The First Experience of Using Customized Fixators in the Surgical Treatment of Abducto-Plano-Valgus Foot Deformity in Children

Original PAPERS 293

УДК 617.586-007.5-089-053.2 https://doi.org/10.17816/PTORS34830

THE FIRST EXPERIENCE OF USING CUSTOMIZED FIXATORS IN THE SURGICAL TREATMENT OF ABDUCTO-PLANO-VALGUS FOOT DEFORMITY IN CHILDREN

©© O.V. Kozhevnikov, I.V. Gribova, S.E. Kralina N.N. Priorov Central Research Institute of Traumatology and Orthopedics, Moscow, Russia  For citation: Kozhevnikov OV, Gribova IV, Kralina SE. The first experience of using customized fixators in the surgical treatment of abducto- plano-valgus foot deformity in children. Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. 2020;8(3):293-304. https://doi.org/ 10.17816/PTORS34830 Received: 09.06.2020 Revised: 16.07.2020 Accepted: 24.08.2020

Background. Abducto-plano-valgus foot deformity is one of the most common diseases affecting children and teens. Recently, various methods of surgical treatment have been proposed for the same. However, despite the availability of various operational methods, there are several contradictions in the feasibility and success of a particular operation. Aim. To improve the technique of Evans Calcaneal osteotomy through the use of customized heel bone fixators. Materials and methods. A total of 30 patients (42 feet) aged 9–15 years with abducto-plano-valgus foot deformity were included. We undertook clinical examination, X-ray, computed tomography, and experimental researches. The surgical treatment consisted of Evans Calcaneal osteotomy, with the use of the standard method of fixation in group 1 (n = 33 feet) and the use of a customized fixator in group 2 (n = 9 feet). Results. The improved technique of Evans Calcaneal osteotomy using a special customized fixator allowed making the necessary correction in 100% of cases. The period of restoration of the heel bone integrity was reduced by an average of 30% (p < 0.05). The period of restoration of the support became faster by almost 45% (p < 0.05). Conclusion. The use of a special customized fixator for Evans Calcaneal osteotomy could significantly improve the outcomes and shorted the treatment time for children with abducto-plano-valgus foot deformity. Keywords: flatfoot deformity; abducto-plano-valgus foot deformity; Evans Calcaneal osteotomy; bone grafts; osteosynthesis; fixation.

ПЕРВЫЙ ОПЫТ ИСПОЛЬЗОВАНИЯ КАСТОМИЗИРОВАННЫХ ФИКСАТОРОВ ПРИ ХИРУРГИЧЕСКОМ ЛЕЧЕНИИ АБДУКТО‑ПЛАНО-ВАЛЬГУСНОЙ ДЕФОРМАЦИИ СТОП У ДЕТЕЙ

©© О.В. Кожевников, И.В. Грибова, С.Э. Кралина Федеральное государственное бюджетное учреждение «Национальный медицинский исследовательский центр травматологии и ортопедии им. Н.Н. Приорова» Министерства здравоохранения Российской Федерации, Москва  Для цитирования: Кожевников О.В., Грибова И.В., Кралина С.Э. Первый опыт использования кастомизированных фиксаторов при хирургическом лечении абдукто‑плано-вальгусной деформации стоп у детей // Ортопедия, травматология и восстановительная хи- рургия детского возраста. – 2020. – Т. 8. – Вып. 3. – С. 293–304. https://doi.org/10.17816/PTORS34830

Поступила: 09.06.2020 Одобрена: 16.07.2020 Принята: 24.08.2020

Обоснование. Абдукто-плано-вальгусная деформация стопы является одним из наиболее частых заболеваний стоп у детей и подростков. В последнее время активно применяют различные методы хирургических вмеша- тельств. Однако, несмотря на разнообразие оперативных подходов, существует большое количество противо- речий в целесообразности и успешности выполнения той или иной операции. Цель — усовершенствовать методику остеотомии пяточной кости по Эвансу путем использования кастомизи- рованных фиксаторов пяточной кости.

