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Background Varus knee correction may affect the ankle and subtalar joints and impact the prognosis of ankle arthritis because the weight-bearing load on the lower extremity extends from the hip to the foot. We aimed to evaluate the changes in the mechanical axis and the weight-bearing axis of the ankle after varus knee surgery. Methods Patients with a varus knee were followed up after undergoing high tibial osteotomy or total knee replacement arthroplasty. The inclusion criteria were age (>18 years) and a history of preoperative and postoperative scanograms. The postoperative change to the ankle joint axis point on the mechanical axis and weight-bearing axis according to the hip–knee–ankle angle correction was adjusted by multiple factors using a linear mixed model. Results Overall, 257 limbs from 198 patients were evaluated. The linear mixed model showed that the change in the ankle joint axis point on the mechanical axis was not statistically significant after high tibial osteotomy and total knee replacement arthroplasty (p = 0.223). The ankle joint axis point on the weight-bearing axis moved laterally by 0.9% per degree of postoperative hip–knee–ankle angle decrease (p Conclusions Varus knee correction could affect the subtalar joint and the ankle joint. Our findings require consideration when utilized during pre- and postoperative evaluations using the weight-bearing axis of patients undergoing varus knee correction.

This study evaluated the rates and annual trends of pediatric CT scans in South Korea using a nationwide population-based database.Data regarding pediatric CT scan usage between 2012 and 2017 were retrieved from the health insurance review and assessment service. Data on the age, sex, diagnosis, and the anatomical area of involved patients were also extracted.A total of 576376 CT examinations were performed among 58527528 children aged below 18 years (9.8 scans/1000 children), and the number of CT examinations per 1000 children was noted to have increased by 23.2% from 9.0 in 2012 to 11.0 in 2017. Specifically, the number of CT examinations increased by 32.9% for the 6-12 years of age group (7.4/1000 to 9.8/1000) and by 34.0% for the 13-18 years of age group (11.4/1000 to 15.3/1000). Moreover, majority of the CT scans were limited to the head (39.1%), followed by the extremities (32.5%) and the abdomen (13.7%). Notably, the number of extremity CT scans increased by 83.6% (2.3/1000 to 4.2/1000), and its proportion as compared to other scans increased from 25.3% to 37.7%.CT scans in the pediatric population increased continuously from 2012 to 2017 at an annual rate of 4.4%. Therefore, physicians should balance the benefits of CT with its potential harms from associated radiation exposure in pediatric patients.본 연구는 전국 인구 기반 데이터베이스를 이용하여 국내 소아 전산화단층촬영의 비율과 연간 추세를 평가하였다.2012년부터 2017년까지 국내에서 촬영된 소아 전산화단층촬영에 대한 건강보험 심사평가원의 데이터를 사용하였다. 연령, 성별, 진단명 및 해부학적 위치에 대한 데이터를 같이 추출하여 분석하였다.18세 미만 어린이 58527528명을 대상으로 총 576376건의 전산화단층촬영이 시행되었다(1000명당 9.8회). 어린이 1000명당 전산화단층촬영 횟수는 9.0회에서 11.0회로 23.2% 증가했다. 전산화단층촬영 건수는 6–12세 그룹에서 32.9%(1000명당 7.4회에서 9.8회로 증가), 13–18세 그룹에서 34.0% 증가했다(1000명당 11.4회에서 15.3회로 증가). 부위별 전산화단층촬영의 비율은 두부(39.1%), 사지(32.5%), 복부(13.7%) 순서로 확인되었다. 사지 전산화단층촬영 횟수는 83.6% 증가했으며(1000명당 2.3회에서 4.2회로 증가) 사지 전산화단층촬영의 비율은 25.3%에서 37.7%로 증가했다.소아 환자의 전산화단층촬영은 2012년부터 2017년까지 매년 4.4%의 속도로 지속적으로 증가했다. 따라서 의사는 소아 환자에서 전산화단층촬영으로 인한 이득과 방사선 노출로 인한 잠재적인 피해를 적절히 고려하여 신중하게 촬영을 결정해야 한다.

