Risk Factor Analysis for Growth Arrest in Paediatric Physeal Fractures-A Prospective Study.

Background: Fractures through the physis account for 18-30% of all paediatric fractures, leading to growth arrest in up to 5.5% of cases. We have limited knowledge to predict which physeal fractures result in growth arrest and subsequent deformity or limb length discrepancy. The purpose of this study is to identify factors associated with physeal growth arrest to improve patient outcomes. Methods: This prospective cohort study was designed to develop a clinical prediction model for growth arrest after physeal injury. Patients ≤ 18 years old presenting within four weeks of injury were enrolled if they had open physes and sustained a physeal fracture of the humerus, radius, ulna, femur, tibia or fibula. Patients with prior history of same-site fracture or a condition known to alter bone growth or healing were excluded. Demographic data, potential prognostic indicators, and radiographic data were collected at baseline, during healing, and at one- and two-years post-injury. Results: A total of 332 patients had at least six months of follow-up or a diagnosis of growth arrest within six months of injury. In a comparison analysis, patients who developed growth arrest were more likely to be older (12.8 years vs. 9.4 years) and injured on the right side (53.0% vs. 45.7%). Initial displacement and angulation rates were higher in the growth arrest group (59.0% vs. 47.8% and 47.0% vs. 38.8%, respectively), but the amount of angulation was similar (27.0° vs. 28.4°). Rates of growth arrest were highest in distal femoral fractures (86%). Conclusions: The incidence of growth arrest in this patient population appears higher than the past literature reports at 30.1%. However, there may be variances in diagnostic criteria for growth arrest, and the true incidence may be lower. A number of patients were approaching skeletal maturity, and any growth arrest is likely to have less clinical significance in these cases. Further prospective long-term follow-up is required to determine risk factors, incidence, and true clinical impact of growth arrest when it does occur.

Morquio B disease: a case report.

Mucopolysaccharidosis IV type B, or Morquio B disease (MBD), is an autosomal recessive disorder caused by a genetic mutation in GLB1 gene encoding for ß-galactosidase on chromosome 3p22.33. ß-galactosidase deficiency can result in two different conditions, GM1 gangliosidosis and MBD, of which MBD has a milder phenotype and presents later in life with keratan sulfate accumulation in the retina and cartilage. In this case report, we present a patient diagnosed with MBD at the age of 5 after initially presenting with Morquio dysostosis multiplex and characteristic radiographic findings. Genetic testing confirmed that the patient has ß-galactosidase deficiency due to mutation W273l/N484K on GLB1 gene. The patient exhibited elevated mucopolysaccharide levels in urine at 18 mg/mmol and demonstrated an abnormal band pattern of urine oligosaccharides on electrophoresis. The activity of ß-galactosidase in his white blood cells was reduced to 12.3 nmol/h/mg protein. At the time of diagnosis, the patient did not present with gait and ambulation issues, but his ability to walk progressively deteriorated in his adolescence as a result of instability and pain in the ankle, knee, and hip joints, accompanied by a global decrease in muscle strength. This case report is the first in the literature to provide an in-depth exploration of the orthopedic treatment and follow-up received by a young adolescent with MBD to provide symptom relief and improve walking ability.

Investigating microstructure evolution in block copolymer membranes.

Block copolymer self-assembly in conjunction with nonsolvent-induced phase separation (SNIPS) has been increasingly leveraged to fabricate integral-asymmetric membranes. The large number of formulation and processing parameters associated with SNIPS, however, has prevented the reliable construction of high performance membranes. In this study, we apply dynamical self-consistent field theory to model the SNIPS process and investigate the effect of various parameters on the membrane morphology: solvent selectivity, nonsolvent selectivity, initial film composition, and glass transition composition. We examine how solvent selectivity and concentration of polymers in the film impact the structure of micelles that connect to form the membrane matrix. In particular, we find that preserving the order in the surface layer and forming a connection between the supporting and surface layer are nontrivial and sensitive to each parameter studied. The effect of each parameter is discussed, and suggestions are made for successfully fabricating viable block copolymer membranes.

