AC Joint Separation (Shoulder Separation)

An AC joint separation (shoulder separation) is an injury to the acromioclavicular joint, where the collarbone (clavicle) meets the top of the shoulder blade (acromion). It usually happens from a fall or a direct hit onto the point of the shoulder. Despite the name, it is different from a shoulder dislocation. Dr. Andrew Dold, a board-certified, fellowship-trained sports medicine surgeon in Frisco, Texas, treats AC joint injuries of every grade, from a sling and therapy to suture-button reconstruction.

Who gets an AC separation?

In a population study, AC dislocations occurred in about 1.8 per 10,000 people per year. Men were affected about 8.5 times as often as women, half of the injuries were in people aged 20 to 39, sports were the most common cause and type III was the most common grade.¹

Grades of AC joint injury

AC injuries are graded from I to VI (the Rockwood classification) based on which ligaments are torn and how far the collarbone moves.²

Diagnosis

Dr. Dold examines the shoulder for tenderness, a step-off or bump at the AC joint and whether the collarbone can be pushed back into place. X-rays, sometimes including views of both shoulders, show how far the collarbone has moved and rule out a collarbone fracture.

Treatment without surgery

Type I and II injuries, and most type III injuries, are treated with a sling for comfort, ice, early motion and physical therapy to restore strength and shoulder-blade control. A visible bump may remain, but function is usually good.

For type III injuries, a meta-analysis of 10 studies found no difference between surgery and non-surgical treatment in pain, strength, function scores or arthritis, although surgery restored the position of the joint better.³ A 2026 meta-analysis of randomized trials including types III to V found no difference in function scores at 2 years or more, while some trials favored non-surgical treatment in the early months.⁴ This is why Dr. Dold usually starts with non-surgical care for type III injuries and considers surgery if pain, weakness or shoulder-blade problems persist, or for selected athletes and manual workers.

Surgery

For type IV to VI injuries, and type III injuries that do not improve, Dr. Dold reconstructs the joint using a suture-button technique: strong suture tape is passed through small holes in the collarbone and the coracoid process and secured with buttons, holding the collarbone in position while the ligaments heal. Occasionally, especially for chronic injuries, he adds a tendon graft to reconstruct the coracoclavicular ligaments. You can read more about the AC TightRope suture-button technique on the manufacturer’s website.

Fixing the coracoclavicular ligaments with suspensory devices such as suture buttons had better outcome scores and fewer complications than older plate or wire fixation of the joint in a systematic review of type III injuries.⁵ Compared with the hook plate, suture-button (suspensory loop) fixation produced better function and less pain, but a somewhat higher complication rate, in another meta-analysis.⁶ In a randomized trial, early recovery was faster without surgery than with hook-plate fixation, and results were equal by 6 months, which is why surgery is reserved for the right patients.⁷

Recovery after surgery

Most patients use a sling for several weeks, then begin gradual motion and strengthening. Heavy lifting and contact sports are usually restricted for several months. Dr. Dold will give you a specific plan.

What the research shows

AC separations have been studied in several randomized trials. Here is what they add.

Type III, and even some higher-grade injuries, often do well without surgery

Randomized trials comparing surgery with non-surgical care for type III to V injuries have generally found similar shoulder function at 1 to 2 years, with faster early recovery and return to work in the non-surgical groups. Surgery restores the position of the joint and the appearance of the shoulder better, and a few secondary outcomes favor surgery in some trials. This supports a shared decision based on your sport, job and goals.

Which surgery

When surgery is chosen, suture-button fixation has produced better scores and fewer complications than hook plates, and anatomic reconstructions have the most favorable results. For chronic injuries, reconstruction with a tendon graft is generally recommended. Adding repair of the AC joint capsule improves front-to-back stability. Even with modern techniques, about 1 in 5 patients has some loss of correction or a complication, which is worth knowing before surgery.

Return to sport

Most athletes return to their previous level of sport after AC reconstruction.

Why see Dr. Dold

• Board certified by the American Board of Orthopaedic Surgery, with subspecialty certification in Sports Medicine
• Sports medicine and arthroscopy fellowship at NYU Langone / Hospital for Joint Diseases; orthopedic residency at the University of Toronto
• Fellow of the American College of Surgeons (FACS), the American Academy of Orthopaedic Surgeons (FAAOS), the American Orthopaedic Association (FAOA) and the Royal College of Surgeons of Canada (FRCSC)
• Author of a SLAP repair book chapter (Springer, 2017) and research on shoulder suture anchors (KSSTA, 2013)
• Team physician and surgical consultant to Rugby Canada; has cared for professional athletes from the NFL, NBA, NHL, MLS, PGA Tour and Major League Rugby
• D Magazine Best Doctors (Collin County), 2019–2026 · Rated 4.9 on Google

