- See: Impediments to Reduction
- Discussion:
- dislocated femoral head:
- femoral head and neck remain anteverted and in the valgus position;
- is pulled proximally & laterally by hip abductors;
- becomes misshapen & flattened;
- has delayed ossification of capital epiphysis;
- muscles crossing the hip jont (hamstring, hip adductors, & psoas) become shortened and contracted;
- psoas cross acetabulum, blocking reduction;
- arthrogram may show hour glass configuration of joint space;
- if hip remains dislocated (for weeks), limitation of abduction becomes a more consistent clinical finding;
- hip joint fills w/ fibrofatty debris known as pulvinar;
- acetabular labrum
- becomes enlarged along the superior, posterior, and inferior rim;
- may infold into joint (inverted limbus);
- limbus blocks reduction of femoral head;
- acetabulum
- becomes flattened (dysplastic) becuase it is not stimulated to develop around the absent femoral head;
- ligamentum teres becomes lengthened, hypertrophic & redundant;
- transverse acetabular ligament:
- is pulled superiorly w/ capsule which blocks lower portion of acetabulum;
- capsule of hip joint becomes expanded