Long-term effects of spasticity treatment, including selective dorsal rhizotomy, for individuals with cerebral palsy.

AIM: To understand the long-term effects of comprehensive spasticity treatment, including selective dorsal rhizotomy (SDR), on individuals with spastic cerebral palsy. METHOD: This was a pre-registered, multicenter, retrospectively matched cohort study. Children were matched on age range and spasticity at baseline. Children at one center underwent spasticity treatment including SDR (Yes-SDR, n=35) and antispastic injections. Children at two other centers had no SDR (No-SDR, n=40 total) and limited antispastic injections. All underwent subsequent orthopedic treatment. Participants returned for comprehensive long-term assessment (age ≥21y, follow-up ≥10y). Assessment included spasticity, contracture, bony alignment, strength, gait, walking energy, function, pain, stiffness, participation, and quality of life. RESULTS: Spasticity was effectively reduced at long-term assessment in the Yes-SDR group and was unchanged in the No-SDR group. There were no meaningful differences between the groups in any measure except the Gait Deviation Index (Yes-SDR + 11 vs No-SDR + 5) and walking speed (Yes-SDR unchanged, No-SDR declined 25%). The Yes-SDR group underwent more subsequent orthopedic surgery (11.9 vs 9.7 per individual) and antispastic injections to the lower limbs (14.4 vs <3, by design). INTERPRETATION: Untreated spasticity does not cause meaningful impairments in young adulthood at the level of pathophysiology, function, or quality of life.

Comparing short-term outcomes between conus medullaris and cauda equina surgical techniques of selective dorsal rhizotomy.

AIM: To compare short-term outcomes between conus medullaris (conus) and cauda equina (cauda) selective dorsal rhizotomy (SDR) techniques in children with spastic cerebral palsy. METHOD: This was a retrospective review of SDR at a single center from 2013 to 2017. Gait and functional outcome measures were assessed at no more than 18 months pre-SDR (baseline) and 8 to 36 months post-SDR (follow-up). Transient complications during inpatient stay were quantified. RESULTS: In total, 21 and 59 children underwent conus and cauda SDR respectively. Ashworth Scale scores were nearly normalized at follow-up. Most physical examination and functional measures exhibited similar baseline to follow-up responses for both groups. From baseline to follow-up, sagittal plane knee kinematics for both groups significantly improved (p<0.01) by 11° at initial contact, 9° to 10° in stance phase, and 4° in swing phase. Sagittal plane ankle kinematics improved more for the cauda group than the conus group in both stance phase (10° vs 2°, p<0.01) and swing phase (13° vs 3°, p<0.01). Post-surgical complications were similar between groups. INTERPRETATION: Conus and cauda SDR techniques resulted in similar short-term outcomes except in ankle kinematics at follow-up. The cauda group exhibited a large improvement towards dorsiflexion, while there was residual equinus in the conus group despite Ashworth Scale scores normalizing equally in both groups. WHAT THIS PAPER ADDS: Conus and cauda selective dorsal rhizotomy (SDR) resulted in mostly similar short-term gait and functional outcomes. Conus SDR resulted in residual equinus dynamically, despite normalized spasticity measures. Post-surgical complications were mostly similar between SDR techniques.

Knee pain and crouch gait in individuals with cerebral palsy: what impact does crouch-related surgery have?

AIM: To investigate the effect of crouch-related surgery on knee pain in individuals with cerebral palsy. METHOD: We retrospectively identified individuals with two three-dimensional gait analyses at baseline and follow-up visits. All individuals walked in crouch gait at baseline. Visits were 9 months to 42 months apart. Baseline knee pain, age, crouch-related surgery (yes/no), and minimum knee flexion at follow-up were entered into a logistic regression to predict follow-up knee pain. RESULTS: Thirty-two individuals (21 males, 11 females; mean [SD] age 12y 10mo [2y 5mo]; 8y 1mo-18y 7mo) received crouch-related surgery, while 19 were managed non-surgically. At baseline, knee pain prevalence was 38% in the surgical group and 21% in the non-surgical group. At follow-up, 34% of the surgical group and 16% of the non-surgical group had knee pain (odds ratio: 2.809, p=0.285). INTERPRETATION: Crouch-related surgery does not appear to decrease knee pain prevalence compared to a comparison group, based on this preliminary study. Further investigation of the roles of these procedures is indicated with regards to this patient-reported outcome. What this paper adds Approximately 38% of individuals undergoing crouch-related surgery had knee pain. Approximately 42% of individuals with baseline knee pain who had surgery still had knee pain 1 year postoperatively. Approximately 50% of those with baseline knee pain managed non-surgically still had knee pain 1 year later. Crouch-related surgery tended not to decrease knee pain prevalence 1 year postoperatively.

