TTA (Tibial Tuberosity Advancement procedure) is a relatively recent surgical advancement in the treatment of cranial cruciate rupture in the dog. The TTA procedure advances the tibial crest cranially and secures it in place with a specialised plate and cage implant. This changes the force exerted on the tibia by the quadriceps muscle group effectively negating the usual cranial thrust force on the tibia and causing it to become a caudal thrust, thus functionally stabilising the stifle. In simplistic terms the patella ligament effectively replaces the function of the cranial cruciate ligament.
Your pet is anaesthetised ready for surgery and the area clipped and prepared for sterile surgery. The stifle is approached through a medial incision (inside of the leg). The subcutaneous tissues are dissected and the stifle joint is entered. The joint and menisci are inspected. Damaged menisci are removed and the joint is then closed with high grade synthetic absorbable suture material. This assessment and treatment can also be done by arthroscopy which is less invasive and generally less painful. Once the joint is closed the osteotomy (bone cut) of the tibial crest is begun. The osteotomy is stopped just before the distal (far) end of the tibial crest and the TTA plate is secured to the tibial crest with screws. The TTA cage is placed between the tibial crest and the tibia to brace it in place. The cage is packed with cancellous bone graft. The TTA plate is the secured to the tibial shaft with either screws or a K wire depending on the case and this fully secures the tibial advancement. The subcutaneous tissues are closed with synthetic absorbable suture material and the skin is closed with staples. Radiographs are taken post operatively to ensure correct placement of implants and screws.
What to expect from TTA surgery
Most studies and our clinical experience has been that over 95% of clients regard results of surgery as “excellent” in dogs under 35kg. Obviously one persons assessment of excellent is different from anothers however our impressions with this surgery are that there is a faster return to function, more normal function and better long term relief from symptoms achieved with this surgery compared with other treatment options including conservative (i.e. non surgical) management, graft repair or DeAngelis suture repair. We CANNOT CURE ARTHRITIS!! If your pet has significant arthritic changes in the joint then results will not be as good as if surgery was done earlier. Significant degeneration of the joint can occur in as little as 4-6 weeks! This is why we recommend surgery as soon as possible after injury.
Due to inherent limitations of the TTA surgery it has been our experience that dogs over 30kg do not perform as well. Consequently in large dogs and dogs with very angled tibial slopes we have moved away from TTA as our recommended surgery and now recommend and perform CBLO (CORA Based Levelling Osteotomy) on these dogs. Please see our CBLO page for more information about this technique and why we recommend it for larger dogs.
Does my pet need any care after surgery?
We will usually keep your pet in overnight after surgery for monitoring. Your pet will go home the following day and will need to take antibiotics and pain relief medications for 10 to 20 days. To get the best results from the surgery your pet needs to have follow up visits weekly for 4 weeks. At these visits they will receive an injection (Cartrophen) to help the joint recover from surgery. Additionally they will have physiotherapy and you will be given exercises to do with them at home to help with recovery.
We typically expect your pet to be 20-30% weight bearing at 1 week post op, 40-50% weight bearing at 2 weeks post op, 60-70% weight bearing at 3 weeks post op and around 80% weight bearing at a walk 4 weeks post op. If there is meniscal damage then that will typically delay recovery by 1-2 weeks. We do not recommend off leash exercise until radiographs at 8 weeks post op show good healing of the osteotomy.
Our standard fee for TTA surgery is $3000. This fee includes a number of additional services that improve recovery, ensure long term success and also help us to gather long term follow up information for a study on the effects of TTA in the dog. This fee includes: