Growth-preserving instrumentation in early-onset scoliosis patients with multi-level congenital anomalies

Study design: Retrospective. Objectives: To assess final outcomes in patients with early-onset scoliosis (EOS) who underwent growth-preserving instrumentation (GPI). Summary of background data: Various types of growth-preserving instrumentation (GPI) are frequently employed, but until recently had not been utilized long enough to assess final outcomes. Methods: GPI �graduates� with multi-level congenital curves were identified. Graduation was defined as a final fusion or 5 years of follow-up without planned future surgeries. Outcomes included radiographic parameters and complications. Results: 26 patients were included. 11 had associated diagnoses; eight had fused ribs. 17 were treated with traditional growing rods, seven with vertically expandable prosthetic ribs, and two with Shilla procedures. The mean GPI spanned 12.3 levels including 10.7 motion segments, age at index surgery was 5.5 years, treatment spanned 7.5 years, and follow-up was 9.2 years. 24 patients underwent final fusion. Mean major curve decreased from 73° to 49° with index surgery (p ' 0.01) and remained unchanged through a final follow-up. Final major curve was ' 40° in 9 patients (35), 40°�60° in 11 patients (42), and ' 60° in 6 patients (23). None worsened throughout treatment. Mean T1�T12 height increased 2.4 cm with index surgery (p = 0.02) and 5.4 cm total (p ' 0.01). T1�T12 height increased in all patients and was ultimately ' 18 cm in 10 patients (38), 18�22 cm in 10 patients (38), and ' 22 cm in 6 patients (23). On average, there were 2.6 complications per patient, including 1.7 implant failures. 12 patients (46) experienced � 3 complications; four patients (15) experienced none. Conclusion: We observed successful prevention of deformity progression but substantial residual deformity among GPI graduates with multi-level congenital EOS. Most coronal curve correction was attained during GPI implantation; thoracic height improved throughout treatment. While some favorable results were found, treatment strategies allowing improved deformity correction would be valuable for this challenging population. Level of evidence: Therapeutic-III. © 2020, Scoliosis Research Society

Modelagem da infiltração de água no solo sob condições de estratificação utilizando-se a equação de Green-Ampt Modeling of water infiltration in soil under stratified conditions using the Green-Ampt equation

A infiltração de água no solo é um dos mais significantes processos do ciclo hidrológico. A equação de Green-Ampt (GA) é bastante utilizada na modelagem da infiltração; entretanto, diversos autores alertam para a necessidade de adequação de seus parâmetros de entrada (umidade de saturação (tetas); condutividade hidráulica do solo saturado (K0) e potencial matricial na frente de umedecimento (psi). Neste sentido, avaliou-se a aplicabilidade do modelo de GA, assim como as diversas proposições de adequação de K0 e psi, em um Latossolo Vermelho-Amarelo sob condições de estratificação. Determinaram-se a infiltração acumulada (I), a taxa de infiltração (Ti) e as características físicas do perfil necessárias para a aplicação do modelo. Foram feitas simulações com base na combinação de seis metodologias para a determinação de psi e três para a condutividade hidráulica da zona de transmissão (Kw), verificando-se que as combinações seguintes simularam bem o processo de infiltração: Kw igual a 0,5 K0 associado a psi determinado com base na umidade inicial do solo (psi (tetai)); Kw igual à taxa de infiltração estável (Tie) associado a psi igual à média entre psi (tetai) e psi relativo à umidade de saturação de campo (psi (tetaw)); e Kw igual a K0 associado a psi calculado com base na textura e porosidade do solo (psi(textura)) e Kw igual à Tie associado a psi(textura).<br>Soil water infiltration is one of the most important processes of the hydrological cycle. The Green and Ampt equation (GA) is quite used to simulate the infiltration process, however, several authors showed the necessity of some adaptations in the GA parameters: saturation moisture (thetas), hydraulic conductivity (K0) and mean suction in the wetting front (psi). An evaluation was made of the GA model and of the several correction propositions of K0 and psi, applied in a stratified Red-Yellow Latosol. A soil box filled with soil material belonging to three horizons of the studied soil was used. The accumulated infiltration (I), infiltration rate (Ti), as well as the physical characteristics of the profile needed for the application of the model were determined. Simulations based on the combination among six methodologies for the determination of psi was made and three for the determination of hydraulic conductivity in the transmission zone (Kw). The following combinations simulated well the infiltration process: Kw equal to 0,5 K0 associated to psi relative to the initial moisture content (psi(thetai)); Kw equals to the stable infiltration rate (Tie) associated to psi equal to the mean among psi (thetai) and psi relative to the saturation field moisture (psi (thetaw)); Kw equal to K0 associated to psi calculated with base in the texture and porosity of the soil and Kw equal to Tie associated to psi calculated on the basis of texture and porosity of the soil