Effects of the Direction of Two Kirschner Wires on Combined Tibial Plateau Leveling Osteotomy and Tibial Tuberosity Transposition in Miniature Breed Dogs: An Ex Vivo Study.

This study evaluates the impact of Kirschner wire (K-wire) insertion direction on the biomechanical properties of combined tibial plateau leveling osteotomy (TPLO) and tibial tuberosity transposition (TTT) procedures in small-breed dogs with cranial cruciate ligament rupture and medial patella luxation. Twenty-one cadaveric tibiae were divided into two groups; the specimens were divided into two groups; one underwent TPLO-TTT with a proximal pin placement (Group TTP), and the other received TPLO-TTT with a distal pin placement (Group TTD). For both pin placements, two additional subgroups were formed: one with a 0.56 mm tension band (Groups TTP0.56 and TTD0.56) and the other with a 0.76 mm tension band (Groups TTP0.76 and TTD0.76). The tensile force was applied, and failure load and mode were recorded. The distal pin direction in Group TTD0.56 exhibited a significantly higher mean failure load (380.1 N) compared to the proximal pin direction in Group TTP0.56 (302.2 N, p = 0.028). No significant differences were observed among the other groups. This study concludes that distal pin placement can provide similar or improved mechanical stability in cases with limited space for proximal pin placement during combined TPLO and TTT procedures.