Pre-operative Planning for Tta

Key Points • Palpation of functional cranial tibial thrust instability during weight-bearing is used to assess knee stability preand post-operatively. • Variation in radiographic landmarks to determine stifle flexion angle (SFA) leads to variable TTA cage size recommendations. Use of the Long Axes Method leads to larger advancement recommendations than Kinematic or Eminence Methods. • Variation in radiographic landmarks to determine patellar tendon angle (PTA) leads to variable advancement recommendations. Use of tibial plateau landmarks leads to larger advancement recommendations than common tangent landmarks. • Variation in measurement methods leads to variable advancement recommendations. Use of virtual TTA planning software leads to larger advancement recommendations than does the transparent overlay method.