Approach to the fibula

Introduction to the Fibula Approach

The approach to the fibula uses a classic, extensile exposure that provides access to all parts of the bone. This versatile surgical approach is employed for a variety of procedures.

The fibular approach is indicated for:

1. Partial fibular resection during a tibial osteotomy or as part of treating a tibial nonunion.
2. Fibular resection to decompress all four compartments of the leg.
3. Tumor resection.
4. Resection for osteomyelitis.
5. Open reduction and internal fixation of fibular fractures.
6. Harvesting bone grafts, including cortico-cancellous strut grafts.

Patient Positioning

Position the patient laterally on the operating table with the affected side facing upward.

When the fibular approach is used in combination with a procedure on the tibia, place the patient supine on the operating table. A sandbag placed under the affected buttock will internally rotate the leg. Tilting the table away from the operative side further enhances this internal rotation, providing adequate exposure of the leg’s lateral aspect. Afterward, removing the sandbag and leveling the table allows the leg to externally rotate naturally, giving access to the tibia.

Landmarks and Incision

Landmarks:

1. The head of the fibula.
2. The distal quarter of the fibula.

Incision:

• Make a linear incision just posterior to the fibula, starting behind the lateral malleolus and extending up to the level of the fibular head.
• Continue the incision proximally and posteriorly, to a point one handbreadth above the fibular head and in line with the biceps tendon. Exercise caution around the common peroneal nerve, which lies subcutaneously over the fibular neck and can be damaged by an overly vigorous skin incision.
• The length of the incision depends on the required exposure.

Internervous Plane

The internervous plane for the fibular approach lies between:

• Peroneal muscles: Innervated by the superficial peroneal nerve.
• Posterior compartment muscles: Innervated by the tibial nerve.

Superficial Dissection

• To expose the fibular head and neck, begin proximally by incising the deep fascia in line with the skin incision, taking great care not to cut the underlying common peroneal nerve.
• Locate the posterior edge of the biceps femoris tendon as it passes down past the knee before inserting into the fibular head.
• Identify and isolate the common peroneal nerve as it runs behind the biceps tendon; trace its path as it winds around the fibular neck.
• Mobilize the nerve from its groove in the neck by dividing the fibers of the peroneus longus muscle that cover it. Gently retract the nerve anteriorly over the fibular head using a strip of corrugated rubber drain.
• Identify and preserve all branches of the nerve.
• Develop a plane between the peroneal nerve and the soleus nerve. Retract the common peroneal nerve anteriorly and incise the fibular periosteum longitudinally along this plane.
• Continue the incision down to the bone.

Deep Dissection

• Strip the muscles from the fibula by dissection. All muscles originating from the fibula have fibers that run distally toward the foot and ankle.
• To cleanly reflect them, you must therefore elevate them from distal to proximal. Most muscles arise from the periosteum or fascia and can be peeled away.
• Muscles that are directly attached to the bone are more difficult to remove and usually require transection. The other structure attached to the fibula, the interosseous membrane, has fibers that run obliquely upwards.
• To complete the dissection, remove the interosseous membrane subperiosteally from proximal to distal.

Extension of the Approach

The fibular approach can be extended distally:

• Extend the skin incision distally by curving it over the lateral aspect of the tarsus.
• To access the sinus tarsi and the talocalcaneal, talonavicular, and calcaneocuboid joints, reflect the underlying extensor digitorum brevis muscle posteriorly.
• This extension is commonly used for lateral surgeries of the leg and foot.

Dangers

Structures at risk during the fibular approach include:

1. Common peroneal nerve: Avoid injury by performing proximal isolation.
2. Superficial peroneal nerve: Vulnerable to injury at the junction of the middle and distal thirds of the leg. Injury causes numbness on the dorsum of the foot.

References

• Surgical Exposures in Orthopaedics – 4th Edition
• Campbell’s Operative Orthopaedics – 12th Edition