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Journal of the American Academy of Orthopaedic Surgeons 8 We are accustomed to thinking of foot and ankle fractures in the patient with diabetes as ÒCharcot injuries.Ó Although this terminolo- gy does describe a disease process, it is now of historic interest only; the term ÒneuroarthropathyÓ more correctly describes the rapid onset of painless and severe joint destruction. This disease process was dis- cussed by Charcot in 1868 with ref- erence to a patient with locomotor ataxia and posterior column dys- function of the spinal cord (tabes dorsalis). 1 In 1936, Jordon was the first to associate diabetes with neuroarthropathy. 2 Fractures and dislocations are part of the spectrum of this arthropathy, which has a var- ied presentation. The sine qua non of neuroarthropathy is architectural disruption and disorganization of the foot either in the absence of pain or without an appropriate level of pain. 2 In the 19th century, syphilis was a common cause of this form of arthropathy. Today, although the major cause of neuroarthropathy worldwide is leprosy, most patients with neuroarthropathy in the United States have diabetes. Other causes include alcohol-induced peripheral neuropathy, syringo- myelia, and congenital indifference to pain. In diabetic patients, the incidence of neuropathy is high (30% to 50%), 3 but neuropathic fractures occur less commonly, with an incidence of only 1.0% to 2.5%. 2,4 Typically, neuroarthropathy occurs in patients who have had diabetes for 10 years or more, and the incidence of this condition rises with the duration of diabetes. 2,5,6 On rare occasions, however, neuroarthropathy coexists with the first presentation of diabetes mellitus. 2 Interestingly, neuroarthropathy in the contralateral foot occurs at a higher frequency (approximating 30%) than in the initially involved foot. 2 Whether this increased propensity repre- sents a predisposition to the development of neuroarthropathy or is a result of increased load bearing in the uninvolved foot is not under- stood. 7 In diabetic patients with renal disease, not only the incidence but also the morbidity of neuroarthropathy increases dra- matically. 4,8 Pathophysiology In the early stages of neuroarthropathy, cartilaginous fibrillation and narrowing with subchondral and endochondral bone formation occur in the affected joint. In later stages, the destructive changes are marked at the points of contact between the two articular surfaces, Dr. Myerson is Director, Foot and Ankle Service, Department of Orthopaedic Surgery, Union Memorial Hospital, Baltimore. Dr. Edwards was a Fellow, Department of Orthopaedic Surgery, Union Memorial Hospital. Reprint requests: Dr. Myerson, Union Memorial Hospital, Johnston Professional Building No. 400, 3333 N. Calvert Street, Baltimore, MD 21218. Copyright 1999 by the American Academy of Orthopaedic Surgeons. Abstract Neuroarthropathy, a rapid, painless destructive process, has become increasingly prevalent among long-lived diabetic patients. It is characterized by warm, swollen joints with a grossly disorganized radiographic appearance, in spite of which the patient is often pain-free. Neglect of this condition results in progressive deformity or instability, often complicated by ulceration and infection, which can ultimately result in loss of independent mobility, loss of the affected limb, and even death. In most cases, a plantigrade, stable, and functional foot can be achieved with simple nonoperative techniques, such as the use of a total- contact cast or shoe modification. A few patients in whom uncontrolled instability or major osseous prominences cause recurrent ulceration will require reconstructive surgery (either exostectomy or osteotomy/arthrodesis). Although some patients will have an improvement in function, ongoing vigilance is necessary. J Am Acad Orthop Surg 1999;7:8-18 Management of Neuropathic Fractures in the Foot and Ankle Mark S. Myerson, MD, and William H. B. Edwards, MB, BS, MS, FRACS Mark S. Myerson, MD, and William H. B. Edwards, MB, BS, MS, FRACS Vol 7, No 1, January/February 1999 9 resulting in fragmentation of articular cartilage, destruction of ligaments, eburnation, and bone ab- sorption. Massive osteophytes, loose bodies, and often periosteal bone are formed. The joint capsule and synovium become thickened and edematous, initially with vascular spaces but later with fibrous tissue. Microscopic bone debris and cartilage in the capsule are considered by some to be pathog- nomonic of the process. 9 Limited sensation combined with active use (but not necessarily over- activity) is required for a neuropathic fracture to develop. 2,10,11 For example, neuroarthropathy is seen only in active patients with neuropathy, but not in inactive patients with neuropathy (e.g., patients with spinal injuries). Although neuroarthropathy seems to develop after cumulative stress to the foot, it can occur after a single episode of acute trauma. Patients with neuroarthropathy have satisfactory (but not normal) circulation to the foot; Doppler indices are typically greater than 0.6 in most patients. 