Page 332 - Canine Lameness

304 18 Tarsal Region

OCD lesions), with decreased range of motion in the tarsus in both flexion and extension.
Tarsocrural joint effusion is present. The DDF tendon sheath may be palpable as a distended and
painful vertical swelling on the plantaro-medial aspect of the tarsus and distal tibia.
Orthogonal radiographs may show swelling of the DDF tendon sheath and opacities in the region
of the tendon caudal to the tibia (Figure 18.12). Oblique views can be useful for highlighting
additional fragments. CT is the most sensitive test for showing all of the fragments within the
sheath, which is useful for guiding fragment removal surgery but generally not necessary for
diagnosis of this condition. Ultrasonography of the tendon sheath can also be used to localize
swelling to the DDF tendon sheath and find fragments.
TARSAL REGION ments from around the tendon. However, lameness due to the secondary degenerative changes
Lameness attributed to irritation of the DDF can be treated with removal of the osteochondral frag-

may persist following treatment.

18.7.5 Tarsal Region Neoplasia
Neoplasia is much less frequently observed in the tarsal region than in the carpal region, but
tumors of the synovium (Figure 18.12) and osteosarcoma should be considered as differential diag-
noses. Further details about neoplastic conditions are provided in Chapters 11 and 22.

18.7.6 Miscellaneous Other Conditions
While degenerative changes of the distal tarsal joints are frequently identified as an incidental
finding, lameness associated with centrodistal OA has been described in Greyhounds and Border
Collies (Guilliard 2005). Affected dogs show a pain response if the metatarsus is supinated while
the limb is extended behind the dog and the calcaneus is fixed in place.
The authors have diagnosed rupture of the tarsal extensor retinaculum as a cause of lameness,
but this has not been reported in the peer-reviewed literature.
Dee (2015) has reported lameness (often bilateral) in working German Shepherds associated
with thickening and presumed repetitive trauma to the cranial tibial tendon of insertion.
Fragmentation of the medial malleolus has been reported in a small number of young large-
breed (mostly Rottweiler) dogs; about half of the affected dogs had concurrent talar ridge OCD
(Newell et al. 1994). The association of this condition with lameness is unclear.

References

Armstrong, A.J., Bruce, M., Adams, R. et al. (2019). Injuries involving the central tarsal bone in
nonracing dogs: short-term outcomes and prognostic factors. Vet Surg 48 (4): 524–536.
Aron, D.N. and Purinton, P. (1985). Collateral ligaments of the tarsocrural joint an anatomic and
functional study. Vet Surg 14 (3): 173–177.
Butler, D., Nemanic, S., and Warnock, J.J. (2018). Comparison of radiography and computed
tomography to evaluate fractures of the canine tarsus. Vet Radiol Ultrasound 59 (1): 43–53.
Carmichael, S. and Marshall, W.G. (2018). Tarsus and metatarsus. In: Veterinary Surgery: Small
Animal, 2e (eds. S.A. Johnston and K.M. Tobias), 1193–1209. St. Louis: Elsevier.
Corr, S.A., Draffan, D., Kulendra, E. et al. (2010). Retrospective study of Achilles mechanism
disruption in 45 dogs. Vet Rec 167 (11): 407–411.