Compared with other tests, supine Napoleon test better detected subscapularis tears
Researchers found the bear-hug test was the most specific test for subscapularis tears.
In results of a study of 130 patients scheduled to undergo arthroscopic rotator cuff tear repair surgery, the supine Napoleon test was superior to the lift-off, bear-hug and Napoleon tests when used to diagnose subscapularis tendon tears.
Other findings from the study, which was conducted in the Department of Orthopaedic Surgery at Tokushima Red Cross Hospital in Tokushima, Japan, showed the supine Napoleon test (SNT) had the greatest diagnostic value for full-thickness subscapularis tendon tears. Investigators also found the SNT was most able to detect partial tears vs. the other clinical tests they studied.
Patients scheduled for surgery
Yoshitsugu Takeda, MD, PhD, who is chief of the Department of Orthopaedic Surgery at Tokushima Red Cross Hospital, told Orthopedics Today, “In comparison with other clinical tests for subscapularis tears, the SNT had the greatest diagnostic value for full-thickness subscapularis tears, especially detecting small tears because the SNT is more sensitive to detect the small deficit of muscle strength.”
Takeda and his colleagues preoperatively performed the lift-off test, Napoleon test, bear-hug test and SNT to evaluate 98 men and 32 women who were scheduled to undergo arthroscopic rotator cuff repair. For each test, they calculated sensitivity, specificity, accuracy and positive and negative likelihood ratios and compared the ability of the tests to detect partial subscapularis tears. Intraoperatively, the investigators classified the patients’ subscapularis tendon lesions with the Lafosse classification system.
Results showed arthroscopically confirmed subscapularis tears in 40% of shoulders. Among the diagnostic tests, researchers found the SNT was most sensitive for detecting subscapularis tears followed by the bear-hug test. The bear-hug test was the most specific, followed by the SNT and the lift-off test. Although the SNT had the greatest accuracy, positive predictive value and negative predictive value, the bear-hug test had the greatest positive likelihood ratio.
Researchers also found the SNT had the lowest negative likelihood ratio and the bear-hug test had the second lowest negative likelihood ratio. Results showed the Napoleon test had the lowest sensitivity, specificity, accuracy and positive likelihood ratio and the highest negative likelihood ratio among all the diagnostic tests evaluated.
Effective for small tears
“[The SNT] is particularly useful for detecting small tears, because we could detect only less than one-third of small tears with other clinical tests, such as lift-off or belly-press test, but [could detect] two-thirds of small tears with [the SNT],” Takeda said.
Takeda said he and his colleagues are investigating the SNT for its ability to evaluate recovery of subscapularis muscle strength after repair of the subscapularis tendon.
He noted that using a manual muscle test during the SNT might improve its diagnostic value and ability to detect subscapularis tears. Takeda said that, theoretically, the SNT is negative if subscapularis muscle strength is fair in terms of manual muscle testing.
“This may be one of the reasons why we could not detect one-third of our patients with small tears using [the SNT]. So, we could improve the diagnostic value of [the SNT] if we performed manual muscle testing during this test,” Takeda said. – by Casey Tingle
- Takeda Y, et al. Arthroscopy. 2016;doi:10.1016/j.arthro.2016.04.034.
- For more information:
- Yoshitsugu Takeda, MD, PhD, can be reached at Tokushima Red Cross Hospital, Department of Orthopaedic Surgery, 103 Irinokuchi, Komatsushima-cho, Komatsushima, Tokushima 773-8502, Japan; email: firstname.lastname@example.org.
Disclosure: Takeda reports no relevant financial disclosures.