Salvage of Pilon Fracture Nonunion and Infection with Circular Tensioned Wire Fixation

Foot Ankle Clin N Am 13 (2008) 29–68

Salvage of Pilon Fracture Nonunion and Infection with Circular Tensioned Wire Fixation James J. Hutson, Jr, MD Department of Orthopedic Surgery, University of Miami, P.O. Box 16960 D-27, Miami, FL 33101, USA

Nonunion, malunion, and infection are complications encountered when treating fractures of the distal tibia extending into the joint surface. There is rank order of severity of those complications extending from a varus collapse of the medial column of the distal tibia with a reduced joint surface to an infected nonunion with destruction of the joint surface, segmental bone loss, and damaged soft tissue envelope. Malunion and malposition of nonunion of the distal tibia have a combination of angular deformity, translation, rotational malalignment, and shortening (Fig. 1). These deformities require correction in the reconstruction and there are multiple technique pathways to achieving a successful reconstruction. Soft tissue fibrosis and contractures of the ligaments and tendons of the ankle and lower leg may cause unforeseen problems after bone realignment (Fig. 2). A foot in plantar grade position with an apex posterior metaphyseal deformity has an equines deformity when the foot position is compared with the joint surface of the plafond. Correcting this deformity and reestablishing anatomic length result in flexion contracture of the great and lesser toes, inversion of the foot, and equines deformity. After bone reconstruction, an extensile soft tissue release may be required to return the foot to a plantar grade position. After many months of non–weight bearing, a foot can have midfoot varus and cavus deformity, which need to be addressed when considering foot position when using ankle arthrodesis as the salvage pathway. There may be impaction injuries of the subtalar joint and navicular talar joint or a calcaneus fracture associated with a pilon fracture (Fig. 3). These injuries compromise foot function and lower the final functional score. Plating of the fibula as the first step in pilon fracture management is common

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Fig. 1. Pilon nonunion has angular deformity, translation, rotational malalignment, and shortening. The joint surface can be fragmented and malaligned. (Courtesy of Lignum Designs/ J. Hutson MD, Coral Gables, FL; with permission.)

practice. Reconstruction of the lateral malleolus to length demands that the tibial column be reconstructed to length (Fig. 4). An intact fibula associated with a nonunion of the tibia column causes a varus collapse if the tibia fibula ligament complex is intact. If the lateral tibia fibula ligaments and syndesmosis are disrupted, a fibula plus deformity develops in which the lateral malleolus impinges on the lateral wall of the calcaneus and peroneal tendons. The plafond joint surface has subsided proximally because of nonunion of the comminuted tibial metaphysis. Reconstruction of this deformity includes a correction of this fibula plus malalignment. Bone loss and relative bone loss from comminution of the metaphysis causes nonunion and collapse. Reconstruction requires that the bone deficit is reconstructed by local bone grafting, bone transport, or combinations of shortening and lengthening. Necrotic bone at the nonunion site has no chance of healing with callus. Removal of dead bone to bleeding bone is essential to establish union. Eradication of infection is the fundamental key to any salvage of an infected nonunion of a pilon fracture. A successful reconstruction never is possible without the complete removal of all infected necrotic bone and contaminated soft tissue. The extent of necrotic bone can involve the entire plafond and have extension to the midshaft. The largest defect observed is 17 cm involving the plafond to the midshaft. There are patterns of bone loss that require excision (Fig. 5). The most common is necrosis and infection of the metaphysis with the joint surface and distal plafond viable. The amount of viable

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Fig. 2. Apex posterior deformity of pilon fracture nonunion. Correction of the deformity can cause equines and flexion contracture of toes. The forefoot may have varus. The tendons crossing the ankle can be involved in the fibrosis associated with a pilon fracture nonunion. Observe that the tendons are adjacent to the fracture callus and the flexon hallucis longus is especially vulnerable adjacent to the posterior plafond. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

bone remaining that can be fixated with tensioned wires is approximately 2 cm. Careful exploration is required of the plafond joint fragment to discover necrotic portions that extend into the joint. If there is infection in a portion of the plafond with extension into the joint, then the joint fragment is lost. The second group of infected nonunion is the pilon nonunion with extension of necrosis and infection to the joint of the ankle. The entire infected plafond requires excision. A pattern is observed combining necrosis of the plafond and talus. Only the dome of the talus may be involved, or the entire talus can be necrotic. This rare extensile ankle infection is reconstructed with a tibial calcaneal arthrodesis. Patients present with chronic osteomyelitis from infected pilon fractures treated many years in the past. There is a sequestrum and involucrum. Excision of the sequestrum and treatment with antibiotic beads, flaps, and intravenous antibiotics is possible if there is structural integrity of the involucrum. The infection can be

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Fig. 3. Fractures of the dome of the talus, talar navicular joint, and subtalar joint affect the foot and ankle function. These insidious fractures often are overlooked when there is a spectacular pilon fracture proximal. Crushing of the posterior capsule and facet by the pilon posterior fragment causes local damage, which can lead to synostosis and loss of hindfoot motion. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

Fig. 4. Fibula fixation can lead to two nonunion deformity patterns. If the tibia fibula ligaments are disrupted, the comminuted plafond can deform axially causing a fibula plus malunion with calcaneal impingement. If the ligaments are intact, nonunion and bone loss of the metaphysis cause the plafond to deform in varus collapse. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 5. Bone loss and necrosis patterns observed in pilon infected nonunions are metaphyseal, terminal plafond, plafond and talus, and chronic osteomyelitis from infected pilon fractures sustained many years before. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

invasive through the involucrum and a wide excision of the metaphysis or plafond is indicated to eradicate the infection. The last infection/necrosis pattern observed is septic arthritis after a pilon fracture with viable plafond and metaphyseal bone. The involved joint surface bone is excised and the joint salvaged with an arthrodesis (Fig. 6).

Fig. 6. Septic arthritis after a pilon fracture can involve the joint with the plafond viable. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Many nonunions of pilon fractures have had a free flap or local flap during the initial fixation of the pilon fractures. Free flaps are associated with pilon fractures treated with open reduction and plate fixation. De´bridement of pilon nonunions requires elevation of the flap (Fig. 7). The flap is elevated on the distal end with care to avoid dissection and elevation at the flap pedicle. Prior operative report of the flap anastomosis site is necessary to know precisely the vascular pedicle route through the soft tissues. This information also is necessary when applying the circular fixator to avoid impaling the pedicle with wires and pins. Partial flap elevation exposes the necrotic bone and infected hardware. Review of literature There are few articles on the treatment of nonunion, malunion, and infection of pilon fractures. The treatment pathways vary widely and different techniques are used throughout the small cohort groups. To analyze the data graphically, these articles are presented in an illustrative format to give readers a visual composite of what technical approaches and sequence of treatment are followed to treat nonunion, malunion, and infection of pilon fractures. The drawings are an approximation of the surgical techniques used by the authors of the articles presented and readers are encouraged to review the articles for further detail. The articles are presented in an order of increasing complexity of the pilon fracture complication cascade: varus collapse of the metaphysis to infection, bone loss, and soft tissue compromise.

