Correlation of transverse rotation of the spine using surface topography and 3D reconstructive radiography in children with idiopathic scoliosis.

PURPOSE: The relationship between axial surface rotation (ASR) measured by surface topography (ST) and axial vertebral rotation (AVR) measured by radiography in the transverse plane is not well defined. This study aimed to: (1) quantify ASR and AVR patterns and their magnitudes from T1 to L5; (2) determine the correlation or agreement between the ASR and AVR; and (3) investigate the relationship between axial rotation differences (ASR-AVR) and major Cobb angle. METHODS: This is a retrospective study evaluating patients (age 8-18) with IS or spinal asymmetry with both radiographic and ST measurements. Demographics, descriptive analysis, and correlations and agreements between ASR and AVR were evaluated. A piecewise linear regression model was further created to relate rotational differences to Cobb angle. RESULTS: Fifty-two subjects met inclusion criteria. Mean age was 14.1 ± 1.7 and 39 (75%) were female. Looking at patterns, AVR had maximal rotation at T8, while ASR had maximal rotation at T11 (r = 0.35, P = .006). Cobb angle was 24.1° ± 13.3° with AVR of - 1° ± 4.6° and scoliotic angle was 20.9° ± 11.5° with ASR of - 2.3° ± 6.6°. (ASR-AVR) vs Cobb angle was found to be very weakly correlated with a curve of less than 38.8° (r = 0.15, P = .001). CONCLUSION: Our preliminary findings support that ASR measured by ST has a weak correlation with estimation of AVR by 3D radiographic reconstruction. This correlation may further help us to understand the application of transverse rotation in some clinical scenarios such as specific casting manipulation, padding mechanism in brace, and surgical correction of rib deformity.

3D Back Contour Metrics in Predicting Idiopathic Scoliosis Progression: Retrospective Cohort Analysis, Case Series Report and Proof of Concept.

Adolescent Idiopathic Scoliosis is a 3D spinal deformity commonly characterized by serial radiographs. Patients with AIS may have increased average radiation exposure compared to unaffected patients and thus may be implicated with a modest increase in cancer risk. To minimize lifetime radiation exposure, alternative imaging modalities such as surface topography are being explored. Surface topography (ST) uses a camera to map anatomic landmarks of the spine and contours of the back to create software-generated spine models. ST has previously shown good correlation to radiographic measures. In this study, we sought to use ST in the creation of a risk stratification model. A total of 38 patients met the inclusion criteria for curve progression prediction. Scoliotic curves were classified as progressing, stabilized, or improving, and a predictive model was created using the proportional odds logistic modeling. The results showed that surface topography was able to moderately appraise scoliosis curvatures when compared to radiographs. The predictive model, using demographic and surface topography measurements, was able to account for 86.9% of the variability in the future Cobb angle. Additionally, attempts at classification of curve progression, stabilization, or improvement were accurately predicted 27/38 times, 71%. These results provide a basis for the creation of a clinical tool in the tracking and prediction of scoliosis progression in order to reduce the number of X-rays required.

Long-term follow-up of children with a surgically treated clubfoot: Assessing the multi-segment-foot motions, dynamic plantar pressures, and functional outcomes.

