Summary
Objectives: To describe a novel humeral fixation device, the insertion technique, healing of
humeral osteotomies, and clinical outcomes in a caprine model over a six month period.
Methods: Fourteen mature female Boer/Nubian cross goats with a mean body weight of 50.7 kg
were implanted with a proprietary segmented interlocking nail (SILN) in both humeri.
Each goat had one humerus randomly selected for mid-diaphyseal osteotomy.
Results: Immediately after surgery all but one goat was able to stand, although none of the
goats were weight bearing on the osteotomy limb. During the six month study, clinical
lameness was always associated with the osteotomy limb. One month after surgery, lameness
for twelve of the goats was grade 2/5 or better. At three months, 11 of the 14 did
not exhibit any signs of lameness. On radio-graphic images, notable malalignment of
the osteotomy was observed, although all osteotomies went to bone union.
Clinical significance: The results of this study suggest that despite misalignment, the SILN maintained
adequate osteotomy fixation to achieve bone union in the research model studied, with
reduced morbidity and early return to function with bilateral implantation. The SILN
used in this study allowed intramedullary fixation of humeral diaphyseal osteotomies
with a limited and safe surgical approach.
Keywords
Segmented - humerus - interlocking nail - osteotomy