Residual Acetabular Dysplasia at Walking Age: A Study of 470 Hips Treated With Pavlik Harness.

BACKGROUND: This study aims to report on the acetabular indices of walking age children following successful DDH treatment with Pavlik harness and investigate risk factors for residual acetabular dysplasia (RAD). METHODS: We retrospectively reviewed the data for children treated for DDH at a single centre between 2015 and 2020. Acetabular indices (AI) measured on pelvic radiographs taken at 2- and 4-year follow-up visits were referenced against age-matched and sex-matched normal data. Values ≥90th percentile were considered to represent RAD. RESULTS: A total of 305 children with 470 hips were suitable for inclusion. The mean age at treatment initiation was 7.0±4.5 weeks and mean treatment duration was 15.9±4.3 weeks. Overall, 27% and 19% of hips were found to have RAD at 2- (n=448) and 4-year (n=206) follow-up, respectively. The χ2 test for independence demonstrated that the difference in the proportion of hips with RAD at both time points was significant (P=0.032). Patients with RAD at 2 years were found to have been treated for longer (P=0.028) and had lower alpha angles on final ultrasound assessment (P<0.001). Patients with RAD at 4 years were older at initiation of treatment (P=0.041), had lower alpha angles on final ultrasound assessment (P<0.001) and were more likely to have had RAD at 2 years (P<0.001). Multivariate analysis identified lower alpha angles on final ultrasound to be predictive for RAD at 2 years (P=0.011), and presence of RAD at 2 years to be predictive for RAD at 4 years (P<0.001). CONCLUSIONS: The risk of RAD beyond walking age in children successfully treated with Pavlik harness is not negligible. However, we observed that a significant proportion of children with RAD at 2-year follow-up had spontaneously improved without any intervention. This data suggests that routine long-term radiologic follow-up of children treated with Pavlik harness is necessary, and surgical intervention to address RAD should be delayed until at least 4 years of age. LEVEL OF EVIDENCE: Level III-case-control study.

Dynamic Gait Analysis in Paediatric Flatfeet: Unveiling Biomechanical Insights for Diagnosis and Treatment.

BACKGROUND: Flatfeet in children are common, causing concern for parents due to potential symptoms. Technological advances, like 3D foot kinematic analysis, have revolutionized assessment. This review examined 3D assessments in paediatric idiopathic flexible flat feet (FFF). METHODS: Searches focused on paediatric idiopathic FFF in PubMed, Web of Science, and SCOPUS. Inclusion criteria required 3D kinematic and/or kinetic analysis during posture or locomotion, excluding non-idiopathic cases, adult feet, and studies solely on pedobarography or radiographs. RESULTS: Twenty-four studies met the criteria. Kinematic and kinetic differences between FFF and typical feet during gait were outlined, with frontal plane deviations like hindfoot eversion and forefoot supination, alongside decreased second peak vertical GRF. Dynamic foot classification surpassed static assessments, revealing varied movement patterns within FFF. Associations between gait characteristics and clinical measures like pain symptoms and quality of life were explored. Interventions varied, with orthoses reducing ankle eversion and knee and hip abductor moments during gait, while arthroereisis normalized calcaneal alignment and hindfoot eversion. CONCLUSIONS: This review synthesises research on 3D kinematics and kinetics in paediatric idiopathic FFF, offering insights for intervention strategies and further research.

Health-related Quality of Life in Idiopathic Toe Walkers: A Multicenter Prospective Cross-sectional Study.

OBJECTIVE: Despite idiopathic toe walking (ITW) being a significant source of stress and anxiety for children and parents alike, little is known about the effect on health-related quality of life (HRQoL). The primary research question for this study was "Is ITW associated with impaired HRQoL, and is the degree of equinus contracture related to the degree of impairment?" METHODS: Twelve pediatric orthopaedic centers across the United Kingdom participated in this prospective, cross-sectional observational study of children younger than 18 years with ITW. Data were collected between May 2022 and July 2022. Using a standardized, piloted proforma, data collected included: demographics, toe-walking duration, passive ankle range of motion (Silfverskiold test), associated autism spectrum disorder or attention deficit hyperactivity disorder, previous and planned treatments, and Oxford Ankle Foot Questionnaire for Children scores. Domain scores were compared with a healthy control group and correlation was made to plantarflexion contracture using standard nonparametric statistical methods. RESULTS: Data were collected from 157 children. Significant reductions in physical, school and play, and emotional domain scores were noted compared with healthy controls. A significant moderate correlation was noted between passive ankle dorsiflexion and physical domain scores. There were no significant differences in Oxford Ankle Foot Questionnaire for Children scores among patient groups by treatment. CONCLUSIONS: ITW in children is associated with an impairment in HRQoL, not only across the physical domain but also the school and play and emotional domains. The more severe the equinus contracture, the worse the physical domain scores. LEVEL OF EVIDENCE: Level II-prospective cross-sectional observational study.

