The Human Phenotype Ontology in 2024: phenotypes around the world.

The Human Phenotype Ontology (HPO) is a widely used resource that comprehensively organizes and defines the phenotypic features of human disease, enabling computational inference and supporting genomic and phenotypic analyses through semantic similarity and machine learning algorithms. The HPO has widespread applications in clinical diagnostics and translational research, including genomic diagnostics, gene-disease discovery, and cohort analytics. In recent years, groups around the world have developed translations of the HPO from English to other languages, and the HPO browser has been internationalized, allowing users to view HPO term labels and in many cases synonyms and definitions in ten languages in addition to English. Since our last report, a total of 2239 new HPO terms and 49235 new HPO annotations were developed, many in collaboration with external groups in the fields of psychiatry, arthrogryposis, immunology and cardiology. The Medical Action Ontology (MAxO) is a new effort to model treatments and other measures taken for clinical management. Finally, the HPO consortium is contributing to efforts to integrate the HPO and the GA4GH Phenopacket Schema into electronic health records (EHRs) with the goal of more standardized and computable integration of rare disease data in EHRs.

Collagen architecture and biomechanics of gracilis and adductor longus muscles from children with cerebral palsy.

Cerebral palsy (CP) describes some upper motoneuron disorders due to non-progressive disturbances occurring in the developing brain that cause progressive changes to muscle. While longer sarcomeres increase muscle stiffness in patients with CP compared to typically developing (TD) patients, changes in extracellular matrix (ECM) architecture can increase stiffness. Our goal was to investigate how changes in muscle and ECM architecture impact muscle stiffness, gait and joint function in CP. Gracilis and adductor longus biopsies were collected from children with CP undergoing tendon lengthening surgery for hamstring and hip adduction contractures, respectively. Gracilis biopsies were collected from TD patients undergoing anterior cruciate ligament reconstruction surgery with hamstring autograft. Muscle mechanical testing, two-photon imaging and hydroxyproline assay were performed on biopsies. Corresponding data were compared to radiographic hip displacement in CP adductors (CPA), gait kinematics in CP hamstrings (CPH), and joint range of motion in CPA and CPH. We found at matched sarcomere lengths muscle stiffness and collagen architecture were similar between TD and CP hamstrings. However, CPH stiffness (R2 = 0.1973), collagen content (R2 = 0.5099) and cross-linking (R2 = 0.3233) were correlated to decreased knee range of motion. Additionally, we observed collagen fibres within the muscle ECM increase alignment during muscular stretching. These data demonstrate that while ECM architecture is similar between TD and CP hamstrings, collagen fibres biomechanics are sensitive to muscle strain and may be altered at longer in vivo sarcomere lengths in CP muscle. Future studies could evaluate the impact of ECM architecture on TD and CP muscle stiffness across in vivo operating ranges. KEY POINTS: At matched sarcomere lengths, gracilis muscle mechanics and collagen architecture are similar in TD patients and patients with CP. In both TD and CP muscles, collagen fibres dynamically increase their alignment during muscle stretching. Aspects of muscle mechanics and collagen architecture are predictive of in vivo knee joint motion and radiographic hip displacement in patients with CP. Longer sarcomere lengths in CP muscle in vivo may alter collagen architecture and biomechanics to drive deficits in joint mobility and gait function.

Term-BLAST-like alignment tool for concept recognition in noisy clinical texts.

MOTIVATION: Methods for concept recognition (CR) in clinical texts have largely been tested on abstracts or articles from the medical literature. However, texts from electronic health records (EHRs) frequently contain spelling errors, abbreviations, and other nonstandard ways of representing clinical concepts. RESULTS: Here, we present a method inspired by the BLAST algorithm for biosequence alignment that screens texts for potential matches on the basis of matching k-mer counts and scores candidates based on conformance to typical patterns of spelling errors derived from 2.9 million clinical notes. Our method, the Term-BLAST-like alignment tool (TBLAT) leverages a gold standard corpus for typographical errors to implement a sequence alignment-inspired method for efficient entity linkage. We present a comprehensive experimental comparison of TBLAT with five widely used tools. Experimental results show an increase of 10% in recall on scientific publications and 20% increase in recall on EHR records (when compared against the next best method), hence supporting a significant enhancement of the entity linking task. The method can be used stand-alone or as a complement to existing approaches. AVAILABILITY AND IMPLEMENTATION: Fenominal is a Java library that implements TBLAT for named CR of Human Phenotype Ontology terms and is available at https://github.com/monarch-initiative/fenominal under the GNU General Public License v3.0.

