Bone Healing Process of a Multiple Humeral Fracture in a Caretta caretta: Clinical, Surgical, Radiographic and Histomorphometric Assessments

Simple Summary Surgical treatment of sea turtle flipper fractures and the bones' subsequent repair process are not well documented in the scientific literature. This is the first case report describing the repair process of a multiple humeral flipper fracture in a sea turtle, after surgical stabilization, through periodic radiographic follow-up from 0 to 24 months. Due to the accidental death of the turtle 3 months after its release, it was possible to describe the progress of the fracture-healing process by histomorphometric analysis and to histologically compare the structure of the newly formed bone with the normal bone structure of these animals. Based on our findings in this case study, we may be able to obtain a better understanding of how repair tissue in marine turtles works, as well as helping with decisions regarding surgery. This study describes the surgical treatment of multiple humeral fractures in a Caretta caretta sea turtle referred by the 'Centro Faunistico del Parco Regionale Bosco e Paludi di Rauccio', in the area surrounding the city of Lecce, in southern Italy. Radiographs showed an evident detachment of the distal humeral epiphysis, compatible with a type II Salter-Harris fracture, as well as a transverse fracture of the diaphysis. After the surgical fracture reduction, radiographic follow-up was performed at 2, 4, 12, 16, and 24 months, showing a progressive healing and the formation of poorly mineralized callus tissue. Unfortunately, three months after his release at sea, the turtle was caught dead at a depth of 40 m. Histological and histomorphometric examinations of the surgically treated humerus were carried out on the corpse to collect further information about the bone tissue repair mechanisms in these animals.