Effect of Static Alignment on Dynamic Knee Abduction Moments in Adolescent Athletes with Recent ACL Reconstruction.

PURPOSE: Dynamic limb valgus, particularly high knee abduction moments, is a known risk factor for anterior cruciate ligament (ACL) injury and may result from poor static anatomic limb alignment, faulty biomechanics, or a combination of both. The purpose of this study was to assess the influence of static lower extremity anatomic alignment and dynamic kinematic/kinetic measures on knee abduction moments during sidestep cutting in adolescent athletes with recent ACL reconstruction. METHODS: This retrospective study included 50 adolescents with recent unilateral ACL reconstruction (18/50 female, mean age = 15.8 yr, 7.6 months postsurgery). Frontal plane hip-to-ankle imaging was used to measure mechanical axis deviation and tibial-femoral angle. Three-dimensional motion capture provided lower extremity kinematics and kinetics during quiet standing and during the loading phase (initial contact to peak knee flexion) of an anticipated 45° sidestep cut. Imaging, static motion capture, and dynamic motion capture measures were investigated as potential predictors of average dynamic knee abduction moment using correlation and backward stepwise linear regression. RESULTS: Dynamic knee abduction moment was best predicted by a combination of younger age and dynamic measures: trunk lean toward the planting limb, knee abduction and external rotation, and ankle inversion. Although static measures were correlated with dynamic knee abduction moment in univariate analysis, no static/anatomic variables entered the model once the dynamic measures were included. CONCLUSION: Knee abduction moments during sidestep cutting were related to dynamic factors reflecting frontal and transverse plane motion. Static (anatomic) lower limb alignment did not influence knee abduction moments once these dynamic factors were considered. Knee abduction moments and ACL injury risk are therefore not dictated by anatomic alignment and can be altered through neuromuscular/biomechanical training.

Relationships among classifications of impairment and measures of ambulatory function for children with spina bifida.

PURPOSE: To examine associations between neurosegmental and functional level classifications in children with Spina Bifida, and determine which classification best reflects daily walking activity. MATERIALS AND METHODS: A prospective correlational study was conducted. Children with Spina Bifida were given ratings for lesion level [X-ray and International Myelodysplasia Study Group (IMSG) level determined by muscle strength] and functional level [Hoffer ambulatory level and Dias functional classification of myelomeningocele (FCM), Functional Mobility Scale (FMS)]. Daily walking activity was measured with a StepWatch monitor. Data were analyzed using Spearman rank correlation. RESULTS: Sixty-one children were included, [56% male, average age 9.8 (SD 2.7) years]. The neurosegmental level classifications, X-ray lesion level and IMSG level showed little to no correlation with each other (r = 0.17). Among functional classifications, the Dias FCM correlated strongly with the FMS (r = 0.80-0.87). Correlations with steps per day were moderate to good for the Dias FCM and the FMS (r = 0.53-0.62), fair for IMSG level (r = 0.45), and little to none for X-ray lesion level (r = 0.03). CONCLUSIONS: The Dias FCM is comprehensive, including elements of neurosegmental level and function, and correlates well with walking activity. We recommend its use for classifying function in patients with Spina Bifida.Implications for rehabilitationFunctional classifications correlate better with daily walking activity than neurosegmental level classifications for patients with Spina Bifida.The Dias FCM includes neurosegmental and functional level elements, correlates well with daily activity, and is recommended for use in classifying Spina Bifida patients.Combined use of the FMS and activity monitoring is recommended for research and clinical assessment.

Quantitative Computed Tomography Assessment of Bone Deficits in Ambulatory Children and Adolescents with Spina Bifida: Importance of Puberty.

