In the presence of tendons lesser bony wear is seen at the acromion (acetabularisation, (p<
0.005), the glenoid (superomedial wear p=0.005) as well as the humeral head (femoralization, p=0.002). The radiological classifications according to Hamada and Favard seem not to be as appropriate to reflect accurately the location and extent of the tendino-muscular degeneration as the acromial acetabularization and humeral sphericity. The acromio-humeral distance is a good indicator for the location and the extend of the cuff tear arthropathy. A smaller acromio-humeral distance (95% CI: 4mm + 1) is only present if the postero-superior muscles are fatty degenerated (Goutallier stade III &
IV) and a larger distance is calculated (95% CI: 7mm + 3) when only the antero-superior muscles are diseased. The coracoid tip in cuff tear arthropathy-patients is almost always positioned in the inferior half of the glenoid (84%). A bigger supero-inferior distance of the glenoid in relation to the radius of the humeral head indicates more structural destruction of rotator cuff status (tendinous and muscular) and a worse clinical outcome.
We report an unusual complication of late dislocation of a total hip replacement. The femoral stem had completely migrated from the shaft. The insertion of a new long-stem prosthesis was successful.