the failure of the vascular anastomosis in the case of vascularized grafts. It is important to evaluate the flap regularly, looking for skin mottling, pallor, or ecchymosis, cooling of the skin, increasing edema, decreasing capillary refill, rapid return of dark blood, or no blood at all with skin pricking, or lack of Doppler signal. Additionally, other clinical signs such as hypotension, dizziness, excessive pain, and fever should raise suspicion for an evolving complication and trigger evaluation by the surgeon.