Stress reactions and stress fractures of the proximal palmar aspect of the third metacarpal bone in horses: 58 cases (1980-1990).

The research investigates 58 cases of horses that suffered from stress reactions or stress fractures in a specific part of the bone. Following treatment which typically involved rest, over 60 percent were able to return to their previous level of performance.

Study Sample and Methodology

• The study was carried out by reviewing case records, radiographs, and nuclear bone scans of 58 horses, of different breeds, that demonstrated stress reactions or fractures.
• The majority of the horses were racehorses or performance horses, and the mean and median ages of these horses were 4 and 3 years, respectively.
• The assessment of lameness, physical findings- including signs of pain on deep touch and mild swelling of the middle carpal joint in some instances, were part of the review process.
• Additionally, the researchers found that lameness was noticeably improved following high palmar and palmar metacarpal nerve blocks or anesthesia of the middle carpal joint.

Key Findings

• Of the 58 horses studied, 53 presented a higher than usual uptake of radiopharmaceuticals (used in bone scans to highlight areas of the bone where there may be a number of conditions) in the affected part of the bone.
• This abnormal uptake was in either the left or right limb. The remaining 5 horses showed this abnormal uptake in both limbs.
• Fifty-six of the 63 limbs with unusual bone scans also had abnormal radiographs, reinforcing the presence of stress reactions or fractures.

Treatment and Outcome

• The researchers implemented a treatment process consisting of a variable rest period, ranging from 1 to 6 months depending on the severity of the condition.
• The effectiveness of this treatment was best evaluated through follow-up bone scans.
• In terms of treatment outcomes, of the 45 horses for which there was sufficient follow-up information, 29, which equates to 64%, were able to return to their usual level of performance.