Deformity of the femoral head following vascular infarct in piglets

Abstract

Background In Legg-Calvé-Perthes disease (LCPD), 4 major patterns (coxa plana, coxa magna, coxa vara, subluxation) of the femoral head are commonly observed. However, direct observation of pathological specimens is rarely possible. An animal model of LCPD may clarify the pathogenesis of femoral head deformity.Animals and methods In 26 piglets, we interrupted the vascular supply to the capital femoral epiphysis by cutting the ligamentum teres and ligating the femoral neck containing the epiphyseal artery. 6-7 piglets in each experimental group were killed at early (2 and 4 weeks: P2 and P4), intermediate (12 weeks: P12), and late (20 weeks: P20) periods. We examined the extracted femoral heads macroscopically and radiographically.Results The mean decrease in epiphyseal height was 1.5 mm, 4.1 mm, 5.0 mm, and 7.5 mm in P2, P4, P12 and P20, respectively (rs = 0.76, p = 0.002). The mean increase of diameter was 4.1 mm, 6.9 mm, and 6.8 mm in P4, P12 and P20, respectively. Decrease of the articulotrochanteric distance was mild in P2 and P4, and severe in P12 and P20. Subluxation of the femoral head was observed only in P12 and P20 piglets.Interpretation The piglet model of LCPD was useful in the early stage of devascularization for investigation of the developmental pattern of femoral head deformity. However, when the piglets had grown to 20 weeks old or more-that is, to full skeletal maturity-the femoral head and acetabulum showed severe deformities that were most likely caused by heavy body weight.

Animal Models of Osteonecrosis

“…This was associated with a dramatic increase in VEGF expression in the epiphyseal cartilage surrounding the bony epiphysis [18]. Using a similar model (cutting the ligamentum teres, ligating the femoral neck), Rowe et al [20] evaluated the femoral head pathology for up to 20 weeks. They observed a decrease in epiphyseal height, which increased in magnitude over time.…”

“…Rowe et al [20] Cutting the ligamentum teres, ligating the femoral neck 4-5-week-old piglets Zahir et al [11] Sanchis et al [10] Hip dislocation and coagulation 1-month-old puppies Kamegaya et al [15] Electrocoagulated epiphyseal artery and subluxation and dislocation secondary to immobilization 4-5-week-old white rabbits Freeman and England [12] Hip dislocation and ligamentum teres rupture and coagulation and SS wire cerclage 8-10-week-old puppies Rowe et al [16] Ligamentum teres resection, ligating the femoral neck, immobilizing the knee joint 4-5-week-old rabbits…”

Intraosseous injection of mesenchymal stem cells for the treatment of osteonecrosis of the immature femoral head and prevention of head deformity: A study in a pig model

“…Nevertheless, newly formed bone is fragile, which means that weight bearing may flatten and/or deform the FH possibly leading to articular cartilage damage. [13][14][15] Thus, unlike adult ONFH, LCPD occurs in immature bone that has a characteristic vascularization, a greater capacity for plastic deformity, a reversible evolution due to a phenomenon of tissue regeneration by penetration of MSCs and a regenerative process following ischaemic necrosis carried out by apposition of new layers of bone from the necrotic bone itself.…”

Padronização de modelo animal para o estudo da necrose isquêmica da cabeça femoral na doença de Legg-Calvé-Perthes

“…Também, propõem-se introduzir os testes de avaliação da marcha para análise funcional. [11][12][13][14][15][16][17][18] deformidade da CF é mais evidente a partir deste período de isquemia. 11 Operaram-se onze leitões, híbridos comerciais (cruzamento das raças Large White e Landrace), machos, pesando entre 4 e 6 kg, idade de 3 a 4 semanas.…”

“…Also, we proposed to introduce gait evaluation tests for functional analysis. 11 12 13 14 15 16 17 18 …”