Injuries and Medical Advice

Fixing Your AC Joint

A normal shoulder on the left and, right, one with a ruptured AC joint, an injury commonly known as a separated shoulder. While until recently this injury could end a climbing career, a new surgical procedure involving an implant is often successful.


I was skiing and fell onto my shoulder. There is a large lump on top of my shoulder where the collar bone is sticking up. X-rays show that I have damaged my acromioclavicular (AC) joint. Some people suggest surgery while others say it will just heal. What should I do?

—Sam, New Zealand


Here is the issue: Without your AC joint your arm is only attached to your body by muscle and the singular strut—your collar bone—and stability will be lost. This is a fairly common injury among climbers, not because it’s a climbing injury per se, but because climbers tend be a sportingly diverse bunch whose default mode is full tilt.

There are several ligaments that connect the lateral end of the clavicle to the scapula just beneath it, and these restrain the clavicle and control movement at the AC joint. When you crash onto the tip of your shoulder, say when you fly over the handlebars of a bike, these ligaments are vulnerable. For injuries less than complete rupture, the AC joint remains fairly congruous and injury management is conservative. When all ligaments are severed and the AC joint disrupted, the clavicle tends to pop up creating the appearance of a lump, known as a step deformity, or a “separated shoulder.”

When you raise your arm to the side, the first 90 degrees is handled by the glenohumeral joint. The second 90 degrees, from horizontal to beside your head, occur by way of your scapular gliding across your back. This is where the AC articulation becomes a mission critical joint since the clavicle acts like a stabilizing rod, enabling the scapular to move with some sense of functional direction.

The first patient I saw with a ruptured AC joint I promptly referred to a surgeon, assuming they will have a technique for relocating this feckless bone. The surgeon sent him back with a note that said something akin to “Woe is Joe, poor sod. His climbing days are done. Nothing I can do. Soz.” Have you ever tried telling that to a climber? Fat-fucking-chance!

In ye olden days, some surgeons would wire the clavicle back in place. Although reattached, there was little flexibility at the AC joint, which arguably caused just as much trouble. In recent years a new operation with a fancy little implant has been quite successful in both reducing the dislocation back into a normal position while retaining some semblance of flexibility as the ligaments heal. This, Nigel, is your future.

This article appeared in Rock and Ice 247

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