What is TTA (Tibial Tuberosity Advancement)?

Tibial Tuberosity Advancement (TTA) for Cranial Cruciate Ligament Disease in Dogs

Tibial Tuberosity Advancement (TTA) is a surgical procedure used to treat cranial cruciate ligament deficiency in dogs by advancing the tibial tuberosity to alter the biomechanics of the stifle joint, resulting in dynamic stabilization without the need for direct ligament replacement.

Procedure Overview

• TTA involves an osteotomy of the tibial tuberosity followed by advancement and fixation with specialized implants to change the angle between the patellar ligament and tibial plateau 1
• The goal is to achieve a 90-degree angle between the patellar ligament and the tibial plateau or common tangent between femur and tibia in the extended limb position 2
• The procedure neutralizes cranial tibial thrust forces that occur in cruciate-deficient stifles by altering joint biomechanics 1

Surgical Technique

• Standard TTA technique involves:

  • Osteotomy of the tibial tuberosity
  • Advancement using specialized cages (typically 3-12mm)
  • Fixation with plates and screws from the medial aspect of the tibia 1

• Modified techniques have been developed:

  • TTA Rapid: Uses novel implants with simplified instrumentation for faster procedure time 3
  • TTA with Cranial Fixation (TTA CF): Utilizes titanium implants fixed from the cranial side rather than medial side of the tibia 4
  • Modified TTA for large breed dogs requiring advancement >12mm: Uses displaced cages and allogenous bone blocks for additional support 2

Clinical Outcomes

• Success rates are high with 90-96% of cases showing good to excellent outcomes based on owner assessment 1, 4
• Activity level improvement is reported in approximately 90% of dogs following the procedure 1
• Bone healing typically occurs within 6-14 weeks postoperatively 4

Complications

• Overall complication rates range from 30-59%, but most are minor and resolve without additional intervention 1, 3
• Minor complications include:
  • Soft tissue swelling
  • Seroma formation
  • Mild infection 1
• Major complications are less common (4%) and may include:
  • Implant failure
  • Tibial crest displacement
  • Medial meniscal tears
  • Technical errors requiring revision surgery 1, 3

Special Considerations

• TTA can be successfully performed in dogs with unique anatomical challenges, including those with contralateral limb amputation 5
• Radiographic progression of osteoarthritis occurs in approximately 67% of cases despite good clinical outcomes 1
• Proper preoperative planning with accurate measurements is essential to determine the appropriate advancement distance 2

Patient Selection

• Most commonly performed in medium to large breed dogs (average weight 30-40kg) 1, 3
• Suitable for dogs of various ages, with the average age at treatment being 4-5 years 1, 4
• The procedure has been successfully used in dogs with varying durations of lameness prior to surgery (average 6.2 months) 1

TTA represents an effective surgical option for managing cranial cruciate ligament disease in dogs with high success rates and generally favorable outcomes when performed by experienced surgeons.