Towards painless orthopaedic surgery.

Almost one thousand patients underwent either total hip replacement or spinal surgery in which diamorphine 0.5-1.0 mg was injected intrathecally. Approximately one half of the arthroplasty patients and one third of the spinal patients required no other post-operative analgesia. In the remainder, analgesics were not required for 12 hours post-operatively. The benefits of the technique and possible complications are discussed.