Chapter 18. joint-sparing Treatment of Ankle Arthritis With Coronal Plane Deformity. Indications. Beat Hi11ten11a1111, MD.

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1 Chapter 18 joint-sparing Treatment of Ankle Arthritis With Coronal Plane Deformity Beat Hi11ten11a1111, MD Marhus Knupp, MD Alexej Barg, MD Indications Because the etiology of ankle arthritis is posttraumatic in most patients, deformity is a common finding. The deformity can be in the coronal plane (varus or valgus) or in the sagittal plane (procurvatum or recurvatum). ln some patients, the deformity also includes malrotation. Because of its posttraumatic nature, ankle arthritis frequently becomes symptomatic much earlier than does idiopathic arthritis of the hip or the knee. This fact underscores the importance of long-lasting treatment options for this patient group, particularly with regard to joint-preserving options. The natural history of ankle malalignment needs investigation. No prospective study has assessed the influence of malalignment on the ankle joint. However, photometric assessment, gait analysis, and biomechanical studies (in cadaver and animal models) have shown substantial alteration of the biomechanics in ankles with deformities. Furthermore, in most patients, arthritis of the ankle joint is mechanically induced and not of inflammatory nature. On the basis of these findings, correction of supramalleolar alignment in patients with varus or valgus arthritis of the ankle joint (asymmetric arthritis) has gained increasing popularity for the management of early and midstage arthritis to postpone fusion or surgical replacement. The two types of asymmetric arthritis of the ankle joint are primary osseous malalignment with or without secondary ligamentous insufficiency and primary ligamentous malalignment with or without secondary osseous malalignment. ln both types, the deformity may involve not only the ankle joint but also the adjacent structures. Surgical correction may include both osseous and soft-tissue balancing. Numerous authors emphasize the importance of combining osseous and ligamentous balancing to normalize the harmful forces on the joints. In most patients with asymmetric arthritis of the ankle joint, the underlying problem is not a Dr. Hintermann or an immediate family mcmbej has received royalties from, serves as a paid consultant to, and has received research or institutional support from lntegra LifeSciences. Dr. Knupp OJ an immediate family member serves as an unpaid consultant to Integra LifeSciences and ln2bones, and has received resem ch or institutional suppoj t from Mathys AG Bettlach. Neither Dr. Barg JJOJ any immediate family member has received anything of value from or has stocl1 or stoc11 options held in a commercial company OJ institution related directly or indirectly to the subject of this chapter. single-plane deformity but a complex instability pattern that involves the ankle joint, the neighboring joints, and/or the surrounding stabilizing soft tissues. In addition to tilting of the talus in the coronal plane, these factors may result in anterior extrusion of the talus out of the mortise, subtalar ma I positioning due to peritalar instability, and segmental deformities of the foot. In addition to correction of the angle of the distal tibial articular surface (TAS), these patients may require additional procedures in the adjacent joints, ligaments, and tendons. The mechanical axis of the ankle is defined by a line drawn from the center of the femoral head to the middle of the mortise of the ankle. A full-length radiograph of the leg may not be justified as a basic diagnostic tool in daily practice, and the mechanical axis can be difficult to determine with precision intraoperatively, so most surgeons instead use the anatomic tibial axis, which is a line drawn along the long axis of the tibia. An ankle is considered to have a neutral tibial anatomic axis when the line passes slightly lateral to the midsagittal plane of the ankle (tibiotalar joint) (Figure 1, A). lf the line passes to the lateral side the ankle is typically loaded in its medial part (Figure 1, B); however, the ankle can also be loaded in its lateral part in 2015 Amelican Academy of Orthopaedic Surgeons Advanced Reconstruction: Foot and Anh le