4,12 It is likely that perfusion of the foot is in some way related to this disease process, which may be associated with autosympathectomy, 13 producing increased blood flow and bone resorption. The initial radiographic change in acute neuroarthropathy is usually a fracture associated with joint subluxation. This sequence is not always present, and gross deformity may develop in the absence of a fracture, particularly in the midfoot. This is clearly a stress-related or overuse phenomenon in which ligamentous failure occurs before fracture. Altered collagen cross- linking, because of either diabetes 14,15 or autosympathectomy, makes ligaments brittle, inelastic, and susceptible to trauma. Minor injury leads to disruption of the ligamentous support of the midfoot and, in the absence of protective sensation, a rapidly worsening and unstable dislocation. Evaluation and Diagnosis The typical patient with acute neuroarthropathy presents with painless deformity of the foot, erythema, and swelling. Depending on the length of time since the initial trauma, minor instability, ligamentous disruption, or fracture-dislocation may be present. Unfortunately, the diagnosis of acute neuroarthropathy is frequently delayed and is often missed completely. In the acute phase, as a result of the associated erythema and swelling, patients are frequently treated for presumed infection. Although most patients do not report pain, it is important to remember that acute neuroarthropathy may be painful. 2,9 If pain exists in the presence of acute or chronic neuroarthropathy, the clinician should suspect associated infection. The differential diagnosis includes gout, cellulitis, and osteomyelitis. The absence of systemic signs (e.g., fever, elevated white blood cell count, and elevated sedi- mentation rate) and the presence of a normal blood glucose level effec- tively eliminate infection as part of the differential diagnosis. If the diagnosis of infection is still in doubt, a trial of 2 hours of bed rest and elevation of the limb will be helpful; the swelling associated with acute neuroarthropathy will subside rapidly, 3 whereas that associated with infection will not. Patients with diabetes who present with foot deformity or findings suggestive of neuroarthropathy should be carefully examined for sensory deficit by assessment of light-touch and two-point discrimi- nation. The most accurate and clinically applicable means of evaluat- ing sensation in the office setting is testing with Semmes-Weinstein monofilaments. If a patient is able to perceive sensation when the 5.07 monofilament is used, protective sensation is present. Although most patients with neuroarthropathy have reasonable perfusion of the foot, it may be marginal or inadequate for those who require surgical procedures. A Doppler ultrasound evaluation of the foot should be performed routinely. Healing after surgery is more likely if the Doppler ultrasound indicates pulsatile flow and the ankle-brachial index is greater than 0.45. 16 In our previous report, 4 the average was 0.65, con- firming adequate perfusion in most feet. Radiographs should be obtained with the patient bearing weight; however, this is often not possible due to poor proprioception or contralateral amputation. Radio- graphs will usually display gross disorganization related to the stage of the arthropathy, although early in the course of the disease these findings may be extremely subtle. 2 Two patterns of neuroarthropathy have been described: (1) an atrophic pattern, with massive bone resorption and joint disintegration, and (2) a hypertrophic pattern, with joint destruction, periarticular bone formation, fractures, osteophytes, bone debris, and migration of the bone fragments. The second pattern is seen more often in the ankle than in the foot. 17 Unless the fracture or dislocation is associated with an ulcer or an open wound on the foot, osteomyelitis is rare. Magnetic reso- nance imaging can define the presence (or establish the absence) of soft-tissue infection, but it does not differentiate well between neuroarthropathy and osteomyelitis because both are associated with bone edema. 2 Simultaneous indium- labeled white blood cell scanning and technetium-labeled polyphos- Neuropathic Foot and Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 10 phate scanning (dual-window imaging) may be more helpful in diagnosing infection. 2 Staging and Classification In 1966, Eichenholtz 9 described a combined clinical and radiographic staging system. In stage I, the foot is inflamed, edematous, and erythematous, occasionally with a precipitous onset. Radiographs typically show bone fragmentation. However, this finding may be subtle, particularly in the presence of joint subluxation or dislocation, rather than fracture. In stage II, the reparative process begins. The swelling, erythema, and warmth regress, and radiographs demonstrate coalescence and resorption of bone fragments. In stage III, inflammation is absent (resolved), and consolidation of the bone is radiographically evident. 2,9 Stage III, therefore, implies stability but not necessarily chronicity, because the foot may remain unstable over a long period of time despite coalition of fragments and bone healing. This scenario is particularly applicable to the hindfoot, where bone healing may have occurred but the foot is clinically unstable, with a rocker-bottom deformity; in these circumstances, regardless of chronicity, stage III has not been reached. 3 The anatomic classification pro- posed by Brodsky 2 is clinically useful because it highlights the anticipated duration of treatment required and facilitates more accurate comparative evaluation of deformity. Type I (60% of cases) involves the tarsometatarsal and naviculocuneiform joints. It is rarely associated with chronic instability and is ultimately characterized by symptomatic plantar osseous prominences. Although feet with type I neuroarthropathy are stable, they are usually deformed, which may cause ulceration depending on the magnitude and location of the deformity. 