Abstract
Objective The main purpose of this study was to evaluate the characteristics of a vegetal polymeric
biomaterial intended for bone substitution in horses and to investigate the responses
of the equine third metacarpal bone to biomaterial implantation.
Materials and Methods Six horses were submitted to osteotomy on the dorsal aspect of the left and right
third metacarpal bones; one bone defect was randomly selected for treatment with biopolymer,
while the other was left untreated and served as a control. Bone density was monitored
radiographically after surgery and bone biopsy fragments were collected at the end
of the 120-day follow-up period. Biopsy fragments were analysed using light and scanning
electron microscopy.
Results Mean bone density values (mmAL) were greater in control defects (16.33 ± 1.6) than
in polymer-treated defects (14.17 ± 1.7) at 120 days (p = 0.027). Light microscopy revealed greater percentages of new bone formation in
control defects (50.15 ± 14.8) than in polymer treated defects (26.94 ± 12.1) at 120
days (p < 0.0001). Scanning electron microscopy analysis suggested a similar quality of pre-existing
bone and new bone formed in the presence of biomaterial.
Clinical Significance The absence of adverse reactions supports biomaterial biocompatibility and osteoconducting
capacity and suggests the castor oil polymer is a suitable bone substitute for the
treatment of bone defects in horses.
Keywords
horse - bone substitute - bone densitometry - castor oil polymer - microscopy
