Angular limb deformities in dogs refer to any abnormality associated with the alignment of the bones in a limb. These are deviations from a normal straight bone to curved conformation. These deformities can affect the front (forelimbs) or rear (hindlimbs) limbs and may occur in young puppies during their growth phase. Young dogs have growth plates that are responsible for the length and shape of a bone. Should these growth plates be damaged, deformities can occur.
The Diagnosis of Angular Limb Deformities in Our Four-legged Friends
There are a number of steps involved in diagnosis and evaluation of angular limb deformities. These include:
- A patient’s signalment and history: Information about the dog’s breed, age, diet, growth rate, previous injuries, and any signs of pain or lameness is valuable in understanding the potential causes of the deformity. Often there is a history of a previous injury that indicates a growth plate could have been injured at a previous time.
- Clinical examination: A general physical exam, orthopedic evaluation and gait analysis are important aspects of evaluation. A patient’s limb conformation, weight-bearing, deviations from the normal alignment of the limbs based on the breed are considered.
- Radiographic evaluation: Utilization of radiographs (x-rays) are an important starting point for evaluation of a patient’s limb. Evidence of previous trauma and clues as to why a patient developed a deformity may be present on X-rays. This can aid in developing proper treatment plans. However, it is important to remember that x-rays are a 2-dimensional representation of a 3-dimensional object and slight twisting of a limb can make a bone look deformed when it is not and can also make deformed legs look straight when they are not.
- Advanced imaging: CT has greatly improved our understanding of deformities and has the advantage of allowing us to evaluate the limb in three dimensions where this cannot be accomplished with radiographs.
- 3D Printing: The surgeons at Spry Companions sometimes utilize 3D printing to aid in our analysis of a patient’s confirmation. Nothing is better than holding a replica of a particular patient’s bone in your hand. We can utilize data from the CT scan to reproduce the exact size and shape of a bone in question.
Advanced Treatment of Angular Limb Deformities
Treatment of deformities involve surgery to correct bony abnormalities. These surgeries are known as corrective osteotomies. In its most simple form, deformed bone is cut and moved until the alignment of the bone is straight again. Where and how much bone is cut is based on pre-operative planning that utilizes CT images and a limb alignment analysis. In many cases, a customized cutting guide is fashioned using a 3D printer. This ensures exact placement of the osteotomy at the correct angle to maximize correction of the deformity. Once complete, the bone is stabilized with a bone plate or other fixation until the bone is fully healed.