Osteitis of the axial border of the proximal sesamoid bones in horses: eight cases (1993-1999).

The research article explores the cause, effects, and possible treatments for osteitis (inflammation of a bone) at the border of the proximal sesamoid bones in horses. It is found that both infection and non-infectious inflammation of the bones can lead to this condition and the subsequent chronic lameness. Possible treatments including arthroscopic debridement have been tested, some of which proved effective particularly for horses not affected by disease or infection.

Methodology

• The study was retrospective, meaning data was collected and analyzed after events had taken place.
• Eight horses were included in the study. Data was collected from these animals’ medical records for analysis.
• Data of particular interest included each horse’s basic details such as age and breed (signalment); their past medical history; their use (for instance whether they were racing or working horses); the severity and duration of their lameness; results from various diagnostic tests including perineural anesthesia, radiography, ultrasonography and scintigraphy; and their outcomes following surgery.

Results

• Three out of eight horses revealed sepsis in either the metacarpophalangeal or metatarsophalangeal joint, or the digital synovial sheath. The other five showed no signs of disease or infection.
• Every horse in the study had experienced chronic, or long-term, unilateral lameness.
• Anesthetic was applied to each of the affected joints. In three out of five horses, this led to an improvement in symptoms. The other two horses only improved after anesthetic was administered to the digital synovial sheath.
• Nuclear scintigraphy, a type of imaging test, was used successfully to pinpoint the source of lameness to the proximal sesamoid bones in four of the horses.
• Arthroscopy, a surgical procedure that allows doctors to view joints, revealed damage to the ‘intersesamoidean’ ligament, as well as osteomalacia (softening of the bones) on the edge of the proximal sesamoid bones in all horses.
• All five horses not affected by sepsis, plus one septic horse, returned to their prior uses following their surgeries.

Conclusions

• The study’s results indicate that osteitis along the axial border of the proximal sesamoid bones is a unique issue that typically crops up in connection with inflammation of the associated metacarpointersesamoidean or metatarsointersesamoidean ligament.
• This inflammation may stem from either septic or nonseptic conditions.
• The researchers found evidence to suggest that arthroscopic debridement, or surgical removal of damaged tissue, could prove beneficial in allowing horses without sepsis to return to their prior levels of performance.