Investigations on the canine stifle joint angulation with respect to the rupture of the cranial cruciate ligament and with special consideration of the tibial plateau

Objective: Comparative study on the posture of the stifle joint in dogs with and without cranial cruciate ligament rupture (CrCLR). Material and methods: Stifle joint angle (A healthy limbs: 119.3 degrees, diseased limbs: 117.7 degrees; B 122.2 degrees), and the angulation of the tibia axis and the tibial plateau in relation to the horizontal were measured and compared in 61 dogs with (A) and 63 dogs without (B) a CrCLR. Results: Stifle joint angle, angulation of the tibial plateau to the horizontal (A healthy limbs: -7.4 degrees, diseased limbs: -9.0 degrees; B -2.0 degrees), and angulation of the tibia axis to the horizontal (A healthy limbs: 58.3 degrees, diseased limbs: 56.9 degrees; B 63.4 degrees) were significantly different between the groups. In dogs with unilateral CrCLR significant differences between the healthy and the diseased limb were detected in the stifle joint angle (healthy: 119.2 degrees; diseased: 116.5 degrees) and the angulation of the tibial plateau to the horizontal (healthy: -7,4 degrees; diseased: -9,9 degrees). The angulation of the tibial plateau to the horizontal correlated particularly with the angulation of the tibia axis to the horizontal (A r = 0.944; B r = 0.946). Conclusions: Though significant,the described differences were small. It was concluded that the CrCLR does not lead to clinically relevant changes of the hindlimb posture in the standing dog. The tibial plateau angle according to Slocum does not correlate with the stifle joint angle. Clinical relevance: A CrCLR leads to minor changes in stifle joint posture. Neither the stifle joint nor the tibial plateau angle could be supposed to be predisposing factors for a CrCLR. There seems to be no indication to take the stifle joint angle into consideration when planning a TPLO procedure.