Aneurysmal bone cysts: A UK wide tumor center experience.

BACKGROUND AND OBJECTIVES: This multicenter retrospective series of consecutive extra-spinal aneurysmal bone cysts aims to identify risk factors for treatment failure. METHODS: Aneurysmal bone cysts treated within seven collaborating centers with over 12-months follow-up were eligible for inclusion. Survival analyses were performed to identify variables associated with recurrence using log-rank tests and Cox proportional hazard regression. RESULTS: One hundred and fifteen (M:F 60:55) patients were included. Median age at presentation was 13 years and median follow-up was 27 months. Seventy-five patients underwent surgical curettage and 27% of these required further intervention for recurrence. Of the 30 patients who underwent biopsy with limited percutaneous curettage as initial procedure, 47% required no further treatment. Patients under 13 years (log-rank p = 0.006, HR 2.3, p = 0.011) and those treated who had limited curettage (log-rank p = 0.001, HR 2.7, p = 0.002) had a higher risk of recurrence/persistence. CONCLUSIONS: There is a high risk of recurrence following surgical treatment for aneurysmal bone cysts and this risk is higher in young patients. However, the cyst heals in a substantial number of patients who have a limited curettage at the time of biopsy.

Risk of Neurovascular Injury during Screw Fixation of Tibial Tubercle Fractures in Pediatric and Adolescent Patients.

Objective To review knee magnetic resonance imaging (MRI) scans for the analysis of the location of neurovascular structures (NVSs), and to define the risk of bicortical fixation. Methods Distances between the posterior cortex and the popliteal NVSs were measured on the MRI scans of 45 adolescents (50 knees) at 3 levels (C1: center of the proximal tibial epiphysis; C2: 10 mm distal to the physis; and C3: 20 mm distal to the physis). The NVSs located between 5 mm and 10 mm from the incision were considered in a zone of moderate risk for damage, while those less than 5 mm from the incision were considered in a zone of high risk for damage, and those more than 10 mm from the incision were considered to be in a zone of low risk for damage. The independent Student t -test was used for the comparison of the NVS distance 0with gender, skeletal maturity, and the tibial tubercle-trochlear groove (TT-TG) distance. Values of p < 0.05 were regarded as statistically significant. Results The path of the C1 screw posed an increased risk of damage to the popliteal artery and vein compared with other screw paths ( p < 0.001). The popliteal artery has a high risk of damage at the level of C1 (4.2 ± 2.2mm), and a moderate risk at C2 (9.6 ± 2.4mm), and the popliteal vein has a moderate risk at C1 (6.0 ± 2.7 mm), and a low risk at C2 and C3 (10.8 ± 3.1mm, and 12.05 ± 3.1mm respectively). The C3 position presented the lowest risk of damage to these structures ( p < 0.001). The distance between the posterior tibial cortex and the posterior tibial nerve was < 15 mm at the 3 levels analyzed (C1: 11.0 ± 3.7 mm; C2: 13.1 ± 3.8 mm; and C3: 13 ± 3.9 mm). Conclusions The present study clarifies that the popliteal vessels are at risk of injury during tibial tubercle screw fixation, particularly when drilling the proximal tibial epiphysis. Monocortical drilling and screw fixation are recommended for the surgical treatment of tibial tubercle fractures. Level of Evidence III Diagnostic study.

Using surface markers to describe the kinematics of the medial longitudinal arch.

