Medical therapy is frequently disappointing for horses with PSD. Typically
a 3-month period of rest and handwalking will be combined with 3
application of extra-corporeal shock wave therapy. Intra-lesional injections
with stem cells, IRAP, platelet-rich plasma (PRP), pigs’ urinary bladder
matrix (A-Cell) have also been used, as have peri-ligamentous injections
of corticosteroids and sarapin. Shoeing with a wide web in the toe region
and narrow branches has become popular in Europe, while elsewhere egg
bar shoes are still used. Overall, more than 50% of horses tend to stay
lame with medical treatment. Surgical treatment consists of neurectomy of
the deep branch of the lateral plantar nerve with or without a fasciotomy of
the deep lamina of the retinaculum flexorum of the distal tarsus. Results
are good, but some horses suffer further exacerbation of suspensory
desmitis with recurrence of lameness.
Concurrent medication of the tarsometatarsal joint and/or the sacroiliac
joints may be useful in some horses for complete resolution of lameness.
The presence of a straight hock conformation or hyperextension of the
hind fetlock is a poor prognostic indicator.
It has been suggested that dressage horses tolerate hindlimb PSD less
well than show jumpers or event horses, probably because the
temperament of the horses is different and the enjoyment of jumping can
override low-grade pain. For dressage horses, modification of the training
program is often required, particularly in terms of avoiding a fatiguing
training session in deep or loose surfaces. Medium and extended paces
should be avoided as far as possible during training. Young dressage
prospects may need a 3-month period of rest after purchase and then a
very gradual introduction into their work program to try to prevent PSD
from becoming clinically apparent.
Suspensory branch desmitis
Diagnosis is made by clinical examination in most horses and confirmed
by ultrasonography. In some horses, diagnostic anesthesia is necessary to
localize lameness and fiber disruption will only be detected on
ultrasonographic screening of an otherwise relatively unremarkable
branch. The PSBs may or may not show radiological evidence of
enthesopathy, with parallel linear opacities extending from the palmar or
abaxial margin. Treatment is prolonged rest (4 to 6 months) with a slow
return to exercise. Intralesional injections using PRP have met with
promising results. Shock wave therapy (three treatments at 2-week
intervals) may also be useful by increasing a local tissue levels of growth
factors. Treatments are combined with a controlled walking exercise
program for 3 to 4 months. The presence of extensive periligamentous
fibrosis is a poor prognostic indicator. The risk of recurrence is high.
Distal tarsal osteoarthritis
Lameness or poor performance associated with pain arising from the distal
tarsal joints occurs
frequently in Sporthorses. Pain is often bilateral, and the presenting
problem is often shortening of the hindlimb stride and an inability to collect,
rather than overt lameness. Clinical signs mimicking back pain may be
15-‐18
February
2016
East
London
Convention
Centre,
East
London,
South
Africa
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