AC joint stabilisation – The Holy grail of Shoulder surgery


Whilst there is little debate on the treatment of type 1&2 (conservative), and type 4-6 (surgery), type 3 injuries continue to present a clinical dilemma. Historically, these fractures were treated conservatively and there are numerous papers to support this approach. With newer advances in arthroscopic techniques, there are growing proponents of early ligament reconstruction, although so far there is no clear evidence of potential benefits.

Athletes, or young active patients involved in heavy overhead lifting are more likely to benefit from early surgery. For others, in line with the available evidence, my preferred treatment is to start with conservative treatment including targeted rehabilitation. The AC joint remains permanently prominent, but is generally stabilised by the fibrous tissue. Most patients can therefore regain full movements and strength in due course. In a small minority of patients with persistent instability after 6 months, I offer surgical stabilisation.

The challenge lies in identifying such patients early who are likely to remain unstable in the longer term. Although no test is 100% sensitive, I have found the “Arm adduction test” to be useful. Once the pain from trauma settles down and patient has regained ROM in around 6 weeks, I assess them in the clinic. With the arm flexed to 90 degrees, if active adduction causes further increase in prominence and instability, in my experience I find these patients will continue to be unstable in the longer term and therefore may benefit from earlier surgical intervention.

Increased prominence and instability in Flexion + Adduction


Surgical techniques have constantly evolved over the years and can be broadly divided as follows:

A) Transacromial or subacromial Stabilisation: This is mostly of historic interest. Hook plates are still used to ‘fix’ the ACJ but since it does not address the fundamental issue to C-C ligament tear, the clavicle usually dislocates as soon as the plate is removed. Most specialist Shoulder surgeons have given up using this plate except in special circumstances.

B) Direct fixation of coracoid to clavicle (eg Bosworth screw): Provides secure initial fixation but loosens or breaks over time, has been largely abandoned.

C) Non anatomic reconstruction using Coraco-acromial ligament (Weaver Dunn repair): This provides an attractive option of using CA ligament to substitute for the torn C-C ligament. Advantage of being native tissue with good strength, but is a non anatomic repair. Still popular as a primary or salvage procedure.

D) Coracoclavicular ligament reconstruction using tendon grafts or synthetic ligaments: This is the current treatment of choice. The main advantage is that it is more anatomic than other methods of repair. Can be performed arthroscopically but it relies on drilling a hole through the coracoid, thus risking a fracture. I therefore favour an open procedure (link to the published surgical technique) in which the graft is looped, rather than drilled through the coracoid.

The choice between synthetic and tendon graft is based on surgeon’s preference. Synthetic grafts today are very strong and reliable but have a risk of osteolysis (1) and can potentially stretch out over time. It also entails a small risk of rejection, being a foreign material. Tendon grafts involve extra morbidity (in case of autograft), but mitigate against the risk of late osteolysis or rejection.

There are many techniques to fix the graft, I personally loop the graft around coracoid and fix it through anatomic footprint of native ligament. Others rely on an interference screw or bicortical screw. Whatever technique is used, postoperative rehabilitation is a very important aspect in achieving success, and participation in competitive sports usually takes around 6 months.

AC joint stabilisation is challenging surgery. Apart from the usual surgical risks, there is also a risk of failure of the ligament reconstruction necessitating further surgery. So far there is no gold standard procedure for these injuries (hence the title of the post!), partly due to huge variation in presentation, but also from the enormous stresses that pass through the ligament during movements of arm, multiplied manifold during sporting activities. Most patients do well with modern surgical techniques, but it is important to thoroughly counsel them before surgery to manage expectations and explain the prognosis.


5 thoughts on “AC joint stabilisation – The Holy grail of Shoulder surgery”