2,3 Type II (20% of cases) involves the subtalar, talonavicular, and/or calcaneocuboid joints; the feet are often grossly deformed and unstable and need longer periods of immobilization. Type IIIA produces the most severe instability, due to dissolution of the talus and ankle, and frequently involves marked varus or valgus with a prominent malleolus, leading to ulceration and infection. Type IIIB is a pathologic fracture of the calcaneus that often leads to progressive secondary pes planus and Achilles tendon insufficiency. General Principles of Management The goal of treatment should be to create or maintain a stable, biomechanically sound, plantigrade foot that can fit in a shoe or brace. When planning treatment, the clinician must consider the particular pattern of injury, the age and activity level of the patient, the degree and expected progression of the consequent deformity, the stage of the disease process, and the presence of complications, such as ulceration or infection. 4,18 The problems caused by neuroarthropathy are usually due to either osseous prominences or persistent instability. 2 Although most patients can and should receive nonoperative care for neuroarthropathy, surgery may be essential for some patients with either acute or chronic disease. In all cases, patient education in prop- er foot care and the avoidance of injury is vital. Whatever treatment approach is selected, the patient must be made aware of the severity of the disease process. Because of neuropathy, however, these patients simply do not recognize the harmful effect of bearing weight on the affected extremity and, despite all advice to the contrary, continue to damage their feet. The need for vigilance regarding the onset of ulceration and infection is therefore essential. Nonoperative Modalities Most cases of neuropathy of the foot or ankle can be satisfactorily managed with nonoperative meth- ods of treatment. Prolonged immobilization is generally the key to an ideal outcome. 2,4,10,11 The principles of this approach are to control swelling, to provide skeletal stability, to protect the soft tissues for an extended period, and to ensure even distribution of forces on the weight-bearing surface of the foot. In the acute stage (Eich- enholtz stage I), closed management involves the reduction of swelling by elevation and rest; in patients with severe swelling, the use of intermittent compression may also be necessary. 19 Once the severe swelling has been reduced, a total-contact cast provides some stability, distributing pressure across the plantar weight-bearing surface of the foot more evenly than a regular cast. When the swelling decreases further and stage II approaches, a removable boot or short leg cast will provide external stability for most patients. 20 In stage III, the goal is to provide even distribution of force over the weight-bearing surface of the foot. This is usually accomplished with a custom-made orthosis, an accommodative shoe, or a protective brace, such as an ankle- foot orthosis (usually necessary for the long-term management of the hindfoot). There is the potential risk of developing neuroarthropathy after an acute sprain or fracture. 3,10,11,18 In general, these injuries are treated in a manner similar to that utilized for patients without neuropathy. If indicated, surgery should not be delayed or avoided simply because the patient is diabetic. If the injury is Mark S. Myerson, MD, and William H. B. Edwards, MB, BS, MS, FRACS Vol 7, No 1, January/February 1999 11 managed with inadequate immobilization, a rapidly developing neuroarthropathy may ensue. If the foot or ankle fracture is nondisplaced or minimally displaced and has a stable configuration, closed management with prolonged casting is an acceptable alternative, but only with close supervision. If the fracture is displaced and either considerable manipulation is needed to reduce it or molding is required to maintain the reduction, an open approach with internal fixation is recommended. Regardless of the method of treatment, prolonged immobilization is often necessary to prevent the development of neuroarthropathy. Pa- tients with diabetes and neuropathy may require double the normal period of immobilization, maintaining non-weight-bearing status for 10 weeks and then weight bearing in a cast for an additional 2 to 4 months or until all warmth and swelling have dissipated. Reconstructive Surgery Reconstructive surgery in the setting of neuroarthropathy is tech- nically challenging. If surgery is contemplated, the risks of failure of fixation, wound problems, sepsis, and amputation should be made clear to the patient. Furthermore, surgery should not be undertaken if the surgeon is unfamiliar with treatment of the insensate foot. Successful management requires a sophisticated team approach, in- volving specialists in infectious disease, vascular surgery, physical therapy, rehabilitation, and pros- thetics. During the acute phase, the foot is hypervascular, soft-tissue cover- age is potentially compromised, and, due to osteopenia, fragmentation of bone makes fixation challenging. Regardless of the location of the arthropathy, open reduction and internal fixation alone is generally unsatisfactory, and primary arthrodesis is usually required to stabilize the foot further. 