Diagnostic Values of Tests for Acromioclavicular Joint Pain

Abstract

Background: This prospective study was performed to determine which clinical and imaging tests were most helpful for diagnosing acromioclavicular joint pain. Methods: Of 1037 patients with shoulder pain, 113 who mapped pain within an area bounded by the midpart of the clavicle and the deltoid insertion were eligible for inclusion in the study. Forty-two subjects agreed to participate, and four of them were lost to follow-up. Twenty clinical tests, radiography, bone-scanning, magnetic resonance imaging, and an acromioclavicular joint injection test were performed on all patients. The patients were divided into two groups according to whether they had a ≥50% decrease in pain following the acromioclavicular joint injection. Statistical analysis, including multivariate regression analysis, was performed in order to evaluate the diagnostic effectiveness of the various tests. Results: Acromioclavicular joint pain was confirmed in twenty-eight of the thirty-eight patients. The most sensitive tests were examination for acromioclavicular tenderness (96% sensitivity), the Paxinos test (79%), magnetic resonance imaging (85%), and bone-scanning (82%), but these studies had low specificity. In the stepwise regression model, with the response to the injection used as the dependent variable, bone-scanning and the Paxinos test were the only independent variables retained. Patients with a positive Paxinos test as well as a positive bone scan had high post-test odds (55:1) and a 99% post-test probability of having pain due to pathological changes in the acromioclavicular joint. The likelihood ratio for patients with one negative test and one positive test was indeterminate (0.4:1). Patients with both a negative Paxinos test and a negative bone scan had a likelihood ratio of 0.03:1 for having acromioclavicular joint pain, which basically rules out the disorder. Conclusions: The highly sensitive tests had low specificity, and the highly specific tests had low sensitivity. However, the combination of a positive Paxinos test and a positive bone scan predicted damage to the acromioclavicular joint as the cause of shoulder pain with a high degree of confidence. Level of Evidence: Diagnostic study, Level I-1 (testing of previously developed diagnostic criteria in series of consecutive patients [with universally applied reference "gold" standard]). See Instructions to Authors for a complete description of levels of evidence.

RETRACTED: A new test for acromio-clavicolar pathology

“…16 O'Brien et al reported the test to be 100% sensitive and 96.6% specific 12 ; however, these excellent values have not been reproduced by other authors. 3,8,16 We found the O'Brien test to be positive in 48 out of 58 patients, giving it a sensitivity of 83%. In the cross-body adduction test, the AC joint is also compressed by rotating the scapula into the clavicle.…”

“…Standard radiographs of the AC joint are quite specific (90%), but less sensitive (40%) in detecting AC pathology. 3 Ultrasound examination of the AC joint may be a useful tool, 13 but is not used routinely. In the series presented, ultrasound did show AC joint calcification in 1 patient and a full thickness supraspinatus tear was how AC joint calcification in 1 patient and a full thickness supraspinatus tear was suspected from the ultrasound scan in 2; however, the tears were not confirmed at arthroscopy to excise the distal clavicle.…”

“…3 Unfortunately, AC joint injections can be challenging and up to one-third of injections have been shown to be outside the joint. 17 I did not perform radiographic guidance of our injection site.…”

“…All patients were examined, rotator cuff strength, 11 (graded from 0 to 5), impingement signs, AC joint testing, and palpation. The AC joint was clinically examined for local tenderness and 5 AC joint compressive tests were used in random order, including the cross-body adduction, 9 O'Brien's active compression test, 12 Paxinos test, 3 Jacob's test, 1 and the SAC test described below. Radiographs were ordered and assessed for signs of AC joint and erosion, congruency of the AC joint, and glenohumeral pathology.…”

“…1 The location of pain originating from the AC joint can be diverse 2 and patients are often not able to identify the exact location. In most patients, the pain will be located in an area bounded by the mid-part of the clavicle and the deltoid insertion 3 ; but, the pain has also been shown to radiate to the radial side of the forearm into the thumb. 2 AC joint pathology can occur in isolation, but is often associated with other causes of shoulder pain such as subacromial impingement or rotator cuff pathology.…”