EBM project – Special Tests for Shoulder Labral Pathologies Yohan Kim Intro: Labral tears of the shoulder labrum can be caused by trauma or repetitive shoulder motion. Mechanisms of trauma include falling onto an outstretched arm or the shoulder, a sudden pull to the shoulder, a sudden upward motion, and a direct blow to the shoulder. Repetitive shoulder motion injuries are often associated with sports injuries that occur from activities such as pitching a baseball, throwing a football or lifting weights. The symptoms that might indicate a labral injury may include a catching sensation, clicking or locking in the shoulder, pain within the joint, increased pain with movement, decreased range of motion of the shoulder and arm, and susceptibility to dislocation. Detecting labral tears in a shoulder can be difficult in a clinical evaluation. It is true that there are methods of detecting such problems. Methods such as arthroscopy and MRI (Magnetic Resonance Imaging) can be used to check and diagnose a patient. Arthroscopy is known to be the most accurate method (gold standard) for diagnosing labrum related pathologies, and MRI can also confirm many diagnoses with a high degree of reliability.1 However, these methods are not very cost efficient. If the results show that the patient does not have the suspected problems, the patient would end up using more money than they should have used for clinical examination. Therefore, it is not easy for patients to decide whether to use these methods or not. In contrast to these methods, diagnostic tests have been developed for the purpose of detecting physical problems without having to go through expensive examinations. By utilizing these tests, it may be possible to help patients avoid unnecessary expenses.1 Out of those diagnostic tests, the anterior apprehension test, the relocation test, and the jerk are tests which have been described for diagnosing labrum related pathologies of the shoulder.1 For the anterior apprehension test, the patient is either in supine or seated position with their test arm abducted to 90 degrees and elbows flexed to 90 degrees. The shoulder is passively moved into maximum external rotation with pressure applied anteriorly.3 A positive outcome for this test is pain and/or apprehension. The relocation test, also known as the Jobe’s test, is usually used after the apprehension test. For this test, the patient is supine with the arm abducted to 90 degrees and elbows flexed to 90 degrees. As the arm is externally rotated, the humeral head is pressed down posteriorly.4 A positive outcome is relief of pain and apprehension when compared to the outcomes of the apprehension test. The jerk test is also carried out with the patient in the supine position. The test arm is abducted 90 degrees and horizontally adducted 90 degrees. An axial load is placed on the humerus while the arm is placed in internal rotation. Then the arm is further adducted horizontally.5 A positive outcome for this test is clicking or clunking accompanied with or without pain. These tests have been used by physicians and athletic trainers for many years. However, most of these tests are only theoretical and have not been tested for their significance in detecting specific symptoms. Nevertheless, they are widely used for diagnosing patients. In order to clarify the true efficiency and reliability of these tests, and to ensure that the medical service providers are using the most effective tests to diagnose patients, further research and comparison of the sensitivity and specificity of the diagnostic tests is needed. In order to further clarify and compare the reliability of the diagnostic tests, research articles have been gathered, compared, and analyzed in order to determine the sensitivity, specificity, positive likelihood ratio and negative likelihood ratio for each test. Statistic comparison results and average for each test: Apprehension Fowler et al. (SLAP) Fowler et al. (Labral Tear) Oh et al. (SLAP) Guanche et al. (Labral Tear) Guanche et al. (SLAP) Average: Sensitivity 28.6 31.6 62 40 30 38.44 Relocation Fowler et al. (SLAP) Fowler et al. (Labral Tear) Sensitivity Specificity 60 35.6 57.9 36.8 Oh et al (SLAP) Guanche et al. (Labral Tear) Guanche et al. (SLAP) Specificity 68.9 70.7 42 87 63 66.32 +LR 0.92 1.08 1.07 3.08 0.81 1.39 -LR 1.04 0.97 0.90 0.69 1.11 0.94 +LR 0.93 0.92 -LR 1.12 1.14 1.04 0.64 1.02 44 44 36 54 87 63 0.96 3.38 0.97 75 59 53.70 40 54 52.91 1.25 1.28 1.38 0.63 0.76 0.91 Sensitivity Specificity +LR 73 36.50 98 Kim et al. 2004 (Labral Tear) 85 5.98 89.7 Nakagawa et al. (Labral Tear) 80 1.25 25 Average: 62.57 87.67 14.58 * +LR: Positive likelihood ratio, -LR: Negative likelihood ratio -LR 0.28 Nakagawa et al. (Labral Tear) Morgan et al.