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Материалы и методы. Представлено лечение 30 пациентов (42 стопы) в возрасте от 9 до 15 лет с абдукто- плано-вальгусной деформацией стоп. В работе использованы клинический, рентгенологический, компьютерно- томографический, экспериментальный методы исследования. Хирургическое лечение заключалось в прове- дении остеотомии пяточной кости по Эвансу. В одной группе (n = 33) остеосинтез выполняли стандартным способом, в другой (n = 9) — с помощью кастомизированного фиксатора. Результаты. Благодаря усовершенствованной методике остеотомии пяточной кости по Эвансу с применением специального кастомизированного фиксатора удалось осуществить необходимую коррекцию в 100 % случаев. Срок восстановления целостности пяточной кости сократился в среднем на 30 % (p < 0,05). Период восстанов- ления опоры уменьшился практически на 45 % (p < 0,05). Заключение. Использование специального кастомизированного фиксатора при выполнении остеотомии пя- точной кости по Эвансу позволяет улучшить результаты и сократить сроки лечения детей с абдукто-плано- вальгусной деформацией стоп. Ключевые слова: стопа; плоскостопие; абдукто-плано-вальгусная деформация; остеотомия пяточной кости по Эвансу; костные трансплантаты; остеосинтез; фиксация.

Abducto-plano-valgus foot deformity is a very palsy. This modification replaces the originally common orthopedic pathology among pediatric perpendicular plane of the calcaneus osteotomy, patients. Several surgical interventions for this passing 1.5 cm from the line of the calcaneocubital pathology have seen notable improvements in the joint, with an oblique plane (from the proximal- recent decades [1–3]. Although several surgical lateral to the distal-medial direction), and uses approaches exist, indications for those and their a wedging trapezoidal autograft instead of a mixture success rates are inconsistent [4–6]. of several bone autografts, with the autograft in the One of the recognized surgical methods for osteotomy area fixed with several Kirschner wires. the treatment of this foot deformity is the Evans Although several modifications exist to the procedure. This intervention enables eliminating Evans procedure, the procedure outlined below is the displacement of the talus and lengthening the typical to such surgery. lateral edge of the foot to correct the external A layer-by-layer approach to the calcaneus deviation of the forefoot. body along the outer surface of the foot is used. Evans had first performed a modification of The peroneus brevis tendon is lengthened in the calcaneus osteotomy procedure in a patient a Z-shaped manner. A transverse osteotomy of the with poliomyelitis with abducto-plano-valgus foot calcaneus between the medial and anterior articular deformity in 1961 and later published the details facets of the calcaneus, parallel to the calcaneocubital of his technique in 1975 [7]. The focus of this joint and retreating from it posteriorly by 1.5 cm, surgery was to lengthen the lateral column of the is performed using an oscillatory saw. An expander foot. To achieve this, the author had performed is installed in the osteotomy area, using which the an osteotomy of the anterior end of the calcaneus fragments of the calcaneus are moved apart to form in a plane parallel to the calcaneocubital joint and a wedge-shaped diastasis, with the base outward. 1.5 cm behind it. In the osteotomy area, after the The bone defect is filled with a graft, and the bone separation of the calcaneal bone fragments, several fragments are fixed (usually with wires or screws). autografts from the fibular bone were placed The wound is then sutured in layers. as spacers. However, the author noted several Of note, fixation of bone fragments in the overcorrections postoperatively. above-described manner is unreliable. The bone Subsequently, the Evans procedure was modified fragments may be displaced, which may cause by several authors [8–11]. The modifications loss of correction; furthermore, prolonged use of concerned both the direction of the osteotomy a plaster cast (at least 3 months) and avoiding load- plane and the use of auto- or allografts (shape and bearing on the leg are necessitated. Moreover, the quantity) [12–14]. use of autologous bone to fill in the bone defect The Mosk modification [15] of the Evans can cause noticeable additional injury in pediatric procedure is often used in modern surgical patients, which limits the volume of bone that can practice for correcting mobile equino-planovalgus be collected. As such, selecting the precise autograft foot deformity in pediatric patients with cerebral size is challenging; an insufficiently sized autograft

 Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. Volume 8. Issue 3. 2020 Original PAPERS 295 can lead to insufficient correction of the calcaneus lateral process of the calcaneus and the metatarsal valgus, whereas an oversized autograft can lead bone V <5°, and history of surgery. to overtensioning of the plantar aponeurosis and Patient evaluation included clinical examination overcorrection of calcaneal valgus. Furthermore, (assessment of complaints, obtaining medical histo- the donor bone can cause allergic reactions and ry), X-ray examination, computed tomography, and can be rejected, which would increase the risk experimental studies (mechanical and strength). of pyoinflammatory complications. In addition, complications such as graft fracture often Clinical examination develop intraoperatively and postoperatively, and All patients complained of gait abnormality, consolidation is often impaired (alloplasty with rapid fatigability, and pain during prolonged physical wedges requires a long time to reconstruct, and exertion. Examination revealed a decrease in or chips do not have sufficient mechanical strength). absence of the longitudinal arch with a convexity of These challenges prolong the recovery period and the plantar surface in the middle section, retraction complicate the treatment process. along the external-dorsal surface of the foot, heel This study aimed to improve the Evans calcaneal valgus (>10°), transverse hypermobility in the osteotomy procedure with the use of customized middle section of the foot, and abduction of the heel bone fixators. anterior section (the “spying toes” symptom).

X-ray examination Materials and methods X-ray examination was performed for all We included 30 patients (42 feet; aged patients before treatment, immediately after surgery 9–15 years) with abducto-plano-valgus foot (day 1), and at 3, 4, 6, 9, 12, 18, 24, and 36 months deformity who underwent surgical correction after surgery. The feet were radiographed, with between 2017 and 2019 at the Center for Pediatric the patient standing (feet under load), in frontal, Orthopedics of the Priorov National Medical lateral, and Saltzman views. The angle of the Research Center of Traumatology and Orthopedics. longitudinal arch, the calcaneal inclination angle, the The patient population included 6 girls (20%) and talocalcaneal divergence angle in the frontal view, 24 boys (80%). The patients were followed up from the talo-metatarsal angle (Shade line deformity), 6 months to 3 years postoperatively. The average the angle between the calcaneal lateral process and age at the time of surgery was 12.75 ± 0.47 years. the metatarsal bone V, and the angle of the heel Surgical treatment consisted of a lateral lengthening bone valgus were the most significant parameters osteotomy of the heel bone. In 33 cases, surgery in assessing anatomic changes in the foot. was based on the Evans procedure, with wire fixation, and in 9 cases, a customized structure for Computed tomography osteosynthesis of the heel bone was used. Computed tomography was performed for every Inclusion criteria. We included patients aged patient for a detailed assessment of pathologic >8 years, with grade II abducto-plano-valgus changes and deformities in the bones of the foot foot deformity with the following radiometric and the ankle joint, the relationship between parameters: a longitudinal arch angle of 135°–160°, joint structures in several planes, the detection of >5° increase in the talo-metatarsal angle (distortion dislocation of the talus bone, and ruling out tarsal of the Shade line), <15° decrease in the angle coalitions [16, 17]. of inclination of the calcaneus, a talocalcaneal In addition, in 9 pediatric patients, correction divergence angle of 40°–50° on the lateral view and was planned preoperatively, with the size of the >40° on the frontal view, calcaneus valgus of >10° individual fixator determined using multilayer spiral with abduction, abduction of the anterior segment computed tomography. First, we evaluated the bones (the angle between the lateral process of the heel of the foot and the various angles characterizing the bone and metatarsal bone V >5°). deformity. Then, we simulated the restoration of Exclusion criteria. We excluded patients aged the correct proportions in the joints of the foot by ≤8 years, with a vertical talus, talocalcaneal and eliminating the deformity, and the required angle of calcaneonavicular coalitions, the angle between the correction was calculated. The angle of correction

 Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. Volume 8. Issue 3. 2020 296 Original PAPERS was used to determine the diastasis between the were presented as means and standard deviations. heel bone fragments, and the customized fixator was The paired Student t test was used to assess prepared to the exact dimensions. The customized significance. The results were considered statistically heel bone fixator is an H-shaped reconstructive significant at p < 0.05. titanium plate (VT-6 alloy) developed by us, with the design patented in Russia [18]. After simulation Indications for surgical treatment and preparation of patient-specific designs, the Indications for Evans calcaneus osteotomy fixator was 3D-printed. Using a customized fixator were grade II static abducto-plano-valgus foot during surgery ensured necessary correction. deformity in children aged >8 years with the following radiometric parameters: the angle of the Experimental research longitudinal arch of 135°–160°, a >5° increase in the Three series of mechanical and strength tests talo-metatarsal angle (distortion of the Shade line), of the reliability of osteosynthesis of the native a decrease in the calcaneus inclination angle of <15°, calcaneal bone using an H-shaped customized plate a talocalcaneal divergence angle of 40°–50° in the were performed on a universal testing machine lateral view and >40° in the frontal view, calcaneus LFM-50kN (Fig. 1). valgus of >10° in combination with abduction, We studied the reliability of fixation in the abduction of the anterior section (>5° angle plate-bone system during compression and can- between the lateral process of the calcaneus and the tilevered bending, which is of high importance metatarsal bone V). for stable osteosynthesis and retention of cor- In 33 cases, surgery was performed according rection. Under compression, the fixed frag- to the conventional Evans procedure, using wedge- ments remained stable under an average load of shaped cortical-spongious allografts and fixation

