often no obvious joint effusion. Anesthesia of the lateral plantar metatarsal
nerve at the distal end of the lateral splint bone eliminates pain in the
lateral condyle of the distal third metatarsal bone. MR imaging shows a
gamut of intra-osseous changes ranging from localized bone oedema,
over bone densification, to bone densification with a small center of
osteonecrosis and finally a pathological depression fracture or full
thickness erosion through the overlying articular cartilage. While the
plantar aspect of the lateral condyle of MTIII is more commonly affected in
racehorses, the dorsal aspect of the medial condyle and the sagittal ridge
of MTIII as well as the sagittal groove of P1 are predilection sites in
Sporthorses. Treatment consists of rest with handwalking for a minimum of
3 months. IRAP can be used intra-articularly as a chondroprotective agent
to prevent progression to OA in the joint. Some clinicians like to use
tiludronate by infusion to suppress bone inflammation in horses with bone
oedema.
Arthroscopic debridement of damaged cartilage and focal bone erosions
on the dorsal aspect of the metatarsal condyles may be curative.
Excessive erosion of the articular cartilage warrants a poor prognosis for
continued jumping.
Stifle pain (Jumpers)
Problems involving the stifle joint are common in show jumpers. Joint
effusion is present variably. Signs may be subtle at first, with mild
shortening of the stride or switching leads at the canter or gallop.
Separation of stifle and tarsal pain may be accomplished by flexing the
stifle with the hock slightly extended so that the metatarsal region is held
behind the tail and perpendicular to the ground, with the tibia held parallel
to the ground. Abducting and adducting the lower limb in an attempt to
stress the stifle may also be useful. Even so, intraarticular analgesia is
always required to confirm the stifle as the source of pain.
Sporthorses often undergo various treatments of the medial patellar
ligament in order to improve their gate. A tentative diagnosis of mild
intermittent upward fixation of the patella is made to justify the treatment.
Soft tissue injuries to the stifle are relatively common in Sporthorses.
The cranial cruciate ligament is relatively rarely affected. Intraarticular
analgesia of the femorotibial joints may or may not abolish the lameness,
and routine imaging may be normal in horses with an acute injury. With
chronic injury, entheseous remodeling of the insertion of origin of the
ligament may become visible on radiographs.
Meniscal injuries are much more common and the medial meniscus is
more frequently affected. Intraarticular analgesia of the femorotibial joint
on the affected side usually produces improvement in the lameness.
Radiographic evidence of new bone formation on the dorsal margin of th e
medial intercondylar eminence on flexed lateromedial views is
pathognomonic for meniscal injury. Later on, osteophytes develop on the
proximomedial aspect of the tibial plateau indicative of OA.
Ultrasonographic examination may show disruption of the normal profile of
the meniscus if tearing extends into the lateral or medial middle third of the
meniscus, adjacent to the collateral ligaments. The cranial part of the
15-‐18
February
2016
East
London
Convention
Centre,
East
London,
South
Africa
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