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Innovative approaches discussed at WVOC

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01 November 2010, at 12:00am

DONAL NUGENT reports on the third World Veterinary Orthopaedic Congress held in Bologna in September

NEW research, expert updates and state-of-the-art lectures were at the heart of the third World Veterinary Orthopaedic Congress, held in conjunction with the 15th meeting of the European Society for Veterinary Orthopaedics and Traumatology (ESVOT), in Bologna from 15th to 18th September.

More than a thousand delegates from around the world gathered to hear scientific presentations from over 80 speakers on emerging developments in orthopaedics and traumatology, and innovative approaches to diagnostics and therapy.

Prime focus

The state-of-the-art lectures included the latest findings on mesenchymal stem cells in human orthopaedics and the long-term success of post- traumatic knee and cartilage resurfacing with ACI and MACI.

In his lecture “Stem cell therapy for tissue repair: the stem cell-host interaction”, Frank Barry of the National University of Ireland explained the interest in mesenchymal stem cells due to their potential use in regenerative medicine and tissue engineering.

The study he oversaw evaluated stem cell-host interaction in three disease models:

  1. osteoarthritis (OA) of the knee;
  2. myocardial infarction (MI); and
  3. human breast cancer xenografts.

“The results of these studies lead to the conclusion that neither extensive engraftment nor differentiation of the transplanted cells are prerequisites for a useful therapeutic response,” he explained.

Tim Briggs of the Royal National Orthopaedic Hospital in the UK, in his presentation “Cartilage resurfacing with ACI and MACI: have they stood the test of time?”, reviewed the experience of the hospital with autologous chondrocyte implantation (ACI).

Explaining that chondral damage to the knee is common and may lead to degenerative osteoarthritis if untreated, he told delegates: “The intermediate and long-term function and clinical results [of ACI] are promising.” 

Small animal programme

The small animal programme focused on “old favourites” such as the stifle, elbow, patellar luxation and hip trauma, while “newer” topics included revisions, distal limb trauma, legislation and clinical research, and tools to measure clinical success were also prominent.

In his presentation “Managing cruciate disease – where are we now?”, Randy Boudrieau of Tufts University in the USA noted that over 40 different surgical techniques exist for repairing a dog’s knee with a cranial cruciate ligament (CrCL) injury.

“Results indicate a reported success rate of approximately 90% (good to excellent function), regardless of the surgical technique used,” he said. Of the TPLO or TTA techniques (and similar techniques) performed at Tufts, he said: “They are all effective based on a single mechanism – the alteration of the patellar tendon angle, which alters the tibiofemoral shear forces.”

The “small animal complications” stream included a presentation by David Lloyd of the RVC on “Multi- resistant bacteria: current status including management” in which he explained that measures to control infections and guidelines on responsible use of antimicrobials in practice are now being created.

FECAVA, for example, has established a Working Group on Hygiene and the Use of Antimicrobials in Veterinary Practice. “An important component of this process is client education on the avoidance of non- essential antimicrobial administration and full compliance with dosage regimens,” he said.

Addressing another growing concern among vets across Europe, John Houlton of the Veterinary Defence Society spoke on “Negligence claims: can you reduce them?”

Problems often arise when there is a mismatch between the realistic ability of the veterinary surgeon to meet the unrealistic expectations of the client, he said, highlighting the value in obtaining a client’s informed consent (preferably in writing) and providing them with “a jargon-free and readily understood evaluation of the implications of a diagnosis and the risk involved in a chosen treatment programme”.

Good communication is essential throughout and “veterinary surgeons should keep their clients fully appraised of mounting costs as well as their animal’s clinical progress”, he said.

Fractures

Thursday’s “in-depth seminar on challenging fractures” included a presentation by Noel Fitzpatrick of Fitzpatrick Referrals on “Challenging elbow fractures”. Sixty per cent of distal humeral fractures involve the condyle in dogs and 90% of unicondylar fractures of the distal humerus are reported to occur in association with minor trauma.

“Decreased range of elbow joint motion is a common complication associated with elbow fracture repair and minimising the degree of periarticular fibrosis by utilising optimal surgical technique and early post- operative mobilisation of joint movement, including active and passive physical therapy, is imperative,” he said.

In his presentation on skull fractures, as part of the “facial trauma” stream, Thomas Turner of VCA Berwyn Animal Hospital in the USA explained that a variety of fixation techniques can be employed, with some of the more common being interfragmentary wiring, bone plates and external fixators.

“The goals of fracture treatment are precise restoration of the bony architecture in order to achieve normal dental occlusion and support and to restore the dorsal buttress of the facial bones to the upper skull,” he said.

In the “new trends in canine and feline orthopaedics” stream, Sorrel Langley-Hobbs of the Cambridge veterinary school looked at a number of conditions including osteoarthritis (OA) and arthritis in her presentation “Feline forelimb lameness – what if it’s not a fracture or an abscess?”