Pathologic fractures of the femur and tibia are common in youth with spina bifida (SB). These fractures may be associated with deficient bone accrual due to decreased ambulation and skeletal loading. This prospective cohort study used quantitative computed tomography (QCT) to assess three-dimensional (3D) bone properties in children and adolescents with SB. Eighty-three ambulatory youth with SB underwent QCT imaging of the tibia at up to four annual visits between ages 6 to 16 years (294 total visits averaging 3.5 visits/patient). A total of 177 controls without disability and 10 non-ambulatory youth with SB underwent imaging once. Bone geometric properties (cortical bone area, cross-sectional area, cortical thickness, cortical density, and moments of inertia) were measured at the mid-diaphysis (50% of bone length); cross-sectional area, cancellous density, and density-weighted area were measured in the proximal (13% of bone length) and distal (90% of bone length) metaphyses. Bone properties were compared between the ambulatory SB and control participants, among SB neurosegmental subgroups (sacral, low lumbar, mid lumbar and above) as a function of pubertal stage (prepubertal, pubertal, postpubertal), and considering SB type (myelomeningocele, lipomyelomeningocele) using linear mixed effects models adjusted for sex, age, height percentile, and body mass index (BMI) percentile. Only cancellous density of both metaphyses and weighted area of the proximal metaphysis differed between ambulatory children with SB and controls before puberty. However, significant deficits in all bone properties manifested during and after puberty as moderate bone growth in the SB group failed to keep pace with the large increases normally observed during puberty. The bone deficits primarily affected patients with myelomeningocele, and similar deficits were observed at all neurosegmental levels except that cancellous density was closer to normal in the sacral group. Descriptive analysis of the 10 non-ambulatory youth with SB showed greater bone deficits than ambulatory children, particularly for cancellous density in the distal metaphysis. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Hip Dysplasia Is Not More Common in W-Sitters.

Parents are frequently cautioned by therapists, teachers, physicians, and online resources about potential negative effects of w-sitting in children (including hip dysplasia), despite lack of evidence. To examine relationships between w-sitting and hip dysplasia, a prospective cohort study was conducted of 104 patients (196 hips), aged 9.9 (standard deviation = 5.7) years, who underwent hip/pelvis radiography at a pediatric tertiary care center. Measures of hip dysplasia were taken from radiographs. Parents/patients completed a questionnaire regarding the patients' sitting habits. Associations between hip dysplasia and w-sitting were analyzed statistically. About 48/104 parents/patients (46%) reported current or past w-sitting: 11/104 (11%) current, preferred position; 23/104 (22%) current, nonpreferred position, 14/104 (13%) w-sat in past, and 56/104 (54%) never w-sat. There was no difference in measures of hip dysplasia (P > .12) or hip dysplasia frequency between w-sitters (9%) and non-w-sitters (10%; P = .81), or among w-sitting persistence groups (P = .26). W-sitting in children is not associated with hip dysplasia.

Movement variability in pre-teen and teenage athletes performing sports related tasks.

BACKGROUND: Understanding movement variability is important to guide biomechanical assessment. Variability may change with age, and more repetitions of a movement need to be assessed when variability is high. RESEARCH QUESTION: This study quantified the trial-to-trial (within subject) variability of three tasks commonly assessed during sports biomechanical testing: vertical drop jump, heel touch (single leg squat from step), and single leg hop. We hypothesized that pre-teen athletes would exhibit greater variability than more mature teenage athletes when performing all of these movements. METHODS: Fifty-five uninjured pediatric athletes ages 7-15 years performed 3 repetitions of vertical drop jump, heel touch, and single leg hop for distance tasks during 3D motion analysis testing. Trial-to-trial variability was assessed using the standard deviation (SD) and range (maximum-minimum) of clinically relevant kinematic and kinetic metrics among the multiple repetitions of each task performed by each participant. Variability was compared between age groups using 2-sided t-tests. Standard error of measurement (SEM) and minimum detectable difference (MDD) were also calculated for each variable of interest. RESULTS: For drop jump and heel touch, kinetic variability was similar between groups, but the younger group had greater kinematic variability. However, the older group was much more variable than the younger group during single leg hop landing, particularly in terms of kinetics and sagittal plane kinematics. Overall, kinematic variability had a median within-subject SD of 1-9°, median range of 2-17°, and 95th percentile for range of >15-20° for many of the variables examined. MDD was >10° for many kinematic variables, >0.2 Nm/kg for all frontal plane moments, >0.4 Nm/kg for most sagittal plane moments, and >0.5 W/kg for most energy absorption variables. SIGNIFICANCE: The high within-subject trial-to-trial variability in performing sports tasks suggests that multiple trials should be analyzed for a more complete and representative evaluation.