Dolor de rodilla y marcha en cuclillas en personas con parálisis cerebral: ¿qué impacto tiene la cirugía indicadas para esta deformidad? OBJETIVO: Investigar el efecto de la cirugía relacionada con la marcha en cuclillas con el dolor de rodilla en personas con parálisis cerebral. MÉTODO: Identificamos retrospectivamente a los individuos con dos análisis tridimensionales de la marcha al inicio y en las visitas de seguimiento. Todos los individuos caminaron en cuclillas al inicio del estudio. Las visitas fueron de 9 a 42 meses de diferencia. El dolor al inicio, edad, la cirugía relacionada con este tipo de marcha (sí / no) y la flexión mínima de la rodilla en el seguimiento, se ingresaron en una regresión logística para predecir el dolor de rodilla de seguimiento. RESULTADOS: Treinta y dos individuos (21 varones, 11 mujeres; media [DE] edad 12 años 10 meses [2 años 5 meses]; 8 años 1 mes - 18 años 7 meses) recibieron cirugía para corregir esta alteración, mientras que 19 fueron manejados sin cirugía. Al inicio del estudio, la prevalencia del dolor de rodilla fue del 38% en el grupo quirúrgico y del 21 por ciento en el grupo no quirúrgico. En el seguimiento, el 34% del grupo quirúrgico y el 16% del grupo no quirúrgico tenían dolor de rodilla (odds ratio: 2,809, p = 0,285). INTERPRETACIÓN: Según este estudio preliminar, la cirugía relacionada para la marcha en cuclillas, no parece disminuir la prevalencia del dolor de rodilla en comparación con un grupo de comparación. Se sugiere una investigación adicional de las funciones de estos procedimientos con respecto a los resultados informados por pacientes.

Dor no joelho e marcha agachada em indivíduos com paralisia cerebral: qual o impacto da cirurgia relacionada à marcha agachada? OBJETIVO: Investigar o efeito de cirurgia relacionada à marcha agachada na dor no joelho de indivíduos com paralisia cerebral. MÉTODO: Identificamos retrospectivamente indivíduos com duas análises tridimensionais da marcha em visitas de linha de base e acompanhamento. Todos os indivíduos apresentavam marcha agachada na linha de base. As visitas tiveram de 9 a 42 meses de distância. A dor no joelho, idade, cirurgia relacionada à marcha agachada (sim/não) na linha de base, e flexão mínima do joelho no acompanhamento foram inseridas em uma regressão logístia para predizer a dor no joelho no acompanhamento. RESULTADOS: Trinta e dois indivíduos (21 do sexo masculino, 11 do sexo feminino; média [DP] de idade 12a 10m [2a 5m]; 8a 1m-18a 7m) receberam cirurgia relacionada à marcha agachada, enquanto 19 tiveram manejo não-cirúrgico. Na linha de base, a prevalência de dor no joelho era 38 por cento no grupo cirúrgico, e 21 por cento no grupo não-cirúrgico. No acompanhamento, 34 por cento do grupo cirúrgico e 16 por cento do grupo não cirúrgico tiveram dor no joelho (taxa de risco: 2,809, p=0,285). INTERPRETAÇÃO: A cirurgia relacionada à marcha agachada não parece diminuir a prevalência de dor no joelho em relação a um grupo de comparação, com base neste estudo preliminar. Mais investigações sobre o papel destes procedimentos são indicadas, com relação a este desfecho relatado pelos pacientes.

Association of Knee Pain and Crouch Gait in Individuals With Cerebral Palsy.

BACKGROUND: Crouch gait (ie, excessive knee flexion) is commonly seen in patients with cerebral palsy (CP) and has been inconsistently linked with knee pain. The definitive cause of knee pain is unknown, but may result from increased joint forces due to crouch gait kinematics. Our purpose was to determine whether knee pain is positively associated with knee flexion in gait among a large sample of ambulatory individuals with CP. We hypothesized that knee pain prevalence would increase as knee flexion increased. METHODS: In this retrospective study, pain questionnaire and 3-dimensional gait analysis data from 2015 to 2018 were extracted from the medical records of individuals with CP who had a clinical gait analysis. The pain questionnaire asked caregivers/patients to indicate the location of pain and when it occurs. A multivariate logistic regression was performed with minimum knee flexion in stance, patella alta, age, and sex as predictors of knee pain. RESULTS: Among the 729 participants included in the analysis, 147 reported knee pain (20.1%). The odds of knee pain were not associated with minimum knee flexion in stance or sex. However, the odds of knee pain increased 73.2% when patella alta was present (P=0.008) and tended to increase 2.2% as age increased (P=0.059). CONCLUSIONS: The data suggest that there is not a meaningful association between crouch gait and knee pain. Having patella alta was associated with pain. Further studies that use validated pain questionnaires are needed to understand the multifactorial etiology of knee pain within ambulatory individuals with CP. LEVEL OF EVIDENCE: Level III-case-control study.