Frequently asked questions

Research cited on this page

1. Chillemi C, Franceschini V, Dei Giudici L, et al. Epidemiology of isolated acromioclavicular joint dislocation. Emerg Med Int. 2013;2013:171609. PubMed
2. Mazzocca AD, Arciero RA, Bicos J. Evaluation and treatment of acromioclavicular joint injuries. Am J Sports Med. 2007;35(2):316-329. PubMed
3. Tang G, Zhang Y, Liu Y, et al. Comparison of surgical and conservative treatment of Rockwood type-III acromioclavicular dislocation: A meta-analysis. Medicine (Baltimore). 2018;97(4):e9690. PubMed
4. Lameire DL, Cecere M, Chan A, et al. Outcomes After Operative Versus Nonoperative Management of Type III to V Acromioclavicular Joint Dislocations: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Orthop J Sports Med. 2026;14(7):23259671261440812. PubMed
5. Okereke I, Abdelfatah E. Surgical Management of Acute Rockwood Grade III Acromioclavicular Joint Dislocations: A Systematic Review. Cureus. 2022;14(9):e28657. PubMed
6. Arirachakaran A, Boonard M, Piyapittayanun P, et al. Post-operative outcomes and complications of suspensory loop fixation device versus hook plate in acute unstable acromioclavicular joint dislocation: a systematic review and meta-analysis. J Orthop Traumatol. 2017;18(4):293-304. PubMed
7. Canadian Orthopaedic Trauma Society. Multicenter Randomized Clinical Trial of Nonoperative Versus Operative Treatment of Acute Acromio-Clavicular Joint Dislocation. J Orthop Trauma. 2015;29(11):479-487. PubMed
8. Beitzel K, Cote MP, Apostolakos J, et al. Current concepts in the treatment of acromioclavicular joint dislocations. Arthroscopy. 2013;29(2):387-97. PubMed
   A current-concepts review found general agreement on non-surgical care for type I and II injuries and an initial non-surgical trial for most type III injuries.
9. Murray IR, Robinson PG, Goudie EB, et al. Open Reduction and Tunneled Suspensory Device Fixation Compared with Nonoperative Treatment for Type-III and Type-IV Acromioclavicular Joint Dislocations: The ACORN Prospective, Randomized Controlled Trial. J Bone Joint Surg Am. 2018;100(22):1912-1918. PubMed
   In a randomized trial of type III and IV injuries, surgical fixation gave no functional benefit over non-surgical care at 1 year, and non-surgical patients generally recovered faster.
10. Mah JM, Canadian Orthopaedic Trauma Society (COTS). General Health Status After Nonoperative Versus Operative Treatment for Acute, Complete Acromioclavicular Joint Dislocation: Results of a Multicenter Randomized Clinical Trial. J Orthop Trauma. 2017;31(9):485-490. PubMed
    A Canadian multicenter randomized trial found hook plate fixation did not improve general health compared with non-surgical care for complete AC separations.
11. Boström Windhamre H, von Heideken J, Une-Larsson V, et al. No difference in clinical outcome at 2-year follow-up in patients with type III and V acromioclavicular joint dislocation treated with hook plate or physiotherapy: a randomized controlled trial. J Shoulder Elbow Surg. 2022;31(6):1122-1136. PubMed
    A randomized trial of high-grade AC separations found both surgical and non-surgical groups had very good shoulder function at 2 years, with no added benefit from surgery.
12. Chang N, Furey A, Kurdin A. Operative Versus Nonoperative Management of Acute High-Grade Acromioclavicular Dislocations: A Systematic Review and Meta-Analysis. J Orthop Trauma. 2018;32(1):1-9. PubMed
    A meta-analysis of high-grade injuries found no difference in function scores; non-surgical patients returned to work sooner but had more cosmetic deformity.
13. Lara PHS, Lima EBS, Andreoli CV, et al. Functional, Radiological, and Scapular Motion Evaluation of Surgical Versus Nonsurgical Treatment of Type 3 Acromioclavicular Dislocations: A Randomized Controlled Trial With 24 months’ Follow-up. Am J Sports Med. 2026;54(1):118-127. PubMed
    A 2026 randomized trial of type III injuries found similar disability scores and motion with or without surgery, although some secondary outcomes and cosmetic satisfaction favored surgery.
14. Longo UG, Ciuffreda M, Rizzello G, et al. Surgical versus conservative management of Type III acromioclavicular dislocation: a systematic review. Br Med Bull. 2017;122(1):31-49. PubMed
    A review found persistent pain seemed less frequent after surgery, though overall results were similar.
