The anterolateral complex of the knee: results from the International ALC Consensus Group Meeting

The structure and function of the anterolateral complex (ALC) of the knee has created much controversy since the 're-discovery' of the anterolateral ligament (ALL) and its proposed role in aiding control of anterolateral rotatory laxity in the anterior cruciate ligament (ACL) injured knee. A group of surgeons and researchers prominent in the field gathered to produce consensus as to the anatomy and biomechanical properties of the ALC. The evidence for and against utilisation of ALC reconstruction was also discussed, generating a number of consensus statements by following a modified Delphi process. Key points include that the ALC consists of the superficial and deep aspects of the iliotibial tract with its Kaplan fibre attachments on the distal femur, along with the ALL, a capsular structure within the anterolateral capsule. A number of structures attach to the area of the Segond fracture including the capsule-osseous layer of the iliotibial band, the ALL and the anterior arm of the short head of biceps, and hence it is not clear which is responsible for this lesion. The ALC functions to provide anterolateral rotatory stability as a secondary stabiliser to the ACL. Whilst biomechanical studies have shown that these structures play an important role in controlling stability at the time of ACL reconstruction, the optimal surgical procedure has not yet been defined clinically. Concern remains that these procedures may cause constraint of motion, yet no clinical studies have demonstrated an increased risk of osteoarthritis development. Furthermore, clinical evidence is currently lacking to support clear indications for lateral extra-articular procedures as an augmentation to ACL reconstruction. The resulting statements and scientific rationale aim to inform readers on the most current thinking and identify areas of needed basic science and clinical research to help improve patient outcomes following ACL injury and subsequent reconstruction. Level of evidence V

Coronal alignment after total knee arthroplasty

Recent studies have challenged the long-held notion that neutral mechanical alignment after total knee arthroplasty leads to optimal function and survivorship.The ideal alignment for function and survivorship may actually be different.Kinematic alignment, where components are implanted to re-create the natural flexion/extension axis of the knee, may lead to improved functional results. Residual varus alignment may not adversely impact survivorship provided the tibial component is implanted in neutral alignment

Erratum to: Rotational Laxity Control by the Anterolateral Ligament and the Lateral Meniscus Is Dependent on Knee Flexion Angle: A Cadaveric Biomechanical Study (Clin Orthop Relat Res, 10.1007/s11999-017-5364-z)

© 2017, The Association of Bone and Joint Surgeons®. An error can be found in the author list of the published study, “Rotational Laxity Control by the Anterolateral Ligament and the Lateral Meniscus Is Dependent on Knee Flexion Angle: A Cadaveric Biomechanical Study”. Gillian Corbo’s degree is incorrectly listed as BSc. It should read: “Gillian Corbo MSc”. The change has been made here and above. The authors apologize for the error

Strategies for Reconstruction of the Medial Patellofemoral Ligament

© 2015 Elsevier Inc. The medial patellofemoral ligament (MPFL) has been identified as the main soft tissue restraint to lateral displacement of the patella. It is almost always injured with a patella dislocation, and as such, repair or reconstruction of the MPFL has become a common surgical procedure when treating recurrent patellofemoral instability. This article describes 3 techniques of MPFL reconstruction, with variations based on the method of fixation of the graft to the patella. Meticulous surgical techniques to try to avoid complications and an understanding of when to address some of the predisposing biomechanical factors causing patellofemoral instability should lead to good postoperative function and patient satisfaction

ACL and extra-articular tenodesis

© Springer International Publishing Switzerland 2017. Anterior cruciate ligament reconstruction (ACLR) is one of the most common orthopedic surgical procedures performed. There have been concerns with the inability of an ACLR to reliably restore normal tibial rotation. Various iterations of the lateral extra-articular tenodesis (LET) have been used in an attempt to address anterolateral laxity in an ACL-deficient knee. Initial results with isolated LET were poor in terms of patient satisfaction and subjective clinical testing using a pivot shift test. There is a renewed interest in using LET as an adjunct procedure to a conventional ACLR, as the body of literature looking at a combination procedure has provided more promising results. Our current clinical indications for using LET to augment an ACLR include significant anterolateral laxity (pivot shift grade 2 or greater), young patient age (\u3c20 \u3eyears), genu recurvatum \u3e10°, or participation in a high-risk pivoting sport

Extra-articular plasty with ACL reconstruction: Long-term results of associated procedure

© ISAKOS 2017. The aim of surgical management of the anterior cruciate ligament (ACL)-deficient knee is to restore knee stability, allowing return to activity and preventing secondary injury. Unfortunately, even in the face of technological advances in modern day ACL reconstruction, problems of persistent anterolateral rotational laxity exist. Recent research has therefore focused on the anterolateral structures and hence anterolateral reconstructions as a method to better control rotation. This paper provides an historical perspective on the use of lateral extra-articular reconstruction and where these procedures may be best utilised in todays ACL reconstruction algorithm