OBJECTIVE We aimed to investigate the progression of patella alta (PA) in patients with cerebral palsy (CP) using the Koshino-Sugimoto (KS) index and assess associated risk factors. METHOD Participants in our retrospective study met the following inclusion criteria: patients with CP who visited our institute from May 2003 to December 2019, were ≤18 years of age, were followed up for >2 years and had at least two lateral knee radiographs. KS indices of both knee radiographs were measured for each patient. A linear mixed model was implemented. RESULTS Our participants included 222 CP patients. KS index values were measured via 652 knee radiographs. Reference values of the KS index for those between 4 and 18 years of age were determined according to Gross Motor Function Classification System (GMFCS) levels. In all GMFCS levels, the KS index decreased with patients' ages (P < 0.0001). In groups where the KS index increased, GMFCS levels IV (P = 0.0045) and V (P = 0.0040) were statistically significant. CONCLUSIONS Change in the KS index values indicates that PA improves as patients age within all GMFCS levels. However, in patients with GMFCS levels of IV and V, progressive PA is expected.

Aims Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP. Methods We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement. Results A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046). Conclusion We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198–203.

BACKGROUND Idiopathic pes planovalgus is one of the most common foot deformities in children and adolescents. However, there is a discrepancy between subjective symptoms and radiographic severity in idiopathic planovalgus deformity, and very few studies have investigated this aspect. Further, the assessment of subjective symptoms in patients with pes planovalgus requires a quantitative scoring system for making meaningful comparisons, such as the Oxford Ankle Foot Questionnaire for Children (OxAFQ-c) and that for parents (OxAFQ-p). Therefore, the purpose of this study was to evaluate the factors affecting the symptoms of idiopathic planovalgus using the OxAFQ. METHODS All patients who were ≤18 years of age, had visited our clinic for the evaluation of pes planovalgus deformity, and had completed the OxAFQ were included in this study. The anteroposterior talo-first metatarsal, lateral talo-first metatarsal, and hallux valgus angles were measured on weight-bearing radiographs. The data were analyzed using a multiple regression model, with age, sex, and radiographic indices as explanatory variables. RESULTS Overall, 123 patients were enrolled in this study, and 246 standing foot radiographs were evaluated along with scores in each domain of the OxAFQ. The factors affecting physical domain scores in the OxAFQ-c were female sex (p = 0.047) and the anteroposterior talo-first metatarsal angle (p = 0.033). Age of ≥10 years was a significant factor (p < 0.05) affecting all domains in both the OxAFQ-c and OxAFQ-p other than the physical domain score. CONCLUSIONS Although pes planovalgus deformity is 3-dimensional, the forefoot abduction component of the deformity should be carefully assessed as it is closely related to subjective symptoms. Further, in female patients with a more severe anteroposterior talo-first metatarsal angle, an aggravation of symptoms with aging should be expected when managing pes planovalgus deformity. LEVEL OF EVIDENCE Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background Some patients with cerebral palsy (CP) exhibit excessive knee flexion at initial contact followed by knee hyperextension (KE) in mid-stance. Research question This study investigated the change in sagittal kinematics after distal hamstring lengthening (DHL) and triceps surae lengthening procedures in CP patients with KE, and compared it to those without KE. In addition, the risk factors for the worsening of postoperative KE were analyzed. Methods Consecutive 312 patients (596 limbs) with CP who underwent DHL and triceps surae lengthening were included. All patients underwent preoperative and 1-year postoperative three-dimensional gait analysis. Patients’ limbs were divided into the KE and knee flexion (KF) groups, according to preoperative minimum knee flexion in stance. KE was defined as minimum knee flexion in stance less than 0°. Results The KE and KF groups included 130 and 466 limbs, respectively. Knee and ankle sagittal kinematics significantly improved after surgery in both groups. Minimum knee flexion in stance significantly increased from -6.6˚ to 0.5˚ in the KE group, but decreased from 14.6˚ to 7.8˚ in the KF group. Among the KE group, minimum knee flexion in stance improved in 103 limbs (79.2 %), but worsened in 27 limbs (20.8 %). Degree of preoperative KE was the only factor significantly associated with postoperative worsening of KE (p=0.002). The cutoff value for the worsening of KE was -5.8˚ of preoperative minimum knee flexion in stance. Significance This study demonstrated that the sagittal kinematics of the knee and ankle joints improved after DHL and triceps surae lengthening procedures in CP patients with and without KE. Preoperative degree of KE was a risk factor for the worsening of KE after surgery. Therefore, careful selection for indication of DHL is required to prevent postoperative KE due to overlengthening of the hamstrings, particularly in patients with severe preoperative KE.

