Biomechanics resources

[EthylMethylMan]

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Hey all, I’m an MD hyperbaric and wound doc. Obviously I see a ton of foot ulcers. I’m relatively new and would like to improve my foot biomechanics knowledge. Are there any gold-standard resources you guys use for this?

 

[deleted285117]

Please refer those patients to the podiatrist in your wound center. Thank you 😜

 

[Adam Smasher]

There's a chapter on Biomechanics in Mann's Foot and Ankle Surgery that is concise and explains the subtalar joint really well.

Apart from that, the literature on biomechanics is like the Constitution of the United Kingdom. It's a set of disconnected documents along with unwritten laws and customs.

 

[Feli]

Foot ulcers are super easy:

Arterial wound (bad/no pulses, cool/cold foot) = send for Vascular consult
Venous wound (swelling, medial ankle often) = compress, bit of debride
Pressure (plantar foot, bedsore, or other rub point) = offload
Trauma/infected = debride, irrigate, abx, amputation

Offloading "biomechanics" plantar foot wounds is really simple. It's fairly subjective but very easy. It's typically met heads or heel or tufts of toes or other weightbear areas. You simply move the pressure to behind or beside the pressure bruise/wound area. That is usually custom insoles/boot Rx or initial quick fix with padding felt/etc around area and/or cut out pressured area. Get a good relationship with local orthotist shops and get some 1/4" felt roll or pre-cut pads and go at it. GL

 

[bloxxeeey]

Foot ulcers are super easy:

Arterial wound (bad/no pulses, cool/cold foot) = send for Vascular consult
Venous wound (swelling, medial ankle often) = compress, bit of debride
Pressure (plantar foot, bedsore, or other rub point) = offload
Trauma/infected = debride, irrigate, abx, amputation

Offloading "biomechanics" plantar foot wounds is really simple. It's fairly subjective but very easy. It's typically met heads or heel or tufts of toes or other weightbear areas. You simply move the pressure to behind or beside the pressure bruise/wound area. That is usually custom insoles/boot Rx or initial quick fix with padding felt/etc around area and/or cut out pressured area. Get a good relationship with local orthotist shops and get some 1/4" felt roll or pre-cut pads and go at it. GL

View attachment 394731

How many fellowships did you do to learn that?

 

[Retrograde_Nail]

It’s called common sense. No residency needed

 

[Feli]

How many fellowships did you do to learn that?

Shoot... my assistant could do 90% of the wound care I do - she does about 50% of it with wraps, DME, dsgs, setups. (and other non-wound stuff)
I tell her not to do stuff with sharp instruments/invasive only because of the liability. In reality, she'd be fine doing a lot of that too.

She looked at a XR today for new pt pain central forefoot a year after another local pod's 1st MPJ fusion + Tailor... she said "it looks fused, but they should've shortened the bone behind the 2nd toe." I was like 😳

 

[air bud]

Hey all, I’m an MD hyperbaric and wound doc. Obviously I see a ton of foot ulcers. I’m relatively new and would like to improve my foot biomechanics knowledge. Are there any gold-standard resources you guys use for this?

The achilles tendon is your mortal enemy. It must be lengthened. Flexor tendons are big time jerks. They must be cut, you can do that in clinic.

Glad you are looking into biomechanics - repeat after me: "It is not what I put on the wound, it is what I take off it"

 

[air bud]

Foot ulcers are super easy:

Arterial wound (bad/no pulses, cool/cold foot) = send for Vascular consult
Venous wound (swelling, medial ankle often) = compress, bit of debride
Pressure (plantar foot, bedsore, or other rub point) = offload
Trauma/infected = debride, irrigate, abx, amputation

Offloading "biomechanics" plantar foot wounds is really simple. It's fairly subjective but very easy. It's typically met heads or heel or tufts of toes or other weightbear areas. You simply move the pressure to behind or beside the pressure bruise/wound area. That is usually custom insoles/boot Rx or initial quick fix with padding felt/etc around area and/or cut out pressured area. Get a good relationship with local orthotist shops and get some 1/4" felt roll or pre-cut pads and go at it. GL

View attachment 394731

Feli hates surgery - this is an MIS osteotomy. Local only if health risk. SOLVE THE PROBLEM

 

[Feli]

Feli hates surgery - this is an MIS osteotomy. Local only if health risk. SOLVE THE PROBLEM

I hate surgey on fat sick ppl, yes.

