Limb Deformity

Deformities of the Long Bone Axis

Deformities of the long bone axis, whether angular, torsional, or combined, result in mechanical lameness, pain, and abnormal posture.

Angular Limb Deformity Causes

Angular limb deformities can be caused by congenital malformations, trauma to growth plates, nutritional imbalance, or fractures healing in malunion. Chondrodystrophic breeds such as Basset Hound, English Bulldog, French Bulldog, Shih Tzu, Beagle, Pembroke Corgi, Pug, Maltese, and Lhasa Apso are particularly prone to these deformities.

Diagnosis

Limb deformities are complex causes of lameness, diagnosed through clinical examination and radiographic imaging or CT scan. Radiographic examination measures the centre of rotation (CORA) to evaluate joint orientation and bone axes. Three-dimensional printing models and customised implants based on CT scans are increasingly popular for pre-surgery planning.

Treatment

Surgery is the primary treatment for correcting deformities and restoring normal leg function. The procedure involves one or more osteotomies (bone cuts) and realignment of the bone axes. Metallic implants, such as External Skeletal Fixators (ESF) or Plates and Screws, are then used to fix the aligned bone. Here's the corrected version:

"The osteotomy cut is based and planned on XR images. Alternatively, it can be performed using 3D printing guides. These are based on CT scans, and the 3D printing models provide guidance (Vet3D)."

ESF

Less invasive than plates, suitable for correcting CORA close to the joint line. However, post-operative care is demanding due to the frame's presence, requiring recurrent rechecks for pin issues and frame integrity.

Plates and Screws

More technically demanding during surgery but offer easier post-operative care with internal implants. They allow an earlier return to function due to the stiffness of the construct.