Tibial-plateau-leveling osteotomy
TPLO ( Tibial Plateau Leveling Osteotomy for abbreviation ) is a surgical procedure in animal surgery, be treated with the torn cruciate ligaments in dogs since 1998. The procedure was developed in the 1990s by the American scientists Barkley and Theresa Devine Slocum. In the TPLO plates is patented by a round cut, the tibia ( shin bone) cut through and through, specially assigned, screwed again in a changed position. The aim is to avoid the changing biomechanics the feed, which is normally captured by the anterior cruciate ligament.
- 5.1 Accompanying measures
- 8.1 Notes and references
- 8.2 Further Reading
Bones of the hind limbs
Upper and lower legs are joined by the knee joint. It 's not how often assumed wrongly the ankle, the most important joint for the movement of the dog. The decisive factor for the thrust of the hindquarters is the angulation of the knee joint. Here angle of 130 ° resulting in working dogs and up to 159 ° for greyhounds. Particularly steep Asked breeds are prone to jumping out of the kneecap, called a patellar dislocation. The knee joint is so important because it initiates, in collaboration with the hip and ankle, the movement of the leg and thus of the entire animal. It must therefore be designed to be particularly strong and should be angled as low as possible. From this joint from the strongest impacts on the entire body are transmitted. To comply with the direction to make the front for a kneecap and on the other hand, the bands, which include the cruciate ligaments. It also avoids excessive stretching of the limb is prevented. The lower leg, which is followed by the knee joint formed by two bones - the tibia (tibia ) and the fibula ( fibula ). The latter is rotated by 90 °, behind the tibia. The shin supporting the entire body weight.
If you, in the normal position of the dog, from the hip joint of a Lot, as it represents the line of gravity of the dog that crosses the lower leg once. The knee joint is thus present the line of gravity and the ankle behind it.
Tear of the anterior cruciate ligament in the dog and its consequences
The cruciate ligaments in the knee of the dog have to fulfill an important function stability. It should be noted that this feature is even more important due to the angulation of the hind leg, as is the case with the man who has the most important joints in the line of gravity. Both cruciate ligaments are strongly developed in the dog.
Unlike in humans, the anterior cruciate ligament tears in dogs often without a previous trauma ( such as an accident ). In most cases, the tape is misloaded chronic, which can have several reasons. According to current knowledge, a major cause is too straight angulation of the articular surface of the lower leg - the " tibial plateau ". Here at each step is weighed on the cruciate ligaments to a strong forward thrust ( cranial tibial thrust ). The steeper the joint surface is now available, the greater the forward thrust. One can compare this situation to an inclined plane, wherein the object which is drawn by the downward force by a tape ( similar to the function of the cruciate ligament ) protected from sliding down. It creates small tears in the ligament, the increase until eventually sufficient to allow a slightly wrong move to tear the tape. One speaks in this context of a minor trauma. Here are typical scenarios agitated ball games, playing with other animals, hunting on uneven terrain or slipping on smooth surfaces. Affected by such a torn ligament so are almost all races and all ages. However, larger breeds have a higher tendency to crack because of the forward thrust is also increased by the greater weight.
Since with a torn ACL, the supporting effect of the tape is removed, there is an instability in the knee that has far-reaching consequences. The knee joint is, through the lack of leadership, now exposed to a strong friction, which causes pain and in due course to irreparable arthritis in the joint, and cartilage damage. A further consequence of the damage of the joint is that it can pass through the misalignment and stress in a change in the entire spine and can alter the structure of the bones and muscles beyond.
Symptoms
After such minor trauma has occurred, the animals usually moderately lame. This means that the gait is disturbed and no longer use the dogs the affected limb steadily. Often the dogs walk again " a ", which eventually leads to the dog owner the problem attaches no great importance, and proceeds from a sprain. With increasing duration of the problem the animals have great difficulty getting up and limping heavily after.
While a complete ligament tear can be diagnosed relatively easily and without special effort, it is often very difficult for a teaser of the band to make a correct diagnosis. One method to which the attending veterinarian often employs is the so -called drawer test. For him, the upper and lower legs are shifted against each other. This can very well find the instability in the joint.
In the further course of the disease, the meniscus is heavily loaded, leading to a crack, or for turning thereof. You can hear the flipping of the meniscus when listening very carefully. This phenomenon is called the meniscus click.
Tibial Plateau Leveling Osteotomy - TPLO
The veterinarians who wish to perform a TPLO, are trained by Slocum, even in some training. Not the only reason, but also because of the high costs for the diagnosis or arthroscopy and surgery itself, is a justified, in contrast to conventional methods, a relatively high price. This moves an average of 1200-1400 euros, although the images in magnetic resonance imaging, as well as the follow-up, are not included in the calculation.
The idea of TPLO
So far, about 50 different methods to supply a rupture of the anterior cruciate ligament have been developed. Most surgical techniques are derived from the human anatomy and thus achieve poor results, the predictions at small and light animals are relatively good. In dogs that have a mass greater than 30 kg, the prospects of success are poor. The main reason for this is that in small dogs much lower forces acting on the joint. Also in sport and service dogs of the success of " old" surgical techniques is not very big to be expected.
Because of the more or less successful was poor by American scientists Barkley and Theresa Devine Slocum developed a method, which differs significantly from all previous - the TPLO ( Tibial Plateau Leveling Osteotomy ). The idea is that you feed the acting on the knee joint, prevents, by so changing the position of the articular surface of the lower leg that she cancels all forces. The repair of the anterior cruciate ligament and thus opening the knee joint should be largely avoided. If the meniscus, however, already badly damaged, the knee still needs to be opened and the ruined remains of the meniscus affected part be removed. According to recent findings, however, tried by an arthroscopy to check if opening the knee is absolutely necessary.
Since the angular position is responsible for the feeding, in a complex process of the existing angle of the tibial plateau is determined and theoretically optimized. For this, different X-ray pictures are taken and set the angle needed. Patients who undergo surgery with a conventional method, but must expect a progression of arthritic changes. In contrast, the TPLO knee osteoarthritis remains either entirely free or there is only a 1 degree osteoarthritis ( maximum of 3 degrees ).
The surgical technique of the TPLO
Using a patented circular saw will cut through the tibia of the affected limb. At the interface of the upper portion of the tibia is rotated so that the previously calculated optimal biomechanical angle is achieved. If this is reached, the separate bones with one specifically designed for that purpose six-hole plate, screwed again. The process is aligned in principle to the supply of a bone fracture. An important aspect here is that the fibula is intact, because during the healing phase of the tibia now busy much of the vertical load on the fibula. If the fibula is damaged this imperative a previous supply.
Postoperative Care
Patients who were operated on after a TPLO must be up to 12 weeks held firmly to ensure good healing of the bone. However, the operated dogs are usually relatively quickly back on his feet and use the operated leg well. It is usually to be expected with a lead of about four weeks compared to conventional methods.
Immediately following the surgery painkillers and antibiotics. The animals are to move and the leg as possible after 2 weeks burden well, so that a muscle can slowly build up again. In essence, one can speak of two phases during the healing process. One healing phase, which lasts 6-12 weeks and during to the altered biomechanics and arthritic processes in the knee heal. As a result, one speaks of a rehabilitation phase in which the patient must learn to use the leg again active, so that the muscles in the leg is strengthened again.
Accompanying measures
Throughout the healing process following should be noted:
- The dog may not be overweight, otherwise the load on the operated knee would be too great.
- The dog is always to lead especially at the beginning of the line.
- The raging, stick game that lawn at the garden fence, playing in deep snow, mountain tours, jumps or play with other dogs is strictly prohibited and to absolutely avoid.
- Feed additive, homeopathic remedies, acupuncture or magnetic mats can be supportive, the measures referred to but not replace it.
It is also advisable to consult a veterinary physiotherapist. This can then take specially tailored to the needs of the dog supportive measures, which usually leads to accelerated healing. Such measures are, massages, electrotherapy, exercise training with equipment or the underwater treadmill. After about eight weeks, the patient should increase the load slowly, with the emphasis must be on "slow" down here.
Long-term success of the TPLO
Detailed studies on the long-term results of the TPLO are not available. In a study of 101 dogs TPLO - operated group showed no lameness, the rest at about 50 % of the dogs only a mild one, in contrast to the other according to surgical methods treated group. The pain of the animals were reduced on average.
Dangers and problems
The TPLO is a massive intervention in the biomechanics, which may easily lead to complications. In 2006, a long-term study of TPLO patients was published, in which around 700 animals were observed over a period of 30 months. The complication here was 18.8 percent. The issues covered in the study were for example:
- Increased tendency to hemorrhage (bleeding)
- Swelling at the spot where the first cut has been made
- Premature removal of the threads by the patient himself, for example by licking of the wound. It is essential to make sure that this is omitted, as this may occur through the mechanical action of the tongue to the wound, germs into the wound and thus a serious infection can occur.
- Fracture of the shin bump ( tibial tuberosity )
- Swelling of the patellar ligament: Long-term studies show that it comes after a TPLO to inflammation ( desmitis ) and swelling of the patellar ligament. But to what extent this leads to restrictions of movement or lameness, has not been elucidated.
- Problems with the implant
User reviews have shown that there is a temporary numbness in the operated limb (even by the association or surgery) can always come back. This manifests itself in a " Überköten " the paw. This means that the dog is on his back paws and apparently is not able to control the paw correctly, so as to correct its course.
Another problem, which is led mainly by veterinarians, the newer TTA prefer ( Tibial Tuberosity Advancement ), are for their accuracy but hardly obtain materials, is the danger of the operation to be irreparably damaged while major vessels and nerves, which may eventually lead to a complete loss of limb.