Between 2009 and 2016, WorkSafeBC accepted almost 1880 claims for acromioclavicular (AC) joint injuries. More than 80% of injured workers were males in the construction, service trades, or transit operator sectors. Only 1% required surgical correction, while others received appropriate rehabilitation. Treatment of type-III (completely displaced) AC joint injuries (Figure) has been controversial. In the 1970s, treatment was generally surgical, and while this has changed to some extent, the debate regarding surgical and nonsurgical treatment persists.
Mechanism of injury
The most common mechanism of AC joint injury is direct trauma to the lateral aspect of the shoulder, when the arm is in an adducted position. The direct force drives the acromion interiorly while the clavicle remains in place, leading to disruption of the acromioclavicular and coracoclivicular ligaments.[1,2,3] Indirect mechanisms of injury resulting from a fall on an outstretched arm or elbow have also been reported.[1,3]
Patients typically present with the injured arm in an adducted and supported position. Pain will localize to the AC joint on palpation and can be accentuated with abduction and cross-body adduction of the arm, though this is usually challenging, given the acuity of the injury. Tenting of the skin may also be present, depending on the degree of displacement. The authors’ practice is to clinically attempt a reduction of the AC joint to help discern a type-III from a type-V injury (Table). Done carefully, this can result in minimal discomfort to the patient.
Radiographs are the initial and frequently only investigations required for AC joint injuries. The anteroposterior (AP), axillary, and Zanca (AP with 10- to 15-degree cephalad tilt) are the recommended views. The AP and Zanca views identify the amount of superoinferior displacement, and the axillary view evaluates anteroposterior displacement. The AP and Zanca views should be performed bilaterally to allow for comparison to the uninjured side.[1,2,3]
AC joint injuries are classified according to the Rockwood Classification (Table).
Management of type-III AC joint injuries
Management of type-III injuries has been controversial, a major reason being the introduction of arthroscopic innovation. Unfortunately, no comparative data on minimally invasive versus nonsurgical management of this injury currently exists. The Canadian Orthopedic Trauma Society performed the most useful randomized controlled trial, which centred on plate fixation versus nonoperative management.[4,5] This study and its follow-up, reported in 2017, failed to show a benefit to the acute surgical management of these injuries. Other studies in this area include a series of patients with AC joint injuries who were treated with hook plate fixation. This series had a small sample size and lacked a comparative nonoperative group.
Several studies have questioned the benefit of hook plate fixation. A retrospective cohort study compared the clinical outcomes between hook plate fixation and conservative management, using quality-of-life measures and patient questionnaires. The operative group consisted of 5 type-III injures and 6 type-V injuries treated with hook plates. The conservative group included 4 type-III and 17 type-V. Mean follow-up time for the surgical group was 32.4 months, and for the conservative group, 34.77 months. No difference was noted in SF36, VAS, DASH, Constant, or Global Satisfaction scores. With radiographic follow-up, a significant difference in persistent AC joint dislocation (100% of the conservative group versus 36.36% of the operative group, P=0.0001) was noted. Despite the difference in radiographic outcome, there seemed to be no difference in functional outcomes.
Several studies support the acute management of AC joint stabilization arthroscopically.[8,9,10] The one major limitation of these studies is the lack of comparison to a nonoperatively treated cohort. Given the superior outcomes following nonsurgical care, caution must be exercised when performing an acute stabilization with an innovative procedure that has not been shown to be superior to nonoperative care.
The most common complications associated with nonsurgical treatment are development of late AC joint arthrosis and persistent instability. Surgical options for these late complications include distal clavicle resection and ligament reconstruction, depending on the exact complaint and degree of displacement. Identifying the correct patient for chronic AC joint reconstruction remains a challenge.
At this time, evidence supports the nonsurgical treatment of acute type-III AC joint injury. Although significant innovation toward minimally invasive techniques has been made, the literature supporting its use is lacking.
For assistance with an injured worker patient with a type-III AC joint injury, please contact a medical advisor in your nearest WorkSafeBC office.
—Ben Jong, MD
Resident, UBC Department of Orthopaedic Surgery
—Danny P. Goel, MD, MSc, FRCSC
WorkSafeBC Visiting SpecialistClinical Associate Professor,UBC Department of Orthopaedic Surgery
This article is the opinion of WorkSafeBC and has not been peer reviewed by the BCMJ Editorial Board.
4. Canadian Orthopaedic Trauma Society. Multicenter randomized clinical trial of nonoperative versus operative treatment of acute acromio-clavicular joint dislocation. J Orthop Trauma 2015;29:479-487.
5. Mah JM, Canadian Orthopaedic Trauma Society (COTS). General health status after nonoperative versus operative treatment for acute, complete acromioclav-icular joint dislocation. J Orthop Trauma 2017;31:485-490.
7. Natera Cisneros LG, Sarasquete Reiriz J. Acute high-grade acromioclavicular joint injuries: Quality of life comparison between patients managed operatively with a hook plate versus patients managed non-operatively. Eur J Orthop Surg Traumatol 2017;27:341-350.
8. Menge TJ, Tahal DS, Katthagen JC, Millett PJ. Arthroscopic acromioclavicular joint reconstruction using knotless coracoclavicular fixation and soft-tissue anatomic coracoclavicular ligament reconstruction. Arthrosc Tech 2017;6:e37.
9. Spoliti M, De Cupis M, Via AG, Oliva F. All arthroscopic stabilization of acute acromioclavicular joint dislocation with fiberwire and endobutton system. Muscles Ligaments Tendons J 2014;4:398-403.
10. Pühringer N, Agneskirchner J. Arthroscopic technique for stabilization of chronic acromioclavicular joint instability with coracoclavicular and acromioclavicular ligament reconstruction using a gracilis tendon graft. Arthrosc Tech 2017;6:e175-e181.
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