Laurie's Blogs.

Hi Laurie,

One of my techs had a TPLO done on her dog about 8 months ago.  She did rehab on the dog and it recovered well except that when I saw it the other day at a clinic party, I noted that when the dog walks her TPLO leg has internal rotation of the tibia and thus " winging out" of the hock, She swims the dog at least twice a week and walks it 30 minutes BID. I also think there is some muscle atrophy of the hamstrings in this dog.  This dog had a fracture tibia on the other leg, which was repaired about a year before its cruciate surgery. 

Have you seen this odd tibial rotation? I wonder if it is the vastus laterals?? I just wondered about your thoughts on this.

JH

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Hey J!

So immediately the things that pop into my head to look for:

1) MCL involvement / laxity.

2) Realizing that the pes anserine is lifted and only reattached to fascia in the surgery, there would be an imperfect pull of the sartorius, gracilis, semitendinosis (and/or there could be a pulling away of the sutured soft tissues – kind of like a muscle tear - of any of the aforementioned muscles at any point subsequent to the surgery.  And while a reduced pull on that medial side of the tibia would not PULL the tibia medially / internally, the dog may be compensating by foot placement alterations... thus giving the appearance of medial rotation of the tibia.  People do all sorts of weird things to adapt to problems... without realizing it as well.

3) Perhaps they over rotated / over corrected the tibial plateau, and in order to get full extension, the tibia has to torque medially to accommodate end range (I just played with my bones for 10 minutes to ’see’ that one).  I think that some of the surgeon are perhaps too obsessed with getting to a specific tibial plateau angle that they forget that dog has to live with the two different tibial plateaus... which is going to mess up gait.  Period. (Think two different styles of shoes - high heels & flats... try it yourself and see how you walk).

To have hamstring atrophy is not uncommon- as the attachments of Semi Tend & Semi Memb will be affected.  However, atrophy of these could impact the control of the tibial position in early weight bearing (allowing external tibial rotation), which may auto-correct in weight wearing... giving the winging out & tibial rotation look.  (Vastus lateralis is the quads powerhouse - I have yet to see any major issues with him specifically… However, that being said, poke around there to look for myofascial triggerpoints… But I can’t say as I can see a direct correlation to the gait you describe.)

So, there are many factors. I’d go with: look at / examine the MCL, feel for muscle bunching proximal to the pes-anserine to look for a muscle tear.  Palpate the vastus lateralis. Try to build the hamstrings: EMS with 3-leg stands.  3-leg stands with different directional pulls on the leg being held up (to see which activates hamstrings of the standing / affected leg) and/or theraband-pulls around the standing leg, controlled hill walking up and down or rear-legs-only on a treadmill - or backwards on a treadmill).

Great question - wonderfully though provoking...

I hope this helps!