Page 197 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

172 CHAPTER 1

VetBooks.ir OSSEOUS CYST-LIKE LESIONS Aetiology/pathophysiology
OCLLs develop in a similar way to other OCLLs.
Definition/overview
Elbow OCLLs occur in the proximomedial aspect Rarely, cystic lesions can develop secondary to injury
to the collateral ligament.
of the radius or, less commonly, the distal humerus.
Clinical presentation
1.329 Horses present with variable lameness, which may be
worse when lunged in a circle with the limb on the out-
side. There are usually few localising signs, although
lameness may worsen following upper limb flexion.

Differential diagnosis
Elbow OA; collateral ligament injury.

Diagnosis
Diagnosis is made through localisation to the elbow
joint following diagnostic analgesia. Standard
radiographic projections (particularly craniocau-
dal views) usually demonstrate a cystic lucency
(Fig. 1.329). Nuclear scintigraphy will show
increase radiopharmaceutical uptake in the region
of the cyst. Evaluation of radiographic evidence of
OA is important prognostically.

Fig. 1.329 Craniocaudal radiograph of the elbow region Management
showing a well-demarcated osseous cyst-like lesion in the OCLLs of the elbow can be managed conservatively
proximomedial radius surrounded by a sclerotic margin. or surgically. Intra-articular medication (hyalura-
non/corticosteroids) can improve clinical signs.
1.330 Extra-articular curettage of the cyst, with or with-
out bone grafting or other osteoinductive substitute,
may lead to resolution of clinical signs but filling of
the cyst is unpredictable (Fig. 1.330).

Prognosis
Prognosis is usually better with surgical than con-
servative management, although evidence of joint
disease will reduce outcome.

ELBOW SUBLUXATION

Definition/overview
Subluxation of the radiohumeral joint.

Fig. 1.330 Intraoperative craniocaudal radiograph Aetiology/pathophysiology
showing an extra-articular approach to enucleation Luxation usually occurs due to severe trauma/
of a medially located osseous cyst-like lesion in the disruption of the elbow joint and supporting struc-
proximal radius. tures (e.g. collateral ligament avulsion). These