Is conventional radiography still relevant for evaluating the acromioclavicular joint?

Management of acute grade IV and greater acromioclavicular dislocations: Open acromioclavicular brace versus arthroscopic double DogBone® endobutton

INTRODUCTION

Several surgical techniques exist to manage grade IV acute acromioclavicular dislocation (ACD). However, the conventional acromioclavicular brace technique (ACB) has never been compared to the arthroscopic DogBone® (DB) double endobutton technique. The aim of this work was to compare the functional and radiological results of DB stabilization with those of ACB.

HYPOTHESIS

DB stabilization provides similar functional results with a low rate of radiological recurrences compared to ACB.

MATERIAL AND METHODS

This is a case-control study comparing 17 cases of ACD operated by DB (DB group) between January 2016 and January 2021 with 31 cases of ACD operated by ACB (ACB group) between January 2008 and January 2016. The primary outcome was the difference in the D/A ratio (reflecting vertical displacement) measured on an anteroposterior acromioclavicular (AC) X-ray compared between the 2 groups at one-year after surgery. The secondary outcome was a clinical evaluation at one-year using the Constant score and clinical AC instability.

RESULTS

At revision, the mean D/A ratio in the DB and ACB groups was 0.4±0.5 [-0.4-1.6] and 1.6±0.3 [0.8-3.1] respectively (p>0.05). Two patients (11.7%) in the DB group had implant migration with radiological recurrence while 14 patients (33%) had radiological recurrence in the ACB group (p<0.05).

CONCLUSION

The DB technique limits the radiographic recurrence of acute ACD with an equivalent functional result at 1-year postoperatively compared to the conventional ACB technique, which implicitly requires a second operation for hardware removal. The DB technique has become the technique of choice in first-line treatment of acute grade IV ACD.

LEVEL OF EVIDENCE

III; retrospective case-control series.

Sonographic Measurement of Dynamic Horizontal Instability in Acromioclavicular Joint Instability: Description of a Simple Technique and Correlation to Radiographic Parameters

OBJECTIVE

Dynamic horizontal instability is considered to be the main reason for poor outcome after treatment for acromioclavicular (AC) joint instability. In this study, we describe a simple technique to quantify this pathology via sonography.

METHODS

Thirty-six shoulders from 18 patients with ac joint instabilities were examined using modified Alexander views and a standardized sonographic examination. On the Alexander views, overlap of acromion and clavicle (OLAC), glenoid center to posterior clavicle distance (GCPC), and lateral extension (LE) were measured. Afterwards, the results were analyzed and compared with sonography. Posterior translation of the clavicle and the difference of translation between healthy and injured shoulder were evaluated.

RESULTS

The mean age of the patients was 39 ± 14 years (range 19-61 years). We included 4 (22%) Rockwood type 3, 1 (6%) Rockwood type 4, and 13 (72%) Rockwood type 5 lesions. Four (22%) patients were female and 14 (78%) male patients. Posterior clavicle translation of the injured shoulder correlated strongly between OLAC and sonography (r = -0.514, P = .029), and the difference of translation between healthy and injured shoulder correlated very strongly between LE and sonography (r = 0.737, P < .001).

CONCLUSION

The sonographic measurement technique for horizontal instability presented in this work could help detect horizontal instabilities. While the observation of dynamic horizontal displacement is a strength of this technique, measurements are hindered in cases of high coracoclavicular distances.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.