Open tibial fractures present with a wide spectrum of soft-tissue injuries and associated bone loss. Reconstruction of a functional limb is often a complex process that may require soft-tissue reconstruction techniques, including free tissue transfer and its associated risks, to manage the soft-tissue injury. In addition, bone loss, if appreciable, may require massive bone-grafting, bone transport, or free vascularized bone transfer to obtain a durable union. In these cases, successful limb salvage is never guaranteed and an extended period of time may be required to achieve a functional extremity1. Amputation, in these cases, may result in an equally successful functional outcome2. When possible, a below-the-knee amputation is the preferred amputation level because it has recognized functional benefits and is associated with decreased energy requirements for the amputee during activity3. Durable soft-tissue coverage and maintenance of appropriate length of the residual limb are paramount in maintaining an optimal outcome4. Unfortunately, the often high-energy mechanism of injury results in an extensive zone of injury. In some instances, the attainment of adequate bone and soft-tissue coverage may require the use of the same techniques that are utilized for limb salvage, which may result in suboptimal coverage and length to afford functional use of a prosthesis. Faced with these reconstruction dilemmas, amputation at a higher level is often the surgical choice.
We report the case of a patient with an open Gustilo-Anderson type-IIIB tibial fracture with extensive soft-tissue loss and an associated bone loss of approximately 17 cm. The patient, not desiring limb salvage with free tissue transfer or bone transport and not wishing to undergo an above-the-knee amputation, elected to undergo a below-the-knee amputation with complex local and osseous soft-tissue reconstruction. An optimal-length residual limb with durable soft-tissue coverage was obtained through the creation of an osteocutaneous turn-back flap that included the distal part of the tibia and the foot. The final outcome was a substantially lengthened, sensate and functional residual limb at the below-the-knee level. To our knowledge, this technique has not been reported in the literature regarding reconstruction of acute open lower-extremity injuries requiring amputation. The patient and her parents were informed that data concerning the case would be submitted for publication, and they consented.
A fifteen-year-old girl was a passenger on an all-terrain vehicle that was involved in a collision with a pickup truck. The patient was initially received by a local rural hospital and was subsequently transferred to our level-one trauma center for definitive management of her injuries. The patient presented in hypovolemic shock, and resuscitation measures were undertaken. Initial evaluation revealed grossly contaminated open fractures of the right tibia and fibula, an open knee joint, an open first metatarsophalangeal dislocation of the right foot, and an open fracture of the right iliac crest. A tourniquet, which had been applied prior to transporting the patient to our facility, was removed, and perfusion was restored to the distal part of the extremity.
The lower extremity distal to the open wound was perfused and continued to remain warm and sensate, although the dorsalis pedis and posterior tibial pulses were not palpable. There was a large open wound on the anteromedial aspect of the leg and additional lacerations about the knee. The skin at the medial aspect of the mid and proximal portions of the leg was noted to be ischemic, with posterior and circumferential extension of the ischemia. The large traumatic wound was contaminated with gravel and organic material. An arthrogram of the knee confirmed the presence of an open joint injury. Radiographs of the involved extremity demonstrated a comminuted tibial shaft fracture, a Schatzker type-I intra-articular fracture of the proximal part of the tibia5,6, a segmental fibular fracture, and a proximal fibular head dislocation. Following application of a sterile dressing, a splint was applied, antibiotic therapy with intermittent infusion of gentamicin and vancomycin was initiated, and tetanus prophylaxis was administered.
The patient was taken emergently to the operating room, where an extensive irrigation and débridement was performed followed by immobilization of the extremity with a unilateral external fixator placed across the knee. Following débridement, the open tibial fracture was classified as Gustilo-Anderson type IIIB7,8 (Fig. 1). Radiographs demonstrated a 17-cm segmental bone loss extending from the tibial tubercle to the distal tibial diaphysis (Fig. 2). In preparation for limb salvage with free tissue transfer, an angiogram was performed, which showed that the vascular flow through the tibialis anterior, tibialis posterior, and peroneal arteries was intact. Irrigation and débridement was performed on the day of admission and on the fourth and sixth day after admission to treat progressive necrosis of the skin at the medial and posterior aspects of the proximal portion of the leg with a corresponding partial loss of the anterior lateral and deep posterior muscle compartments. The foot remained sensate and well perfused at the completion of all procedures. Negative pressure dressings were applied between débridements.