Improvements in landing biomechanics following anterior cruciate ligament reconstruction in adolescent athletes.

Motion analysis offers objective insight into biomechanics, rehabilitation progress and return to sport readiness. This study examined changes in three-dimensional movement patterns during drop jump landing between early and late stages of rehabilitation in adolescent athletes following anterior cruciate ligament reconstruction (ACLR). Twenty-four athletes (58% female; mean age 15.4 years, SD 1.2) with unilateral ACLR underwent motion analysis testing 3-6 months and again 6-10 months post-operatively. Kinematics and kinetics were compared between visits and between limbs using repeated measures ANOVA. The operative side exhibited lower vertical ground reaction force, less energy absorption and lower sagittal external moments at the knee and ankle, and lower peak dorsiflexion angles compared with the non-operative side regardless of visit. Between visits, hip and knee flexion increased bilaterally, as well as hip flexion moments and energy absorption. During early rehabilitation following ACLR, adolescent athletes reduced flexion and loading of the knee and ankle on their operative limb. Motion and loading increased over time, particularly at the hip, but remained reduced at the knee and ankle 6-10 months post-operatively.

Rectus Femoris Transfer Surgery Worsens Crouch Gait in Children With Cerebral Palsy at GMFCS Levels III and IV.

BACKGROUND: Previous study has shown that children with cerebral palsy (CP) functioning at Gross Motor Function Classification System (GMFCS) levels III and IV do not benefit from distal rectus femoris transfer (DRFT) due to lack of improvement in stance knee extension. The fate of knees in such subjects who do not undergo DRFT is unknown. The purpose of this study was to compare knee kinematic outcomes in patients with CP and stiff knee gait who underwent single-event multilevel surgery with and without DRFT. METHODS: Preoperative and postoperative gait analysis data were retrospectively reviewed for ambulatory (GMFCS levels I to IV) patients with CP with crouch and stiff knee gait whom underwent single-event multilevel surgery, including hamstring lengthening either with DRFT (N=34) or without DRFT (N=40). Statistical analyses included t tests and χ tests, and multiple regression analysis was performed to adjust for covariates. Data were stratified by GMFCS level groups I/II and III/IV. RESULTS: Improved maximum knee extension in stance was seen for both the DRFT (P=0.0002) and no DRFT groups (P≤0.0006) at GMFCS levels I/II, and the no DRFT group at GMFCS levels III/IV (P=0.02). Excessive stance knee flexion persisted for those at GMFCS level III/IV after DRFT. Maximum knee flexion in swing was maintained after DRFT, but significantly decreased in the no DRFT group (P<0.002) for both GMFCS groups. Change in total knee range of motion improved after DRFT only in the GMFCS I/II group subjects with unilateral involvement (P=0.01). Timing of maximum knee flexion in swing improved for all patients regardless of DRFT or GMFCS level group (P<0.0001). CONCLUSIONS: In patients with CP functioning at GMFCS levels III and IV, DRFT results in persistent crouch postoperatively. Given the importance of maintaining upright posture in these patients, we do not recommend DRFT in patients functioning at GMFCS levels III and IV. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Percutaneous Hamstring Lengthening Surgery is as Effective as Open Lengthening in Children With Cerebral Palsy.