What's New in the Orthopaedic Treatment of Ambulatory Children With Cerebral Palsy Using Gait Analysis.

BACKGROUND: Limb deformities in ambulatory children with cerebral palsy (CP) are common. The natural history of lower extremity deformities is variable and the impact on gait is managed with many treatment modalities. Effective interventions must consider the underlying pathophysiology, patient-specific goals, and incorporate objective outcome assessment. Evaluation and treatment include observation, tone management multilevel orthopaedic surgery to address muscle contractures and bony deformities, and the use of gait analysis for preoperative and postoperative assessment. METHODS: A PubMed search of the orthopaedic literature for studies published between January 2016 and February 2019 was performed. Eligible abstracts included the use of 3-dimensional instrumented gait analysis in the evaluation and treatment of the lower extremities in ambulatory children with CP. Seven hundred twenty abstracts were reviewed, with 84 papers identified as eligible, of which 45 full manuscripts were included for detailed review. RESULTS: The review summarized recent advances regarding the treatment of torsional alignment, knee deformities and clinical gait evaluation with visual assessment tools compared with instrumented gait analysis. CONCLUSIONS: Gait analysis of ambulatory children with CP remains essential to evaluation and surgical decision-making. Promising results have been reported with the goal of maintaining or reaching a higher level of function and increased endurance. LEVEL OF EVIDENCE: Level IV-literature review.

Interobserver reliability in the interpretation of three-dimensional gait analysis in children with gait disorders.

AIM: To assess interobserver reliability in the interpretation of three-dimensional gait analysis (3DGA) of children with gait disorders within a single institution. METHOD: Seven experienced interpreters in our institution participated in a quality-assurance program reviewing one unique patient's 3DGA data every 3 months. Between 2014 and 2017, 15 patients' data were interpreted (14 with spastic cerebral palsy, 1 with myelodysplasia). Interpreters were asked to select 'yes', 'no', or 'indeterminate' from a list of problems and treatment recommendations. Kappa and percent agreement calculations were performed to evaluate consistency. RESULTS: Average percentage agreement in problem identification and treatment recommendation was greater than 84 percent and 90 percent for all interpreters respectively. Average kappa for the 10 most consistently identified problems and recommended treatments were 0.69 and 0.59 respectively. Interpreter consistency was moderate or better for the most commonly performed operations at our institution (0.44-0.59). Sagittal plane abnormalities of the hip and knee had the highest consistency. INTERPRETATION: When institutional differences in data collection and regional variations in management philosophies are removed, interobserver consistency in 3DGA interpretation is moderate to substantial for many commonly selected items. Identification of areas with poor consistency may help address underlying causes and improve data processes. WHAT THIS PAPER ADDS: Consistency in three-dimensional gait analysis interpretation and treatment recommendation is high within a single institution. There is moderate or better consistency for most commonly identified problems and recommended treatments. Sagittal plane problem identification of the hip and knee have the highest consistency. Lower consistency is seen in areas with poor objective measures, such as dystonia and balance.

FIABILIDAD INTEREVALUADOR EN LA INTERPRETACIÓN DEL ANÁLISIS TRIDIMENSIONAL DE LA MARCHA EN NIÑOS CON TRASTORNOS DE LA MARCHA: OBJETIVO: Evaluar la fiabilidad interevaluador en la interpretación del análisis tridimensional de la marcha de niños con trastornos de la marcha, pertenecientes a una institución. MÉTODO: Siete evaluadores de la institución con experiencia participaron en un programa de aseguramiento de calidad, revisando los datos del análisis tridimensional de la marcha de un único paciente cada 3 meses. Entre 2014 y 2017, se interpretaron los datos de 15 pacientes (14 con parálisis cerebral espástica, 1 con mielodisplasia). Se solicitó a los intérpretes seleccionar "sí", "no", o "indeterminado" frente a una lista de problemas y recomendaciones de tratamiento. Se calculó el coeficiente de Kappa y el porcentaje de acuerdo, para evaluar la consistencia. RESULTADOS: El porcentaje de acuerdo promedio en la identificación de problemas y recomendaciones de tratamiento fue mayor que 8% y 90% para todos los intérpretes, respectivamente. El coeficiente de Kappa promedio para los 10 problemas y recomendaciones de tratamiento más identificados fue 0,69 y 0,59, respectivamente. La consistencia de intérpretes fue moderada o mejor para las operaciones más frecuentemente realizadas en nuestra institución (0,44-0,59). Los defectos en el plano sagital de la cadera y rodilla tuvieron la mayor consistencia. INTERPRETACIÓN: Cuando se elimina las diferencias en la recolección de datos y en las variaciones regionales de filosofías de manejo, la consistencia interobservador en la interpretación del análisis tridimensional de la marcha es moderada a buena, para las categorías seleccionadas más frecuentes. La identificación de áreas con baja consistencia podría ayudar a abordar causas subyacentes y mejorar el procesamiento de los datos.