4 In the acute stage, surgery is needed primarily to prevent soft-tissue damage (i.e., skin necrosis due to pressure of the dislocated bone or other skin problems secondary to cast molding necessary to maintain reduction). Surgery should be contemplated only if the bone will support adequate fixation. For this reason, it is rarely appropriate to operate on the foot, regardless of the pattern of dislocation, if more than 6 weeks has elapsed since the onset of acute neuroarthropathy. It is often difficult to ascertain exactly when the process commenced, because the patient can rarely recognize the initial event or the onset of neuroarthropathy. Surgical cor- rection is more frequently an alternative when there is a dislocation without fracture, but is contraindi- cated if bone fragmentation is already substantial. Reconstruction of the more chronically deformed, unstable foot may be performed in either the subacute or the chronic stage when cast, brace, or shoe modifications can no longer control recurrent ulceration. However, one must determine that the efforts at these treatments have in fact been adequate, because most stable defor- mities, regardless of their magnitude or the appearance of the foot, are well accommodated in an appropriate brace or shoe. If recurrent ulceration occurs, one should first determine whether the protec- tion afforded the foot was adequate before proceeding to surgery. A successful reconstructive procedure depends on a minimum of soft-tissue swelling, reasonable bone quality to support solid fixation of internal devices, adequate vasculari- ty, and the absence of infection. The last-mentioned criterion is some- times difficult to achieve because patients with chronically deformed feet or ankles and severe destructive neuroarthropathy often have associated infection. The surgical planning of the reconstruction must therefore take this into account, because the alternative is amputation. Surgery should not be performed if the foot or extremity is swollen. The reduction of swelling before commencing surgery may be accomplished with 24 hours of bed rest, limb elevation, and mild diure- sis. An intermittent foot compression pump can be used for 12 hours immediately before surgery if swelling remains a problem. How- ever, in the patient with neuropathy, this device should be used cautiously because of the lack of protective sensation. In all patients, the operative tech- nique is of paramount importance. The soft tissues are marginally viable and must be treated cautiously; longitudinal incisions should be made directly to bone without superficial subcutaneous dissection. Incisions on the plantar weight- bearing surface of the foot should be avoided while maintaining broad skin bridges and using minimal skin retraction. 21 Although this approach usually traumatizes superficial sensory nerves, in these cases the foot is already insensate. A tourniquet is not used, and all surgery on the insensate foot is performed with local or regional ankle- block anesthesia. When bleeding impairs visualization, an Esmarch bandage can be applied temporarily. In all cases, arthrodesis is accomplished with rigid fixation and is accompanied by aggressive resection of fibrous tissue, cartilage debris, and synovium; resection of sclerotic bone to achieve congruent bleeding surfaces that provide max- imal contact and stability; judicious use of bone graft; and reduction of soft-tissue tension with wound clo- sure. 22 Autogenous cancellous bone graft is generally used, but if an adequate quantity of autogenous bone is not available, allograft may be considered. Neuropathic Foot and Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 12 Realignment with open reduction is followed by arthrodesis of the involved joints. Wherever possible, rigid screw fixation of the involved bones is used, but due to the difficulty encountered with poor bone quality and osteopenia, it may be necessary to extend the screws across joints into uninvolved bones. When internal fixation is difficult, supplemental external fixation may be appropriate, but the use of any external fixator must be approached cautiously because of the possibility of infection. However, excellent results have been obtained with a ring fixator, and in the presence of gross instability (particularly of the ankle), an external fixator may be used to supplement internal fixation. A ring fixator can be used in the presence of infection. When stable fixation of the hindfoot and ankle is required, a tibiocalcaneal or tibiotalocalcaneal arthrodesis can be performed with the use of an intramedullary nail. Postoperatively, the extremity is immobilized in a bulky bandage with copious cotton padding and posterior or U-shaped plaster splints. Intravenous antibiotic pro- phylaxis is used for 48 hours. Bed rest with strict elevation of the limb is required for the first week. Pa- tients should be carefully evaluated to ensure compliance with respect to restricted weight bearing. If the patient is totally unable to comply, transfer to a chronic-care facility for the appropriate duration is necessary until unrestricted ambulation can begin. Ten days after surgery, the first dressing change is performed, and a short leg cast is applied. Sutures are typically left in place for 3 to 4 weeks, unless wound healing is clearly complete at an earlier time. The length of postoperative casting and protected weight bearing is determined on the basis of the location of the reconstructive procedure and the extent of apparent healing. Typically, a non-weight- bearing cast is used for 2 months, followed by a weight-bearing cast or a cast brace for 4 (midfoot), 6 (hindfoot), or 9 (ankle) months. These times are quite variable, however; the temperature of the foot and the presence of swelling are used as indications of bone and soft-tissue healing. Once temperature and swelling