Distal tibial tuberosity translation using TTA implants for the treatment of patella alta in large breed dogs. Surgical technique and clinical outcome.

INTRODUCTION: Medial patellar luxation frequently occurs in dogs resulting in lameness with increasing incidence in large breed dogs. Patella alta has been defined as a patellar ligament length to patellar length ratio that is greater than two and may predispose to patellar luxation. OBJECTIVE: To describe the surgical technique for stabilization of the distal translation of the tibial tuberosity using tibial tuberosity advancement plates and the clinical outcomes with follow-up for clinical cases of dogs. METHODS: Dogs that were presented with the complaint of patellar luxation and that were concurrently diagnosed with patella alta and were greater than 20 kg in body weight underwent surgery using a tibial tuberosity advancement plate to stabilize the osteotomy. Radiographic assessment of A:PL distance (the ratio of the proximal aspect of the patella to the femoral condyle [A] to the patellar length [PL]), L:P ratio (ratio of the length of the patellar ligament to the diagonal length of the patella), and owner assessment were obtained. RESULTS: Eleven stifles in nine dogs underwent surgical correction with a mean preoperative L:P ratio of 2.47. There were no complications and the lameness resolved clinically. The mean A:PL ratios preoperatively (2.6 ± 0.22) and postoperatively (2.1 ± 0.25) were significantly different (p = 0.0003). All owners were satisfied with the outcome and all dogs had a resolution of lameness with no recurrence of patellar luxation. CLINICAL SIGNIFICANCE: Stabilization of distal translation of the tibial tuberosity using tibial tuberosity advancement implants to correct patella alta in large breed dogs was feasible and resulted in good clinical outcome.

Intraventricular tension pneumocephalus and cervical subarachnoid pneumorrhachis in a bull mastiff dog after craniotomy.

An eight-year-old bull mastiff dog underwent a craniotomy for surgical excision of an olfactory lobe meningioma. Rapidly progressive neurological deficits with cervical pain developed within the early postoperative period. Intraventricular and cervical subarachnoid space air accumulation (pneumorrhachis) was identified through magnetic resonance imaging and computed tomography. Repair of a dural defect using synthetic dura substitute resulted in gradual resolution of neurological signs attributable to the tension pneumocephalus and subarachnoid space pneumorrhachis. Regrowth of the meningioma was not observed. Postoperative intraventricular tension pneumocephalus and air accumulation within subarachnoid space are uncommon but life-threatening complications of intracranial surgery. Early diagnosis and treatment can result in a satisfactory outcome.

Radiographic and clinical changes of the patellar tendon after tibial plateau leveling osteotomy 94 cases (2000-2003).

Patellar tendon thickening (PTT) and patellar tendinosis (PTS) have been discussed in the veterinary literature as a post-operative complication of tibial plateau leveling osteotomy (TPLO). The purpose of this study was to define radiographic PTT, determine the frequency of and risk factors for PTT and PTS, and describe the clinical and histopathological findings of PTS after TPLO. We hypothesized that the location of the osteotomy alters forces placed on the patelloar tendon resulting in PTT or PTS. Radiographs and medical records from 83 dogs undergoing 94 TPLO procedures were retrospectively evaluated. Two months post-operatively, 19 dogs (20.2%) had a normal patellar tendon or mild PTT, 51 (54.3%) had moderate PTT, and 24 (25.5%) had severe PTT. Seven of the 24 dogs (7.4%) with severe PTT had clinical signs consistent with PTS. Only dogs with severe PTT developed PTS (p < 0.0001). The risk factors for the development of PTT include: a cranial osteotomy, a partially intact cranial cruciate ligament (CCL) in conjunction with a cranial osteotomy, and post-operative tibial tuberosity fracture. The only risk factor identified for the development of PTS was a partially intact CCL. Four dogs with PTS improved with conservative therapy and one improved with surgical treatment. Two dogs had tendon biopsies with histopothological review that showed tendon degeneration with lack of inflammation. As only the dogs with severe PTT develop PTS, a caudal osteotomy for the prevention of PTT and subsequent PTS is recommended.

