Osteochondral fragmentation of the plantar/palmar proximal aspect of the proximal phalanx in racing horses.

This research evaluates the clinical presentation and treatment outcomes of osteochondral fragmentation affecting the plantar/palmar proximal aspect of the proximal phalanx in racing horses. The primary findings suggest that this condition is a common reason for decreased performance and mild lameness in racing horses. Arthroscopic removal of fragmented elements tends to offer significant improvement in race performance for the majority of cases.

Introduction

• The research features 26 instances of osteochondral fragmentation of the plantar/palmar aspect of the proximal phalanx in racing horses, where 23 were Standardbreds and three were Thoroughbreds. The most reported presentation reason was the inability to run straight at high speed.
• Only eight out of the 26 horses initially presented for lameness, while 19 were discovered to be lame upon further evaluation.

Presentation of the Condition

• The research indicates that 90% of the affected fetlock joints exhibited a positive flexion test, with 48% revealed joint effusion.
• It was demonstrated that the osteochondral fragmentation of the aforementioned region is a key reason for reduced-grade lameness in racing horses.

Treatment Approaches and Outcomes

• Out of the 26 horses, 23 had undergone arthroscopic fragment removal, and arthrotomy was implemented in one horse.
• Of the horses who returned to racing, which was a total of 16, 12 showed improvement in their race performance, while three showed no improvement, and one was retired due to different reasons.

Refragmentation and Degenerative Changes

• Refragmentation occurred in three horses after the surgery. However, two of those had shown race performance enhancement post the initial arthroscopic removal.
• Eight of the horses were discovered to have degenerative changes within the fetlock joint during surgery.

Conservative Treatment Approaches

• Four horses were treated conservatively. Of these, one showed temporary performance improvement after intra-articular medication, while one showed no improvement and two were resting.