BACKGROUND: Surgical lengthening of the hamstrings is often performed to correct crouch gait in children with cerebral palsy (CP). Previous studies have demonstrated the effectiveness of open hamstring lengthening (oHSL) in improving knee extension static and dynamic range of motion; however, literature regarding percutaneous hamstring lengthening (pHSL) is limited. The purpose of this study was to investigate the effect of open versus pHSL for improving crouch gait and knee function in children with CP. METHODS: This retrospective cohort study included 87 ambulatory children with CP who underwent HLS surgery with both preoperative and postoperative gait analysis (mean time, 29.4±19.9 mo after surgery) testing between 1997 and 2015. In total, 65 patients underwent oHLS surgery (mean age, 8.5±2.5 y) and 22 patients underwent pHSL surgery (mean age, 8.3±2.3 y). Lower extremity three-dimensional kinematic data were collected while subjects walked at a self-selected speed. Outcome variables for operative limbs were compared within and between groups using t tests, χ tests, and multiple regression analysis. RESULTS: Significant postoperative decreases in knee flexion at initial contact were seen for both open (Δ12.7±13.4 degrees; P<0.001) and percutaneous (Δ19.1±13.1 degrees; P<0.001) groups. Increased postoperative maximum knee extension in stance was found for both open (Δ8.2±16.8 degrees; P=0.001) and percutaneous (Δ14.4±16.5 degrees; P=0.001) groups. No significant differences between open and percutaneous groups were found when comparing postoperative changes in kinematic variables between groups after adjusting for covariates. Postoperative changes in static range of motion were similar between lengthening groups. CONCLUSIONS: pHSL is as effective as open lengthening in improving stance phase knee kinematics during gait in children with CP. This is the first study to compare the kinematic effects of open versus pHSL in the pediatric population. Percutaneous lengthening is tolerated well by patients, and as it allows for rapid rehabilitation it may be preferable to the open procedure. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Myosteatosis in adolescents and young adults treated for acute lymphoblastic leukemia.

Myosteatosis refers to fat deposition within muscle and is linked to risk of cardiovascular disease and metabolic disorders. Though these comorbidities are common during and after therapy for acute lymphoblastic leukemia (ALL), little is known about tissue distribution, including myosteatosis, in this population. Using quantitative computed tomography, we assessed the impact of ALL therapy on bone, muscle, subcutaneous, and muscle-associated (MA) fat in 12 adolescents and young adults (AYA) treated for ALL as compared to a healthy control group without ALL (n = 116). AYA had a marked loss of muscle with a gain in MA fat between ALL diagnosis and end of induction. These changes persisted throughout intensive therapy. Lower bone and muscle and higher MA fat were also observed during and after treatment in comparison to controls. Altered lower extremity tissue distribution, specifically myosteatosis and sarcopenia, may contribute to functional declines and increased risk of metabolic disorders and cardiovascular diseases.

Impact of gait analysis on pathology identification and surgical recommendations in children with spina bifida.

BACKGROUND: Gait analysis provides quantitative data that can be used to supplement standard clinical evaluation in identifying and understanding gait problems. It has been established that gait analysis changes treatment decision making for children with cerebral palsy, but this has not yet been studied in other diagnoses such as spina bifida. RESEARCH QUESTION: To determine the effects of gait analysis data on pathology identification and surgical recommendations in children with spina bifida. METHODS: Two pediatric orthopaedic surgeons and two therapists with >10 years of experience in gait analysis reviewed clinical, video, and gait analysis data from 43 ambulatory children with spina bifida (25 male; mean age 11.7 years, SD 3.8; 25 sacral, 18 lumbar). Primary gait pathologies were identified by each assessor both before and after consideration of the gait analysis data. Surgical recommendations were also recorded by the surgeons before and after consideration of the gait analysis data. Frequencies of pathology and surgery identification with and without gait analysis were compared using Fisher's exact test, and percent change in pathology and surgery identification was calculated. RESULTS: Pathology identification often changed for common gait problems including crouch (28% of cases), tibial rotation (35%), pes valgus (18%), excessive hip flexion (70%), and abnormal femur rotation (75%). Recognition of excessive hip flexion and abnormal femur rotation increased significantly after consideration of gait analysis data (p < 0.05). Surgical recommendations also frequently changed for the most common surgeries including tibial derotation osteotomy (30%), antero-lateral release (22%), plantar fascia release (33%), knee capsulotomy (25%), 1st metatarsal osteotomy (60%), and femoral derotation osteotomy (89%). At the patient level, consideration of gait analysis data altered surgical recommendations for 44% of patients. SIGNIFICANCE: Since gait analysis data often changes pathology identification and surgical recommendations, treatment decision making may be improved by including gait analysis in the patient care process.

