Stability of femoral neck fractures: A postoperative roentgen stereophotogrammetric analysis

Abstract

Using roentgen stereophotogrammetric analysis, the postoperative stability of femoral neck fractures was measured in 16 patients. During the first day after internal fixation, before weight bearing, the center of the femoral head moved on an average 1.5 mm (total translation) in six undisplaced fractures and 3.7 mm in 10 displaced fractures, which was about one third of the fracture movement during the first postoperative month. Three undisplaced fractures displayed a rotatory instability, mainly after weight bearing had begun. Five of the displaced fractures showed maximal rotatory displacement during the first postoperative day. The recorded fracture movements before weight bearing may question the rationale of peroperative mechanical compression.