1. Department of Trauma and Orthopaedic Surgery, Royal College of Surgeons in Ireland, Cappagh National Orthopaedic Hospital, Finglas, Dublin 11, Ireland
2. Department of Orthopaedic Surgery, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
3. Department of Orthopaedic & Spinal Surgery, Mater Private Hospital, Eccles Street, Dublin 7, Ireland