OBJECTIVE: The purpose of this study was to compare surgically treated clubfoot with typically developing (TD) children using plantar pressure, multi-segment-foot kinematic analysis, and multiple functional outcomes in comprehensive and long-term study. Methods: 26 patients with 45 clubfeet and 23 TD children with 45 normal feet were evaluated. Most clubfoot patients had a complete subtalar release and a few patients had a posterior medial-lateral release at the mean age of 5 years and 6 months. The mean age at follow-up for clubfoot was 12 years and 5 months. Subjects underwent physical and radiographic examination, plantar pressure analysis, multi-segment-foot motion analysis, AAOS Foot & Ankle Questionnaire (AAOS-FAQ), the Pediatric Outcomes Data Collection Instrument (PODCI), and the Child Behavior Checklist (CBCL). RESULTS: Clubfoot patients scored significantly worse than TD on the AAOS-FAQ (90.9 vs.99.9 for pain and comfort), the CBCL Problems scale (23.1 vs.6.3), and several subscales of the PODCI (86.5 vs.96.7 for Sports and Physical Functioning) (P<0.05). Peak pressure at the lateral heel (25.6 vs.29.6 N/cm2), contact area at the 1 st metatarsal head (1 st MT) (6.0 vs. 7.2 cm2) and the pressure time integral at the 1 st MT (5.2 vs. 11.0 N/cm2 ∗ s) were significantly lower for the clubfoot group compared to the TD foot group (P<0.05). Maximum dorsiflexion of the 1 st metatarsal-hallux (1 st MT-Hal) (17.5° vs. 34.8°) during stance phase (ST), supination of the 1 st MT-Hal during swing phase (SW) (4° vs. 7°), maximum plantarflexion of the ankle during ST (-6.8° vs.-11.2°), and maximum varus of the ankle during SW (4.4° vs. 6.9°) were also lower for clubfoot except for maximum dorsiflexion of the navicular-1 st MT (P<0.05). CONCLUSION: This study supports evidence that surgically treated clubfoot continues to have residual deformity of forefoot, overcorrection of hindfoot, stiffness, and a decrease in physical functioning. This comprehensive study accurately portrays postsurgical clubfoot function with objective means through appropriate technologies. A plantar pressure redistributed and finite element analysis designed orthosis may be of importance in the improvement of the foot and ankle joint function for ambulatory children with a relapse of clubfoot deformity.

Reliability of Three-Dimensional Spinal Modeling of Patients With Idiopathic Scoliosis Using EOS System.

STUDY DESIGN: Three-dimensional (3D) spinal models of children with idiopathic scoliosis (IS) were created using the EOS imaging system (EOS) and sterEOS software. OBJECTIVE: To determine the inter- or intraobserver reproducibility of the 3D spinal models in children with IS of different apex locations. SUMMARY OF BACKGROUND DATA: 3D spinal model measurements include the Cobb angle, kyphosis, lordosis, and axial vertebral rotation (AVR). Variation of these measurements between two investigators and two different trials by the same investigator were analyzed by inter- and intraclass correlation coefficients (ICCs). METHODS: Biplanar radiographic images of 15 patients (age: 6-15 years) with IS were uploaded into the sterEOS software. Spinal and pelvic markers were manually identified to construct a 3D spinal model and measure spinal parameters. Two trained examiners independently performed modeling and performed modeling in spaced out trials. The ICC between inter- and intraobservers were calculated. RESULTS: ICCs between inter- and intraobservers were significant for all parameters (p < .05). Both the inter- and intraobservers showed excellent agreement for the Cobb angles in the thoracic segment, kyphosis and lordosis. Substantial interobserver agreement and excellent intraobserver agreement were determined for the Cobb angle in the thoracolumbar or lumbar (TL/L) segment, with less than 6° difference between two raters and less than 2° difference between two trials. Substantial interobserver agreement for the AVR in the TL/L region and substantial interobserver agreement for the AVR in the thoracic region were found, with less than 4° difference between raters. One rater had substantial intraobserver agreement for the AVR in the TL/L region whereas another rater reported moderate to substantial intraobserver agreement in both the thoracic and TL/L regions, with less than 3° difference between trials. CONCLUSION: The EOS system shows reliable and repeatable results in 3D spinal modeling of children with IS. LEVEL OF EVIDENCE: Level III.

Long-Term Effects of Orthoses Use on the Changes of Foot and Ankle Joint Motions of Children With Spastic Cerebral Palsy.

