[Decreased acetabular anteversion and femur neck antetorsion cause pain and arthrosis. 1: Statistics and clinical sequelae].

PROBLEM

This paper investigates which angles of acetabular (AA) and femoral antversion (FA) have to be considered as normal and which ones cause changes in range of movements, pain and osteoarthrosis. METHOD OF INVESTIGATION: 15-20 degrees of anteversion of AA and FA were tested regarding normality. Diminished anteversion angles were divided in groups -2 and -3, and increased angles in groups +2 and +3.

RESULTS

The material consisted of 356 hip joints with computerized tomographies, investigated separately in different deformities. Changes in range of movement, pain and osteoarthrosis were minimal in the normal angle group 1 and increasing in the extreme angle groups -2 and -3 and +2 and +3. Diminished AA and FA cause a decrease of internal rotation of the hip and an increase of external rotation, pain and osteoarthrosis. When groups of diminished AA or FA angles were found combined with the normal angle group 1 or increased angles of AA or FA (+2/+3), the pathological consequences were compensated or diminished especially by higher FA angles and less by AA angles. The results in all investigations were statistically significant if the number of observations was large enough. The instability index of McKibbin was used in the different angle groups of deviation from normal. Adding the angles of AA and FA together gives a good impression of the degree of instability or rigidity and the prognosis of the joint.

SIGNIFICANCE

In children and adults diminished AA and FA are quite frequent. They cause pain and osteoarthrosis, but are diagnosed seldom.