CONFIABILIDADE INTER-EXAMINADORES NA INTERPRETAÇÃO DE ANÁLISE TRIDIMENSIONAL DA MARCHA EM CRIANÇAS COM DESORDENS DA MARCHA: OBJETIVO: Avaliar a confiabilidade inter-examinadores na interpretação de análise tridimensional da marcha (A3DM) em crianças com desordens de marcha de um único instituto. MÉTODO: Sete intérpretes experientes de nossa instituição participaram de um programa de avaliação de qualidade revisando os dados de A3DM de um único paciente a cada 3 meses. Entre 2014 e 2017, os dados de 15 pacientes foram intepretados (14 com paralisia cerebral espástica, 1 com mielodisplasia). Os intérpretes foram solicitados a selecionar "sim", "não", ou "indeterminado" a partir de uma lista de problemas e recomendações de tratamento. Cálculos de concordância kappa e porcentagens foram realizados para avaliar a consistência. RESULTADOS: A porcentagem média de concordância na identificação de um problema e recomendação de tratamento foi maior do que 84% e 90% para todos os intérpretes, respectivamente. O kappa médio para os 10 problemas mais consistentemente identificados e tratamentos mais recomendados foi 0,69 e 0,59, respectivamente. A consistência dos intérpretes foi moderada ou melhor para as operações mais comumente realizadas em nossa instituição (0,44-0,59). Anormalidades no plano sagital do quadril e joelho tiveram a maior consistência. INTERPRETAÇÃO: Quando diferenças institucionais na coleta de dados, e variações regionais em filosofias de manejo são removidas, a consistência inter-examinadores da interpretação da A3DM é de moderada a substancial para muitos dos itens comumente selecionados. A identificação de áreas com pobre consistência pode ajudar a abordar causas e melhorar processos de dados.

Anterior Guided Growth of the Distal Femur for Knee Flexion Contracture: Clinical, Radiographic, and Motion Analysis Results.

BACKGROUND: Fixed knee flexion deformity is common in children with neuromuscular disorders. Anterior guided growth (AGG) of the distal femur can achieve gradual correction in patients who are skeletally immature. Little outcome data are available on this procedure. METHODS: This is a retrospective matched cohort study. Forty-two knees (26 patients) underwent AGG surgery at our institution between 2007 and 2017. All patients underwent instrumented 3-dimensional gait analysis (3DGA). A nonsurgical control group of 49 knees (43 patients) was selected that matched for age, severity of preoperative knee contracture, and 3DGA parameters. Clinical, radiographic, and 3DGA outcomes were assessed and compared. RESULTS: Average preoperative knee flexion deformity in AGG group was 13±8 degrees. Following AGG, deformity improved by 8±7 degrees (P<0.001) as measured radiographically and by 7±7 degrees (P<0.001) as measured on physical examination. Average rate of correction was 0.7±0.6 degrees per month or 8±8 degrees per year. The 3DGA parameters such as minimum stance phase knee flexion and knee flexion at initial contact were also significantly improved following AGG. In contrast, flexion deformity as measured radiographically worsened by 3±3 degrees (P=0.002) in the control group. Twelve knees (29%) had failure of correction. Predictors of failure included older age, lower level of function, and greater severity of preoperative deformity. The age at time of surgery and the anteroposterior position of plate fixation relative to the distal femoral physis were associated with rate of correction. CONCLUSIONS: In children with neuromuscular disorders, AGG of the distal femur is effective in improving degree of fixed knee flexion deformity as well as objective gait parameters. A significant portion of knees experience inadequate correction. Addressing factors associated with correction failure (ie, age and plate placement) may improve the procedure's success. LEVEL OF EVIDENCE: Level III-case control study.

Should Proximal Femoral Implants be Removed Prophylactically or Reactively in Children With Cerebral Palsy?