Muscle satellite cells and fibro-adipogenic progenitors from muscle contractures of children with cerebral palsy have impaired regenerative capacity.

AIM: To evaluate the mechanosensitivity of muscle satellite cells (MuSCs) and fibro-adipogenic progenitors (FAPs) in cerebral palsy (CP) and the efficacy of the drug verteporfin in restoring cells' regenerative capacity. METHOD: Muscle biopsies were collected from six children with CP and six typically developing children. MuSCs and FAPs were isolated and plated on collagen-coated polyacrylamide gels at stiffnesses of 0.2 kPa, 8 kPa, and 25 kPa. Cells were treated with verteporfin to block mechanosensing or with dimethyl sulfoxide as a negative control. MuSC differentiation and FAP activation into myofibroblasts were measured using immunofluorescence staining. RESULTS: Surprisingly, MuSC differentiation was not affected by stiffness; however, stiff substrates resulted in large myonuclear clustering. Across all stiffnesses, MuSCs from children with CP had less differentiation than those of their typically developing counterparts. FAP activation into myofibroblasts was significantly higher in children with CP than their typically developing peers, but was not affected by stiffness. Verteporfin did not affect differentiation or activation in either cell population, but slightly decreased myonuclear clustering on stiff substrates. INTERPRETATION: Cells from children with CP were less regenerative and more fibrotic compared to those of their typically developing counterparts, with MuSCs being sensitive to increases in stiffness. Therefore, the mechanosensitivity of MuSCs and FAPs may represent a new target to improve differentiation and activation in CP muscle.

Posttraumatic Cubitus Varus: Respect the Columns.

Posttraumatic cubitus varus is a multiplanar deformity that results from an improperly reduced supracondylar humerus fracture. The prevention of posttraumatic cubitus varus hinges on the stable restoration of all 3 columns of the distal humerus while avoiding malrotation. The collapse of any column leads to varying degrees of deformity in the coronal, sagittal, and/or axial plane. The purpose of this article is to explain the pattern of the deformity and use this to summarize preventative tactics for avoiding its described sequelae. We also summarize, illustrate, and present case examples for the various osteotomies used to correct the deformity, and speculate future directions.

Reliability of a Photo-Based Modified Foot Posture Index (MFPI) in Quantifying Severity of Foot Deformity in Children With Cerebral Palsy.

INTRODUCTION: Children with cerebral palsy (CP) have high rates of foot deformity. Accurate assessment of foot morphology is crucial for therapeutic planning and outcome evaluation. This study aims to evaluate the reliability of a novel photo-based Modified Foot Posture Index (MFPI) in the evaluation of foot deformity in children with CP. METHODS: Thirteen orthopaedic surgeons with neuromuscular clinical focus from 12 institutions evaluated standardized standing foot photographs of 20 children with CP, scoring foot morphology using the MFPI. Raters scored the standardized photographs based on five standard parameters. Two parameters assessed the hindfoot: curvature above and below the malleoli and calcaneal inversion/eversion. Three parameters assessed the midfoot and forefoot: talonavicular congruence, medial arch height, and forefoot abduction/adduction. Summary MFPI scores range from -10 to +10, where positive numbers connote planovalgus, whereas negative numbers connote a tendency toward cavovarus. Intra- and interrater reliability were calculated using a 2-way mixed model of the intraclass correlation coefficient (ICC) set to absolute agreement. RESULTS: Feet spanned the spectrum of potential pathology assessable by the MFPI, including no deformity, mild, moderate, and severe planovalgus or cavovarus deformities. All scored variables showed high intrarater reliability with ICCs from 0.891 to 1. ICCs for interrater reliability ranged from 0.965 to 0.984. Hindfoot total score had an ICC of 0.979, with a 95% CI, 0.968-0.988 (P<0.001). The forefoot total score had an ICC of 0.984 (95% CI, 0.976-0.991, P<0.001). Mean total score by the MFPI was 3.67 with an ICC of 0.982 (95% CI, 0.972-0.990, P<0.001). CONCLUSIONS: The photo-based MFPI demonstrates high intra- and interrater reliability in assessing foot deformities in children with CP. Its noninvasive nature and ease of use make it a promising tool for both clinical and research settings. MFPI should be considered as part of standard outcomes scores in studies regarding the treatment of CP-associated foot deformities. LEVEL OF EVIDENCE: Level V.

