Page 246 - Canine Lameness

218 14 Elbow Region

Dog apparently predisposed. Lesions may occur anywhere in the body, with the pelvic limb and
tongue most commonly affected (Tafti et al. 2005). Recently a case report described calcification of
the triceps muscle in a Rottweiler (Tambella et al. 2013).
Mineralization occurs because of deposition of serum calcium areas of tissue damage due to
trauma (including surgical intervention), necrosis, inflammation, or neoplasia. The patient should
be evaluated for elevated calcium levels and screened for neoplasia. Surgical excision has been
reported.
In people, a similar well-recognized condition, heterotopic ossification (defined as the formation
of ectopic lamellar bone in soft tissues), is categorized as traumatic, neurogenic, and genetic
(Balboni et al. 2006).

14.14.2 Radioulnar Ischemic Necrosis
Radioulnar ischemic necrosis (RUIN) (Figures 14.12A, B) describes an osteolytic lesion at the level
of the interosseous ligament (Lisbeth et al. 2018). The disease has been described in a Jack Russell
Terrier and Golden Retriever (Deffontaines et al. 2016), although the authors have seen this find-
ing in several other breeds. Although the etiology is unknown, tearing of the ligament with sec-
ondary desmitis/enthesiopathy and potential ischemia is suspected. This condition is an important
ELBOW REGION plastic disease. The location at the radioulnar ligament is key for differentiation of these from
differential diagnosis since presence of the osteolytic lesion may rise suspicion of fungal or neo-

RUIN. In both reported cases, the patients presented with a thoracic limb lameness that resolved
after treatment (nonsurgical or ulna ostectomy).

14.14.3 Triceps Tendon Disruption

Rupture or avulsion of the triceps tendon has been described in approximately 20 cases in the
veterinary literature (Earley et al. 2018), with most of these dogs presenting with a history of
trauma. In addition, prior surgery or steroid administration has also been reported. The most
frequently reported treatment consists of surgical repair followed by immobilization of the elbow
with a trans-articular fixator or splint. Important differential diagnoses include a fracture of the
olecranon or soft tissue neoplasia weakening the muscle predisposing it to rupture. Therefore,
diagnostics should include at least radiographs and ideally ultrasound to evaluate the muscle for
structural abnormalities inconsistent with a traumatic rupture. Advanced imaging such as MRI
has also been reported.

14.14.4 Elbow Region Neoplasia
Neoplasia of the elbow region is observed infrequently. Nonetheless, tumors of the synovium and
triceps muscle should be considered as differential diagnoses. Both are difficult to diagnose with
radiography and therefore additional imaging and/or diagnostics should be considered if neoplasia
is suspected. Further details about neoplastic conditions affecting the region are provided in
Chapters 11 and 17.

14.14.5 Miscellaneous Other Conditions
Other rare causes of lameness associated with pathology in the elbow region include a subchon-
dral bone cyst of the ulnar trochlear notch (Makielski et al. 2015); bilateral bone cysts affecting the