Pre-operative hamstring length and velocity do not explain the reduced effectiveness of repeat hamstring lengthening in children with cerebral palsy and crouch gait.

BACKGROUND: Hamstring lengthening surgery (HSL) is often performed to correct crouch gait in patients with cerebral palsy (CP). However, crouch can recur over time, and repeat HSL may be ineffective. One possible reason is that the hamstrings in repeat HSL patients are neither short nor lengthening slowly and would therefore not benefit from HSL. RESEARCH QUESTION: This study aimed to determine whether the hamstrings are short and/or slow preoperatively only in patients with primary, and not repeat, HSL. METHODS: We compared pre- and postoperative dynamic semimembranosus muscle-tendon lengths for children with CP who had primary (N = 15) or repeat (N = 8) HSL to a group of control participants (N = 10). Outcome measures were compared between visits (pre- vs. postoperative) and groups (control, primary HSL, repeat HSL) using mixed model analysis. RESULTS: Preoperatively, hamstrings were shorter and slower than normal on average in both HSL groups (p < 0.001); all but 3 limbs (primary 26/28, repeat 13/14) had hamstrings that were shorter and/or slower than controls by more than two standard deviations. Postoperative improvements were observed in the primary HSL group for popliteal angle, initial contact knee flexion, minimum stance knee flexion, and dynamic hamstring length (p ≤ 0.001). The repeat HSL group improved only in dynamic hamstring length (p = 0.004) and worsened in passive knee extension (p = 0.01) and minimum hip flexion in stance (p = 0.04). Hamstrings in both surgical groups on average remained shorter and slower than controls postoperatively (p ≤ 0.001). SIGNIFICANCE: The fact that repeat HSL is less effective in improving knee motion is not due to a lack of short or slow hamstrings preoperatively. However, in recurrent crouch, short or slow hamstrings do not usually indicate hamstring dysfunction, and correction of other deformities such as rotational malalignment, fixed knee flexion contractures, patella alta, weak calf muscles, and/or loose heelcords should be considered rather than repeat HSL.

Comparison of drop jump landing biomechanics and asymmetry among adolescents with hamstring, patellar and quadriceps tendon autografts for anterior cruciate ligament reconstruction.

BACKGROUND: Adolescent anterior cruciate ligament reconstruction (ACLR) commonly utilizes hamstring (HT), patellar (PT) or quadriceps (QT) tendon autografts, but consensus is lacking regarding optimal graft choice. This study compared landing biomechanics and asymmetries among ACLR patients with HT, PT and QT grafts and uninjured controls. METHODS: This retrospective study included 61 adolescents with unilateral ACLR (27 HT, 20 PT, 14 QT; four to 12 months post-surgery, mean 6.4; age 15.4, SD 1.4 years) and 27 controls (14.6, SD 0.9 years) who were evaluated during drop jump landings. Lower extremity 3D biomechanics and asymmetries were compared. RESULTS: Compared to controls, all operative limbs exhibited 1) greater hip flexion and lower dorsiflexion angles; 2) higher hip and lower knee and ankle flexion moments; 3) higher energy absorption at the hip (HT and QT only) and lower at the knee and ankle; and 4) higher knee abduction moments. Asymmetries observed in all ACLR groups included 1) lower knee and ankle flexion angles; 2) lower knee and ankle flexion moments; 3) lower energy absorption at the knee and ankle; and 4) higher hip and knee abduction moments on the operative side. The PT and QT groups demonstrated greater asymmetry in hip and knee flexion moments compared to HT. CONCLUSIONS: While adolescent ACLR limbs offloaded the knee and ankle, patients with PT or QT grafts demonstrated greater deficiencies during rehabilitation than those reconstructed with HT. Graft choice in ACLR should remain patient-specific and aim to optimize biomechanics with the ultimate goal of minimizing graft re-tear and donor site morbidity.

Children with myelomeningocele do not exhibit normal remodeling of tibia roundness with physical development.