The patient and her family were extensively educated about all treatment options throughout the hospital course. Treatment options discussed included both soft and osseous free tissue transfer, bone transport, and amputation of the extremity. The patient and the family were not in favor of the free tissue transfer options, nor did they desire bone transport for limb salvage. The patient preferred to avoid possible complications associated with alternative treatments, including additional hospitalizations, donor-site morbidity associated with flap harvest, multiple operations, long recuperation time, and possible graft-flap failure. These considerations effectively limited the treatment options to an amputation. The family also spoke with a local female college student who had undergone a below-the-knee amputation. This conversation was particularly useful and alleviated much of the family's apprehension regarding functional status after an amputation. The family wished for the residual limb to remain at the below-the-knee level if possible. Faced with the challenge of maintaining a residual limb at the below-the-knee level while avoiding free tissue transfer, we investigated the possibility of using the remaining local tissue as a source for reconstruction of the soft tissue and restoration of tibial length in order to obtain functional results with a below-the-knee amputation. The distal aspect of the leg was relatively free of injury, and the foot remained sensate and well perfused. We decided to use this viable tissue as a rotational tibial turn-back flap to achieve functional results with a below-the-knee amputation.
Surgical Technique
The patient was taken to the operating room for the amputation procedure eight days after the initial injury. The vessels of the distal aspect of the limb were found with use of Doppler ultrasound and their location was traced on the skin of the foot. A fillet flap of the foot was created with use of a similar technique to that described by Patterson et al.9. A longitudinal incision was begun at the distalmost aspect of the traumatic wound, just medial to the tibial crest, and was continued distally over the first and second intermetatarsal spaces of the foot (Fig. 3-A). Sharp dissection was carried down to the periosteum of the tibia and directly to bone in the foot. A fillet flap of the foot was created by first disarticulating all of the toes at the metatarsophalangeal joints and then amputating them. Subperiosteal dissection and skeletonization of the entire foot was then achieved. At that point, only the soft tissues of the foot remained as full-thickness soft-tissue flaps that were contiguous with the extraperiosteal dissection of the medial and lateral soft tissues about the distal part of the tibia. The soft-tissue attachments were maintained on the posterior aspect of the distal portion of the tibia, and the association between the tibia and the posterior tibial artery was safeguarded. The ankle joint was disarticulated from the distal portion of the tibia. The neurovascular structures remained intact in the soft-tissue flaps. The distal aspect of the remaining fibula and the distal fibular fracture segments were then excised and removed. The medial malleolus was then removed flush with the medial border of the tibia with an oscillating saw, and the articular surface of the distal part of the tibia was removed (Fig. 3-B).
