Surgical treatment of subchondral cystic lesions of the third metacarpal bone: results in 15 horses (1986-1994).

The research examined the surgical outcomes of 15 horses treated for cystic lesions in the third metacarpal bone. The results indicated that approximately 80% of the horses regained their intended use post-surgery, suggesting this method of treatment can yield a positive outcome for athletic roles.

Objective of the Study

• The research aimed to study the effects and outcomes of surgical treatment for subchondral cystic lesions (SCLs) in the third metacarpal bone (MCIII) of 15 horses.

Patient Demographics

• The median age of horses treated was 18 months, with a range of 10 months to 12 years. Ten of the fifteen horses were younger than two years of age.
• All observed SCLs were found in the front limbs of the horses, with two cases presenting bilateral lesions.
• One case had an additional cystic lesion in the right medial femoral condyle.

Medical History and Clinical Presentation

• Fourteen out of the fifteen horses exhibited a history of moderate lameness linked to the metacarpophalangeal joint. The lesion was incidentally discovered in one horse.
• The duration of lameness varied, with onset periods ranging from four weeks to eight months. In all cases, lameness was exacerbated by fetlock flexion.
• Whilst synovial effusion is often linked to such lesions, it was absent in 53% of the cases in this investigation.

Surgical Methods and Outcomes

• Surgical curettage of the cystic lesions was the common treatment procedure, implemented arthroscopically in twelve horses and through dorsal pouch arthrotomy in three horses.
• Concurrent osteostixis was performed in seven horses.
• Two horses needed arthroscopic treatment for osteochondral fragmentation a year post the initial surgical treatment.
• Twelve of fifteen horses, or 80% of the sample, regained soundness for their intended use after surgery.
• However, two horses did not recover completely and no follow-up data was available for one horse.

Follow-Up Examination

• Follow-up ranged from one to six years.
• Of the nine horses for whom follow-up radiographic examinations were conducted, five showed mild periarticular osteophyte and enthesiophyte formations at the dorsal joint capsular attachments.
• Bony ingrowth of the cystic lesion was observed in eight horses and enlargement of the cystic cavity in one.

Study Findings

• The research concluded that surgical treatment of SCLs in the distal metacarpus can result in a favourable outcome for athletic use, based on the high percentage of horses regaining soundness post-surgery.