Page 550 - Adams and Stashak's Lameness in Horses, 7th Edition

516 Chapter 4

VetBooks.ir

Figure 4.91. Lateral and dorsopalmar radiographs of the and was maintained in full work (reining) for 2 years after these
pastern with severe periarticular bone dorsally and medially but not radiographs were made. Recheck radiographs 2 years later were
joint space narrowing. Radiographs of the contralateral limb were largely unchanged and there continued to be minimal lameness.
nearly identical. This horse had minimal to no hindlimb lameness

Often oral NSAIDs are combined with IA medication more consistent results. Numerous surgical techniques
(steroid ± hyaluronan [HA]) of the PIP joint in horses have been proposed over the years to promote arthrode-
with chronic OA to reduce the signs of lameness and sis of the PIP joint. 6,8,21,23,28,31,37,41,59,66,67,74
improve the effectiveness of both treatments. A combi- The basic principles of surgical arthrodesis include
nation of a steroid (e.g. triamcinolone or methylpredni- removal of the remaining articular cartilage; internal
solone acetate) and HA can also be used IA in horses fixation of P1 and P2 with screws, plates, or a combi-
with acute disease to reduce inflammation and slow the nation of plates and screws; compression across the
progression of the disease. Intramuscularly or IA poly- joint surface; accurate alignment of the phalanges; and
sulfated glycosaminoglycans (PSGAGs), IV HA, and variable periods of external immobilization with a
oral nutraceutical supplements are also commonly used. half‐limb cast. The authors prefer a single dorsally
There is some debate as to whether corrective shoeing applied 4.5‐mm, narrow, 3‐hole LCP with two 5.5‐mm
can benefit horses with PIP joint problems. Changing transarticular screws in most horses (Figure 4.92). In
heel height appears to have much more effect on altering very large horses two plates with transarticular screws
flexion and biomechanical forces of the DIP joint than may enhance stability. This technique of a dorsal plate
the PIP joint. In addition, raising the heel decreases the with transarticular screws is thought to improve the
strain on the DDFT but increases strain on the SDFT comfort level of horses in the immediate postoperative
and the suspensory ligament. Therefore, adjusting heel period and requires casting for only 2 weeks postop-
34
height may not be beneficial in horses with PIP joint eratively to optimize surgical wound healing.
31
problems. However, the hoof‐pastern axis should be Cancellous bone grafting is usually unnecessary, but
corrected if abnormal because either a broken‐forward forage or osteostixis of the subchondral bone around
or broken‐back hoof‐pastern axis can contribute to the joint may promote faster arthrodesis, especially in
problems within the PIP joint. In general, the feet should older horses that have very dense sclerotic bone.
be trimmed and balanced, and shoes applied that mini- Bilateral forelimb or bilateral hindlimb arthrodesis
mize break‐over forces and provide good lateral and may also be performed successfully.
medial support. See Chapters 8 and 12 for more infor- Following a routine arthrodesis, the cast is removed
mation on corrective shoeing. after 2 weeks, which is adequate time for the surgical
wound to heal. When minimally invasive procedures
31
can be used on moderately to severely affected OA
Surgical Treatment joints, horses can be placed in a bandage only after sur-
Surgical treatment for OA of the PIP joint consists of gery. Arthrodesis for phalangeal fractures usually
74
arthrodesis, which is aimed at eliminating motion within require a longer period of external immobilization.
the joint, thereby decreasing pain and lameness. Natural Postoperative stall confinement is recommended for a
ankylosis of the PIP joint may occur, but it is often a total of 8–12 weeks with introduction of hand‐walking
long, painful process with variable results. Surgical exercise during this time. For the second 2–3 postopera-
arthrodesis is generally considered a better solution with tive months, horses are either small paddock confined or