The turn-back flap was placed on warm saline-solution-soaked laparotomy sponges, and the osseous reconstruction of the proximal tibial segment was initiated. The tibial plateau fracture was reduced and fixed with two lag screws. The proximal tibiofibular joint dislocation was reduced and fixed with a screw. The distal aspect of the proximal segment of the tibia was then trimmed flush at the level of the lowest portion of the tibial tuberosity. It was ascertained that the distal flap was viable on the basis of skin color, warmth, and capacity to bleed. As the flap was turned back (Fig. 3-C), the decorticated distalmost aspect of the tibia (the plafond) rotated with the flap and was approximated to the metaphyseal portion of the proximal segment of the tibia. The flap remained viable, and arterial signals in the distalmost aspects of the fillet flap were confirmed with Doppler ultrasound. The residual fibula was then trimmed with an oscillating saw to a level slightly shorter than the combined length of the proximal tibial segment and the turned-back distal tibial segment. The distalmost aspect of the tibia, now reversed in orientation, was impacted into the metaphyseal portion of the tibia. A locking compression plate (Synthes, Paoli, Pennsylvania) was used to secure the two segments of tibia. The distal aspect of the residual fibula was then placed in a position to restore its normal interosseous distance from the tibia and secured with a 3.5-mm cortical screw (Fig. 3-D). The medial and lateral flaps of the foot fillet were utilized to obtain coverage on the corresponding surfaces about the proximal portion of the tibia. Excellent cutaneous coverage was obtained. The excess distal tissue from the sole of the foot was removed and discarded. The skin was then closed loosely with 3-0 nylon sutures. All turned-back tissue appeared viable (Fig. 4), and Doppler ultrasound testing showed that arterial flow remained present in the turned-back arteries. Standard dressings were applied, and the knee of the residual limb was immobilized in extension.
Postoperative Course
On postoperative day 4, a small area of necrotic skin developed. The antibiotics were changed to oral levofloxacin and intravenous cefazolin, which were continued through day 14. On day 6 after the amputation, the patient was returned to the operating room for evacuation of a hematoma and débridement of necrotic skin and subcutaneous tissue at the posterolateral aspect of the residual limb, adjacent to the original zone of injury. In both the area of hematoma removal and the area of débridement, the underlying gastrocnemius muscle remained viable. Negative pressure dressings were applied to the open wound and changed three times per week. Definitive coverage of the granulating area (approximately 2 cm × 2 cm) was achieved with the application of a split-thickness skin graft. Knee range-of-motion exercises were initiated four weeks following the amputation, when soft-tissue healing had occurred.
The patient was fitted with a prosthesis three months after the amputation and reconstruction. At the eight-month follow-up, the patient reported minimal to no pain and had no phantom limb pain. Knee range of motion was from full extension to 110° of flexion (Fig. 5). The limb was sensate with the exception of a small area of decreased sensation on the medial side of the distal aspect of the residual limb. Radiographs made at the time of the one-year follow-up showed maintenance of reduction, absence of hardware failure, and osseous union at the juncture of the two tibial segments. Heterotopic bone formed in the distal aspect of the residual limb (Figs. 6-A and 6-B). As a wearer of a prosthesis, the patient was able to perform all activities of daily living and had returned to competitive volleyball at the high-school level (Fig. 7).
Limb salvage or amputation is a frequently debated issue with regard to a mangled lower extremity. Either route is challenging because of the extensive zone of osseous and soft-tissue injury. When reconstruction is not feasible, amputation becomes the primary means to achieve a functional outcome. The goal of amputation should be to provide the amputee with a residual limb of maximal length and a durable soft-tissue envelope.
The results of the Lower Extremity Assessment Project indicated that functional results were improved in the cohort of patients who received amputation at the below-the-knee level when compared with the results of patients who underwent amputation at the above-the-knee level, and that functional outcomes were similar between patients who underwent amputation at the below-the-knee level and those who underwent limb salvage1. With regard to level of amputation, higher-level amputations have generally been associated with increased difficulty with prosthetic wear, slower ambulation rates, abnormal gait, and decreased functional results3,10. In light of these findings, all means to maintain the amputation at a below-the-knee level should be considered11. The maximally lengthened stump allows improved gait and increased proprioception and provides increased mechanical advantage to the prosthesis12. The best functional outcomes are achieved when the residual limb is comprised of a tibia with a length that is approximately 2.5 cm for every 30 cm of body height13.