BACKGROUND: Orthoses commonly are prescribed to children with cerebral palsy (CP) to provide foot correction and to improve ambulatory function. Immediate effects of ankle foot orthosis (AFOs) have been investigated, but long-term kinematic effects are lacking clinical evidence. OBJECTIVE: To determine changes in 3-dimensional ankle and foot segment motion in pediatric patients with CP between initial and follow-up visits (18-month average time differences) in both barefoot gait and gait with their AFO. We also investigated intravisit changes between barefoot and AFO gait. DESIGN: A prospective cohort study. SETTING: Children's Hospital of Wisconsin, Department of Orthopaedic Surgery, Medical College of Wisconsin. PATIENTS: A total of 23 children with CP, mean age 10.5 years (6.2-18.1 years) were clinically prescribed either a solid ankle foot orthotic (SAFO), hinged ankle foot orthotic (HAFO), or supramalleolar orthotic. METHODS: Holes were cut in the study orthoses so that electromagnetic markers could be directly placed on the skin. A 6-foot segment model was used. OUTCOME MEASUREMENTS: Kinematic and kinetic data were recorded for each patient's initial and follow-up visit (18-month follow-up average, 15-20 months range). RESULTS: For the SAFO group (gait with AFO), a significant decrease in dorsiflexion was found between the initial and third visit (P = .008). Furthermore, the SAFO group (barefoot gait) had an increased eversion at the midfoot for most of the gait cycle (P < .008). Sagittal forefoot range of motion was reduced for all 3 groups between the barefoot and AFO groups. CONCLUSION: The use of AFOs long term either maintained or improved foot deformities or dysfunction. LEVEL OF EVIDENCE: Level II.

Comparison of biomechanical behavior between a cast material torso jacket and a polyethylene based jacket.

BACKGROUND: Numerous designs are used to the treatment of Early Onset Scoliosis. For example, a Thoraco-Lumbo-Sacral Orthosis (TLSO) is constructed using Polyethylene (PE). In addition, a series of castings has been implemented using cast material (3M, BSN Medical). The cast material has some significant advantages over the PE design including: growth preserving, improved compliance, decreased invasiveness, delaying or avoiding surgery, and the ability to allow the skin to breathe. However, the mechanical effectiveness of the cast material brace as compared to the TLSO is unknown, thus providing the objective of this study. METHODS: A total of 23 standardized tensile tests were performed on the Delta-Cast Soft(®) and 3M(TM) Scotchcast(TM) Plus Casting Tape in order to obtain mechanical properties (Young's and shear moduli and Poisson ratios). Using a radiograph of a thoracic spine, the size of twelve vertebrae and eleven intervertebral discs were measured and used to create a finite element spine model. Simulations using this model were used to establish mechanical loads which were then applied to finite element models of the TLSO and cast jacket. The thicknesses and number of material layers was varied in these models. Multiple simulations were performed. RESULTS: It was found that a 6.6.mm thick cast jacket made of Delta-Cast Soft(®) had a maximum deformation of 4.7 mm, a maximum stress of 2.9 MPa and a structural factor of safety of 5.71. On the other hand, a 4 mm thick jacket made of PE had a maximum deformation of 2 mm, a maximum stress of 8.9 MPa and a structural factor of safety of 2.70. The cast jacket was 3.5 times lighter and had a material of cost 1/5 of the PE brace. CONCLUSIONS: Based on the results, either design will generate the proper constraint forces to maintain spinal correction. But, based on the design parameters (thickness, mechanical properties, structural factor of safety and cost) the brace made of cast material, though slightly thicker has superior structural and cost benefits. Thus, from the biomechanical point of view, the cast brace is more efficient than the PE brace.

Foot and ankle joint movements inside orthoses for children with spastic CP.

We compared the ankle joint and foot segment kinematics of pediatric cerebral palsy (CP) participants walking with and without orthoses. A six segment foot model (6SF) was used to track foot motion. Holes were cut in the study orthoses so that electromagnetic markers could be directly placed on the skin. The Hinged Ankle Foot Orthoses (HAFO) allowed a significant increase in ankle dorsiflexion as compared to the barefoot condition during gait, but significantly constrained sagittal forefoot motion and forefoot sagittal range of motion (ROM) (p < 0.01), which may be detrimental. The Solid Ankle Foot Orthoses (SAFO) constrained forefoot ROM as compared to barefoot gait (p < 0.01). The 6SF model did not confirm that the SAFO can control excessive plantarflexion for those with severe plantarflexor spasticity. The supramalleolar orthosis (SMO) significantly (p < 0.01) constrained forefoot ROM as compared to barefoot gait at the beginning and end of the stance phase, which could be detrimental. The SMO had no effects observed in the coronal plane.