Fig. 7. The free flap always is elevated on the distal end of the flap opposite the vascular pedicle. The anastomosis site and vessel used to supply the flap must be known before surgery. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Chin and colleagues [1] reviewed the treatment of seven pilon fracture nonunions which were treated with revision plating and bone grafting (Fig. 8). Open fracture comprised 3/7 of the cohort as the initial injury and this association of open fracture will be evident in the subsequent reference treatment series. In the use of plates as a reconstruction technique, there are no infections treated in the series. Removal of the fibula plate and osteotomy of the fibula is necessary to realign the tibia in anatomic position. De´bridement to bleeding bone is a fundamental technique common to all treatment series. The surgical approaches used are medial, anterior lateral, and direct lateral with fibula excision. Bone graft to stimulate healing is used in seven of seven cases. A fixed device (blade plate) provides essential fixation stability and fibula fixation is avoided. One patient is treated with arthrodesis. Healing time is 3 to 5 months. A successful outcome is observed in all nonunions. This technique is applicable to pilon nonunions with good soft tissues, minimal bone loss and no infection. Reed and Mormino [2] treated 11 distal tibia nonunions; six were the results of pilon fracture treatment (Fig. 9). The treatment strategy was similar to the prior series. The incidence of initial open fracture soft tissue injury has increased to 7 of 11 nonunions. Fibula osteotomy is necessary to realign tibia. Initial cases used fibula fixation, but this was discontinued to isolated blade plate fixation of the tibia. Not all initial attempts at reconstruction were successful. Two patients did not heal and collapsed into malunion and one patient had postoperative infection. Loss of dorsiflexion and subtalar motion is observed in functional foot score. As the severity of the pilon nonunion increases in subsequent articles, this loss of ankle and hind foot motion will become profound. Harvey and colleagues [3] described the treatment of periarticular nonunions, 12 of the cases were distal tibia nonunions (Fig. 10). Six of twelve

Fig. 8. Summary illustration: Chin and colleagues [1]. Salvage to the distal tibia metaphyseal nonunions with 90 degrees cannulated blade plate. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 9. Summary illustration: Reed and Mormino [2]. Functional outcome after blade reconstruction of distal tibia metaphyseal nonunions: a study of 11 cases. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

distal tibias are infected requiring an initial aggressive de´bridement and treatment of the infection before proceeding to reconstruction. The technique of wide excision of necrotic bone, removal of hardware, application of antibiotic beads, and intravenous antibiotics is the cornerstone of treatment when treating infected nonunion. Blade plates were custom manufactured by bending 3.5- and 4.5-mm compression plates to a blade plate configuration. To lock the metaphyseal fragment to the plate, an oblique screw was placed through the lateral plate into the distal hole of the bent compression plate. The threads had an impingement fit in the screw hole which formed a triangular fixation in the metaphysis. This series was treated with adjunct fibula fixation in contrast to the prior series. Free flaps and autograft were used in some cases, but the actual number is not defined clearly. Infection was eradicated. Two of twelve did not heal with the initial attempt at reconstruction requiring a second attempt at reconstruction. Review of

Fig. 10. Summary illustration: Harvey and colleagues [3]. The use of custom contoured blade plate for periarticular nonunions. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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further articles reveals that success is not universal in the first attempt, but that secondary revisions are indicated and lead to healing. Sanders and colleagues [4] treated six nonunions of pilon fractures with GIIB open wounds (Fig. 11). This cohort represents salvage of pilon fractures with bone loss, infection, and soft tissue damage. The initial technique is an extensive de´bridement with antibiotic beads and intravenous antibiotics. Because of instability after de´bridement, a half-pin fixator is required to maintain axial alignment after de´bridement. When de´briding pilon fractures with infection, if the de´bridement of infected bone causes gross instability of the foot and ankle, a fixator is indicated to stabilize the extremity. The free flap and plate reconstruction is not placed until the wound has stabilized 5 to 6 weeks after the initial de´bridement. This is an important concept. Free flaps are not placed until the wound has been de´brided and the soft tissues resuscitated. The plafond was excised in all cases and arthrodesis was the reconstruction goal. The plate was placed anteriorly with fixation into the talus. The talar fixation screws in 3 cases were placed across the subtalar joint into the calcaneus eliminating any hindfoot motion and into the navicular in one case eliminating forefoot rotation. The authors described the severe loss of motion as a result of this salvage technique. These patients basically have a ‘‘block foot.’’ Interestingly, no patient opted for a below knee amputation, even with this stiff foot. One patient had 9 cm of shortening. This technique is not capable of reconstructing large segmental defect as bone graft reconstruction of large defects is difficult if greater than 5 cm. Gruen and Mears [5] treated five infected distal tibia nonunions with tibial calcaneal arthrodesis (Fig. 12). This cohort of infected nonunions was initially four open distal tibia fractures and one pilon fracture. The high incidence of open fracture associated with pilon fracture malunions is

Fig. 11. Summary illustration: Sanders and colleagues [4]. The salvage of open grade IIIB ankle and talus fractures. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 12. Summary illustration: Gruen and Mears [5]. Arthrodesis of the ankle and subtalar joint. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

observed throughout the literature review. The technique used here is the same as Sanders’ technique [4] initially but uses a posterior approach to fixate the tibial calcaneal arthrodesis. The free flap is not placed until the infection is debrided and the wound resuscitated. To expose the posterior calcaneus and talus, a calcaneal tuberosity osteotomy is used to mobilize the Achilles tendon and expose the posterior shaft of the tibia. The posterior approach isolated the free flap so that the fixation did not have to be placed in the damaged anterior medial soft tissue under the free flap. This reconstruction produces a ‘‘block foot.’’ Application of this technique and the prior Sander’s technique should only be considered for patients with existing subtalar joint ankylosis or synostosis. Marsh and colleagues [6] treated seven pilon fracture nonunions with a spectrum of techniques based on the environment at the nonunion site (Fig. 13). All of these cases had arthrodesis as the reconstruction goal. The plating technique uses medial and lateral plating, which requires

Fig. 13. Summary illustration: Marsh and colleagues [6]. Results of ankle arthrodesis for treatment of supramalleolar nonunion. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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separate approaches and fibula resection as compared with the blade plate fixation in the initial articles of this review. The plating technique was reserved for hypertrophic nonunions and did not use bone graft to supplement the nonunion. Half-pin external fixation using bone graft requires foot fixation with half pins. Half pins in the calcaneus, talus, and forefoot tend to loosen with time and may account for the high failure rate in this series. The concept of using external fixation for infected nonunions of pilon fractures and plating for pilon nonunions without infection is evident in this small group. Distraction histogenesis provides bone reconstruction, avoiding the use of autograft. In the two infected patients, this technique was used. The success rate, three of seven, enforces the reality that treatment of pilon nonunion can fail because of recurrent nonunion and infection. Amputation after failed salvage attempt is a reconstruction pathway that will return the patient to mobility. Functional foot scores reveal significant loss of function after salvage. Green and Roesler [7] used Hoffman external fixators to treat 11 infected nonunions of pilon fractures in 1987 (Fig. 14). This technique uses the Hoffman external fixator to stabilize the foot with a massive and heavy medial and lateral frame. Transfixation pins through the tibia, hindfoot, and forefoot produced rigid fixation and the patient could not walk in this fixator. The technique described the sparing of bone at the nonunion site so that part of the defect could be salvaged to have bone on bone contact to improve union. The authors opined that bone graft reconstruction of bone defects was difficult and the quality of bone from grafting was poor. There opinion was that amputation should be considered for infected pilon nonunions because of the poor function of the ankle and foot after salvage using this technique. The salvage rate was 56% (6 of 11). Free flaps were applied, but no accurate data were recorded. Amputation is used as secondary reconstruction in one patient. Failure to eradicate infection probably is a result of

