Subluxed patella and orthotic treatment ?

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Hi Folks have a mechanical question.

Have a patient Right knee patella sub-luxes laterally on flexion of the knee and will fully lux from time to time.

Patient is 13 years old female.

Problems began 12 months ago after fall.

As patient flexes knee the patella tracks laterally, when the knee is in a fully extended position the patella sits within normal limits ( WNL) .

Muscle waisting right quads , but knee Q angle, tibial torsion WNL.

Medially deviated STJ axis
increased Dorsiflexion stiffness at 1st MTP joint
Very high supination resistance.

Patient is addressing quads muscle strength with Physiotherapy , she has an knee brace which she only wears when playing sport as instructions were given to her.

Ive not seen the brace but it helps so she will now wear it all the time and will review the brace next week.

Patient has had an orthopedic consult as was told that she would need an operation to transfer the insertion of the patella tendon medially - but this is in 3-4 years when the growth plates have fused.

This is how I´m looking at it - knee flexion - lateral tracking of patella - subluxation.

With Knee flexion we have positive power flow of internal tibial rotation and STJ pronation.


So heres my question with the medial deviated STJ axis and increased Supination resistance if I use an Orthotic reaction force such as medial skive and I can achieve an increase in external rotated position of the tibia which will therefore mean the Femur is more internally rotated on the tibia , which If I´m thinking correctly may help to reduce the lateral tracking of the patella on knee flexion.

But I would like some help discussing the mechanics of it all or if I´m thinking correctly.

Thanks for your time.

 

Michael I have found orthotic intervention in patellar tracking problems less effective than isometric exercises. The Vastus Medialis Obliquus (VMO) acts to pull the patella medially during the last 30 degrees of extension, while the other quad muscles exert a lateral pull on the patella. The VMO in a large segment of the population is less developed than the middle and out quads and I have found this to be the case often in patellar tracking complaints.

Try having the patient perform:

Isometric leg lifts; contract the quads while lying supine flat on the floor. Slowly raise the leg to 45 degrees, hold for 1 second and concentrate on contracting the VMO again, slowly lower the leg to resting and relax. 15-20 reps, 3 sets.

Isotonic quarter squats; Stand back to a wall and squat down 1/4 of the way (about 30 degrees). Push yourself up contracting the quads, hold for one second and concentrate on the VMO, relax, repeat 15-20 reps, 3 sets.

This regimen works well and once their pain is down and they are strong enough they can add weight such as a knee extension machine and squats on a Smith machine.

Just my two cents.

 

Thanks David the physios got her on atraining program no time to go into detail today - will look at it next week . I agree with the VMO being important to medially pull the patella - which was the idea behind externally rotating the tibia to have the femur be medially deviated to the tibia.

Then hopefully have the patella ´sit´less subluxed due to the tension in the tendon (medial) from the change in position in the tibia in relation to the tibia but I might be blowing hot air.

 

Mike,

I know you are a fan of your research articles so this fairly recent one may be of interest:

http://www.optechsportsmed.com/article/S1060-1872%2809%2900170-1/abstract

 

The assumption you are making is that you will create external rotation of the tibia relative to the femur with your foot orthotic. I don't feel that this a good assumption. I'd agree with the notion that you should concentrate with the medial quads. If you want to pull the patella more medial relative to the femur, the vastus medialis is in the perfect position to do this. I've had weakness in my own vastus post injury and took me a while to figure out that was the problem. Knee pain went away after strengthening.

Even if you did achieve rotation of the tibia relative to the femur, that still doesn't mean "unopposed" lateral muscles still won't pull the patella into subluxation.


Eric

 

PFPS - distal factors - with a medial deviated STJ axis orthotics should benefit.
- local factors - VMO is obviously critical but not easy to get going. many closed and open chain exercises work and it seems therapists need to be creative because not everyone responds to the same exercise. Also try tape or braces as they often have benefit. Even sham taping can help!
- Proximal factors - It seems cookie cutter now that improved hip abd/ext rotation strength is critical.

check out:
Patellofemoral pain syndrome: proximal, distal, and local factors, an international retreat, April 30-May 2, 2009, Fells Point, Baltimore, MD.
Davis IS, Powers CM.
J Orthop Sports Phys Ther. 2010 Mar;40(3):A1-16