have subsided to more normal levels as compared with the contralateral foot, weight bearing in a cast can commence. A cast brace or shoe is gradually introduced as early as possible without jeopardizing the reconstructive effort. If the patient is reliable and the fracture or arthrodesis is healing, a removable cast brace is applied at 4 to 6 months and remains in place until the extremity is completely stable. Management of Neuroarthropathy in the Midfoot Neither the initial nor the final appearance of the foot should be of major concern to the patient or the treating physician because, despite gross deformity of the midfoot, a shoe can still be fitted. The vast majority of patients with acute midfoot neuroarthropathy may be treated nonoperatively. Nonoperative Approach Although manipulation of the midfoot might temporarily reduce a dislocation, this procedure should not be attempted because of the pressure required to obtain and maintain the reduction. Any undue pressure in the insensate foot will lead to superficial and possibly deep skin loss and infection. Fur- thermore, there are such rapid fluc- tuations in the swelling of the foot that the reduction is rarely maintained. However, when treating an early neuroarthropathy with minimal subluxation and little fragmentation, application of a well-padded and molded cast is preferable in an effort to prevent increasing deformity. Unfortunately, the deformity may worsen in spite of these pre- cautions. Such worsening occurs predominantly because the patient is unable to comply with restricted weight bearing, although it is possible that increasing deformity may occur due to gross ligamentous lax- ity and tendon forces across unstable joints. The cast should be changed at weekly intervals for 2 to 3 weeks and then at 2- to 3-week intervals, depending on the amount of swelling. A total-contact cast is not necessary, as non-weight-bearing status should be maintained. Ambulation in a cast is begun after the extreme swelling and warmth begin to subside (usually at about 6 to 8 weeks), signifying the beginning of bone healing and the commencement of Eichenholtz stage II. At this time, the cast is changed at 3- to 4-week intervals until a stable stage III is reached. Surgical Approach If the fracture or dislocation is grossly unstable, if the presence of severe deformity precludes fitting into a shoe, or if the soft tissue is at risk from an underlying bone prominence, then open reduction with internal fixation and arthrodesis should be considered (Fig. 1). Although this approach to operative treatment of the insensate foot may seem aggressive, there is suffi- cient clinical evidence that a carefully monitored operative approach to the acute unstable midfoot has substantial benefit. 4 Before deciding on a surgical treatment regimen, the clinician should assess the magnitude of the deformity and determine whether the surgical support team can adequately manage the patient. It is preferable to treat a patient nonoper- Mark S. Myerson, MD, and William H. B. Edwards, MB, BS, MS, FRACS Vol 7, No 1, January/February 1999 13 atively than to embark on a complicated and time-intensive treatment program with potentially disastrous consequences attributable to an ill- prepared or inexperienced team. Acute Stage (Eichenholtz Stage I) The procedure begins with two or three longitudinal incisions, depending on the severity of the dislocation. The first incision is medial, between the plane of the anterior and posterior tibial ten- dons, exposing the medial column (which is invariably involved). A second dorsal longitudinal incision is made between the second and third metatarsal bases, extending from the middle of the shafts of the metatarsals proximally to the navicular or talus, depending on the need for exposure of these bones. Occasionally, a third incision is made along the lateral column, dorsal to the fifth metatarsal, exposing the metatarsocuboid joint. Rigid internal fixation should be used. Cannulated self-drilling and self-tapping partially threaded screws of various diameters offer the greatest ease of insertion (Fig. 1, C and D). Smaller screws may not hold dislocations adequately, particularly if it is necessary to gain purchase more proximally in bone of better quality. Insertion of a larger screw from the first metatarsal proximally into the cuboid or calcaneus (i.e., from one stable sec- tion through an unstable segment into another stable portion of the foot) provides the desired greater bone purchase. On occasion, a medially or plan- tarly applied one-third tubular plate or an H plate can be used to increase stability. 18,23 The application of a plate on the plantar surface of the midfoot has been particularly useful for stabilizing the metatarso- cuneiform and cuneiform-navicular joints. 