Fully Automated Analysis of the Anatomic and Mechanical Axes From Pediatric Standing Lower Limb Radiographs Using Convolutional Neural Networks.

BACKGROUND: Lower limb alignment is the quantification of a set of parameters that are commonly measured radiographically to test for and track a wide range of skeletal pathologies. Determining limb alignment is a commonly performed yet laborious task in the pediatric orthopaedic setting and is therefore an interesting goal for automation. METHODS: We employ a machine learning approach using convolutional neural networks (CNNs) to segment pediatric weight-bearing lower limb radiographs. The results are then used with custom Matlab code to extract anatomic landmarks and to determine lower limb alignment parameters. RESULTS: Measurements obtained from the automated workflow proposed here were compared with manual measurements performed by orthopaedic surgery fellows. Mechanical axis deviation was determined within a mean of 2.02 mm. Lateral distal femoral angle and medial proximal tibial angle were determined with a mean deviation of 1.73 and 2.90 degrees, respectively. The calculation speed for the full set of mechanical and anatomic axis parameters was found to be ~2 seconds per radiograph. CONCLUSIONS: The CNN-based approach proposed in this work was shown to produce results comparable to orthopaedic surgery fellows at fast calculation speed. Although further work is needed to validate these results against radiographs and measurements from other centers, we see this as a promising start and a functional path that can be employed in further research. CLINICAL RELEVANCE: CNNs are a promising approach to automating commonly performed, repetitive tasks, especially those pertaining to image processing. The time savings are particularly important in clinical research applications where large sets of radiographs are routinely available and require analysis. With further development of these algorithms, we anticipate significantly improved agreement with expert-measured results and the calculation speed.

Synchronization and Clustering in Complex Quadratic Networks.

Synchronization and clustering are well studied in the context of networks of oscillators, such as neuronal networks. However, this relationship is notoriously difficult to approach mathematically in natural, complex networks. Here, we aim to understand it in a canonical framework, using complex quadratic node dynamics, coupled in networks that we call complex quadratic networks (CQNs). We review previously defined extensions of the Mandelbrot and Julia sets for networks, focusing on the behavior of the node-wise projections of these sets and on describing the phenomena of node clustering and synchronization. One aspect of our work consists of exploring ties between a network's connectivity and its ensemble dynamics by identifying mechanisms that lead to clusters of nodes exhibiting identical or different Mandelbrot sets. Based on our preliminary analytical results (obtained primarily in two-dimensional networks), we propose that clustering is strongly determined by the network connectivity patterns, with the geometry of these clusters further controlled by the connection weights. Here, we first explore this relationship further, using examples of synthetic networks, increasing in size (from 3, to 5, to 20 nodes). We then illustrate the potential practical implications of synchronization in an existing set of whole brain, tractography-based networks obtained from 197 human subjects using diffusion tensor imaging. Understanding the similarities to how these concepts apply to CQNs contributes to our understanding of universal principles in dynamic networks and may help extend theoretical results to natural, complex systems.

Inter- and Intra-rater Reliability of the Checketts' Grading System for Pin-site Infections across All Skin Colours.

