The intercarpal ligaments of the equine midcarpal joint, Part 3: Clinical observations in 32 racing horses with midcarpal joint disease.

The study explores clinical features of intercarpal ligament pathology in horses, emphasizing the relationship between varied types of ligament damage and other intraarticular injuries. Notably, the researchers uncover that severe bone damage and specific ligament injuries rarely occur in the same joint, with no clinical or radiographic observations able to precisely identify intercarpal ligament injuries from other carpal injuries.

Scope and Methodology

• The research involves a prospective clinical observation of 32 racing horses, consisting of 28 thoroughbreds and 4 standardbreds.
• The study assessed 53 midcarpal joints in these horses through clinical, radiographic, and arthroscopic examinations.

Findings: Ligament Tearing

• The researchers identified palmar intercarpal ligament tearing as prevalent in 30 joints of 22 horses.
• Likewise, some rupturing of the medial palmar intercarpal ligament (MPICL) was present in 27 joints of 20 horses, while tearing of the lateral palmar intercarpal ligament was noticed in 9 joints of 7 horses.
• The researchers found no correlation between the severity of clinical signs recorded and the degree of MPICL tearing.

Findings: Cartilage and Bone Damage

• The study found that joints with grade 2-4 MPICL tearing had significantly less cartilage and bone damage than those with grade 1 or no ligament damage.
• An inverse relationship was established between the number and size of intra-articular fractures and ligament damage, as assessed radiographically.

Findings: Dorsomedial Intercarpal Ligament Hypertrophy and MPICL Damage

• The dorsomedial intercarpal ligament (DMICL) was identified in all joints, and it was enlarged in 18 joints.
• There was a significant correlation between MPICL damage and hypertrophy of the DMICL, however, the same correlation was not observed between DMICL hypertrophy and either articular cartilage damage or subchondral bone damage.

Conclusions

• The study concluded that severe subchondral bone and MPICL damage rarely occur in the same joint.
• Moreover, the researchers hypothesize that DMICL hypertrophy may be associated with joint disease rather than being a causative factor.
• This points to the fact that there are no clinical or radiographic findings that can differentiate intercarpal ligament injury from other carpal injuries, and diagnosis is only possible via arthroscopic examination of the midcarpal joint.