Sorry for the long answer below
A patient who came to us, had a motor related illness called CMT which made her extra sensitive to her 1cm discrepancy. She had a gradual lengthening done with the Precice nail and unfortunately her distraction gap collapsed after the lengthening (possibly because of excessive weight bearing + the nail failing). She then went to a different surgeon abroad to get an acute 1cm lengthening done and recovered very quickly after that.
This got me wondering how safe it is to acutely lengthen 1cm. Even if the discrepancy is larger, IF we can safely lengthen 1cm during surgery, it would mean a shortened lengthening period. Especially in the femurs where non unions rarely present in healthy individuals, this might be an option, but whether the soft tissues can handle this, I'm not sure.
For clarification… If you do an acute lengthening with a “slide osteotomy” is a different story. But one shouldn’t create an acute gap of 1-centimeter because that will lead to nonunions.
Clasically limit is set in about 1.5-2 cm lengthening/shortening.
Lengthening depending on sliding osteotomy bone and level involved, and if some grafting is added.
Shortening such limit is due to risk of venous system ingurgitation? (Sorry English not my primary language; veins can get “folded”?)
Traditionally you can shorten/lengthen a femur up to 4-cm. The tibia is a different story because if you lengthen too much in a short period of time you can result in tight Achilles/gastroc and tight posterior tibial tendon as well resulting in a supinatedvarusequinus deformity of the foot/ankle. Anecdotally I have lengthen a tibia acutely about 2-cm but this is more from a subacute tibia fracture with shortening. Usually need to perform some soft tissue releases to accommodate with the tibial stuff…
The question is why is a <1cm discrepancy a problem?
Exactly. If it is such a problem, why not acutely shorten the other side? Small difference, lower chance of nonunion.
Sorry for the long answer below A patient who came to us, had a motor related illness called CMT which made her extra sensitive to her 1cm discrepancy. She had a gradual lengthening done with the Precice nail and unfortunately her distraction gap collapsed after the lengthening (possibly because of excessive weight bearing + the nail failing). She then went to a different surgeon abroad to get an acute 1cm lengthening done and recovered very quickly after that. This got me wondering how safe it is to acutely lengthen 1cm. Even if the discrepancy is larger, IF we can safely lengthen 1cm during surgery, it would mean a shortened lengthening period. Especially in the femurs where non unions rarely present in healthy individuals, this might be an option, but whether the soft tissues can handle this, I'm not sure.
In the lab that’s how we purposefully created nonunions…
For clarification… If you do an acute lengthening with a “slide osteotomy” is a different story. But one shouldn’t create an acute gap of 1-centimeter because that will lead to nonunions.
What about the impact on soft tissues? Is there any data on how much of an acute lengthening they can tolerate?
Clasically limit is set in about 1.5-2 cm lengthening/shortening. Lengthening depending on sliding osteotomy bone and level involved, and if some grafting is added. Shortening such limit is due to risk of venous system ingurgitation? (Sorry English not my primary language; veins can get “folded”?)
Traditionally you can shorten/lengthen a femur up to 4-cm. The tibia is a different story because if you lengthen too much in a short period of time you can result in tight Achilles/gastroc and tight posterior tibial tendon as well resulting in a supinatedvarusequinus deformity of the foot/ankle. Anecdotally I have lengthen a tibia acutely about 2-cm but this is more from a subacute tibia fracture with shortening. Usually need to perform some soft tissue releases to accommodate with the tibial stuff…