TDK conference 2020

Osteochondrosis (OC) is a common orthopedic disease affecting the skeletal system of young horses. Recent research has proven that osteochondral lesions develop as a result of a disorder in enchondral ossification processes. Therefore, these lesions are formed before the horse reaches skeletal maturity. One of the most frequent manifestations of OC is osteochondral articular fragmentation (osteochondrosis dissecans, OCD) in the metacarpo(metatarso)phalangeal, tarsocrural and femoropatellar joints. Diagnostics of OCD lesions with radiological examination and arthroscopic fragment removal are routinely performed therapeutic actions in the surgical treatment of this disease. Despite the large number of OCD-related arthroscopic surgeries, there is no adequate clinical data about secondary cartilage lesions discovered during fragment removal. The effect these additional cartilage injuries may have on the physical condition (joint effusion, lameness) and the sports career of the horses is also a scarcely investigated issue.

In our study, we analyzed arthroscopic videos of 22 fetlock joints of 16 horses that underwent arthroscopic fragment removal at the Department and Clinic of Equine Medicine. We evaluated the type, exact location and severity of the secondary lesions using a scoring system defined by the International Cartilage Repair Society (ICRS score). These data on the secondary articular surface lesions were compared to the findings of the preoperative lameness and radiological examinations.

The results were interpreted in two age groups. 20 of 22 joints showed secondary cartilage injuries on the articular surfaces. The most common types of lesions were wear lines and erosions. They were located on the side of the osteochondral fragment more often than in other areas of the articular surface. The severity (ICRS score) of the described lesions was significantly higher in the older age group. Joint effusion was present in nine fetlock joints with a minimum lesion severity of ICRS 2. Lameness was diagnosed in five limbs where a minimum lesion severity of ICRS 3 was shown in the arthroscopic visualization of the fetlock joints.

Based on our results, it can be concluded that osteochondral fragments of the metacarpo(metatarso)phalangeal joints may cause mild to severe secondary cartilage lesions, which can affect the sports career of the horses. Therefore, to avoid further cartilage injuries, the arthroscopic removal of these fragments is the recommended way of treatment in these cases.