Laxity measurement of internal knee rotation after primary anterior cruciate ligament rupture versus rerupture

Purpose The aim of the current study was to objectify the rotational laxity after primary anterior cruciate ligament (ACL) rupture and rerupture after ACL reconstruction by instrumented measurement. It was hypothesized that knees with recurrent instability feature a higher internal rotation laxity as compared to knees with a primary rupture of the native ACL. Study design Cross-sectional study, Level of evidence III. Methods In a clinical cross-sectional study successive patients with primary ACL rupture and rerupture after ACL reconstruction were evaluated clinically and by instrumented measurement of the rotational and antero-posterior laxity with a validated instrument and the KT1000®, respectively. Clinical examination comprised IKDC 2000 forms, Lysholm Score, and Tegner Activity Scale. Power calculation and statistical analysis were performed (p value < 0.05). Results 24 patients with primary ACL rupture and 23 patients with ACL rerupture were included. There was no significant side-to-side difference in anterior translation. A side-to side difference of internal rotational laxity ≥ 10° was found significantly more frequent in reruptures (53.6%) compared to primary ruptures (19.4%; p < 0.001). A highly significant relationship between the extent of the pivot-shift phenomenon and side-to-side difference of internal rotation laxity could be demonstrated (p < 0.001). IKDC 2000 subjective revealed significantly better scores in patients with primary ACL tear compared to patients with ACL rerupture (56.4 ± 7.8 vs. 50.8 ± 6.2; p = 0.01). Patients with primary ACL tears scored significantly better on the Tegner Activity Scale (p = 0.02). No significant differences were seen in the Lysholm Score (p = 0.78). Conclusion Patients with ACL rerupture feature significantly higher internal rotation laxity of the knee compared to primary ACL rupture. The extend of rotational laxity can be quantified by instrumented measurements. This can be valuable data for the indication of an anterolateral ligament reconstruction in ACL revision surgery.

Severe bicompartmental bone bruise is associated with rotatory instability in anterior cruciate ligament injury

Purpose The presence and severity of bone bruise is more and more investigated in the non-contact anterior cruciate ligament (ACL) injury context. Recent studies have advocated a correlation between bone bruise and preoperative knee laxity. The aim of the present study was to investigate the correlation between bone bruise and preoperative rotatory knee laxity. Methods Twenty-nine patients (29.1 ± 9.8 years) with MRI images at a maximum of 3 months after ACL injury (1.6 ± 0.8 months) were included. The bone bruise severity was evaluated according to the International Cartilage Repair Society (ICRS) scale for lateral femoral condyle, lateral tibial plateau, medial femoral condyle, and medial tibial plateau. The intraoperative rotational knee laxity was evaluated through a surgical navigation system in terms of internal–external rotation at 30° and 90° of knee flexion (IE30, IE90) and internal–external rotation and acceleration during pivot-shift test (PS IE, PS ACC). The KOOS score was also collected. The association between ICRS grade of bone bruise and rotational laxity or KOOS was investigated. Results Significant correlation (p < 0.05) was found between the bone bruise severity on the medial tibial plateau and rotational laxity (IE90, PS IE, and PS ACC) and between the severity of bone bruise on femoral lateral condyle and KOOS-Symptoms sub-score. The presence of bone bruise on the medial tibial plateau was significantly associated with a lateral femoral notch sign > 2 mm (very strong odds ratio). No kinematical differences were found between none-to-deep and extensive-generalized lateral bone bruise, while higher IE30 and IE90 were found in extensive-generalized bicompartmental bone bruise than isolated extensive-generalized lateral bone bruise. Conclusion A severe bicompartmental bone bruise was related to higher rotatory instability in the intraoperative evaluation of ACL deficient knees. The severity of edema on the medial tibial plateau was directly correlated with higher intraoperative pivot shift, and the size of edema on the lateral femoral condyle was associated with lower preoperative clinical scores. Level of evidence Level II.

Using the Remnant Anterior Cruciate Ligament to Improve Knee Stability: Biomechanical Analysis Using a Cadaveric Model

Background: Injured anterior cruciate ligament (ACL) tissue retains proprioceptive nerve fibers, vascularity, and biomechanical properties. For these reasons, remnant ACL tissue is often preserved during the treatment of ACL injuries. Purpose: To assess through a cadaveric model whether reorienting and retensioning the residual ACL via an osteotomy improves knee stability after partial ACL tear, with substantial remnant tissue and intact femoral and tibial attachments. Study Design: Controlled laboratory study. Methods: In 8 adult cadaveric knees, we measured anterior tibial translation and rotational laxity at 30° and 90° of flexion with the ACL in its native state and in 3 conditions: partial tear, retensioned, and ACL-deficient. The partial-tear state consisted of a sectioned anteromedial ACL bundle. Results: In the native state, the translation was 10 ± 2.7 mm (mean ± SD) at 30° of flexion and 8.4 ± 3.6 mm at 90° of flexion. Anterior translation of the knees in the partial-tear state (14 ± 2.7 mm at 30° and 12 ± 2.7 mm at 90°) was significantly greater than baseline ( P < .001 for both). Translation in the ACL-retensioned state (9.2 ± 1.7 mm at 30° and 7.2 ± 2.1 mm at 90°) was significantly less than in the ACL-deficient state ( P < .001 for both), and translation was not significantly different from that of the intact state. For ACL-deficient knees, translation (20 ± 4.3 mm at 30° and 16 ± 4.4 mm at 90°) was significantly greater than all other states ( P < .001 for all). Although rotational testing demonstrated the least laxity at 30° and 90° of flexion in the retensioned and intact states and the most laxity in the ACL-deficient state, rotation was not significantly different among any of the experimental states. Conclusion: In a cadaveric model of an incomplete ACL tear, a reorienting and retensioning core osteotomy at the tibial insertion of the remnant ACL improved anteroposterior translation of the knee without compromising its rotational laxity. Clinical Relevance: The findings of this study support the concept of ACL tissue reorienting and retensioning in the treatment of ACL laxity as an area for future investigation.

