Osteotomy planning for bone reconstruction the forefoot using PSI (patient specific instruments): does anybody know of a team that is interested in the data and can provide clinical input?

Hi everybody, I’m an SPL alumni computer scientist (back in 2005).
We have done the workup of a clinical case that could be used as a case report for foot surgery. We are searching for a team that could give clinical input and/or wants to use this data for a case report. It seems like osteotomies of the metatarsal are usually performed without any 3D computer aided planning which in some cases can lead to undesirable outcomes.

A quick medical history:
After 3 forefoot surgeries the patient (44 years old) can’t walk any more without having strong pain in the mid-foot area. From all current clinical examinations it seems likely this is a biomechanical problem due to the altered shape of the metatarsal bone. Each surgery performed osteotomy and reorientation of the metatarsal-head.
Here a visual overview of how the metatarsal bone has been changed in the course of 3 surgeries. It can be assumed that the bone positions were physiological before the first reorienting osteotomy.
The 2nd and 3rd metatarsal osteotomies were performed in order to reconstruct the “original anatomy” of the big toe joint. In the 3rd surgery the big toe joint had to be fused (arthrodesis of the first metatarsophalangeal joint). Half a year later, the altered biomechanics already started provoking arthroses in the neighboring joints of the mid-food, probably amplified by the long lever of the fused metatarsal-phalanx bone. This probably makes pain-free walking impossible even with special orthopedically adapted shoes.

In order to analyze and visualize the problem, we have used 3DSlicer to segment the CTs. We then mirrored the contra-lateral side and registered the models.

A pdf with a more detailed summary can be downloaded on this wetransfer link (valid until June 6th 2024, I can upload it again afterwards if needed):

Any ideas, input or forwarding to people working in this area would be great.
Thanks already!

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Maybe the work @evaherbst has been doing with biomechanics could shed some light?

I’m not a doctor. I’m an engineer. I have done some virtual surgical planning for bone surgeries. I think your hypothetical surgical procedure could work, but you may need newer CT data


Thanks @pieper for the heads up.

Kate, this looks very interesting. Are you looking for foot surgeons to assess the feasibility of such a procedure? Or wanting to conduct biomechanical analyses? I work on the shoulder and am not a clinician.

regarding biomechanics, yes, it could be possible to model the different surgeries in biomechanical simulations to test the effects of the reconstructions on the foot biomechanics. This would need detailed knowledge of foot kinematics though.

Mike Rainbow in Canada does some very cool foot kinematics work using biplanar x-ray videos to track bone movement. E.g. see a recent paper from him and Anja Behling here: https://royalsocietypublishing.org/doi/10.1098/rsif.2024.0074


Thanks a lot @piper for connecting! This biomechanical modeling kit is super interesting.

@evaherbst Thanks so much for your link. Yes, I guess right now we are looking mainly for surgical teams who can assess the feasibility of a metatarsal reconstruction surgery.
Our logical conclusion for this specific case is kind of straight forward: since the left foot biomechanically is physiological and right and left foot seem to be very symmetrical → a reconstruction could bring back the original joint articulation. Even though there is a lot we don’t know:

  • the effect of the big toe fusion, even though this usually seems to be successful in persons with an otherwise unchanged foot anatomy
  • how much the altered foot kinematics already has changed ligaments and tendons and therefore bringing back the original shape might not lead to a good result any more.
    But these are all questions for a clinician…
    A kinematic model of the foot in this ArtiSynth Toolkit would be very interesting, unfortunately, it seems not to be publicly available.
    Just if anybody is interested: there is also a group in Heidelberg who work on a project called “3DFoot”: 3D-Foot – MeTKO

@mau_igna_06 Thanks for your thoughts. Yes, we are aware that the CTs are too old at this point. In fact, new CTs have already been taken in March. I heard these kind of planning CTs should not be older than 6 months at the time of surgery, does that sound right?

Thanks a lot for all your answers.

I would say more than 3 months is old but I’m not a doctor

Hi Kate,

Mike Rainbow’s group is working in Artisynth but I do not think their models are openly available.

I also saw this demo:

These sorts of models take a long time to develop - I just wanted to mention Artisynth as a possible tool for investigating the biomechanical effects of such reconstruction surgeries.

Good luck with your project!


Yes, that’s my feeling, too, for this specific problem. But I’m no doctor either…

Hi Eva,
Thanks a lot! Yes, I can imaginge these models must very complex to develop. For this project this is out of reach but maybe this can be put to use in the future!
I’ll give you an update on this specific case, maybe this is of interest to other people, too.
Best, Kate