Excessive Tibial Plateau Angle Correction Diminishes Cruciate Degeneration

Kenneth A. Johnson, MVSc, PhD, FACVSc, DACVS, DECVS

Excessive tibial plateau angle was recognized as a contributing factor to canine cranial cruciate ligament rupture in a small proportion of cases, some 40 years ago.[1] However, the aetiology of cruciate ligament disease is very complex and still not clearly elucidated, but it is considered to be multi-factorial in nature. Degenerative changes in the canine cranial cruciate ligament are characterized by progressive chondrometaplasia and reduced mechanical properties. Degenerative changes in the cranial cruciate ligament frequently precede progressive rupture of this ligament, but unlike the problem in humans, it is rarely the result of acute mechanical overload alone.

Tibial plateau levelling osteotomy is currently a popular surgical intervention employed for the treatment of this disease, irrespective of the pre-existing tibial plateau angle. Ex vivo cadaveric studies have demonstrated that tibial plateau levelling osteotomy with reduction in the tibial slope to less than six degrees in cruciate-deficient stifle joints diminishes cranial tibial thrust. Furthermore, an arthroscopic observational study suggested that tibial plateau levelling osteotomy slowed progression of articular cartilage degeneration in joints with partial cranial cruciate ligament rupture.

Experimental creation of an excessive tibial plateau angle slope of 40 degrees induced histologic changes in the canine cranial cruciate ligament, similar to the previously described degenerative changes.[2] Most interestingly, when the tibial plateau levelling osteotomy was revised to a plateau angle of ten degrees, the progression of these histologic changes in the cranial cruciate ligament was diminished. This is an important finding—it is the first to provide evidence that tibial plateau levelling osteotomy in dogs could slow progression of the cruciate ligament disease and potentially avert complete ligament disruption. The full details of this investigation by Shimada and colleagues have been published in this issue of the Journal.[2]

Publication History

Article published online:
18 January 2022

• References

• 1 Read RA, Robins GM. Deformity of the proximal tibia in dogs. Vet Rec 1982; 111 (13) 295-298
• 2 Shimada M, Kanno N, Ichinohe T, Suzuki S, Harada Y, Hara Y. Prophylactic efficacy of tibial plateau levelling osteotomy for a canine model with experimentally induced degeneration of the cranial cruciate ligament. Vet Comp Orthop Traumatol 2021; 35: 18-25