A second Prince of Wales Orthopaedic Hospital (the first was opened in 1918 in Cardiff (nprn 406994) was built by the Canadians at the beginning of the Second World War near Rhydlafr Farm. The 81st US General Hospital was established at Rhydlafar in mid-1943. It employed American and British nurses and dealt with casualties from the Battle of Normandy. The camp was composed largely of Nissen type hutments. From 1946 it was converted by the Ministry of Works to the Prince of Wales Orthopaedic Hospital and opened in 1953 at cost of £500,000.
In August, 1945, the Welsh Board of Health, recognising the priority of need to create an adequate orthopaedic service, invited the Prince of Wales Orthopaedic Hospital Committee to take over the ex-American Army Hospital at Rhyd Lafar. The scheme was submitted to the Ministry of Works on 24th July, 1946. The building replaced the American hospital which was composed of Nissen type hutments.