Researchers find pivot apprehension test effective in cases with ACL deficiency
BELFAST, NORTHERN IRELAND — Researchers from the United Kingdom have validated and confirmed the reproducibility of the pivot apprehension test, a knee test like the pivot shift test used to assess an unstable knee and the status of a patient’s ACL.
Unlike the pivot shift test, the pivot apprehension test can be used effectively in awake patients and is not as uncomfortable for them because the test is stopped before the “shift” occurs. Clinicians can make their assessment from the patient’s reaction to the test, Sunny D. Deo, FRCS (Tr&Orth), said in a presentation at the British Orthopaedic Association Annual Congress.
The study Deo and colleagues did in 2008 to validate the pivot apprehension test (PAT) involved 210 patients who underwent the test and had their knees graded 1 to 4 for negative, equivocal, positive or strongly positive, respectively. Then, 81 of those patients underwent knee arthroscopy. Among patients with positive or strongly positive PAT results, 94% had an ACL rupture identified on arthroscopy which yielded a positive predictive value for the PAT of 94%.
In a study the investigators conducted in 2015 to test reproducibility of the PAT, 28 patients (56 knees) underwent 112 PATs. The PAT results, which were blinded, were compared to Lachman test results.
“The PAT did in fact have a strong sensitivity and specificity and therefore a fairly high positive predictive value compared to a Lachman, as well as a good correlation between the two observers,” according to Deo.
“So, we would suggest that PAT is a useful indicator of ACL deficiency. It avoids painful shifting [and] has a high positive predictive value greater than Lachman alone. It is reproducible and teachable and has good sensitivity. So, I urge you to use apprehension and not shift in your clinics,” Deo said. – by Susan M. Rapp
Deo SD, et al. Paper #646. Presented at: British Orthopaedic Association Annual Congress; Sept. 13-16, 2016; Belfast, Northern Ireland.Disclosure: Deo reports no relevant financial disclosures