18 Although this system is biomechanically stronger than the use of dorsally applied screws, the exposure is considerably more difficult. Postoperatively, a short leg cast is applied. This cast is changed every 2 to 3 weeks, and weight bearing is not allowed for 8 to 10 weeks. Once swelling and warmth settle (stage II), weight bearing is commenced in a well-fitted and well-padded short leg cast, which is changed every 2 weeks until the foot is stable, as indicated by the absence of swelling and warmth and the appearance of fusion on radiographs. A removable cast- boot may be used instead of a cast, but the patient must be informed about the risks of walking without support. Subacute Stage (Eichenholtz Stage II) During this stage, inflammation decreases, and there is radiographic evidence of progressive bone fragmentation and resorption, making surgical fixation extremely tenuous. A B C D Fig. 1 Preoperative anteroposterior (A) and lateral (B) radiographs of a patient with midfoot neuroarthropathy. Postoperative anteroposterior (C) and lateral (D) radiographs were obtained after reduction and stabilization with cannulated screws. Neuropathic Foot and Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 14 Therefore, surgery is avoided except for the treatment of infection or truly recalcitrant ulceration, which is seen if the foot is grossly unstable. The ideal treatment is nonoperative management with weight-bearing in a total-contact cast or cast-boot, similar to the approach described for stage I. Once the foot has stabi- lized, a gradual transition is made to custom-made orthoses and shoes. A severely unstable foot with a rocker-bottom deformity may not adequately fit in a shoe; a molded ankle-foot orthosis may be required. The unstable midfoot is extremely difficult to manage, and recurrent ulceration is most likely to occur. If surgery is required, the approach is similar to that described for stage I midfoot disease. How- ever, ulceration is often present, and whenever possible, one should avoid surgery if there is an open wound. In these situations, a total- contact cast should be applied. 24 When the ulcer has healed, surgery should be performed immediately. If the ulcer will not heal but surgery is deemed necessary, extreme care should be exercised to prevent postoperative wound complications. During the period of transition from contact casting to orthotic management, close monitoring is required to prevent recurrence of stage II signs or the development of ulceration. 4,18 Occasionally, the foot does not regain stability; in such cases, long-term management in a molded total-contact Òclam shellÓ brace or a Charcot restraint orthotic walker, or ÒCROW,Ó 20 is an excellent option. Chronic Stage (Eichenholtz Stage III) When the condition stabilizes (stage III), patients typically have relatively rigid and often deformed feet. 4 As previously described, 2,4,21 management with custom-molded insoles and shoe modifications is most often effective. However, sur- veillance for additional foot problems (particularly ulceration) is essential; patient education in this regard is vital. It must also be remembered that neuroarthropathy may occur in the same foot at a later date, although it is rarely at the same site; this is particularly so in the case of neuroarthropathy of the midfoot. 4 In cases of recurrent ulceration and underlying bony prominence in a stable midfoot, the deformity should be surgically addressed by simple exostectomy. 2,4,21 However, it is important to be aware that a stable midfoot with an exostosis can be converted to an unstable midfoot by performing an exostectomy. 4 It is unusual for a stable foot to require a realignment osteotomy and arthrodesis to prevent recurrent ulceration, particularly if the prominence is medial and lateral and off the weight-bearing surface. An unstable midfoot requires realignment and stabilization, usually via a closing-wedge osteotomy and arthrodesis with internal screw fixation 4 or use of a medial or plantar plate (Fig. 2). 18,23 Achilles tendon lengthening is always necessary in treating hindfoot equinus. In patients with marked bone loss, threaded Steinmann pins may provide better stability. After a realignment procedure, the foot needs an extended time (5 to 10 months) in cast immobilization until the osseous surfaces are united. 4 Amputation may be a more acceptable option for patients in whom the condition recurs after midfoot realignment; in such cases, a great effort should be made to maintain limb length. 4 Fig. 2 Midfoot neuropathy. A, Preoperative lateral radiograph. B, Lateral radiograph obtained after application of plantar plates. A B Mark S. Myerson, MD, and William H. B. Edwards, MB, BS, MS, FRACS Vol 7, No 1, January/February 1999 15 Management of Arthropathy in the Hindfoot and Ankle General Principles It is important to identify neuropathy in a patient with an acute ankle fracture because such a patient is at risk for rapidly worsening neuroarthropathy. Therefore, the patient must be carefully monitored during treatment. Diabetes is not a contraindication to open reduction and internal fixation, but the presence of neuropathy means that prolonged immobilization is required to prevent the development of neuroarthropathy. 18 This scenario is dif- ferent from that of the patient who presents in an acute, subacute, or chronic stage of established neuroarthropathy and is therefore at marked risk for worsening deformity regardless of the form of immobilization used. In such patients, the weight-bearing axis of the lower extremity no longer falls within the center of the ankle joint due to varus or valgus deformity, but is usually medial or lateral to it. For this reason, despite adequate brace or cast support, the deformity may worsen. In the acute and subacute stages, management primarily involves a well-molded short leg cast until stability is reached. 12 In many cases, however, weight-bearing must be delayed until the acute inflammation and swelling have subsided. For example, it is difficult to determine accurately whether a stable stage has been reached with chronic dissolution and fragmentation of the talus (Fig. 3). In such cases, weight-bearing can commence when the subacute phase is reached, provided the talus is centered under the tibia and remains in the line of the weight-bearing axis of the lower limb. If progressive dissolution of the talus occurs, the consequences are not as serious as they are when medial and lateral talar subluxation occur because the foot remains plantigrade, and varus or valgus instability and deformity are less likely to occur. The indications for operative intervention include marked instability, fixed deformity not manage- able with a total-contact cast, and recurrent ulceration and infection refractory to brace and cast treatment. 