BACKGROUND: Implants are commonly used to stabilize proximal femoral osteotomies in children with cerebral palsy (CP). Removal of implants is common practice and believed to avoid infection, fracture, or pain that might be associated with retained hardware. There is little evidence to support a prophylactic strategy over a reactive approach based on symptoms. The aim of this study was to compare the outcomes of prophylactic and reactive approaches to removal of proximal femoral implants in children with CP. METHODS: An intention-to-treat model was used to compare 2 institutions that followed a prophylactic (within ∼1 y) and reactive (following complication/symptoms) approach to hardware removal, respectively. Patients with CP who had femoral implants placed at or before age 16, and had ≥2-year postsurgical follow-up were included. Demographics, surgical details, reasons for removal, and complications were recorded. χ and t tests were used. RESULTS: Six hundred twenty-one patients (prophylactic=302, reactive=319) were followed for an average of 6 years (range, 2 to 17 y). Two hundred eighty-seven (95%) implants were removed in the prophylactic group at 1.2 years. In the reactive group, 64 (20%) implants were removed at an average of 4.2 years. Reasons for removal included pain; infection; fracture; or for repeat reconstruction. The rate of unplanned removals due to fracture or infection was higher in the reactive group (4.7% vs. 0.7%, P=0.002), but there was no difference in the rate of complications during/after removal between the 2 groups (1.7% vs. 3.1%; P=0.616). No specific risk factor associated with unplanned removal could be identified; but children under 8 years old seemed more likely to undergo later removal (odds ratio 1.98; 95% confidence interval, 0.99-3.99). CONCLUSIONS: Eighty percent of patients in the reactive removal strategy avoided surgery. This group did have a 4% higher rate of fracture or infection necessitating unplanned removal but these were successfully treated at time of removal with no difference in complication rates associated with removal between both groups. One would need to remove implants from 25 patients to avoid 1 additional complication, providing some support for a reactive approach to removal of proximal femoral implants in this population. LEVEL OF EVIDENCE: Level III-therapeutic.

Proximal versus distal femoral derotation osteotomy in bilateral cerebral palsy.

AIM: Femoral derotation osteotomy (FDO) can be conducted either proximally or distally to correct internal rotation gait (IRG) and increased anteversion in children with cerebral palsy (CP). Previous studies with limited numbers of participants have presented comparable short-term static and kinematic outcomes for both techniques. The objective of this retrospective multicentre study was to verify this thesis with a larger number of patients. METHOD: In total, 119 children with CP and IRG were included after matching the groups on preoperative mean stance hip rotation: 67 intertrochanteric (proximal group) FDO (average age at surgery 9y [SD 3y]); 52 supracondylar (distal group) FDO (average age at surgery 12y [SD 3y]). One random limb of each child was analyzed. Both transverse plane kinematic gait data and torsional parameters of clinical examination were assessed preoperatively and postoperatively. RESULTS: On average, both groups' mean hip rotation and midpoint of hip rotation improved postoperatively, and groups did not differ preoperatively or postoperatively for these variables (p>0.05). INTERPRETATION: The osteotomy location does not influence short-term gait kinematics nor static measurements. Therefore, the choice of performing proximal or distal FDO in children with CP for treatment of IRG and increased anteversion should be motivated by considerations other than these outcome parameters. WHAT THIS PAPER ADDS: Femoral derotation osteotomy (FDO) location does not influence mean stance hip rotation in cerebral palsy (CP). FDO location does not influence mid-point hip rotation in CP. FDO location should be motivated by concomitant procedures performed.

Changes in hip abductor moment 3 or more years after femoral derotation osteotomy among individuals with cerebral palsy.

AIM: To examine the effect of femoral derotation osteotomy (FDO) on dimensionless hip abductor moment during gait in children with cerebral palsy. METHODS: We retrospectively analyzed data from independent ambulators within our database. Postoperative visits 1 year (short-term) and at least 3 years (mid-term) were analyzed. We estimated the coronal plane hip abductor moment arm based on musculoskeletal modeling that accounted for anteversion and hip rotation. RESULTS: There were 140 individuals with a short-term analysis (77 males, 63 females; age at surgery 9y 11mo [range 4y 5mo-17y 5mo]) and 29 with mid-term analysis (15 males, 14 females; age at surgery 8y 7mo [range 4y 5mo-13y 1mo]). At short-term, anteversion and internal hip rotation decreased 35° and 13° respectively, which increased median (IQR) moment arms from 20 (23) per cent below normal to 2 (12) per cent above normal. Dimensionless mean hip abductor moment remained unchanged at short-term. Mid-term anteversion did not change but hip rotation increased 8° and hip abductor moment increased to 0.040 (0.029). There was no change in pelvic and trunk obliquity, although hip abductor strength increased and walking velocity decreased at mid-term. INTERPRETATION: The unexpected lack of improvement in hip abductor moment from pre- to short-term may be caused by gait compensations that unload the hip. The increase in hip abductor moment beyond 3 years postoperatively underscores the benefits of an FDO into adolescence for independent ambulating individuals with cerebral palsy.

Long-term outcomes after selective dorsal rhizotomy: a retrospective matched cohort study.