0.619 ± 0.384 kN (Fmax = 0.738 kN). An average with wires. In 9 cases, a customized structure was force of 0.188 ± 0.162 kN was needed to induce used for calcaneal bone osteosynthesis, and the transverse shear. The data obtained indicate that defect was filled with bone chips. osteosynthesis of the heel bone with an H-shaped reconstructive plate can withstand a load of approxi Surgical technique mately 60–70 kg, which is a remarkable result in A layer-by-layer approach to the heel bone body pediatric practice. Further addition of external im- along the outer surface of the foot was used, per mobilization would completely avoid postoperative the Evans method. The peroneus brevis tendon was deformities and loss of correction. lengthened in a Z-shaped manner. A transverse Statistical analyses were performed using osteotomy of the calcaneus between the medial Microsoft Excel 2019. The continuous variables and anterior articular facets of the heel bone was

Fig. 1. Mechanical and strength tests of the H-shaped reconstructive plate. a, Native calcaneal bone after wedging osteotomy and fixator installation; b, the testing machine, LFM-50kN; c, registration of the test schedule b c

 Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. Volume 8. Issue 3. 2020 Original PAPERS 297 performed using an oscillatory saw parallel to the calcaneocubital joint and retreating from it posteriorly by 1.5 cm. An expander was installed in the osteotomy area, using which the fragments of the heel bone were moved apart to form a calculated, outward wedge-shaped diastasis, with a base width S and an angle A between the surfaces S of the separated bone fragments (Fig. 2). 2 A customized H-shaped fixation element (reconstructive plate) was inserted into the formed A bone defect. The reconstruction plate is designed in the form of 2 pairs of tabs located centrally and 3 protruding from the lower surface of the plate in 1 the transverse direction from the opposite sides of the plate along the lines of their conjugation with Fig. 2. Formation of wedge-shaped diastasis. 1, Calcaneal the bridge. They are supported by the calcaneus bone; 2, calcaneocubital joint; 3, wedge-shaped diastasis; cortical plate. The pairs of tabs are at an angle and S, the width of the base of diastasis; А, the angle between opposite to each other, with the angle between the the surfaces of the separated bone fragments opposite pairs equal to the angle. A, between the sides of the wedge-shaped diastasis formed. The Subsequently, the calcaneal bone fragments distance between the bone fragments contacting the were fixed relative to each other with 4 screws surfaces and the surfaces of the opposite tabs of the through 2 pairs of holes on opposite sides of the fixing element along the lines of their intersection plate. with the lower surfaces of the opposite sides of The bone defect resulting from the correction the plate is equal to the width S of the base of the was tightly filled with bone chips (Fig. 3). wedge-shaped diastasis formed. The H-shape of the fixator enabled freely

a b c

d e f Fig. 3. Stages of the Evans surgery with the use of a customized H-shaped reconstructive plate. a, Lateral access to the calcaneus body with lengthening of the tendon of the peroneus brevis; b, osteotomy of the calcaneus; c, installation of the H-shaped plate; d, filling the bone defect with chips; e, intraoperative radiogram, lateral view; f, intraoperative radiogram, frontal view

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immersing the grafts in the diastasis zone and

p controlling their adjacency. The wound was then Table Table 1 sutured in layers, and a plaster cast was applied 0.026 0.046 0.026 0.018 0.016

index, index, from the metacarpophalangeal joints to the upper Significance Significance third of the lower leg for 8 weeks.

