Table 1. Confounding factors for case exclusion.

Confounding factor	Number of Dogs
Previous stifle surgery	30
TPLO treatment for a stable partial cruciate rupture	9
TPLO implant removal after surgery	8
Implant-associated infection	2
Polyarthritis	1
Premature physeal closure in the distal femur	1
Femoral osteochondritis dissecans	1
Femoral osteoproliferation	1
Pelvic limb amputation	1
Popliteal tendon avulsion	1
Failed tibial plateau leveling osteotomy	1
Femoral head ostectomy	1

Note: 55 dogs in total were excluded during case filtering because of confounding clinical factors. More than one confounding factor was found in some dogs.