Interstitial fluid pressure and blood flow in canine osteosarcoma and other tumors.

This study aims to characterize interstitial fluid pressure and blood flow in naturally occurring appendicular bone tumors in dogs because high pressure may influence the response of tumors to chemotherapy and radiation therapy. Eighteen client-owned dogs with naturally occurring appendicular bone tumors were included in this study. At the time of surgical biopsy, interstitial fluid pressure and blood flow were measured using wick-in-needle probes and laser Doppler flowmetry, respectively, within the soft tissue and bony components of the lesions and in normal muscle. Interstitial fluid pressure within the bony and soft tissue components of the tumors was significantly higher than interstitial fluid pressure in normal muscle. Blood flow in the bony component of the tumors was significantly lower than blood flow in normal muscle. There was no significant difference between blood flow in the soft tissue component of the tumors compared with that in normal muscle. Appendicular bone tumors in dogs have significantly higher interstitial fluid pressure and lower blood flow than do adjacent, unaffected soft tissues. The higher interstitial fluid pressure and lower blood flow may reduce tissue oxygenation and impede drug delivery. The effects of increased interstitial fluid pressure and decreased blood flow should be considered in the formulation of treatment strategies for the clinical management of appendicular bone tumors.

Autologous blood collection and transfusion in cats undergoing partial craniectomy.

OBJECTIVE: To describe the procedure for autologous blood donation and associated complications in cats undergoing partial craniectomy for mass removal. DESIGN: Prospective case series. ANIMALS: 15 cats with intracranial mass confirmed by computed tomographic scan, no evidence of renal failure, and PCV > or = 22%. PROCEDURE: One unit (60 ml) of blood was collected and stored 7 to 17 days before surgery and transfused during the perioperative period if needed. The PCV was measured before donation, before surgery, during surgery, and after surgery to assess effect of donation on PCV before surgery and effect of transfusion on PCV after surgery. Cats were evaluated for donation complications, iatrogenic anemia, and adverse reactions associated with administration of autologous blood. RESULTS: Complications associated with phlebotomy were not detected. Fifteen cats underwent partial craniectomy 7 to 17 days after blood donation; all had histologic confirmation of meningioma by examination of tissue obtained at surgery. Eleven cats received autologous blood transfusions. None of the cats received allogeneic blood transfusions. Transfusion reactions were not observed. Subclinical iatrogenic anemia was detected in 3 cats. Two cats were considered to have received excessive transfusion, and 3 cats received inadequate transfusion. All cats undergoing partial craniectomy were discharged from the hospital and were alive > 6 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Autologous blood donation before surgery was considered safe for cats undergoing partial craniectomy for resection of meningioma. The only complication observed was iatrogenic anemia. The procedure contributed to blood conservation in our hospital.

Acquired arteriovenous fistula secondary to castration in a dog.

A 6-year-old castrated male Basset Hound was examined because of a 1-year history of a pulsating mass in the right inguinal region. The pulsatile mass was diagnosed as an arteriovenous fistula by physical examination and angiography. Surgical exploration revealed that the right testicular artery and vein, the artery of the ductus deferens, and the cremasteric artery were involved in the fistula. The fistula was believed to have developed secondary to castration performed at 6 months of age. The mass and associated vessels were completely excised and signs of recurrence were not observed 13 months after surgery.

Arthrodesis for congenital flexural deformity of the metacarpophalangeal and metatarsophalangeal joints.

A llama, a miniature horse, and a miniature donkey with severe bilateral congenital flexural deformities of the metacarpophalangeal and metatarsophalangeal joints were treated successfully by arthrodesis with dynamic compression plating or external skeletal fixation. The flexor tendons were more taut than the suspensory ligaments and were transected. In the llama, the suspensory ligament was transected, and overcorrection caused ischemic necrosis of one distal limb and subluxation of the other fetlock joint. In the horse and donkey, the suspensory ligament was preserved and wedge osteotomy was performed to correct the deformity.