 A Scottish population based study of 4062 patients identified at 3 months postop an incidence of 43% mild pain and 3% severe or very severe pain.The severe and very severe group was associated with young age and female gender.A further survey of the 3% severe pain cohort (at a median of 30 months) found that 29% resolved, 39% improved and 26% continued with severe, or very severe pain.