Juvenile pubic symphysiodesis associated with pectineus myectomy for treatment of hip dysplasia in dog

Background: Hip dysplasia (HD) is the most common non-traumatic orthopedic disease in large breed dogs. Treatment is chosen according to the severity of the condition, the age of the dog and the involvement of osteoarthritis (OA). For puppies up to 20-weeks-old, surgical treatment by the juvenile pubic symphysiodesis (JPS) technique can be performed. This procedure promotes the ventrolateral rotation of the acetabulum over the femoral head, which improves hip joint congruence and stability. The objective of this study is to report the case of a young dog with HD treated with JPS and pectineus myectomy. Clinical and radiographic outcomes were assessed for up to one year after surgery.Case: A 17-week-old Saint Bernard puppy was attended at the University Veterinary Hospital showing abnormal weight bearing and lameness in pelvic limbs, without history of previous trauma. On orthopedic examination, there was a marked hypotrophy of the pelvic limb muscles, severe pain and laxity in the hip joints, and positive feature in the Ortolani test. The hip joint subluxation angle (SA) and reduction angle (RA) were measured. A radiographic study was carried out to evaluate the hip joints and measure the Norberg angle (NA), distraction index (DI), acetabular angle (AA) and dorsal acetabular rim angle (DARA). The 20-week-old dog underwent surgical treatment by JPS technique. A ventral surgical approach to the pubis was performed and the pubic symphysis was cauterized with electrocautery. Partial pectineus myectomy technique was also performed. Drug therapy and restriction of physical activities were indicated in the early postoperative. The dog was evaluated by clinical and radiographic examinations at 4 months and 1 year after the surgical procedure. In the reassessment after 4 months of surgical treatment, the patient showed improvement in clinical signs, with mild lameness and absence of painful sensitivity in the movement of the hip joints. Radiographically, hip joint incongruity was observed, but with progressive improvement in the values of the measured variables. In the clinical examination 1 year after the procedure, the dog showed satisfactory weight bearing with slight lameness in pelvic limbs in the running gait. There was improvement in the thigh muscles and no painful signs were observed in the hip joints, but a positive result was detected in the Ortolani test. In the radiographic examination, bilateral articular incongruity was still observed, however, there was a mild improvement in the coverage of the acetabulum over the femoral head. The measured angles and indices showed favorable results regarding the recovery of hip joint stability and proper development.Discussion: Studies evaluating the JPS technique for the treatment of HD have shown to be a relatively simple and effective procedure, which allows altering the acetabular coverage, reducing the development of HD and the progression of OA. The need for an early diagnosis of this condition is essential, so that the JPS technique can be used in young dogs and offer effective results. In the present report, in the late postoperative period, the dog showed improvement in clinical signs, with favorable weight bearing and ambulation in pelvic limbs, recovery of limb muscles, absence of pain in the hip joints and decrease in RA and SA. Radiographically, the reduction in joint subluxation, improvement in acetabular coverage over femoral heads, increase in NA and AA, reduction in DI and DARA are evidence of the favorable outcome of ventrolateral rotation of the acetabulum after surgical treatment. The surgical technique used was effective, which enabled the dog to recover the functional use of the pelvic limbs and improve the quality of life.Keywords: hip dysplasia, juvenile pubic symphysiodesis, hip joint, osteoarthritis, dog.Título: Sinfisiodese púbica juvenil associada à miectomia do pectíneopara tratamento de displasia coxofemoral em cãoDescritores: displasia coxofemoral, sinfisiodese púbica juvenil, coxofemoral, osteoartrite

Clinical comparison between two stabilization methods in distal tibial angular deviation corrected by the CORA method

