Osteophyte formation in experimental bipedal rats

The occurrence of osteophytes in the spines of experimental permanent bipedal rats was studied and the results were compared with the osteophytes of normal quadrupedal rats. the curves of distribution of the osteophytes were similar in both groups, but the bipedal rats showed much higher frequencies of osteophytes. Osteophytic frequency increased with age and more osteophytes were present in male than in female bipedal rats. The higher pressure imposed on the vertebrae by the erect posture probably explained the greater development of osteophytes in the bipedal groups. The results of the present study seem to give further support to the conception that osteophytes develop as a consequence of pressure exerted on the spine and as a protective mechanism.