(SLAP) Average: Jerk Kim et al. 2005 (Labral Tear) 0.12 0.94 0.44 Discussion: 1) Apprehension test: A total of three articles had statistics for the anterior apprehension test. They were written by Fowler et al., Oh et al., and Guanche et al. The research carried out by Fowler et al. and Guanche et al. shows that the researchers divided labral pathologies in to two different groups, SLAP(superior labral tear from anterior to posterior) lesion and other labral tears that do not fit into SLAP lesions. The research by Oh et al. focused only on SLAP lesions. Overall average sensitivity of the anterior apprehension test is 38.44 and average specificity is 66.32. The average positive likelihood ratio is 1.39, and the average negative likelihood ratio is 0.94. The statistics indicate that the anterior apprehension test is not very reliable for diagnosing patients. When the statistics are looked at separately, it can be seen that the sensitivity is highest and specificity is lowest in the research by Oh et al. The high sensitivity may be because Oh et al. used subjects who had already undergone arthroscopy and were clinically diagnosed with either a SLAP lesion or other pathologies, whereas the other two studies were carried out on patients before they underwent arthroscopy. The low specificity may be because of the overall age of patients. The subjects Oh et al. recruited had more elderly people (over 40 years old) than younger people (below 40). Further into the article, Oh et al. shows that it is much more difficult to get positive or negative results from patients over 40 years old. This may have resulted in the low specificity. Guanche et al. had the highest specificity out of all the research articles. However, when the patients were diagnosed through arthroscopy, it showed that some patients had more than one of the pathologies. The number of pathologies counted was 152, and the number of labral tears counted was 20. The low number of labral tears compared to other pathologies, and the patients having more than one of the pathologies may be why the specificity was so high for Guanche et al. 2) Relocation test: A total of five articles had statistics for the anterior apprehension test. They were written by Fowler et al., Oh et al., Guanche et al., Nakagawa et al., and Morgan et al. The research carried out by Fowler et al. and Guanche et al. shows that the researchers divided labral pathologies in to either the SLAP lesion group or the labral tears group. The research by Oh et al. and Morgan et al. focused only on SLAP lesions while Nakagawa et al. focused on labral tears. Overall average sensitivity of the relocation test is 53.70 and average specificity is 52.91. The average positive likelihood ratio is 1.38, and the average negative likelihood ratio is 0.91. The statistics show that the relocation test is not very reliable for diagnosing patients. Though there may be many causes to this, one of the reasons may be because the relocation test relies on changes in perceived pain to diagnose patients. In most cases, the patients had more than one of the pathologies. This may have made it much more difficult to make diagnoses. Fowler et al. had the lowest specificity for both SLAP lesion and labral tears. This may be because only 7 patients out of 101 patients had isolated SLAP lesion. The research also says that 72 patients had more than one shoulder pathologies. The high number of patients with multiple pathologies may have created difficulties in accurately diagnosing patients. Guanche et al. had the highest specificity for labral tears. Of all the pathologies recorded, 20 labral tears were recorded from a total of 152 pathologies. When considering the low number of labral tears, this may be why the specificity was so high for Guanche et al. Nakagawa et al. had the highest sensitivity for labral tears. The research mentions that they recruited patients that were all involved in throwing sports and had undergone surgery. Of the 54 patients, 53 were baseball players and 1 of the patients was a javelin thrower. And also, out of 54 patients, 24 had superior labrum injuries and 30 had normal superior labrums. Though the patients did have more than just one of the pathologies, the article does not mention the patients having any other type of labrum related pathologies. Therefore, the patients either had superior labral injuries or had no labral injuries at all. The fact that they played the same sport may also mean that they had the same injuries. These may be the reason for the high sensitivity. 3) Jerk test: A total of three articles had statistics for the jerk test. They were written by Kim et al.(2004), Kim et al.