RESUMO
OBJECTIVES: The aims of the present study were to monitor, by radiographic examination, the skeletal development of the pelvis and the femorotibial joints of the domestic cat from the first week of life until the closing of the growth plates. METHODS: Radiographic examinations were collected from 15 domestic cats at weekly intervals during the first month and every 2 weeks from the second to the fourth month of age. After that, examinations were performed monthly until the age of 18 months. RESULTS: The ischiopubic growth plate closed at 2 months of age, followed by the fusion of the iliopubic, ilioischial, proximal femoral, greater trochanter and proximal fibular growth plates. The distal femur and proximal tibial growth plates were the last to close, with fusion occurring at 18 months. The mean time to closure of the iliopubic, ilioischial and distal femoral growth plates was shorter in females. The ossification centers first appeared, in ascending order, beginning with the lesser trochanter, followed by the greater trochanter, proximal fibular epiphysis, tibial tuberosity, patella, ischial tuberosity and lateral sesamoid of the popliteus muscle. CONCLUSIONS AND RELEVANCE: The complete closure of the growth plates of domestic cats occurs at approximately 18 months of age. Skeletal maturation at approximately 18 months of age is an important parameter to be considered in radiographic evaluation of certain skeletal changes, evolution of fractures and nutritional imbalance.
Assuntos
Gatos/crescimento & desenvolvimento , Fíbula/crescimento & desenvolvimento , Articulação do Quadril/crescimento & desenvolvimento , Articulações/crescimento & desenvolvimento , Pelve/crescimento & desenvolvimento , Radiografia/veterinária , Tíbia/crescimento & desenvolvimento , Animais , Feminino , Fíbula/diagnóstico por imagem , Articulação do Quadril/diagnóstico por imagem , Articulações/diagnóstico por imagem , Masculino , Pelve/diagnóstico por imagem , Tíbia/diagnóstico por imagemRESUMO
Measurement of the Southwick's anteroposterior (AP) angle (shaft epiphysis proximal femoral AP angle) is not only a useful tool for planning the surgical treatment of deformities caused by slipped capital femoral epiphysis, but seems to be also important for recognizing the risk of epiphysiolysis development in obese patients (increased AP angle) or to confirm the diagnosis of slipped capital femoral epiphysis (decreased AP angle). To establish normal reference values of the Southwick's AP angle, we studied 97 normal nonobese adolescents (42 females, 55 males), with ages ranging between 8 and 16 years. The mean (SD) AP angle was 151.2 (5.0), ranging from 140 to 164. The limits for the first (p25) and third (p75) quartiles were 148 and 155, respectively. No difference was observed in the AP angle in males when compared with females. The AP angle was evaluated according to sex, chronological age, bone age, weight, height, and pubertal stage of development. We observed an inverse correlation of the AP angle with chronological age (r=-0.57) and bone age (r=-0.52). A weak inverse correlation was also found with stature (r=-0.33). Only a tendency toward an inverse correlation with weight (r=-0.27) or body mass index (r=-0.26) was observed. No significant correlation with the pubertal stage was found. When chronological and bone ages were divided into intervals, a significant reduction of the AP angle was observed only in patients older than 14 years compared with those younger than 10 years of age. In this study, we propose that the AP angle should be considered to be normal if it varies between 148 and 155. We conclude that the normal AP angle does not depend on sex; however, it tends to decrease with stature, and chronological and bone ages. In the normal weight range also, the AP angle decreases, contrasting with our previous findings in obese adolescents, in which the AP angle increases with the severity of obesity.