BACKGROUND: Static and dynamic assessment of the medial longitudinal arch (MLA) is an essential aspect for measuring foot function in both clinical and research fields. Despite this, most multi-segment foot models lack the ability to directly track the MLA. This study aimed to assess various methods of MLA assessment, through motion capture of surface markers on the foot during various activities. METHODS: Thirty general population participants (mean age 20 years) without morphological alterations to their feet underwent gait analysis. Eight measures, each representing a unique definition of the MLA angle using either real only, or both real and floor-projected markers, were created. Participants performed tasks including standing, sitting, heel lift, Jack's test and walking, and had their Arch Height Index (AHI) measured using callipers. Multiple-criteria decision analysis (MCDA) with 10 criteria was utilised for selecting the optimal measure for dynamic and static MLA assessment. RESULTS: In static tasks, the standing MLA angle was significantly greater in all measures but one when compared to sitting, Jack's test and heel lift. The MLA angle in Jack's test was significantly greater than in heel lift in all measures. Across the compared dynamic tasks, significant differences were noted in all measures except one for foot strike in comparison to 50% gait cycle. All MLA measures held significant inverse correlations with MLA measured from static and dynamic tasks. Based on MCDA criteria, a measure comprising the first metatarsal head, fifth metatarsal base, navicular and heel markers was deemed the best for MLA assessment. SIGNIFICANCE: This study aligns with the current literature recommendations for the use of a navicular marker for characterising the MLA. It contrasts with previous recommendations and advocates against the use of projected markers in most situations.

Evaluation of the Optimal Femoral Fixation Site for Medial Patellofemoral Ligament Reconstruction in the Skeletally Immature Patient.

The aim of this study was to assess which femoral fixation site, distal to the physis, most closely emulates the native medial patellofemoral ligament (nMPFL) length relationship in the pediatric knee. Lateral knee radiographs were taken incrementally, from 0° to 120° of flexion. The femoral origin of the nMPFL and 3 other MPFL femoral fixation sites distal to the physis were identified (P1, 1 cm distal to physis along the posterior femoral cortex; P2, 2 cm distal to physis along the posterior femoral cortex; P3, 1 cm distal and 1 cm anterior). Virtual MPFL lengths were measured from all sites. Measurement reliability was assessed using intraclass correlation coefficients. Primary comparison between simulated MPFL length at native and femoral fixation sites was made using a repeated measures analysis of variance at 30° flexion. Bivariate Pearson correlation was used to assess the relationship between fixation sites and nMPFL through the range of motion (alpha=0.05). The intra-class correlation coefficient for intraobserver reliability of MPFL length measurement was excellent. Analysis of variance showed virtual MPFL lengths from proposed femoral fixation sites at 30° were significantly different from nMPFL length (P<.01). The P1 MPFL had the least difference in means compared with nMPFL (-2.6±1.8 mm). Correlational analysis showed that P1 MPFL had the closest relationship with nMPFL compared with other femoral fixation sites (R=0.91, P<.01). The P1 MPFL had the length change most comparable to that of nMPFL (23.9±3.1 mm vs 13.3±2.85 mm) compared with the other simulated MPFLs. Femoral graft fixation site 1 cm distal to the physis in the lateral view along the posterior femoral cortex closely represents the length relationship of the nMPFL. [Orthopedics. 2023;46(2):108-113.].

Risk of Neurovascular Injury during Screw Fixation of Tibial Tubercle Fractures in Pediatric and Adolescent Patients / Risco de lesão neurovascular durante a fixação com parafuso de fraturas da tuberosidade da tíbia em pacientes pediátricos e adolescentes

Abstract Objective To review knee magnetic resonance imaging (MRI) scans for the analysis of the location of neurovascular structures (NVSs), and to define the risk of bicortical fixation. Methods Distances between the posterior cortex and the popliteal NVSs were measured on the MRI scans of 45 adolescents (50 knees) at 3 levels (C1: center of the proximal tibial epiphysis; C2: 10 mm distal to the physis; and C3: 20 mm distal to the physis). The NVSs located between 5 mm and 10 mm from the incision were considered in a zone of moderate risk for damage, while those less than 5 mm from the incision were considered in a zone of high risk for damage, and those more than 10 mm from the incision were considered to be in a zone of low risk for damage. The independent Student t-test was used for the comparison of the NVS distance 0with gender, skeletal maturity, and the tibial tubercle-trochlear groove (TT-TG) distance. Values of p < 0.05 were regarded as statistically significant. Results The path of the C1 screw posed an increased risk of damage to the popliteal artery and vein compared with other screw paths (p < 0.001). The popliteal artery has a high risk of damage at the level of C1 (4.2 ± 2.2mm), and a moderate risk at C2 (9.6 ± 2.4mm), and the popliteal vein has a moderate risk at C1 (6.0 ± 2.7 mm), and a low risk at C2 and C3 (10.8 ± 3.1mm, and 12.05 ± 3.1mm respectively). The C3 position presented the lowest risk of damage to these structures (p < 0.001). The distance between the posterior tibial cortex and the posterior tibial nerve was < 15 mm at the 3 levels analyzed (C1: 11.0 ± 3.7 mm; C2:13.1 ± 3.8 mm; and C3:13 ± 3.9 mm). Conclusions The present study clarifies that the popliteal vessels are at risk of injury during tibial tubercle screw fixation, particularly when drilling the proximal tibial epiphysis. Monocortical drilling and screw fixation are recommended for the surgical treatment of tibial tubercle fractures. Level of Evidence III Diagnostic study.

