The Prevalence of Chronic Impingement Syndrome and SLAP Lesion and the Sensitivity of O ’ Brien ’ s Test

Objective: In this study, we aimed to investigate the prevalence of SLAP lesions in patients with chronic impingement syndrome. We also examined the sensitivity of O’Brien’s test. Materials and Methods: The study included 48 patients with a preliminary chronic impingement syndrome diagnosis to whom arthroscopic decompression had been planned. All patients underwent preoperative Neer’s, Hawkins’ and O’Brien’s tests. We performed shoulder arthroscopy on all patients and evaluated chronic impingement syndrome and SLAP lesions. Then, we compared the statistical sensitivities of these tests. Results: The mean age of patients with chronic impingement was 45.8 years (range, 35-69 years). O’brien’s test was positive in 34 (70.8%) of the patients, and Neer’s test and Hawkins’ test were positive in 46 (95.8%) of the patients before shoulder arthroscopy. Shoulder arthroscopy revealed that 44 (91.7%) of 48 patients had subacromial impingement; 32 (66.7%) had SLAP lesions and internal impingement. In chronic impingement syndrome, sensitivity rates were 95.6% for Neer’s test and Hawkins’ test, whereas in internal impingement syndrome and slap lesions, the sensitivity of O’brien’s test was 94.1%. There was no statistical difference between the tests (p>0.05). Conclusion: 72.72% of the patients with chronic impingement syndrome had concomitant SLAP lesions. We suggest that O’Brien’s test should be used with Neer’s and Hawkins’ tests for diagnosis of this condition.


Introduction
One of the common causes of shoulder pain is chronic impingement syndrome [1][2][3][4], which results from compression of the rotator cuff mechanism in between the acromion, coracoacromial ligament, coracoid process and acromioclavicular joint during movements of the glenohumeral joint, especially during flexion and external rotation [5][6][7][8].
Chronic impingement syndrome should be evaluated for external and internal impingement [9,10].A comprehensive

Original Article
EAJM 2012; 44: 149-52 physical examination should be performed, and differential diagnoses should be kept in mind.Neer's and Hawkins' tests are known as the most specific tests for diagnosis [11].However, O'Brien's test is an effective test for labral abnormalities and is also sensitive and specific for acromioclavicular joint abnormalities [12].
In this study, we investigated the frequency of SLAP lesions in patients with chronic impingement syndrome, and we aimed to compare the sensitivity of O'Brien's test to that of Neer's and Hawkins' tests.We conducted this study to show that performing O'Brien's test together with Neer's and Hawkins' tests for the diagnosis of subacromial impingement is important because of the high frequency of SLAP lesions in patients with chronic impingement syndrome.

Materials and Methods
A total of 48 patients with chronic impingement syndrome were included in the study (mean age, 45.8 years; range 35-69).The study group consisted of 26 (54%) male and 22 (46%) female patients.All patients underwent Neer's, Hawkins' and O'Brien's tests prior to shoulder arthroscopy.Neer's test: Preventing scapular rotation with one hand, the arm of the patient is forced to elevate by the other hand at an angle between flexion and abduction.If pain is present, the test is positive.Hawkins' test: The arm of the patient is held at 90 degrees flexion and then forced to rotate internally.If pain is present, the test is positive.O'Brien's test: While the elbow is fully extended, the arm is flexed to 90 degrees and adducted 15 degrees closer to the midline.The patient is asked to maximally internally rotate so that the thumb is pointed downward.Then, the patient is asked to resist the downward force applied to the arm.If pain occurs during resistance and decreases after external rotation to the same position against downward force, the test is positive (Figure 1, 2) [12].
All patients had shoulder arthroscopy in a beach chair position under interscalene block anesthesia.The arthroscope is inserted into the shoulder joint and subacromial bursa to evaluate the presence of SLAP lesions.Arthroscopic subacromial decompression was performed.Osteophytes around the acromioclavicular joint and spurs on the inferior aspect of the acromion were removed, the subacromial bursa was excised and the coracoacromial ligament was transected at its insertion into the acromion.
The results of the three tests were compared by statistical analysis.Descriptive statistics, frequency, percent values, means and standard deviations were used.Data were analyzed using the Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA) version 18.0.Normal distributions of variables were tested by Student's t-test.Statistical significance was set at p<0.05 with a 95% confidence interval.

Discussion
The most common symptom of chronic impingement syndrome is pain and mostly it is located at the anterior part of shoulder.Neer [13], first described the situation in 1972.Neer divides chronic impingement syndrome into two groups: external and internal.Acromioclavicular joint pathologies, osteophytes, acute or chronic bursa inflammation, thickness of the coracoacromial ligament, proximal humeral fracture and structural changes in the acromion (especially type 3 hook acromion) are among the extrinsic compression causes.Primary intrinsic degeneration of rotator cuff tendons, SLAP lesions, labral tears, anterior laxity and instability of the shoulder, posterior capsular contractures and pathologies of the humeral head and glenoid bone are among the causes of internal impingement.
In the diagnosis of chronic impingement syndrome, Neer's and Hawkins' tests are known as the most sensitive tests [12].Neer's test used for chronic impingement syndrome generally gives negative result in athletes with internal impingement [14].
Degeneration of the labrocapsular complex to various degrees at the superior labrum and anterior and posterior attachment points is called a SLAP lesion [15].O'Brien's test is a specific test for a SLAP lesion [12].O'Brien [12] stated that the sensitivity and specificity of this test in labral abnormalities are 100% and 98.5%, respectively.Walch et al. [16] reported that the SLAP lesion rate was 71% in 17 patients with internal impingement.McFarland et al. [17] found that the sensitivity and specificity of O'Brien's test in SLAP lesions were 47% and 54%, respectively.Parentis et al. [18] reported that the sensitivity of O'Brien's test was 64% in SLAP lesions.Paley et al. [19] performed arthroscopy in 41 athletes with internal impingement and found posterosuperior abrasion in 84% of them.Fowler [20] evaluated shoulder tests in 101 athletes and found that the sensitivity of O'Brien's test was 64% in the diagnosis of SLAP lesions, and the general accuracy was 54%.He also identified SLAP 2 or SLAP 3 lesions in 51 (50.4%) patients.
In our study, the SLAP lesion rate was 72.72% in patients with chronic impingement syndrome.The sensitivity of O'Brien's test was 94.1%, whereas the sensitivity of Neer's and Hawkins' tests was 95.6%.There was no statistically significant difference among these tests.Presence of SLAP lesions concomitant with chronic impingement syndrome is quite high.We suggest that performing O'Brien's test together with Neer's and Hawkins' tests in patients with chronic impingement syndrome is crucial for identifying SLAP lesions.

Figure 1 .
Figure 1.Patient's arm is flexed to 90 degrees, adducted to 10 degrees to 15 degrees, and maximal internal rotation is made.The patient is told to resist against a downward force.

Figure 2 .
Figure 2. Then the patient is told to maximally supinate the arm, and the maneuver is repeated.