Legg-Perthes?

Re: Legg-Perthes?

Anonymous — Wed, 19 Jan 2011 11:20:00 GMT

That's fantastic advice, thanks Malcolm!

I'd scared myself about missing a subtle lesion and giving inappropriate advice after Googling the condition and gleaning some outdated advice:

"If the femoral head is round, the joint space parallel, and the femoral head and acetabulum congruent, strict immobilization of the patient in a small space (cage) will usually result in a resolution of the radiographic and clinical problem. During the enforced rest, the animal is allowed out of the cage only to maintain its toilet training. The animal is carried to and from the cage and kept on a leash during evacuation (Fig. 82-4).

Monthly radiographs are taken to follow the progression of the disease. Immobilization of the animal is continued until there is complete resolution of the radiolucent areas. If collapse of the femoral head occurs during the confinement, surgical treatment is performed.

Strict adherence to this form of treatment yields a dog with nearly normal radiographic appearance of its femoral head and complete return of pain-free motion and a normal gait. It takes 4 to 6 months before the femoral head heals sufficiently to permit unrestricted weight bearing. Any compromise to complete immobilization will result in the collapse of the femoral head and a poor outcome. " (http://cal.vet.upenn.edu/projects/saortho/chapter_82/82mast.htm)

Regular exercise and NSAIDs and managing the dog clinically rather than based on radiographs sounds much better advice and a lot less scary

Re: Legg-Perthes?

Malcolm Ness — Wed, 19 Jan 2011 09:11:57 GMT

Can't really tell from the pics whether or not this is Legge-Calve-Perthes disease.

The pathogenesis of LCP involves an ischaemic necrosis of the bone of the femoral capital physis. The articular cartilage derives its being from the joint fluid and consequently is spared. However, as the subchondral bone dies and collapses, the cartilage loses its support and deforms. All the while the bone is revascularising and we end up with a deformed hip with a secondary OA. Pain arises from the ischaemia in the early stages, then the collapsing bone and ultimately from the oa.

Many of these cases do remarkably well without specific treatment (or diagnosis!) and in fact it is not unusual for the diagnosis not to be made until relatively late in life. My approach is initially relatively conservative - encourage normal exercise and use NSAIDs to control pain in the hope that the joint will settle down, remodel and end up comfortable and functional. Salvage surgery is sometimes indicated but note that, contrary to what has been implied earlier, that is a clinical and not a radiographic decision - it really doesn't matter how bad the rads look, if the dog is comfortable and functional then it isn't a surgical case.

Surgical options are excision arthroplasty (EA) or total hip replacement (THR). Excision arthroplasty is reasonably good at reducing pain and will usually give an acceptable (but very very far from normal) functional outcome. EA is a million miles away from being the benign, effective procedure that some surgical enthusiasts would have you believe but it does offer a viable option in painful, disabled patients. THR is possible in many of these very small patients and though costly and technically very challenging, offers the potential of complete pain control and a return to life-long normal athletic function.

Re: Legg-Perthes?

Michael Woodhouse — Tue, 18 Jan 2011 20:23:48 GMT

[quote user="Mark Holmes"]I have seen lots of little JRT type dogs who trot on three legs, not sure why, but it does actually look like less effort for them to do so. [/quote]

My Patterdale does it. Always put it down to patella luxation, but I have no evidence of that and like a good vet's dog she has received no diagnostics...

Re: Legg-Perthes?

Dagmar Steele — Tue, 18 Jan 2011 16:51:53 GMT

In my opinion usually the three leg thing in JRT is because of patella issues, but doesn't cause pain in the hip. Here right hip looks suspicious and is painful, if in doubt show pics to specialist or put on painkillers and do another one in two or four weeks, Perthes should have progressed by then.

Re: Legg-Perthes?

Mark Holmes — Tue, 18 Jan 2011 16:28:12 GMT

To be honest I have never had the pleasure of examining them, its just JRT type dogs were a common feature amongst the farmers etc that I grew up with and a good half of them would do it. Some would run on three legs then switch to the other hind leg for a while others seemed to ahve a favourite but a good half of them seemed to do it and they would be persistant in doing it. Sound at walk and gallop but when trotting would use one or the other hind leg and not the other.

Re: Legg-Perthes?

Kate Richardson — Tue, 18 Jan 2011 16:24:48 GMT

I would agree lots of JRT types do the 3 legged thing, and the ones I have examined for this when mentioned in a booster for example show no pain whatsoever, but I can't say I have xrayed many of them to see if there is a problem, have always just accepted it as a JRT thing! Maybe Malcom Ness could comment as to whether anyone has looked to see if they have any pathology? Most seem to use leg perfectly well when they want to! But also other small breeds do the one legged thing intermittently due to patellar luxation (not that this is the case in your dog)

Re: Legg-Perthes?

Anonymous — Tue, 18 Jan 2011 16:14:59 GMT

Thanks Mark. This dog does genuinely seem to be in pain on my attempts to extend right hip (I'll check it again at post-op check and make sure is genuinely and definitely unilateral discomfort and isloated purely to manipulation of hip). The owner mentioned that he knew a lot of terrier-like dogs ran around on 3 legs and that's why he wasn't really bothered (I'll confess to not having been too sure whether this was correct or not or just a random client-comment, so thanks for confirming this observation). Have any of the JRTs you describe had pain on examination, but without identifiable pathology, or has the physical exam typically been entirely normal with no indication of pain on exam?

Re: Legg-Perthes?

Mark Holmes — Tue, 18 Jan 2011 15:54:37 GMT

[quote user="David Beattie"]Guess I'm struggling for differentials to Perthes - any suggestions?[/quote]

I have seen lots of little JRT type dogs who trot on three legs, not sure why, but it does actually look like less effort for them to do so.

Re: Legg-Perthes?

Kate Richardson — Tue, 18 Jan 2011 15:00:45 GMT

All I can add is the right hip region definitely looks wrong! I would have to defer to my boss (an orthopod!). Maybe other possibilites would be remodelling secondary to a fracture? poss a growth plate injury? But I am most definitely not an orthopd so don't quote me on that!!

Re: Legg-Perthes?

Anonymous — Tue, 18 Jan 2011 14:52:51 GMT

Thanks Mark - I agree they're unlikely to pass a BVA hip score submission... Legs were pulled back in the VD view under medetomidine/morphine premed prior to GA (was pretty flat out) - right hip did have limited extension, but I suspect in hindsight a better radiograph would have been attainable even under the sedation...

Must say I'm not convinced of Perthes dz from x-rays either, but had created tunnel vision from my initial clinical assessment - so thought I'd see if anyone could look a bit more objective at them. Has been going on at least a couple of weeks from what I can tell and is definite pain which I think is isolated to hip joint (and exam of patella was normal). Guess I'm struggling for differentials to Perthes - any suggestions?

Cheers.

Re: Legg-Perthes?

Mark Hedberg — Tue, 18 Jan 2011 14:44:32 GMT

I would suggest the legs be pulled as far caudal as possible. Otherwise you're just getting oblique views of the joint. I'm not convinced of perthe's disease from these xrays, but i cheerfully leave that to my betters. Were these xrays taken under anesthesia?