Introduction: It was noted that INR levels transiently increased before dropping after stopping warfarin pre-operatively in warfarinised patients with femoral neck fractures. Surgery was more likely to be delayed in these patients. The aim of this retrospective study was to determine the trend of INR level after stopping warfarin and to determine the morbidity and mortality in these patients.

Material and Methods: All patients with femoral neck fracture who were on warfarin between 01.01.2002 and 31.12.2003 were included. Case notes and haematology reports were reviewed.

Results: 22 (4.2%) out of 533 patients with femoral neck fractures were found to be on warfarin on admission. 21 case notes were obtained. 7 male and 14 females with mean age of 81 years. In 11 (52%) cases, INR level increased before coming down after stopping warfarin. 60% of them had morphine as analgesic compared to 40% in the other group. Average rise in INR was 0.4. Average delay in surgery due to high INR was 3.5 (range 1–8) days. It took average of 4 days to achieve desirable INR after restarting warfarin. 6 (28%) needed blood transfusion. Nine (43%) patients developed complications including: intra-operative bleeding-1, postoperative DVT-1, fast AF-2, post-operative anaemia-1, other medical-3. One patient (5%) died from large CVA 12 days after surgery. No further mortality was found within 30 days of surgery.

Conclusion: Incidence of femoral neck fractures on warfarin was 4.2%. In over half of the cases, the INR level went up before going down after stopping warfarin. Morphine may be responsible for this trend. Delay in surgery does not seem to increase mortality or morbidity compared to published studies.