278 Canine Sports Medicine and Rehabilitation
Pelvic limb amputation compensatory
changes
What about the pelvic limb? Kirpensteijn et al.
(2000) found that after pelvic limb amputation
the remaining pelvic limb carries 26% of total
body weight, while the thoracic limbs each
carry 37%. This implies that regardless of
whether a pelvic or thoracic limb is amputated,
the thoracic limbs carry an increased load
(~17% for a thoracic limb amputation and 7%
increase for each pelvic limb amputation) and
that pelvic limb amputation may have less
severe overload consequences than thoracic
limb amputation. Further, one might intuitively
suspect, based on this weight distribution dis
parity, that larger breed dogs would have more
difficulty adapting to amputation than smaller
breeds, although the 1999 Kirpensteijn et al.
study did not support this. Conversely,
Dickerson et al. (2015) found that client‐
assigned quality of life scores had significant
negative correlations with preoperative body
condition score and body weight. More work is
needed to expand on these findings, in parti
cular additional kinematic data for long‐
term outcomes. However, until such studies
are performed, it may be prudent to manage
all prospective amputees with an eye toward
prevention of overload regardless of limb,
breed, weight, or body type.
Recent studies have examined the kinematic
consequences of pelvic limb amputation.
Although increased weight distribution is rela
tively small for the remaining pelvic limb,
rotation forces about the transverse and sagittal
axes of the trunk are altered. Pelvic limb
amputation removes the normal contralateral
limb support for the thoracic limb. In this
regard, the limbs and the vertebral column
(including their myofascial support structures)
must compensate. Data support involvement of
the spine; pelvic limb amputees laterally bend
the vertebral column to place the remaining
pelvic limb closer to the ipsilateral thoracic
limb. Hogy et al. (2013) refer to this as a “unique
laterally deviated gait when the pelvic limb is
in propulsion.” In this case, in contrast with
the quadruped, the long axis of the thoracolum
bar vertebrae is not parallel to forward motion.
Further findings salient to vertebral column
motion included the cyclical movement of the
head upward during propulsion of the contralat
eral thoracic limb. This was presumed to assist in
elevation of the center of mass. The head was
subsequently moved downward at the termina
tion of contralateral thoracic limb swing phase
and in to stance phase. Thus, there is increased
cervical spine range of motion when compared
with a quadruped. The remaining pelvic limb
acts as a compliant strut, and is shifted cranially
and medially to maintain stability and aid in
propulsion. This causes increased flexion and
rotation of the lumbosacral spine. The long‐term
implications of these spinal compensations are
not known, and further studies are needed.
Hogy et al. (2013) also found that increased
range of motion is present in the remaining tar
sus. It was presumed that this is a compensatory
mechanism to maximize efficient propulsion due
to elastic recoil of the calcaneal tendon and associ
ated musculature. This was confirmed by Goldner
et al. in 2015. This additional stretch/loading of
the calcaneal tendon and digital flexors may
result in chronic strain of these soft tissues, in(A)
(B)
Figure 11.10 (A) The pathomechanical consequences of
thoracic limb loss can be mitigated with the use of a
properly fitted prosthesis. (B) A below‐carpus prosthesis
for amelia of the right thoracic limb distal to the radius
and ulna. (B derived from video.)