Fig. 14. Summary illustration: Green and Roesler [7]. Salvage of the infected pilon fracture. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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inadequate initial de´bridement in an effort to preserve bone length. This article represents an external fixation method available in 1987. Zalavras and colleagues [8] treated six infected nonunions of pilon fractures with a 3-stage technique (Fig. 15). This technique represents half-pin external fixation as the fixation device for salvage of infected nonunion of pilon fracture. The treatment pathway of radical de´bridement, antibiotic beads, external fixation, and intravenous antibiotics as the initial sequence of reconstruction has been defined clearly by the prior review. The timing of soft tissue coverage always is after the infected nonunion is converted to living tissue. The cancellous autograft is not applied until the wound is viable and soft tissue coverage is complete. Shortening is tolerated in this technique as larger defects are difficult to heal with local autograft with two patients having more than 3 cm of shortening. This reflects the difficulty of using bone graft in the hostile environment of an infected pilon nonunion to reconstruct a large defect. The external fixator had to be maintained for prolonged periods of time (5–14 months) and the half pins can cause problems in talus, calcaneus and forefoot. These authors augmented the fixator with a posterior splint to reduce loosening of the half pins. The articles by Sanders, Green and Zalarvas [4,7,8] are evidence that large bone defects are difficult to reconstruct with bone graft. The problem of reconstructing bone loss associated with infected nonunion of pilon fractures was approached by Stasikelis and colleagues [9] by incorporating Ilizarov tensioned wire circular fixation and distraction histiogenesis into the reconstruction (Fig. 16). The initial sequence of the reconstruction is the same as the prior reviews. Aggressive de´bridement of necrotic bone is the essential first step. Arthrodesis is the salvage goal in all patients. Acute and delayed shortening produces viable bone on bone compression at the arthrodesis site. Alignment of the arthrodesis is facilitated by cutting square osteotomies of the plafond and dome of the talus. Because of

Fig. 15. Summary illustration: Zalavras and colleagues [8]. Infected fractures of the distal tibial metaphysis and plafond: achievement of limb salvage with free muscle flaps, bone grafting, and ankle fusion. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 16. Summary illustration: Stasikelis and colleagues [9]. Treatment of infected pilon nonunions with small pin fixators. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

the ability to grow new bone at the proximal corticotomy with distraction histiogenesis, wide excision of the infected bone is possible. Bone reconstruction is conducted in the proximal tibia far from the zone of injury. Equal leg length in five of six patients is facilitated by the ability to lengthen the proximal bone with distraction histogenesis. No local autograft is placed in the zone of injury. All of these nonunions were healed with out bone graft. There is no recurrent infection in this group of six infected pilon nonunion after reconstruction and all six had successful arthrodesis. Deformation of the transport is a complication associated with this technique. Kabata and colleagues [10] used a similar strategy using Ilizarov fixators to treat pilon nonunions in two patients (Fig. 17). This case report illustrates the Ilizarov salvage of infected nonunion of pilon fracture with a viable plafond fragment allowing preservation of the joint surface. The joint should be

Fig. 17. Summary illustration: Kabata and colleagues [10]. Reconstruction with distraction osteogenesis for juxta-articular nonunions with bone loss. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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salvaged if possible. Acute shortening is incorporated with proximal lengthening. Again, there is no need to place autograft into the zone of injury. The technique describes squaring of the plafond, but maintaining the posterior lateral spike to improve healing at the docking site. The segmental defect is closed by acute shortening. These defects are not always amendable to acute shortening. Delayed shortening or intercalary transport can be used to close the resection interval over time when the soft tissues do not tolerate acute shortening. I would recommend an addition of a foot frame to the fixator to control the foot during the lengthening to prevent equines. Cierny and colleagues [11] treated infected nonunions of ankle fractures with an aggressive de´bridement technique which excised all necrotic bone as the essential step of the treatment strategy. This reference combines 34 ankle and distal tibia fracture nonunions, but has no specific listing for infected pilon fractures. The approach of aggressive de´bridement, antibiotics and half-pin fixation external fixation was an effective technique in eradicating infection. The overall strategy and technical concepts for applying this technique are clearly defined in this article. The concept of treating infection with wide excision is an extrapolation of musculoskeletal tumor surgery. This article defined aggressive de´bridement as the initial first stage of the treatment infected nonunion of distal tibia fractures. Analysis of the reference articles (Figures 8–17) produces the following impressions: 1. Open pilon fractures are associated with subsequent nonunion and infection. 2. The initial sequence for infected nonunion of pilon fractures is extensive de´bridement, removal of hardware, and application of antibiotic beads followed by external fixation. 3. Free flaps are not applied until the wound and nonunion site are completely viable and free of necrotic tissue and infected hardware. 4. If internal fixation is used as the definitive reconstruction, bone graft of the nonunion site is required (biologics may replace autograft). 5. Distraction histiogenesis produces bone reconstruction proximal to the zone of injury and avoids the need for bone graft. 6. Preservation of the plafond is not possible in many pilon nonunion reconstructions. Arthrodesis of the ankle and subtalar joint is the reconstruction pathway for nonunions with infection and necrosis of the plafond. 7. Patients have significant loss of function after pilon nonunion reconstruction. 8. The initial attempt at reconstruction may be unsuccessful. Secondary reconstruction is indicated. Some patients may be treated better with secondary amputation. 9. There are multiple internal fixation implants used for reconstruction of pilon nonunions. The blade plate has had the widest application. (Locked plates may supplant the use of blade plates.)

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10. Half-pin external fixation with bone grafting of pilon nonunions has a significant failure rate. Circular tensioned wire fixation incorporates distraction histiogenesis as a better technique if external fixation is used as the reconstruction pathway. 11. Pilon nonunions with good soft tissue envelopes, no infection, and limited deformity and lone loss are treated with internal fixation and bone graft. 12. Pilon nonunions with poor soft tissue envelope, infection, and extensive bone loss are treated with external fixation. The literature review is presented to give readers a background for decision making when treating patients who have nonunion, malunion, and infections of pilon fractures (Figs. 8–17). The following technique guide describes the methods used when circular tensioned wire fixation is chosen as the treatment course for these difficult posttrauma problems.

