Conservative treatment of a Rockwood IV acromioclavicular joint dislocation, a case report

I. Beijk1 A.J. de Vries2 J. Dening3 J.J.A.M. van Raaij2 M.S. Sietsma2 1 Department of Orthopaedic Surgery, Medisch Spectrum Twente, Enschede, the Netherlands 2 Department of Orthopaedic Surgery, Martini Hospital, Groningen, the Netherlands 3 Department of Radiology, Martini Hospital, Groningen, the Netherlands

Corresponding Author: I. Beijk, iris.beijk@kpnmail.nl

Acromioclavicular joint dislocation is an upcoming problem because of the popularization of sports such as cycling and skiing. This case report describes a young patient with a rare type of AC luxation: Rockwood type IV. With this type of luxation, in most cases, surgery is recommended. This case shows that the decision for conservative treatment was made after the evidently prosperous clinical course. Showcasing that surgery is not always necessary, meaning conservative treatment can be successful and can lead to a quick and satisfactory recovery.

Introduction Injuries to the acromioclavicular (AC) joint are common and occur mostly in young athletes during sports, such as skiing and cycling, and in collision sports.1 Considering the increase in popularity of this kind of sport activities, more AC joint dislocations have been seen in recent years.2 The injury is often the result of a direct fall on the shoulder when the arm is adducted. Indirect trauma, most often caused by a fall on the outstretched arm whereby the humeral head is forced into the joint itself and into the inferior aspect of the acromion, is also common.3,4 Despite the fact that 40% of all shoulder injuries being AC joint dislocations, there is a lack of consensus regarding its treatment, especially in the higher graded AC joint dislocations.5

The severity of AC joint dislocations fit into different classification systems. Rockwood et al.6 developed the most widely utilized system, based on six types of injury to the AC joint (I–VI) (figure 1). The types are based on the severity of injury sustained by the AC ligaments and coracoclavicular (CC) ligaments in addition to the supporting tissues that include the delta-trapezial fascia. In type I the ligaments are stretched while in type II the AC ligament is partially ruptured. AC dislocations with a complete rupture of the AC and CC ligaments are classified as a Rockwood type III.3 The majority of AC joint dislocations are these low-grade types (I-III).7 In type IV AC dislocations the AC ligament, the AC joint capsule and the CC ligament are torn, with the distal clavicle displaced posteriorly into or through the musculus trapezius. In type V the clavicle is displaced under the skin. The last type is Rockwood VI, with the clavicle underneath the coracoid. These high-grade dislocations (IV-VI) do not occur frequently; only 1% of AC dislocations are Rockwood type IV.7,8

Figure 1: Rockwood classification (reproduced from Case courtesy of Andrew Murphy, Radiopaedia.org, rID: 72436, with permission)9.

Patient A 23-year-old male had a ski accident in Austria and was injured after falling on his right shoulder. After direct examination at the local hospital with an X-ray, it was concluded that the patient had a Rockwood IV AC joint dislocation. The advice from that local hospital was operative fixation within two weeks. Eight days after the dislocation, the patient was seen in our orthopaedic department. During clinical examination all movements of the shoulder were painful. Neurological and vascular examination of the right upper limb revealed no abnormalities. A shoulder X-ray was done and showed a small dislocation of the clavicle from the scapula cranially (figure 2).

Figure 2: Shoulder X-ray which suggests a luxation with minimal deviation of the lateral clavicle.

Within a week an MRI was made to detect abnormalities in the ligaments. This revealed that the lateral compartment of the clavicle was dislocated cranially and set in the musculus trapezius. A disruption of the acromioclavicular ligament and the coracoclavicular ligament were also seen. This confirmed a Rockwood type IV AC joint dislocation on the patient’s dominant side (right-handed) (figure 3). The patient works as a truck driver - which is relatively physically demanding - and in his spare time he used to participate in car rallies. There were no prior medical comorbidities, and the patient had no known history of shoulder problems.

Figure 3A & B: Figure A shows a coronal view and B shows a sagittal view. A disruption of the AC and CC ligaments is seen. The clavicle is dislocated cranially and set in the m. trapezius.

Intervention During the diagnosing period, the patient was instructed to use a broad arm sling, which he wore for one week. The patient visited the physiotherapist twice during this first period for exercise instructions to start recovery. While waiting on the outcome of the MRI scan and further treatment plans, the clinical situation improved progressively. Given that the successful clinical course so far in these first three weeks and considering that the outcome of a surgical intervention is uncertain, the patient was not inclined to have surgery. We decided jointly not to operate and to continue follow up. In case of unsatisfying outcomes over the longer term we discussed keeping surgical treatment as an option. Comparison When treating AC dislocations, the challenge is determining the need for surgical intervention. In recent years different techniques have been developed and described. Controversy still exists regarding the choice between conservative and surgical treatment and moreover, the timing of surgery when surgery is chosen. For types I and II AC dislocations there is an agreement that conservative treatment is preferred. There is no consensus so far about the best treatment option – operative or non-operative – for type III AC injuries.10 Surgical treatment is generally recommended for Rockwood types IV through VI AC dislocations,11 yet to our knowledge no evidence-based literature exists favouring a specific treatment strategy for these dislocations. There is no consensus on the best surgical method either. Several options are described, including fixation with a clavicular hook plate, K-wire, Bosworth screw, Steinmann pin or direct coracoclavicular ligament repair, or a combination of these options.1,12 Notably, a high rate of complications is associated with these surgical procedures, including hardware failure, AC arthritis and clavicle osteolysis.11 Re-operation to remove hardware must be done in 67.5% of the patients.12 Despite the lack of effectiveness and high complication rates after surgical intervention, conservative treatment for type IV-VI dislocations is rarely chosen. This is partly due to better functional results and less complications in early operative treatment (within three weeks) compared to delayed surgery, with the result that the conservative course is almost never awaited.13 Outcome Eight weeks post-injury the patient was almost pain-free, and many more shoulder movements were possible. Since all ADL activities could be performed without pain, we decided to continue conservative treatment. Four months after the injury the patient visited our department for evaluation. Only heavy lifting at work in the horizontal plane high above the shoulder was painful, but the pain decreased directly after he stopped lifting. There was no nocturnal pain or ADL pain. Car rallying was the only thing the patient could not yet do due to the high pressure on his shoulder from the car seat belt. During clinical examination a small bulge on his right shoulder was seen (figure 4). No limitations in movements were seen (flexion-extension 180-0-60; abduction-adduction 180-0-10; endorotation up to L1, equal to the left side; strengths in all directions, equal to the left side). Overall, the patient was satisfied with this result.

Figure 4A & B: Digital pictures of the patient with a type IV AC dislocation after four months. A: Lateral view. B: Anterior view.

Conclusion This case illustrates that a Rockwood IV should be considered for shoulder injuries, even though the incidence is low and there is hardly anything to see on the X-ray. This report also emphasizes that a surgical intervention in Rockwood type IV dislocations is not always necessary. Conservative treatment can be successful and can result in a rapid and satisfying recovery. In contrast to what is assumed in literature, conservative treatment must be considered, especially given the risks of complications of surgery. The decision for conservative treatment in this case was made after the evidently prosperous clinical course while waiting for diagnostic results. This case adds to the limited literature about treatment options for Rockwood IV dislocations. More research on nonsurgical treatment results in terms of functional outcomes and pain in these injuries must be conducted. The case emphasizes that the choice of treatment for Rockwood type IV dislocations should always be made on a case-by-case basis and through shared decision making with the patient. Disclosure statement None of the authors have anything to disclose. The presented patient agrees with publication of his medical details.

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