Reproducibility of newly developed spinal topography measurements for scoliosis.

OBJECTIVE: In an effort to limit exposure to ionizing radiation and fully characterize three dimensional changes in the spine of patients with scoliosis reliable non-invasive methods of spinal back contour analysis (Milwaukee Topographic Scanner) (MTS) have been developed. STUDY DESIGN: The current study compares spinal topography measurements among different subject positions and evaluates the reproducibility of the system for both inter-rater and intra-rater reliability. METHODS: A dummy cast (plastic cast) of one patient with adolescent idiopathic scoliosis was created in order to test the reliability of the MTS. The dummy cast was positioned and rotated in 3D while scanned by two investigators using the MTS. A total of twelve parameters including Q-angle (an analog to X-ray's Cobb angle) were extracted. RESULTS: All measurements of intra-rater and inter-rater reliability were excellent (Intraclass Correlation Coefficients ranging from 0.89 to 0.99) with the exception of Pelvic Tilt (intra-rater ICC is 0.61) and lordosis angle (inter-rater ICC is 0.82). No significant variability among investigators was observed for all tested metrics. No significant variability due to position was observed for the majority of back contour measurements but there were significant changes in the T1-S1 angle, T1-S1 deviation, T1-NC angle, T1-NC deviation, and Back Height metric (p< 0.05). CONCLUSIONS: The MTS is a reliable method of raster stereography in the measurement of the back contour, which will help monitor the progression of children with idiopathic scoliosis and reduce the use of X-rays.

Insole-pressure distribution for normal children in different age groups.

BACKGROUND: In measuring plantar pressures during gait, earlier methods have used a platform system that does not take into account the interactions feet have with orthotics and shoe wearing. The purpose of the study was to provide normal insole plantar pressure parameter data during stance phase using the Pedar pressure insole system. METHODS: Twenty-nine normal children, age 6 to 16 years, were recruited and walked along the 25 m walkway at self-selected speeds. Patients were divided into 2 separate groups for statistical analysis--juniors (< 12 y old) and teenagers (> 13 y old). The pressure map was divided into 8 regions (masks) determined by anatomic landmarks and a total of 7 pressure parameters were analyzed of each mask. RESULTS: We did not detect significant differences in foot pressures between juniors and teenagers when regarding sex, or left and right feet for 7 parameters measured. CONCLUSIONS: This normative data will provide a basis with which to more accurately assess pediatric pathologic foot deformities and to distinguish dynamic foot deformities from anatomic foot deformities. THE LEVEL OF EVIDENCE: Level II.

Creation and implementation of a prospective pediatric clinical outcomes registry.

OBJECTIVE: To build a pediatric clinical outcomes registry (COR) using a contemporary information system designed to support research and outcome studies and to improve patient care and quality of life. PATIENTS AND METHODS: In response to physician needs, this process was implemented: 1) database needs assessment survey, 2) evaluate existing systems and vendors, 3) pilot test a COR tool, and 4) build a COR. The COR was designed to include patients with the following conditions: scoliosis, neonatal surgery, urologic surgery, cleft palate, pain management, otitis media, and voice and airway problems. Agency for Healthcare Research and Quality methodology was followed to create the infrastructure and registry. RESULTS: The database needs assessment survey was completed by 99 individuals and most respondents wanted to collect more standardized data than currently available in existing systems. Satisfaction with the existing systems was rated low. The COR was created and a pilot test was successful. The COR was implemented and has been functioning for more than 2 years. CONCLUSIONS: By identifying physicians needs, evaluating existing technology and incorporating a multidisciplinary team, the COR was created and implemented to maintain clinical data on a variety of patient diagnoses and outcomes using a single technology platform that enhances potential research collaborations and minimizes redundant data entry and data collection, such as quality of life assessments for the patients.

MRI pathoanatomy study of congenital vertical talus.

