Evaluate the extensor mechanism; obtain orthogonal radiographs of the tibia, ankle, and foot; and carefully assess the vascular supply distal to the zone of injury.

Patients do not require an angiogram if the posterior tibial artery is normal on examination. Doppler evaluation can confirm the patency of the posterior tibial artery, and a strong triphasic signal precludes angiography.

The pedicle flap can be based on the anterior tibial artery by preserving the communication of the anterior and posterior tibial arteries through the dorsalis pedis and the deep plantar arch of the foot. However, if the posterior tibial artery is not palpable on examination, obtain an angiogram to determine the vascular supply distal to the traumatic zone and to prepare for conversion to a composite free microvascular transfer.

Consult with a specialist in plastic surgery. Our initial procedures were performed in conjunction with the plastic surgery department. Although the pedicle flap procedure can be done with a knowledge of the anatomy of the lower limb, make sure a microsurgical team is available if the pedicle fails and requires conversion to a free microvascular composite flap transfer.

Position the patient supine on a radiolucent operating table, and apply a tourniquet to the proximal part of the thigh.

Provisional stabilization of the damaged limb is ideally achieved by external fixation or internal fixation with a plate. Remove these implants before you develop the pedicle flap and minimize the surgery about the knee.

Elevate the leg to exsanguinate it by gravity, and inflate the tourniquet to 100 mm Hg above the systolic blood pressure. Extend the traumatic wound along the lower leg in line with the posterior-medial border of the tibia, curving distally at the level of the medial malleolus parallel with the course of the posterior tibialis tendon. Continue the surgical incision along the medial side of the foot, turning it at a right angle just distal to the sesamoids and along the distal aspect of the plantar fat pad to the head of the fifth metatarsal.

The dissection about the tarsal tunnel is the critical portion of the operative technique. A number-10 scalpel is the instrument of choice. Incise the deltoid ligament sharply and resect the posterior tibial, flexor hallucis longus, and flexor digitorum longus tendons to leave the posterior tibial nerve and artery as the remaining structures in the tarsal tunnel (Figs. 2-A and 2-B). Protect the neurovascular bundle with a vessel loop. It is important to preserve tibial nerve function to preserve a sensate foot.

Excision of the talus greatly simplifies the procedure. Remove the talus by incising the robust soft-tissue attachments, while maintaining tension with a large Weber clamp on the talus. This exposes the calcaneus and facilitates access to the neurovascular bundle as it courses to the deep plantar arch.

Following removal of the talus, direct the scalpel distally along the plantar cortex of the navicular, along the medial cuneiform and along the plantar surface of the first metatarsal. Return the dissection to the Chopart level and incise the attachments with the navicular and cuboid to remove them, leaving the calcaneus alone in continuity with the plantar flap.

The posterior tibial artery arborizes with the deep plantar arch in the interosseous muscles of the foot such that “keeping to bone” on the plantar surface of the midfoot and forefoot will preserve the vascular tree. We recommend sharp dissection with a scalpel, avoiding electrocautery to minimize thermal necrosis and increased wound burden. Sharply divide the interosseous muscles along the metatarsals from the medial arch to the plantar aspect of the fifth metatarsal. Resect the first metatarsal, carefully preserving the dorsalis pedis artery as it descends between the bases of the first and second rays. Preservation of the dorsalis pedis artery is essential in the absence of a patent posterior tibial artery. In this situation, you can consider conversion to a free tissue transfer.

Remove the lesser metatarsals and toes to separate them from the calcaneal composite flap (Fig. 2-C). Retain lateral hindfoot soft tissue. Keep the flap warm and moist with saline solution-soaked sponges.

Contour the calcaneus with an oscillating saw. Resect the posterior facet parallel to the plantar aspect of the bone at the articular junction of the facet with the tuberosity, and resect the anterior process immediately proximal to the calcaneocuboid articular surface perpendicular to the long axis of the calcaneus. Cut the medial sustentaculum, including a good portion of the middle facet, flush with the medial border of the calcaneus (Figs. 3-A, 3-B, and 3-C).

Osseous resection as described transforms the undulating form of the heel into a box shape. The osteotomy at the distal end of the calcaneus will determine the alignment of the limb following osteosynthesis with it to the tibia. Any deviation from perpendicular will translate to an axial deformity in the reconstructed limb.

Sharply dissect the intercalary soft tissue and the remaining bone from the proximal fracture in the tibia and from the ankle, leaving a cuff of soft tissue about the posterior neurovascular bundle. A vascular clip is useful for managing small perforators emanating from the artery. Do not skeletonize the bundle. In cross section, it is slightly smaller than a large Penrose drain (approximately 0.5 × 1.5 cm).

Osteotomize the proximal part of the tibia transversely, adjacent to the inferior aspect of the tibial tubercle, using an oscillating saw (Fig. 4). Transect the gastrocnemius and soleus muscles at this level or distally, on the basis of their viability. Resect the fibula obliquely at the level of the tibial osteotomy.

Release the tourniquet to assess the viability of the pedicle flap and to manage substantial bleeding. Achieve hemostasis with gentle compression of the flap and minimal electrocautery. The pulse is visible, and bright red bleeding is noted at the distal cut edge of the plantar pedicle flap. Remove the flexor tendons and the volar plates from the sole of the foot (Fig. 5-A). Cutaneous circulation in the lateral foot area can be sluggish, as this is the distal extent of the collaterals to a watershed area predominantly supplied by the extinct peroneal artery.

Gently coil the posterior tibial artery, vein, and nerve in a large loop and rotate the calcaneus cephalad with its distal end, the anterior process, mated to the remaining inferior part of the tibia. Rotate the calcaneus slightly about its long axis to position the sole of the foot in the most desirable location based on the coverage needs dictated by the zone of injury.

