Undisplaced femoral neck fractures--no problems? A consecutive study of 224 patients treated with internal fixation

224 patients with undisplaced femoral neck fractures treated with two parallel Hansson hook pins were studied. After a mean follow-up time of 32 months (S.D. 5.2), 15% had a reoperation. 11% were considered failures, mostly avascular necrosis, and 9% had a secondary arthroplasty. Possible risk factors for poor outcome were analysed. Neither high age nor surgical delay was associated with increased failure rate. Survivors received a questionnaire, and 40% stated that they had mild or severe pain in the hip when walking, 25% had pain at rest and 25 stated that they thought "always" or "often" about their injury. The younger the patient, the more frequent the report of subjective pain. 51% of individuals under 80 years reported pain when walking, compared to 27% aged 80 or older (p=0.016). Corresponding numbers for pain at rest were 32 and 12% (p=0.034). The failure rate did not differ between the age groups, but the younger patients had more reoperations (p=0.046) and thought more frequently about their injury (p=0.016). An undisplaced femoral neck fracture is a major injury with a long-term daily discomfort in about 25% and clinical failure in 11%.