2 joint-sparing Treatment of Ankle Arthritis With Coronal Plane Deformity Degenerative Conditions of the Ankle the case of a neutral loading axis or in the case of a loading axis that is moved medially (Figure 1, C). The TAS angle is defined by the anatomic tibial axis and the tibial pla0 fond. If the TAS angle is less than go, the ankle is in varus (Figure 2, A); if 0 the TAS angle is greater than go, the ankle is in valgus (Figure 2, B). However studies have shown that the TAS angle is not the same on full-length images of the lower leg and on mortise views of the ankle. This difference must be taken into account when planning correction of coronal deformity of the distal tibia. The authors of this chapter recommend the use of full-length images of the whole lower leg to assess Figure 1 AP radiographs demonstrate the anatomic tibial axis in a neutral ankle (A), the TAS angle. a varus ankle (8), and a valgus ankle (C). Varus ankle deformity develops from medial compartment overload, which in turn may accelerate articular surface wear. The increased stress on the underlying bone frequently leads to sclerosis of the tibial plafond and a marked decrease in the medial joint space. Usually, in the early stages of the degenerative process, the talus is somewhat symmetric or in slight varus. The talus then tilts progressively into varus position, which results in degenerative changes of the medial compartment. Finally, the pressure on the medial talar body increases, and the medial talar shoulder is changed to a rounded shape. ln many patients, a medial malleolar deformity is found as a response to the overload. ln some instances, an indentation or intra-articular defect develops over the medial aspect of the TAS. As the degenerative arthritis progresses, this varus moment in the ankle causes the medial soft tissues (deltoid ligament and posterior tibial muscle) to contract over time, and a fixed asymmetric deformity of the ankle develops. As the lateral ankle ligaments become incompetent, adaptive changes occur in the peroneal tendons as well, and often an anterofigure 2 Weight-bearing AP radiographs demonstrate the angle of the distal ti?ial lateral extrusion of the talus is seen in joint surface (a), the tibiotalar angle ((3), and the angle of the lateral calcaneal wall (y) in a the setting of severe varus deformity. Osteophytes frequently develop on the anteromedial aspect of the talar neck and tibia. These degenerative changes typically take many months or years to develop. Valgus ankle deformity increases the stress on the underlying bone and thus leads to sclerosis of the tibial plafond on its lateral aspect, the syndesmosis, and the distal tibiofibular joint. Because the mechanical strength of subchondral bone is limited in this area, the tibial plafond typically becomes impacted, resulting in an increased TAS. As the degenerative arthritis progresses, this valgus moment in the ankle causes the medial soft tissues (deltoid ligament and posterior tibial tendon) to become incompetent, and a supple asymmetric deformity of the ankle develops. Osteophytes frequently develop on the anterolateral aspect of the tibia. The more valgus tilt of the talus that occurs, the more the syndesmotic ligaments come under stress. In contrast to varus de- Contraindications whom prostheses cannot be considered a lifelong solution. The absolute contraindications for joint-sparing reconstructive surgical management of the asymmetric arthritic ankle are severe nonmanageable hindfoot instability (floppy hindfoot), severe vascular and neurologic deficiency in the affected extremity, and neuropathic disorders, including Charcot disease. The relative contraindications for this procedure include substantially altered bone quality (such as in patients who have used long-term steroid medication or who have large cysts, osteopenia, or rheumatic disease), advanced age (70 years or older), insulin-dependent diabetes (especially with diabetic neuropathy), tobacco use, and obesity. Local factors that may cause postoperative wound problems include ischemia due to peripheral vascular disease, scars, and infections about the foot. formity, valgus deformity of the ankle usually progresses quickly. A varus or valgus deformity seen in patients with long-standing arthritis often requires additional bony and soft-tissue procedures to correctly balance the ankle in cases in which a supramalleolar osteotomy is done. Debate persists regarding the extent to which patients with established asymmetric ankle osteoarthritis may benefit from corrective osteotomies and soft-tissue balancing. Midterm to long-term results of joint-sparing reconstructive surgical procedures have been good, which indicates that the ankle better tolerates arthritic changes under these conditions than does the hip or the knee. On the basis of these encouraging results, the authors' strategy has changed. As a first step, the authors of this chapter correct the deformity to achieve a well-aligned and balanced ti biota Jar joint. If necessary, total ankle replacement is performed as a second step. Results Given the wide variety of morphologic changes in the asymmetric arthritic ankle, it would be difficult to conduct a randomized prospective study with sufficient power to definitively determine the optimal mode of reconstruction. The following classification system for the varus and valgus ankle was recently proposed: type I consists of tilt of 4 or less (no tilt or congruent joint), and