Cross off Parihar. He is lying or simply ignorant regarding ATL.
It is physically impossible to have ATL and not be weaker. Impossible. Shah said the same exact thing to me before my surgery. Afterward he told me the surgery would make my tendon 1 grade weaker.
When you do ATL, you are doing 2 things.
1-Lengthening the tendon, therefore losing tension
2- you are making the tendon thinner, and possibly permanently reducing tendon mass. If they use the "slider" technique, they simply slide a piece of the tendon down. If they use the Z plasty technique, they cut out small pieces of the tendon in a zigzag shape.. Z plasty reduces overall tendon mass
Think of a lever, or a rubber band. There is no way that ATL will not decrease plantar torque.
I agree with everything except that z plasty reduces tendon mass.
Maybe only if you do a huge cut and then connect both of the tendons ends in a straight line.
But if you cut the tendon and then stick bith ends side by side, then tis gap unites with scar tissue and then the overall mass is like before more or less.
Of course, scar tissue isn't as strong and especially as flexible as real tendon but it is still reasonably strong.
But the overall tendon mass remains about the same.
So I think that what you call as slider technique is in the reality the Z plasty technique.
The zigk zagk technique you mentioned is not Z plasty but three cuts doctor's do in the tendon (pecurtaneously, not with open technique like Z plasty) where they indeed stretch the tendon. It is like some partial tendon tearings.
Anyway, I had Z plasty lengthening and it is exactly like what you called slider technique where they cut the tendon in a Z shape and they slide one piece of the tendon down and connects both pieces in the middle. This technique doesn't reduce tendon mass (due to scar tissue been formed between) but that doesn't mean that the tendon doesn't become weaker due to loss of tension.
And thats the biggest by far problem with atl, the loss of tension which is the most important because it has to do with the power that the tendon can exert from gastrocnemius muscle.
Thats why the biggest the tendon lengthening, the worse the tension is and the less the push off power because the more you increase the distamce between tendons and muscles, the less power the tendon can exert.
So, because I don't want to be offtopic, atl should not be used for equinus deformity for LL patients. It is much better to turn back the fixators and correct equinus by loosing 1cm of lengthened height (when you haven't consolidated of course) or if there isn't any other solution (PT etc) to do gastrocnemius recession which is by far easier and with better outcomes than atl.
Don't trust any doctor who tells you that atl won't cause any problem because he is either lying or doesn't know what he is doing.