To our knowledge, there has been no report of the use of a composite pedicle distal tibial turn-back flap and fillet flap of the foot for salvage of a mangled lower extremity at the below-the-knee amputation level for acute reconstruction of a mangled extremity. The concept of reconstruction through the utilization of available undamaged tissue or so-called spare parts of an amputated extremity has been reported by Jupiter et al.14. For two patients, the amputated and undamaged foot was filleted and utilized as a free tissue transfer to obtain soft-tissue coverage of a degloved residual proximal section of tibia as a way of salvaging a below-the-knee amputation level. This procedure became possible because of microsurgical techniques and requires nerve repair to provide sensate coverage. Ghali et al. reported on a series of patients in whom leg length was preserved with use of pedicled fillet flaps of the foot after traumatic amputation11. Küntscher et al. described, analyzed, and classified the use of pedicled flaps in diverse situations, including leg-length preservation in eight patients who underwent below-the-knee amputation15. Osseous reconstruction was not required in these patients, and the osseous structures were removed from the distal flap.
The practice of enhancing a below-the-knee amputation with distal osseous structures has been described previously in situations in which the presence of tumor or infection necessitated extensive resection of the proximal tibial diaphysis16. Younge and Dafniotis turned the distal tibial segment back and attached it to the short proximal segment of tibia to successfully achieve a longer amputation stump17. Their procedure was also similar to the one that we report here in that the use of the intact posterior soft tissues negated the need for microvascular techniques and dissection of neurovascular structures. The technique we present is different in that we included the filleted foot for additional soft-tissue coverage and performed the procedure in the period of the initial hospitalization, whereas the previously reported techniques were performed in the delayed-care setting. In the acute-care setting, it is imperative that the zone of injury be well defined over the course of several débridements to prevent soft-tissue loss after the reconstruction procedure. In our patient, the loss of tissue following reconstruction was minimal, suggesting that the soft-tissue injury had been well defined and débrided.
The success of this procedure also depends on an adequate blood supply to the distal aspect of the tibia and the surrounding soft tissues. Whereas the region surrounding the tibial diaphysis is relatively hypovascular and the tibial diaphysis has few extraosseous vessels posteriorly, the distal aspect of the tibia receives the majority of its extraosseous arterial supply from the posterior tibial artery. At the most distal aspect of the tibia, the tibial plafond and the area immediately proximal to the tibial plafond receive numerous extraosseous branches from the posterior tibial artery18. Additionally, it has been suggested that with the loss of the nutrient artery, as occurred in the case of our patient, the physiological environment can change to allow the metabolic needs of the bone to be met by the extraosseous vessels19. Hence, when the extraosseous arterial supply to the distal aspect of the tibia remains intact and based on the posterior tibial artery, the local environment makes the distal portion of the tibia ideal as a component of a turn-back flap.
One alternative to this procedure would be to implant the distal segment of the tibia without rotating it. This would have allowed the durable skin of the heel pad to remain near the distal aspect of the residual limb. However, the rotational technique employed in the case of our patient afforded two benefits. One benefit was the extent of the bone contact at the tibial reconstruction. Turned 180° on its longitudinal axis, the decorticated tibial plafond achieved a wider area of contact than would have been possible with implantation of the diaphyseal tibia without rotation. The other benefit was the durable coverage obtained with the fold-back flap. Although the heel pad was not the most distal aspect of the residual limb, the fold-back flap provided what has proven to be a durable residual limb and the filleted foot flap provided excellent coverage of the proximal soft-tissue defects while avoiding the need for extensive skin-grafting. In general, large or extensive skin grafts have proven to provide less durable coverage than native skin. In the case of our patient, a small split-thickness skin graft (2 × 2 cm) was required to achieve final coverage on the posterolateral aspect of the residual limb. The work of Dedmond and Davids supports this approach, suggesting that a focal skin graft in a young person or child is able to withstand the thermal and mechanical stresses that result within the socket with enough reliability for its use to be advocated for salvage of a below-the-knee level of amputation20.
The described procedure resulted in a residual limb that was well shaped, sensate, and durable. We believe that the residual tissue of a mangled extremity, including osseous structures, should be preserved and considered for use in reconstruction. The use of these tissues may avoid the need for free tissue transfer and may be particularly useful in restoring functional length and soft-tissue coverage to a limb that would otherwise require amputation at a higher level. 