Background This study evaluate the radiographic changes in the mid-tarsal joint, including the calcaneocuboid and talonavicular (TN) joints after calcaneal lengthening for planovalgus deformity in children. Methods This study included 38 patients (68 feet) who underwent calcaneal lengthening for planovalgus deformity. Radiographic osteoarthritic changes at the CC or TN joint were defined as modified Kellgren–Lawrence grade of ≥1. Results Among the 68 feet, 31 feet (45.6%) showed radiographic osteoarthritic changes at the CC joint and 20 (29.4%) showed changes at the TN joint. Risk of radiographic osteoarthritic changes at the CC joint was associated with increased age at surgery (OR = 1.2, p = 0.038). Risk of radiographic osteoarthritic changes at the TN joint was associated with increased age at surgery (OR = 2.2; p = 0.002), preoperative AP talus-1st metatarsal angle (OR = 1.1; p = 0.044), and degree of CC subluxation (OR = 2.1; p = 0.007). Conclusions Surgeons should consider the risk factors in the surgical correction of planovalgus deformity to prevent mid-tarsal arthritis.

Introduction: Identifying risk factors associated with developmental dysplasia of the hip (DDH) is essential for early diagnosis and treatment. Breech presentation is a major DDH risk factor, possibly because of crowding of the fetus within the uterus. In multifetal pregnancy, fetuses are generally smaller than singletons, which may obscure the effect of breech presentation on fetal hips. Only a few studies have investigated the occurrence of DDH in multifetal pregnancies. In this study, we aimed to evaluate whether the breech presentation is a major risk factor of DDH in twin pregnancies. Methods: This retrospective study included 491 consecutive live births (after 23+0 weeks gestation) delivered through cesarean section with at least 1 baby with noncephalic presentation in single or twin pregnancies from April 2013 to October 2018. We analyzed the incidence of DDH and its associated factors, including sex, breech, and multifetal pregnancy, with a generalized linear mixed model. Results: The incidence of DDH was 12.5% in singleton with breech presentation, 9.8% in twin-breech presentation, and 0.7% in twin-cephalic presentation. Multivariate analysis showed that singleton-breech presentation (P=0.003), twin-breech presentation (P=0.003), and female sex (P=0.008) were independent risk factors for DDH. Conclusion: Breech presentation is an independent risk factor for DDH in twin pregnancies, although twin pregnancy itself is not an independent risk factor for DDH.

BACKGROUND This study investigated the effect of screw configuration on the rate of correction of coronal angular deformity of the knee joint in children who underwent guided growth using the tension-band plate. METHODS Consecutive patients (76 patients with 154 physes; mean age: 11.8±2.2 y) who underwent guided growth using the tension-band plate for coronal angular deformity (genu varum or genu valgum) were included. The mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, and screw angle were measured from the teleroentgenograms of preoperative and postoperative periodic follow-up visits. RESULTS The mean initial screw angle and the mean rate of correction were 16.7±10.5 degrees and 6.5±5.3 degrees per year, respectively. The rate of correction was significantly affected by age at surgery, sex, physis treated, severity of deformity, and rate of change in screw angle (all P

