Accurately Reduce
and Maintain TPLO Osteotomies
Submitted by Robert Sikes, DVM, Diplomate ACVS | Animal Surgical Group Mobile Practice
How do you accurately reduce and maintain reduction of a tibial plateau leveling osteotomy (TPLO) while testing for tibial thrust before plate application?
Robert Sikes, DVM, Diplomate ACVS, an early disciple and friend of TPLO inventor Dr. Barclay Slocum, shares his solution.
Dr. Sikes utilizes a TPLO reduction pin to maintain reduction but only after careful evaluation of quality radiographs, selection of a TPLO blade, proper surgical approach and completing an accurate osteotomy.
Application of a TPLO reduction pin is a critical part of the TPLO procedure. Designed to supply sufficient thread length to engage both the proximal tibial segment and the plateau segment, reduction pins secure the rotated segment in position to allow testing of the limb for the elimination of cranial tibial thrust. If thrust remains, the pin can be removed, more rotation applied and the reduction pin reapplied.
FIGURE 1 – Reduction | Rotated plateau segment reduced with pointed forceps and maintained with TPLO reduction pin
FIGURE 2 – Plate Application | One TPLO reduction pin is placed over another to determine positioning and avoid pin interference when drilling
FIGURE 3 – Pin Location | TPLO pin driven cranial to caudal, starting lateral and proximal to the insertion of the straight patellar tendon
Important: TPLO reduction pin placement should be proximal to the insertion of the patellar tendon. If placed distally, the insertion point can act as a stress riser and induce fracturing of the tibial tuberosity.
Occasionally, a gap occurs at the cranial edge of the osteotomy before pin placement. Pointed reduction forceps can function well in this scenario to reduce the gap before inserting the TPLO reduction pin.
When using locking TPLO plates, it is sometimes impossible to avoid the reduction pin with the drill bit or a screw. In this case other screws are placed first for stability, then the TPLO reduction pin can be removed to allow for safe placement of the final screw.
Dr. Sikes has performed this reduction method over years of TPLO procedures and continues successfully utilizing it in his Arroyo Grande, California hospital, the Animal Surgical Group.