History:

A 1 year old, male mix dog, weighting 19,5 kg, was presented for consultation because of right hind leg lameness. The condition, followed several surgical attempts to treat femoral fracture of the same leg.

 The owner reported that the dog was a stray dog and five months ago was rescued, suffering trauma of the right hind leg. An open approach and fixation by pin and cerclage technique was accomplished at first place. The approximate age at that time was about 7 months. Because of a sub-optimal stability, fixation failure followed and a second surgery was accomplished 3 weeks after the primary. Osteosynthesis with 3,5 locking plate was done and low-grade infection was isolated from the surgical wound. A month later, loosened screws caused fracture nonunion and development of significant femoral varus deformity. Manwhile, fortunately, the infection had been successfully treated. Last revision with IM Kuntscher and ex fix combination, has lead to fracture healing and clinical improvement. The owner reported reasonably good limb function until 2 weeks ago, when lameness resurfaced and gradually deteriorated.

Clinical exam:

During our examination we found grave right hind leg lameness (III/IV), visible shortening of the limb, moderate muscle atrophy, tendency for tarsal and stifle hyperextension. A pain was localized in the right knee, which also showed restricted flexion ROM - up to 60 degrees; Medial patellar luxation (III degree) was found; cranial tibial compression test was negative; the other limb’s joints were non painful. The neurological tests were normal.

Diagnostics:

Orthogonal radiographic views of the right femur were performed. Right femoral malunion was diagnosed and appreciated as a cause for the MPL. 

Question yourself:

Evaluating the radiographs, how would you classify the femoral deformation? What deviations do you see on the X-rays?

-femur shortening
-sagital plane deformation- excessive procurvatum
-frontal plane deformation- excessive distal femoral varus
-frontal plane deformation- lateral distal segment translation
-axial plane deformation- internal femoral torsion
-all above

Which deformities you will consider clinically important to correct?

If you contemplate a corrective femoral osteotomy/ectomy, how would you approach it:

-    Distal femoral ostectomy- closing wedge, lateral approach and plating
-    Distal femoral osteotomy- opening wedge, medial approach and plating
-    Distal femoral osteotomy- radial cut
-    Dynamic femoral lengthening and deformity correction, using linear distractor.