This study aimed to estimate the annual change in radiographic indices for juvenile hallux valgus (JHV) and to analyze the factors that influence deformity progression.Patients aged15 years who had JHV and were followed up for at least 1 year were included. Hallux valgus angle (HVA), hallux interphalangeal angle, intermetatarsal angle, metatarsus adductus angle, distal metatarsal articular angle, anteroposterior talo-first metatarsal angle, and lateral talo-first metatarsal angle were evaluated. The progression rate of HVA was adjusted by multiple factors by using a linear mixed model.A total of 133 feet were included. The HVA and distal metatarsal articular angle both increased by 0.8° per year (p0.001 and p=0.003, respectively). HVA increased by 1.5° per year (p0.001) at under the age of 10, and the HVA progression in the older patients was not statistically significant.JHV deformity could progress with aging. Most deformity progression could occur before the age of 10 years.

The present study investigated the factors influencing the early clinical outcomes after ankle fracture surgery. We included 88 patients, who had undergone implant removal surgery at 1 year after ankle fracture surgery, with ankle computed tomographic (CT) scans obtained before ankle fracture surgery and at implant removal available. We collected demographic information, including age, sex, the presence of diabetes mellitus, level of trauma energy, and fracture classification from the medical records. We also recorded the fracture height using the radiographs and CT images. The medial joint space and articular incongruity were assessed on the follow-up radiographs and CT scans. Bone attenuation was measured by placing a circular region of interest around the ankle joint on the preoperative CT image. The postimplant removal outcomes were assessed using 2 functional questionnaires, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale and Foot and Ankle Outcome Score (FAOS). Significant factors related to the AOFAS ankle-hindfoot scale scores and FAOS were identified through univariate analysis using age, sex, radiographic measurements, and CT findings as explanatory variables, followed by multiple regression analysis. On multiple regression analysis, the total FAOS was independently related to the AO classification (p = .003) and Lauge-Hansen classification (p = .003). The total AOFAS ankle-hindfoot scale score was related to articular incongruity (p = .044). The early clinical outcomes after ankle fracture surgery were affected by involvement of the ankle joint fracture rather than the lateral malleolus fracture height. Female sex and the presence of postoperative articular incongruity correlated with inferior early clinical outcomes.

Background The purpose of this study was to identify differences in caregiver responses to Korean-language and English-language versions of the Caregiver Priorities & Child Health Index of Life with Disabilities (CPCHILD) questionnaire. Methods Patient data were acquired from the Cerebral Palsy Hip Outcomes Project database, which was established to run a large international multicenter prospective cohort study of the outcomes of hip interventions in cerebral palsy. Thirty-three children whose caregivers had completed the Korean version of CPCHILD were matched by propensity scoring with 33 children whose parents completed the English version. Matching was performed on the basis of 12 covariates: age, gender, gross motor function classification system level, migration percentage of right and hip, seizure status, feeding method, tracheostomy status, pelvic obliquity, spinal deformity, parental report of hip pain and contracture interfering with care. Results There were no significant differences in CPCHILD scores for section 4 (Communication and Social Interaction), and section 5 (Health) between two groups. Korean-language CPCHILD scores were significantly lower than English-language CPCHILD scores for section 1 (Personal Care/Activities of Daily Living), section 2 (Positioning, Transferring and Mobility), section 3 (Comfort and Emotions) and section 6 (Overall Quality of Life) as well as in terms of total score. Conclusions Cultural influences, and the community or social environment may impact the caregivers’ perception of the health-related quality of life of their children. Therefore, physicians should consider these differences when interpreting the study outcomes across different countries.