Skeletal loading through daily movement is an important factor in the normal development of bones. This loading is affected by the neurological and muscle deficits that result from myelominingocele (MM). While children with MM have been shown to have atypical gait, decreased bone accrual, and increased fracture risk, it is still unclear what morphological bone differences exist and to what extent they relate to physical developmental and ambulation level. This study analyzed computed tomography images of the tibia from 77 children with MM and 124 typically developing (TD) children between the ages of 6 and 16 years. Differences in cross-sectional roundness along the length of the tibia diaphysis were observed across developmental stages (pre-pubertal, pubertal, post-pubertal) and ambulation level (MM non-ambulatory, MM assistive devices, MM independent, and TD). The results showed that tibia cross-sectional morphology becomes less round with development in TD children (p < 0.017). In children with MM, however, roundness is maintained throughout adolescence (p > 0.017), with greater roundness in less ambulatory children (p < 0.0083). These in vivo results align with mechanobiological modeling studies suggesting that intracortical loads (caused by joint loading) as well as periosteal loads (imposed by surrounding muscles) are critical in promoting non-circular cross-sectional bone shape remodeling.

Motion analysis evaluation of adolescent athletes during dual-task walking following a concussion: A multicenter study.

BACKGROUND: Research suggests that dynamic balance in adolescents is compromised following concussion and may worsen if patients return to sport (RTS) too soon. Understanding if there are ongoing dynamic balance deficits in adolescents at the time of RTS clearance would determine if more complex motor tasks are necessary to facilitate safe RTS decisions. RESEARCH QUESTION: The purpose of this study was to determine if there were remaining dynamic balance deficits in concussed adolescents at the time of clearance for RTS. METHODS: Sixteen concussed adolescent athletes (age 14.6 ±â€¯1.8 years; 9 males; 57 ±â€¯46 days post injury) performed a simple walking task as well as two split attention gait tasks (reciting months backwards and audio Stroop). The center of mass (COM) movement and walking velocity during these tasks was compared to a control group of 15 healthy non-concussed adolescent athletes (age 13.8 ±â€¯1.4 years; 9 male). RESULTS: The results indicated that there were no statistically significant differences between the two groups for any of the tasks. Height-normalized walking speed did not differ between groups during walking alone (control: 0.757 ±â€¯0.119, concussed: 0.739 ±â€¯0.108, p = 0.34), with the recitation task (control: 0.555 ±â€¯0.095, concussed: 0.557 ±â€¯0.143, p = 0.72), or with the Stroop task (control: 0.589 ±â€¯0.129, concussed: 0.567 ±â€¯0.141, p = 0.43). Similarly, height-normalized medial-lateral COM displacement did not differ between groups during walking alone (control: 0.027 ±â€¯0.007, concussed: 0.028 ±â€¯0.007, p = 0.98, with the recitation task (control: 0.037 ±â€¯0.012, concussed: 0.0.037 ±â€¯0.016, p = 0.82), or with the Stroop task (control: 0.032 ±â€¯0.014, concussed: 0.033 ±â€¯0.009, p = 0.891). SIGNIFICANCE: These findings indicate that the patients were returned to sport when their dynamic balance was similar to controls suggesting that this cohort had recovered from their concussion. However, large variability in dynamic balance measures in both the patient and control groups may reflect ongoing neuromuscular development and requires further exploration.

Hop Distance Symmetry Does Not Indicate Normal Landing Biomechanics in Adolescent Athletes With Recent Anterior Cruciate Ligament Reconstruction.