While cats commonly suffer from OA, the clinical signs tend not to be as pronounced as in dogs. “OA is more common in the forelimb as compared to the hind limb,” she explained, adding that “while it is difficult to modify a cat’s exercise, regular movement and weight loss should be encouraged”.

Imaging

The programme on advanced imaging included a presentation by Thorben Schulze, of the Equine Clinic Burg Müggenhausen in Germany, on “The pre-purchase MRI of horses – definition and clinical implications”.

Dr Schulze explained that standing MRI has developed into an important diagnostic tool for equine orthopaedic medicine. “MRI scans allow us to evaluate all anatomical structures in detail and spot all potential changes. It is, also, not rare that multiple problems are seen and that there are findings on lame-free limbs.”

However, in pre-purchase examinations, where there is no sign of lameness or pain, it can be difficult to give a clear picture of what any discovery through the scan could mean for the specific horse. Given the risk of liability to a vet interpreting MRI findings, he said the sensible course of action is to point out the changes only and to avoid any further estimation and comments.

Equine

Presentations in the equine orthopaedics stream included “Critical review of regenerative cell therapy: fat- derived, tendon-derived and synovial-derived cells” in which Allison Stewart (University of Illinois, USA) stated that “most of the current literature demonstrates the source of progenitor cells will significantly impact the progenitor cell function and ability to regenerate tissue.”

Two clinical trials on the use of fat- derived cells for the treatment of osteoarthritis in dogs showed improvement in associated lameness for over three months, while the treatment of injured tendon in horses with tendon-derived progenitor cells improved tendon healing at a histological level.

Practical advice

Finally, Rico Vannini offered delegates practical advice in “The orthopedic examination – tips and tricks to a successful diagnosis”.

“A good orthopedic examination is the key for a successful diagnosis and treatment of a dog with a chronic lameness,” he explained, adding that “it starts with a detailed, careful history” and should always go through the same basic steps: (1) observe the animal while it is moving, standing and sitting; (2) palpate and manipulate the dog; and (3) perform specific examinations.

“A systematic approach helps to avoid missing important pieces of information,” he said. “Where palpations and manipulations do not help to localise the problem, all joints should be systematically examined. The joint most commonly causing lameness of the rear in dogs is the stifle and the joint most commonly causing lameness in the front limb is the elbow joint. So, if a dog is lame on its front it is the elbow and if a dog is lame on the rear it is the stifle, until proven otherwise.”

Pain management symposium

T0 mark the European launch of Equioxx (firocoxib) at the WVOC, Merial hosted its first Equioxx European Pain Management Symposium as part of the pre-congress schedule.

Keynote speaker at the symposium, Professor Wayne McIlwraith of the University of Colorado, explained that the purpose of therapeutic procedures must be “to prevent the progressive loss of articular cartilage, rather than a purely analgesic role” and said that “veterinarians are giving the new generation of selective NSAIDs to minimise inflammation and not only to block pain”.

Prof. McIlwraith’s research group at the university has studied the starting point of inflammation in horses, and believes that deeper understanding of the “inflammatory cascade” is crucial to managing osteoarthritis (OA).

“The use of NSAIDs allows us to select our level of intervention at fairly specific levels,” he continued, pointing to evidence from the human literature which showed that “we can preserve cartilage better with a COX -2 inhibitor”. He also highlighted emerging studies that show a much lower level of side effects such as gastro-intestinal toxicity, which are linked with the use of phenylbutazone in ponies and young foals, as a key reason for choosing COX-2 selective/COX-1 sparing drugs.

Prof. Willem Back of Utrecht University in Holland presented delegates with the findings of a pivotal study, “The use of force plate measurements to titrate the dosage of a new COX-2 inhibitor in lame horses”, which brought together research from Europe and the US and assessed 64 horses with grade 2 to 3 lameness based on the five-point (AAEP) scale.

The force plate method allows researchers to specify exactly where pressure is exerted in joint movement and all participating horses exhibited chronic lameness due to osteoarthritis in at least one of the front limbs.

The study found that treatment by firocoxib reduced lameness on average by 0.5 grades on the first day and by 1.1 grades after six days of treatment. It also established the optimum dosage. “We concluded that the 0.1 dosage was the effective dose in the control of pain and inflammation associated with OA,” he said.

Dr Matthias Pollmeier of Merial in France presented results from a field trial validation of the efficacy and acceptability of firocoxib in a group of 96 lame horses. He explained that, in addition to efficacy, one of the key messages from the study was to do with safety.

“Vets often do not see the side effects of commonly used NSAIDs, as they will often only see the horse at the beginning and the end of a treatment programme. The study proved that firocoxib, even when given at doses up to five times the recommended level for up to 42 days, was not only highly effective for the control of pain and inflammation but well tolerated in 98% of horses.”