Rotation of the femoral trochlea for treatment of medial patellar luxation in a dog

Abstract

A crossbreed dog was presented with non-weight bearing on the right hindlimb and a semi-flexed stifle. Clinical examination and radiographic investigation showed a grade 3 medial patellar luxation, characterised by hypoplasia of the medial trochlear ridge. No other significant skeletal abnormalities were detected. A 180 degrees rotation of the femoral trochlea was the surgical technique chosen to treat the trochlear dysplasia, the aim being to move the normal lateral ridge to the medial side and thereby prevent patellar luxation. This technique was able to restore correct conformation of the femoral trochlea and preserve the integrity of the trochlear groove cartilage, thus potentially retarding the progression of degenerative joint disease. The dog recovered fully and postoperative radiographic examinations showed healing of the rotated trochlea with only mild signs of degenerative joint disease.

Radiographic measurement of the quadriceps angle in dogs

“…The present study was conducted on healthy dogs in order to avoid the presence of QA alterations; animals with skeletal hindlimb abnormalities could have developed PL, a condition which could induce an increase in the QA value if compared to the physiological angle [2,7–10,16,19]. All the dogs included had to have had a hindlimb radiographic image previously analysed in order to have been included this study.…”

“…Decreased anteversion, coxa vara, medial displacement of the quadriceps group, external rotation and/or torsion of the distal femur, lateral displacement of the femoral trochlea, internal rotation and/or medial torsion of the proximal tibia and medial displacement of the tibial tuberosity are some deformities which can cause medial displacement of the extensor mechanism and result in the development of PL [2,9,10]. One or more of these abnormalities can cause a QA value modification.…”

Should gait analysis be a part of clinical orthopaedic reports?

“…The limitations of the experimental design in retrospective studies and case reports dictate that with these study designs, an objective measure of lameness like gait analysis may not be needed and may not strengthen the evidence provided by the study. Indeed, the three orthopaedic studies reported in this issue of JSAP that have lameness as a measure of outcome (Pinna and others 2008, Au and others, 2008, Roch and Gemmill 2008) would not have benefited from gait analysis.…”

Canine medial patellar luxation

“…There is also one case report describing transverse osteotomy of the entire femoral trochlea and rotation of this by 180° for treatment of medial trochlear ridge hypoplasia (Pinna et al . 2008). The ideal trochleoplasty technique would adequately recess the femoral trochlea to prevent MPL recurrence while maintaining as much hyaline articular cartilage as possible to minimise development of OA (Johnson et al .…”