  1. Cameron Brinkman

    First off, thank you for your post. I agree with everything you said, especially the part about how patients should be thoroughly briefed before agreeing to ac joint surgery. I separated my shoulder in 2012 and was told I had a grade 3 separation by the ER radiologist, but the orthopedic surgeon I consulted with said it was a grade 5. I was referred to him by a close family friend and, although his website said that he specialized in sports medicine and shoulders/knees, I now know that he was not up-to-date on these surgeries. In the consult, he told me that since I was an elite athlete (water polo, swimming, sand volleyball and weightlifting) that I would need surgery. However, the only options he told me about were no surgery or the modified weaver-Dunn procedure. After listening to him describe the procedure, it seemed very odd, but not knowing that other procedures existed, I asked him what he thought I should do and would surgery get me back to my pre-injury level of activity. He said that if he were me he would definitely repair the shoulder with surgery so I agreed to the modified weaver Dunn while still in the acute phase of my injury. My surgery was done only 5 days after my injury and I now know that I would have been a prime candidate for a direct ligament repair while the ligaments were still floating around in my shoulder. Unfortunately, I was not told of that option or I would have jumped at it. As it was, he performed a modified weaver-Dunn. Resected my clavicle. Moved my CA ligament and now my shoulder has never been even close to the same as it was. I experience pain every day and can no longer hit a volleyball, throw a water polo ball or lift weights, despite doing over a year of physical therapy after surgery. Needless to say, I’ve been really depressed about this for a long time now, but have tried to stay positive and not give up hope. Which brings me to my question. Is there any way to revise a modified weaver Dunn in a more anatomic way? I currently experience pain at my SC joint, as well as in my AC joint and shoulder. In addition, my shoulder feels way different from my uninjured side. It feels shorter from the clavicle resection and it feels as if it’s being pulled forward most-likely from the ca ligament transfer. I also have scapular winging on that side now and heterotopic ossification from the clavicle to the coracoid. Also, my shoulder looks disfigured when compared to my other side. You can tell that the clavicle is shorter on that side and there’s a hole where the end of my clavicle uses to be. Normally I wouldn’t care so much about the way it looks, but I’m an actor so my body is my livelihood. I’m wondering if there’s any revision surgery out there that can help me? I was 23 when I had the surgery and now I’m 31 with a lot of life still in front of me. I’m still in great shape. I eat really healthy and don’t drink or smoke, and feel that my body still has a great potential for healing. I’ve done a lot of research that I wish I would have done prior to agreeing to this surgery, and I’m thinking that maybe reconstructing the joint with a cadaver tendon would help to restore my joint to a more anatomical position. Also, I don’t know if this exists, but do you think modern medicine will ever create an artificial meniscus for the ac joint? It seems like there’s a lot of people out there who, like me, have undergone bad clavicle resections. Many that were unnecessary in the first place. We need something soft, slick and durable that can fill the gap between the distal clavicle and the acromion so the ac joint can properly function again. If you can throw in an artificial ca ligament to replace the one that was snipped and moved to the distal clavicle, that would also be a great innovation, but I’m not holding out much hope for that. Maybe one day soon scientist will be growing new ligaments for the body from a patients own stem cells. Anyway, thank you for reading and if you have any advice for me, I’d really appreciate it. I just want to get my shoulder back on track. I’m so tired of living with this partial disability. I was once a college athlete and exercise/sports were my entire life. I’d love to regain some of my former abilities one day and be able to teach my kids the sports I love.

    1. Thanks for sharing your experience with us. I am sorry to read about all the problems you have had to face. coming to the current status, further treatment depends on two factors
      1. Whether the clavicle is unstable (it is unlikely if you have calcification extending to coracoid)
      2. Disfigurement is due to clavicle being higher (in effect, the joint not being fully reduced)

      This needs to be assessed properly, and if suitable, tendon graft is still an option. Although it may not now reach the pre injury activity levels, it may become cosmetically better to help in your career as an actor.
      Best wishes

      1. Cameron Brinkman

        Dr. Sarda, thank you for your reply. Is it possible to recreate the AC ligaments, as well as the CC ligaments with a tendon graft after the clavicle has already been resected? And in your opinion, don’t you think it’s strange to recommend a modified weaver Dunn surgery for a young athlete with an acute grade 3 separation? From all the research I’ve done it seems like conservative therapy should have been the first step or early repair of the ligaments by means of a hook plate, screw or more modern suspension device. It seems like the weaver Dunn was always used more for older patients with chronic, long-standing pain or more sedentary, non athletic patients? To perform a weaver Dunn on a young athlete still in the early acute phase of the injury, seems extremely wasteful of human anatomy. And to not inform a patient of all the options that were available at the time seems really unethical. I’d understand my surgeons recommendation if no other surgeries for this existed, but it seems to me that even back in 2012, the weaver Dunn was an outdated and inferior surgery with little to no respect for the conservation of natural shoulder anatomy. From my research, it seems like the doctors who still perform this surgery simply do not know how to perform the newer, superior surgeries and instead of telling their patients that and referring them to either a physical therapist or another shoulder specialists, they simply don’t inform them of these superior options so they won’t lose out on the financial gain from performing the surgery themselves. Sorry again for the long comment, but I’d love to hear your thoughts on this? Moreover, after reading through many patient forums, it appears that I’m not the only young person suffering from this surgery or from osteolosis of the distal clavicle or over-resections. Do you think there will ever be a fix or revision to help people like us? I mentioned in my first comment that a surgery that restores the distal clavicle and/or recreates the CA ligament would be ideal. How many years away do you think we are from seeing this kind of surgical technology if you had to ballpark it?

        Thanks again for your time and expertise,

        1. Dear Cameron,
          Management of grade 3 injuries continues to be subject of intense debate to this date. consequently, the advice given to patients with this injury is based on the perceived needs of patient as well as personal beliefs of the surgeon. Medical science continues to evolve and a number of synthetic ligaments are available in the market even now. tendon graft is an option and there is a general consensus that anatomical reconstructions are better than non anatomical ones. To my knowledge, there is no ongoing research into regenerating distal end clavicle, that would essentially mean recreating the joint and I can’t hazard a guess on how long that might take. However, I suggest you see a different shoulder specialist who might be able to help you with a revision surgery if necessary.
          Thanks for your insight and sharing personal experience about this very interesting but complex injury.

          Dr praveen sarda

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