Tibial Tuberosity Advancement (TTA) is an orthopedic procedure to repair deficient cranial cruciate ligaments in dogs. It has also been used in cats. This procedure was developed by Dr. Slobodan Tepic and Professor Pierre Montavon at the School of Veterinary Medicine, University of Zurich, in Zurich, Switzerland beginning in the late 1990s.
Dr. Slobodan Tepic later founded KYON, a leading provider of veterinary orthopaedic implants, in 1999. Kyon became the first veterinary orthopedic implant company offering this procedure to veterinarians.
The cranial cruciate ligament (CrCL) in dogs, provides the same function as the anterior cruciate ligament in humans. It stabilizes the knee joint, called the stifle joint in quadrupeds, and limits the tibia from sliding forward in relation to the femur. It is attached to the cranial (anterior) medial side of the interdylar notch of the tibia at one end and the caudal (posterior) side of the lateral femoral condyle at the other end. It also helps to prevent the stifle (knee) joint from over-extending or rotating.
Trauma to the equivalent ligament in humans is common, and damage most frequently occurs during some form of sporting activity (including football, rugby and golf). The nature of the injury is very different in dogs. Rather than the ligament suddenly breaking due to excessive trauma, it usually degenerates slowly over time, rather like a fraying rope. This important difference is the primary reason why the treatment options recommended for cruciate ligament injury in dogs are so different from the treatment options recommended for humans.
In the vast majority of dogs, the cranial cruciate ligament (CrCL) ruptures as a result of long-term degeneration, whereby the fibres within the ligament weaken over time. The precise cause of this is not known, but genetic factors are probably most important, with certain breeds being predisposed (including Labradors, Rottweilers, Boxers, West Highland White Terriers and Newfoundlands). Supporting evidence for a genetic cause was primarily obtained by assessment of family lines, coupled with the knowledge that many animals will rupture the CrCL in both knees, often relatively early in life. Other factors such as obesity, individual conformation, hormonal imbalance and certain inflammatory conditions of the joint may also play a role. Uncorrected CrCL deficiencies have been associated with meniscal damage and degenerative joint diseases such as osteoarthritis.
TTA is a surgical procedure designed to correct CrCL deficient stifles. The objective of the TTA is to advance the tibial tuberosity, which changes the angle of the patellar ligament to neutralize the tibiofemoral shear force during weight bearing. A microsaggital saw is used to cut the Tibial Tuberosity off then a special titanium cage is used to advance the tibial tuberosity. A titanium plate is used to hold the tibial tuberosity in position.By neutralizing the shear forces in the stifle caused by a ruptured or weakened CrCL, the joint becomes more stable without compromising joint congruency.
TTA appears to be a less invasive procedure than some other techniques for stabilizing the deficient cranial cruciate ligament such as TPLO (Tibial Plateau Leveling Osteotomy) and TWO (Tibial Wedge Osteotomy), as TTA does not disrupt the primary loading axis of the tibia.
Since KYON first developed the TTA procedure, they have pioneered a new less invasive version of the procedure known as TTA-II. This new TTA procedure delivers the same TTA outcomes with less trauma, fewer implants, a simplified technique and at a reduced cost.
Recently, TR BioSurgical has developed a bioscaffold to be used for veterinary osteotomies as a substitute for autologous cancellous bone grafting.
In 2012 TTA RAPID was introduced by the German manufacturer RITA LEIBINGER Medical GmbH & Co. KG in cooperation with the University of Ghent, Belgium. The TTA RAPID implant is a biocompatible sponge-construction which combines a wedge-cage with a plate on the top. In this way there is only one implant needed for the whole TTA surgery. It is called "rapid" because the implantation is very quick, easy to learn and offers a high stability. The surgery is based on the Maquet-Hole-Technique.
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee is vulnerable to injury and to the development of osteoarthritis.
In human anatomy, a hamstring is any one of the three posterior thigh muscles in between the hip and the knee. The hamstrings are quite susceptible to injury.
The tibia, also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates, and it connects the knee with the ankle bones. The tibia is found on the medial side of the leg next to the fibula and closer to the median plane or centre-line. The tibia is connected to the fibula by the interosseous membrane of the leg, forming a type of fibrous joint called a syndesmosis with very little movement. The tibia is named for the flute tibia. It is the second largest bone in the human body next to the femur. The leg bones are the strongest long bones as they support the rest of the body.
An osteotomy is a surgical operation whereby a bone is cut to shorten or lengthen it or to change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture. It is also used to correct a coxa vara, genu valgum, and genu varum. The operation is done under a general anaesthetic.
The posterior cruciate ligament (PCL) is a ligament in each knee of humans and various other animals. It works as a counterpart to the anterior cruciate ligament (ACL). It connects the posterior intercondylar area of the tibia to the medial condyle of the femur. This configuration allows the PCL to resist forces pushing the tibia posteriorly relative to the femur.
