How often do elderly patients develop knee fluid after surgery for a hip-area fracture, and how long does it last?

Details

This observational study examined knee effusion—fluid buildup in the knee—in 155 consecutive elderly patients who underwent surgery for a proximal femoral fracture, a fracture of the upper part of the thigh bone. It compared preoperative and postoperative findings.

Before surgery, effusion was present in 7.7% of knees on the same side as the fracture and 1.3% of knees on the opposite side. After surgery, 50 patients (32.3%) had an effusion in the knee on the fracture side. In seven of these patients, the effusion had already been present before the operation. All of the effusions resolved completely within three weeks after surgery.

Laboratory analysis of samples of the accumulated fluid from eight randomly chosen patients showed non-inflammatory fluid. The authors suggested that the effusions were probably traumatic in origin and likely a response to stresses experienced during the operation or at the time of the fracture; this explanation was not presented as established.