Background Return-to-sport protocols after anterior cruciate ligament reconstruction (ACLR) often include assessment of hop distance symmetry. However, it is unclear whether movement deficits are present, regardless of hop symmetry. Objectives To assess biomechanics and symmetry of adolescent athletes following ACLR during a single-leg hop for distance. Methods Forty-six patients with ACLR (5-12 months post surgery; 27 female; mean ± SD age, 15.6 ± 1.7 years) were classified as asymmetric (operative-limb hop distance less than 90% that of nonoperative limb [n = 17]) or symmetric (n = 29) in this retrospective cohort. Lower extremity biomechanics were compared among operative and contralateral limbs and 24 symmetric controls (12 female; mean ± SD age, 14.7 ± 1.5 years) using analysis of variance. Results Compared to controls, asymmetric patients hopped a shorter distance on their operative limb (P<.001), while symmetric patients hopped an intermediate distance on both sides (P≥.12). During landing, the operative limb, regardless of hop distance, exhibited lower knee flexion moments compared to controls and the contralateral side (P≤.04), with lower knee energy absorption than the contralateral side (P≤.006). During takeoff, both symmetric and asymmetric patients had less hip extension and smaller ankle range of motion on the operative side compared with controls (P≤.05). Asymmetric patients also had lower hip range of motion on the operative, compared with the contralateral, side (P = .001). Conclusion Both symmetric and asymmetric patients offloaded the operative knee; symmetric patients achieved symmetry, in part, by hopping a shorter distance on the contralateral side. Therefore, hop distance symmetry may not be an adequate test of single-limb function and return-to-sport readiness. J Orthop Sports Phys Ther 2018;48(8):622-629. Epub 30 Mar 2018. doi:10.2519/jospt.2018.7817.

Limitations of body mass index to assess body composition due to sarcopenic obesity during leukemia therapy.

Obesity as defined by body mass index percentile (BMI%) is strongly associated with relapse and poorer survival in childhood ALL. Whether BMI% accurately reflects body fat percentage (BF%) in this population is unknown. We conducted a prospective study assessing body composition during frontline ALL therapy. Dual-energy X-ray absorptiometry measured BF% and lean muscle mass (LMM) at diagnosis, end of Induction, and end of Delayed Intensification. Sarcopenic obesity (gain in BF% with loss of LMM) was surprisingly common during ALL treatment, resulting in poor correlation between changes in BMI% (expressed as Z-score) and BF% overall (r = -0.05) and within patients (r = -0.09). BMI Z-score and BF% changed in opposite directions in >50% of interval assessments. While BMI% at diagnosis is a suitable predictor of obesity/BF% for epidemiological studies, change in BMI% (as expressed as Z-score) does not reflect body composition. Studies evaluating obesity in leukemia should consider using direct measures of body composition.

Advanced skeletal maturity in children and adolescents with myelomeningocele.

PURPOSE: Atypical skeletal development is common in youth with myelomeningocele (MM), though the underlying reasons have not been fully elucidated. This study assessed skeletal maturity in children and adolescents with MM and examined the effects of sex, age, sexual development, ethnicity, anthropometrics and shunt status. METHODS: Forty-three males and 35 females with MM, 6-16 years old, underwent hand radiographs for bone age determination. The difference between bone age and chronological age was evaluated using Wilcoxon sign rank tests. Relationships between age discrepancy (skeletal-chronological) and participant characteristics were assessed using multiple linear regression with forward selection. RESULTS: Overall, forty percent (31/78) of MM participants had an advanced bone age of 1 year or greater (median: 2.5 years), while 47% (37/78) were within 1 year above or below their chronological age (-0.001 years) and 13% (10/78) were delayed by more than 1 year (-1.4 years). Bone age was advanced compared to chronologic age in both males and females (p⩽ 0.024). Advanced bone age was observed in early to late puberty and after maturation (p⩽ 0.07), as well as in Hispanic participants (p= 0.003) and in those with a shunt (p= 0.0004). Advanced bone age was positively correlated with height, weight and body mass index (BMI) percentiles (p= 0.004). In multiple linear regression analysis, advanced bone age was most strongly associated with higher Tanner stage of sexual development, and higher weight, height or BMI percentile. CONCLUSIONS: Advanced skeletal maturity is common in children/adolescents with MM over 8 years of age who have reached puberty (65%), particularly those who are overweight (80%). Hormonal effects associated with adiposity and sexual maturity likely influence skeletal maturation. Clinicians may use Tanner stage and weight or BMI to gain insight into skeletal maturity.

A comparison of three methods of measuring tibial torsion in children with myelomeningocele and normally developing children.

