Kanjuro Otomo

Observations on the healing process of the medial patellar ligament after desmotomy in cattle.

Macroscopic and microscopic observations were made on the healing process of cut ends in the medial patellar ligaments during a period from 7 to 201 days after desmotomy in 24 normal cattle. Lameness was not seen in any of the cattle after the operation. Adherence at the severed site was not observed in any of the samples. The connective tissue already had bound up the cut ends 7 days after the operation. The repair tissue was grossly distinguishable from the ligament and surrounding connective tissue in all samples. On the basis of gross observations, the authors divided the repair period into three stages. In the early stage, there was no significant increase in the distance between the ends of the cut ligament since the operation, in the intermediate stage the distance tended to increase, and in the last stage the distance decreased. The mean distances observed in each of the stages were 19mm±S. D. (range 17 to 23mm), 23mm±S. D. (range 13 to 33mm) and 14mm±S. D. (range 7 to 27mm), respectively. Microscopic observations, demonstrated loose connective tissues in the gap during the early stage were loose connective tissues. Thereafter, fibroblasts closely aligned in longitudinal direction in the area closest to the cut ends. This arrangement progressed gradually towards the center of the gap. In the sample taken 201 days after operation, however, the cell density in the gap was identical to that of the ligament tissue. These results suggested that connective tissues in the gap gradually changed to ligament tissues.