Approach to the Fibula

Approach to the Fibula

The approach to the fibula employs a classic extensile exposure5 and offers access to all parts of the fibula. Its uses include the following:

1. Partial resection of the fibula during tibial osteotomy6 or as part of the treatment of tibial nonunion7,8

2. Resection of the fibula for decompression of all four compartments of the leg9

3. Resection of tumors

4. Resection for osteomyelitis

5. Open reduction and internal fixation of fractures of the fibula

6. Removal of bone graft—corticocancellous strut grafts. Vascularized fibula grafts are dissected out with their vascular pedicles.

Although the bone can be exposed completely, only a part of the approach usually is required for any one procedure.

Position of the Patient

Place the patient on his or her side on the operating table with the affected side uppermost. Pad the bony prominences of the other leg to prevent the development of pressure sores. Exsanguinate the limb by elevating it for 3 to 5 minutes, then apply a tourniquet (see Fig. 11-34). Alternatively, if this approach is used in conjunction with a surgical approach to the tibia, place the patient supine on the operating table. A sandbag placed underneath the affected buttock will rotate the leg internally. Tilting the table away from the operative side will further increase internal rotation and allow adequate exposure of the lateral aspect of the leg. Subsequently, if the sandbag is removed and the table is leveled, the leg will naturally rotate externally, providing access to the tibia.

Landmarks and Incision

Landmarks

The head of the fibula is easily palpable about 2 to 3 cm below the lateral femoral condyle.

The common peroneal nerve can be rolled underneath the fingers as it winds around the fibular neck. The lower fourth of the fibula is subcutaneous.

Incision

Make a linear incision just posterior to the fibula, beginning behind the lateral malleolus and extending to the level of the fibular head. Continue the incision up and back, a handbreadth above the head of the fibula and in line with the biceps femoris tendon. Watch out for the common peroneal nerve which runs subcutaneously over the neck of the fibula and can be cut if the skin incision is too bold. The length of the incision depends on the amount of exposure needed (Fig. 11-42).

Internervous Plane

The internervous plane lies between the peroneal muscles, supplied by the superficial peroneal nerve, and the flexor muscles, supplied by the tibial nerve (see Fig. 11-36).

Superficial Surgical Dissection

To expose the fibular head and neck, begin proximally by incising the deep fascia in line with the incision, taking great care not to cut the underlying common peroneal nerve. Find the posterior border of the biceps femoris tendon as it sweeps down past the knee before inserting into the head of the fibula. Identify and isolate the common peroneal nerve in its course behind the biceps tendon; trace it as it winds around the fibular neck (Fig. 11-43). Mobilize the nerve from the groove on the back of the neck by cutting the fibers of the peroneus longus that cover the nerve and gently pulling the nerve forward over the fibular head with a strip of corrugated rubber drain. Identify and preserve all branches of the nerve (Fig. 11-44).

Develop a plane between the peroneal muscles and the soleus; with the common peroneal nerve retracted anteriorly, incise the periosteum of the fibula longitudinally in the line with this plane of cleavage. Continue the incision down to bone (Fig. 11-45).

Deep Surgical Dissection

Strip the muscle off the fibula by dissection. All muscles that originate from the fibula have fibers that run distally toward the foot and ankle. Therefore, to strip them off cleanly, you must elevate them from distal to proximal. Most muscles originate from periosteum or fascia; they can be stripped. Muscles attached directly to bone are difficult to strip; they usually must be cut (Fig. 11-46, and cross section).

The other structure attached to the fibula, the interosseous membrane, has fibers that run obliquely upward. To complete the dissection, strip the interosseous membrane subperiosteally from proximal to distal (Fig. 11-47, and cross section).

Dang

Nerves

The common peroneal nerve is vulnerable as it winds around the neck of

the fibula. The key to preserving the nerve is to identify it proximally as it lies on the posterior border of the biceps femoris. It then can be safely traced through the peroneal muscle mass. If possible, avoid retracting the nerve. The dorsal cutaneous branch of the superficial peroneal nerve is susceptible to injury at the junction of the distal and middle thirds of the fibula; if it is damaged, it causes numbness on the dorsum of the foot.

Figure 11-42 Make a long linear incision just posterior to the fibula.

Figure 11-43 A: Expose the common peroneal nerve in the proximal end of the incision along the posterior border of the biceps. B: Continue exposing the common peroneal nerve distally as it winds around the neck of the fibula in the substance of the peroneus longus.

Vessels

Terminal branches of the peroneal artery lie close to the deep surface of the lateral malleolus. To avoid damaging them, you must keep the dissection subperiosteal.

The small (short) saphenous vein may be damaged; you may ligate it if necessary.

How to Enlarge the Approach

Local Measures

The exposure described allows exposure of the entire bone.

Extensile Measures

Distal Extension. Extend the skin incision distally by curving it over the lateral side of the tarsus. To gain access to the sinus tarsi and the talocalcaneal, talonavicular, and calcaneocuboid joints, reflect the underlying extensor digitorum brevis muscle. This extension is used frequently for lateral operations on the leg and foot (see Lateral Approach to the Hindpart of the Foot in Chapter 12).

Figure 11-44 Retract the peroneal nerve anteriorly, and incise the fascia between the peroneal muscles and the soleus muscle.

Figure 11-45 Develop the intermuscular plane between the peroneal muscles and the soleus muscle down the lateral edge of the fibula. Strip the flexor muscles from the posterior aspect of the fibula in a distal to proximal direction.

Figure 11-46 Strip the flexor hallucis longus and the soleus from the posterior aspect of the fibula, and strip the peroneal muscles from the anterior surface of the fibula in a distal to proximal direction. Strip the flexor muscles from the posterior aspect of the fibula (cross section). Avoid neurovascular structures by staying close to the bone.

Figure 11-47 Retract the peroneal muscles anteriorly. Strip the interosseous membrane from the anterior border of the fibula in a proximal to distal direction. Strip the muscles from the anterior surface of the fibula, and strip the interosseous membrane from its fibular attachment in a proximal to distal direction (cross section).