Page 613 - Adams and Stashak's Lameness in Horses, 7th Edition

Lameness of the Distal Limb 579

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Figure 4.157. Open, articular, comminuted proximal fourth
metatarsal fracture (arrow) that was initially debrided and treated
conservatively. Infection persisted and the entire fourth metatarsus
was removed.

portion of the splint and the cannon bone using 3.5‐mm
screws. If the fourth metatarsal bone is involved, bone
plates may be abandoned for complete removal of the
splint bone. If placement of a plate is felt to result in
implant infection, the proximal portion can just be left
and, if luxation occurs, can be addressed at that time.
This may give adequate time for the wound to clean up
Figure 4.156. Chronic middle splint fracture with secondary and decrease the chance of infecting the repair.
drainage and periosteal reaction that is best treated with surgical For an optimal cosmetic end result, bandages are
debridement and removal of the distal fragment. maintained postoperatively. The horse should be main-
tained in a stall for at least a total of 6 weeks. Hand‐
walking exercise can begin at about the second week
Conservative treatment with local lavage, systemic after surgery, and free exercise can begin after 6 weeks.
antimicrobial therapy, and local antimicrobial therapy Training is usually initiated after 2–3 months of rest and
using regional limb perfusion with or without intra‐ is totally dependent on the degree of soft tissue damage
articular injections can be successful. A recent study associated with the fracture site.
found that 11/12 horses with open proximal fractures
responded favorably to medical treatment. 63 Prognosis
Surgical treatment can involve simple debridement of
the wound with removal of any loose bone fragments. If For distal splint bone fractures, the prognosis for
there is any concern about intra‐articular communica- return to performance depends on the severity of sus-
tion, the joint should be sampled and lavaged during pensory desmitis, not on the radiographic healing of the
surgery. These procedures can be performed under fracture. In a retrospective study of 34 cases of distal
17
standing sedation and local anesthesia or can be per- splint fractures without SL desmitis, 75.3% of the horses
formed under general anesthesia. A drain can be placed returned to previous levels of performance, and only
to facilitate drainage postoperatively. Sequestrum for- 50% of the horses with SL desmitis accompanied by the
mation may occur and require further surgical interven- fractured splint resumed to previous levels of perfor-
tion at a later date. Cancellous bone grafts are useful for mance. In another series with an increased percentage
65
treating nonunion fractures in this area. of SL desmitis, only 25% of the horses returned to previ-
If more than two‐thirds of the splint bone is removed ous levels of performance. 17
and it appears unstable and active infection is not pre- The prognosis for comminuted closed splint bone frac-
sent, a small bone plate can be secured to the proximal tures is good to excellent with or without surgery, par-