HipScreen mobile app for the measurement of hip migration percentage in children with cerebral palsy: Accuracy, reliability, and discriminatory ability.

AIM: To assess the accuracy, reliability, and discriminatory ability of a mobile app for measurement of migration percentage in hip surveillance radiographs of children with cerebral palsy (CP). METHOD: The free mobile app HipScreen (www.hipscreen.org) was utilized by a diverse group of users to measure the migration percentage of 40 hips at two time points after completing an online tutorial and competency test. The mean absolute error (MAE) was calculated against the reference standard obtained on a radiology workstation. Statistical analyses included linear regression, intraclass correlation coefficient (ICC), and area under receiver-operating characteristic curve (AUC). RESULTS: Thirty-seven users completed the study, with 30 having a healthcare professional background, but only 15 with x-ray interpretation expertise. The overall MAE of migration percentage measurement using the HipScreen app was 5.72% (95% confidence interval [CI]: 5.38-6.06), with good reliability between time points (ICC = 0.83). With a migration percentage less than 30% considered as a positive case, the HipScreen app had a sensitivity of 94% (95% CI: 87-97), specificity of 66% (95% CI: 61-77), and an AUC of 0.92 (95% CI: 0.88-0.96). INTERPRETATION: Users from a broad range of backgrounds can utilize the HipScreen app to measure hip surveillance radiographs with clinically acceptable accuracy, reliability, and discriminatory ability. WHAT THIS PAPER ADDS: The HipScreen app can accurately and reliably measure migration percentage. As a screening tool, HipScreen has excellent sensitivity and discriminatory ability. A broad range of HipScreen users achieve clinically acceptable performance.

Surgical Management of Severe Equinus Deformity in Ambulatory Children With Cerebral Palsy.

BACKGROUND: Tendo Achilles lengthening (TAL) for the management of equinus contractures in ambulatory children with cerebral palsy (CP) is generally not recommended due to concerns of over-lengthening, resulting in weakness and plantar flexor insufficiency. However, in some cases, surgical correction of severe equinus deformities can only be achieved by TAL. The goal of this study is to assess the outcomes following TAL in these cases. METHODS: A retrospective cohort study of children with CP with severe equinus contractures (ankle dorsiflexion with the knee extended of -20 degrees or worse) who underwent TAL as part of a single event multilevel surgery, with preoperative and postoperative gait analysis studies. Continuous data were analyzed by paired t test, and categorical data by McNemar Test. RESULTS: There were 60 subjects: 42 unilateral, 18 bilateral CP; 41 GMFCS II, 17 GMFCS I; mean age at surgery was 10.6 years, mean follow-up was 1.3 years. Ankle dorsiflexion with the knee extended improved from -28 to 5 degrees (P<0.001). The ankle Gait Variable Score improved from 34.4 to 8.6 (P<0.001). The ankle moment in terminal stance improved from 0.43 to 0.97 Nm/kg (P<0.001). Significant improvements (P<0.001) were seen in radiographic measures of foot alignment following surgery. There were few significant differences in the outcome parameters between subjects with unilateral versus bilateral CP (eg, only the bilateral group showed improved but persistent increased knee flexion in mid-stance). CONCLUSIONS: The outcomes following TAL for the management of severe equinus deformity in ambulatory children with CP were favorable 1 year after surgery, with significant improvements in all domains measured. SIGNIFICANCE: This study does not advocate for the widespread use of TAL to correct equinus deformity in children with CP. However, it does show that good short-term outcomes following TAL are possible in properly selected subjects with severe contractures when the dosing of the surgery is optimal (correction of contracture to between 0 and 5 degrees of dorsiflexion with the knee extended) and the procedure is performed in the setting of single event multilevel surgery with subsequent proper orthotic management and rehabilitation.

Outcomes of Patellar Tendon Imbrication With Distal Femoral Extension Osteotomy for Treatment of Crouch Gait.

