Late onset imminent femoral fatigue fracture associated with intraoperative cement extrusion as a rare cause of thigh pain after total hip replacement.

Abstract

Cement extrusions on the femoral side after total hip replacement can occur in approximately 0.3% of cemented primary total hip replacements. Not recognised until a postoperative x-ray is performed, the willingness to dismiss and treat these extrusions conservatively is high. We report on 3 patients presenting with sudden onset of thigh pain associated with an inability to weight-bear after a 2 to 15 month period of uneventful healthy recovery from cemented total hip replacement. On immediate postoperative x-rays occult cement extrusion in the posterolateral circumference of the femoral component tip were present. X-rays and CT scans showed no fracture signs. Scintigraphy revealed late increased uptake at the extrusion height. With the hypothesis of imminent femoral fatigue fracture, all patients underwent revision surgery. The defect sites were surgically exposed, thoroughly cleaned of cement, filled with iliac crest bone graft and stabilised with tension band plating. This procedure resulted in fully recovered asymptomatic patients at 6 weeks and after a mean follow-up period of 48 months, as demonstrated by their pain level and tolerance of full weight bearing. These cases lead us to adopt a low threshold for immediate revision when occult cement extrusion is recognised near the tip of a cemented stem on postoperative films, and to adopt a low threshold for surgical revision when, in the presence of cement extrusion, thigh pain is a complaint. We favour tension band plating and bone grafting over more complex implant revisions since a fast recovery was achieved in these patients.