The Checketts' grading system (CGS) is the only classification that provides both a description of how to visually grade the infection and the appropriate course of treatment. There are no studies on the reliability of this system nor on whether skin colour can influence applicability. This study aims to determine the inter-rater and intra-rater reliability of the CGS to assess whether this scale could be used as a universal grading system across all skin colours. A survey consisting of 134 anonymised photographs of pin-site infections was sent out to orthopaedic surgeons specialising in limb lengthening and reconstruction and to patients or carers of individuals who had external fixators. For each photograph, the participants were asked to grade the infection using the CGS, rate their confidence in their chosen grade on a Likert scale and assign a treatment option. The participants were supplied with the CGS at the beginning of the survey, after the 45th and 90th photographs. The inter-rater reliability of the CGS between the surgeons, expressed as an intraclass correlation coefficient (ICC), was poor-to-moderate at both time points (ICC = 0.56 for baseline survey and ICC = 0.48 for follow-up). This was similar for the patient or caretaker group. There was a lower inter-rater reliability for grading of dark skin as opposed to light skin by surgeons but not for patients or caretakers. The inter-rater reliability of treatment decisions between the surgeons was poor at both time points (kappa = 0.30 and 0.22) with similar inter-rater reliability for dark (kappa = 0.26 and 0.23) compared with light skin (kappa = 0.29 and 2.6). This was similar for the patient or caretaker group. The surgeons' confidence (Table 4) in grading was low (median = 1). The patient or caretaker group's confidence in their grading was modest (median = 2). The reliability of the CGS as assessed here demonstrates poor-to-moderate inter-rater reliability which makes interpretation of published pin site infection rates using this scale difficult. The design of new grading systems will need to consider skin colour to reduce inequities in medical decision-making. How to cite this article: Groenewoud R, Chhina H, Bone J, et al. Inter- and Intra-rater Reliability of the Checketts' Grading System for Pin Site Infections across All Skin Colours. Strategies Trauma Limb Reconstr 2023;18(1):2-6.

Profiling the Biophysical Developability Properties of Common IgG1 Fc Effector Silencing Variants.

Therapeutic antibodies represent the most significant modality in biologics, with around 150 approved drugs on the market. In addition to specific target binding mediated by the variable fragments (Fvs) of the heavy and light chains, antibodies possess effector functions through binding of the constant region (Fc) to Fcγ receptors (FcγR), which allow immune cells to attack and kill target cells using a variety of mechanisms. However, for some applications, including T-cell-engaging bispecifics, this effector function is typically undesired. Mutations within the lower hinge and the second constant domain (CH2) of IgG1 that comprise the FcγR binding interface reduce or eliminate effector function ("Fc silencing") while retaining binding to the neonatal Fc receptor (FcRn), important for normal antibody pharmacokinetics (PKs). Comprehensive profiling of biophysical developability properties would benefit the choice of constant region variants for development. Here, we produce a large panel of representative mutations previously described in the literature and in many cases in clinical or approved molecules, generate select combinations thereof, and characterize their binding and biophysical properties. We find that some commonly used CH2 mutations, including D265A and P331S, are effective in reducing binding to FcγR but significantly reduce stability, promoting aggregation, particularly under acidic conditions commonly employed in manufacturing. We highlight mutation sets that are particularly effective for eliminating Fc effector function with the retention of WT-like stability, including L234A, L235A, and S267K (LALA-S267K), L234A, L235E, and S267K (LALE-S267K), L234A, L235A, and P329A (LALA-P329A), and L234A, L235E, and P329G (LALE-P329G).

Impact of hierarchical water dipole orderings on the dynamics of aqueous salt solutions.

Ions exhibit highly ion-specific complex behaviours when solvated in water, which remains a mystery despite the fundamental importance of ion solvation in nature, science, and technology. Here we explain these ion-specific properties by the ion-induced hierarchical dipolar, translational, and bond-orientational orderings of ion hydration shell under the competition between ion-water electrostatic interactions and inter-water hydrogen bonding. We first characterise this competition by a new length λHB(q), explaining the ion-specific effects on solution dynamics. Then, by continuously tuning ion size and charge, we find that the bond-orientational order of the ion hydration shell highly develops for specific ion size and charge combinations. This ordering drastically stabilises the hydration shell; its degree changes the water residence time around ions by 11 orders of magnitude for main-group ions. These findings are fundamental to ionic processes in aqueous solutions, providing a physical principle for electrolyte design and application.