Crazy ppl too.... give them all pads and fantastic insoles and then let them find their way to the nearby associate mill if they want surgery.

 

[BubbaWub]

She looked at a XR today for new pt pain central forefoot a year after another local pod's 1st MPJ fusion + Tailor... she said "it looks fused, but they should've shortened the bone behind the 2nd toe." I was like 😳

Tell your MA she is a natural. Many of the young guns coming out today have to pay 400k for an education like that. She is a lot like myself, on the job training.

I love on the job training myself, just like your MA. I was never trained on total ankle replacements. The fellows coming into our group are pumping them out on lots of people.

I am doing my first total ankle replacement tomorrow after going to a weekend course. I know I am ready, and the patient will love it. I admit I don't do as much surgery as some people here but you can learn a lot from just observing and watching other providers around you.

People like your MA should be celebrated. She sounds too smart for podiatry school, but if that day ever comes, I will gladly write a letter of recommendation.

Thank you

 

[DYK343]

Adhesive felt doesnt work. It just creates more pressure at the borders of the wound margin where we are trying to gain epithelialization. The window edema with felt cutouts is anti epithelialization in my mind. I stopped that awhile ago. TCC is the only offloading I trust.

MIS osteotomies work so well for plantar met wounds. Way better than any felt offloading pad. I havent had a single one fail. Ever. And I do about 1 a week. Obese. Uncontrolled DM. Unhygienic. Terrible candidate. Dont matter. I prescrub that wound with a chlorhexidine scrub brush and rinse with alochol. Then RN does a formal scrub. If high risk I do abx for 24hrs or if im really worried 5 days. Ive had zero problems. 100% chronic wounds healed or at least significantly improved at 7 day follow up.

Felt reverse mortons extensions have been working well for me to heal hallux ulcers well . Understanding hallux limitus and the role of a reverse mortons extension is valuable.

Understanding the P longus and plantar 1st met head ulcers is beneficial

Understanding the TA tendon and 5th met head ulcers is important

Understanding the long flexor tendon for distal toe ulcers is important.

Understanding calcaneal gait for plantar heel ulcers is important.

 

[DYK343]

*Understanding ankle equinus and forefoot ulcers is important.

 

[Retrograde_Nail]

Understanding calcaneal gait for plantar heel ulcers is important.

Calcaneal gait causing recurrent plantar heel ulcers is the bane of my existence.

I've done TCC on these patients and try and get them into diabetic shoes only for it to recur.

I've tried Achilles shortening and FHL tendon transfers on these. Does not work.

I've tried AJ/STJ fusion on these...risky as they can always have infection risk. It works but high risk. I've had a few get infected and then I am removing the nail and doing re-debridement of the fusion sites and compressing with an ex-fix.

What are you doing?

 

[HeySister]

I MIS burr the plantar calc at apex of ulcer. Works over half the time, sometimes doesn't. Definitely worthwhile. It seems absurd but has helped. I've done endoscopic FHL for this, one worked and two made zero difference.

Calcaneal gait causing recurrent plantar heel ulcers is the bane of my existence.

I've done TCC on these patients and try and get them into diabetic shoes only for it to recur.

I've tried Achilles shortening and FHL tendon transfers on these. Does not work.

I've tried AJ/STJ fusion on these...risky as they can always have infection risk. It works but high risk. I've had a few get infected and then I am removing the nail and doing re-debridement of the fusion sites and compressing with an ex-fix.

What are you doing?

 

[josebiwasabi]

I do mis plantar calc exostectomy followed by synthetic fat graft injection. Use steris to hold the fat graft in place and nwb for 4 weeks

TCC vs Static offloading frame is often necessary

 

[Retrograde_Nail]

I MIS burr the plantar calc at apex of ulcer. Works over half the time, sometimes doesn't. Definitely worthwhile. It seems absurd but has helped. I've done endoscopic FHL for this, one worked and two made zero difference.

Nice insight. Makes me feel better and makes me feel I am not crazy that a lot of what I am doing is not working.