Initially, we used a 90-90 wiring technique for osteosynthesis (Fig. 5-B), which was supplemented with an early postoperative plaster cast. For several years, we have used a six or seven-hole large-fragment dynamic compression plate instead. Apply the plate to compress the calcaneus to the tibia in a position that favors optimal position of the sole as it rests on the anterior aspect of the limb (Figs. 5-C and 5-D). In most circumstances, the plate rests on the medial surfaces of the tibia and calcaneus.

Use intraoperative radiography to ensure reasonable alignment of the reconstruction. Prosthetic management can compensate for most minor malalignments. Avoid varus angulation and, especially, recurvatum. A prominent calcaneus with an axis anterior to the anatomic extension of the tibia complicates prosthetic management and may substantially alter gait.

Close the soft tissues in layers.

Completion of the tibiocalcaneal osteosynthesis leads to insetting of the flap and contouring of the limb. The adjacent soft-tissue planes are paired so that layered closure may be performed and mismatch of adjacent tissue contours is minimized.

The injured limb is routinely very swollen, and in some cases complete coverage requires some split-thickness skin-grafting. Skin-grafting can be done at the time of the pedicle graft or deferred for a few days (Fig. 6). When it is delayed, use a negative-pressure-dressing technique to reduce the edema and maintain wound hygiene and viability.

Dress the limb with nonadherent medicated gauze, bulky absorbent pads, and a compressive circumferential wrap. Dress skin grafts with a negative pressure dressing, or provide a bolster with Xeroform gauze (Covidien, Mansfield, Massachusetts) and cotton balls soaked in mineral oil. Apply a thick posterior plaster splint with the knee in full extension.

Elevate the limb and mobilize the patient with a walker on postoperative day two. Inspect the wound on approximately day five. Perform dressing changes as needed, and apply a compressive wrap and/or a limb shrinker, which should be used continuously for several weeks.

The initial reconstruction is sometimes extremely bulbous (Fig. 7-A). Thoughtfully counsel the patient and continually advise him or her that the shape will improve dramatically over time with shrinkage of the limb (Figs. 7-B and 7-C).

Physical therapy for quadriceps training and knee range of motion and a program of limb sensitization are recommended. Obtain biplanar radiographs at six to eight weeks to assess stability and healing of the tibia and calcaneus. Patients are generally ready for a temporary prosthesis and weight-bearing at eight to ten weeks.

Open tibial fracture with or without bone loss extending to the proximal tibial metaphysis

Soft-tissue loss in excess of potential coverage with a conventional single free tissue transfer OR inadequate durable soft-tissue coverage with conventional transtibial amputation

Intact arterial supply to the hindfoot, including the plantar surface

Comminuted calcaneal fracture

Plantar degloving injury or devascularization

Deficient knee extensor mechanism

Injury to the posterior tibial artery. Preoperative angiography is performed if there is any question regarding the patency of the posterior tibial artery. A complete or partial injury of the posterior tibial artery may necessitate development of the flap with the anterior tibial artery or conversion of the pedicle to a free tissue transfer.

Proximal tibiofibular dislocation. Ideally, the proximal part of the fibula is retained and reduced and secured to the tibia with small-fragment screws to preserve knee function (Figs. 5-C and 5-D).

Infection. The risk of early infection is minimized by meticulous, serial surgical debridement and definitive flap transfer within five to ten days. Intravenous antibiotics and negative pressure dressings may reduce the risk of infection prior to the definitive procedure.

Insufficient soft-tissue coverage after the flap is secured. These areas may occur medially and/or laterally. Negative pressure dressings may be used to control edema and to facilitate healing of small open portions of the wound over healthy muscle by secondary intention. Larger areas may be treated with split-thickness skin-grafting.

A delay in the decision to perform this procedure. A delay of more than six weeks results in inflammation and stiffness of the neurovascular bundle, making it difficult to coil and contain these structures within the soft tissues proximally as the flap is secured.

This technique is ideally indicated for patients with a large zone of injury involving the tibia, excluding non-repairable damage to the knee extensor mechanism and trauma to the foot. The pattern of injury is typical of a pedestrian or motorcyclist struck by the bumper of a motor vehicle.

The flap relies on a patent artery to the foot, most commonly the posterior tibial artery. In two of our cases, the pedicle procedure was successfully converted to a free tissue transfer. The transition to a free flap represents a major change in surgical approach, and planning for the contingency will lessen the difficulties involved in such a change.

Lateral hindfoot and ankle skin is often redundant but marginally viable (Fig. 9-A). The lateral skin often becomes nonviable following the loss of its primary blood supply and should not be relied on to cover an area more than a few centimeters from the calcaneus. Coverage of questionable areas with skin graft is preferable to “stretching” the lateral skin of the composite flap.

The limb has a bulbous shape that seems less natural than a typical transtibial amputation. The patient will find the appearance different and strange. The end of the limb is clearly identifiable as a foot, sensation is almost universally retained, and patients may be viewed by those to whom the limb is visible as having an altered human form. Patients will benefit from psychological counseling through the rehabilitation as they adapt to the function and appearance of the limb.

Remodeling of the limb in the first year often leads to crevice formation at the junction of the sole and the residual limb (Fig. 9-B). Perspiration accumulates in these areas. Revision at the margins of the flap with excision of grafted/scarred areas and primary repair reduces this problem and improves the appearance of the limb.

The calcaneal tuberosity is not tapered, so patients with a long residual limb may require an endoskeleton that has less of a taper than the normal limb. Matching the skin tones of the endoskeleton improves the cosmetic appearance. Attention to the overall length of the reconstructed limb will minimize the difference in the shape of the prosthesis.