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Ankle Plantarflexed and rigid

Discussion in 'Biomechanics, Sports and Foot orthoses' started by David Smith, Jan 16, 2014.

  1. David Smith

    David Smith Well-Known Member


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    Hi guys

    Set out below are the details of a case I have seen this week for a 62 year old male who has an accident at work in 2012 and crushed his right ankle joint.
    He gets severe pain when weight bearing on the right forefoot, which of course with the right foot ankle joint fused and fixed in plantarflexion he must do during walking. He has had a shoe made by the NHS which is a simple heel lift of 30mm on the right.
    After reading thru the case could you suggest / discuss any intervention design you might go for? He is not really interested in any sort of external brace or cam boot.
    Do you think extra pitch needs to be built into a bespoke shoe or do you think an adapted OTC shoe such as Dr Comfort could be modified to give a good outcome. I've suggested modified DrC might work but I'm not sure about the pitch of the shoe with the plantarflexed foot - X ray Picture attached

    Main complaint:

    Painful right ankle following traumatic injury

    Instructions:

    Rehab of injury to right ankle - Initial Biomechanical report request by Broadspire.

    History:

    2 years ago a Brick culvert (arch) collapsed on Mr P causing crush injuries resulting in severe right ankle injury. See Report sent by Broadspire for follow up treatment and rehab - orthopaedic and physio. Also tore ligament in left knee but rehab of knee is fairly good.

    R Ankle is very painful to walk on for more than 15mins also ankle swells.

    He reports that for several years previous to accident he did have lumbar back pain that laid him up for a week or so at a time. No other med hist admitted except for Blood pressure medications.

    Mr P reports shooting pains when weight bearing ambulation that gets worse with time. Also another shooting pain that goes down the right leg that comes on when either walking or non weight bearing - see note above on previous lumbar pain

    Patient objective:

    Objective of Rehab and this Podiatric biomech treatment is to allow Mr P to return to light work (construction) and walk with less pain. He would like steel toe cap boots and a variety of footwear for various activities including trainer type shoes.


    Initial Bmech assess [13/01/14]

    No ankle saggital plane RoM (Range of Motion) - very restricted STJ rom. midfoot Roms restricted esp 1st ray. 5th ray is almost normal, frontal plane RoM midfoot very restricted.

    Visual of walking with NHS orthopaedic shoe (built up heel right only plus more roomy upper) is quite symmetrical with a little antalgic hesitation on right stance phase during early left swing phase and some minor rocking side to side with early off loading of right foot onto left foot.

    Low stiff 1st ray/mpj right. equinus forefoot and of course equinus ankle right. Left foot fairly normal/standard in all respects.

    In stance without shoes the right heel is 30mm off the ground with forefoot weight bearing and this effectively makes the right leg longer by this amount.

    The right hip therefore is that much higher than the left - this may be causing an impingement in the lumbar spine and contributing to a sciatica type pain.i.e. there is a functional LLD = leg length difference

    In walking with NHS modified shoes mr P keeps the upper body straight but the left pelvis lifts and drops during swing thru to foot strike as the pelvis rotates about the right hip - this is likely to cause overuse stress in the right hip abductor muscles and hip joint.

    The interesting point to note here is that by dropping onto the left foot and shortening the left swing phase Mr P has developed an antalgic compensation to off load the right ankle in the saggital plane progression and from direct ground reaction force, which effectively reduces ankle dorsiflexion moments and ankle joint compression forces during right stance phase. This feels advantageous to Mr P in terms of pain relief at the ankle but as explained earlier may have a detrimental long term effect in terms of pathological changes in the lumbar spine and right hip.

    Today [13/01/14], as a test, I fitted extra temporary heel lift to the left shoe in order to make both legs functionally equal length. Mr P felt this was more comfortable in resting stance. However he felt the ankle was more painful during walking.
    This anomaly is due to the fact that when he walks with equal leg length he does not have the off loading effect of shifting the body weight onto the left leg both in magnitude and timing which resulted in less load for a shorter time = less pain.
    He also takes equal length steps, whereas in the former the left step has a truncated swing phase in order to quickly off load the right side, this also reduces propulsive phase time and force magnitude in the right foot. Therefore, in the latter case, the ankle is loaded with greater forces for a longer time in this configuration. However what may be required here is a rocker action shoe with an increased pitch and heel lift to off load the dorsiflexion moments about the ankle and learning to take shorter steps. The left also requires heel lifts to equalise functional LLD.