12 In these settings, open reduction and arthrodesis of the involved joints is the procedure of choice and may require tibiotalar arthrodesis, tibiocalcaneal arthrodesis after talectomy, or triple or pantalar arthrodesis. 12 Ideally, rigid internal fixation with large cannulated screws is used, but persistent ulceration, infection, or osteopenia may dictate the use of an external fixation device. Accurate alignment (ankle in neutral to 5 degrees of dorsiflexion, 5 to 10 degrees of hindfoot valgus, and external rota- tion matching that on the contralateral side) is essential to prevent maldistribution of force and ulceration in the postoperative period. 12 Postoperatively, non-weight- bearing status should be maintained with use of a cast for 2 to 3 months. Thereafter, protected weight bearing is allowed until arthrodesis is evident both clinically and radiographically or until a stable pseudarthrosis is believed to be present. It is important to real- ize that arthrodesis is not necessary to achieve a successful outcome because stability is the goal of surgery. In our previously reported series, 12 more than 90% of the patients achieved a successful outcome with salvage of a severe deformity. Success should be equated with a stable, noninfected extremity that fits in a brace. Most patients who have under- gone an extended hindfoot or ankle fusion must be protected in a brace, usually an ankle-foot orthosis. Stress fracture of the distal tibia may occur if no brace is used, probably due to the increased concentration of force in the distal portion of the leg (Fig. 4). The use of intramedullary devices has proved invaluable in decreas- ing the incidence of stress fracture and increasing the rate of arthrodesis. Fig. 3 Fragmentation of the talar dome, as visualized on anteroposterior (A) and lateral (B) radiographs. A B Neuropathic Foot and Ankle Fractures Journal of the American Academy of Orthopaedic Surgeons 16 cannulated screws are inserted. Occasionally, as a result of fragmentation, bone loss, or osteopenia, the bone and joints to be fused are not substantial enough to support these large screws. In such situations, the stability of the fusion may be improved by extending the screws across a normal joint into a healthier bone. As an alternative to the use of cannulated screws, a blade plate 25 or an intramedullary device has been successfully used in patients with neuroarthropathy (Fig. 5). A retrograde intramedullary nail has been extremely useful in these patients, but closed insertion of this nail is not recommended because of the difficulty in achieving adequate reduction without open- ing the joint. The insertion tech- nique is important because some- times only one locking screw will fit into the calcaneus if the entry site of the nail is more anterior on the neck of the calcaneus than opti- mal. In the presence of acute or chronic infection, a decision has to be made whether an amputation or a lengthy attempt at salvage and reconstruction would be better for the patient. Many patients are unable to tolerate the prolonged period of convalescence and reha- Surgical Techniques The goal of operative treatment is to provide maximum stability with either internal or external fixation, while facilitating soft-tissue healing and ultimate arthrodesis. The limb is surgically prepared and draped above the knee to improve visualization to attain correct alignment. For almost all ankle, tibiotalocalcaneal, tibiocalcaneal, and pantalar procedures, an extensile lateral approach to the ankle is made after resecting the fibula. Bone graft is harvested from the fibula; a small acetabular reamer is directed with pressure onto the fibula, and the cancellous reamings are preserved for later use. The reamer is also used to decorticate the lateral tibia and calcaneus where appropriate. The medial side of the ankle is usually exposed by resecting the medial malleolus, although it may be best to leave it in place as a medial but- tress to improve the stability of internal fixation. The talus is preserved and incorporated into the fusion mass (i.e., ankle, tibiotalocalcaneal, or pantalar arthrodesis), provided there is perfusion to the body and no extensive osteonecrosis. If osteonecrosis is present, the head and neck of the talus may be preserved because they are invariably perfused and will be incorporated into the fusion mass. The avascular and necrotic seg- ments are debrided until bleeding bone is identified. The hindfoot is then positioned and temporarily secured with guide pins, and radiographs are obtained. If the desired position has been attained, large Fig. 4 Fracture of the distal tibia (arrow- head) after ankle arthrodesis with screw fixation. Fig. 5 Fragmentation or dislocation of the talus and talonavicular joint, depicted on preoperative AP (A) and lateral (B) views, is best treated with talectomy. Postoperative lateral (C) and oblique (D) views illustrate use of a blade plate, supplemented by local allograft bone, for arthrodesis. A B C D Mark S. Myerson, MD, and William H. B. Edwards, MB, BS, MS, FRACS Vol 7, No 1, January/February 1999 17 bilitation essential to recovery from