 

[Retrograde_Nail]

I do mis plantar calc exostectomy followed by synthetic fat graft injection. Use steris to hold the fat graft in place and nwb for 4 weeks

TCC vs Static offloading frame is often necessary

synthetic fat graft injection? but is this really staying in the tissues? Do you believe it is actually going to stay in the tissues?

 

[DYK343]

synthetic fat graft injection. Use steris to hold the fat graft in place and nwb for 4 weeks

Tell me more. No experience with this. Just told/read that fat pad injections often fail/move like retrograde said.

 

[DYK343]

Nice insight. Makes me feel better and makes me feel I am not crazy that a lot of what I am doing is not working.

Honestly I am pro non hinged AFO for these patients.

Most of mine have not been a good surgical candidate. Definately true as of late. Lots of meth abusers with achilles ruptures.

 

[Retrograde_Nail]

Honestly I am pro non hinged AFO for these patients.

Most of mine have not been a good surgical candidate. Definately true as of late. Lots of meth abusers with achilles ruptures.

Is that going to work on my fatty 300 lb neuropathic diabetics with calcaneal gait? Because I might consider it since I am having issues surgically correcting this.

 

[DYK343]

Is that going to work on my fatty 300 lb neuropathic diabetics with calcaneal gait? Because I might consider it since I am having issues surgically correcting this.

No. But neither does the surgery.

 

[josebiwasabi]

synthetic fat graft injection? but is this really staying in the tissues? Do you believe it is actually going to stay in the tissues?

Tell me more. No experience with this. Just told/read that fat pad injections often fail/move like retrograde said.

If you have minimal dissection with mis technique and then directly backfill that with the fat graft and forcibly keep them offloaded via frame vs TCC (depends on amt of drainage) i think it works. I used full length steris and create a box like shape around the graft to help hold it in place.

My N=4 so not exactly level 1 evidence but so far so good

 

[Retrograde_Nail]

If you have minimal dissection with mis technique and then directly backfill that with the fat graft and forcibly keep them offloaded via frame vs TCC (depends on amt of drainage) i think it works. I used full length steris and create a box like shape around the graft to help hold it in place.

My N=4 so not exactly level 1 evidence but so far so good

what graft are you using?

 

[HeySister]

That is part of the problem with endoscopic FHL. You don't want to prone these patients. It's a tough case to master and you are going to be slow at first.

MIS really seems to work. I don't NWB mine because most do these patients aren't safely capable of that. I don't do offloading frames on them, I've gotten away from that. It's a relatively now risk case in these mega high risk patients. Not yet sure how high their risk of recurrence is

Is that going to work on my fatty 300 lb neuropathic diabetics with calcaneal gait? Because I might consider it since I am having issues surgically correcting this.

 

[Weirdy]

NOW WE'RE TALKIN

 

[josebiwasabi]

what graft are you using?

Leneva

 

[air bud]

NOW WE'RE TALKIN

whoa whoa whoa, lets not make SDN a useful resource. All, please return to bickering

 

[deleted1162946]

Do you guys have any articles or any technique guides for performing a DMO for these plantar metatarsal head ulcerations? I have one that I’ve tried to offload to the best of my ability and still can’t get rid of.

 

[DYK343]

Do you guys have any articles or any technique guides for performing a DMO for these plantar metatarsal head ulcerations? I have one that I’ve tried to offload to the best of my ability and still can’t get rid of.

They are the easiest procedure to perform.
Stab incision.
Insert bur.
Take xray to confirm bur is abutting bone/correct location at metatarsal neck.
Step on peddle to initiate burr rotation.
Valgus or varus hand against the bone to cut thru
Remove burr
Single stitch
5 min or less
Stubborn wound is healed in 1 week. Or at least significantly improved.

Stryker will bring the bus and train you if you want to try on cadaver first.
Or beg Arthrex to fly you to Naples.
Or just put on cowboy boots and get it done.

 

[deleted1162946]

They are the easiest procedure to perform.
Stab incision.
Insert bur.
Take xray to confirm bur is abutting bone/correct location at metatarsal neck.
Step on peddle to initiate burr rotation.
Valgus or varus hand against the bone to cut thru
Remove burr
Single stitch
5 min or less
Stubborn wound is healed in 1 week. Or at least significantly improved.