type II consists of tilt of more than 4 (incongruent joint). Type Ill is characterized by varus presentation and joint space narrowing mainly in the medial gutter. A trend toward a better outcome was found in valgus ankles with a preoperative tilt within the mortise. Radiographic improvement was found in patients with Takakura stage 3 arthritis, with the valgus group showing a better out- Alternative Treatments Local management of the surface with arthroscopic debridement, mosaicplasty, distraction arthroplasty, autologous chondrocyte transplantation, and/or osteochondral autograft transfers may relieve symptoms of cartilage damage in the ankle joint. However, because they do not address the underlying problem of altered biomechanics, the benefits may be short-lived. Non-joint-preserving treatments include fusion (arthrodesis) and total ankle replacement. However, fusion of the ankle joint has been shown to result in functional restriction, gait abnormalities, and secondary arthritis in the adjacent joints. Good early and midterm results have been reported for current total ankle replacement designs, but little is known about long-term outcomes. Therefore, this treatment is questionable in younger patients, for come than the varus group. Tendencies toward worse outcomes or failures were found in patients with valgus type I ankles in cases in which the fibular length was not adjusted and in patients with type Ill varus ankles and patients with ankle joint instability. Current studies of the outcomes of surgical reconstruction of asymmetric arthritic ankles consist primarily of retrospective case series (Table 1). Techniques Setup/Exposure The patient is placed in the supine position. The iliac crest is draped if the use of autologous bone graft at the osteotomy site is planned. A pneumatic tourniquet is applied on the thigh. The distal tibia can be approached laterally, medially, or anteriorly. varus ankle (A) and a valgus ankle (8). 144 Advanced Reconstruction: Foot and Anllle Amelican Academy of Orthopaedic Surgeons 2015 Amelican Academy of Orthopaedic Surgeons Advanced Reconstruction: Foot and Anhle 2 145

3 Degenerative Conditions of the Ankle Joint-Sparing Treatment of Ankle Arthritis With Coronal Plane Deformity Table 1 Results of Realignment Surgery in Patients With Ankle Arthritis Table 1 (continued) Results of Realignment Surgery in Patients With Ankle Arthritis No. of Patients Mean Patient Age Authors {Year) {Arthritis Type) Osteotomy Procedure in Years {Range) Takakura et al (1995) 18 (varus) 12 anteromedial opening wedge, 5 dorsolateral 59 (44-72) closing wedge, 1 oblique and shortening fibular Takakura et al (1998) 9 (varus) All medial opening wedge and oblique fibular 35 (12-61) Cheng et al (2001) 18 (varus) All anteromedial opening wedge and oblique 42 (18-78) fibular Stamatis et al (2003) 13 (7 valgus, 6 varus) 7 medial closing wedge, 6 medial opening wedge 46 (16-67) and oblique fibular Tanaka et al (2006) 26 (varus) All medial opening wedge and oblique fibular 54(37-76) Harstall et al (2007) 9 (varus) All lateral closing wedge and shortening fibular 40 (21-59) Pagenstert et al (2007) 35 (22 valgus, 13 varus) 19 medial closing wedge, 3 lateral opening wedge, 43 (26-68) 7 medial opening wedge, 6 lateral closing wedge Hintermann et al (2011) 48 (valgus) 45 medial closing wedge, 3 lateral opening wedge 45 (21-69) and lengthening fibular Knupp M, Stufkens SA, 94 (61 valgus, 33 varus) 60 medial closing wedge, 1 lateral opening wedge, 49 (13-83) Bolliger L, et al (2011) 29 medial opening wedge, 4 lateral closing wedge Lee et al (2011) 16 (varus) All medial opening wedge and oblique fibular 55 (44-75) Mann et al (2012) 19 (varus) Intra-articular medial opening wedge 47 (32-63) DVT = deep vein thrombosis, NA= not available, OA =osteoarthritis, TAR= total ankle replacement. Mean Follow-up in Years {Range) 6.8 ( ) 7.3 ( ) 4( ) 2.8 (1-5) 8.3 ( ) Results Outcomes: 6 excellent, 9 good, 3 fair Complications: 4 delayed unions Outcomes: 4 excellent, 2 good, 3 fair Complications: 1 delayed union Outcomes: 8 excellent, 10 good Complications: 1 late infection, 2 delayed unions Outcomes: 5 excellent, 2 good, 3 fair, 3 poor Complications: 1 delayed union, 1 superficial infection, 1 lateral translation Outcomes: 4 excellent, 16 good, 2 fair, 4 poor Complications: 4 nonunions 4.7 ( ) Outcomes: NA Complications: Zero 5 (3-10.5) Outcomes: NA 7.1 (2 15) 3.6(1 10.5) Outcomes: NA 2.3 (1 6.5) Outcomes: NA 5.9 ( ) Complications: 3 progressive OA, 3 recurrent deformities, 2 nonunions, 2 wound healing problems, 1 DVT, 1 anterior impingement Outcomes of remaining 47 ankles: 44 good or excellent, 1 fair, 2 poor Complications: 1 progressive QA (revised to TAR), 2 delayed unions, 3 delayed wound healing, 2 persistent valgus Complications: 5 wound healing problems, 1 infection, 2 painful neuromas Complications: NA 15 patients were satisfied