The effects of therapeutic vs. high-intensity ultrasound on the rabbit growth plate.

Six of 6-week-old NZ rabbits underwent ultrasound treatment using a therapeutic dose (0.5 W/cm(2)) and other six were treated with a higher dose (2.2 W/cm(2)) to the lateral aspect of the left knee joint for 20 min per day and a total of six weeks. The right knee joint served as a control. The goal of this study is to see if the therapeutic dose and high dose (approximately 45-fold therapeutic dose) will have toxic effects on the physis. Histological review appeared normal growth plate in the therapeutic group. In the high dosage group three of six cases displayed flattening of the distal femoral epiphysis and wedging of the proximal tibial plateau and indistinct growth plate lines. It is of interest to note that there are opening radiolucent area in the lateral aspect on the femoral metaphysis in five of six cases, where bone resorption has taken place. Histological results showed that there are disordered arrays of the cartilaginous cells in the proliferative zone. The height of the lateral physis in the high dose group is not only greater than that in the therapeutic dose (1083.8 vs. 500.3 micro m), but also greater than that in their contralateral control (530.7 micro m) (P<0.05). This short-term study demonstrates that high dose ultrasound has profound pathologic effects in growing bone. Therapeutic doses of ultrasound do not have an adverse effect on bone growth in the short-term follow-up.

Effects of trunk position on back surface-contour measured by raster stereophotography.

A study of the contour of the surface of the back was conducted using the Quantec spinal image system (QSIS; raster stereophotography) and the Vicon 3-dimensional (3-D) motion analysis system with a plaster model of the scoliotic spine. With postural changes in 3 dimensions came alterations in the surface shape of the back. Most changes in QSIS parameters occurred in the coronal plane. The study showed that model 1, with 9 degrees of Q angle (similar to Cobb angle in the coronal plane) in right thoracolumbar scoliosis, altered 3-D metrics less than model 2 did, with 54 degrees of Q angle in scoliosis. The change in the position of the trunk in the transverse plane had a more significant impact on the QSIS parameters. Raster stereophotography has been used clinically to monitor curve progression. Changes in transverse rotation of the trunk correlate significantly with variations in Q angle and axial rotation. Clinicians using a raster stereophotograph system to assess scoliotic deformity need to control postural sway, as doing so results in more stable and reproducible measurements that can be used for clinical follow-up.

Reproducibility of spinal back-contour measurements taken with raster stereography in adolescent idiopathic scoliosis.

200 children with a mean age of 12.7 years were measured with the Quantec Spinal Image System (QSIS), which uses computerized raster stereography technology. The aim of the study was to assess the intraobserver reproducibility of QSIS metrics in scoliosis patients and to quantify the effect of postural sway on the measurements. Children were randomly assigned to 1 of 2 groups: Group 1 contained 198 subjects, having 3 digitized measurements of 1 scan; Group 2 contained 200 subjects, undergoing 3 separate QSIS scans with 1 measurenent of each scan. Random-effects variance components models were fit to each outcome variable of interest (subject, scan or measurement) separately for the single scan dataset and the 3 scan dataset. They revealed that data from Group 2 contained greater reliability than data from Group 1 (reliability > or = 80%). The reliability of these parameters was perfect if one performed 3 scans and 3 measurements per scan. Results demonstrate that the QSIS with 3 scans and 1 measurement yields reproducible data from mild idiopathic scoliosis patients and that postural sway has minimal effect on data reproducibility.

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.

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.

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.

Correlation of foot radiographs with foot function as analyzed by plantar pressure distribution.

The goal of this study was to correlate radiographic measurements to the dynamic plantar pressure of the residual clubfoot. This was done by comparing radiographs and EMED plantar pressure results in 61 idiopathic clubfeet in 39 children at an average of 8 years after complete subtalar release. Radiographic measures were obtained using the standard method outlined by Simons, and pressure data were collected for eight regions of the foot. Pearson correlation analysis was performed and the most significant correlation was found between the calcaneal/first metatarsal angle in the lateral radiographic view (r = 0.72) and the midfoot contact area. In the anteroposterior view there was mild correlation between the talus/first metatarsal angle and both the peak pressure and plantar contact area. The results of this study indicate that radiographs used in concert with dynamic plantar pressure analysis will provide a more complete assessment of the corrected clubfoot.