Abnormal tibial torsion is a common pediatric problem, and there are many existing measurement methods. The purpose of this study was to compare three methods of measuring tibial torsion for its evaluation: computed tomography, physical examination, and motion capture. Twenty healthy children and 20 children with myelomeningocele underwent measures of tibial torsion bilaterally. Measurements were compared using correlation and Bland-Altman plots of the difference between measurements. All three measurements were moderately correlated in controls (r ≥ 0.49, P ≤ 0.002) and in patients (r ≥ 0.51, P ≤ 0.001). In controls, the motion capture measurements were on average 2° more lateral than the clinical measurements whereas motion capture and clinical measurements were 13° and 15° more medial than CT measurements, respectively. Similarly for patients, motion capture measurements were on average 5° more medial than clinical measurements, and motion capture and clinical measurements were 26° and 22° more medial than CT measurements. The approximate 20° difference between the clinical or motion capture measures and the CT measure suggests that clinical evaluation identifies different axes than those defined based on skeletal anatomy. Clinical or motion capture methods may be used in lieu of imaging methods for measuring tibial torsion with the knowledge that these methods provide less lateral measurements than measurements obtained using CT. Clin. Anat. :1043-1048, 2017. © 2017 Wiley Periodicals, Inc.

A randomized controlled trial testing an adherence-optimized Vitamin D regimen to mitigate bone change in adolescents being treated for acute lymphoblastic leukemia.

Adolescents with acute lymphoblastic leukemia (ALL) develop osteopenia early in therapy, potentially exacerbated by high rates of concurrent Vitamin D deficiency. We conducted a randomized clinical trial testing a Vitamin D-based intervention to improve Vitamin D status and reduce bone density decline. Poor adherence to home supplementation necessitated a change to directly observed therapy (DOT) with intermittent, high-dose Vitamin D3 randomized versus standard of care (SOC). Compared to SOC, DOT Vitamin D3 successfully increased trough Vitamin 25(OH)D levels (p = .026) with no residual Vitamin D deficiency, 100% adherence to DOT Vitamin D3, and without associated toxicity. However, neither Vitamin D status nor supplementation impacted bone density. Thus, this adherence-optimized intervention is feasible and effective to correct Vitamin D deficiency in adolescents during ALL therapy. Repletion of Vitamin D and calcium alone did not mitigate osteopenia, however, and new, comprehensive approaches are needed to address treatment-associated osteopenia during ALL therapy.

Walking activity during daily living in children with myelomeningocele.

PURPOSE: To quantify the walking activity of children with myelomeningocele during daily living. METHOD: Walking activity was measured using a StepWatch activity monitor over one week in 47 children with myelomeningocele (27 males; 9 years 11 months SD 2 years 7 months; 18 sacral, 9 low lumbar, 20 mid-high lumbar) and seven children with typical development (5 males; 11 years 1 month SD 1 year 11 months) in a prospective, cross-sectional study. Average total steps per day, number of steps and minutes spent at low, medium and high intensity stepping were evaluated. Groups were compared using t-tests and chi-squared tests with Bonferroni post-hoc adjustment. RESULTS: Children with sacral and low lumbar myelomeningocele exhibited no significant differences in demographic characteristics or walking performance compared to typically developing children. Children with mid-high lumbar myelomeningocele exhibited higher BMI percentile than the control group (p = 0.04) and took fewer total steps per day than all other groups (p ≤ 0.04). Children with mid-high lumbar myelomeningocele also spent significantly less time taking steps at all intensity levels, particularly medium-intensity, than the sacral and low lumbar groups (p ≤ 0.04). CONCLUSIONS: Children with sacral and low lumbar myelomeningocele had walking performance similar to typically developing children despite a common need for braces and assistive devices. Children with mid-high lumbar myelomeningocele were less active, which may lead to heightened risk for secondary health conditions in addition to those associated with myelomeningocele. Implications for Rehabilitation Obesity, muscle weakening and disuse osteoporosis are issues for those with myelomeningocele, all of which are affected by walking activity. Understanding walking activity and intensity in children and adolescents with myelomeningocele may aid in developing focused rehabilitation interventions and strategies. Real world walking activity as an objective and quantified measure has the potential to help guide therapists and surgeons to more effective treatments.