Complications: 4 progressive OA DVT - deep vein thrombosis, NA= not available, OA = osteoarthritis, TAR = total ankle replacement. No. of Conversions to TAR or Arthrodesis NA NA Zero Zero Level of Evidence 2 (arthrodesis) 1 (arthrodesis) 3 (TAR) 1 (TAR) 9(TAR), 1 (arthrodesis) NA II 1 (TAR), 2 (arthrodesis) The approach is determined based on the selected method of deformity correction and local soft-tissue condition, particularly with respect to scars from previous injuries and surgical procedures. MEDIAL APPROACH A medial approach is used for a closing wedge osteotomy for a valgus ankle (Figure 3) and for an opening wedge osteotomy for a varus ankle. A longitudinal incision is begun over the medial malleolus and extended 10 to 12 cm proximally over the distal tibia. The skin flaps are mobilized with care taken not to damage the saphenous vein and nerve, which run together along the anterior border of the medial malleolus. The posterior tibial tendon lies immediately posterior to the medial malleolus and therefore needs to be exposed with care. The tendon is retracted posteriorly to expose the posterior surface of the distal tibia. The distal tibia is then exposed without stripping the periosteum. LATERAL APPROACH Closing wedge osteotomy for a varus ankle is done using a lateral approach (Figure 4). A 10-cm longitudinal, slightly curved incision is made along the anterior margin of the distal fibula and can be extended distally to end just distal and anterior to the lateral malleolus. The fibula and the tibia are then exposed laterally without stripping the periosteum to avoid devascularization of the bone. At the distal end of the incision, the anterior syndesmosis is exposed. The proximal border of the syndesmosis marks the height of the fibular osteotomy. In cases in which the talus is tilted into varus within the mortise and cannot be repositioned properly by applying eversion stress, the incision is extended to the talofibular joint. Osteophytes on the distal tibia and talus are removed. ANTERIOR APPROACH An anterior approach is used for either complex triplanar correction or staged total ankle replacement. A longitudinal incision is made between the anterior tibial tendon and the extensor hallucis longus tendon starting 10 cm proximal to the joint, approximately midway between the malleoli. The extensor retinaculum is longitudinally dissected along the lateral border of the anterior tibial tendon. The anterior aspect of the tibia is exposed, and the neurovascular bundle is retracted laterally. Usually, the joint is covered by adipose tissue containing a venous plexus. Because the approach for osteotomies is usually extra-articular, the tibiotalar joint itself is not exposed. Care is taken to ensure that the retractors on the medial side are placed beneath the posterior tibial tendon, which lies immediately posterior to the medial malleolus. 146 Advanced Reconstruction: Foot and Anlde American Academy of Orthopaedic Surgeons 2015 American Academy of Orthopaedic Sw;geons Advanced Reconstn1ction: Foot and Anhle

4 ... ~~ Degenerative Conditions of the Ankle joint-sparing Treatment of Ankle Arthritis With Coronal Plane Deformity Instruments/Equipment/ Implants Required A joint distractor and Kirschner wires CK-wires) are useful to gradually open the osteotomy. Appropriate saw blades and chisels are mandatory to do the osteotomy with the goal of destabilizing the opposite tibial cortex as minimally as possible. Fluoroscopy is needed for preoperative evaluation of the ankle, particularly for evaluation of the amount of correction that can be achieved with manual stress. Arthroscopic equipment is required if preoperative evaluation of the ankle joint is p lanned. Appropriate hardware is required for stable internal fixation at the osteotomy site. The authors of this chapter prefer anatomically specific locking plate constructs to achieve maximally stable fixation. Allograft should be readily available if an opening wedge osteotomy is planned for which autologous graft harvesting will not be attempted. c Procedure figure 3 Images of the ankle of a 40-year-old woman "."ho presented with a valgus deformity and congenital flattening of the talus and agenesis of the toes. She was t~eated with closing wedge osteotomy through a medial approach. Standard preoperative AP (A) and lateral (B) weight-bearing radiographs of the ankle joint. C through H, Intraoperative photographs. C, The distal tibia is exposed and Kirschn~r wires are inser.ted. o, The osteotomy is done with slightly more resection on the anterior aspect to ~ch1e.ve more dorsiflexion. E, The bony wedge is removed. F, The appearance of the surgical site after bone removal. G, Closure and compression of the osteotomy using a compression device. H, View of the plate fixed to the proximal tibia. I, lntraoperative AP fluoroscopic image demonstrates overcorrection of the plafond into slight varus. lntraoperativ~ lateral fluoroscopic views demonstrate the foot in maximal dorsiflexion (J) and maximal plantar flex ion (K). 