    I also note the 1st ray/mpj right foot is low and stiff but there is no accommodation for this in the NHS orthotic design. This effectively blocks saggital plane progression (forward motion) and increases dorsiflexion moments about the ankle joint.

    Main points of intervention:

    Mr P has right ankle that is fixed in dorsiflexion following a traumatic crush injury that resulted after healing in a fragmented and fused ankle joint. This is painful to weight bearing ambulation and especially from dorsiflexion moments about the ankle joint due to ground reaction forces (GRF) acting on the forefoot at late stance-propulsive phase of gait.

    Objective:

    To reduce the dorsiflexion moments and GRF compression forces about the ankle joint during walking.

    Conclusion and recommendations:

    1) Make shoes with equal height heel lift additions, 2) add rocker design in to shoe sole unit. 3) Redesign foot orthoses including 1st MPJ c/o right. additional option 4) Fit rigid ankle brace with rocker action - design yet to be decided.

    I tried him with a TM Airwalker but he was adamant that he would not use it even tho this would completely off load right ankle external dorsiflexion moments,


    [​IMG]
     
  2. drdebrule

    drdebrule Active Member

    The case you have presented and the treatment options you are considering are very appropriate and seem logical. Good job.

    I vote extra pitch on the bespoke shoe is more likely to be successful given the abnormal walking pattern. The extra depth orthopedic pre-fab shoes would cost less, but might not hold up as well. Would the lift on the left side be more successful if it was a full length lift and not just a heel lift to compensate for the LLD? Just another thought.

    Also, I do not think patient should return to construction work given his difficulties walking. He might benefit from walking with a cane.
     
  3. drsarbes

    drsarbes Well-Known Member

    Hi David
    Interesting case.
    I can't read the date on the xray. Is this at the time of trauma?
    What does it look like now? He may be a candidate for a revision ankle / STJ fusion.

    Steve
     
  4. David Smith

    David Smith Well-Known Member

    Hi Steve

    Thanks for your interest. Yes this is an X ray just after the accident. There were no recent X rays available. There were MRI's but they were not very clear and I could not take copies off the CD. There were X rays with the Frame in place but they seemed to be more focused on the frame than the bones and are very indistinct. My thoughts were similar to yours in that he would be better off with an ankle joint fused with the foot at 90dgs to the tibia then orthopaedic footwear would be easier to make and more effective. However it is the surgeons opinion that this would only be possible if the ankle joint were removed because it is in too many pieces to fuse successfully. He could not guarantee the outcome and he felt there would be resulting problems with a short right leg. The patient has therefore decided he does not want surgery. He has already spent a long time with a frame on the leg and various surgical repairs to get where he is now.

    Here's an APview with frame attached, unfortunately for some reason I cant get the lateral view off the CD (This is April 2012 BTW)

    [​IMG]

    Cheers Dave
     
    Last edited: Jan 21, 2014
  5. David Smith

    David Smith Well-Known Member

    Steve

    I was think of getting new X rays because it looks from the old ones that the calcaneus is separated from the talus and that is where the equinus deformity comes from. (see diagram)


    [​IMG]

    If I ordered new X rays would you be able to say anything in terms of your opinion on surgical intervention by viewing them?

    Dave
     
  6. RobinP

    RobinP Well-Known Member

    I can't see much fault in what you are suggesting Dave, i would be doing the same. If you modify a stock shoe with a 30mm pitch extra, the shoe cannot take it and will "flatten the upper". If you flex the sole of the shoe to accommodate an extra 30mm pitch, you will see what I mean.

    2 left field suggestions - proximal loading. Transfer the loading to the calf. Involves using pre preg CF and bespoke CF design to create an anterior strutt that could be rivetted into the steel toe cap and transfers load to a calf band. Imagine a prosthetic blade sitting on top of the foot and fixed to the boot

    Other suggestion - trans tibial amputation - most likely way to give a patient back almost completely full function/ability to participate in sports/work and be more or less pain free. Big, BIG step though and needs to be very well thought out

    Rp
     
  7. drsarbes

    drsarbes Well-Known Member

    Hi David
    Interesting.
    I cannot recall seeing a separated STJ causing equinus. If the talus were anteriorly displaced, perhaps, but I don't see that on the original Xray.

    2 thoughts re: surgery; One would be an ankle/STJ fusion via biomet intermedullary pin.
    Two - ankle replacement (in bone).