The anterior cruciate ligament (ACL) is one of a pair of cruciate ligaments in the human knee. The 2 ligaments are also called cruciform ligaments, as they are arranged in a crossed formation. In the quadruped stifle joint, based on its anatomical position, it is also referred to as the cranial cruciate ligament. The term cruciate translates to cross. This name is fitting because the ACL crosses the posterior cruciate ligament to form an “X”. It is composed of strong fibrous material and assists in controlling excessive motion. This is done by limiting mobility of the joint. The anterior cruciate ligament is one of the four main ligaments of the knee, providing 85% of the restraining force to anterior tibial displacement at 30 degrees and 90 degrees of knee flexion. The ACL is the most injured ligament of the four located in the knee.
The Lachman test is a clinical test used to diagnose injury of the anterior cruciate ligament (ACL). It is recognized as reliable, sensitive, and usually superior to the anterior drawer test.
A luxating patella, sometimes called a trick knee, is a condition in which the patella, or kneecap, dislocates or moves out of its normal location.
Pentosan polysulfate (PPS) is a medication used for interstitial cystitis and osteoarthritis. It is a semi-synthetic polysulfated xylan.
The drawer test is used in the initial clinical assessment of suspected rupture of the cruciate ligaments in the knee. The patient should be supine with the hips flexed to 45 degrees, the knees flexed to 90 degrees and the feet flat on table. The examiner positions himself by sitting on the examination table in front of the involved knee and grasping the tibia just below the joint line of the knee. The thumbs are placed along the joint line on either side of the patellar tendon. The tibia is then drawn forward anteriorly. An increased amount of anterior tibial translation compared with the opposite limb or lack of a firm end-point may indicate either a sprain of the anteromedial bundle or complete tear of the ACL. If the tibia pulls forward or backward more than normal, the test is considered positive. Excessive displacement of the tibia anteriorly suggests that the ACL is injured, whereas excessive posterior displacement of the tibia may indicate injury of the posterior cruciate ligament.
Dog anatomy comprises the anatomical studies of the visible parts of the body of a canine. Details of structures vary tremendously from breed to breed, more than in any other animal species, wild or domesticated, as dogs are highly variable in height and weight. The smallest known adult dog was a Yorkshire Terrier that stood only 6.3 cm (2.5 in) at the shoulder, 9.5 cm (3.7 in) in length along the head and body, and weighed only 113 grams (4.0 oz). The largest known adult dog was an English Mastiff which weighed 155.6 kg (343 lb) and was 250 cm (98 in) from the snout to the tail. The tallest known adult dog is a Great Dane that stands 106.7 cm (42.0 in) at the shoulder.
The stifle joint is a complex joint in the hind limbs of quadruped mammals such as the sheep, horse or dog. It is the equivalent of the human knee and is often the largest synovial joint in the animal's body. The stifle joint joins three bones: the femur, patella, and tibia. The joint consists of three smaller ones: the femoropatellar joint, medial femorotibial joint, and lateral femorotibial joint.
Cruciate ligaments are pairs of ligaments arranged like a letter X. They occur in several joints of the body, such as the knee joint and the atlanto-axial joint. In a fashion similar to the cords in a toy Jacob's ladder, the crossed ligaments stabilize the joint while allowing a very large range of motion.
The patellar ligament is the distal portion of the common tendon of the quadriceps femoris, which is continued from the patella to the tibial tuberosity. It is also sometimes called the patellar tendon as it is a continuation of the quadriceps tendon.
TPLO, or tibial-plateau-leveling osteotomy, is a surgery performed on dogs to stabilize the stifle joint after ruptures of the cranial cruciate ligament.
The unhappy triad, also known as a blown knee among other names, is an injury to the anterior cruciate ligament, medial collateral ligament, and meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, "combined anterior cruciate and medial collateral ligament disruptions that were incurred during athletic endeavors" always present with concomitant medial meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.
Unicompartmental knee arthroplasty (UKA) is a surgical procedure used to relieve arthritis in one of the knee compartments in which the damaged parts of the knee are replaced. UKA surgery may reduce post-operative pain and have a shorter recovery period than a total knee replacement procedure, particularly in people over 75 years of age. Moreover, UKAs may require a smaller incision, less tissue damage, and faster recovery times.
The triple tibial osteotomy is a surgical procedure used to treat dogs that have completely or partially ruptured the cranial cruciate ligament in one or both of their stifles. The cranial cruciate ligament connects the femur with the tibia, which functions to stabilise the canine stifle joint from the forces put on it during exercise and weight bearing.
Tightrope CCL is a veterinary orthopedic surgical method developed to provide a minimally invasive procedure for extracapsular stabilization of the canine cranial cruciate ligament-deficient stifle joint. The cranial cruciate ligament (CrCL) stabilizes the dog knee much like the anterior cruciate ligament (ACL) does in humans.
Simitri Stable in Stride is a three part modular surgical implant used during surgery performed on dogs to stabilize the stifle joint (knee) after rupture of the cranial cruciate ligament (CrCL) which is analogous to the anterior cruciate ligament (ACL) in humans.
4. Boudrieau RJ: Tibial Plateau Leveling Osteotomy or Tibial Tuberosity Advancement? Vet Surg 38:1-22, 2009
5. Kim SE, Pozzi A, Banks SA, et al.: Effect of Tibial Tuberosity Advancement on Femorotibial Contact Mechanics and Stifle Kinematics. Vet Surg 38:33-39, 2009