Transarticular elastic external skeletal fixator correction of a stifle rotational deformity and patellar luxation in a dog

Authors: 
Tiffany Chen, Georgia Bosscher, Derek Fox, Courtney Arnoldy, Jason Bleedorn
Vet Surg. 2020 Oct 13. doi: 10.1111/vsu.13524.

Objective: To report the preoperative evaluation, treatment with transarticular elastic external skeletal fixation (ESF), and outcome of a dog with bilateral medial patellar luxation (MPL) and stifle rotational deformity.

Animal: One nonambulatory, 2.5-month-old, 7.5-kg mixed-breed intact female dog.

Study design: Case report METHODS: Complex pelvic limb deformities were assessed with physical examination and computed tomography (CT) and characterized as bilateral grade 4 MPL and 90° internal rotation of the tibia in relation to the femur. Three-dimensional imaging and bone models were used to quantify the deformity and rehearse surgical correction. Transarticular elastic chains between ESF pins in the femur and tibia were used to gradually correct stifle rotational malalignment on each pelvic limb. Soft tissue releases, imbrication, and a transphyseal staple were used to correct the patellar luxation (PL) and femoral varus. The dog was reevaluated for 1 year postoperatively.

Results: Short- and long-term management included intensive physical rehabilitation to increase pelvic limb strength and function. Surgical treatment resulted in resolution of the PL and neutral stifle alignment. The dog was able to ambulate with persistent decreased range of motion of the stifle.

Conclusion: Transarticular elastic chains and femoral physeal stapling improved the function of a dog with severe bone deformities and PL in a growing dog.