Abstract
Background: Fractures of the paracondylar process of the
occipital bone may cause headshaking, neck pain and neurologic deficits.
The condition is being recognized more frequently with increasing
availability of computed tomography. However, to date only limited
information is available as to presentation, treatment, surgical
approach and outcome. Objectives: To describe the clinical
signs, imaging findings, treatment, surgical approach and outcome in
three horses diagnosed with paracondylar process fracture. Study
Design: Retrospective case series. Methods: Clinical records
and diagnostic images of affected cases were reviewed, with informed
owner consent. Results: Two cases with ventral fractures
presented with neck pain and stiffness, one of which had a primary
complaint of poor performance while the other also displayed headshaking
and other behavioural changes. A third case with a more dorsal fracture
presented with acute facial nerve paralysis. Diagnosis was by computed
tomography in all cases. Conservative management resulted in improvement
in all cases with available follow-up, although mild residual neurologic
deficits remained in one. Repeated recurrence of clinical signs after
prolonged periods of remission necessitated surgical removal in one
case, which was readily accomplished with the aid of ultrasound
guidance, and led to rapid resolution of clinical signs without
significant post-operative complications. The surgical approach is
described. Main Limitations: Limited follow-up was available
for some cases. Conclusions: Paracondylar process fracture
should be considered as a differential diagnosis for headshaking, neck
pain, poor performance and facial paresis, and is a justification for
performing computed tomography in such cases. A multi-disciplinary
approach is beneficial due to the potential for orthopaedic, neurologic,
ophthalmologic and behavioural clinical signs, with additional need for
expertise in diagnostic imaging and pain management. Surgical fragment
removal should be considered in cases that do not respond adequately to
conservative management.