Sorensen AKB, Bak K, Krarup AL, Thune CH, Nygaard M, Jorgensen U, Sloth C, Torp-Pedersen S. J Shoulder Elbow Surg 2007;16:174-180. Abstracted by Matthew P. Mobius M.S., P.T., OCS, Long Island New York.
The authors evaluated epidemiological data of patients presenting to the emergency department following soft tissue injury to the shoulder. The purpose of this study was to try to improve upon early diagnosis of acute rotator cuff lesions following trauma. The use of ultrasound imaging was compared to standard examination techniques, and an attempt was made to correlate factors such as age and injury mechanism with the type and degree of rotator cuff injury.
Inclusion criteria for this study were as follows:
1. Patients between the ages of 18-75 years.
2. Acute shoulder trauma (within 2 weeks) to a previously healthy shoulder. Two-thirds of the injuries were related to falls, 19% were from pulls on the arm, and the remainder were not described. Thirty per-cent occurred during sporting activities.
3. Inability to perform active abduction of the shoulder above 90 degrees during the initial visit to the emergency department. Patients with evidence of fracture, dislocation, previous shoulder injury, or evidence of brachial plexus injury were excluded from this study.
After satisfying the inclusion criteria, patients underwent a standard clinical evaluation including passive and active ROM (scaption, flexion, abduction, extension, internal rotation, external rotation), impingement signs (Neer, Hawkins, painful arc, Jobe), acromioclavicular joint tests (cross body, joint tenderness), biceps tendon tests (Yergason, Speed), and the liftoff test for subscapularis pathology. In addition, the “lag signs” as described by Hertel et al were also evaluated and classified into one of four groups:
1. No lag,
2. Greater than 5 degrees lag.
3. Greater than10 degrees lag.
4. Test impossible due to pain.
All tests were then repeated five minutes following a 10ml injection of Lidocaine into the affected shoulder.
Following initial and post injection testing, the patients were then classified into several groups based on the examiner’s preliminary diagnosis. Patients were classified as having a complete tear of a specific tendon if they had a positive lag sign for that tendon. Patients were classified with partial tears when they had a positive lag sign that disappeared following the Lidocaine injection. If there were no lag signs and at least one impingement test was positive, then traumatic tendonitis/impingement was suspected. Patients were classified as having acromioclavicular (AC) joint pathology when at least one AC joint test was positive.
After all manual examinations were done, the ultrasound examination was performed by an experienced radiologist. A 7 MHz linear transducer was employed for all the examinations. The rotator cuff was evaluated in a multiplanar fashion during neutral and internally rotated positions. Additionally the shoulders were evaluated dynamically during abduction. All tests were then repeated following the injection of a contrast medium. All rotator cuff tears (RCTs) were evaluated by location and severity [either full thickness tear (FTT) or partial thickness tear (PTT)]. All patients with pain, disability, and ultrasonographic evidence of FTT were referred for arthroscopy and rotator cuff repair.
The tests were performed, at a median of 13 days after initial injury, to 104 patients (72 men and 32 women) with a median age of 49 years. In total, 57.7% of the patients had evidence of either PTT or FTT on the ultrasound imaging. Of the 28 patients with suspected FTT who underwent arthroscopy, there was a 96% sensitivity for diagnosing the correct degree of RCT with ultrasonographic evaluation. There were 6 cases of locational irregularities when comparing the ultrasonographic evaluation with the arthroscopic findings.
Clinical examination produced a 45% sensitivity (ability to correctly predict presence of lesions) and 79% positive predictive value (absence of false positive results) as compared to ultrasonographic evaluation. There was no correlational significance in the groups with and without FTT with regard to hand dominance of injured arm, mechanism of injury, or activity at the moment of injury. Age factors were significant in that there was a higher rate of FTT in the 50-59 year old and 60-69 year old age groups as compared to the 30-39, 40-49, and 70-75 age groups.
Although the authors said that their data was “limited”, one year followup ultrasound evaluation was performed and the data suggested that small FTT in younger patients may have some healing potential. Other tears tended not to show the same healing potential. Of the patients diagnosed with PTT, the authors suggested that patients with injuries at the insertion site had a tendency towards healing as opposed to injuries in the tendon substance. Again, this was an empirical observation rather than a conclusion based on specific data.
IAOM Comment:
This study attempts to improve upon existing evaluation paradigms following acute trauma to the shoulder. The authors presented data that suggests that classic clinical evaluation techniques performed manually were not particularly sensitive at predicting the presence of RCT in this population. There seemed to be a tendency to underestimate the severity of the shoulder injury with manual examination, as is shown by the relatively low sensitivity of manual testing as compared to the ultrasonographic testing. They also show data that does seem to validate the use of ultrasonographic evaluation in this population as both sensitive and valid. This may be significant in terms of evaluation costs if compared to the use of the relatively expensive MRI testing.
Mechanism of injury was not a significant predictor of RCT, however, age had a strong correlation with RTC in this population. There was a greater than 50% occurrence of RCT in patients over the age of 50 years, and FTT were present in 50% of patients between the ages of 50-69. But, for those under the age of 40, only 1 in 20 had a full thickness tear of the rotator cuff. This could be significant in terms of our subjective evaluation of patients; age will make certain pathologies more likely. Also, according to ultrasound imaging younger patients (mean age 38 years) were more likely to have rotator cuff partial thickness tears at the insertion site, older folks had mid substance tears.
Several limitations with this study are evident. The lack of use of resistive tests in the evaluation was curious and, to the IAOM trained therapist, incomplete in nature. There is also an inherent assumption that quicker surgical treatment will lead to better overall results. Of course, this may be true in some cases but not in others. Ultimately, if we can better diagnose acute shoulder injuries, then we will be better able to focus on proper treatment at the proper time. However, it is still to be determined what treatment and time of treatment is best for different shoulder injuries.