Tibial Plateau Leveling Osteotomy (TPLO)

- Indications 

Tibial plateau leveling osteotomy (TPLO) is an effective procedure for dogs with complete or partial tears of the cranial cruciate ligament. The objective of the TPLO is to attain a tibial plateau slope of approximately 5º so that the cranial tibial

thrust can be effectively controlled by the caudal cruciate ligament and the active muscular constraints (hamstrings and biceps femoris muscles) of the stifle.

- Preoperative planning

Palpation of a positive cranial tibial thrust or cranial drawer movement indicates a rupture of the cranial cruciate ligament. Stifle radiographs often show evidence of joint effusion and degenerative joint disease. Tibial plateau slope is measured from mediolateral radiographs of the tibia made with the beam centered on the stifle. The femoral condyles and the distal tibial malleoli should be superimposed respectively. Place a tracing sheet over the radiograph. Identify and mark the center of the talus. Identify and mark the center of the two tibial spines. Connect the marks to identify the long axis of the tibia. Draw a line from the cranial margin to the caudal margin of the medial tibial plateau. Tibial plateau slope is measured between the medial tibial plateau line and a line drawn perpendicular to the long axis of the tibia [24]. Craniocaudal radio graphs of the tibia are evaluated to identify any rotational or angular deformity of the tibia.

- Surgical procedure 

Explore the stifle to assess and treat meniscal damage and to perform a medial meniscal release. Expose the medial aspect of the proximal tibial metaphysis and circumferentially elevate the surrounding muscles to prepare for the osteotomy. Place a jig to secure the proximal and distal tibial segments and to serve as a guide for the osteotomy. Create a semicircular osteotomy with a biradial saw blade. Rotate the proximal segment until the plateau is level. Stabilize the tibia with a tibial plateau leveling plate.

- Specific postoperative care

Postoperative care is similar to plated fracture management. Osteotomy healing should occur within 6–12 weeks. Complications include tibial tuberosity fractures, implant-related problems, wound-related problems, and infection。