BACKGROUND: Prior reports regarding the pathologic anatomy for congenital vertical talus have noted some disagreement as to which elements of the pathologic anatomy are consistently present. The purpose of his study is to evaluate the 3-dimensional morphologic changes and pathoanatomy of the congenital vertical talus using magnetic resonance imaging. METHODS: Nine patients with congenital vertical talus (ranging from 5 mo-11 y) underwent magnetic resonance imaging of both feet. A foot and ankle coil was used for the 1.5 T system. The protocol consisted of T1-weighted spin echo sequence image and T2-weighted fast spin echo sequence image in the sagittal, coronal, and axial planes. Slice thickness ranged from 3 to 4 mm with 0 to 1.0 mm interspace thickness. A descriptive analysis was performed based upon the T1-weighted image by physicians. RESULTS: At the level of the talonavicular joint, the navicular was seen significantly subluxed dorsally with associated wedging of the navicular. At the level of the calcaneocuboid joint, often there was a significant dorsal subluxation of the cuboid in relation to the calcaneus. Lateral obliquity of the calcaneocuboid joint could be present to varying degrees. The anterior calcaneus was significantly laterally displaced in relation to the talar head with an element of lateral translation and eversion of the calcaneus at the subtalar joint. Distal cavus at the cuneiform-first metatarsal joint was observed in 5 patients. CONCLUSIONS: This study suggests that there is significant pathology at the level of subtalar joint in congenital vertical talus. In addition to satisfactory reduction of the talonavicular joint, methods to ensure realignment of the calcaneus under the talus may be a crucial component of deformity correction and to prevent recurrence of deformity. LEVEL OF EVIDENCE: A Level III diagnostic study using normal pediatric foot anatomy in magnetic resonance imaging as a reference.

Use of flexible intramedullary nail fixation in treating femur fractures in children.

We evaluated use of flexible intramedullary nails in the surgical treatment of femoral shaft fractures in 135 children (138 fractures). Mean age was 9.7 years (range, 2-17 years). Mean follow-up was 15.6 months (range, 6.6-53.5 months). Seventy-two patients were treated with stainless-steel (Ender) nails and 66 with titanium elastic nails. There were 73 midshaft fractures, 48 proximal-third fractures, and 17 distal-third fractures. Fracture patterns were transverse (66), oblique (42), spiral (24), and comminuted (6). There were 16 complications--3 refractures, 2 delayed unions, 3 varus or valgus malalignments, 5 nail-tip irritations, 2 broken interlocking screws (found incidentally on radiographs), and 1 asymptomatic proximal nail migration--for a complication rate of 11.7%. These results demonstrate that use of flexible intramedullary nails in the treatment of femoral shaft fractures in children is successful regardless of patient age, fracture location, or fracture pattern.

The effect of instrumentation with different mechanical properties on the pig spine during growth.

The effect off mechanically altered bone on spinal growth using instrumentations with different mechanical properties is quantified through the use of experimental tests. Eight spine segments from three female pigs weighing 60 90 lb were subjected to a continuous tensile force. The load (0 - 400 N) was applied using a MTS Alliance RT/50 machine and the resulting extension recorded using an extensometer. Displacements between the screws were measured in control without implant, metal plate system, and spring system, respectively. It is shown that the addition of an implant will increase the stiffness of the spine, which will affect the extension of the spine and hence hinder growth in the spine.

Dynamic plantar pressure measurement for the normal subject: Free-mapping model for the analysis of pediatric foot deformities.

In measuring plantar pressures during gait, prior methods have divided the foot into five regions and neglected forefoot alignment as it is involved in intoeing and outtoeing. The authors' proposed free-mapping method divides the foot into nine regions and incorporates a pedobarograph foot progression angle. The purpose of the study was to provide normal pressure parameter data during stance phase using a free-mapping model. Sixty-six normal children, ages 6 to 16 years, were recruited and walked along the 5-m walkway at self-selected speeds. The mean and standard deviation for the plantar contact area, contact time, peak pressure, maximal mean pressure, pressure-time integral, force-time integral, instant of peak pressure, and instant of maximum force in nine foot regions are reported. These normative data will provide a basis with which assessment of foot deformities involved in clubfoot, pes planus, and cavus foot will be more accurately defined.