BACKGROUND: Crouch gait is a frequent gait abnormality observed in children with cerebral palsy. Distal femoral extension osteotomy (DFEO) with the tightening of the extensor mechanism is a common treatment strategy to address the pathologic knee flexion contracture and patella alta. The goal of this study was to review the results of a patellar tendon imbrication (PTI) strategy to address quadriceps insufficiency in the setting of children undergoing DFEO. METHODS: After institutional review board approval, all patients with crouch gait treated at a single institution with DFEO and PTI were identified. Clinical, radiographic, and instrumented gait analysis data were analyzed preoperatively and at 1 year following surgery. RESULTS: Twenty-eight patients (54 extremities) with a diagnosis of cerebral palsy and crouch gait were included. Significant improvements were appreciated in the degree of knee flexion contracture, quadriceps strength, knee extensor lag, and popliteal angle (P<0.01). Knee flexion at initial contact and during mid-stance improved significantly (P<0.0001), and knee moments in late stance were significantly reduced (P<0.01). The anterior pelvic tilt, however, significantly increased postoperatively (P<0.0001). Radiographic improvements were seen in the knee flexion angle and patellar station as assessed by the Koshino Sugimoto Index (P<0.0001). Four patients (14.2%) developed a recurrence of knee flexion contracture requiring further intervention. CONCLUSIONS: PTI is a simplified and safe technique to address quadriceps insufficiency when performing DFEO. The short-term results of patients who underwent DFEO with PTI demonstrated improvements in clinical, radiographic, and gait analysis variables of the knee. Investigating long-term outcomes, comparing techniques, and assessing quality of life measures are important next steps in research. LEVEL OF EVIDENCE: Level IV-case series.

Surgical Outcomes for Severe Idiopathic Toe Walkers.

BACKGROUND: Idiopathic toe walking (ITW) is a diagnosis of exclusion and represents a spectrum of severity. Treatment for ITW includes observation and a variety of conservative treatment methods, with surgical intervention often reserved for severe cases. Previous studies reviewing treatment outcomes are often difficult to interpret secondary to a mixture of case severity. The goal of this study was to review surgical outcomes in patients with severe ITW who had failed prior conservative treatment, as well as determine differences in outcomes based on the type of surgery performed. METHODS: After IRB approval, all patients with surgical management of severe ITW at a single institution were identified. Zone II or zone III plantar flexor lengthenings were performed in all subjects. Clinical, radiographic, and motion analysis data were collected preoperatively and at 1 year following surgery. RESULTS: Twenty-six patients (46 extremities) with a diagnosis of severe ITW from 2002 to 2017 were included. Zone II lengthenings were performed in 25 extremities (mean age=9.9 y) and zone III lengthenings were performed in 21 extremities (mean age=8.6 y). At the most recent follow-up, 100% of zone III lengthening extremities and 88% of zone II lengthening demonstrated decreased severity of ITW. Six extremities required additional treatment, all of which were initially managed with zone II lengthenings. CONCLUSIONS: Severe ITW or ITW that has not responded to conservative treatment may benefit from surgical intervention. More successful outcomes, including continued resolution of toe walking, were observed in subjects treated with zone III lengthenings. LEVEL OF EVIDENCE: Level III-case series.

Patella Alta in Ambulatory Children With Cerebral Palsy: Prevalence and Functional Significance.

BACKGROUND: Gait dysfunction associated with patella alta (PA) in subjects with cerebral palsy (CP) has been presumed but not objectively established clinically or through biomechanical modeling. It is hypothesized that PA is associated with increasing level of motor impairment, increasing age, obesity, and worse stance phase knee kinematics and kinetics in children with CP. METHODS: Retrospective case series of 297 subjects with CP studied in our Motion Analysis Center. Data analyzed included patient demographics (age, body mass index, CP classification), patella height (Koshino-Sugimoto Index), and knee kinematics and kinetics. RESULTS: PA was present in 180 of 297 subjects (61%), in 68 of the 146 (47%) with unilateral CP, and 112 of 151 subjects (74%) with bilateral CP. For unilateral CP, the prevalence of PA was not significantly different between Gross Motor Function Classification System (GMFCS) I and II (P=0.357). For bilateral CP, the prevalence of PA in GMFCS III was significantly greater than in GMFCS I and II (P=0.02). Regression analysis showed a significant trend between increasing age and PA in unilateral and bilateral groups (P<0.001 and 0.001, respectively). The prevalence of PA was not significantly different across body mass index categories for either unilateral or bilateral groups. There were only 2 of 10 significant correlations between PA and gait parameters for subjects with unilateral CP functioning at the GMFCS I and II levels. There were 8 of 12 significant correlations between PA and gait parameters for subjects with bilateral CP functioning at the GMFCS I, II, and III levels. CONCLUSIONS: PA is common in ambulatory children with CP across topographic types and motor functional levels. PA is well tolerated with respect to gait dysfunction in unilateral CP, but may contribute to crouch gait in bilateral CP. Gait dysfunction cannot be inferred from the radiographic assessment of patellar height, and radiographic evidence of PA by itself does not justify surgical correction with patellar tendon advancement or shortening. LEVEL OF EVIDENCE: Level III-prognostic, retrospective series.