Salvage technique: pilon nonunion and infection The primary event in treating a nonunion of a pilon fracture is declaring that a nonunion has occurred and that there is an infection. Many patients endure months of nontreatment because an attending physician continues to observe the fracture and use oral or intravenous antibiotics and bone stimulators. Most pilon fractures are united by 6 months. Breakdown of the wound and drainage of purulence always is a deep infection and does not resolve with antibiotic therapy. Many patients are referred with a lateral plating of the fibula and a half-pin fixator medially. There is no callus and patients have not placed weight on the foot since the injury. Review of past medical history should discover if patients have diabetes or ischemic vessel disease. Is there a history of schizophrenia or profound depression? Do patients smoke or use drugs? Do patients have immune deficiency disease? All these factors affect the ability to grow new bone with distraction histiogenesis. If patients have significant problems with these risk factors, the salvage may focus on the nonunion without an effort to use distraction histiogenesis to reconstruct bone loss and leg length discrepancy. A physical examination documents the sensation of the lateral and medial plantar nerve, calcaneal branch, superficial and deep peroneal, and sural and saphenous nerve. The dorsalis pedis and posterior tibial artery are palpated. Patients can have loss of either artery or both and the foot is surviving on the peroneal artery. The fracture site is manipulated. If there is motion, there is a nonunion in spite of how dense the bone looks on radiograph. A half-pin fixator or circular fixator is disassembled and fracture site motion is detected. Sometimes ankle motion is a pseudoarthrosis just above the ankle joint and the ankle joint has dense ankylosis in an equines position. The range of motion of the ankle, hindfoot, and forefoot is recorded.

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Flexion contractures of the toes are sequelae of pilon fractures. The condition of the soft tissues over the plafond is observed. The drainage of any fluid from the soft tissue, even if it is a small sinus, is noted and this finding alone indicates the nonunion is infected. The foot position is evaluated for equines and inversion (see Fig. 2). The forefoot can have varus and cavus deformity. Soft tissue contractures and deformities and the skeletal deformity have to be corrected or managed. The knee motion must provide a functional range of motion. If patients have a flexion contracture, their ability to walk with ankle arthrodesis is difficult. A radiograph of the foot and ankle reveals the location of the nonunion and the extent of damaged bone. The position of internal fixation devices is assessed for the surgical approaches needed to remove them. The plain film reveals the deformity of the nonunion, the condition of the joint surface, and the reconstruction pathway. If the joint surface is intact and there are 2 cm of viable bone available for reconstruction, the pilon nonunion has the possibility to be reconstructed with the ankle joint preserved. The alignment of the fibula and the assessment of a fibula plus mortise are observed. A radiograph can reveal extensive bone loss and destruction of the joint. This indicates that a salvage with arthrodesis is the pathway. A sequestrum indicates deep infection, and there may be irregular exuberant periosteal bone, which is an early involucrum. CT scans are excellent to evaluate the joint surface. The severity of the joint impaction and displacement is assessed and the plafond fragment evaluated to see if it is large enough to salvage the joint. If the joint has severe deformity and the plafond metaphysis is fragmented and displaced, arthrodesis is the reconstruction pathway. The joint surface of pilon fracture nonunions can have a near anatomic alignment with digression to gross displacement and posttraumatic arthritis. Patients who have advanced arthritic changes on radiograph can have surprising function. If possible, salvage the joint. Years after reconstruction, conversion to arthrodesis or joint arthroplasty is indicated if pain produces disability. Bone scans and MRIs are difficult to interpret at a nonunion site. The T2 image shows water signal diffusely throughout the zone of injury with nonunion and infection. An erythrocyte sedimentation rate and C-reactive protein evaluation as an isolated value is not reliable evidence of infection. Serial escalating values over time can indicate an expanding infection. Patients who have draining abscess and extensive edema and inflammation require urgent de´bridement. Patients who do not have infection and who have nonunions with callus at the fracture site should undergo rehabilitation of the foot and ankle before starting the reconstruction. The half-pin fixator spanning the ankle is removed in clinic. Some half pins are infected and need local de´bridement. Lysis of bone in a conical pattern adjacent to the half pin indicates infection. Under anesthesia, the half pin is removed and the granulation tissue curetted at the infection site. The pin is lavaged with low-pressure saline. The granulation tissue is cultured and antibiotics are given intravenously for 7 to 14 days. A clean pin site is healed over

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in 2 weeks. Continued drainage indicates continued infection. Reconstruction is not started until prior pin tracks are healed. Patients are encouraged to walk in a fracture boot or cast. Therapy is prescribed to mobilize the toes and forefoot. The foot has local modalities and is desensitized. Several months of prereconstruction therapy can transform a hypersensitive foot in cavus and varus with flexion contractures of the toes into a soft nontender foot that is able to transfer weight. If possible, the foot should be rehabilitated before starting the reconstruction. During this period of time, a surgeon evaluates the psychologic stability of patients and determines if they are candidates to have a circular fixator on their leg for a prolonged period of time. Patients who continue drug, tobacco, and alcohol abuse; do not participate in therapy; or are sociopaths are poor candidates for circular fixation. There is a subgroup of pilon nonunions that can be treated with distraction of a hypertrophic nonunion [2]. This technique is based on the Ilizarov principle that a hypertrophic nonunion can be united with distraction and angular correction (Figs. 18 and 19). The method is applicable to nonunions, which were treated by blade plates and bone graft in the reference review [3–11]. The nonunion is located at the metaphysis with hypertrophic callus. The most common pattern occurs when a low energy pilon fracture is treated with fibula plating and bridging external fixation. With frame removal, the fracture collapses into varus or apex posterior deformity (see Fig. 4) and patients walk in a cast or brace. A large callus develops as the angulation

Fig. 18. A varus collapse hypertrophic nonunion can be treated with bone grafting and blade plate fixation. The alternative is to use angular distraction of the nonunion placing a hinge at the center of rotation. The frame consists of a double-ring fixation block with two AP half pins and a medial pin. The plafond fixation block has opposed olive wires in the 60 safe zone. The hinge is placed 90 to the plane of deformity (usually varus) at the apex of the fracture. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 19. An alternative and more dynamic method is to use a Taylor Spatial Frame, which has the advantage of secondary ‘‘tweaking correction’’ to align the nonunion anatomically. An osteotomy of the fibula improves the ability to align the nonunion. (Courtesy of Lignum Designs/ J. Hutson MD, Coral Gables, FL; with permission.)

of the malunion progresses. The fibula plate eventually may deform or break. There may be damaged skin on the medial ankle from the initial GIII open fracture. The nonunion becomes stiff and patients can walk almost full weight. The joint surface has a good or excellent reduction. These patients usually are encountered 6 months to 12 months after injury. Distraction of hypertrophic nonunion technique The fibula plate is removed. If the fibula has healed in malunion, an osteotomy is created at the apex of the deformity obliquely (Fig. 20A–H). The oblique osteotomy allows the distal malleolus to be reduced as the tibia is distracted into position. If the tibia nonunion is stiff and early malunion is possible, an osteotomy with osteotomes is accomplished at the center of rotation. An alternative technique is to complete and osteotomy with a Gigli’s saw. A midtibial fixation block is secured with two anterioposterior (AP), 6-mm half pins and a medial lateral (ML) half pin (see Fig. 20E). If using the Ilizarov system, the plane of deformity is analyzed. The hinges are placed so that opening the hinge corrects angular alignment and lengthens the nonunion site. The ring over the plafond is placed orthogonal to the distal plafond fragment. Three opposed olive wires are placed in the 60 divergent safe zone (Figs. 21 and 22). If the fragment is large enough, an AP half pin is placed in the trabecular bone. Hydroxyapatite pins are recommended for improved bone fixation. The Taylor Spatial Frame (Smith & Nephew) is an effective device for this technique. The Taylor Spatial Frame has the ability to correct muliplanar deformity and lengthen in a continuous

Fig. 20. Clinical example of angular distraction of hypertrophic nonunion. (A, B) Varus collapse of pilon fracture with limited internal fixation of plafond joint surface. Fixation of the fibula without axial fixation of the tibia results in this nonunion pattern. (C) Fixation with Taylor Spatial Frame. Washer on medial olive wire prevents migration of the olive into the soft metaphyseal bone. (D) Slow distraction of nonunion corrects alignment with new bone formation at nonunion site. (E) The patient is able to walk on the Taylor Spatial Frame during correction of nonunion. (F, G) Corrected alignment of plafond nonunion. Posttraumatic arthritis of joint surface is observed with eburnation of subchondral bone. (H) Alignment of heel post reconstruction.