Resumo Objetivo Revisar estudos de ressonância magnética (RM) do joelho para análise da localização das estruturas neurovasculares (ENVs) e definição do risco de fixação bicortical. Métodos As distâncias entre o córtex posterior e as ENVs poplíteas foram medidas nas RMs de 45 adolescentes (50 joelhos) em 3 níveis (C1: centro da epífise proximal da tíbia; C2:10 mm distalmente à fise e C3: 20 mm distalmente à fise). Considerou-se que as ENVs entre 5mme10mmda incisão estavam na zona de risco moderado de lesão, as ENVs a menos de 5 mm da incisão, na zona de alto risco de lesão, e as ENVs a mais de 10 mm da incisão, na zona de baixo risco de lesão. O teste t de Student independente foi usado para comparar a distância até as ENVs com o gênero, a maturidade esquelética e a distância entre a tuberosidade tibial e a garganta (fundo) da tróclea (TT-GT). Valores de p < 0,05 foram considerados estatisticamente significativos. Resultados A trajetória do parafuso em C1 apresentou maior risco de lesão à artéria e à veia poplítea em comparação com outras trajetórias (p < 0,001). A artéria poplítea apresenta risco de lesão alto em C1 (4,2 ± 2,2 mm) e moderado em C2 (9,6 ± 2,4 mm), e a veia poplítea tem risco moderado em C1 (6,0±2,7 mm) e baixo em C2 e C3 (10,8±3,1 mm e 12,05±3,1mm, respectivamente). A posição C3 apresentou o menor risco de lesão dessas estruturas (p < 0,001). A distância entre o córtex tibial posterior e o nervo tibial posterior foi inferior a 15 mm nos 3 níveis analisados (C1: 11,0±3,7mm; C2: 13,1±3,8 mm; e C3: 13±3,9mm). Conclusões Este estudo esclarece que os vasos poplíteos correm risco de lesão durante a fixação do parafuso na tuberosidade tibial, principalmente durante a perfuração da epífise proximal da tíbia. A perfuração monocortical e a fixação com parafusos são recomendadas para o tratamento cirúrgico das fraturas da tuberosidade tibial. Nível de Evidência III Estudo diagnóstico.

Percutaneous Strain Reduction Screws Are a Reproducible Minimally Invasive Method to Treat Long Bone Nonunion.

OBJECTIVES: (1) Evaluate whether initial results from percutaneous treatment of nonunion are reproducible (2) Estimate the relative cost of percutaneous treatment of nonunion versus traditional methods. DESIGN: Retrospective multicentre case series. SETTING: Four Level 1 trauma centers. PATIENTS/PARTICIPANTS: Fifty-one patients (34 men and 17 women) with a median age of 51 years (range 14-81) were treated for nonunion at a median of 10 months (range 4-212) from injury. INTERVENTION: Percutaneous strain reduction screws (PSRS). MAIN OUTCOME MEASURED: Union rates and time to union were compared for patients treated in the developing institution versus independent units as well as with previously published results. RESULTS: Forty-five (88%) patients achieved union at a median time of 5.2 months (range 1.0-24.7) confirming the previously published results for this technique. Comparable results were seen between the developing institution and independent units. No patients experienced adverse events beyond failure to achieve union. PSRS seems to offer savings of between £3177 ($4416) to £11,352 ($15,780) per case compared with traditional methods of nonunion surgery. CONCLUSIONS: PSRS is a safe, efficacious treatment for long bone nonunion and may be more cost-effective than traditional nonunion treatment methods. The promising initial results of this technique have now been replicated outside of the developing institution. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Construction and validation of sham insoles used in clinical trials: A systematic review.