Outcomes of Preoperative Versus Postoperative Radiation for Heterotopic Ossification Prevention in Children With Neuromuscular Hip Dysplasia Undergoing Proximal Femoral Resection.

BACKGROUND: Few studies exist to inform the extrapolated practice of irradiating children for heterotopic ossification (HO) prevention. We report the incidence of HO formation following prophylactic preoperative compared with postoperative radiation therapy (RT) in children with neuromuscular hip dysplasia (NHD) following proximal femoral resection (PFR). METHODS: A retrospective, 2-institution chart review was performed. Eligibility was limited to patients with at least 1 year of follow-up. Evaluation included radiographic HO grading by a combined severity scale, assessment of synchronous symptoms of pain or decreased range of motion, and stratification by preoperative versus postoperative reception of RT. A control cohort included 4 nonirradiated hips with NHD after PFR. RESULTS: Twenty-five hips in 20 children met eligibility criteria. Eleven hips were irradiated preoperatively and 14 postoperatively. Radiographic evidence of post-RT development of radiographic evidence of heterotopic ossification (rHO) was found in all 25 hips and earlier in patients irradiated preoperatively (median time to rHO was 4.0 vs. 15.7 mo, P=0.03, 95% confidence interval, 0.24-21.5). There was no statistically significant difference in the development of symptomatic HO (P=0.62) between the preoperative (45.5%) and postoperative (35.7%) groups, nor in HO grade (P=0.34). Seven (28%) of the 25 hips (5 preoperative and 2 postoperative) had documentation of rHO-free intervals after surgery, with an average duration of 5.6 months, while the remaining presented with rHO at first follow-up visit. All eligible control hips (100%) developed rHO and symptomatic heterotopic ossification. CONCLUSIONS: Perioperative RT did not prevent the formation of HO in any child with NHD after PFR. Extrapolation of evidence of the efficacy of RT for HO prevention in ambulatory adults after traumatic hip injury to a population of children with central nervous system injury and NHD may be premature. Additional studies are needed to clarify optimal prevention of HO in this population. LEVEL OF EVIDENCE: Level III-therapeutic retrospective comparative study.

Quantitative Assessment of Muscle Strength Following "Slow" Surgical Lengthening of the Medial Hamstring Muscles in Children With Cerebral Palsy.

BACKGROUND: Classic teaching for surgical lengthening of muscle contractures in children with cerebral palsy (CP) has emphasized complete correction of the deformity acutely, with immobilization of the targeted muscles in the fully corrected position. Clinical experience has led to the impression that the muscles are invariably weakened by this approach. We have developed an alternative technique for correction of contractures called slow surgical lengthening (SSL). The goal of the study was to determine the physical examination, kinematic, and muscle strength outcomes following SSL of the medial hamstring muscles in children with CP. METHODS: The study group included 41 children with CP who underwent SSL of the medial hamstring muscles as part of a comprehensive single-event multilevel surgery, who had preoperative and 1-year postoperative evaluations in our Motion Analysis Center, which included quantitative assessment of isometric and isokinetic muscle strength. RESULTS: All subjects were Gross Motor Function Classification System I and II. Mean age at the time of surgery was 10.8 years. The mean popliteal angle improved by 16.2 degrees (P<0.001) following SSL of the medial hamstrings. Sagittal plane kinematics following SSL of the medial hamstrings showed improvement of knee extension at initial contact of 10.2 degrees (P<0.001), decrease of peak knee flexion in mid-swing of 3.6 degrees (P=0.014), improved minimum knee flexion in stance of 4.9 degrees (P=0.002), and no significant change in mean anterior pelvic tilt (P=0.123). Mean peak isometric knee flexion torque remained unchanged from preoperative to postoperative studies (P=0.154), whereas mean peak isokinetic knee flexion torque significantly increased by 0.076 Nm/kg (P=0.014) following medial hamstring SSL. DISCUSSION: SSL was developed based upon clinical experience and improved understanding of the pathophysiology of skeletal muscle in children with CP. The SSL technique allows the tendinous tissue to separate spontaneously at the time of recession, but does not force further acute lengthening by intraoperative manipulation, thereby minimizing the damage to the underlying muscle. It is broadly believed that muscle weakness is inevitable following surgical lengthening. The current study shows that the SSL technique does not cause weakness. LEVEL OF EVIDENCE: Level IV-therapeutic.

