How Much Shoulder Widening (Clavicle Lengthening) Can Be Safely Achieved?

Q: Dr. Eppley,I had a couple of questions regarding the amount of lengthening and the result prediction/estimate. You had previously mentioned that a patient could get close to 2 inches of overall broadening. On a page on your website ( it is stated that there is about an 80% correlation between widening of the bone and of the soft tissue/deltoid to deltoid measurement.

As for the specifics of my surgery, you said that you could do 2 cm lengthening per side. 80% of 4 cm comes out to 3.2 cm, so about 1.26 inches total. In addition, I measured the surgery prediction before and after photos in multiple spots around the shoulder and factored in my current  bideltoid measurements, and it looks like about 1.13 to 1.26 inches total widening, so a similar result to the above estimate but not close to 2 inches total.

Don’t get me wrong, the after prediction is an improvement. But I wouldn’t want to have an inaccurate idea of what to expect. My questions are: 

1. Am I perhaps missing a factor in play when looking at this, or is that loosely1.26 inch total bideltoid increase a good estimate? I certainly realize each patient can experience different results, but I did have concerns when the numbers didn’t seem to add up to begin with, especially coupled with the fact that they came out to be very close to my own measurements of the picture, which was closer to one inch than two inches

2. Is more than 2 cm lengthening possible or do you think it would significantly increase chances of complications to the point of not being feasible? Perhaps 2.5 cm to 3.0 cm. I read a post on your website ( stating that 2.5 was the upper limit to what you believe would be reasonable. I noticed some minor discrepancies on surgery details on different pages of the website (I imagine due to new data becoming available or your own experience), so I wondered if that 2.5 limit is still your current limit at this time.

A: Understandably you are probably misinterpreting the role of computer imaging. While it is interesting to calculate how much shoulder widening was actually done on the image vs what amount of bone is actually lengthened, which turns out to be a pretty good correlation, that is not the actual purpose of the imaging.

Its role is really to determine what is the minimum threshold for the patient to consider the surgery worthwhile. If what was imaged was the ‘maximum’ amount of lengthening possible, would the surgery be worth it? That is its real role in helping the patient determine whether they would be satisfied. What I want to obviously avoid is to do this surgery and the patient say later that he thought it would be more.

As to what more could be, or what is the maximum lengthening possible. that is really a question of geometry as well as one unknown factor….how much sagittal split lengthening can be done until the bone won’t heal. For example, if a sagittal split bone cut is made 3 cms in length, almost 10mm of bone contact in the middle can be maintained for 2 cm of lengthening of the clavicle. (see attached) This we know is safe/bone will heal. But if the split was made 4 cms in length, for example, the bone lengthening would be 3 cms per side. Would that heal as well as 2 cms lengthening per side….maybe.

Dr. Barry Eppley

Indianapolis, Indiana