BACKGROUND: Insoles are commonly prescribed to treat pathologies in a variety of patient groups; however, there is limited evidence to guide clinical decision-making. A well-validated sham insole is critical to conducting a double-blind placebo-controlled trial. OBJECTIVES: The aims were to establish: (1) How are sham insoles constructed? (2) What measures are undertaken to ensure adequate blinding? (3) What methods are used to validate the biomechanical effects? STUDY DESIGN: A systematic search of the methodology of level I-II therapeutic evidence. METHODS: Searches were conducted in MEDLINE, Embase, Cumulative Index of Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Trials. Inclusion criteria were placebo-controlled clinical trials, sham insoles used, treatment insoles alter biomechanics, treatment insoles meet the ISO definition of foot orthotics, sham and treatment insoles tested in normal walking, and article available in English. RESULTS: The search generated 270 results. Twenty-four trials were included. 19% of sham insoles were described sufficiently to be replicated. The most common sham construction characteristics were full length, ethylene-vinyl acetate material, and flat insoles. 58% of studies were double-blinded; however, many did not describe any blinding methods. There is evidence that blinding the intervention details and a similar insole appearance is effective to blind participants. 13% of studies included a shoe-only condition to allow assessment of the biomechanical effects of sham insoles. CONCLUSIONS: There is inconsistent construction, blinding, and biomechanical validation of sham insoles. This casts a substantial doubt on the quality and reliability of the evidence base to support the prescription of insoles.

Locked Intramedullary Nailing versus Compression Plating for Stable Ulna Fractures: A Comparative Study.

BACKGROUND: Isolated ulna shaft fractures (USFs) are a relatively uncommon, but significant, injury. For unstable USF treatment, open reduction and internal fixation (ORIF) is the gold standard, while for stable USFs several procedures were described. The aim of this study is to compare the outcomes in patients with stable USFs treated by either ORIF or intramedullary nail (IMN). METHODS: According to their surgical treatment, 23 eligible USF-affected patients were divided into ORIF (14 subjects) and IMN (nine subjects) groups. The subjects underwent postoperative clinical follow-up at 1, 3, 6, and 12 months, which included calculation of the Disabilities of the Arm, Shoulder and Hand (DASH) score and radiological follow-up. Time to union, time to return to sporting and occupational activities, duration of physical therapy, and surgical complications were recorded. RESULTS: DASH scores improved in both groups at the 6-month follow-up (p < 0.001). The IMN cohort recorded better DASH scores at the 1- and 3-month follow-ups, while similar results were reported at the 6- and 12-month follow-ups. Earlier fracture union (p = 0.001) and return to sporting activities and work (p = 0.002) were seen in the IMN group, compared with the ORIF group. No complications were observed in the IMN group. CONCLUSIONS: The surgical treatment of isolated USF results in excellent functional and radiographic outcomes. IMN may be preferable, compared with ORIF, due to its faster recovery time, expedited union, and reduced likelihood of complications.

Efficacy of treatment interventions for primary aneurysmal bone cysts: a systematic review.

AIMS: Aneurysmal bone cysts (ABCs) are locally aggressive lesions typically found in the long bones of children and adolescents. A variety of management strategies have been reported to be effective in the treatment of these lesions. The purpose of this review was to assess the effectiveness of current strategies for the management of primary ABCs of the long bones. METHODS: A systematic review of the published literature was performed to identify all articles relating to the management of primary ABCs. Studies required a minimum 12-month follow-up and case series reporting on under ten participants were not included. RESULTS: A total of 28 articles meeting the eligibility criteria were included in this review, and all but one were retrospective in design. Due to heterogeneity in study design, treatment, and outcome reporting, data synthesis and group comparison was not possible. The most common treatment option reported on was surgical curettage with or without a form of adjuvant therapy, followed by injection-based therapies. Of the 594 patients treated with curettage across 17 studies, 86 (14.4%) failed to heal or experienced a recurrence. Similar outcomes were reported for 57 (14.70%) of the 387 patients treated with injection therapy across 12 studies. Only one study directly compared curettage with injection therapy (polidocanol), randomizing 94 patients into both treatment groups. This study was at risk of bias and provided low-quality evidence of a lack of difference between the two interventions, reporting success rates of 93.3% and 84.8% for injection and surgical treatment groups, respectively. CONCLUSION: While both surgery and sclerotherapy are widely implemented for treatment of ABCs, there is currently no good quality evidence to support the use of one option over the other. There is a need for prospective multicentre randomized controlled trials (RCTs) on interventions for the treatment of ABCs. Cite this article: Bone Jt Open 2021;2(2):125-133.

The lateral edge and sourcil acetabular indices for surgical decision-making in developmental dysplasia of the hip.

