Front Matter

324 Canine Sports Medicine and Rehabilitation

Metacarpal and sesamoid injuries

Cause

The most common injuries are metacarpal frac­
tures. Currently, there are few studies evaluat­
ing metacarpal fractures, and of those available
most are retrospective in nature (Muir &
Norris, 1997; Kapatkin et  al., 2000). It appears
that the cause of metacarpal fractures is usu­
ally trauma. Metacarpal fractures are more
common than metatarsal fractures and most
fractures occur in the middle or distal regions
of the bones (Muir & Norris, 1997). In racing
Greyhounds a specific distribution of metacar­
pal fractures has been described likely due to
stress and possibly fatigue leading to fissures
and ultimately a fracture (Bellenger et al., 1981).

Metacarpal fractures in racing Greyhounds

usually occur at metacarpal V on the left and

metacarpal II on the right.

Sesamoid disease consists of fractures and

fragmentation. There is conflicting evidence in

the literature on whether these conditions are

different or the same (Kapatkin et  al., 2012).

Racing Greyhounds and Rottweilers are the

two most common breeds to have a clinical

lameness associated with sesamoid disease,

while in many other breeds it may be an inci­

dental finding (Cake & Read, 1995). Theories

for sesamoid disease include trauma, congeni­

tal disorders of ossification, osteoarthritis from

abnormal forces, and osteonecrosis from vascu­

lar compromise. Sesamoids II and VII have

fewer vascular foramina than the other sesa­

moids (Cake & Read, 1995).

Diagnosis

Dogs with metacarpal fractures may exhibit

varying degrees of lameness from non‐weight

bearing in the acute phases to intermittent

lameness with chronic fractures. Swelling

may be noted with pain and crepitus upon

palpation in acute cases. In chronic cases a cal­

lus or firm fibrous tissue may be palpated at

the fracture site. Given the lack of soft tissue

coverage,  wounds should be carefully evalu­

ated. Radiographs are the mainstay in diag­

nosing metacarpal fractures (Figure 12.34).

Attention should be paid to the number of

metacarpals fractured and the degree of

displacement.

Patients with sesamoid disease can have

variable degrees of lameness, pain, swelling,

and effusion. With chronic disease, there may

be thickening with a reduction in joint flexion.

It is very important to rule out other orthope­

dic disease conditions in the thoracic limb

before assuming the lameness is due to sesa­

moid disease. Radiographs are needed to doc­

ument evidence of sesamoid disease (Figure

12.35); however, the diagnosis can sometimes

be challenging on standard orthogonal radio­

graphic projections. Oblique views are typi­

cally needed to identify the fracture or

fragmentation. Findings include two or more

fragments with sharp or smooth borders, oste­

ophytosis, or dorsal displacement, and in

Figure 12.33 Immediate postoperative image following
a minimally invasive pancarpal arthrodesis using the
pancarpal arthrodesis plate. Note the three small
incisions used for the procedure.