Danish Linguistic Validation and Cultural Adaptation of the LIMB-Q Kids.

(1) Background: Lower Limb deformities include many conditions where pain and physical limitations negatively impact the health-related quality of life (HRQL) of children. The ideal way to assess this impact is by using a Patient Reported Outcome Measure (PROM). Such a condition-specific PROM is under development, called LIMB-Q Kids. This study aimed to perform a translation and cultural adaption (TCA) of the LIMB-Q Kids for use in Danish-speaking children. (2) Methods: TCA guidelines established by the World Health Organization (WHO) and the Professional Society for Health Economics and Outcomes Research (ISPOR) were followed. This process consisted of two independent forward translations, a reconciliation meeting, a backward translation with an assessment, an expert meeting, cognitive interviews with patients, editing based on the interviews, and proofreading. (3) Results: The TCA process contributed to the Danish version of LIMB-Q Kids. The reconciliation meeting resulted in a reconciled Danish version. The revision of the backward translation led to 16 corrections, and after the expert panel meeting, 26 changes were made. Twelve cognitive interviews led to nine changes, which were validated by two further interviews. Proofreading led to no further comments. (4) Conclusions: The TCA process led to a linguistically validated and culturally adapted Danish version of LIMB-Q Kids. This version is being used in the international field test study.

Multiscale modeling of solute diffusion in triblock copolymer membranes.

We develop a multiscale simulation model for diffusion of solutes through porous triblock copolymer membranes. The approach combines two techniques: self-consistent field theory (SCFT) to predict the structure of the self-assembled, solvated membrane and on-lattice kinetic Monte Carlo (kMC) simulations to model diffusion of solutes. Solvation is simulated in SCFT by constraining the glassy membrane matrix while relaxing the brush-like membrane pore coating against the solvent. The kMC simulations capture the resulting solute spatial distribution and concentration-dependent local diffusivity in the polymer-coated pores; we parameterize the latter using particle-based simulations. We apply our approach to simulate solute diffusion through nonequilibrium morphologies of a model triblock copolymer, and we correlate diffusivity with structural descriptors of the morphologies. We also compare the model's predictions to alternative approaches based on simple lattice random walks and find our multiscale model to be more robust and systematic to parameterize. Our multiscale modeling approach is general and can be readily extended in the future to other chemistries, morphologies, and models for the local solute diffusivity and interactions with the membrane.

Early Investigation and Bracing in DDH Impacts Maternal Wellbeing and Breastfeeding.

BACKGROUND: The outcomes of Pavlik Harness (PH) management for Developmental Dysplasia of the Hip (DDH) are equivalent regardless of the initiation timing, if it is within the first 6 weeks of life. A PH may be a physical barrier to breastfeeding, which is important for nutrition, immunity, and normal child development. The diagnosis of DDH and early management with a PH may also negatively affect the maternal psychosocial wellbeing and the infant-maternal relationship. The purpose of this study is to investigate the impact of the diagnosis of DDH and the management with a PH has on maternal wellbeing and maintenance of breastfeeding, compared with being screened for but not diagnosed with DDH. METHODS: A retrospective cohort of the mothers of infants who were diagnosed with DDH and treated with a PH brace was compared with the mothers of infants who were screened for DDH only. The Hip Worries Inventory and Edinburgh Postnatal Depression Scale were completed by the mothers in both groups. The PH group also completed an in-house questionnaire specific to PH and breastfeeding. RESULTS: Eighty completed surveys were included, 50 from the treatment group. The mean age of the PH initiation was 6.2 weeks. The modified Hip Worries Inventory score was higher in the treatment group, with a mean difference (MD) of 9.7 out of 50 (95% confidence interval, CI, 6.8, 12.5). The MD of the Edinburgh Postnatal Depression Scale was 2.0 out of 30 (CI -0.5, 4.5). Although there was no difference in the breastfeeding ease before and after the PH initiation (MD-0.2, CI-0.7, 0.2), 83% of mothers found breastfeeding more difficult with a PH and 11% of mothers stopped breastfeeding earlier than planned because of the PH. CONCLUSIONS: Mothers of infants with DDH worry more about their child's hips and the PH. Screening alone may contribute to maternal psychological dejection and negative thoughts. The presence of a PH makes breastfeeding more difficult. LEVEL OF EVIDENCE: Retrospective comparative study, level III.