148 Advanced Reconstruction: Foot and Anllle 2 Fluoroscopic assessment is performed under anesthesia before the procedure. With passive manipulation and valgus or varus stress, the extent of correction of the talar position and the amount of lateral and medial instability can be assessed. If the talus cannot be fully corrected within the ankle mortise, the underlying cause should be carefully identified. The technique should be chosen depending on the form and severity of the deformity and on the planned correction. Accordingly, additional surgical techniques have to be considered for appropriate balancing of the ankle. Table 2 presents an outline 2015 Ame1i can Academy of Orthopaedic Surgeons Figure 4 Images of the ankle of a 47-year-old woman who presented with posttraumatic asymmetric valgus osteoarthritis after fibular nonunion. She was treated with closing wedge osteotomy through a lateral approach. A, Preoperative AP radiograph of the ankle. B, lntraoperative photograph shows the lateral exposure and closing wedge osteotomy with removed bone. C, lntraoperative photograph shows internal fixation of the tibia and fibula. In some patients, as in the one shown here, fibular union lags tibial healing. D, AP radiograph of the ankle obtained 3 months postoperatively demonstrates a well-aligned and balanced ankle. of when and how to proceed with additional techniques. To compensate for asymmetric ca rtilage loss at the tibiotalar joint, the surgeon should aim for overcorrection of 2 to 4. The osteotomy is typically placed 3 cm above the tibiotalar joint. If at that height the osteotomy would cause the center of the articular surface to shift away from the anatomic axis of the tibia, the osteotomy should be shifted proximally. VARUSANKLE Lateral Closing Wedge Osteotomy of the Tibia and the Fibula In most instances, the fibula must be shortened according to tibial correction to preserve ankle joint congruency. The shortening can be done with simple bone block removal, an oblique osteotomy, or a Z-shaped osteotomy. The desired osteotomy is done with an oscillating saw Ame1ican Academy of Orthopaedic Surgeons Two K-wires whose paths will intersect at the medial cortex are inserted into the tibia under fluoroscopy. The two osteotomies are done along the K-wires with an oscillating saw, and the wedge is removed (Figure 4, B). After an anatomically shaped plate is mounted with locking screws to the distal tibial fragment, the osteotomy is closed with a compression device. Thereafter, the plate is fixed to the tibia at its proximal part (Figure 4, C). If translation is needed, it is done before fixation is applied. After the desired translational correction is achieved, preliminary fixation is done with one or two K-wires. The plate fixation is then performed. Because the fibula is still fixed to the tibia by both the interosseous membrane and the syndesmotic ligaments, it usually maintains its anatomic position relative to the distal tibia. Nevertheless, its position must be checked fluoroscopically before the fixation plate is applied. Fluoroscopy is used to assess joint congruency and the final position of the tibia and the fibula. Medial Opening Wedge Osteotomy of the Tibia The plane of the osteotomy (Figure 5) is determined under fluoroscopy. In patients with an isolated frontal plane deformity, the osteotomy is done in an anterior to posterior direction, parallel with the talocrural angle. A K-wire is placed from the medial to the lateral cortex. Fluoroscopy is used to check the position of this wire. Subsequently the osteotomy is done with a wide saw blade and is gradually opened with a distractor until the desired correction is achieved. Advanced Reconstruction: Foot and Anlile 2 149

5 Degenerative Conditions of the Ankle Joint-Sparing Treatment of Ankle Arthritis With Coronal Plane Deformity Table 2 Surgical Techniques Used to Balance the Ankle in the Management of Varus and Va Igus Deformity Deformity Type Step Varus 2 Deltoid ligament release Fixed talar tilt or irreducible talus after lateral exostectomy Posterior tibial release External rotation of talus with regard to calcaneus or medial tilt of navicular 3 lateral exostectomy Irreducible talus due to lateral impingement 4 Subtalar fusion Irreducible peritalar dislocation 5 l ateral ligament reconstruction Anterolateral extrusion of talus or preexisting talar tilt of >5 6 Peroneus longus to peroneus brevis transfer long-standing anterolateral extrusion of talus with varussupination deformity or peroneus brevis dysfunction 7 lateralization osteotomy of calcaneus Persistent varus alignment of hindfoot B Dorsiflexion osteotomy of first ray Plantar flexion of first ray 9 Achilles tendon lengthening Achilles tendon