Contralateral knee hyperextension is associated with increased anterior tibial translation and fewer meniscal injuries in the anterior cruciate ligament-injured knee

Abstract

PurposeTo investigate the influence of hyperextension of the contralateral healthy knee on anterior tibial translation (ATT) and the presence of associated injuries in the anterior cruciate ligament (ACL)-injured knee.MethodsA local patient data register containing the surgical and clinical data of patients undergoing ACL reconstruction was analyzed. Patients were divided into groups according to the degree of hyperextension of the contralateral knee: normal (Group A ≤ 0°), mild (Group B 1°–5°), moderate (Group C 6°–10°), and severe (Group D > 10°). The ATT was measured in both knees preoperatively and 6 months postoperatively using the KT-1000 arthrometer. The presence of associated meniscal and cartilage injuries was noted. Using multivariate analysis, Groups B, C, and D were compared with Group A, using this group as a reference.ResultsA total of 10,957 patients were available in the register and 8502 (Group A n = 4335, Group B n = 3331, Group C n = 771, Group D n = 65) were included in the final analysis. Groups B (10.3 mm; 95% CI 0.06–0.042, p < 0.0001) and C (10.6 mm; 95% CI 0.23–0.89, p = 0.006) showed significantly greater preoperative ATT in the injured knee compared with the control group (10.1 mm). Moreover, at the 6-month follow-up, greater ATT was observed for Groups B (8.5 mm; 95% CI 0.13–0.45, p < 0.0001), C (8.5 mm; 95% CI 0.02–0.60, p = 0.035), and D (9.1 mm; 95% CI − 0.08–1.77, p = 0.082) compared with Group A (8.2 mm). Meniscal injuries were less frequent in patients with contralateral hyperextension [Group B 903 (27.1%) p < 0.0001, Group C 208 (27.0%) p = 0.0003, and Group D 12 (18.5%), 0.012] compared with the control group [Group A 1479 (34.1%)].ConclusionContralateral knee hyperextension is associated with greater pre- and postoperative ATT in the ACL-injured knee. In patients with contralateral knee hyperextension, concomitant injuries to the menisci are less frequent. Surgeons should consider grafts with superior properties regarding postoperative anteroposterior laxity to patients with contralateral knee hyperextension.Level of evidenceRetrospective cohort study, Level IV

Association of Ligamentous Laxity, Male Sex, Chronicity, Meniscal Injury, and Posterior Tibial Slope With a High-Grade Preoperative Pivot Shift: A Post Hoc Analysis of the STABILITY Study

“…An increase in knee hyperextension has been shown to result in an increase in anterior tibial translation. 46 As patholaxity associated with the pivot shift is essentially an anterolateral subluxation, an increase in anterior tibial translation will accentuate the phenomenon-hence, the reason why posteromedial meniscal lesions are also associated with increased pivot. Patients with passive knee hyperextension remain a challenging cohort for surgeons performing ACL reconstructions.…”

Generalized joint hypermobility in siblings with anterior cruciate ligament injuries and matched unrelated healthy siblings

“…The contralateral measure was used for the injured knees when the range of extension differed from the uninjured side. Contralateral measures of extension are considered to better represent the preinjury status of the ACL‐injured side (Sundemo et al, ).…”