Background In order to optimize the tenogenic differentiation of mesenchymal stem cells (MSCs), researchers should consider various factors. However, this requires testing numerous experimental settings, which is costly and time-consuming. We aimed to assess the differential effects of transforming growth factor beta-3 (TGF-β3) on the tenogenesis of tonsil-derived MSCs (T-MSCs) and bone marrow-derived MSCs (BM-MSCs) using response surface methodology (RSM). Methods Bone marrow and tonsillar tissue were collected from four patients; mononuclear cells were separated and treated with 5 or 10 ng/mL of TGF-β3. A full factorial experimental design with a categorical factor of 0 was employed to study the effect of tension based on T-MSCs. Eighty-four trials were fitted with RSM and then used to obtain mathematical prediction models. Results Exposure of T-MSCs and BM-MSCs to TGF-β3 increased the expression of scleraxis (SCX), tenomodulin (TNMD), decorin, collagen I, and tenascin C. Expression of most of these factors reached a maximum after 2–3 days of treatment. The model predicted that the values of the tenocyte lineage-related factors assessed would be significantly increased at 2.5 days of culture with 2.7 ng/mL of TGF-β3 for T-MSCs and at 2.3 days of culture regardless of TGF-β3 concentration for BM-MSCs. Conclusions This study demonstrated that the RSM prediction of the culture time necessary for the tenogenic differentiation of T-MSCs and BM-MSCs under TGF-β3 stimulation was similar to the experimentally determined time of peak expression of tenocyte-related mRNAs, suggesting the potential of using the RSM approach for optimization of the culture protocol for tenogenesis of MSCs.

Background Pathologic gait is common in patients with cerebral palsy (CP). Single-event multilevel surgery (SEMLS) is a combination of surgical procedures to improve pathologic gait in patients with CP. However, the effect of each procedure is difficult to predict. The gait deviation index (GDI) is useful in comparing pre- and postoperative improvement. Research question In this study, we evaluated the degree of GDI improvement in patients with CP and analyzed factors related to surgical outcomes. Methods We screened patients seen between May 2003 and December 2019 via a clinical data warehouse to identify those with CP who had been followed up for >1 year and who had undergone SEMLS. The inclusion criteria were (1) CP patients with GMFCS levels I, II and III, (2) patients who underwent SEMLS, (3) and patients who underwent 3D gait analyses preoperatively and at least 1 year postoperatively. A linear mixed model was used to model GDI improvement, assess effects of covariates, and examine factors that contributed to improvement. Results Overall, 544 patients were included. The average improvement in overall GDI was 8.9 ± 12.3, 9.6 ± 12.0, and 6.4 ± 8.6 in Gross Motor Function Classification System (GMFCS) levels I, II, and III, respectively. In GMFCS level II patients, GDI improvement decreased by 0.26 points with a 1-year delay in surgery (p = 0.0022). Within each group of GMFCS levels, femoral derotation osteotomy (FDO) was a significant factor in GDI improvement in GMFCS levels I and II. Rectus femoris transfer (RFT) and supracondylar extension osteotomy (SCO) were significant factors in GMFCS level II. No single procedure was shown to affect improvement in GMFCS level III. Significance Postoperative GDI improved in all levels of GMFCS. Particular procedures especially affected postoperative improvement in GDI in levels I and II. Our data do not mean to set an indication for particular procedures; however, in GMFCS levels I, II patients, particular procedures, such as FDO, yielded a greater GDI improvement in our data set.

The purpose of this study was to determine the reliability of numerous radiographic measurements of the skeletally immature ankle joint, timing of ossification of medial malleolus and appearance of tibial incisura and differences in the values of radiographic measurements based on age and sex.This study included 590 subjects (0-15 years), who underwent ankle AP, lateral and mortise radiographs. Presence of the medial malleolus and incisura fibularis were recorded. Tibiofibular overlap, tibiofibular clear space, medial clear space, talar tilt, talocrural angle, relative fibular width and fibular position were measured.All radiographic measurements showed good to excellent intraobserver and interobserver reliability (ICCs, 0.603 to 0.949). The timing of ossification of medial malleolus and appearance of tibial incisura between boys and girls were not different. Tibiofibular clear space on mortise views, and medial clear space on AP and mortise view significantly decreased by age. Tibiofibular overlap on AP and mortise views, relative fibular width on AP view significantly increased by age. Talocrural angle, tibiofibular overlap on AP view, tibiofibular clear space on AP and mortise views, medial clear space on AP and mortise views and fibular position were significantly larger in boys than in girls. The difference in tibiofibular overlap, tibiofibular clear space and medial clear space on AP view of both sides was50% in 97.1%, 93.1%, and 97.2% of patients, respectively. The difference in tibiofibular overlap, tibiofibular clear space and medial clear space on mortise view of both sides was50% in 98.0%, 96.5%, and 100% of patients, respectively.For skeletally immature patients, the criteria for absolute radiographic values used in adults to assess distal tibiofibular syndesmosis or deltoid ligament injury cannot be applied, but comparison of both sides of ankle joint could help physicians to predict the need for additional evaluations.

