Author/Editor		Antolič, V; Kralj-Iglič, V; Iglič, A; Srakar, F
Title		Legg-Calve-Perthes' disease: stress distribution in the hip joint articular surface after varisation osteotomy
Type		članek
Source		In: Held KD, Brebbia CA, Ciskowski RD, Power H, eds. Computational biomedicine. Southampton: Computational mechanics publications,
Publication year		1993
Volume		str. 255-62
Language		eng
Abstract		Biomechanical influences of the varisation osteotomy performed on 7 clinical cases of Legg-Calve-Perthes' disease with lateral subluxat!on of the tlattened femoral epiphysis are studied. For this purpose, a three dimensional mathematical model of the hip joint articular surface is used, taking into account the spherical shape of the femoral head and of the acetabulum inner surface before and after the operation. The model assumes that stress on the hip joint anicular surface is proponional to the cosine of the angle between the pole of the stress distribution and any point on the articular surface sphere. The average varisation in our series was 20 degrees, and the maximal stress decreased for about 20 per cent . In all the cases a significant improvement in the sphericity of the femoral head epiphysis was observed one year after the operation, presumably because the lateralized part of the epiphysis is placed under the acetabular roof after varisation osteotomy. Plastic remodelling of the femoral head is thus enhanced. Acetabulum was slightly dysplastic before the operation and did not change after varisation.
Descriptors		LEGG-PERTHES DISEASE OSTEOTOMY HIP JOINT BIOMECHANICS MODELS, THEORETICAL