Tibial plateau leveling osteotomy in dogs: an ex vivo comparative study of knee's surrounding structures protection methods

Background: Cranial cruciate ligament failure is one of the leading causes of pelvic limb lameness in dogs and one of the most recommended treatments is tibial plateau leveling osteotomy (TPLO) surgery. However, this procedure may lead to some complications as fractures of the fibula, laceration in varying degrees of the popliteal vasculature and its branches, neuropraxia, neurotmeses, among others. The goals of this study were to compare the effectiveness of 8 methods used during TPLO, to prevent damage to the cranial tibial artery, fibula, tibial and fibular nerve (surgical compresses, specific surgical retractors I and II and an osteotomy technique variation). Materials, Methods & Results: A total of 40 canine cadavers weighing 25.9 ± 3.7 kg were submitted to TPLO. Animals were previously prepared with 1: 4 barium red latex solution, to provide radiopacity of arteries surrounding the knee (n = 80). TPLO was performed using 8 methods to protect the cranial tibial artery, fibula, and tibial and fibular nerves. Each method was used in one of the knees of 5 animals. The contralateral knee was maintained as a control (without protection). The knees were radiographed in orthogonal projections before and after the osteotomies and then anatomically dissected. The evaluated structures were photographed, and the images sent to four blind evaluators (visual macroscopy) to classify the possible injuries. The highest incidence of injuries was identified when protection methods were used. However, this difference was not significant (P > 0.05). No significant differences regarding efficacy were found between all 8 protection methods. Discussion: In this study, the total incidence of injuries following TPLO was 20% was much higher than that presented in the literature which indicates when considering only intraoperative injuries. The dogs cadavers tissue resistance and stiffened latex may have predisposed the osteotomy injury, as soft tissues with greater flexibility are less susceptible to trauma caused by the oscillatory saw. When compared to others cadaveric studies that also evaluated the efficacy of surgical dressings to protect the cranial tibial artery, during TPLO, we also find a higher incidence of damage. Maybe the limb's position was responsible for this difference, once in the after mentioned researches the limb was positioned suspended to simulate a dorsal decubitus position and we choose the limb position with the lateral face resting on the surface of the operating table, and this may have provided extra pressure from the structures towards the osteotomy saw, increasing the occurrence of those damages. Although the present study did not reveal a significant difference for the use of protection methods, we believe that the dimensions of the compresses used herein may have contributed to a higher incidence of injuries. They probably increased the tissue trauma needed for their allocation and led to a lower positioning accuracy for the isolation of these structures. Maybe for the same reason, the specific type II surgical retractor was the only shield that, observationally, did not increase the occurrence of injuries, once less dissection was required to allocate it. The difference in geometric dimensions between the retractors may justify the superiority of the retractor II, since it allows a more careful and apparently less traumatic allocation. Performing TPLO without adopting these protection methods did not lead to a higher risk of injury to the cranial tibial artery, fibula, and tibial and fibular nerves.

Application of a meshed skin graft in the surgical bed immediately after resection of neurofibrosarcoma in the distal limb region of a dog

Background: Malignant peripheral nerve sheath tumors are neurogenic neoplasms that originate from cells that surroundthe axons of peripheral nerves. Surgery is the treatment of choice for peripheral nerve sheath tumors. They have a betterprognosis when the lesion is in the extremity of a limb and the surgeon leaves wide peripheral margins after resection.However, this procedure makes local treatment a challenge due to difficult wound healing in this region. This report describes a successful case involving the use of a meshed skin graft immediately after resection of a neurofibrosarcoma inthe distal region of the radius bone of a dog.Case: A 6-year-old Boxer bitch weighing 40 kg was admitted with a history of a round, firm, non-ulcerated skin noduleattached to the lateral side of the distal region of the right radius bone, which had been present for about 40 days. Fineneedle aspiration cytology of the lesion showed the presence of mesenchymal cells, suggesting a sarcoma. Thus, the decision was made for an incisional biopsy to confirm the diagnosis and for the preparation of a subdermal pattern tubular flapfor subsequent rotation and transposition to close the wound that would be formed after the complete removal of the lesion.After the 7th postoperative day, the diagnosis of low-grade neurofibrosarcoma was confirmed and due to the presence ofnecrotic onset in the middle portion of the tubular flap, further surgical intervention was scheduled for the resection of thetube flap, en bloc removal of the neoplastic lesion with peripheral margins of 2 cm, and wound closure with a free skingraft. A mesh skin graft was made with a portion of the right flank skin. The mesh graft was carefully implanted on therecipient bed using simple interrupted sutures with a 3-0 non-absorbable monofilament suture material. A dressing madewith water-based sterile lubricating solution and...

