post op mlp now lat luxating patella

[rita]

I would really appreciate some advice and wisdom on a case involving an 8 year old Shih tzu who had surgery on one stifle (she had a grade 3 mlp) in Oct, 2016. The surgeon did a lateral tibial tuberosity transposition. He commented that the trochlear groove was of normal depth so a recession trochleoplasty was not performed. Immediate post op was uneventful for her. I saw her briefly 7 weeks post op after she was lame for 3 days (she had been running in the living room just before the lameness occurred). There was a negative drawer, decreased stifle extension and her patella was now tracking laterally. Rads looked good (no pin migration, no obvious radiographic complications).

A colleague had been working with the dog over the past 2 months (ie. gave metacam) and she seemed to improve. The surgeon is reluctant to redo the surgery due to the "lack of lameness". The owner really wants to send the dog back to surgery because she feels the dog is not yet "right".

The most recent history is that the dog is reluctant to go for walks outside (it is crazy icy out here lately) but even inside, she's not enthused about walking. When she ascends the stairs, she hesitates on the first stair and occasionally "buckles" (owner's words). I saw her today and found that there is a 2 cm difference in the standing thigh circumference between the 2 hind legs. When she walks, her hock (on the affected leg) rotates externally. When she sits, there is decreased flexion in the affected stifle and hock. Yet, she is weight bearing quite well for the most part on the surgical leg and has no reluctance to jump up on a couch. The patellar tendon is slightly thickened. She has (not surprisingly) TP's in both of her quads. She also has a RPI. The PROM in the surgical leg is slightly reduced relative to the other leg. What I did notice today (and I could have missed it on the initial exam:() was that her tarsus on the surgical leg would hyperextend. A slipped hock if you will.

My concern is that the hock is causing more of a perceived issue than the stifle. I hope that if we implement some rehab, we can improve the situation but need to convince the owner that that investment is worth it before heading back into surgery. I don't think that surgery will increase function any more than we currently have. Could you offer an opinion on the limited information that I have given you?
Thank you!
Rita

[lehughes]

Hi Rita,

Interesting case!
I am stumped by one acronym - RPI - chiro term? (that's my best guess, my other guesses are even too ridiculous to type!)

I too would be hesitant to jump back into surgery... might as well see how rehab goes.

The thickened patellar tendon is interesting - could be 'new loading' going on and creation of a tendinopathy / desmitis... treat accordingly (i.e. as if a tendinopathy.)

The tarsal hyperextension is likely just to gain end range extension b/c the stifle isn't comfortable or willing to go there, and so to keep gait strides symmetric, the motion and push off has to come from somewhere. Alternately, with total limb weakness, the gastrocs may also have atrophied, allowing for the hyperextension to occur.

So, I'd say try rehab - focusing primarily on specific exercise with the addition of laser for pain management. I'd also think about some low dose NSAIDs just to take the edge off (i.e. 1/2 dose of metacam), OR higher dosing of nutraceuticals (i.e. double dose short term). Add in some joint mobs for the stifle and a bit of triggerpoint work for the quads / sartorius.

I'd be willing to bet that it'll sort out with a little bit of targetted rehab.

Best of luck!

Laurie

[rita]

Thanks Laurie,
I'll let you know how it goes.
Rita