Control of Walking Speed in Children With Cerebral Palsy.

BACKGROUND: Children's ability to control the speed of gait is important for a wide range of activities. It is thought that the ability to increase the speed of gait for children with cerebral palsy (CP) is common. This study considered 3 hypotheses: (1) most ambulatory children with CP can increase gait speed, (2) the characteristics of free (self-selected) and fast walking are related to motor impairment level, and (3) the strategies used to increase gait speed are distinct among these levels. METHODS: A retrospective review of time-distance parameters (TDPs) for 212 subjects with CP and 34 typically developing subjects walking at free and fast speeds was performed. Only children who could increase their gait speed above the minimal clinically important difference were defined as having a fast walk. Analysis of variance was used to compare TDPs of children with CP, among Gross Motor Function Classification System (GMFCS) levels, and children in typically developing group. RESULTS: Eight-five percent of the CP group (GMFCS I, II, III; 96%, 99%, and 34%, respectively) could increase gait speed on demand. At free speed, children at GMFCS I and II were significantly faster than children at GMFCS level III. At free speed, children at GMFCS I and II had significantly greater stride length than those at GMFCS levels III. At free speed, children at GMFCS level III had significantly lower cadence than those at GMFCS I and II. There were no significant differences in cadence among GMFCS levels at fast speeds. There were no significant differences among GMFCS levels for percent change in any TDP between free and fast walking. DISCUSSION: Almost all children with CP at GMFCS levels I and II can control the speed of gait, however, only one-third at GMFCS III level have this ability. This study suggests that children at GMFCS III level can be divided into 2 groups based on their ability to control gait speed; however, the prognostic significance of such categorization remains to be determined. LEVEL OF EVIDENCE: Diagnostic level II.

Guided Growth of the Proximal Femur for the Management of Hip Dysplasia in Children With Cerebral Palsy.

BACKGROUND: Progressive hip displacement is one of the most common and debilitating deformities seen in children with cerebral palsy (CP). The aim of this study was to evaluate the results of temporary medial hemiepiphysiodesis of the proximal femur (TMH-PF) using a transphyseal screw to control hip migration during growth in children with CP. METHODS: This was a retrospective study of children with CP and hip dysplasia, age 4 to 11 years and GMFCS levels III-V. There were 28 patients with 56 hips that underwent TMH-PF surgery between 2007 and 2010. Clinical and radiologic evaluation was performed preoperatively, at 6, 12, and 60 months following the index surgery. Acetabular index (AI), neck-shaft angle (NSA) and migration percentage (MP) were measured. All complications were recorded. RESULTS: All radiographic measurements were significantly improved at the final follow-up. Positive correlations were found between NSA, MP, and AI. Multiple regression analysis revealed that MP, time from surgery, and age were influenced by the decrease of the NSA. The femoral physis grew off the screw in 9 hips within 36 months. The screw head broke during attempted screw exchange in 1 hip. The remain cases (4 hips) were treated by placing a second screw parallel to the existing one. Finally, progressive subluxation occurred in 3 hips when the physis grew off the screw and were treated by skeletal reconstruction. CONCLUSIONS: TMH-PF was effective in controlling progressive subluxation of the hip in the majority of cases, obviating the need for major reconstructive surgery in these children with CP. LEVEL OF EVIDENCE: Level IV.

Management of Neuromuscular Hip Dysplasia in Children With Cerebral Palsy: Lessons and Challenges.

Optimal clinical decision making and surgical management of hip dysplasia in children with cerebral palsy (CP) requires an understanding of the underlying pathophysiology (pathomechanics and pathoanatomy), incidence, and natural history. The incidence of hip dysplasia in children with CP is directly related to the degree of motor impairment. A subluxated or dislocated hip in a child with CP can compromise the quality of life for both the child and their caregivers. The goal of this article is to highlight the events over the last 25 years that have had the greatest impact on the management of hip dysplasia in children with CP. It is my opinion that the 2 most significant advances during this time have been the development of a classification system based upon motor impairment (the Gross Motor Function Classification System), and the development of surveillance programs for hip dysplasia in children with CP. This article will contrast neuromuscular hip dysplasia with developmental dysplasia of the hip. It will be shown how the development and utilization of the Gross Motor Function Classification System has contributed to our understanding of the epidemiology and natural history of hip dysplasia in children with CP, and to the assessment of outcomes following surgical management. The impact of hip surveillance programs on early soft tissue surgeries, skeletal hip reconstructions, and the incidence of hip dislocations and salvage surgeries will be reviewed. Challenges in the implementation of hip surveillance programs in resource poor and decentralized health care delivery systems will be considered, and innovative approaches identified.