Modeling Microstructure Formation in Block Copolymer Membranes Using Dynamical Self-Consistent Field Theory.

Block copolymers have attracted recent interest as candidate materials for ultrafiltration membranes, due to their ability to form isoporous integral-asymmetric membranes by the combined processes of self-assembly and nonsolvent-induced phase separation (SNIPS). However, the dependence of surface layer and substructure morphologies on the processing variables associated with SNIPS is not well understood nor is the interplay between microphase and macrophase separation in block copolymers undergoing such coagulation. Here, we use dynamical self-consistent field theory to simulate the microstructure evolution of block copolymer films during SNIPS and find that such films form the desired sponge-like asymmetric porous substructure only if the solvent and nonsolvent have opposite block selectivities and that otherwise they form a dense nonporous microphase-separated film. Our results could have important implications for the choices of solvent and nonsolvent in the processing of block copolymer membranes.

Multimodal Analgesia for Paediatric Patients Undergoing Lower Limb Reconstruction with External Fixators: A Prospective Case Series of Post-operative Pain and Functional Goals.

Aim: Limb reconstruction with external fixators requires appropriate pain management to promote effective analgesia and healing while minimising adverse events of the analgesic technique used. The objective of this prospective case series was to evaluate a multimodal analgesia regimen designed to reduce opioid requirements and hence reduce the opioid-related side effect profile. Materials and methods: A prospective cohort of patients undergoing lower limb reconstruction surgery (LRS) were managed through an evidence-informed multimodal analgesia guideline (MMAG), including acetaminophen, pregabalin, dexmedetomidine, IV lidocaine, and opioids. Outcome measures included intraoperative and post-operative opioid administration, post-operative pain scores, time to achieve mobilisation milestones, and post-operative complications. Surveys were conducted to obtain patient reported experiences. Results: 26 patients were included in this prospective case series. 110.59 (84.29, 162.13) (median, interquartile range) µg/kg/hr intraoperative IV morphine equivalent opioids were administered. In the first 48 hours post-operatively, patients received 11.49 (6.41, 19.35) µg/kg/hr of IV morphine equivalent dose. Median level of pain (0-10) in the first 48 post-operative hours was 2 (1, 2). Patients achieved mobilisation. And 19/20 patients surveyed reported 'yes' to having effective pain management; 17/20 patients had no unwanted side effects associated with analgesia medications. There were no cases of compartment syndrome. Conclusion: This multimodal analgesia regime applied to patients undergoing lower LRS with external fixators demonstrates the feasibility of this analgesic regimen which revealed effective pain control, early mobilisation, with minimal side effects, but warrants further study. Clinical significance: This study provides valuable evidence that this standardised multimodal anaesthesia and analgesia regimen is feasible, offers adequate post-operative comfort and encourages early mobilization while minimising opioid use and adverse events in a paediatric LRS population at our institution. How to cite this article: Wang AWT, Chhina H, Cooper A. Multimodal Analgesia for Paediatric Patients Undergoing Lower Limb Reconstruction with External Fixators: A Prospective Case Series of Post-operative Pain and Functional Goals. Strategies Trauma Limb Reconstr 2023;18(3):140-147.

LIMB-Q Kids-German Translation and Cultural Adaptation.

