Dual mobility canine total hip prosthesis: implant characteristics and surgical procedure.

Prosthetic dislocation is one of the most common complications after canine hip replacement. The use of dual mobility acetabular components has been shown to reduce the rate of dislocation in first intent hip replacement in human patients who are at high risk for dislocation. In such implants, a mobile polyethylene liner articulates on one side with a metallic acetabular component and on the other side with a metallic prosthetic head. A dual mobility cemented acetabular component has been designed for use in dogs, and is available for use in association with a previously designed modular femoral component. This report describes the characteristics and the procedure for implantation of this implant combination.

Outcome and complications after dual mobility total hip replacement: fifty cases with a minimum of six months clinical and radiographic follow-up.

OBJECTIVES: To report the clinical and radiographic outcome of a canine total hip prosthesis with a dual mobility acetabular component, with a minimum of six months follow-up. METHODS: The outcome of dogs that underwent primary cemented unilateral dual mobility hip prosthesis surgery by one of the authors for hip dysplasia or trauma, and which had a minimum of six months clinical and radiologic follow-up, was evaluated. RESULTS: Fifty dogs were included in the study. Follow-up ranged from six to 38 months (mean 14.4 months). Perioperative complications were acetabular collapse (n = 1) and greater trochanter fracture (n = 1), both of which were successfully managed perioperatively. Postoperative complications were aseptic loosening of the acetabular component (n = 2; both surgically revised), implant sepsis (n = 3; all explanted), acetabular fracture (n = 1; conservatively managed), greater trochanter fracture (n = 1; conservatively managed) and sciatic neurapraxia (n = 1). No cases of postoperative luxation or femoral implant aseptic loosening were encountered. Outcome was poor for three cases (3 implant sepsis), fair for three cases (including 1 acetabular component loosening and 1 acetabular fracture), and good or excellent for 44 cases (88%). CLINICAL SIGNIFICANCE: There were not any cases of postoperative coxofemoral luxation observed in this series of 50 dogs with dual mobility hip prosthesis. Studies with more patients and longer follow-up are needed to confirm the satisfactory results observed to date with this implant.

Rupture of the quadriceps tendon. A case report in a young dog.

A five-month-old, male, 16 kg, mixed breed dog was presented for an acute non-weight bearing lameness of the right hind limb. A subtotal avulsion of the quadriceps tendon at its patellar insertion was diagnosed through radiography and ultrasonography. Two nylon sutures secured with a stainless steel crimp were placed in a locking loop pattern in the quadriceps tendon and through a transverse 2.7 mm drill-hole in the patella. No external coaptation was used postoperatively. A full functional recovery was observed, and was followed for one year postoperatively. Quadriceps tendon rupture has not been described in the veterinary literature to our knowledge; in humans, quadriceps tendon rupture is a well known entity, often due to systemic disease resulting in weakening of the tendinous structures. In the case presented herein, the dog's history, young age and location, without underlying biochemical abnormalities, led us to believe that the observed lesion was of traumatic origin. The surgical treatment performed was based on that performed in humans and also that which has been investigated experimentally in the dog.

Biointegration of massive bone allografts: imaging and histological studies in cat.

A study was carried out in a cat model to compare three imaging methods (X-ray, bone scintigraphy (BS) and magnetic resonance imaging (MRI] in order to assess the healing of bone allografts. X-ray remains the first technique to proceed, for morphological information and control of devices. BS is very sensitive although unspecific and difficult to quantify in exploration of bone reconstruction. It may be a useful complement of X-ray methods in some pathological circumstances (stress fracture, infection, non union). MRI is a very sensitive exploration of the bone marrow, but not of the cortical bone. In its present state it is of little value in bone graft imaging because of its low specificity and because of metallic artefacts (material, micro particles).