PURPOSE: The acetabular index (AI) is a radiographic measure that guides surgical decision-making in developmental dysplasia of the hip (DDH). Two AI measurement methods are described; to the lateral edge of the acetabulum (AI-L) and to the lateral edge of the sourcil (AI-S). The purpose of this study was to determine the level of agreement between AI-L and AI-S on the diagnosis and degree of acetabular dysplasia in DDH. METHODS: A total of 35 patients treated for DDH with Pavlik harness were identified. The AI-L and AI-S were measured on radiographs (70 hips) at two and five years of age. AI-L and AI-S were then transformed relative to published normative data (tAI-L and tAI-S). Bland-Altman plots, linear regression and heat mapping were used to evaluate the agreement between tAI-L and tAI-S. RESULTS: There was poor agreement between tAI-S and tAI-L on the Bland-Altman plots with wide limits of agreement and no proportional bias. The two AI measurements were in agreement as to the presence and severity of dysplasia in only 63% of hips at two years of age and 81% at five years of age, leaving the remaining hips classified as various combinations of normal, mildly and severely dysplastic. CONCLUSION: AI-L and AI-S have poor agreement on the presence or degree of acetabular dysplasia in DDH and cannot be used interchangeably. Clinicians are cautioned to prudently evaluate both measures of AI in surgical decision-making. LEVEL OF EVIDENCE: I.

Surgical treatment of tarsal coalitions in children and adolescents.

A tarsal coalition is an abnormal connection between two or more tarsal bones caused by failure of mesenchymal segmentation.The two most common tarsal coalitions are calcaneonavicular coalition (CNC) and talocalcaneal coalition (TCC). Both CNC and TCC can be associated with significant foot and ankle pain and impaired quality of life; there may also be concomitant foot and ankle deformity.Initial, non-operative management for symptomatic tarsal coalition commonly fails, leaving surgical intervention as the only recourse.The focus of this article is to critically describe the variety of methods used to surgically manage CNC and TCC. In review of the pertinent literature we highlight the ongoing treatment controversies in this field and discuss new innovations.The evidence-based algorithmic approach used by the authors in the management of tarsal coalitions is illustrated alongside some clinical pearls that should help surgeons treating this common, and at times complex, condition. Cite this article: EFORT Open Rev 2020;5:80-89. DOI: 10.1302/2058-5241.5.180106.

Comparison of the hindfoot axes of a multi-segment foot model to the underlying bony anatomy.

Musculoskeletal models used in gait analysis require coordinate systems to be identified for the body segments of interest. It is not obvious how hindfoot (or rearfoot) axes defined by skin-mounted markers relate to the anatomy of the underlying bones. The aim of this study was to compare the marker-based axes of the hindfoot in a multi-segment foot model to the orientations of the talus and calcaneus as characterized by their principal axes of inertia. Twenty adult females with no known foot deformities had radio-opaque markers placed on their feet and ankles at the foot model marker locations. CT images of the feet were acquired as the participants lay supine with their feet in a semi-weight bearing posture. The spatial coordinates of the markers were obtained from the images and used to define the foot model axes. Segmented masks of the tali and calcanei were used to create 3D bone models, from which the principal axes of the bones were obtained. The orientations of the principal axes were either within the range of typical values reported in the imaging literature or differed in ways that could be explained by variations in how the angles were defined. The model hindfoot axis orientations relative to the principal axes of the bones had little bias but were highly variable. Consideration of coronal plane hindfoot alignment as measured clinically and radiographically suggested that the model hindfoot coordinate system represents the posterior calcaneal tuberosity, rather than the calcaneus as a whole.

Juvenile osteochondritis dissecans (JOCD) of the knee: current concepts review.

Juvenile osteochondritis dissecans (JOCD) is a joint disorder of the subchondral bone and articular cartilage that affects skeletally immature patients.The aetiology of JOCD is unknown and the natural history is poorly characterized in part due to inconsistent and largely retrospective literature.Most OCD in children and adolescents presents as a stable lesion amenable to non-operative treatment or minimally invasive drilling. However, unstable forms can require a more aggressive approach.This article reviews the most recent literature available and focuses on the pathophysiology, diagnosis and treatment of JOCD of the knee. Cite this article: EFORT Open Rev 2019;4:201-212. DOI: 10.1302/2058-5241.4.180079.

Percutaneous Strain Reduction Screws-A Safe and Simple Surgical Option for Problems With Bony Union. A Technical Trick.

This article describes percutaneous strain reduction screws, a technical trick, to provide effective stability in a simple manner and at low cost. Percutaneous strain reduction screws are an option when a surgeon has decided that further intervention is indicated for a fracture that has not united.