I was recently on-farm for a routine visit, when the farmer mentioned that he had an odd lame cow that hadn’t yet responded to any treatment.

When we looked at her, she was dramatically lame, with a back leg that swung to the side wildly as she walked. The lameness seemed so serious, it nearly caused the farmer to euthanise her rather than getting a veterinary exam – but luckily I was already coming out to the farm for another job.

On physical examination, I found that the kneecap was locked over the medial trochlear ridge of the femur and held in place by the medial patellar ligament. This was causing the leg to be locked into rigid extension.

Fortunately for this cow (and a relief for the farmer), there is a relatively straightforward surgery to relieve this situation, called a medial patellar desmotomy.

After sterilising the area and applying local anesthetic, I used a scalpel to cut a small incision through the skin to access the stifle joint. The offending medial patellar ligament was located and snipped with the scalpel.

With just these two small cuts, the cow walked away like nothing had ever been wrong!

Although this condition is somewhat common in Brahman breeds of cattle, it is quite rare to come across in this part of the world, making it an interesting and satisfying case to see and fix.