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Fig. 21. (A) Safe wire pathways of the distal plafond fixation block. The wire cluster has a horizontal reference wire, posterior medial olive, and a fibula wire. The posterior fragment is fixated if needed with a wire passed between the peroneal and Achilles tendon. (B) The ankle joint capsule extends approximately 1 cm at the superior anterior lateral plafond. Place the horizontal reference wire 12 mm above the joint. A medial malleolus wire can be placed in the coronal plane. (From Vora AM, Haddad SL, Kadakia A, et al. Extra capsular placement of distal tibial transfixation wires. J Bone Joint Surg 2004;86A:988–93; with permission.)

distraction. The deformity parameters are analyzed and a gradual correction is calculated using Web-based software. The cortex on the concave side of the deformity (opposite the apex) is lengthened 0.5 mm a day (three connecting rod adjustments: morning, midday, and afternoon) until the nonunion is distracted and out to length. If Ilizarov angular correction is used, the nonunion site is distracted 0.25 mm twice a day until completion of the correction. Patients are encouraged to walk on the extremity as tolerated until the nonunion is united. The frame is removed when the distracted bone has developed clearly defined cortical margins and there is dense new bone throughout the distraction. The reconstruction is approximately 6 months or longer after initiation of the distraction. The frame is removed in clinic or under anesthesia. Patients walk 50% weight in a cast for 2 weeks, then progress to full activity in 6 to 12 months.

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Fig. 22. Larger metaphyseal fragments have olive wires placed across both sides of the ring to balance the distorting forces of the tensioned wires. Salvage of minimal plafond joint fragments requires that the wires are placed on the inferior side of the ring on washers for clearance. A crossing wire from one side to the opposite side allows the third wire placement. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

Fig. 23. Metaphyseal reconstruction with acute shortening. Necrotic bone and fibrous nonunion tissue are excised. Squaring osteotomies are completed through bleeding bone. Partial excision of fibula as needed. The frame consists of a single- or double-ring fixation block with three to four half pins. The metaphyseal fixation is 3 to 4 divergent olive wires. The frame is converted to bifocal configuration by adding proximal corticotomy with 5/8-full ring block. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 24. Arthrodesis acute shortening reconstruction. The necrotic plafond is excised. Squaring osteotomies dome of talus and tibia are completed. A double-ring tibia fixation block and foot fixation are compressed after acute shortening. The tibia is lengthened proximally in patients who are candidates for distraction osteogenesis. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

The distraction technique avoids bone graft and hardware in the zone of injury and allows weight bearing throughout the treatment course. It is valuable especially in patients who have pilon nonunion and who have damaged skin medially. Plating could lead to skin slough, infection, and secondary free flap. Wire infection is a complication that is treated with local pin care and antibiotics. Six nonunions have been treated with this technique. All were united with axial alignment without complication. Reconstruction with excision of nonunion and infection The initial surgery in the salvage of pilon fractures is the exploratory de´bridement. The goal of the de´bridement is to identify which bone is viable and excise all necrotic tissue and dense local fibrocartilagenous tissue and remove all hardware in the nonunion site. For 2 weeks before the de´bridement, no oral or intravenous antibiotics are given. Obtaining an accurate culture of the infecting bacteria is essential. The exception to this rule is patients who have an expanding abscess, which requires urgent de´bridement. The extremity is elevated for 3 minutes and a tourniquet is used on the thigh. The consistency and color of the bone is an indication of the vascularity. Without the tourniquet inflated, the blood in the field obscures the appearance of the nonunion site. The tibia plafond is de´brided through an anterior medial or medial approach. Occasionally, an anterior lateral approach is used if there is infected hardware placed at the fracture reduction on the lateral tibia. If there is a free flap over the nonunion, the flap is elevated from distal to proximal avoiding the pedicle of the flap. The interval

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Fig. 25. (A, B) An intercalary transport frame with transport to close segmental defect. There is shortening of the extremity from the initial treatment and the fibula has healed with side-to-side callus. (B) After intercalary transport, the defect is closed but the leg is short. (C, D) The fixator is converted from intercalary transport to bifocal lengthening/compression. After completion of intercalary transport distally, the long threaded rods connecting the 5/8-full ring to the distal plafond fixation are removed one at a time. Short threaded rods are place across the compression of the osteotomies and distraction clickers are placed proximally to lengthen the tibia. The fibula requires and osteotomy to allow lengthening. The fibula malunion is not taken down. (D) The tibia is lengthened until the leg length is equal. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 26. Delayed shortening of arthrodesis. The foot fixation block is shortened slowly, 1 mm 4 times a day, until the arthrodesis site is compressed. The soft tissues must be observed and the rate of shortening titrated to protect the soft tissue from sloughing. Proximal lengthening reconstructs leg length inequality. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

between the flap muscle and underlying soft tissue is dissected with tenotomy scissors exposing the underlying nonunion. The dense fibrous tissue is removed by sharp dissection and pituitary ronguers. Plates are removed locally and small excisions are used proximally away from the nonunion site to remove screws. Necrotic fragments of bone are removed. Necrotic bone has a gray yellow appearance and sometimes an olive green color. Necrotic bone is brittle and broken away easily with ronguers and osteotomes. Viable cortical bone is pink white with punctate bleeding. Viable bone is resilient and does not chip away easily. Deep cultures are obtained in areas of the nonunion, which have free fluid and purulence. In 21 infected pilon nonunions treated by the author, the infection organisms were Staphylococcus aureus, methicillin-resistant S aureus, S epidermis, Pseudomonas, Bacteroides, Escherichia coli, Acintobacter, Enterobactor cloacae, Enterococcus faecalis, and Streptococcus gamma. This group of gram-positive and -negative bacteria demands that the initial postde´bridement antibiotics have wide coverage until the infecting organism is identified. After the initial de´bridement of necrotic bone and fibrous tissue, the tourniquet is released and the bone inspected. Viable bone has punctate bleeding

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Fig. 27. Metaphyseal reconstruction with intercalary transport frame. The frame consists of a 5/8-full ring proximal fixation block, single transport ring with two AP half pins, and medial half-pin and plafond fixation block. The threaded rods connect the proximal and distal fixation blocks and the transport ring is moved distally 0.25 mm twice a day. Better results are achieved with squaring osteotomies in bleeding bone compared with compression of the nonunion. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

points. The bone is lightly scaled with a sharp osteotome removing thin wafers. Dead bone has no bleeding. Ronguer and osteotome bone removal continues until bleeding bone is encountered. A high-speed rotary burr must be lavaged in iced saline to prevent heat damage if this tool is used. The trabecular bone has bleeding and a firm consistency. It can be difficult to determine viability of the fatty trabecular bone, but bleeding is the key to