(1) Purpose: Lower limb deformities can have a severe impact on health-related quality of life (HRQL). LIMB-Q Kids is a new patient-reported outcome measure (PROM) aiming to elucidate the experience of 8-18-year-old patients before, during and after treatment, and to measure the different aspects of HRQL. The aim of this study was to translate and culturally adapt LIMB-Q Kids to German. (2) Methods: The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines were followed. Three forward translations, a backward translation, an expert panel meeting with eight participants, and twenty cognitive debriefing interviews led to the final German version of LIMB-Q Kids. (3) Results: In the forward translations, 4/159 items were difficult to translate, and 2/159 items in the backward translation differed from the original English version. Cognitive debriefing interviews with 20 patients identified 7/159 items that were difficult to comprehend/answer, and 2 of these items were changed. (4) Conclusions: Lower limb deformities can have a great impact on children, and it is important to measure and consider the impact on HRQL. In order to be able to use PROMs in different countries, conceptually equivalent translations and cultural adaptations should be performed in order to ensure comprehensibility. The final German version of LIMB-Q Kids is ready for use in an international field test.

Late Ankle Reconstruction in a Child with Remote Traumatic Medial Malleolus Loss: Clinical and Radiographic Outcomes.

Aim: This article aims to describe a novel surgical technique for medial malleolar reconstruction in a young child. Background: Severe open ankle injuries that result in bone and soft tissue loss carry a high risk for complications, especially in children who are still growing. These injuries can cause abnormal growth patterns, degenerative diseases, and recurrent instability. Cases of medial malleolar reconstruction have been previously described but none in a child this young. Case description: We present a case of an 13-year-old girl who suffered an open injury to the medial distal tibia with traumatic loss of the medial malleolus at the age of 2 and later suffered a Salter-Harris II fracture to the ipsilateral distal fibula. She presented with varus alignment, a leg length discrepancy, premature asymmetrical growth arrest, chronic non-union of the distal fibula physeal fracture, and severe attenuation of the deltoid ligament. Her secondary deformities were managed with distal fibula osteotomy and fixation, distal tibial hemi-plafond corrective osteotomy, and medial malleolus reconstruction with iliac crest autograft. Her leg length discrepancy was corrected by epiphysiodesis of the contralateral distal femur and proximal tibia. At the 2-year follow-up, the alignment was well maintained, the graft was healing well, and the patient reported no pain and being able to walk and play sports without a brace. Conclusion: Surgical reconstruction of the medial malleolus with correction for abnormal angulation and leg length discrepancies is critical to promoting healthy growth patterns and quality of life for paediatric patients. This severe open ankle injury can be successfully managed by distal fibula osteotomy and fixation, distal tibial intra-articular osteotomy, and medial malleolus reconstruction with iliac crest autograft. Clinical significance: This novel technique is an effective method for the surgical management of paediatric traumatic medial malleolar bone loss in children who are skeletally immature and are at risk of complications due to further growth. How to cite this article: Ponton E, Bakkai A, Courtemanche DJ, et al. Late Ankle Reconstruction in a Child with Remote Traumatic Medial Malleolus Loss: Clinical and Radiographic Outcomes. Strategies Trauma Limb Reconstr 2022;17(2):131-135.

Human complete NFAT1 deficiency causes a triad of joint contractures, osteochondromas, and B-cell malignancy.

The discovery of humans with monogenic disorders has a rich history of generating new insights into biology. Here we report the first human identified with complete deficiency of nuclear factor of activated T cells 1 (NFAT1). NFAT1, encoded by NFATC2, mediates calcium-calcineurin signals that drive cell activation, proliferation, and survival. The patient is homozygous for a damaging germline NFATC2 variant (c.2023_2026delTACC; p.Tyr675Thrfs∗18) and presented with joint contractures, osteochondromas, and recurrent B-cell lymphoma. Absence of NFAT1 protein in chondrocytes caused enrichment in prosurvival and inflammatory genes. Systematic single-cell-omic analyses in PBMCs revealed an environment that promotes lymphomagenesis with accumulation of naïve B cells (enriched for oncogenic signatures MYC and JAK1), exhausted CD4+ T cells, impaired T follicular helper cells, and aberrant CD8+ T cells. This work highlights the pleiotropic role of human NFAT1, will empower the diagnosis of additional patients with NFAT1 deficiency, and further defines the detrimental effects associated with long-term use of calcineurin inhibitors.