contracture or foot dorsiflexion of <10 Subtalar fus ion Important peritalar instability or irreducible peritalar dislocation or stage 3 posterior tibial dysfunction 2 Talonavicular fus ion Fixed supination deformity of forefoot or stage 3 posterior tibial dysfunction 3 Medialization osteotomy of calcaneus Persistent valgus alignment of hindfoot 4 Med ial ligament repair Incompetent superficial deltoid ligament or medial gapping of the tibiotalar joint of > 10 mm 5 Medial ligamentoplasty Incompetent deep deltoid ligament or medial gapping of the tibiotalar joint of > 10 mm 6 Syndesmotic fusion Persistent syndesmotic instability Va Igus Fixation of the correction is achieved with an anatomically shaped I-plate with locking screws. If translation is needed, it is done before fixation is applied. After the desired translational correction is achieved, one or two K-wires are used for provisional fixation. Plate fixation is then performed. Fluoroscopy is used to assess joint congruency and the final position of the tibia and the fibula. Dome Osteotomy of the Tibia First, the fibula is approached, and an osteotomy is done. The center of rotation is determined in accordance with the desired lateral angulation of the distal tibia, and a plate is fastened with a short 150 Indication Technique Advanced Reconstruction: Foot and Anhle 2 screw at that point. A hole in the plate 3 to 4 cm from the screw is used as a drill guide for a 2.5-mm drill bit. The plate is rotated medially and laterally along this radius to create multiple drill holes. By doing so, the surgeon creates an incomplete osteotomy that is finished with the use of a curved osteotome and chisels. Two joint distractors, mounted over K-wires at the anteromedial and anterolateral aspects of the tibia, are used to mobilize the distal tibia and to gradually rotate it until the desired position is obtained. After fluoroscopic confirmation of position, the osteotomy is fixed with one or two plates. Finally, internal fixation of the fibula is done. Correcting Osteotomy of the Fibula The fibula is exposed through a longitudinal incision. An oblique osteotomy 2 to 4 cm in length is done, starting from the distal anterior aspect just above the syndesmotic ligament and extending to the proximally posterior aspect. After an anatomically shaped plate is mounted with locking screws to the distal fibular fragment, the fibula is gradually shortened with a compression device until the desired length is obtained, as evaluated under f1uoroscopy. The plate is fixed to the tibia at its proximal part American Academy of Orthopaedic Surgeons Fig~re 5 Weight-bearing rad.iographs from a 56-year-old man with varus asymmetric arthritis of the ankle and a varus knee. Preoperative AP (A) ~nd Saltzman (BJ views of the.ankle, lateral (C) and AP (DJ views of the foot, and a full-length view of the lower extremity (E). Postoperative AP (Fl and Saltzman (G) views of the ankle, lateral (HJ and AP (I) views of the foot, and a full-length view of the lower extremity (J) of the same patient 2 months after supramalleolar medial opening wedge osteotomy of the distal tibia and lateral closing wedge osteotomy of the proximal tibia. VALGUS ANKLE Medial Closing Wedge Osteotomy The plane of the osteotomy (Figure 6) is de termined under fluoroscopy. Two K-wires are inserted into the tibia under fluoroscopic guidance at the desired height such that they intersect at the lateral cortex (Figure 3, C). Fluoroscopy is used to check the position of the K-wires. After an anatomically shaped I-plate is mounted with locking screws to the distal tibial fragment, the osteotomy is closed with a compression device (Figure 3, G). The plate is fixed to the tibia at its proximal part (Figure 3, H). If translation is needed, it is done before fixation is applied. After the desired translational correction is achieved, one or two K-wires are used for preliminary fixation. The plate fixation is completed. Fluoroscopy is used to assess joint congruency and the final position of the tibia and the fibula. Fibular Osteotomy The fibula is exposed through a longitudinal incision. An oblique osteotomy 2 to 4 cm in length (Figure 7) is done, starting from the distal anterior aspect just above the syndesmotic ligament and extending to the proximal posterior aspect (Figure 7, D). With the aid of a distractor on its anterolateral aspect, the fibula is American Academy of Orthopaedic Surgeons gradually lengthened to the desired length (Figure 7, E). As interfragmentary compression is applied with a compressive clamp, an anatomically shaped plate with locking screws is fixed to the fibula (Figure 7, F). An interfragmentary compression screw may be considered if a plate without locking screws is used. Wound Closure On the medial side, the tendon sheath of the posterior tibial tendon is closed with No. 0 absorbable sutures, and the subcutaneous tissues and the skin are closed with interrupted sutures. On the lateral side, the subcutaneous tissues and the skin are closed with interrupted sutures. Advanced Reconstruction: Foot and Anlzle 2 151