Fig. 28. Metaphyseal reconstruction with intercalary transport. The segmental bone loss is reconstructed with proximal bone transport. Large segmental bone loss requires docking site revision before docking. The footplate is opinional depending on the fixation of the plafond and contractures of the tendons crossing the joint. The frame is comprised of 5/8-full ring block, single transport ring block, plafond fixation block, and opinional foot fixation with opposed calcaneal olive wires. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 29. Arthrodesis reconstruction with intercalary bone transport. The docking site requires revision before compression. The frame is comprised of 5/8-full ring block, single transport ring block, and foot fixation block. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

the demarcation. The extent of dead bone can surprise surgeons. The entire plafond can be necrotic with shattered fragments crushed down into the talus. The cartilage is not excised from the talar dome until the reconstruction phase. The medial malleolus has blood supply from the deltoid ligament and may be the only bone of the plafond still viable. The bone is removed in

Fig. 30. The 5/8-full ring fixation has four fixation components: a horizontal reference wire aligned in 3 to 5 varus (the wire is placed 90 to the axis of the shaft, not parallel to the plateau joint), fibula head wire, posterior medial wire, and AP half pin on medial side tibial tubercle. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

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Fig. 31. A single-ring transport ring has two AP half pins and a medial pin. The pin spread is increased by using three- and four-hole Rancho cubes. The initial cube is placed using a universal hinge. If the Taylor Spatial Frame is used, these half pins have to be placed to avoid the connecting struts which angle across the axis of the shaft to connect with the tabs. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

small fragments carefully working through the substance until bleeding is found. It is essential to excise all of the dead bone, as successful reconstruction is based on the biologic principle of viable bone uniting with callus. The fibula rarely is involved in the nonunion site. The fixation is not removed at this juncture. The fibula serves as a lateral strut and provides stability to the de´brided tibia and foot. If the fibula is removed, a temporary half-pin fixator is required. The de´brided nonunion site is lavaged copiously with normal saline and further devitalized soft tissue trimmed away. There is punctate bleeding throughout the wound with soft tissue and bone bleeding. If there is no infection, an Ilizarov reconstruction can be completed after de´bridement. An infected nonunion may need second and third de´bridements. The segmental bone defect is filled with 0.25-inch–diameter antibiotic beads. The beads are manufactured with 20-g methymethracrylate, 2.4-g tobramycin, and 1.0-g vancomycin. The wound is closed with nylon vertical mattress sutures. The leg is splinted with a bulky absorbent dressing. A second de´bridement is scheduled 2 to 3 days after the initial de´bridement. Further bone and tissue is removed as needed. Intravenous antibiotics are adjusted to the culture result. When the infected nonunion has clean bleeding tissue at the last de´bridement and has had 1 week of intravenous antibiotics, the distal leg is ready for reconstruction. The de´brided nonunion site is analyzed. The major decision point is to decide if there is enough remaining plafond to salvage the joint. There must be at least 2 centimeters of plafond metaphysis intact for there to be space for three tensioned wires to fixate the joint fragment (see Figs. 21

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Fig. 32. Universal cube half-pin fixation. A fixation cube is secured to a long hinge or two- or three-hole post with a bolt and star washer. The half pin to ring alignment can be adjusted to align the ring block orthogonally or to place half pins at varying angles to the shaft of the tibia. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

and 22). If the plafond fragment does not meet these criteria, salvage to ankle arthrodesis is the reconstruction pathway. The proximal and distal ends of the nonunion have irregular fragment patterns. The bone ends are squared with a micro-oscillating saw bathed in iced normal saline. Small metacarpal retractors are used to protect the soft tissue during the osteotomy. The posterior cortex is cut until there are 2 to 3 mm of bone and the fragments are snapped off. Do not allow the oscillating saw to cut the posterior and anterior tibial arteries. The osteotomies are completed with as little soft tissue elevations as possible. The squaring osteotomies enforce the reduction. When the circular fixation system compresses the squared bone ends, the alignment is axial. The dome of the talus is squared if an arthrodesis is chosen. All of the cartilage on the talar body is removed. With the osteotomies completed, the final decision on

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Fig. 33. The double-ring fixation block has two AP half pins and one or two medial half pins. This fixation block can be modified to have a reference wire distally above the tibial metaphysis. The AP half pins are mounted on universal cubes to align the fixation block orthogonally. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

the technical pathway is decided. The reconstruction is joint salvage or arthrodesis. The segmental bone loss is closed with acute/delayed shortening or with intercalary bone transport (Figs. 23 and 24). For large segmental defects, the defect can be reduced by acute shortening and the remaining defect closed by intercalary transport. Leg length inequality is reconstructed with proximal lengthening (Fig. 25A–D). The essence of the technique is that living bone is compressed at the nonunion/arthrodesis site and new bone is created proximally in the tibia with normal soft tissue and a rich blood supply. This is contrasted with the plating technique of placing a massive

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Fig. 34. The foot fixation block. Two opposed olive wires are placed in calcaneus. The wire pathways avoid the posterior tibial nerve and artery. Talar neck and body olive wires are placed. The footplate requires closure with a ring or rod anteriorly. The footplate is stacked for large feet. The talar wires are placed on post on single ring for small feet. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

necrotic bone graft in the zone of injury with damaged blood supply. Acute shortening aligns and compresses the osteotomies of the tibia shaft with the plafond or talar dome. A fibula resection is required if the fibula is intact. An oblique osteotomy is compressed as the first step. If the fibula impedes the acute shortening, small segments are excised until the tibial osteotomy can be compressed. The fibula resection usually is half of the acute shortening distance. The surgical approach for the tibia de´bridement must be closed before acute shortening. Shortening the cylindric soft tissues of the ankle causes the tissues to bulge circumferentially and kink the blood vessels. Patients tolerate 3 cm of shortening, but some patients who have flaps and dense fibrosis of the skin may not be able to tolerate this amount. The pulses are monitored as the docking site is compressed. A pulse Doppler is used. The pulse starts to fade as the shortening progresses. The shortening is halted at this point. If there still is a gap, then the technique of delayed shortening is used (Fig. 26). The docking site is compressed 1 mm 4 times a day until the docking site is compressed. Sometimes there is a mild slough of the skin edges of the incision, which heals by secondary intention. The alternative method of closing the segmental defect is intercalary transport (Figs. 27–29). Intercalary transport avoids the shortening of the soft tissues at the nonunion. The technique is used when the segmental bone loss is greater than 3 cm or in patients who cannot tolerate acute

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Fig. 35. The navicular curves around the head of the talus. The talar neck wire is placed posteriorly in the neck to avoid impaling the talar navicular joint. The talar neck wire is placed medial to lateral and talar body wire placed lateral to medial. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

shortening. The technique is more difficult than acute shortening. The bone ends have to be aligned anatomically with a large gap between them. A proximal corticotomy opens as the tibial shaft fragment is transported distally through the soft tissues. The intercalary transport is to docking at the metaphysis or docking to arthrodesis at the talus. The distraction rate in adults is 0.5 mm per day (0.25 mm twice a day). Smaller defects are aligned easily and compressed within several months. Larger defects require a long period of distraction and have cortical end capping of the tibia by the time the transported segment converges on the plafond or talus. A docking site revision is necessary. The bone of the tibia and metaphysis/talus is de´brided to bleeding bone and new squaring osteotomies may be necessary. A bone graft is not needed when two bleeding surfaces are compressed. Some surgeons augment the docking site with bone graft. There can be soft tissue invagination at the docking site, which is treated with careful elevation and local rotation flaps.

