I broke my collar bone 6 years ago, and i never had surgery. it significantly shortened the length between my sternum and shoulder (1 inch). ?

Clavicle malunion: When the clavicle heals in a shortened position, it affects the position of the scapula (termed pseudo-winging), thus affecting shoulder function. If the deformity is "significant", corrective osteotomy (re-break bone) may be needed with a bone graft inserted between the cut ends. The goal is to restore the clavicle to the correct length. Consult with a shoulder specialist who has experience.

Malunion: The shortened healing of the clavicle can lead to problems with shoulder mechanics. After seeing a specialist, they may recommend surgery to cut the bone and plate it back in its normal position. If shoulder mechanics are fine and there is no pain, then nothing should be done.

It commonly does: The collar bone or clavicle acts as a strut for the arm. This helps to position the arm in space. It's not a problem being short, unless you have difficulty moving or lifting. Rarely does the clavicle need to be rebroken and fixed.