Increase in rotatory knee laxity seen in patients with partial and complete ACL tears
Patients with partial or complete ACL tears and those who had failed ACL reconstruction had increased rotary knee laxity, according to results of a recently published prospective, multicenter study.
“Patients with partial ACL tears, those with complete ACL tears and those who had undergone a failed ACL reconstruction demonstrated progressively increased rotatory laxity as defined by an increased side-to-side difference in lateral knee compartment translation and acceleration during quantitative pivot shift testing,” Jayson Lian, MD, of the department of orthopedic surgery at the University of Pittsburgh Medical Center and Montefiore Medical Center in New York, and colleagues wrote.
Of the 304 patients in the study, 20 had a partial ACL tear (mean age of 20.7 years; seven were women); 257 had a complete ACL tear (mean age of 24.8 years; 111 were women) and 27 had a failed ACL reconstruction (mean age of 25 years; 18 were women). A sports medicine-trained orthopedic surgeon performed a standardized pivot shift maneuver of the ACL-injured knee and the contralateral healthy knee on all patients prior to the surgical procedure.
Results showed there was a significant difference in rotatory knee laxity in ACL-injured knees and the contralateral healthy knee for lateral knee compartment translation in patients with partial ACL tears (2.2 mm vs. 0.8 mm, respectively), complete ACL tears (3.7 mm vs. 1.2 mm, respectively) and those with failed ACL reconstruction (4.9 mm vs. 1.7 mm, respectively). There was a side-to-side difference in lateral knee compartment translation when comparing patients with partial ACL tears (1.4 mm) and complete ACL tears (2.5 mm), and when compared to patients with partial ACL tears (1.4 mm) and those with failed ACL reconstruction (3.3 mm) and in lateral knee compartment acceleration compared to those with partial ACL tears (0.7 m/s2) and those with complete ACL tears (2.3 m/s2).
Researchers noted rotatory knee laxity was significantly greater in those who underwent a failed ACL reconstruction compared to those with partial ACL tears.
“The results from this study may be helpful when considering indications for the management of high-grade rotatory knee laxity,” the researchers wrote. “Future research will assess the clinical outcome in patients with low- and high-grade rotatory knee laxity.” – by Erin T. Welsh
Disclosures: Lian reports no relevant financial disclosures. Please see the study for other authors’ relevant financial disclosures.