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Fig. 36. Clinical example metaphyseal reconstruction acute shortening/proximal lengthening bifocal frame. (A, B) Nonunion of C2.3 pilon fracture. (C) De´bridement of nonunion tissue and osteoconductive biologic material leaves irregular bone contour. The initial de´bridement removes the hardware and obviously nonviable tissue with the tourniquet inflated. (D) Squaring osteotomies and punctate bleeding in bone and soft tissue. (E) Bifocal frame with acute shortening of tibia and fibula and proximal corticotomy. Distally, a small section of fibula was removed to facilitate shortening. (F) The frame is constructed of four fixation blocks: proximal 5/8-full ring, midtibia double ring with three half pins and wire, distal plafond ring with three olive wires, and foot plate to control to prevent equines during lengthening. (G) Mature 4-cm lengthening with clearly defined medial and lateral neocortex. (H) Healed osteotomy site distally. The footplate was removed after lengthening to allow ankle/hindfoot motion. The olive wire in the midtibia fixation block also has been removed as healing progressed. (I, J) Reconstructed pilon nonunion with lengthening of the tibia and fibula and healed distal tibia squaring osteotomy. Patient returned to work as auto mechanic.

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Infected nonunions have skin sloughs and draining sinus. After de´bridement, there is a defect of several centimeters. Intercalary transport brings soft tissue into the defect as the bone is transported distally. The open wound closes by secondary intention as the living bone fills the defect. During the transport, bloody drainage occurs as the bone fills the defect pushing the hematoma out through the defect. The ability to close the skin defect by transport avoids free-flap reconstruction, which is common to plate and bone graft reconstruction. Leg length inequality after acute shortening or intercalary transport is reconstructed with distraction histiogenesis at the proximal corticotomy site. An acute shortening fixator has distraction connecting rods placed proximally to regain length and intercalary transport frame is revised to a bifocal distal compression proximal lengthening frame (see Fig. 25A–D). Circular fixator application

:

Application of a circular fixator is simplified by incorporating the concept of fixation blocks into the design of the frame. All of the construction fixators are combinations of basic fixation blocks. The proximal metaphyseal tibia superior to the corticotomy site is fixated by a 5/8-full ring fixation block (Fig. 30). The proximal open rings allow patients to flex their knee to 100 . There are three tensioned wires and one AP half pin. The midtibia shaft is fixated by two configurations of fixation. The first is a single ring, which is used for intercalary transport (Fig. 31). The ring has two 6-mm half pins in the AP plane and a ML half pin. If the Taylor Spatial Frame system is used, the half pins have to clear the connecting struts, which are angling across the frame and tibia from one tab to the next. The pins are placed in universal cubes to align the ring orthogonally and provide angular alignment of the pins (Fig. 32).

Fig. 37. Clinical example of intercalary transport toarthrodesis. (A) Ten-year chronically draining nonunion of pilon fracture treated with internal fixation. (B) Removal of hardware and excision of 7-cm infected metaphysis. Free-flap soft tissue reconstruction over antibiotic spacer. (C) The intercalary transport frame consists of three fixation blocks: proximal 5/8-full ring, midtibia transport ring with three half pins, and foot fixation with double-ring fixation with opposed olive wires in the calcaneus and talar neck wire. The transport has been completed with the tibia ring in a distal location. The proximal carbon fiber ring is a stabilization ring used to stiffen the frame for long tibias. (D) The free flap has been compressed by the intercalary transport and has a bulbous contour. The nuts are loosened and taped between the tibia ring and foot fixation as a trial of the arthrodesis before frame removal. (E, F) Anterior and lateral radiograph of ankle arthrodesis. Observe osteophyte present at talar navicular joint 6 years after reconstruction. (G, H) Reconstructed tibia with mature proximal transport. The patient returned to work full time as a salesman. (I, J) Reconstructed extremity.

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If a simple compression frame at the nonunion site is used or if a bifocal proximal lengthening/distal distraction frame is applied, a two-ring stable base with two AP half pins and a ML pin is constructed (Fig. 33). A second ML pin is placed for large patients. The plafond is fixated with a single ring with three to four olive wires (see Figs. 21 and 22). An AP half pin placed anterior medial avoiding the anterior tibial tendon adds stability in the AP plane if the distal metaphyseal fragment is large enough. This configuration often is used when the nonunion is at the junction of the shaft and metaphysis in a C2.3 pilon. Foot and ankle fixation is constructed with three configurations (Fig. 34). The first is a calcaneus stabilization to keep the foot in plantar neutral during reconstruction. This is configured with two opposed olive wires in the calcaneus. This fixation is used when there is going to be lengthening of the tibia when the leg has been shortened for many months. The foot frame prevents the foot from deforming into equines when the tibia is lengthened. The posterior tibial tendon is stretched by foot therapy as the lengthening progresses. The gastronemius soleus is stretched by the fixed calcaneus. The other use of this foot fixation is to stabilize a borderline plafond joint fragment. If the plafond fixation is marginal (see Fig. 22), a single or double wire is placed and the calcaneus is fixated. Once the metaphyseal docking site is healed with early callus, the foot plate is removed and a third wire is placed to promote weight-bearing and motion therapy of the ankle and hindfoot. The footplate has an increased level of fixation when the plafond has been excised and arthrodesis is the reconstruction path. Two opposed olive wires are placed into the neck and body of the talus (Fig. 35). The talus wires are placed on three- and four- hole post, which are deformed by the wire tension. This foot frame configuration is used for small feet. The foot frame is modified by using two long foot rings separated by 3-cm hexagonal sockets or threaded rods. The foot fixation blocks need to have the anterior open end closed with a half ring or heavy bar to keep the footplate from warping with tensioning of the wires. The double footplate can be distracted to offload the subtalar joint to reduce the incidence of ankylosis of the joint. This is accomplished by using threaded rods between the footplates. The footplates are distracted 5 mm after the calcaneal and talar wires are tensioned.

Technical sequence of frame construction The sequence of frame construction always starts with the tibial fixation followed by alignment of the docking site of the nonunion or arthrodesis. The sequence of the frame configuration is detailed for each configuration. Compression metaphyseal nonunion 1. Apply double-ring fixation block to the tibia in orthogonal position. 2. Place horizontal reference wire in plafond.

