Channing Tassone

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.

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.

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.

A New Method in the Design of a Dynamic Pedorthosis for Children With Residual Clubfoot

Clubfoot is a common pediatric orthopaedic deformity. Despite the popularity of Ponseti’s method and night splints such as the Denis–Browne method, there is still an 11–47% rate of deformity relapse reported in the literature. The technique to make traditional orthotics is dependent on a nonweight-bearing casting or foot imprint. These splints outdate clinical treatment trends and only apply to patients who are of nonwalking age. This study shows that a new procedure utilizing computer aided design and the finite element method can be employed to develop a customized weight-bearing dynamic orthotic. In addition, the plantar pressure distribution and the trajectory of the center of this pressure distribution are used to design the orthotic. It is shown that the trajectory of the center of pressure, traditionally used in gait analysis, can be used not only to quantify the severity of the foot deformity but to design a custom orthotic as well. Also, the new procedure allows the custom orthotic to be designed and analyzed within a day. The new orthotic design is composed of soft foam interior layers and a polymer supportive exterior layer. It is proved that rapid prototyping technologies employing selective laser sintering can be used to construct these layers to produce a custom orthotic within a 24 h time frame.

A line of zebrafish with development of abnormal spinal curvatures

Methods Potential founder fish with spinal curvatures were outcrossed with a wild type zebrafish line (AB) and the resulting siblings (F1 generation) crossed and the offspring (F2 generation) examined for signs of spinal curvature beginning at 14 days post fertilization (dpf). Spinal curvatures of the affected fish were visualized using either a Faxitron or by Alizarian red staining of the skeletons and the curvature measured from the resulting images in the thoracic, thoracolumbar, or lumbar regions. Affected and normal zebrafish were fixed, embedded, section and stained with hemotoxylin and eosin.

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.

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

BackgroundNumerous 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.MethodsA total of 23 standardized tensile tests were performed on the Delta-Cast Soft® and 3MTM ScotchcastTM 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.ResultsIt 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.ConclusionsBased 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.

Newly Designed Foot Orthosis for Children with Residual Clubfoot After Ponseti Casting

ABSTRACT Orthoses can be used to accommodate residual clubfoot after Ponseti casting. Traditionally, orthoses are constructed using nonweightbearing casts or foam imprints. Technological advances in pressure analysis and in three-dimensional (3D) geometry assessment by computed tomographic (CT) scans can assist in designing and fabricating orthoses. The purpose of this study was to validate the new Milwaukee Foot Orthosis (MFO) using pressure metrics. Five typically developing children (mean age of 7.2 years) and five children with residual clubfoot deformities (eight residual clubfeet and mean age of 6 years) were recruited. All children with residual clubfoot had undergone Ponseti casting as an initial treatment. Each child underwent plantar pressure measurements and acquisition of 3D foot dimensions by a CT scanner. A computer-aided design (CAD) was used to develop a customized MFO for each of the five children. The MFO was manufactured for each foot with residual deformities using a rapid prototyping system. After the use of the MFO, pressure data showed significant reduction of maximal force, peak pressure, and other measurements at the heel and the lateral forefoot. There was significant reduction of the center of pressure (CoP) deviation in the forefoot (7.9%) and the midfoot (4.0%) compared with barefoot. The new MFO is effective in reducing residual clubfoot deformities, such as supination and adduction.

Impact of manual therapy in children with Adolescent Idiopathic Scoliosis

Methods We recruited 11 children with AIS, with a mean age of 14 years of age. Children with AIS who received manual therapy and the motor relearning approach were followed for an average of 4.5 months. Physical therapy intervention consisted of 60-minute treatment sessions two times per week. An impairment-based manual physical therapy method was utilized, consisting of passive force application and specific mobilization and manipulation techniques along planes of movement parallel or perpendicular to the anatomic planes of joint surfaces. Our motor relearning approach consisted of a segmentation approach to postural control, performed during specific functional and exercise-based tasks. The 3-dimensional back contour was measured using the Milwaukee Topographic System (MTS) before and after the therapy. The Wilcoxon Sign Rank test was used for comparison of muscle strength and 3-dimensional back contour variables before and after the therapy.

Correlation between anatomic foot and ankle movement measured with MRI and with a motion analysis system.

Several studies have attempted to measure how well external markers track internal bone movement using pins drilled into the foot, but this is too invasive for the pediatric population. This study investigated how well a six segment foot model (6SFM) using external markers was able to measure bone movement in the foot compared to MRI measurements. The foot was moved into different positions using a plastic foot jig and measurements were taken with both systems. The aims were to: (1) Look at the correlation between movement tracked with an Electronic Motion Tracking System (EMTS) and by measurements derived from MRI images, specifically the principal intercept angles (PIAs) which are the angles of intersection between principal axes of inertia of bone volumes. (2) To see how well external motion measured by the 6SFM could predict PIAs. Four bone pairs had their movement tracked: Tibia-Calcaneus, Calcaneus-Cuboid, Navicular-1st Metatarsal, and 1st Metatarsal-Hallux. The results showed moderate correlation between measured PIAs and those predicted at the Tibia-Calcaneus, Navicular-1st Metatarsal, and 1st Metatarsal-Hallux joints. Moderate to high correlation was found between the PIA and movement in a single anatomic plane for all four joints at several positions. The 6SFM using the EMTS allows reliable tracking of 3D rotations in the pediatric foot, except at the Calcaneus-Cuboid joint.