Tibial Plateau Leveling Osteotomy or Tibial Tuberosity Advancement?

OBJECTIVE: To review the proposed biomechanical basis of the tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA) and recommendations for these techniques. STUDY DESIGN: Literature review. METHODS: Literature search through Ovid Medline Plus, Pub Med, CAB Abstracts, and conference proceedings abstracts (August 1983 to March 2008). RESULTS: TPLO and TTA stabilize the cranial cruciate ligament (CrCL) deficient stifle joint neutralizing tibiofemoral shear forces by altering the geometry of the proximal aspect of the tibia. Stability is attained by placing the joint in a functionally greater flexion angle so that the patellar tendon angle (PTA) remains < or =90 degrees. Both procedures target slightly differing endpoints, the significance of which is unknown. Many of the biomechanical variables investigated appear to favor the TTA; however, TPLO appears to have more clinical versatility. The clinical ramifications of these differences remain to be determined but the reported results for both procedures are comparable. Only the early results of these techniques have been reported, which is reflected in the relatively high number of complications associated with the early learning curve for both procedures. CONCLUSIONS: There are many similarities between TPLO and TTA although it remains to be fully elucidated if either procedure is superior and under what conditions. CLINICAL RELEVANCE: TPLO and TTA are effective at returning dogs with a CrCL-deficient stifle joint to good limb function. Surgeon discretion and case selection drive selection of TPLO or TTA based mostly on anecdotal evidence and personal experience.