Radiographic signs of ingrowth fixation
Moore et al CORR 2006
- 3 or more 97% stable
- 2 or less, 83% unstable
Five signs
- absence of radiolucent lines
- presence of a superolateral buttress
- medial bone stress-shielding
- radial trabeculae
- inferomedial buttress
Radiographic signs of loosening
5 signs
- radiolucent lines that appear after two years
- progression of radiolucent lines after two years
- radiolucent lines in all three zones
- radiolucent lines 2 mm or wider in any zone
- migration > 2mm
Engh Classification
I Osse-ointegration
A No RLL
B One RLL zone 1 or 2
C RLL zones 1 & 2
II Stable fibrous ingrowth
- <2mm zone 3
III Unstable fibrous ingrowth
- >2mm RLL in zone 3