Murrell and Walton evaluated patients with rotator cuff tears to determine which clinical tests were the best for making the diagnosis. The authors are from the University of New South Wales in Australia.
Three test assessment battery:
(1) supraspinatus muscle weakness
(2) weakness of external rotation
(3) positive impingement sign in internal and/or external rotation
where:
• Weakness was defined as a muscle strength score of 0 to 4 on a scale of 0 to 5.
|
Clinical Assessment |
Finding |
Points |
|
supraspinatus muscle |
no weakness |
0 |
|
|
weakness |
1 |
|
external rotation |
no weakness |
0 |
|
|
weakness |
1 |
|
impingement sign on rotation |
negative on both internal and external rotation |
0 |
|
|
positive on internal rotation |
1 |
|
|
positive on external rotation |
1 |
|
|
positive on both internal and external rotation |
1 |
clinical score =
= SUM(points for all 3 tests)
The drop-arm sign has a high predictive value for a torn rotator cuff (98%) but occurs in only 10% of cases.
Interpretation:
• minimum score: 0
• maximum score: 3
• The higher the score and the older the patient, the more likely a torn rotator cuff is present.
|
Clinical Score |
Age in Years |
Post-test Probability for a Torn Rotator Cuff |
|
0 |
any |
0.05 (95% CI 0.02 – 0.11) |
|
1 |
< 40 |
0.25 (0.12 – 0.31) |
|
|
40 - 69 |
0.45 (0.36 – 0.55) |
|
|
>= 70 |
0.76 (0.56 – 0.90) |
|
2 |
< 60 |
0.64 (0.47 – 0.79) |
|
|
>= 60 |
0.98 (0.89 – 1.00) |
|
3 |
any |
0.98 (0.89 – 1.00) |
from page 769
where:
• The pre-test probability is 50% based on the text.
• The table entry for a score of 1 and age of < 40 is "0.12 (0.25 – 0.31)" which is not feasible. The entry above is my guess at the correct value.
Performance:
• The authors claim that the test battery has a predictive value similar to that for MRI and ultrasonography.
Specialty: Surgery, orthopedic
ICD-10: ,