(2005), and Nakagawa et al. All of the research focused on labral tears. Overall average sensitivity of the jerk test is 62.57 and average specificity is 87.67. The average positive likelihood ratio is 14.58, and the average negative likelihood ratio is 0.44. The statistics show that the jerk test is not very reliable for its sensitivity, but it shows promising statistics for its specificity. The research by Kim et al. in 2004 showed the highest percentage for sensitivity. This may have something to do with the patients recruited. The study says that the criteria for recruited patients who have been treated for posteroinferior instability. The posteroinferior instability may have meant more patients with posteroinferior labral pathologies were likely to be recruited. The research by Kim et al. in 2005 showed the highest specificity. Unlike the research in 2004, the subjects recruited 172 patients who have undergone arthroscopic examination at the ‘Samsung Medical Center’. This may explain the lower sensitivity percentage compared to the research done in 2004. The subjects were evaluated through arthroscopy and any abnormal lesions were recorded. The patients identified with posteroinferior labral lesions were divided into two groups. The groups were 1) predominantly posterior, and 2) predominantly inferior. All the subjects, not just the ones with posteroinferior labral lesions, underwent testing through the jerk test. Though there were also patients with superior labral lesions, the research was mainly focused on posteroinferior labral tears. The jerk test was able to identify 22 out of 25 shoulders correctly for posteroinferior labral pathologies, and missed 8 shoulders with positive posteroinferior labral pathologies. All in all, these statistics show that the jerk test may be reliable for identifying negative results. In the case of Nakagawa et al., their research showed the lowest sensitivity of the three articles. This may be because of the type of labral pathologies the patients had. For the two Kim et al. articles, most of the patients had posteroinferior labral pathologies. However, for Nakagawa et al., most of their patients had superior labral pathologies. Out of the 54 patients they recruited, 24 had superior labrum injuries and 30 had normal superior labrums. No patient had posteroinferior labral pathologies. This seems like the reason for the extremely low sensitivity. And for the strangely high specificity, it may be because of the high number of subjects without labral pathologies. More than half of the patients did not have labral pathologies. Conclusion: From the results gathered, it can be said that the apprehension test and the relocation test are not reliable for diagnosing labral pathologies. The jerk test shows promising percentages for specificity and positive likelihood ratio. However, it would be difficult to say that the jerk test would be ideal for diagnosing every type of labral pathology. From the comparison of articles, it seems clear that the jerk test is reliable when it is used for ruling in posteroinferior labral tears. Though there is a possibility for the jerk test to be reliable in ruling out posteroinferior labral tears, further studies seem to be needed to clarify its reliability. Therefore, it would be advised that the jerk test be used for ruling in posteroinferior labral tears, and examiners should not confirm the possibility of posterolateral labral tears based on just the findings from the jerk test. Reference: 1. Kim S-H, Park J-S, Jenong W-K, Shin S-K. 2005. The Kim Test A Novel Test for Posteroinferior Labral Lesion of the Shoulder-A Comparison to the Jerk Test. American Journal of Sports Medicine.33(8):1188–1192. 2. Guanche CA, Jones DC. 2003. Clinical testing for tears of the glenoid labrum. Arthroscopy.19(5):517–523. 3. Joo Han Oh, Jae Yoon Kim, Woo Sung Kim, Hyun Sik Gong, Ji Ho Lee. 2008. The Evaluation of Various Physical Examinations for the Diagnosis of Type II Superior Labrum Anterior and Posterior Lesion. American Journal of Sports Medicine.36(2):353–359. 4. Luime JJ, Verhagen AP, Miedema HS, et al. 2004. Does this patient have an instability of the shoulder or a labrum lesion? JAMA: The Journal Of The American Medical Association.292(16):1989–1999. 5. Kim S, Park J, Park J, Oh I. 2004. Painful jerk test: a predictor of success in nonoperative treatment of posteroinferior instability of the shoulder. American Journal of Sports Medicine.32(8):1849–1855. 6. Nakagawa S, Yoneda M, Hayashida K, Obata M, Fukushima S, Miyazaki Y. 2005. Forced shoulder abduction and elbow flexion test: a new simple clinical test to detect superior labral injury in the throwing shoulder. Arthroscopy: The Journal Of Arthroscopic & Related Surgery: Official Publication Of The Arthroscopy Association Of North America And The International Arthroscopy Association.21(11):1290–1295. 7. Morgan CD, Burkhart SS, Palmeri M, Gillespie M. 1998. Type II SLAP lesions: three subtypes and their relationships to superior instability and rotator cuff tears. Arthroscopy: The Journal Of Arthroscopic & Related Surgery: Official Publication Of The Arthroscopy Association Of North America And The International Arthroscopy Association.14(6):553–565. 8. Fowler EM, Horsley IG, Rolf CG. 2010. Clinical and arthroscopic findings in recreationally active patients. SMARTT: Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology.2:1–8.