15. Li Y, Cai J, Li P, et al. Suture Button Could Result in More Functional Outcomes Improvement and Pain Relief Than Hook Plate Technique for Treating Acute Acromioclavicular Joint Dislocation: A Systematic Review of Comparative Studies. Arthroscopy. 2024;40(2):553-566. PubMed
    A meta-analysis found suture-button fixation gave better shoulder scores and fewer complications than hook plate fixation for acute separations.
16. Sircana G, Saccomanno MF, Mocini F, et al. Anatomic reconstruction of the acromioclavicular joint provides the best functional outcomes in the treatment of chronic instability. Knee Surg Sports Traumatol Arthrosc. 2021;29(7):2237-2248. PubMed
    A review found anatomic reconstructions, synthetic or biologic, produced the most favorable functional results.
17. Rosso C, Martetschläger F, Saccomanno MF, et al. High degree of consensus achieved regarding diagnosis and treatment of acromioclavicular joint instability among ESA-ESSKA members. Knee Surg Sports Traumatol Arthrosc. 2021;29(7):2325-2332. PubMed
    An international consensus panel favored arthroscopically assisted anatomic reconstruction with a suspensory device for acute injuries, and biologic graft reconstruction for chronic injuries.
18. Borbas P, Churchill J, Ek ET. Surgical management of chronic high-grade acromioclavicular joint dislocations: a systematic review. J Shoulder Elbow Surg. 2019;28(10):2031-2038. PubMed
    For chronic AC separations, reconstruction methods had similar complication rates, and tendon graft reconstruction gave the most favorable results in higher-quality studies.
19. Li Q, Hsueh PL, Chen YF. Coracoclavicular ligament reconstruction: a systematic review and a biomechanical study of a triple endobutton technique. Medicine (Baltimore). 2014;93(28):e193. PubMed
    Comparative studies showed the older modified Weaver-Dunn procedure left more laxity than newer techniques.
20. Jordan RW, Malik S, Bentick K, et al. Acromioclavicular joint augmentation at the time of coracoclavicular ligament reconstruction fails to improve functional outcomes despite significantly improved horizontal stability. Knee Surg Sports Traumatol Arthrosc. 2019;27(12):3747-3763. PubMed
    Adding AC joint repair to coracoclavicular reconstruction improved horizontal (front-to-back) stability in biomechanical and clinical studies.
21. Aliberti GM, Kraeutler MJ, Trojan JD, et al. Horizontal Instability of the Acromioclavicular Joint: A Systematic Review. Am J Sports Med. 2020;48(2):504-510. PubMed
    A review found no consensus on how to diagnose and treat horizontal AC instability, which is often overlooked.
22. Pill SG, Rush L, Arvesen J, et al. Systematic review of the treatment of acromioclavicular joint disruption comparing number of tunnels and graft type. J Shoulder Elbow Surg. 2020;29(7S):S92-S100. PubMed
    Despite newer techniques, about 20% of patients had loss of reduction or a surgical complication after AC reconstruction.
23. Gowd AK, Liu JN, Cabarcas BC, et al. Current Concepts in the Operative Management of Acromioclavicular Dislocations: A Systematic Review and Meta-analysis of Operative Techniques. Am J Sports Med. 2019;47(11):2745-2758. PubMed
    Open and arthroscopic AC reconstruction had similar loss of reduction, complication and revision rates.
24. Velasquez Garcia A, Franco Abache A, Ingala Martini L. Clavicular tunnel widening after coracoclavicular stabilization surgery: a systematic review and meta-analysis. J Shoulder Elbow Surg. 2024;33(3):738-755. PubMed
    Tunnel widening in the collarbone was seen in most patients after coracoclavicular stabilization, more often in chronic cases.
25. Kay J, Memon M, Alolabi B. Return to Sport and Clinical Outcomes After Surgical Management of Acromioclavicular Joint Dislocation: A Systematic Review. Arthroscopy. 2018;34(10):2910-2924.e1. PubMed
    A meta-analysis found a very high rate of return to sport after AC surgery, mostly to the pre-injury level.
26. Cleary BP, Hurley ET, Kilkenny CJ, et al. Return to Play After Surgical Treatment for Acromioclavicular Joint Dislocation: A Systematic Review. Am J Sports Med. 2024;52(5):1350-1356. PubMed
    A 2024 review found most patients returned to their previous level of sport after surgical treatment for AC dislocation.

Medically reviewed by Andrew P. Dold, MD, FAOA, FAAOS, FACS, FRCSC. Last reviewed October 2026. This page is general information, not medical advice. Individual results vary.