Disaster Victim Identification using Orthopedic Implants in the 2011 East-Japan Earthquake and Tsunami.

On March 11, 2011, an earthquake (magnitude 9.0) devastated Japan's east coast, and the associated tsunami resulted in social and mechanical destruction. Search for the missing people is still ongoing. Surgical implants are common in the general population. Medical implants usually have lot numbers, and their forensic use is common for victim identification. This investigation was conducted mainly in the cities of Kamaishi and Otsuchi, both of which were affected by the tsunami disaster in 2011. We visited 6 mortuaries with the police between March 20 (9 days after the tsunami) and April 20 (40 days after the tsunami) to examine the presence of surgical scars and related information. Unidentified human remains were investigated by visual and tactile examination. We also visited temples where the ashes were preserved. If implants were found, their lot numbers and estimated surgical procedures were recorded to determine positive identification. Ten of 233 sets of unidentified human remains before cremation displayed characteristics of a potential past surgical history. However, only 2 of these 233 sets had orthopedic implants. Instead, non-combustible orthopedic implants were found and recognized in 8 of the 331 sets of unidentified human ashes in the temples after cremation; the lot numbers were fully legible in 2 of the 8 sets. We estimated the surgical procedures, which led to positive identification. In conclusion, lot numbers and the surgical knowledge of orthopedic surgeons could assist with the positive identification of disaster victims. However, the relevant information can be erased after cremation.