Results Surgical treatment results 2 ± 1.2 surgery after the after 0.2 ± 0.4 0.3 ± 0.5 6 months months 6 23.7 ± 1.2 122.7 ± 2.2 The treatment results of the 2 groups were compared 6 months after the surgery. The early- Group2 postoperative-period parameters compared inclu ded postoperative wound healing time, the pre Day 1 Day surgery 22 ± 1.2 after the after 0.2 ± 0.4 0.3 ± 0.5 sence of an inflammatory reaction, and other 23.7 ± 1.2 122.7 ± 2.2 complications; the late postoperative period para meters included the time to graft restructuring and

consolidation of the osteotomy zone, on which the resolution of the load on the limb depended, the Before Before

11.3 ± 1 load-bearing capacity of the foot after the start of 6.6 ± 0.9 10.8 ± 1.6 43.4 ± 2.5 151.4 ± 3.3 thesurgery ambulation, the position of the calcaneal bone, and the height of the longitudinal arch, radiographic parameters of foot dynamics. The functional re- p sults of treatment were assessed using the AOFAS 0.028 0.048 0.026 0.016 0.014 Clinical Rating Systems. index, index,

Significance Significance Postoperative wound healing mostly occurred within was 12–14 days). In group 2, no complications were reported. In group 1, 5 patients (15%) had a prolonged wound healing time (up to 3 weeks)

surgery because of aseptic inflammation in reaction to the after the after 0.5 ± 0.5 ± 0.6 6 months months 6 22.1 ± 1.9 24.2 ± 2.3 124.6 ± 2.5 allograft (average wound healing time, 15 days). In addition, in group 1, the time to graft restructuring Group1

and bone defect replacement was significantly longer, by approximately 30%, and load-bearing

Day 1 Day was allowed no earlier than 4.5 ± 0.11 months after surgery after the after 0.3 ± 0.4 0.3 ± 0.4 22.9 ± 1.9 23.5 ± 1.9 122.6 ± 1.9 removal of the fixation wires (patients with wires were not allowed to walk owing to the possible wire

migration and the risk of wire fracture). In group 2, X-ray dosimetry results before and after surgery (mean and mean square deviation) the bone structure restored much faster, and full

Before Before load was resumed after 3.1 ± 0.12 months, even 9.3 ± 3.2 8.1 ± 1.8 43.5 ± 2.1 12.2 ± 1.6 161.2 ± 4.4 thesurgery before the metal fixator was removed, using rational shoes with an instep raiser. The plate was removed after the patient resumed normal ambulation. No patient in this study experienced dislocation and/or destruction of the structure; the screws and

the plate showed no displacement and no loss of

Angle calcaneus correction or subsidence of the graft rearrangement zone was seen. In all patients, the load-bearing capacity of the foot improved through deformity reduction. Longitudinal arch, deg. arch, Longitudinal Calcaneal bone inclination, Calcanealinclination, bone deg. Talocalcaneal divergence divergence Talocalcaneal in frontaldeg. view, Talar-metatarsal Talar-metatarsal line), the Shade of (deformity deg. Between the calcaneus lateral Betweenlateral the calcaneus the metatarsal partand deg. bone V, Clinically, all feet showed functional improvement,

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Table 2 Clinical and functional results of treatment according to the AOFAS scale

Average score Increase Group in average score Before the treatment 6 months after the treatment

