Locking compression plates versus locking plates for tibial plateau levelling osteotomy in dogs: progression of osteoarthritis, bone healing score and lameness degree.

Background: The partial or complete cranial cruciate ligament rupture is a common skeletal disease affecting the stifle joint in dogs. The tibial plateau levelling osteotomy, performed with several synthesis systems, changed the approach to its treatment in dogs. The aim of this study was to compare two types of fixation implants, locking compression system and locking system, evaluating radiographically the progression of osteoarthritis of the stifle joint in dogs with complete cranial cruciate ligament deficiency treated surgically with tibial plateau levelling osteotomy. Moreover, we evaluated bone healing and lameness scores to show biomechanical effects by the implant used. Twenty-eight dogs, who met the inclusion criteria, were divided into two groups. Group A: 14 dogs treated using locking compression plates; Group B: 14 dogs treated using locking plates. Radiographic osteoarthritis scores were evaluated up to 1 year following tibial plateau levelling osteotomy. At each visit, animals were clinically and radiographically assessed. Each dog was evaluated before (T0) and after two (T2) and twelve (T12) months after the surgery. At T2 the stage of bone healing was evaluated. The clinical follow up was performed before the surgery and at 10, 15 and 20 days after the surgery, grading the lameness at walk and trot.

Results: An increase in osteoarthritis score at T12 versus T0 in both groups was detected. A decrease of the lameness score was observed in Group A versus Group B. The healing score system at T2 showed a lower score in Group A versus Group B.

Conclusions: The osteoarthritis score following tibial plateau levelling osteotomy did not differ when comparing the two different fixation systems. The locking compression system allowed a more rapid functional recovery of the limb and a quicker bone healing than the locking system. Locking compression system should be carefully considered for dogs subjected to tibial plateau levelling osteotomy surgery, because it may reduce the recovery time.