reconstructive surgery; for them, amputation may be the better choice. For those who will under- go a salvage or reconstruction attempt, a staged process is ad- vised, gaining initial stabilization with a ring fixator, usually followed by rigid internal fixation with cannulated screws once the infection is under control. In the absence of infection, an external fixator can be used to supplement tenuous internal fixation. A standard construct includes three tibial 5-mm half-pins (two in line on a single block and one at 45 degrees to them) proximally with an anterior half-ring. A 1.8-mm wire is placed in the calcaneus from posteromedial to antero- lateral, attached to a posterior half- ring, and tensioned. Another 1.8- mm wire is then placed in line with the ring from posterolateral to anteromedial, taking care to avoid the neurovascular bundle, and is tensioned. The construct is supplemented with two threaded 5- mm half-pins introduced into the posterior calcaneus at approxi- mately a 45-degree angle to each other. The construct is completed and compressed with connecting rods. If the fixator is used in conjunc- tion with internal fixation, it is left in place for 2 to 3 months until there is soft-tissue stability, as indicated by decreased swelling and absence of wound breakdown or erythema. If the fixator is to be used as the definitive form of stabilization, it should remain in place until bone stability is present (usually 4 to 6 months). Summary Neuroarthropathy is a disabling disease for the patient and a challenging problem for the orthopaedic surgeon. Not only is the diagnosis of acute disease often delayed, but the management of all stages requires intensive and prolonged care with considerable at- tention to detail and the coordina- tion of a sizable team. The problem is frequently exacerbated by indifference to the disease process on the part of the patient. Untreated, the disease progresses to gross instability, loss of mobility, recurrent ulceration, and sepsis. Treat- ment is aimed at creating or maintaining a stable, biomechanically sound foot that can be accommodated in a shoe and that has no osseous protuberances (which might cause recurrent ulceration). In most cases, this can be achieved with nonoperative measures; major reconstructive surgery is only occasionally needed. Closed management of neuroarthropathy with the use of such modalities as a total-contact cast or a brace is effective for approxi- mately 75% of patients with stage I or stage II disease. Reconstructive surgery is challenging and should not be contemplated unless an experienced team is available to the surgeon. Exostectomy for stage III midfoot ulcers reliably heals the ulcer and permits a return to more normal footwear. 21 Operative cor- rection and salvage result in stability in 93% of the patients who present with severe deformity. 12 Re- construction as an alternative to amputation remains the preferred method of treatment for selected patients. References 1.Charcot JM: On arthropathies of cere- bral or spinal origin. Clin Orthop1993; 296:4-7. 2.Brodsky JW: The diabetic foot, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, 6th ed. St Louis: Mosby-Year Book, 1993, vol 2, pp 877- 958. 3.Marks RM, Myerson MS: Neuroar- thropathy. Foot1995;5:185-193. 4.Myerson MS, Henderson MR, Saxby T, Short KW: Management of midfoot diabetic neuroarthropathy. Foot Ankle Int1994;15:233-241. 5.Cofield RH, Morrison MJ, Beabout JW: Diabetic neuroarthropathy in the foot: Patient characteristics and patterns of radiographic change. Foot Ankle1983; 4:15-22. 6.Sinha S, Munichoodappa CS, Kozak GP: Neuro-arthropathy (Charcot joints) in diabetes mellitus (clinical study of 101 cases). Medicine (Baltimore) 1972;51:191-210. 7.Clohisy DR, Thompson RC Jr: Frac- tures associated with neuropathic arthropathy in adults who have juve- nile-onset diabetes. J Bone Joint Surg Am1988;70:1192-1200. 8.Thompson RC Jr, Havel P, Goetz F: Presumed neurotrophic skeletal disease in diabetic kidney transplant recipients. JAMA1983;249:1317-1319. 9.Eichenholtz SN: Charcot Joints. Spring- field, Ill: Charles C Thomas, 1966. 10.Johnson JTH: Neuropathic fractures and joint injuries: Pathogenesis and rationale of prevention and treatment. J Bone Joint Surg Am1967;49:1-30. 11.Harris JR, Brand PW: Patterns of disintegration of the tarsus in the anaes- thetic foot. J Bone Joint Surg Br1966; 48:4-16. 12.Papa J, Myerson M, Girard P: Salvage, with arthrodesis, in intractable diabetic neuropathic arthropathy of the foot and ankle. J Bone Joint Surg Am1993; 75:1056-1066. 13.Brower AC, Allman RM: Pathogenesis of the neurotrophic joint: Neurotrau- matic vs.neurovascular. Radiology 1981;139:349-354. 14.Knowles HB Jr: Joint contractures, waxy skin, and control of diabetes [editorial]. N Engl J Med1981;305:217- 219. 15.Monnier VM, Vishwanath V, Frank KE, Elmets CA, Dauchot P, Kohn RR: Relation between complications of type I diabetes mellitus and collagen- . with locomotor ataxia and posterior column dys- function of the spinal cord (tabes dorsalis). 1 In 1936, Jordon was the first to associate diabetes with neuroarthropathy. 2 Fractures and dislocations. those who require surgical procedures. A Doppler ultrasound evaluation of the foot should be performed routinely. Healing after surgery is more likely if the Doppler ultrasound indicates pulsatile. occurs predominantly because the patient is unable to comply with restricted weight bearing, although it is possible that increasing deformity may occur due to gross ligamentous lax- ity and tendon

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