1 62.22 ± 12.59 92.14 ± 4.58 29.92

2 62.42 ± 12.19 93.56 ± 5.15 31.14 the heel was located in the midline, the longitu- along the external-dorsal surface of the foot, and dinal arch was well visualized, and the gait im- hallux valgus. Right foot radiography showed the proved. angle of the talocalcaneal divergence of 40° on the Radiographic measurements before and after frontal view, the angle between the lateral segment treatment revealed significant improvement in both of the calcaneus and the metatarsal bone V of 17°, groups with regard to the angle of the calcaneus the angle of the longitudinal arch of 145°, the inclination, the longitudinal arch angle, the talocalcaneal angle of 53° on the lateral view, and talocalcaneal divergence angle in the frontal view, the talar-metatarsal angle of 13°. The mean AOFAS the talar-metatarsal angle (deformity of the Shade score was 64 before treatment (Fig. 4). line), and the angle between the lateral process To eliminate the deformity of the right foot, of the calcaneal bone and metatarsal bone V Evans lateral calcaneal osteotomy was performed (Table 1). using a customized H-shaped reconstructive plate. As shown in Table 1, all parameters showed The defect was filled with bone chips. Additional significant improvement in both groups immobilization with a plaster cast was applied for immediately after surgery. However, after 6 months, 8 weeks. Load-bearing on the foot was allowed some loss of the correction was seen in group 3 months after the surgery. The plate was removed 1 (the angle of the longitudinal arch, the angle after 4 months. One year after the surgery, the between the lateral process of the calcaneus and patient had no complaints. Clinically, the foot was the metatarsal bone V). This could be attributed in the middle position, the heel was along the to both allograft subsidence and the spongious midline, the longitudinal arch was formed well, structure of the heel bone. This was not seen in and support was on the entire plantar surface of group 2. the foot. According to the radiography results, the The mean AOFAS score after treatment was bone-articular relationships in the foot improved; 92.14 ± 4.58 points in group 1 and 93.56 ± 5.15 po namely the angle of the talocalcaneal divergence ints in group 2. These increased significantly com- on the frontal view was 25°, the angle between the pared to the preoperative values in both groups lateral process of the calcaneus and the metatarsal (Table 2). bone V was 0°, the angle of the longitudinal arch was 126°, the talocalcaneal angle on the Clinical case lateral view was 48°, and the talar-metatarsal angle was 0°. The AOFAS score had increased by Patient K., aged 15 years, received the 29 points to 93. diagnosis of abducto-plano-valgus deformity of the right foot and was admitted with the complaints of Discussion gait disturbance, feet deformity (more pronounced on the right), and pain on prolonged walking. This study has some limitations. Specifically, Clinically, she had abducto-plano-valgus deformity the follow-up period after surgical treatment was of the right foot, heel valgus at an angle of 15°, relatively short (complete information can only be tarsal valgus up to 35°, and abduction of the obtained by monitoring the child until the end of anterior section of 20°; the longitudinal arch was growth) and the sample size was small. Further study significantly lowered, with a convexity of the including a larger sample of patients is required for plantar surface in the middle section, retraction definitive conclusions.

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a b c d

e f g h

Fig. 4. Patient K, aged 15 years, with abducto-planovalgus deformity of the right foot. a, b, Appearance of the foot before surgery (calcaneal valgus, flattening of the longitudinal arch); c, d, preoperative radiograms; e, f, radiograms of the right foot after lateral osteotomy of the heel bone with fixation with a customized H-shaped reconstructive plate; g, h, appearance of the foot 1 year after surgery (the calcaneus is along the midline, the longitudinal arch is visualized); i, j, radiograms of the right i j foot 1 year after the surgery

When performing lateral lengthening osteotomy the expense of increased hospital stay. The use of of the heel bone according to the generally autografts (from the wing of the ilium or fibula) to accepted Evans technique, we encountered fill the bone defect causes a significant additional several complications. First, the bone wedges trauma, which limits the collection of graft material corresponding the size of the defect, to avoid in pediatric patients. both hypo- and overcorrection, were prepared In addition, wedge-shaped cortical-spongious intraoperatively, which increased the surgery time. bone grafts require longer time to rebuild than bone Second, the lack of a stable fixation precluded the chips (chips are small, soft, and fill the entire space). possibility of early loading. We could not find In some cases, a fragment of the cortical-spongious fixators for pediatric patients meeting our needs graft can be displaced into the subtalar sinus or the in Russia. Third, selecting the suitable material to plantar side, because during the passage of the wire fill in the bone defect is challenging given that it for fixing the graft and bone fragments, the graft must be mechanically strong, biocompatible, and usually fractures at the sharp part of the wedge. quickly reconstructable. In several cases, wedge- Graft segments may split and fall into the diastasis, shaped cortical-spongious grafts caused allergic which is difficult to notice or control. Subsequently, reactions, causing aseptic inflammation. Therefore, an unfixed fragment of a cortical-spongious graft complete filling of the defect is not possible using with sharp angles is displaced into the sinus or to such materials. Hematoma in the cavities occurs the plantar side. frequently, which increases the risk of infection. To overcome the aforementioned challenges, We could manage these complications, however, at we developed a technique for Evans lateral

 Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. Volume 8. Issue 3. 2020 Original PAPERS 301 calcaneal osteotomy using a customized H-shaped in all planes, which significantly reduces the risk of reconstructive plate. This technique is based correction loss. on multispiral computed tomography data and The design characteristics of the H-shaped leverages modern rapid prototyping technologies. reconstructive plate developed by us significantly This technique yielded high precision, as neither simplify its installation during the surgery, improve overcorrection nor hypocorrection was registered. visual control of the osteotomy area and access to this The size of the H-shaped plate is calculated basis the area, and enable the use small-fraction grafts (bone exact size of the wedge, which in turn is calculated granulate, chips, homogenate of the patient’s own basis the anatomic dimensions of the calcaneus spongious bone) for dense filling of the bone defect, and the required correction angle. The design which may not have significant mechanical strength. characteristics of the plate ensure reliability, low- Furthermore, graft restructuring and replacement of trauma rate with the intervention, the possibility the calcaneus defect were significantly faster with of early axial loading, and the use of small- the customized fixator than with other grafts. fraction grafts for dense filling of the bone defect. The first clinical experience of using the cus- Moreover, the H-shaped plate is manufactured in tomized fixator for calcaneus osteosynthesis du Russia. The positive results from the first use of ring Evans osteotomy yielded no complications, the customized H-shaped reconstructive plate in accurate and stable correction, reduced surgery treatment of abducto-plano-valgus foot deformity time and intraoperative injury, and accelerated in children and adolescents with Evans lateral healing of the calcaneus and the possibility of early calcaneal osteotomy are evidence of the superiority loading. and benefits of this technique. Per this study, this novel fixation method has significant advantages. Additional information Further improvement of the surgical technique is planned. In addition, we are conducting further Source of funding. The work was conducted study into the efficacy of this technique based on within the framework of the State assignment. biomechanical parameters of walking. Conflict of interests. The authors declare no conflict of interest. Conclusion Ethical statement. The study complied with the tenets of the Declaration of Helsinki of the World The Evans procedure is proven to yield good Medical Association, as amended by the Ministry outcomes in the correction of reducible planovalgus of Health of Russia, within article 38, part 5, of deformity of the foot with abduction of the forefoot the Federal Law number 323-FZ on 11/21/2011 and transverse overmobility in the midfoot. Calca- (“On the Fundamentals of Public Health Protection neus osteotomy enables correcting all 3 deformities in the Russian Federation”) and was approved by the at once, namely, eliminating the abduction of the ethical committee of the Priorov National Medical forefoot, raising the arch, and centering the calca- Research Center of Traumatology and Orthopedics neal axis. Because the correction is performed in (protocol number 4, dated 09/08/2019). The authors several planes at once, an accurate mathematical had obtained written voluntary consent from patients calculation is very important for complete correc- (or their legal representatives) toward participation tion of all deformity elements. in the study, manufacture of customized implants, During preoperative planning, using the ca- surgical intervention (including the installation pabilities of multislice computed tomogra- of this product), and publication of anonymized phy, the magnitude of the correction angle, the personal data. size of the wedge-shaped defect, and the vo Author contributions lume of the replacement material required can be O.V. Kozhevnikov created the concept and calculated. design of the study, conducted surgical treatment of The use of a customized fixator for osteosynthesis patients, performed staged and final editing of the of the heel bone during Evans osteotomy ensures manuscript. accurate correction and reliable fixation of the I.V. Gribova created the concept and design calcaneus fragments and prevents their displacement of the study, collected and processed the mate-

 Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. Volume 8. Issue 3. 2020 302 Original PAPERS rial, analyzed the literature, performed test work 8. Tarraf YNE, Basha NELD, Sheta RA. Lateral calcaneal and surgical treatment of patients, and wrote the lengthening osteotomy in management symptomatic flexible flat foot. Annals of International medical and article. Dental Research. 2017;3(6). https://doi.org/10.21276/ S.E. Kralina collected and processed the mate- aimdr.2017.3.6.OR6. rial, performed surgical treatment of patients, ques- 9. Trnka HJ, Easley ME, Myerson MS. The role of cal- tionnaire survey, and editing the manuscript. caneal osteotomies for correction of adult flatfoot. All authors made significant contributions Clin Orthop Relat Res. 1999(365):50-64. https://doi. org/10.1097/00003086-199908000-00007. to the research and preparation of the article, read and approved the final version before its publica- 10. Roche AJ, Calder JD. Lateral column lengthening osteotomies. Foot Ankle Clin. 2012;17(2):259-270. tion. https://doi.org/10.1016/j.fcl.2012.03.005. 11. Andreacchio A, Orellana CA, Miller F, Bowen TR. References Lateral column lengthening as treatment for planovalgus foot deformity in ambulatory children with spastic 1. Фёдоров М.А. Современное состояние вопроса cerebral palsy. J Pediatr Orthop. 2000;20(4):501-505. хирургического лечения плосковальгусной дефор- https://doi.org/10.1097/01241398-200007000-00015. мации стоп у детей // Вопросы реконструктив- ной и пластической хирургии. – 2016. – Т. 19. – 12. Zwipp H, Rammelt S. Modified Evans osteotomy for № 3. – С. 26–35. [Fedorov MA. The current state the operative treatment of acquired pes planovalgus. of surgical treatment of planovalgus feet deformity Oper Orthop Traumatol. 2006;18(2):182-197. https:// in children. Voprosy rekonstruktivnoy i plasticheskoy doi.org/10.1007/s00064-006-1170-6. khirurgii. 2016;19(3):26-35. (In Russ.)]. https://doi.org/ 13. Патент РФ на изобретение № 2676665/ 20.02.2017. 10.17223/1814147/58/03. Бюл. № 1. Кенис В.М., Сапоговский А.В. Способ 2. Булатов А.А., Емельянов В.Г., Михайлов К.С. Пло- определения уровня остеотомии пяточной кости сковальгусная деформация стоп у взрослых (обзор при операции Эванса. [Patent RUS No. 2676665/ иностранной литературы) // Травматология и орто- 20.02.2017. Byul No. 1. Kenis VM, Sapogovskiy AV. педия России. – 2017. – Т. 23. – № 2. – С. 102–114. Sposob opredeleniya urovnya osteotomii pyatochnoy [Bulatov AA, Emel’yanov VG, Mikhaylov KS. Adult kosti pri operatsii Evansa. (In Russ.)] acguired flatfoot deformity (review). Traumatology and Orthopedics of Russia. 2017;23(2):102-114. (In Russ.)]. 14. Патент РФ на изобретение № 2602935/ 25.09.2015. https://doi.org/10.21823/2311-2905-2017-23-2-102-114. Бюл. № 32. Тимаев М.Х., Сертакова А.В., Кур- кин С.А., и др. Способ лечения плоско-вальгусной 3. Tennant JN, Carmont M, Phisitkul P. Calcaneus osteo деформации стопы у детей. 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Information about the authors

Oleg V. Kozhevnikov — MD, PhD, D.Sc., Head of the Олег Всеволодович Кожевников — д-р мед. наук, за- 10th Traumatological and Orthopedic Children’s Depart- ведующий 10-м травматолого-ортопедическим детским ment. National Medical Research Center of Traumatology отделением. ФГБУ «НМИЦ ТО им. Н.Н. Приорова» and Orthopedics n.a. N.N. Priorov, Moscow, Russia. https:// Минздрава России, Москва. https://orcid.org/0000-0003- orcid.org/0000-0003-3929-6294. E-mail: kozhevnikovov@ 3929-6294. E-mail: [email protected] cito-priorov.ru

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Inna V. Gribova* — MD, PhD, Senior Researcher of Инна Владимировна Грибова* — канд. мед. наук, the 10th Traumatological and Orthopedic Children’s старший научный сотрудник 10-го травматолого-орто Department. National Medical Research Center of педического детского отделения. ФГБУ «НМИЦ ТО Traumatology and Orthopedics n.a. N.N. Priorov, Moscow, им. Н.Н. Приорова» Минздрава России, Москва. https:// Russia. https://orcid.org/0000-0001-7323-0681. E-mail: orcid.org/0000-0001-7323-0681. E-mail: [email protected]. [email protected]. Svetlana E. Kralina — MD, PhD, Senior Researcher Светлана Эдуардовна Кралина — канд. мед. наук, of the 10th Traumatological and Orthopedic Children’s старший научный сотрудник 10-го травматолого- Department. National Medical Research Center of ортопедического детского отделения. ФГБУ «НМИЦ Traumatology and Orthopedics n.a. N.N. Priorov, Moscow, ТО им. Н.Н. Приорова» Минздрава России, Москва. Russia. https://orcid.org/0000-0001-6956-6801. E-mail: https://orcid.org/0000-0001-6956-6801. E-mail: Kralina_s@ [email protected]. mail.ru.

 Pediatric Traumatology, Orthopaedics and Reconstructive Surgery. Volume 8. Issue 3. 2020