Efficacy and Safety of "Sleeper Plate" in Temporary Hemiepiphysiodesis and the Observation of "Tethering".

BACKGROUND: Guided growth is commonly performed by placing an extraperiosteal 2-hole plate across the growth plate with one epiphyseal and one metaphyseal screw. Recent studies investigated the efficacy of the removal of the metaphyseal screw only (sleeper plate) after correction. They concluded the practice to be unnecessary as only 19% of patients showed recurrence of deformity. This study aims to examine the incidence of rebound and undesired bony in-growth of the plate (tethering) after metaphyseal screw removal only. METHODS: In this retrospective case series, patient data on 144 plates inserted around the knee were obtained. Plates still in situ (n=69) at the time of study and full hardware removal (n=50) were excluded. The remaining 25 plates had only the metaphyseal screw removed after completed deformity correction. We analyzed the rate of tethering, rebound, and maintenance of correction in 2 age groups at latest follow (mean of 3.5 y). The Fisher exact test with Freeman-Halton extension was used to analyze categorical data and the Student t test for descriptive variables. RESULTS: Twenty-five plates were identified as "sleeper plates" in our series. Thirteen plates (52%) maintained the achieved correction after a mean of 21 months (range: 4 to 39 mo), 9 plates (36%) required screw reinsertion due to rebound after a mean of 22 months (range: 12 to 48 mo) from screw removal, and 4 plates (16%) showed tethering with undesired continuation of guided growth after a mean of 14 months (range: 7 to 22 mo) from screw removal. Younger patients (<8 y at time of plate insertion) had higher rates of rebound and tethering ( P =0.0112, Fisher exact test). All tethering occurred in titanium plates, none occurred in steel plates. CONCLUSIONS: The sleeper plate is an acceptable treatment strategy for coronal deformities around the knee, however, tethering and rebound may occur, especially in younger patients. Titanium plates may increase the risk of tethering, however, further long-term follow-up is needed as there were only 6 steel plates versus 19 titanium in this study. We stress the importance of close postoperative follow-up to identify signs of tethering and rebound early to prevent over-correction. LEVEL OF EVIDENCE: Level IV-retrospective case study.

Establishing content validity of LIMB-Q Kids: a new patient-reported outcome measure for lower limb deformities.

PURPOSE: To establish the content validity of LIMB-Q Kids, a new patient-reported outcome measure (PROM) for children with lower limb deformities. This study focused on three key components of content validity, i.e., comprehension, comprehensiveness, and relevance. METHODS: Cognitive debriefing interviews (CDIs) with children with lower limb deformities were performed, and expert input from parents and clinicians directly involved in the care of children with lower limb deformities was obtained. CDIs were conducted with children from sites in Australia, Canada, and the USA. All interviews were recorded and transcribed verbatim. Analyses were conducted using the reparative approach, which involved close examination of the transcribed interviews and summarising edits after each interview. RESULTS: Forty patients, experts, and parents reviewed LIMB-Q Kids and provided feedback. At the start, LIMB-Q Kids had 10 scales and 124 total items. Five rounds of input was obtained from children, parents, and experts. Overall, 37 new items were added. Thirty-three of the new items were included to measure symptoms experienced in different parts of the legs. Final version of LIMB-Q Kids had 11 scales and 159 items. CONCLUSION: This study established content validity of the LIMB-Q Kids, a new PROM for children with lower limb deformities. An international field-test study is underway. Translation and cultural adaptation are underway for sites where English is not the first language. Scoring algorithms will be developed, following which the scale could be used to inform clinical practice and research.