Femoral derotation osteotomy (FDO) is generally reported to be excellent for correcting the hip rotation and foot progression angles in children with cerebral palsy (CP). However, it is unclear how long the favorable outcomes are maintained.This study was performed to evaluate the long-term outcomes at more than 10 years after FDO in children with CP.FDO, as part of single event multilevel surgery to improve gait function, was performed at the intertrochanteric level with the patient in the prone position. The goal of the index surgery was femoral anteversion of 15°, measured using a modified trochanteric prominence angle test intraoperatively. All patients underwent three-dimensional gait analysis preoperatively and at 1 year and over 10 years postoperatively.Thirty-four ambulatory patients (53 hips) with CP undergoing FDO were included. The mean age at surgery was 7.8 years (SD = 3.0 years) and mean follow-up duration was 12.9 years (SD = 2.7 years). The mean hip rotation decreased significantly from 9.6° preoperatively to 3.1° at 1 year postoperatively (p = 0.004), and decreased significantly to -5.9° at the final follow-up (p 0.001). The mean foot progression in stance decreased from 7.9° preoperatively to -7.4° at 1 year postoperatively (p 0.001), and was maintained at -10.9° at the final follow-up. The GDI significantly improved from 68.2 preoperatively to 83.4 1 year postoperatively (p 0.001), and was maintained at 82.3 at the final follow-up. No patients underwent revision surgery due to recurrence of rotation deformity.Proximal FDO performed in the prone position provides favorable long-term outcomes at more than 10 years postoperatively, without recurrence of rotation deformity. To avoid under-correction or recurrence due to insufficient derotation, surgeons should consider not only dynamic gait analysis findings but also the measurement of anatomic femoral anteversion during intraoperative derotation.

Calcaneal lengthening (CL) is one of the treatment options for planovalgus deformity in patients with cerebral palsy (CP). However, its indication still needs to be clarified according to the functional status of CP. The aim of this study was to investigate the radiographic outcome after CL in patients with CP and to evaluate the risk factors causing undercorrection of planovalgus deformities. We included consecutive patients with CP who underwent CL for planovalgus deformity, were followed for more than 2 years, and had preoperative and postoperative weight-bearing anteroposterior (AP) and lateral foot radiographs. Six radiographic indices were used to assess the radiographic outcome. The patient age, sex, and Gross Motor Function Classification System (GMFCS) level were evaluated as possible risk factors, and we controlled for the interaction of potentially confounding variables using multivariate analysis. A total of 44 (77 feet) patients were included in this study. The mean age of the patients at the time of surgery was 10.5±4.0 years and the mean follow-up was 5.1±2.2 years. Patients with GMFCS III/IV achieved less correction than those with GMFCS I/II in the AP talus-first metatarsal angle (P=0.001), lateral talocalcaneal angle (P=0.028), and the lateral talus-first metatarsal angle (P

Proximal femoral osteotomy has been used in cerebral palsy, Perthes disease, hip dysplasia, idiopathic femoral anteversion, and various hip diseases in children and adolescents. Conventionally, a blade plate (BP) has been used. However, the pediatric locking compression plate (LCP) has recently been applied widely. We compared the hardware-related complications of the BP and the LCP as well as the factors influencing these complications in patients who have undergone a proximal femoral osteotomy in children and adolescents. We enrolled consecutive patients aged less than or equal to 20 years who had undergone proximal femoral osteotomy with BP or LCP between May 2003 and December 2014, and who were followed up until 6 months after hardware removal. Following consensus building, hardware-related complications were identified from the patients' medical records and hip radiographs. Patient age, sex, type of plate, and Gross Motor Function Classification System (GMFCS) level in cerebral palsy patients were evaluated as possible risk factors, and a generalized estimating equation was used to assess the risk factors for hardware-related complications. A total of 417 hips from 251 patients were finally included in this study. Seven losses of fixation around the plate (five patients, 3.0%) occurred in the BP, three implant-related fractures (three patients, 3.6%) occurred in the LCP, and there was no significant difference (P=0.74). All hardware-related complications occurred in cerebral palsy patients, and the implant-related fractures occurred in patients with GMFCS IV/V. The risk of complications increased with age (P=0.002). The risk of loss of fixation around the BP is a well-known complication. However, LCP is not without hardware-related complications. The LCP provides strong stability of fixation. However, it is speculated that the LCP is related to implant-related fractures because of the stress shielding effect. Therefore, care should be exercised when using a locking plate in patients with osteoporosis, such as cerebral palsy with GMFCS IV/V. LEVEL OF EVIDENCE Therapeutic Level III.

There has been no study evaluating the change of limb alignment for patients with genu valgum. The purpose of this study was to investigate the change of limb alignments in children and adolescents with idiopathic genu valgum through evaluating distal femur, proximal tibia, and knee joint line. Consecutive children and adolescents, under the age of 18, with genu valgum were included. Mechanical tibiofemoral angle, mechanical lateral distal femoral angle, mechanical medial proximal tibia angle, and joint line convergence angle were measured. The rate of changes for each radiographic measurement were analyzed using a linear mixed model. A total of 1539 teleroentgenograms from 518 limbs of 273 individuals were included in this study. Linear mixed model showed that the change of limb alignment was significantly associated with age, but not associated with gender and laterality. The mechanical tibiofemoral angle was most valgus initially, decreasing until reaching its lowest value of 2.8° at 10 years old. The mechanical lateral distal femoral angle decreases from initial neutral alignment and increases in valgus continuously. The mechanical medial proximal tibia angle decreases from initial valgus and progresses to be neutral at around the age of 10. The joint line convergence angle decreases sharply from initial valgus alignment to 0° at the age of 5. Valgus alignment in children with idiopathic genu valgum decreases until approximately the age of 10. In younger children, the tibia and joint line contribute most to overall valgus alignment; in older children, the femur contributes the most. Based on our results, we recommend monitoring patient limb alignment until it stabilizes around the age of 10, and then carefully planning and performing corrective surgery with complete consideration of the changing bony alignment.

Although papillary thyroid cancers are known to have a relatively low risk of recurrence, several factors are associated with a higher risk of recurrence, such as extrathyroidal extension, nodal metastasis, and BRAF gene mutation. However, predicting disease recurrence and prognosis in patients undergoing thyroidectomy is clinically difficult. To detect new algorithms that predict recurrence, inductive logic programming was used in this study. A total of 785 thyroid cancer patients who underwent bilateral total thyroidectomy and were treated with radioiodine were selected for our study. Of those, 624 (79.5%) cases were used to create algorithms that would detect recurrence. Furthermore, 161 (20.5%) cases were analyzed to validate the created rules. DELMIA Process Rules Discovery was used to conduct the analysis. Of the 624 cases, 43 (6.9%) cases experienced recurrence. Three rules that could predict recurrence were identified, with postoperative thyroglobulin level being the most powerful variable that correlated with recurrence. The rules identified in our study, when applied to the 161 cases for validation, were able to predict 71.4% (10 of 14) of the recurrences. Our study highlights that inductive logic programming could have a useful application in predicting recurrence among thyroid patients.