Stryker will bring the bus and train you if you want to try on cadaver first.
Or beg Arthrex to fly you to Naples.
Or just put on cowboy boots and get it done.

This is kind of what I figured but wanted to make sure I wasn’t missing anything. Thanks

 

[Hybrocure]

I recommend investing in a goniometer

 

[Feli]

This thread now makes me soooo glad I'm not a hospital pod.

The diabetes biggunz rarely do find PP, but what a headache. You guys deserve every dollar you're paid... and more. 🙃

 

[air bud]

They are the easiest procedure to perform.
Stab incision.
Insert bur.
Take xray to confirm bur is abutting bone/correct location at metatarsal neck.
Step on peddle to initiate burr rotation.
Valgus or varus hand against the bone to cut thru
Remove burr
Single stitch
5 min or less
Stubborn wound is healed in 1 week. Or at least significantly improved.

Stryker will bring the bus and train you if you want to try on cadaver first.
Or beg Arthrex to fly you to Naples.
Or just put on cowboy boots and get it done.

It's this easy. Sometimes when only one I will do open with HT blade and sagittal saw. because I think those kits are like 600 bucks....but that was just because I was at a community hospital in the red.

Also and maybe I am doing something wrong, I have found my HT incision healing poorly and leaking bone slurry. Not an issue with metatarsals.

 

[deleted1162946]

It's this easy. Sometimes when only one I will do open with HT blade and sagittal saw. because I think those kits are like 600 bucks....but that was just because I was at a community hospital in the red.

Also and maybe I am doing something wrong, I have found my HT incision healing poorly and leaking bone slurry. Not an issue with metatarsals.

Does this ever just transfer the wound to an adjacent metatarsal?

 

[dtrack22]

Does this ever just transfer the wound to an adjacent metatarsal?

It can. I’ve had a few patients where I end up “chasing” pressure across the lesser metatarsal heads when doing transverse/floating osteotomies. But it’s been a small minority of patients so far.

 

[air bud]

It can. I’ve had a few patients where I end up “chasing” pressure across the lesser metatarsal heads when doing transverse/floating osteotomies. But it’s been a small minority of patients so far.

because of the seemingly minimal consequences, is there are argument to do all lesser met heads?

 

[deleted285117]

Adhesive felt works great for me BTW.... so long as it is on the insole/boot and NOT the foot... saw a doc once apply rubber cement directly to people's feet followed by a crap ton of felt. Seemed ridiculous.

 

[Feli]

Adhesive felt works great for me BTW.... so long as it is on the insole/boot and NOT the foot... saw a doc once apply rubber cement directly to people's feet followed by a crap ton of felt. Seemed ridiculous.

Exactly.... felt is a stop gap to put onto a surg shoe or cam boot or mem foam DM type insole or patient's own insole.

It's merely a bit of an offloading bridge until they can get the real custom DME.
It may actually heal some minor ulcers or pre-ulcers, but it's seldom the definitive plan.

I put adhesive met pads on healthy ppl's foot (tester for the day... before they add one to their shoe insole or PStep or orthotic or whatever). Of course no adhesive on DM or pvd or unhealthy ppl skin. I coulda put that in post #4 above, but I kinda think it's common sense 🙂

 

[deleted1162946]

Exactly.... it's a stop gap to put on a surg shoe or cam boot or patient's insole.

It's merely a bit of an offloading bridge until they can get the real custom DME.
It may actually heal some minor ulcers or pre-ulcers.

I put adhesive met pads on healthy ppl's foot (tester for the day before they add to their shoe insole or PStep or orthotic or whatever). Of course no adhesive on DM or pvd or unhealthy ppl skin. I coulda put that in post #4 above, but I kinda think it's common sense 🙂

So you just send patients for a custom insert to offload the met wounds?

 

[DYK343]

Does this ever just transfer the wound to an adjacent metatarsal?

In cavus feet it does. Did one today where patient has rigid cavus. Had 4th met resected by another surgeon. Was in wound center for 2 years before being referred to me. Did a floating 5th met osteotomy about 9 months ago. Healed in a week. But slowly the 3rd became a problem and I did that one today. The 2nd probably next... But he had 9 months no wound and now just a small wound that will heal. Dude was all in on the procedure today. Couldnt wait.

