Various methods of repair of a cruciate ligament in dogs and cats have been tried over the years and this really means there is no perfect way to fix the rupture of this ligament in animals. One of the newer techniques has been a method called a Tibial Tuberosity Advancement or TTA. This has been around for close to a decade now and works by redirecting the force generated by the large quadriceps muscles to compensate for the failed cruciate ligament. This muscle is the one at the front of the hind leg and works through the knee cap and patellar tendon which attaches to the top of the tibia at the tibial tuberosity. The bone is cut in what is called an osteotomy and the piece of bone released is moved forward a few millimetres and traditionally fixed in place with a metal implant, plates and screws. Although very successful, the TTA method has been associated with a high rate of complications and implant failure.
The Modified Maquet Procedure (MMP) uses a very high tech titanium foam wedge developed for human use to fill the gap of the osteotomy. This foam, called Orthofoam, promotes rapid bone ingrowth and healing; the wedge is actually incorporated into bone. This means a reduced period of convalescence and minimal pain when compared to other procedures. However, the main advantage over traditional TTA techniques is the much lower rate of complications and, when these do happen, they tend to be minor without the need for revision surgeries
The technique has been developed in Europe over the past few years and roughly ten thousand cases have been done to validate and perfect the technique.
We have started to use this method at Blair Street Veterinary Hospital and have been impressed with the results. It offers a very safe and cost effective way to treat rupture of the cranial cruciate ligament in medium and smaller dogs and is a valuable addition to the range of surgeries which we can do her at the hospital. It is a great way to bring advanced techniques to more patients and we would recommend it to our clients.
Securos X-gen PROS/BOSS Orthofiber Cruciate Surgery
The Securos X-gen CCR system is a new system for fixing a ruptured cruciate ligament in medium to large breed dogs. It uses a special type of braided artificial fibre called Orthofiber, which is extremely strong and durable. This fibre is carefully placed at isometric points on the outside of the stifle (knee) joint, which mimics the action of the cruciate ligament to stabilise the knee joint but also allows full movement of the joint. Bone tunnels are drilled through the bottom of the femur and top tibia to pass the suture through. These tunnels are strengthened by special PROS implants. The PROS implant is a hollow titanium screw with a smooth, curved exit to prevent wear and fraying that would otherwise lead to breakdown of the Orthofiber which passes through the PROS implant. The PROS implants are also raised up 1.5mm so that the fibre that bridges between the two PROS implants causes less crushing and friction injury to sensitive underlying tissues, which includes the sensitive joint capsule. The Orthofiber is anchored on the inside (medial) side of the knee by titanium BOSS button implants which have a carefully rounded and smooth surface to minimise wear on the fibre.
The Orthofiber is looped through the BOSS buttons on the medial side and threaded back through the bone tunnels and out of the PROS bone tunnel implants.
The fibre is tightened using a special tensioning device to the correct tension which provides optimal stabilisation of the knee yet still allows full range of movement. A titanium crimping tube is placed over the two ends of the Orthofiber and a crimping tool is used to crimp (crush it closed) securing it. Use of a crimp tube avoids the risk of the Orthofiber snapping where it is knotted, if a surgical knot is tied instead of crimping. The result is a doubled Orthofiber prosthesis that is extremely strong, yet durable.
Benefits Over Lateral Suture Stabilisation Technique
Isometrically placed Orthofiber allows much more normal movement of the knee after surgery.
Isometric fixation points reduce the outward turning of a dog's leg often seen with De Angelis.
Much more accurate and optimal tension to best stabilise the knee.
Less loosening of the Orthofiber because it is not crushing and cutting through underlying tissue.
Much longer lasting Orthofiber that, as yet, has never broken.
Benefits Over Other Techniques
Stabilises the knee where as TTA (Tibial Tuberosity Advancement) or a TPLO (Tibial Plateau Levelling Operation) does not thus reducing damage to the menisci.
Less confinement required during recovery and healing (2 weeks compared to 8-10 weeks for TTA).
No catastrophic breakdown (the leg bone may fracture after a TTA surgery).
We have been extremely impressed with the results seen on dogs treated using this system. They have a much faster return to function and minimal loss of muscle mass on the affected leg. We believe this to be a winner all round and represents the best value for money currently in cruciate repair treatments.
The Securos CCR cruciate repair system is very similar to the Tightrope repair method. These methods in the studies done so far have achieved the best outcomes coupled with minimal complications and fastest recovery from surgery.
REF:- Vet Surg. 2013 Apr;42(3):329-34. doi: 10.1111/j.1532-950X.2013.12001.x. Epub 2013 Feb 21.