AIM: To examine long-term outcomes of selective dorsal rhizotomy (SDR) 10 to 17 years after surgery. METHOD: Participants who underwent SDR had spastic diplegic cerebral palsy (CP), completed baseline gait analysis, and were 16 to 25 years old at follow-up. Non-SDR participants (i.e. controls) were matched on important clinical parameters at baseline but did not undergo SDR. All study participants completed six surveys assessing pain, quality of life, participation, function, and mobility. Treatment history for lower extremity surgery and antispasticity injections was tabulated. A subset of each study group returned for three-dimensional gait analysis, including kinematics, metabolic energy cost, and physical examination. Gait Deviation Index (GDI) was calculated to measure gait quality. RESULTS: The study cohort had 24 participants with SDR and 11 without SDR. Of these, 13 patients with SDR (five males, eight females; median [IQR] age 17y 2mo [16y 8mo-17y 9mo]) and eight without SDR (three males, five females; median [IQR] age 19y 2mo [17y 3mo-21y 11mo]) completed baseline and follow-up gait analysis. Spasticity significantly decreased in those with SDR (p<0.05). Gait Deviation Index improved more in participants without SDR than those with SDR (Δnon-SDR =12.8 vs ΔSDR =9.1; p=0.01). Compared with the SDR group, participants without SDR underwent significantly more subsequent interventions (p<0.05). INTERPRETATION: Patients in both the SDR and non-SDR groups showed improved gait quality more than 10 years after surgery. Participants without SDR had a larger improvement in gait pathology but underwent significantly more intervention. There were no differences between groups in survey measures. These results suggest differing treatment courses provide similar outcomes into early adulthood. WHAT THIS PAPER ADDS: Selective dorsal rhizotomy (SDR) and non-SDR groups had significant improvement in gait pathology over time. The non-SDR group had significantly better gait compared with the SDR group at follow-up. The groups had similar levels of energy cost, pain, and quality of life. Non-SDR participants underwent significantly more orthopaedic surgery and antispasticity injections than SDR participants. Use of a clinically similar control group highlights that different treatment courses may result in similar outcomes into young adulthood.

The effect of thoraco-lumbo-sacral orthosis wear time and clinical risk factors on curve progression for individuals with adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: The effectiveness of bracing with a thoraco-lumbo-sacral orthosis (TLSO) for adolescent idiopathic scoliosis (AIS) has been studied extensively, with a growing body of evidence supporting TLSO use. In this study we examine the effect of wear time and other important causal factors affecting curve progression and develop a risk model that can be applied to individual patients and is based on important casual factors. PURPOSE: Understand the impact of TLSO wear time and other risk factors in order to guide optimal treatment. STUDY DESIGN/SETTING: Prospective, multi-center, cohort study PATIENT SAMPLE: Individuals with a diagnosis of AIS, age of 10 to 16 years, primary Cobb angle of 20 to 45 degrees, Risser 0 to 2, <1 year post menarche if female, who were to be treated with a TLSO OUTCOME MEASURES: (1) Rate of primary curve progression, (2) surgery recommendation during TLSO treatment METHODS: Wear time was monitored with thermochrons. Participants were followed until the end of growth. We examined the causal effects of wear time and baseline skeletal maturity as measured by triradiate cartilage (TRC) status, Cobb angle, and age. We then fit an outcome prediction model (logistic regression) based on important casual factors. RESULTS: Our final cohort consisted of 145 individuals (baseline age 12.1-13.4 years). Wear time was an important cause of response to treatment, including an interaction with TRC status. Baseline Cobb angle and age were also meaningful causes of response. The prediction model was accurate (79%) and had good specificity (81%) and moderate sensitivity (68%) and an area under the receiver operating characteristic curve (AUC) of 0.81. Additionally, we were able to independently confirm previous estimates of treatment efficacy, with an odds ratio around 2.0. CONCLUSIONS: Our study showed the explicit causal effects of wear time, and baseline skeletal maturity, Cobb angle and age. The risk model we developed can be used for counseling patients and their families regarding TLSO wear and expectations for outcome.

American Society of Biomechanics Clinical Biomechanics Award 2021: Redistribution of muscle-tendon work in children with cerebral palsy who walk in crouch.

BACKGROUND: Previous study showed the triceps surae exhibits spring-like behavior about the ankle during walking in children with cerebral palsy. Thus, the work generated by the triceps surae is diminished relative to typically developing children. This study investigated whether the quadriceps offset the lack of triceps surae work production in children with cerebral palsy who walk in crouch. METHODS: Seven children with cerebral palsy (8-16 yrs) and 14 typically developing controls (8-17 yrs) walked overground at their preferred speed in a motion analysis laboratory. Shear wave tensiometers were used to track patellar and Achilles tendon loading throughout the gait cycle. Tendon force measures were coupled with muscle-tendon kinematic estimates to characterize the net work generated by the quadriceps and triceps surae about the knee and ankle, respectively. FINDINGS: Children with cerebral palsy generated significantly less triceps surae work when compared to controls (P < 0.001). The reverse was true at the knee. Children with cerebral palsy generated positive net work from the quadriceps about the knee, which exceeded the net quadriceps work generated by controls (P = 0.028). INTERPRETATION: There was a marked difference in functional behavior of the triceps surae and quadriceps in children with cerebral palsy who walk in crouch. In particular, the triceps surae of children with cerebral palsy exhibited spring-like behavior about the ankle while the quadriceps exhibited more motor-like behavior about the knee. This redistribution in work could partly be associated with the elevated energetic cost of walking in children with cerebral palsy and is relevant to consider when planning treatments to correct crouch gait.

Interobserver reliability of biplanar radiography is unaffected by clinical factors relevant to individuals at risk of pathological lower limb torsion.

BACKGROUND: Assessments of lower limb torsion are ubiquitous in clinical gait analysis practice as pathologic lower limb rotational deformity may contribute to gait abnormalities, anterior knee pain, as well as other debilitating conditions. Understandably, the overall utility of any torsional assessment is dependent on the measurement method's intrinsic accuracy, precision, and robustness to clinical interference factors. Recently, biplanar radiography (BPR) measurements of torsion have been shown to be both accurate and precise, but the robustness of BPR to potential interference factors is unknown. RESEARCH QUESTION: How robust are BPR lower limb torsional assessments to six potential interference factors: amount of torsion, skeletal maturity, radiograph quality, prior osteotomy, presence of implants, and observer training background and experience? METHODS: In this retrospective cohort study, four observers of diverse backgrounds and experience generated digital 3D reconstructions of 44 lower limbs using BPR images obtained during standard of care visits (age range 7-35 years). From each reconstruction, four lower limb torsional parameters were computed: femoral torsion, femorotibial rotation, tibial torsion, and transmalleolar axis equivalent. The mean absolute deviation (MAD) of each torsional parameter - calculated across the four observers - was used as the measure of reliability and tested against all interference factors. RESULTS: Results demonstrated that the average MAD was 2.1 degrees for femoral torsion, 3.0 degrees for transmalleolar axis equivalent, 3.8 degrees for femorotibial rotation, and 4.7 degrees for tibial torsion. None of the six potential interference factors were found to systematically influence BPR reliability across all four torsional parameters. Of the factors found to statistically influence one or more torsional parameter, none affected MAD values to a clinically meaningful extent. SIGNIFICANCE: In addition to being accurate and precise, BPR appears to be robust to several clinical factors relevant to children and young adults with or at risk for pathological lower limb torsion.

Medial Gastrocnemius Muscle Properties of Children With Cerebral Palsy After Different Tone Treatments: A Pilot Study.

OBJECTIVE: Spasticity in children with cerebral palsy can be managed by a spectrum of approaches, from conservative therapy, to temporary botulinum toxin A injections, to permanent transection of sensory nerves with a selective dorsal rhizotomy. This pilot study investigated whether these three tone management approaches are associated with histological and biochemical properties of the medial gastrocnemius. DESIGN: A convenience sample of children with cerebral palsy undergoing gastrocnemius lengthening surgery was enrolled. Intraoperative biopsies were obtained from three individuals (one each: minimal tone treatment; frequent gastrocnemius botulinum toxin A injections; previous selective dorsal rhizotomy). All individuals had plantarflexor contractures, weakness, and impaired motor control before the biopsy. RESULTS: Differences between participants were observed for muscle fiber cross-sectional area, fiber type, lipid content, satellite cell density, and centrally located nuclei. The most pronounced difference was the abundance of centrally located nuclei in the botulinum toxin A participants (52%) compared with the others (3-5%). Capillary density, collagen area and content, and muscle protein content were similar across participants. CONCLUSIONS: Several muscle properties seemed to deviate from reported norms, although age- and muscle-specific references are sparse. Prospective studies are necessary to distinguish cause and effect and to refine the risks and benefits of these treatment options.

The long-term effects of aggressive spasticity reducing treatment, including selective dorsal rhizotomy, on joint kinematic outcomes of persons with cerebral palsy.

