Background: Reshaping the shoulders for a less wide and square appearance can only be done by shortening the length of the clavicles. As the clavicle is a horizontally oriented bone, and the only bone in the body that is, it is conceptually straightforward concept that making it shorter in length will directly bring in the shoulders. And while this is true it is not quite as simple as it sounds. While the removal of the bone segment is uncomplicated, bringing the two ends of the cut clavicle together and stabilizing it in a shortened length with plates and screws is more challenging than the bone removal itself.
While the clavicle is a horizontally oriented bone it is not straight. Its lazy s-shape and round cross-sectional shape make the application of bone fixation devices technically demanding.This challenge is magnified over the more common open reduction and internal fixation of clavicle fractures due to the much smaller incisions that are needed for an aesthetic operation and the resultant location where the bone removal has to be done. (at the supraclavicular fossa) The ostectomy site is done at the inner half of the clavicle on the medial end of the straight shaft of the bone.
When removing the bone segment the two curved ends of the clavicle move closer together as a result of the straight shaft becoming shorter. What was once the application of a straight plate across the osteotomy with good straight bone to do so start to encroach on the curved ends of the clavicle. This is unlike the diagram of applying a plate on a bone model in which the bone has not been shortened. This may look this way in clavicle fractures, where the goal is to re-establish the original bone length, but it is different when the goal is a shorter clavicle. The last screw holes on each side of the plate may end up almost off the bone where the quality of bone is less. In other words while we have straight clavicle plates to use they have been designed for fracture stabilization and are not ideal for a reduced clavicle bone length.
The anatomical differences between the male vs female clavicle is also relevant when shortening its length. Studies have shown that the male clavicle is not only longer than a females it has more of curved shape. In right handed individuals the right clavicle is more curved than the left and has greater thickness. In addition almost all individuals have asymmetry in the clavicle lengths that can differ by as much as 10% in length between the two sides. Given that most patients seeking shoulder reduction surgery are transgender, meaning they are genetic males, these clavicle shape characteristics have relevance for application of plate and screws devices to stabilize their shortened lengths.Â
Case Study: This female sought shoulder reduction for upper torso feminization purposes with a clavicle length of 17cms on the left side and 17.7cms on the right side. The right clavicle was not only longer but was more curved.
Under general anesthesia 2.75cms was removed from each side with double plate and screw fixation. A 6 hole 3.5 thick superior plate was used and a 5 hole 2.5mm plate applied on the anterior surface. All screws used were bicortical in length. (18mm to 20mm)
Her intraoperative before and after pictures showed the change in shoulder shape.
Her before and after postop pictures show the improvement in the upright position.
Clavicle reduction osteotomies are uniquely different from clavicle fracture repair in numerous ways. The most important one is that the natural clavicle length is shortened which places the forces on the stabilized osteotomy site to be greater than that in fractures where the goal is to restore its natural length. As a result the use of a single clavicle fracture plate may prove inadequate. For this reason I use double plate fixation as an insurance against potential fixation failure. New plate designs that are better suited to the unique loads on the shortened clavicle will eventually allow for less hardware to be used that is equally effective..
Case Highlights:
1) The clavicle has a curved non-linear shape which is more exaggerated in males than females.
2) In clavicle reduction osteotomies then curves portions of the two ends of the bone are brought closer together…which has implications on plate and screw fixation.
3) Better plate designs are needed to optimally stabilize clavicle reduction osteotomies with the least amount of hardware and plate profiles.
Dr. Barry Eppley
Indianapolis, Indiana