High incidence of superficial and deep medial collateral ligament injuries in ‘isolated’ anterior cruciate ligament ruptures: a long overlooked injury

Abstract

Purpose In anterior cruciate ligament (ACL) injuries, concomitant damage to peripheral soft tissues is associated with increased rotatory instability of the knee. The purpose of this study was to investigate the incidence and patterns of medial collateral ligament complex injuries in patients with clinically ‘isolated’ ACL ruptures. Methods Patients who underwent ACL reconstruction for complete ‘presumed isolated’ ACL rupture between 2015 and 2019 were retrospectively included in this study. Patient’s characteristics and intraoperative findings were retrieved from clinical and surgical documentation. Preoperative MRIs were evaluated and the grade and location of injuries to the superficial MCL (sMCL), dMCL and the posterior oblique ligament (POL) recorded. All patients were clinically assessed under anaesthesia with standard ligament laxity tests. Results Hundred patients with a mean age of 22.3 ± 4.9 years were included. The incidence of concomitant MCL complex injuries was 67%. sMCL injuries occurred in 62%, dMCL in 31% and POL in 11% with various injury patterns. A dMCL injury was significantly associated with MRI grade II sMCL injuries, medial meniscus ‘ramp’ lesions seen at surgery and bone oedema at the medial femoral condyle (MFC) adjacent to the dMCL attachment site (p < 0.01). Logistic regression analysis identified younger age (OR 1.2, p < 0.05), simultaneous sMCL injury (OR 6.75, p < 0.01) and the presence of bone oedema at the MFC adjacent to the dMCL attachment site (OR 5.54, p < 0.01) as predictive factors for a dMCL injury. Conclusion The incidence of combined ACL and medial ligament complex injuries is high. Lesions of the dMCL were associated with ramp lesions, MFC bone oedema close to the dMCL attachment, and sMCL injury. Missed AMRI is a risk factor for ACL graft failure from overload and, hence, oedema in the MCL (especially dMCL) demands careful assessment for AMRI, even in the knee lacking excess valgus laxity. This study provides information about specific MCL injury patterns including the dMCL in ACL ruptures and will allow surgeons to initiate individualised treatment. Level of evidence III.

Medial Collateral Ligament Reconstruction for Anteromedial Instability of the Knee: A Biomechanical Study In Vitro

“… 14 , 34 In contrast, evidence is only starting to appear to show that an MCL lesion treated nonsurgically at the time of ACL reconstruction is associated with a markedly increased rate of ACL graft failure, 1 , 2 , 37 and there may be a high incidence of unrecognized MCL lesions with isolated ACL injuries. 40 This suggests that nonsurgical treatment may not be best for all MCL injuries and that it may be timely to reconsider surgical procedures, and their indications for use, to control AMRI. 39 Although it is inappropriate to recommend the clinical use of the AM procedure based solely on a biomechanical study in vitro, this work does suggest questions for clinical research, such as the following: In which cases should AM reconstruction be used?…”

“…2 A review of what had been classified and treated as clinically ''isolated'' ACL injuries discovered that 67% of cases had MCL injuries detected on imaging. 40 The pioneering works on anteromedial (AM) rotatory instability (AMRI) of Slocum and Larson 33 and Kennedy and Fowler 20 reported that, in response to external rotation (ER), the first essential lesion on the medial aspect was a rupture of the deep (capsular) MCL (dMCL), followed by a rupture of the superficial MCL (sMCL) and only then by an ACL rupture. The dMCL passes anterodistally across the joint line toward an AM attachment below the rim of the tibial plateau, 5,26 and it is stretched directly by ER.…”

“… 2 A review of what had been classified and treated as clinically “isolated” ACL injuries discovered that 67% of cases had MCL injuries detected on imaging. 40 …”

A Triple-Strand Anatomic Medial Collateral Ligament Reconstruction Restores Knee Stability More Completely Than a Double-Strand Reconstruction: A Biomechanical Study In Vitro

“…The sMCL graft of the TS reconstruction was placed at the medial femoral epicondyle, 4 which confers isometry. 42 However, the DS graft was placed 5 mm posteriorly, the mean anatomic position of another study 25 on which the original technique 9 was based, so it slackened because of anisometry. Other studies show consistently that the sMCL attachment spreads over the epicondyle, so the anterior fibers tighten with knee flexion, maintaining control of valgus.…”

Determining the Roles of the Anterior Cruciate Ligament, Posterolateral Corner, and Medial Collateral Ligament in Knee Hyperextension Using the Heel-Height Test

“… 1 , 23 While the integrity of the MCL is typically evaluated through applying valgus stress to the knee, injuries to the MCL may be present on magnetic resonance imaging (MRI) in up to 67% of patients with normal valgus physical examination findings. 25 In an attempt to optimize patient outcomes after ACL reconstruction, a thorough review of physical examination and imaging findings should be performed to identify concomitant PLC or MCL injuries.…”