Quantitative Assessment of Knee Progression Angle During Gait in Children With Cerebral Palsy.

BACKGROUND: Abnormal hip rotation is a common deviation in children with cerebral palsy (CP). Clinicians typically assess hip rotation during gait by observing the direction that the patella points relative to the path of walking, which is referred to as the knee progression angle (KPA). Two kinematic methods for calculating the KPA are compared with each other. Video-based qualitative assessment of KPA is compared with the quantitative methods to determine reliability and validity. METHODS: The KPA was calculated by both direct and indirect methods for 32 typically developing (TD) children and a convenience cohort of 43 children with hemiplegic type CP. An additional convenience cohort of 26 children with hemiplegic type CP was selected for qualitative assessment of KPA, performed by 3 experienced clinicians, using 3 categories (internal, >10 degrees; neutral, -10 to 10 degrees; and external, >-10 degrees). RESULTS: Root mean square (RMS) analysis comparing the direct and indirect KPAs was 1.14+0.43 degrees for TD children, and 1.75+1.54 degrees for the affected side of children with CP. The difference in RMS among the 2 groups was statistically, but not clinically, significant (P=0.019). Intraclass correlation coefficient revealed excellent agreement between the direct and indirect methods of KPA for TD and CP children (0.996 and 0.992, respectively; P<0.001).For the qualitative assessment of KPA there was complete agreement among all examiners for 17 of 26 cases (65%). Direct KPA matched for 49 of 78 observations (63%) and indirect KPA matched for 52 of 78 observations (67%). CONCLUSIONS: The RMS analysis of direct and indirect methods for KPA was statistically but not clinically significant, which supports the use of either method based upon availability. Video-based qualitative assessment of KPA showed moderate reliability and validity. The differences between observed and calculated KPA indicate the need for caution when relying on visual assessments for clinical interpretation, and demonstrate the value of adding KPA calculation to standard kinematic analysis. LEVEL OF EVIDENCE: Level II-diagnostic test.

Correlation Between Standard Upper Extremity Impairment Measures and Activity-based Function Testing in Upper Extremity Cerebral Palsy.

BACKGROUND: Although the treatment of cerebral palsy should be based on improving function as assessed by measures of impairment, activity, and participation, the standard indications for surgical treatment of upper extremity cerebral palsy (UECP) are impairment measures, primarily active and passive range of motion (ROM). Recently, validated activity measures have been developed for children with UECP. The purposes of this study were to determine the relationship between impairment and activity measures in this population, and whether measures of activity correlate with each other. METHODS: A total of 37 children, ages 5 to 16 years, who met standard ROM surgical indications for UECP were evaluated with the impairment measures of active and passive ROM and stereognosis, as well as 3 activity measures [Assisting Hand Assessment (AHA), Box and Blocks test, and the Shriners Hospitals Upper Extremity Evaluation Dynamic Positional Analyses (SHUEE DPA)]. Impairment measures were correlated with activity measures using Spearman rank correlation coefficients. RESULTS: Impairment measures showed inconsistent correlation with activity measures. Of the 12 comparisons, only 4 correlated: active forearm supination (ρ=0.47, P=0.003), wrist extension (ρ=0.55, P=0.001), and stereognosis scores (ρ=0.54, P=0.001) were correlated with AHA; and wrist extension was correlated with the SHUEE DPA (ρ=0.41, P=0.01). When the results of activity tests were compared, the AHA was correlated with the Box and Blocks tests (ρ=0.63, P<0.001), and the SHUEE DPA and Box and Blocks tests were correlated with each other (ρ=0.35, P=0.04). CONCLUSIONS: The goal of surgery in UECP is to improve the child's ability to perform activities, and ultimately to participate in life situations. Impairment measures, such as ROM, were inconsistently correlated with validated measures of activity. Some activity measures correlated with each other, although they did not correlate with the same impairment measures. We conclude that impairment measures, including ROM, do not consistently predict functional dynamic ROM used to perform activities for children with UECP. Activity limitation measures may provide more appropriate indicators than impairment measures for upper extremity surgery for this population. LEVEL OF EVIDENCE: Level II-diagnostic.