6 Degenerative Conditions of the Ankle joint-sparing Treatment of Ankle Arthritis With Coronal Plane Deformity.. f fa 60- ear-old man with valgus asymmetric arthritis of the ankle. Weight-bearing rad1ographs of the ankle and Coat ~ AP f ~t (D) views. Postoperative AP ankle (E), Saltzman ankle (F), Preoperative AP ankle (A), Saltzman ankle (B), latera.i foot ( ), a~ ft o alleolar medial closing wedge osteotomy of the distal lateral foot (G), and AP foot (H) views of the same patient~ mont s ~ er s~~ram. tibia, medial sliding osteotomy of the calcaneus, and nav1culocunelform Joint fusion. Figure 6 Postoperative Regimen The patient is placed in a short leg splint for 2 weeks, after which the patient uses a pneumatic boot and is instructed to maintain partial weight bearing and to perform range-of-motion exercises. If there are no concerns with the soft tissues and wound healing, continuous passive motion is started and performed three times a day for 1 hour each time. After additional soft-tissue reconstruction, a short leg cast is applied. After bone healing is achieved, usually after 8 weeks, full weight bearing is permitted, and a specific rehabilitation program including strengthening, gait training, and range of motion is started, with 152 gradual return to full activities as tolerated. Thromboembolic prophylaxis is recommended until cast-free full weight bearing is achieved. The use of compressive socks is recommended up to 6 months postoperatively. Avoiding Pitfalls and Complications Because supramalleolar osteotomy is the main step for balancing the ankle, it must be appropriately planned before the surgical procedure begins. For isolated coronal plane deformity, the bone cut, in the sagittal plane, should be perpendicular to the anatomic axis of the tibia to avoid changing the anterior Advanced Reconstruction: Foot and Anlde 2 distal tibial angle (the tilt of the tibial plafond). In patients with anterior extrusion of the talus with subsequent overload in the anterior tibiotalar joint, a slightly larger wedge resection at the posterior aspect of the tibia or a slightly larger opening of the osteotomy anteriorly will move the center of rotation of the talus posteriorly, resulting in a better distribution of the joint load. If the contralateral cortex fractures when an opening wedge osteotomy is done, or if additional translation of the distal tibia occurs, an additional plate at the apex may provide the stability needed to preserve the performed correction. If the hindfoot remains malaligned after supramalleolar correction, an additional calcaneal osteotomy 2015 American Academy of Orthopaedic Surgeons Figure 7 Images of the ankle of a 57-year-old woman who presented with valgus asymmetric arthritis after malunion of an ankle fracture following pronation-external rotation trauma. A, Preoperative weight-bearing AP radiograph of the ankle. B, AP fluoroscopic image obtained after medial closing wedge osteotomy to correct the distal tibial articular surface angle demonstrates that the talus remains tilted and lateralized in the mortise, leaving the medial gutter open (bony contours of the medial malleolus shown by the dotted line). C, AP fluoroscopic image obtained after fibular lengthening osteotomy shows the joint congruency restored after correction of the length and position of the fibula. D through F, lntraoperative photographs show the surgical technique of fibular lengthening osteotomy. D, After exposure of the fibula, a long oblique osteotomy is done starting distally approximately 5 mm above the tibiotalar joint. E, The fibula is distracted until the talus is properly reduced within the ankle mortise as observed under fluoroscopy, and a clamp is used to compress the osteotomy. F, The final position of the fibula is shown after plate fixation. of the hindfoot should be done to address any eccentric pull of the Achilles tendon. Overcorrection or undercorrection can occur if appropriate preoperative planning is not done and, in particular, if fluoroscopy is not used for meticulous control as the K-wires are aimed. Overcorrection of 2 to 4 is recommended by most authors for management of varus or valgus arthritis of the ankle. Inappropriate removal of osteophytes may cause lateral impingement under the fibula, which, in turn, may prevent appropriate repositioning of the talus in the mortise. The posterior tibial nerve is an important consideration, especially in the setting of acute corrections. Varus-to-valgus corrections stretch this nerve, particularly in cases in which the center of rotation of angulation lies distal to the os teotomy line. Acute tarsal tunnel syndrome can originate from 2015 Ame1ican Academy of Orthopaedic Sw;geons acute varus-to-valgus supramalleolar correction. A prophylactic tarsal tunnel release may be indicated in these acute corrections, especially in patients with previous scarring. Delayed union or nonunion may occur if inappropriate fixation fails to withstand applied forces at the osteotomy site. Additionally, graft interposition in opening wedge osteotomies may be a risk factor for delayed union or nonunion; the authors of this chapter Advanced Reconstruction: Foot and Anlde 2 153