    Good luck

    Steve
     
  8. efuller

    efuller MVP

    A new x-ray and a new surgeon. This is one of those cases where almost any surgical result would probably be better than what he has now. Really, the surgeon is worried about a leg length difference? We are talking about huge lifts now. Too many pieces. If this is over a year since the original injury those pieces probably have fused together. (New x-ray) Does the patient want to avoid surgery because of what the surgeon said? Does he really not mind wearing a 4 inch heel on one or both sides? He came in complaining of pain on weight bearing on the affected side. Is the surgeon worried that post op it's going to hurt worse than it does now? Is the surgeon the one who treated the original injury?

    Eric

    In the first x-ray, I don's see any separation of the calcaneus.
     
  9. David Smith

    David Smith Well-Known Member

    Cheers Robin Good thoughts

    Regards Dave
     
  10. David Smith

    David Smith Well-Known Member

    Thanks Steve and Eric for your comments

    I see if I can talk to the surgeon (they're a bit allusive and shy) maybe seek a second opinion. There's a local Orthopod surgeon I have in mind who specialises in foot and ankle, his work is excellent.

    Dave
     
  11. drsarbes

    drsarbes Well-Known Member

    A shy surgeon???!!!!! HAHAHA

    Steve
     
  12. musmed

    musmed Active Member

    Dear Dave
    If the ankle ios fused as you say, why does it hurt
    is there avascular necrosis occurring. 12-14 months post trauma is a good time for it to start (Nigg) got the paper somewhere.

    Suggest a bone scan or MRI.
    a question i would ask the patient is: say 2 months ago did you get pain and if so how far did you walk before it came on. what I am looking for is
    1. vascular problems secondary to necrosis impinging on the small vessels due to the collapse of the bones.
    2. any diabetes? always missed

    I would be interested to hear what others say
    Regards
    Paul conneely
    www.musmed.com.au
     
  13. David Smith

    David Smith Well-Known Member

    Good Questions Paul

    The medial and lateral; malleoli are shattered and fused so I would assume osseous impingement (including loose bodies and osteophytes) would be the cause of pain. The surgeons reports that "the bones are fuse from clock position 8-4 in a honeycomb formation" I have no idea what he means by that odd description other than there are lots of broken bits fused together.

    He denies diabetes although he does report poor healing i.e. wounds take about twice as long as expected to heal and in hospital (so one would assume thorough investigation for diabetes) they had to take special measures to ensure healing of surgical wounds and especially the frame fixing penetrations.

    I hadn't considered any necrosis and he does have a persistent small area of bruising between the anterior ankle mortice over the talar head where the pain is located. I'll ask that question. I have sent him for new X rays

    Cheers Dave Smith

    PS Here a pic of a cast of his foot and ankle in the fixed plantarflexed position
    You can see by the relative positions of the forefoot, heel and tibial shank that it is more of a fore foot equinus than an ankle joint plantarflexion - this is why I have ordered new X rays so I can see the relative positions of the osseous components, which might give me improved insight into hoe to desing the shoe/orthotic intervention.

    [​IMG]
     
  14. musmed

    musmed Active Member

    Dear Dave
    When I looked at your photo of the plaster cast I could not be more alarmed!
    In the back ground there are NOT 1 BUT 2 hammers.

    By the look of them I bet you have elicited knee reflexes in all, even in the dead!

    Regards
    Paul Conneely
    lovely day 35 centigrade.
     
  15. David Smith

    David Smith Well-Known Member

    Ah yes its that the old and well known engineering principle, if you can't fix it get a bigger hammer. As you can see by the pic below - There's not much I can't fix :dizzy:


    [​IMG]

    Dave
     
  16. David Smith

    David Smith Well-Known Member

    Robin P

    I put the proposal of transtibial amputation (BKA) to my customer but he wasn't to enthralled with the idea as one would expect but we did discuss it in detail and I found some nice resources online for him to read and view and digest as a possibility for the future if conservative treatment doesn't fulfill his expectations.

    Steve
    we also talked about a second opinion regarding preservative and reconstructive surgery but he felt that he'd had enough surgery but again if the conservative treatment didn't work out well he will put that on the back burner as a possibility for the future.

    AmputeeOT: How a definitive carbon fiber prosthetic leg works - YouTube

    http://www.youtube.com/watch?v=ln7vow0pxXY

    A Manual for Below-Knee (Trans-Tibial) Amputees

    http://www.oandp.com/resources/patientinfo/manuals/bkindex.htm
     
  17. musmed

    musmed Active Member

    Dear Dave
    to steal the words of Crocodile Dundee, "Now that's a hammer!"
    regards
    Paul C
    bloody hot and a magnificent day (about time)
    www.musmed.com.au
     
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