Clinical Article Club - Patella Luxation in Dogs

RE: Clinical Article Club - Patella Luxation in Dogs

Arlo Guthrie — Mon, 24 Apr 2023 13:53:19 GMT

That brings this Q&A session to a close, because apart from anything else, Mike is now away on hols. But thanks for the questions, and thanks Mike Farrell for your answers.

RE: Clinical Article Club - Patella Luxation in Dogs

Mike Farrell — Mon, 24 Apr 2023 13:48:10 GMT

I strongly support the involvement of physiotherapists in patellar luxation therapy. If I personally suffer a musculoskeletal problem, I want a physio on my team. Indeed, high quality physiotherapy has spared me from knee surgery and shoulder surgery. Any pet of mine deserves equivalent care, and my clients are offered the same treatment I'd give my own pet.

Our top priority as veterinary orthopaedic surgeons must be to operate only when we have to. If we need to operate, we should want our team to contain professionals who are genuine rehabilitation experts. The regular 3-way communication I mentioned means that a physiotherapist defines specific, measurable, achievable, relevant and time-constrained goals. They share these with the surgeon working on their team. That surgeon offers input and the team implements a plan. If the patient isn't hitting their targets, the plan can be revised.

The best general advice I can offer you is to engage with specialists in veterinary rehabilitation. There's a Facebook forum called Small Animal Vet Rehabbers - https://www.facebook.com/groups/976440089198714/ - You could, for example, pose your question about the efficacy of a physiotherapy programme for improving core strength and client involvement. I'm confident you'd receive an overwhelming response.

RE: Clinical Article Club - Patella Luxation in Dogs

David Mills — Mon, 24 Apr 2023 09:15:34 GMT

[quote userid="29375" url="~/001/veterinary-clinical/small-animal/orthopaedics/f/discussions/30632/clinical-article-club---patella-luxation-in-dogs/241373#241373"]Is there a canine exercise capable of selectively activating part of the quadriceps whilst deactivating another? The answer is no. Physiotherapy is good for engaging pet owners and improving a dog's core strength, but the idea it can improve patellar tracking by selectively strengthening part of the quadriceps is fanciful.[/quote]

With this in mind, apart from improving core strength and engaging pet owners (is there evidence for the efficacy of either?) what role do you envisage physiotherapists playing in "regular three-way communication between owners, veterinary physiotherapists and orthopaedic surgeons"? Does their involvement potentially muddy the waters?

RE: Clinical Article Club - Patella Luxation in Dogs

Mike Farrell — Tue, 18 Apr 2023 14:23:18 GMT

The aim of physiotherapy for patellar maltracking is to increase the strength of the vastus lateralis and simultaneously weaken the vastus intermedius, medialis, and rectus femoris. The latter is the muscle which we're most concerned about in canine MPL. When we anaesthetise a dog with MPL and completely relax their muscles, MPL grade decreases because the rectus femoris is so important and we've taken it out. Which quadriceps exercise can simultaneously activate the vastus lateralis and deactivate the rectus femoris? Of all exercises available to human healthcare physiotherapists, the quad extension is the best for isolating the quadriceps. Here I'm doing it with my feet internally rotated, neutral and externally rotated. In principle, external rotation will maximally activate the rectus, whilst external rotation will maximally activate the vastus lateralis. In practice, you can clearly see all 4 parts of my quadriceps are activated. Deep squats are the same, and this is proven beyond doubt in many studies. Is there a canine exercise capable of selectively activating part of the quadriceps whilst deactivating another? The answer is no. Physiotherapy is good for engaging pet owners and improving a dog's core strength, but the idea it can improve patellar tracking by selectively strengthening part of the quadriceps is fanciful.

RE: Clinical Article Club - Patella Luxation in Dogs

Mike Farrell — Tue, 18 Apr 2023 14:07:56 GMT

Hi Gillian,

Here are your answers:

1. Surgery isn't indicated in a skeletally mature dog unless it is symptomatic - Correct

2. Surgery has minimal impact on the development of OA - Correct (and we're talking about patellofemoral OA which is focal)

3. In growing puppies, deformity occurs secondary to patellar luxation, not the other way around. Intuitively, this means that the more time the patella spends luxated, the worse the deformity. Importantly, grade is a moving target in puppies, so today's G2 might be tomorrow's G3. If I see a puppy with asymptomatic MPL, there are other factors to consider including rate of growth (age of diagnosis and ultimate dog size). If I see a puppy with G1-2, I'll be watching them very closely. On average, iff they're 'high G2' or more, I'd be recommending surgery.

RE: Clinical Article Club - Patella Luxation in Dogs

David Mills — Tue, 18 Apr 2023 10:36:18 GMT

How practical do you think it is to manage these dogs via physiotherapy? The practices are very different between human and veterinary medicine - the latter cannot reliably focus strengthening to a particular muscle group or groups. Moreover how would this be documented clinically? I also suspect there is significant confirmation/selection bias in the human field around this regarding physiotherapist outcomes and decision to operate or not, and long term outcome measures are lacking - with this in mind I would be concerned about recommending we follow this approach with a lack of convincing evidence as to its efficacy for our patients.

RE: Clinical Article Club - Patella Luxation in Dogs

Gillian Mostyn — Tue, 18 Apr 2023 09:44:00 GMT

Thanks Mike Farrell - thats really helpful

The part I found most useful was regarding when surgery is recommended. I was under the impression (and correct me if I am wrong) that surgery isn't indicated in a skeletally mature dog unless it is symptomatic, and surgery has minimal impact on the development of OA. But when it is an incidental finding in a younger dog whose owners haven't seen any problem, and they always ask 'is it going to be a problem', are you saying that early surgery may reduce the degree of deformity? Would you recommend surgery in a puppy if it isn't lame / hopping - and if so, at what grade?