7 Degenerative Conditions of the Ankle Joint-Sparing Treatment of Ankle Arthritis With Coronal Plane Deformity have not observed this phenomenon, however. Loss of correction may be the result of inappropriate fixation techniques. In the experience of the authors of this chapter, stable plates with locking screws provide the stability necessary to achieve adequate bone healing. Failure of the reconstruction also may be the result of inappropriate correction of concomitant problems, such as ligamentous incompetence, muscular dysfunction, and inframalleolar deformities. Acknowledgment The authors would like to thank Lilianna Bolliger for her significant support in preparing the manuscript. Pagenstert GI, Hintermann B, Barg A, Leumann A, Valderrabano y. 1.. of varus and valgus ankle osteoarthritis. Clin Ortlwp Relat Res 2007;~~;~~g6~~e;t surgery as alternative treatment Stamatis ED.. ' Cooper PS ' Myers on MS S uprama 11 eo 1 ar osteotomy for the treatment of distal tibial 1 d D and arthnt1s of the ankle joint. Foot Ankle Int 2003;24(10): angu ar e orm1ttes Stufkens SA, Barg A, Bolliger L, Stucinskas] Knup M Hinterman B. angle. Foot Ankle Int 2011;32(3):2 88 _ 293 _ ' p ' n Measurement of the medial distal tibial Stufkens SA van Bergen CJ Blankevo t L D k and val us deform it '.... or ' va~ IJ CN' Hintermann B, Knupp M: The role of the fibula in varus g Y of the t1b1a. A b1omechamcal study.] Bone joint Surg Br 2011;93(9): Bibliography Barg A, Tochigi Y, Amendola A, Phisitkul P, Hintermann B, Saltzman CL: Subtalar instability: Diagnosis and treatment. Foot Ankle Int 2012;33(2): Cheng YM, Huang P], Hong SH, et al: Low tibial osteotomy for moderate ankle arthritis. Arch Orthop Trauma Surg 2001;121(6): Fuchs S, Sandmann C, Skwara A, Chylarecki C: Quality of life 20 years after arthrodesis of the ankle: A study of adjacent joints.] Bone joint Surg Br 2003;85(7): Gougoulias N, Khanna A, Maffulli N: How successful are current ankle replacements? A systematic review of the literature. Clin Orthop Relat Res 2010;468(1): Harstall R, Lehmann 0, Krause F, Weber M: Supramalleolar lateral closing wedge osteotomy for the treatment of varus ankle arthrosis. Foot Ankle Int 2007;28(5): Takakura Y, Takaoka T Tanaka Y Yaii H T s R 1 ost-traum. '. ' ~ ma ' ama1 : esu ts of opening-wedge osteotomy for the treatment of a P at1c varus deformity of the ankle.] Bone joint Surg Am 1998;80(2): Takakura Y Tanaka Y Kumai T T S L b.. ' ' ' ama1 ow ti ial osteotomy for osteoarthritis of the ankl R 1 f operation m 18 patients.] Bone joint Surg Br 1995;77(1): e. esu ts o a new Tana~a Y, Takakura Y, Hayashi K, Taniguchi A, Kumai T, Sugimoto K: Low tibial osteotom for var - arthnt1s of the ankle.] Bone joint Surg Br 2006;88(7): y us type osteo- Valderrabano V, Horisberger M, Russell I, Dou all H Hint... Relat Res 2009;467(7): g ' ermann B. Etiology of ankle osteoarthnt1s. Clin Orthop Valderrabano V, Pagenstert GI, Muller AM, Paul], Hennin er HB Ba.. prostheses: Is there really a difference? Foot Anhle Clin 2012; 7(4):5~5-;~5~ Mobile- and fixed-bearmg total ankle Hintermann B, Barg A, Knupp M: Corrective supramalleolar osteotomy for malunited pronation-external rotation fractures of the ankle.] Bone Joint Surg Br 2011;93(10): Hintermann B, Knupp M, Barg A: Peritalar instability. Foot Ankle Int 2012;33(5): Knupp M, Ledermann H, Magerkurth 0, Hinterman B: The surgical tibiotalar angle: A radiologic study. Foot Ankle Int 2005;26(9): Knupp M, Stufkens SA, Bolliger L, Barg A, Hintermann B: Classification and treatment of supramalleolar deformities. Foot Ankle Int 2011;32(11): Knupp M, Stufkens SA, van Bergen CJ, et al: Effect of supramalleolar varus and valgus deformities on the tibiotalar joint: A cadaveric study. Foot Ankle Int 2011;32(6): Lee WC, Moon JS, Lee K, Byun WJ, Lee SH: Indications for supramalleolar osteotomy in patients with ankle osteoarthritis and varus deformity.] Bone joint Surg Am 2011;93(13): Mann HA, Filippi], Myerson MS: Intra-articular opening medial tibial wedge osteotomy (plafond-plasty) for the treatment of intra-articular varus ankle arthritis and instability. Foot Ankle Int 2012;33(4): Nihal A, Gellman RE, EmbilJM, Trepman E: Ankle arthrodesis. Foot Ankle Surg 2008;14(1): Advanced Reconstruction: Foot and Anlde American Academy of Orthopaedic Sw;geons 2015 American Academy of Orthopaedic Sw;geons Advanced Reconstruction: Foot and Anlde 2 155