Selective Control of the Upper Extremity Scale: validation of a clinical assessment tool for children with hemiplegic cerebral palsy.

AIM: The ability to determine the relationship between selective motor control and upper extremity function in children with unilateral cerebral palsy (CP), and to measure the functional outcome and efficacy of interventions designed to improve selective motor control, has been limited by the lack of an objective, validated tool. The primary objective of this study is to describe the development of a clinical tool entitled Selective Control of the Upper Extremity Scale (SCUES), and present evidence of its validity and reliability. METHOD: Content validity was established through an expert panel (eight clinicians, mean and median of 17y of clinical experience, range 2-30y). Intra- and interrater reliability was determined by six occupational therapists who scored 10 participant studies. Construct validity of the SCUES was established by comparison to the spontaneous functional analysis section of the Shriners Hospitals Upper Extremity Evaluation, the Manual Ability Classification System, and the Box and Block test for 25 children with unilateral CP. RESULTS: The content validity ratio values were greater than 0 (indicating >50% agreement) for 33 of the 34 items (97%), and equal or greater than 0.5 (indicating ≥75% agreement) for 26 of the 34 items (76%). Intrarater reliability was excellent (intraclass correlation coefficient [ICC] >0.75) for all segments and joints of the affected extremity. Interrater reliability was excellent for all segments and joints of the affected extremity except the shoulder (ICC=0.72). The SCUES was strongly correlated with the SHUEE (Spearman's rho=0.69, p=0.003). The SCUES was not correlated with the Manual Ability Classification System (rho=-0.24, p=0.369) or the Box and Block test (rho=0.47, p=0.066). INTERPRETATION: Psychometric analysis of the SCUES revealed comparable validity to other accepted video-based clinical assessment tools for the upper extremity in children with CP.

Correction of Tibial Torsion in Children With Cerebral Palsy by Isolated Distal Tibia Rotation Osteotomy: A Short-term, In Vivo Anatomic Study.

BACKGROUND: Excessive internal or external tibial torsion is frequently present in children with cerebral palsy. Several surgical techniques have been described to correct excessive tibial torsion, including isolated distal tibial rotation osteotomy (TRO). The anatomic changes surrounding this technique are poorly understood. The goal of the study was to examine the anatomic relationship between the tibia and fibula following isolated distal TRO in children with cerebral palsy. METHODS: Twenty patients with 29 limbs were prospectively entered for study. CT scans of the proximal and distal tibiofibular (TF) articulations were obtained preoperatively, at 6 weeks, and 1 year postoperatively. Measurements of tibia and fibula torsion were performed at each interval. Qualitative assessments of proximal and distal TF joint congruency were also performed. RESULTS: The subjects with internal tibia torsion (ITT, 19 limbs) showed significant torsional changes for the tibia between preoperative, postoperative, and 1 year time points (mean torsion 13.21, 31.05, 34.84 degrees, respectively). Measurement of fibular torsion in the ITT treatment group also showed significant differences between time points (mean -36.77, -26.77, -18.54 degrees, respectively). Proximal and distal TF joints remained congruent at all time points in the study.Subjects with external tibia torsion (ETT, 10 limbs) showed significant differences between preoperative and postoperative tibial torsion, but not between postoperative and 1 year (mean torsion 54, 19.3, 23.3 degrees, respectively). Measurement of fibular torsion in the ETT treatment group did not change significantly between preoperative and postoperative, but did change significantly between postoperative and 1 year (mean torsion -9.8,-16.9, -30.7 degrees, respectively). Nine of 10 proximal TF joints were found to be subluxated at 6 weeks postoperatively. At 1 year, all 9 of these joints had reduced. CONCLUSIONS: Correction of ITT by isolated distal tibial external rotation osteotomy resulted in acute external fibular torsion. The fibular torsion alignment remodeled over time to accommodate the corrected tibial torsional alignment and reduce the strain associated with the plastic deformity of the fibula. Correction of ETT by isolated distal internal TRO resulted in acute subluxation of the proximal TF articulation in almost all cases. Subsequent torsional remodeling of the fibula resulted in correction of the TF subluxation in all cases. Acute correction of TT by isolated distal TRO occurs by distinct mechanisms, based upon the direction of rotational correction. LEVEL OF EVIDENCE: Level II-Diagnostic.