Production of patellar lesions by medial patellar desmotomy in normal horses.

The research study is about investigating the effects of a surgical procedure called medial patellar desmotomy on the knees of horses and finding out that it leads to pathological knee changes, suggesting its use only in specific confirmed cases.

Study Design and Procedure

• The research was executed on 12 healthy horses. Medial patellar desmotomy, a surgical procedure performed to alleviate a condition in horses known as “upward fixation of the patella”, was performed on one hindlimb (treated) of each horse.
• A sham operation, presumably for control purposes, was performed on each horse’s other hindlimb (control).
• The horses were examined for lameness before the operation and at specific intervals afterwards: at the 1st, 2nd, and 3rd months.
• At the end of three months, the researchers examined the femoropatellar joints (knee joints) both radiographically (using X-rays) and arthroscopically (with an arthroscope) for any changes.

Findings

• All horses showed lameness (difficulty moving due to discomfort or pain) in the limb that had undergone medial patellar desmotomy at 1, 2, or 3 months.
• Radiographic examination showed changes in 11 of the 12 horses’ knees, such as fragment formation at the bottom of the patella (knee cap) and bone production where the middle patellar ligament attaches to the patella.
• Arthroscopic examination also revealed damage to the articular (joint) cartilage on the patella of all treated limbs. In six of the horses, fragments of bone and cartilage that were loosely attached had to be arthroscopically removed from the lower part of the patella of the treated limb.
• In contrast, the control limbs of the horses (which had undergone a sham operation) were found to be normal throughout the study, both clinically and upon radiographic and arthroscopic examination.

Conclusion

• The study concludes that medial patellar desmotomy causes pathological changes in patella’s articular cartilage and adjacent soft tissues.
• Therefore, the researchers suggest that this surgical procedure should only be used for persistent cases of upward fixation of the patella that have been confirmed through diagnosis.