Need for option to add a rod clamp in the middle of the rod between two already fixed clamps

[Bader13012]

Sometimes, during surgery, surgeons need to place an additional rod clamp between two already-fixed rod clamps. The current design only allows adding a third clamp in the middle by sliding all clamps sequentially from the end of the stainless rod, which reduces flexibility during operations

[tareko]

I am curious if the team considered designs for two-part clamps, or if there's anyway for a one-part clamp to accomplish this. @aclark17 : Do you have any background on this?

[tareko]

I have a feeling that this will require a 2-part clamp, which is not an exciting idea to me. Surgeons are accustomed to planning the clamps well, but perhaps if we do end up with a 2-part clamp design, it will be only for cases where it is more harmful to the patient to remove the other clamps than to add the 2-part clamp.

Disadvantage of 2 part clamp:

1. More complex printing
2. Need to add another set of parts that we test and monitor when changed

[apopanda]

Can we just add redundant clamps always? Maybe we can figure out a rule like "if there's X amount of space in between two clamps, add one in the middle". If we don't end up using it, we can just cut it off, or just leave it where it is? The plastic is single use anyway. This would require more supplies / printing and is wasteful, but could save us from designing clamps that don't work well

[apopanda]

Another possibility is to make the entire clamp a U shape, with a block in the middle that'd serve as a spacer so the plastic doesn't overbend / break because of the tightening force. Make it a wedge that pushes into the rod, when tightened with the screws. You would slide the clamp from the top, then add the wedge from the side, tighten as normal?

[apopanda]

Quick sketch of how I see it potentially being done

Offset of the hole for the rod to allow for vertical movement and for the wedge to "lock"

[tareko]

This is a great idea! Thank you for doing the work. Can you submit a pull request with your model so we can take a look? Also, note that this model is the old one and I plan on remaking it with the new interface and also a symmetrical model as per issue #6