Influence of a novel scaffold composed of polyurethane, hydroxyapatite, and decellularized bone particles on the healing of fourth metacarpal defects in mares.

Abstract

ObjectiveTo determine the effect of a novel scaffold, designed for use in bone regeneration, on healing of splint bone segmental defects in mares.Study designIn vivo experimental study.Sample populationFive adult mares (4–10 years old; mean weight, 437.7 kg ± 29 kg).MethodsBilateral 2‐cm full‐thickness defects were created in the fourth metacarpal bones (MCIV) of each horse. Each defect was randomly assigned to either a novel scaffold treatment (n = 5) or an untreated control (n = 5). The scaffold was composed of polyurethane, hydroxyapatite, and decellularized bone particles. Bone healing was assessed for a period of 60 days by thermography, ultrasonography, radiography, and computed tomography (CT). Biopsies of each defect were performed 60 days after surgery for histological evaluation.ResultsOn the basis of radiographic analysis, scaffold‐treated defects had greater filling (67.42% ± 26.7%) compared with untreated defects (35.88% ± 32.7%; P = .006). After 60 days, CT revealed that the density of the defects treated with the scaffolds (807.80 ± 129.6 Hounsfield units [HU]) was greater than density of the untreated defects (464.80 ± 81.3 HU; P = .004). Evaluation of histology slides provided evidence of bone formation within an average of 9.43% ± 3.7% of the cross‐sectional area of scaffolds in contrast to unfilled defects in which connective tissue was predominant throughout the biopsy specimens.ConclusionThe novel scaffold was biocompatible and supported bone formation within the MCIV segmental defects.Clinical significanceThis novel scaffold offers an effective option for filling bone voids in horses when support of bone healing is indicated.