Application of a meshed skin graft in the surgical bed immediately after resection of neurofibrosarcoma in the distal limb region of a dog

Background: Malignant peripheral nerve sheath tumors are neurogenic neoplasms that originate from cells that surroundthe axons of peripheral nerves. Surgery is the treatment of choice for peripheral nerve sheath tumors. They have a betterprognosis when the lesion is in the extremity of a limb and the surgeon leaves wide peripheral margins after resection.However, this procedure makes local treatment a challenge due to difficult wound healing in this region. This report describes a successful case involving the use of a meshed skin graft immediately after resection of a neurofibrosarcoma inthe distal region of the radius bone of a dog.Case: A 6-year-old Boxer bitch weighing 40 kg was admitted with a history of a round, firm, non-ulcerated skin noduleattached to the lateral side of the distal region of the right radius bone, which had been present for about 40 days. Fineneedle aspiration cytology of the lesion showed the presence of mesenchymal cells, suggesting a sarcoma. Thus, the decision was made for an incisional biopsy to confirm the diagnosis and for the preparation of a subdermal pattern tubular flapfor subsequent rotation and transposition to close the wound that would be formed after the complete removal of the lesion.After the 7th postoperative day, the diagnosis of low-grade neurofibrosarcoma was confirmed and due to the presence ofnecrotic onset in the middle portion of the tubular flap, further surgical intervention was scheduled for the resection of thetube flap, en bloc removal of the neoplastic lesion with peripheral margins of 2 cm, and wound closure with a free skingraft. A mesh skin graft was made with a portion of the right flank skin. The mesh graft was carefully implanted on therecipient bed using simple interrupted sutures with a 3-0 non-absorbable monofilament suture material. A dressing madewith water-based sterile lubricating solution and...(AU)

Pantarsal arthrodesis with a locking plate as treatment for reabsorptive calcaneal injury in an obese dog: case report

The purpose of this study was to describe a pantarsal arthrodesis using a medial locking plate in an overweight dog. A 5-year-old, 28 kg, female dachshund presented with a left plantigraded hindlimb with calcaneous osteolytic injury and bone exposure. First, the patient was treated for the skin wound and started on a weight-loss program. A customized locking plate was used in the pantarsal arthrodesis. A normal hindlimb position and gait were observed after 27 days, and bone fusion was achieved at 60 days postoperatively. Implant removal was performed at 120 days, and the patient was discharged. The dog was kept on weight-loss therapy until it achieved a body weight of 11 kg. The customized bone implant used for pantarsal arthrodesis proved feasible and effective in treating an obese dog with low bone density.

Pantarsal arthrodesis with a locking plate as treatment for reabsorptive calcaneal injury in an obese dog: case report

The purpose of this study was to describe a pantarsal arthrodesis using a medial locking plate in an overweight dog. A 5-year-old, 28 kg, female dachshund presented with a left plantigraded hindlimb with calcaneous osteolytic injury and bone exposure. First, the patient was treated for the skin wound and started on a weight-loss program. A customized locking plate was used in the pantarsal arthrodesis. A normal hindlimb position and gait were observed after 27 days, and bone fusion was achieved at 60 days postoperatively. Implant removal was performed at 120 days, and the patient was discharged. The dog was kept on weight-loss therapy until it achieved a body weight of 11 kg. The customized bone implant used for pantarsal arthrodesis proved feasible and effective in treating an obese dog with low bone density.(AU)