Background: Angular deformity is characterized by the deviation of part of the bone that can occur in three different planes, frontal, sagittal and transverse. Trauma on physeal plates is the most common cause of angular deviations of the limbs in dogs. Currently the CORA (Center of Rotation of Angulation) methodology is the best way to evaluate and surgically correct these deformities. The objective of this study is to describe the surgical procedures performed to treat the uniapical valgus deviation affecting both tibial bones in a dog, comparing the outcomes of hybrid external skeletal fixator used in the right pelvic limb in relation to the locking plate used in the left pelvic limb.Case: A 10-month old Border Collie dog was attended at the University Veterinary Hospital with history of lameness and deviation of both pelvic limbs. In the orthopedic examination, it was possible to identify bilateral valgus deviation in the region of the tibio-tarsal joints and moderate lameness, with absence of pain or joint crepitation. Radiographic examination showed that the deformity was only uniapical in the frontal plane, affecting both tibial bones of the dog. Signs of osteoarthrosis were not observed and the preoperative examinations were within the normal limits for the species. The deformities were corrected in two surgical times starting with the procedure in the right tibia, which appeared to be clinically worse. Due to the fact that it was a bilateral affection and there was not a healthy pelvic limb to obtain the normal angles values of this dog, for planning according to the CORA methodology, the values of the tibial mechanical angles for dogs of similar size were taken from the literature. For surgical correction of the right tibia, a closed wedge osteotomy was performed following the second rule of Paley, with bone stabilization using type IB hybrid external skeletal fixator (ESF). The radiographic follow-up was done every 30 days postoperatively, however at 60 days the dog presented with severe lameness and the ESF had to be removed due to the breaking of one of the wires that composed the ring of the hybrid system. The limb continued to be treated by external bandages and total bone healing occurred at 210 days after surgery. Only after the complete recovery of the right limb, the left pelvic limb was operated and was also corrected by closed wedge osteotomy from the second Paley's rule. However, the bone stabilization was achieved with the use of a T-shaped locking plate. Radiographic follow-up was performed every 30 days postoperatively and at 60 days the osteotomy gap was already consolidated and the dog showed good weight bearing in the pelvic limbs without signs of lameness or pain.Discussion: Currently, it is indicated that bone deformities in small animals should be corrected using the CORA methodology. The hybrid ESF is one of the most commonly used fixation systems for bone stabilization after corrective osteotomies due to great versatility, however, the reported complication rates are relatively high. The locking plates with special shapes, such as the "T" plate used in this study, provide the stable fixation of osteotomies with limited bone stock, as they allow the introduction of larger number of screws per area. Thus, this latter type of implant becomes advantageous for the correction of bone deformities close to the joints. It is concluded that CORA methodology is really effective in the planning of corrective surgeries of angular deviations in dogs. In this case report, the resulting tibial angles after the surgical corrections were within the normal range for healthy dogs of similar size. However, the use of locking plate provided better results with early bone healing and fewer complications than the type IB hybrid ESF

Technique of Tibial Tuberosity Transposition and Advancement (TTTA) With Use of TTA-Maquet Cage-Only in Dog

Background: The most common conditions that compromise the stifle joint in dogs are medial patellar luxation (MPL) and cranial cruciate ligament (CCL) rupture. Surgical procedures are usually indicated for the treatment of these diseases. One ordinary technique for the treatment of MPL is the tibial tuberosity transposition, and one prominent technique for CCL rupture is the tibial tuberosity advancement. These techniques can be associated in one surgical procedure called tibial tuberosity transposition and advancement (TTTA) for the simultaneous treatment of both stifle diseases. The aim of this study is to report the surgical treatment of a dog with MPL and CCL rupture affecting the same joint by the TTTA technique with the use of a TTA-Maquet cage-only.Case: A 3-year-old Pitbull dog weighing 39 kg was attended at Veterinary Hospital with a history of marked lameness in the left pelvic limb. The orthopedic examination showed positive results for cranial drawer motion and tibial compression tests, and a complete CCL rupture was diagnosed. The presence of patellar luxation was evaluated by manual pressure on the patella, and grade 3 of MPL was diagnosed. Both conditions were affecting the same stifle joint. In addition, survey radiographs of the affected joint were performed. Surgical treatment was indicated by the TTTA technique. Radiographic measurements were taken to calculate the cranial tibial tuberosity advancement by the tibial plateau and the common tangent methods, and a titanium TTA-Maquet cage-only of 10.5 x 20.0 mm was selected. Linear osteotomy was performed on the tibial tuberosity with the aid of an oscillating saw, based on the Maquet hole technique. The tibial tuberosity was carefully displaced cranially and the cage was inserted at the site of osteotomy. The cage ears were molded on the tibial surface and fixed with 2.4 mm self-tapping cortical screws. At the moment of the cage attachment to the tibial tuberosity, orthopedic washers of 2 mm wide were placed between the cranial ears of the cage and the tibial tuberosity, thus promoting a lateral transposition of the tibial tuberosity. The patient was maintained in the early postoperative period with Robert Jones bandage, and with antibiotic, analgesic and anti-inflammatory drugs. On the second day after the procedure partial limb support with presence of mild lameness was observed. At three months postoperatively, the animal had no claudication and MPL was corrected. The radiographic examination showed the proper process of bone repair at the osteotomy site. In the clinical evaluation performed at one year after surgery the patient was in good condition without lameness and with proper limb support and muscular gain.Discussion: The studies that evaluated the association of tibial tuberosity transposition and tibial tuberosity advancement techniques (TTTA) for the simultaneous treatment of MPL and CCL rupture demonstrated that this is a viable and effective procedure. In this report, the accomplishment of tibial osteotomy based on the Maquet hole and the advancement of the tibial tuberosity with the TTA-Maquet cage-only allowed the dynamic stabilization of the CCL deficient stifle and the early use of the affected limb. In addition, the TTTA technique proved to be effective for the correction of grade 3 of MPL in a large dog, allowing adequate recovery of the limb function without complications during a one year evaluation period

Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs

ABSTRACT Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate–PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods