THE REDUCTION OF HUMERAL FRACTURE IN PIGEONS WITH INTRAMEDULLARY POLY(METHYL METHACRYLATE) AND NEUTRALIZATION PLATE FIXATION

The reduction of experimental humeral fracture in pigeons was performe d with intramedullary bone cement (poly (methyl methacrylate): PMMA) a nd neutralization plate fixation to investigate the effect on bone fra cture healing and the recovery of flying ability. As a result, neither plate nor bone cement fixation held for more than 2 weeks, but no ref racture was observed in any cases with both plate and bone cement. In the latter group, it was confirmed by flight tests that almost normal flying ability was recovered in 6 weeks. In pathological findings, blo od supply to the fractured ends recovered within 2 weeks and no cortic al bone necrosis was observed at the time except for a disturbance of endosteal callus formation. The process of fracture healing on the pla te side took place slightly later than that on the non-plate side, and when much PMMA remained between the fractured ends of the cortical bo ne the bone formation became spongioid. In view of the quick recovery of flying ability, however, plate and bone cement fixation is consider ed appropriate to prevent the displacement of a humeral fracture in th e pigeon.