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3. Manipulate plafond fragment on ring until acute shortening aligned. 4. Add pins and wires to stiffen frame. 5. Compress nonunion between the fixation blocks. Compression arthrodesis 1. Apply double-ring fixation block to tibia orthogonal position. 2. Place horizontal reference wire in calcaneus. 3. Manipulate hindfoot until arthrodesis aligned. Tension reference wire on distal footplate. Secure the horizontal reference wire with fixation bolts and apply 110 kg tension. 4. Place opposed olive wires into talus on proximal footplate. 5. Add pins and wires to stiffen frame. 6. Compress arthrodesis. Bifocal proximal lengthening and distal compression clinical example 1. Assemble the 5/8-full ring fixation block to the midtibial fixation block with distraction clickers or Taylor Spatial connecting rods (Fig. 36A–J). 2. Place horizontal reference wire 12 mm below joint in 3 to 5 varus to align assembled frame orthogonally. 3. Align the frame orthogonally and place AP half pin on distal ring of midtibia fixation block. Use a universal Rancho cube on the half pin to adjust the frame until it is aligned orthogonally. 4. Align and compress the nonunion docking site or arthrodesis distally by adding metaphyseal ring or footplate fixation. 5. Add pins and wire to midtibia and proximal tibia fixation block. 6. Complete corticotomy. (Some surgeons complete the corticotomy with a Gigli’s saw before placing the fixation blocks.) If the lateral malleolus is intact, a fibula corticotomy is completed to allow fibula lengthening. Intercalary transport frame (the most difficult configuration) 1. Assemble 5/8-full ring to a single stainless steel midtibia transport ring. If using the Ilizarov system, connect the two fixation blocks with long threaded rods, which extend to the level of the plafond or foot fixation. If using Taylor Spatial Frame, connect the 2/3-full ring to the midtibia ring with connection struts and connect the transport wing to the metaphyseal or arthrodesis foot plate (clinical example, Fig. 37A–I). 2. Align the proximal and midtibia ring orthogonal on the tibia. 3. Place temporary rods over the tibia in the AP and lateral fluoroscopic view. The proximal tibia should be aligned. Place the horizontal reference wire in the plafond or calcaneus and manipulate the position of the distal bone block until the plafond or talus is centered on the alignment rod on the AP and lateral fluoroscopic image. Precision in alignment facilitates docking later on. Place temporary threaded rods on

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the frame and use these on AP and lateral fluoroscopic views to align the tibia orthogonal. The rods are placed through the ring holes without nuts and can be moved as needed. The posterior cortex of the tibia is parallel to the rod. The anterior cortex is curved. 4. Add pins and wires to the fixator to increase stiffness. 5. Complete corticotomy. Management reconstruction Compression frames for nonunion and arthrodesis are maintained for 6 months or longer. X-ray evaluation must reveal definite callus across the osteotomy site. If the docking site is not healed by 6 months, a revision osteotomy is completed. Patients are encouraged to place weight as tolerated using crutches during fixation. Cyclic weight bearing stimulates union. Before frame removal, the frame is loosened. There should be solid union. Motion indicates nonunion. After frame removal, patients walk 50% weight for 2 weeks. Radiograph out of the cast and frame clearly reveals extent of the callus across the nonunion or arthrodesis. Activity is increased as tolerated until mature healing approximately 1 year after frame removal. The length of bone transport directly effects the frame time for reconstructions incorporating distraction histiogenesis. The distraction index ranges from 1.2 months per centimeter to 2.5 months per centimeter. Reconstructions of large defects have frame times longer than a year. Weight bearing on the frame and Exogen (Smith & Nephew) bone stimulation improve the maturation of the bone transport and reduce frame time. The tibia is transported distally in intercalary transport. The distal end works through the tissue and docks with the metaphysis or talus. After long transports, a docking site revision is indicated to freshen the docking surfaces and correct soft tissue invaginations. During this transport, open wounds distally heal by soft tissue mobilization and secondary intention. The docking site requires 6 months or more of fixation before union. The distal docking site or arthrodesis may unite many months before the transport matures. The distal fixation block can be removed leaving a proximal frame supporting the transport. The transport must have three developed cortices (lateral, posterior, and medial) before frame removal. The sequence of removal is first to neutralize the distraction clickers or struts. This is accomplished by loosening the rods and allowing the distraction between the rings to fall back. The distraction connecting rods are tightened in this relaxed position. If there is no collapse of the transport after 2 to 4 weeks, the rods are loosened and taped in place for an additional 2 weeks. After neutralization, cortical edge fractures may appear. This indicates that more time is needed before frame removal. The frame is not distracted again. Frame removal follows 2 weeks later. The pins and wires have varying levels of inflammation and infection. The skin is under the most tress during the transport phase and improves during maturation. Meticulous pin and wire care reduces the level of

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Fig. 38. Graphic summary of 51 pilon fracture nonunions. Three internal fixations with bone graft. Six distractions of hypertrophic nonunions. Twenty-two metaphyseal plafond reconstructions and 20 arthrodesis reconstructions. Eighteen nonunions had acute shortening and 32 nonunions had bone transport to reconstruct bone loss. (Courtesy of Lignum Designs/J. Hutson MD, Coral Gables, FL; with permission.)

infection. Oral antibiotics (trimethoprim sulfamethoxazole or doxycycline/ rifampin) are used whenever a wire has inflammation. Wire and pin infections are treated with a 7-day course of vancomycin. The pin or wire is removed if infection persists. Outcome The outcome provides patients with a reconstructed extremity with reduced function. In the author’s series of 51 pilon nonunions, the foot ankle score ranges from 42 to 92 with a mean of 71 (Fig. 38). Posttraumatic arthritis of the ankle, hindfoot, and midfoot joints progresses with time causing a slow deterioration in foot function. There has been no recurrence of infection of the 21 patients who had infected nonunion. This reflects the aggressive de´bridement that is supported by the advantage of bone transport. References [1] Chin KR, Nagarkatti DG, Miranda MA, et al. Salvage to the distal tibia metaphyseal nonunions with 90 degrees cannulated blade plate. Clin Orthop Relat Res 2003;409:241–9. [2] Reed LK, Mormino MA. Functional outcome after blade reconstruction of distal tibia metaphyseal nonunions: a study of 11 cases. J Orthop Trauma 2004;18(2):81–6.

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[3] Harvey EJ, Henley MB, Swiontkowski MF, et al. Benirschke. The use of custom contoured blade plate for periarticular nonunions. Injury 2003;34(2):111–6. [4] Sanders R, Pappas J, Mast J, et al. The salvage of open grade IIIB ankle and talus fractures. J Orthop Trauma 1992;6(2):201–8. [5] Gruen GS, Mears DC. Arthrodesis of the ankle and subtalar joint. Clin Orthop Relat Res 1991;268:15–20. [6] Marsh JL, Rattay RE, Dulaney T. Results of ankle arthrodesis for treatment of supramalleoloar nonunion. Foot Ankle Int 1997;18:138–43. [7] Green SA, Roesler S. Salvage of the infected pilon fracture. Techniques in Orthopedics 1987; 2(3):37–41. [8] Zalavras CG, Patzakis MJ, Thordarson DB, et al. Infected fractures of the distal tibial metaphysis and plafond: achievement of limb salvage with free muscle flaps, bone grafting, and ankle fusion. Clin Orthop Relat Res 2004;427:57–62. [9] Stasikelis P, Calhoun J, Ledbetter B, et al. Treatment of infected pilon nonunions with small pin fixators. Foot Ankle 1993;14:373–9. [10] Kabata T, Tsuchiya H, Sakurakichi K, et al. Reconstruction with distraction osteogenesis for juxta-articular nonunions with bone loss. J Trauma 2005;58(6):1213–22. [11] Cierny G, Cook WG, Mader JT. Ankle arthrodesis in the presence of ongoing sepsis: indications methods, and results. Orthop Clin North Am 1989;20(4):709–21.