Shoulder narrowing surgery is an effective method for upper torso feminization. It is an operation that involves a linear reduction in the length of the clavicles by removing a segment of it. One of the most common questions by patients considering this surgery is how much length of clavicle bone can be removed. Which essentially means how much outer shoulder width reduction will be seen if they undergo the surgery.
The typical clavicle bone segment removed for most patients is 2.5cms her side. This translates in a near 1:1 ratio to the reduction achieved in bideltoid width. This has been what has been done since the first case and is the minimal amount for any shoulder narrowing surgery. To some degree this is an arbitrary amount as there are no clinical or biomechanical studies that have evaluated how much bone can be safely removed based on its effects on shoulder function
I do increase the amount of clavicle bone removed the taller the patient is. In taller patients I will remove a 3cm bone segment per side. It makes sense that a taller patient will have a longer clavicle length and would need a bit more bone removed to have an equal effect to that of a shorter stature patient.
In reviewing the Orthopedic surgery literature the only corollary information about bone length and shoulder function can be gleaned from that of clavicle fractures. Such fractures, when untreated, do go on to heal but develop shortening of their length. Biomechanical studies indicate that if the amount of clavicle shortening is less than 30% of its total length then no adverse effects on shoulder function will result. With typical clavicle lengths of 13 to 14 cms, removal of a 2.5cms in shoulder narrowing represents less than 20% of its length.
Shoulder narrowing surgery does not have a long history of clinical use. It is an evolving surgical technique where no scientific studies have yet been done. Some information can be gleaned from the extensive history of clavicle fractures and their repair but this is not an exact corollary in many ways. (unilateral vs bilateral, osteotomies vs fractures) To date shoulder narrowing with the techniques described has proven to be a very safe and effective procedure with few complications in my experience.
Dr. Barry Eppley