BACKGROUND: Selective dorsal rhizotomy (SDR) creates a large and permanent reduction of spasticity for children with cerebral palsy (CP). Previous SDR outcomes studies have generally lacked appropriate control groups, had limited sample sizes, or reported short-term follow-up, limiting evidence for improvement in long-term gait function. RESEARCH QUESTION: Does aggressive spasticity management for individuals with CP improve long-term gait kinematics (discrete joint kinematics) compared to a control group of individuals with CP with minimal spasticity management? METHODS: This study was a secondary analysis - focused on joint-level kinematics - of a previous study evaluating the long-term outcomes of SDR. Two groups of participants were recruited based on a retrospectively completed baseline clinical gait study. One group received aggressive spasticity treatment including a selective dorsal rhizotomy (Yes-SDR group), while the other group had minimal spasticity management (No-SDR group). Both groups had orthopedic surgery treatment. Groups were matched on baseline spasticity. All participants prospectively returned for a follow-up gait study in young adulthood (greater than 21 years of age and at least 10 years after baseline). Change scores in discrete kinematic variables from baseline to follow-up were assessed using a linear model that included treatment arm (Yes-SDR, No-SDR), baseline age, and baseline kinematic value. For treatment arm, 5° and 5 Gait Deviation Index points were selected as thresholds to be considered a meaningful difference between treatment groups. RESULTS: At follow-up, there were no meaningful differences in pelvis, hip, knee, or ankle kinematic variable changes between treatment arms. Max knee flexion - swing showed a moderate treatment effect for Yes-SDR, although it did not reach the defined threshold. SIGNIFICANCE: Aggressive spasticity treatment does not result in meaningful differences in gait kinematics for persons with cerebral palsy in young adulthood compared to minimal spasticity management with both groups having orthopedic surgery.

Rasch analysis of items from two self-report measures of motor function: determination of item difficulty and relationships with children's ability levels.

AIM: The aim of this article was to determine item measurement properties of a set of items selected from the Gillette Functional Assessment Questionnaire (FAQ) and the Pediatric Outcome Data Collection Instrument (PODCI) using Rasch analysis, and to explore relationships between the FAQ/PODCI combined set of items, FAQ walking scale level, Gross Motor Function Classification System (GMFCS) levels, and the Gait Deviation Index on a common measurement scale. METHOD: Rasch analysis was performed on data from a retrospective chart review of parent-reported FAQ and PODCI data from 485 individuals (273 males; 212 females; mean age 9 y 10 mo, SD 3 y 10 mo) who underwent first-time three-dimensional gait analysis. Of the 485 individuals, 289 had a diagnosis of cerebral palsy (104 GMFCS level I, 97 GMFCS level II, 69 GMFCS level III, and 19 GMFCS level IV). Rasch-based person abilities and item difficulties based on subgroups defined by the FAQ walking scale level, Gait Deviation Index, and the GMFCS level were compared. RESULTS: The FAQ/PODCI item set demonstrated necessary Rasch characteristics to support its use as a combined measurement scale. Item groupings at similar difficulty levels were consistent with the mean person abilities of subgroups based on FAQ walking scale level, Gait Deviation Index, and GMFCS level. INTERPRETATION: Rasch-derived person ability scores from the FAQ/PODCI combined item set are consistent with clinical measures. Rasch analysis provides insights that may improve interpretation of the difficulty of motor functions for children with disabilities.

Quantifying alignment bias during the fabrication and fitting of ankle-foot orthoses: A single center study.

BACKGROUND: The sagittal plane alignment of ankle-foot orthoses (AFO) and AFO footwear combinations (AFO-FC) has been shown to influence gait outcomes. As such, clinicians often target a particular alignment during the fabricating and fitting of an AFO to maximize outcomes. RESEARCH QUESTION: How does the alignment of an AFO change during the fabrication and fitting process with respect to the intended, benchmark sagittal plane alignment identified by the consulting orthotist? STUDY DESIGN: Prospective METHODS: The assessment of AFO alignment was performed using a convenience sample of 125 custom molded AFOs from 68 individuals fabricated at our center (57 bilateral AFOs, 11 unilateral AFOs). The alignment of each AFO was measured at 5 distinct steps during the fabrication and fitting process using a recently validated method to measure AFO neutral angle using differential inclinometers. RESULTS: Prior to fabrication, the intended, benchmark alignment set by the consulting orthotist was 90 degrees for 92% of AFOs, was between 1 and 7 degrees of dorsiflexion for 7% of AFOs and was 5 degrees of plantarflexion for 1% of AFOs. Repeated measures ANOVA showed that AFO alignment changed between all fabrication and fitting steps. Overall, paired t-tests confirmed that AFO alignment was consistently 2-5 degrees more dorsiflexed than the benchmark alignment. Prior to fitting shoes, 55% of fabricated AFOs measured more than 2 degrees from the benchmark alignment. After fitting shoes, nearly 87% of AFO-FCs were more than 2 degrees from the benchmark alignment. SIGNIFICANCE: The finding of systematic dorsiflexion bias and changes in AFO alignment throughout the fabrication and fitting process indicates the need to improve AFO fabrication precision. The neutral angle measurement methodology - using differential inclinometers - provides a means to improve this precision by enabling orthotists to precisely quantify and make appropriate adjustments to AFO alignment throughout the entire fabrication and fitting process.