I told him it was likely to happen. I also told him someday we will likely do the 2nd too. Curious how far it will go.

So you just send patients for a custom insert to offload the met wounds?

Diabetic insoles are shown in literature (and my practice) to prevent wounds but not heal them. Not recommended for offloading an active wound.

 

[Feli]

So you just send patients for a custom insert to offload the met wounds?

Yeah (if it's not osteo), they just get custom DM insoles (or "therapeutic" insoles if non-DM... typically cash pay). The kind with met pad + accomod spot at problematic met head (at discretion of orthotist store). It might be a surg shoe or CAM with DM non-custom insole inside it with some felt arts n crafts on it... just until they can get the custom.

That will work for the vast majority if compliant... add gastroc, osteotomy, met head or ray resect, etc based on progress.
Even if they go on to surgery, they still need those afterwards.
If they aren't compliant, send em to the local hospital DPM 😀

I don't do TALs for forefoot ulcers... way too huge a rupture and/or calc ulcer/callus risk imo. I will just offload forefoot w custom DME and do gastroc +/- met surgery if the DME doesn't fix it. But to each their own. In PP, doing surgery on trainwreck ppl with bad insurance is not a first option. Ever. 🙂

I agree with @DYK343 that xfer met ulcer/pressure after osteotomy/amp is more common in cavus than planus/rectus (but it happens in both). They all need custom insoles preferrably before and absolutely afterward... and some wills till have issues.

 

[deleted1162946]

I’ve been doing the pegassist offloading insert and it’s really not doing anything. Are these just junk?

 

[DYK343]

I think those kits are like 600 bucks..

Surprised they are not more

 

[DYK343]

I’ve been doing the pegassist offloading insert and it’s really not doing anything. Are these just junk?

Garbage in my experience. TCC is the answer.

 

[Feli]

I’ve been doing the pegassist offloading insert and it’s really not doing anything. Are these just junk?

Those are pretty bad... looks good in theory, but very hard to tell where the person's foot sits when actually walking, and the pegs crush down or get lost. They are poor quality imo, and cost is very high. I would guess you have to sell them $30+ for shoe w peg asst?

For quick accomod insole/pad, I just use prefab DM insoles (by themselves in ppl's run shoes... or inside velcro surg shoe or CAM). I can get them for about $3/pr ... sell them for $10 (with 1/4" felt met pad or dancer pad or rev dancer pad or arch pad or heel U-pad or whatever person's issue needs). They are really fast yet allow you to nurture your inner TFP for a half minute while adding the pad. Everybody wins. Again, they're not a panacea... typically just a bridge to real custom DME of some sort.

 

[Feli]

Garbage in my experience. TCC is the answer.

Sir, us modest PP folk can't spend 45min per pt. We don't have a nurse to do those, even MA time is too valuable, and we don't want fiberglass on the floor/chair or to do something where supplies cost nearly what the reimburse is (not a factor if on wRVU and not paying supply cost +/- PA or nurse applies TCC).

I honestly haven't done fiberglass of any kind in the office in a few years (rare bi-valve cast in OR major recons... few times per year for big stuff or trauma pts I don't know/trust) 🙂

 

[deleted285117]

Spenco DM insoles are my secret weapon. For $15 can't beat 'em. Apply the offloading felt on the bottom where indicated and viola!

 

[deleted1162946]

Garbage in my experience. TCC is the answer.

But… it’s just going to come back when you get them out of it eventually right? That’s why I never understood that to be the “gold standard”

 

[DYK343]

Sir, us modest PP folk can't spend 45min per pt. We don't have a nurse to do those, even MA time is too valuable, and we don't want fiberglass on the floor/chair or to do something where supplies cost nearly what the reimburse is (not a factor if on wRVU and not paying supply cost +/- PA or nurse applies TCC).

I honestly haven't done fiberglass of any kind in the office in a few years (rare bi-valve cast in OR major recons... few times per year for big stuff or trauma pts I don't know/trust) 🙂

They take me about 10 minutes or less to put on. Probably 5. But they do have to sit there 20min to harden.

The nurses do put on the soft pads. I just come in and put the fiberglass on.

I do have 6 wound center rooms running at one time so I just fly to the next.