Canine Patella Surgery (TCT + Sulcoplasty)

• A lateral parapatellar approach and lateral arthrotomy is used to examine the trochlear groove and ridges, the retro-patellar surface, the cranial and caudal cruciate ligaments and menisci.
• Caudal pressure of the patella during growth stimulates formation of the trochlear groove so patients with patella luxation may have a shallow sulcus.
• Cranial cruciate ligament rupture is often concurrent with medial patella luxation, especially in dogs with adult or acute onset of clinical signs and needs to be addressed if present.

• The trochlear groove is deepened and widened using a trochlear wedge or block recession so approximately 50% of the patella protrudes above the trochlear ridges. These techniques preserve articular cartilage.
• A sulcoplasty is only performed if there is an inadequate groove, as judged intra-operatively. For some patients a TCT alone is sufficient.

• An osteotomy of the tibial crest is created usually maintaining a distal bridge of bone. This allows the tibial crest to be displaced laterally (for MPL) or medially (for LPL), aligning the patella tendon with the trochlear groove.
• The tibial crest is secured with one or two arthrodesis wires and (usually) a tension band wire. The configuration of implants changes depending on individual patient conformation.

Rebalance of periarticular soft tissues

• Medial patella luxation causes contraction of the medial retinaculum (joint capsule and fascia) and laxity of the lateral retinaculum. Most patients will have a lateral imbrication on closure and some patients need a medial release.
• These procedures augment the TCT but are never used as a primary repair as they do not address the underlying anatomical malalignment present in patients with patella luxation.