Page 224 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.5 The hindlimb 199

VetBooks.ir discomfort appears to prevent an increase in muscle 1.381
mass and in these cases medium-term treatment with
oral NSAIDs, possibly combined with intra-articular
medication of the femoropatellar joint with a corti-
costeroid preparation, can be useful. Many young
animals ‘grow out’ of the condition. The failure of
conservative management, or severe clinical signs on
presentation, warrants surgical intervention in the
form of either medial patellar ligament desmotomy or
splitting of the medial patellar ligament. Medial patel-
lar ligament desmotomy is most easily performed in
the standing horse under sedation and local anaesthe-
sia (Fig. 1.381) so that the ligament is under tension. Fig. 1.381 Desmotomy of the medial patellar
Postoperatively, it is recommended to rest the horse ligament in a standing sedated miniature pony with
in a box for 2 months, providing gentle walking in upward fixation of the patella.
hand during the second month. After surgery, in the
absence of degenerative changes in the joint, horses returned to work too quickly (Fig. 1.382). Splitting
are expected to return to normal use, although some the medial patellar ligament percutaneously under
may develop a slightly restricted gait. Some cases have ultrasonographic guidance, most often under general
been reported to develop distal patellar fragmentation anaesthesia, is as effective as desmotomy and without
and severe lameness after surgery, especially if they are any serious complications (Fig. 1.383). Medial patellar
ligament splitting also appears less likely to lead to a
restricted gait in the longer term than a desmotomy.
1.382 Other clinicians, particularly in parts of Europe and
North America, use counterirritant agents injected
into the patellar ligaments as an alternative technique,
although with little scientific evidence of its effective-
ness. The medial patellar ligament lies very close to the

1.383

Fig. 1.382 Magnified lateral view radiograph of Fig. 1.383 Intraoperative view of ultrasound-guided
the distal patella of a horse that developed distal medial patellar ligament desmectomy carried out under
patellar fragmentation (arrow) post medial patellar general anaesthesia. (Photo courtesy Graham Munroe)
desmotomy. (Photo courtesy Graham Munroe)