Different anterolateral procedures have variable impact on knee kinematics and stability when performed in combination with anterior cruciate ligament reconstruction

ObjectiveThe optimal anterolateral procedure to control anterolateral rotational laxity of the knee is still unknown. The objective was to compare the ability of five anterolateral procedures performed in combination with anterior cruciate ligament reconstruction (ACLR) to restore native knee kinematics in the setting of a deficient anterior cruciate ligament (ACL) and anterolateral structures.MethodsA controlled laboratory study was performed using 10 fresh-frozen cadaveric whole lower limbs with intact iliotibial band. Kinematics from 0° to 90° of flexion were recorded using a motion analysis three-dimensional (3D) optoelectronic system, allowing assessment of internal rotation (IR) and anteroposterior (AP) tibial translation at 30° and 90° of flexion. Joint centres and bony landmarks were calculated from 3D bone models obtained from CT scans. Intact knee kinematics were assessed initially, followed by sequential section of the ACL and anterolateral structures (anterolateral ligament, anterolateral capsule and Kaplan fibres). After ACLR, five anterolateral procedures were performed consecutively on the same knee: ALLR, modified Ellison, deep Lemaire, superficial Lemaire and modified MacIntosh. The last three procedures were randomised. For each procedure, the graft was fixed in neutral rotation at 30° of flexion and with a tension of 20 N.ResultsIsolated ACLR did not restore normal overall knee kinematics in a combined ACL plus anterolateral-deficient knee, leaving a residual tibial rotational laxity (p=0.034). Only the ALLR (p=0.661) and modified Ellison procedure (p=0.641) restored overall IR kinematics to the normal intact state. Superficial and deep Lemaire and modified MacIntosh tenodeses overconstrained IR, leading to shifted and different kinematics compared with the intact condition (p=0.004, p=0.001 and p=0.045, respectively). Compared with ACLR state, addition of an anterolateral procedure did not induce any additional control on AP translation at 30° and 90° of flexion (all p>0.05), except for the superficial Lemaire procedure at 90° (p=0.032).ConclusionIn biomechanical in vitro setting, a comparison of five anterolateral procedures revealed that addition of either ALLR or modified Ellison procedure restored overall native knee kinematics in a combined ACL plus anterolateral-deficient knee. Superficial and deep Lemaire and modified MacIntosh tenodeses achieved excellent rotational control but overconstrained IR, leading to a change from intact knee kinematics.Level of evidenceThe level-of-evidence statement does not apply for this laboratory experiments study.

A biomechanical comparison of the main anterolateral procedures used in combination with anterior cruciate ligament reconstruction

Background: None of the anterolateral procedures used in combination with ACL reconstruction (ACLR) to control rotational laxity have demonstrated superiority. The objective was to compare the capacity of the main anterolateral procedures associated with ACLR to restore intact knee kinematics in case of combined ACL and anterolateral structure injury. Methods: The complete kinematics of 10 cadaveric knees, previously modelled by TDM, were recorded using a 3D Motion Analysis® system. Intact knee kinematics, including internal rotation (IR) of the tibial and anterior-posterior (AP) laxity at 30 and 90° flexion were initially assessed, followed by a sequential section of the ACL and anterolateral complex (ALC) (anterolateral ligament (ALL), ALL capsule and Kaplan fibers). After the ACLR, 5 anterolateral procedures were performed consecutively on the same knee: ALLR; Ellison; Deep Lemaire; Superficial Lemaire; and MacIntosh. The last three procedures were randomized. For each procedure, the graft was fixed in neutral rotation at 30° flexion with a tension of 20 N. Results: ACLR alone did not restore overall knee kinematics when there was an ACL+ALC injury, and resulted in residual rotational laxity of the tibia (p > 0.001). Only the ALLR (p=0.262) and modified Ellison (p=0.081) procedures restored normal global IR kinematics. Superficial/deep Lemaire and MacIntosh procedures resulted in over-constrained kinematic profiles (respectively: p=0.013, p=0.018 and p=0.030). In terms of ACLR, the addition of an anterolateral procedure did not provide additional control over AP translation at 30 and 90° (p > 0.05), exception for the surficial Lemaire procedure at 90° (p = 0.032). Discussion: ACLR alone was not sufficient to restore normal kinematics in ACL and ALC-deficient knees. ALLR and Ellison procedures restored physiological kinematics, unlike the MacIntosh procedure which caused additional control of IR and thereby induced over-constraint. Conclusion: The addition of ALLR or the modified Ellison procedure, which restore intrinsic kinematics, might be useful during primary ACL reconstruction to avoid repeated injury without a risk of over-constraint. The superficial/deep Lemaire and MacIntosh procedures resulted in over-constrained kinetics but provided additional rotation control that could be useful in revision surgery.