Lateral reinforcement in anterior cruciate ligament reconstruction

Lateral extra-articular procedures were popular in the treatment of anterior cruciate ligament injury in the nineteen seventies and eighties, but fell from favor due to poor results, concerns regarding biomechanics, and concurrent advances in intra-articular reconstruction. Persistent problems with rotational control in modern reconstructive techniques have lead to a resurgence of interest in the concept of lateral reinforcement. In this article, we examine the history of lateral extra-articular procedures, the reasons for renewed interest in the technique, recent research that lends support to lateral procedures and possible indications for selective use

Is robotic-assisted unicompartmental knee arthroplasty a safe procedure? A case control study

The hypotheses were that firstly there is few early specific complications due to the use of a robotic-assisted system for unicompartimental knee arthroplasty (UKA), and secondly there are less revisions and complications after robotic-assisted UKA than after conventional UKA

No difference of gait parameters in patients with image-free robotic-assisted medial unicompartmental knee arthroplasty compared to a conventional technique: early results of a randomized controlled trial

PURPOSE: In recent studies, robotic-assisted surgical techniques for unicompartmental knee arthroplasty (UKA) have demonstrated superior implant positioning and limb alignment compared to a conventional technique. However, the impact of the robotic-assisted technique on clinical and functional outcomes is less clear. The aim of this study was to compare the gait parameters of UKA performed with conventional and image-free robotic-assisted techniques. METHODS: This prospective, single-center study included 66 medial UKA, randomized to a robotic-assisted (n?=?33) or conventional technique (n?=?33). Gait knee kinematics was assessed on a treadmill at 6months to identify changes in gait characteristics (walking speed, each degree-of-freedom: flexion-extension, abduction-adduction, internal-external rotation, and anterior-posterior displacement). Clinical results were assessed at 6months using the IKS score and the Forgotten Joint Score. Implants position was assessed on post-operative radiographs. RESULTS: Post-operatively, the whole gait cycle was not significantly different between groups. In both groups, there was a significant improvement in varus deformity between the pre- and post-operative gait cycle. There was no significant difference between the two groups in clinical scores, implant position, revision, and complication rates. CONCLUSION: No difference of gait parameters could be identified between medial UKA performed with image-free robotic-assisted technique or with conventional technique. LEVEL OF EVIDENCE: Prospective randomized controlled trial. Level of evidence I

The role of the meniscotibial ligament in posteromedial rotational knee stability

PURPOSE: Tears of the posterior horn of the medial meniscus (PHMM) are very common in the ACL-deficient knee. Specific lesions of the PHMM have been described in the setting of ACL rupture: ramp lesions and injuries to the meniscotibial ligament. There are little data available regarding the role these lesions play in knee instability. The aim of this study is to analyse the biomechanical consequences of ramp and meniscotibial ligament lesions on knee stability. Our hypothesis was that these lesions would cause increased instability in the setting of ACL rupture. METHODS: A cadaveric study was undertaken: ten knees were included for analysis. The biomechanical repercussions of different meniscoligamentous injuries were studied in four stages: stage 1 involved testing the intact knee, stage 2 after transection of the ACL, stage 3 following creation of a ramp lesion, and stage 4 after detachment of the meniscotibial ligament. Four parameters were measured during the experiment: anterior tibial translation under a force of 134 N, internal and external tibial rotation under a torque of 5 Nm, and valgus angulation under a torque of 10 Nm. Measurements were taken in four knee flexion positions: 0° or full extension, 30°, 70°, and 90° of flexion. RESULTS: There was a statistically significant increase in anterior tibial translation for stage 2 (6.8 ± 1.3 mm, p d 0.001), stage 3 (9.4 ± 1.3 mm, p d 0.001), and stage 4 (9.3 ± 1.3 mm, p d 0.001) compared to stage 1. There was no significant difference between stage 2 and stage 3 (2.6 mm, n.s.) or stage 4 (2.5 mm, n.s.). We did, however, demonstrate an increase in anterior tibial translation of 2.6 mm after the creation on a lesion of the PHMM compared to isolated division of the ACL, for all flexion angles combined. There was an increase in internal tibial rotation between stage 1 and stage 4 (3.2° ± 0.7°, p d 0.001) and between stage 2 and stage 4 (2.0° ± 0.7°, p = 0.023). A significant difference was demonstrated for external rotation under 5 Nm torque between stages 4 and 1 (2.2° ± 0.5°, p d 0.001) and between stages 4 and 2 (1.7° ± 0.5°, p = 0.007) for all knee flexion angles combined. No created lesion had a significant effect on medial laxity under a 10-Nm valgus torque at any degree of knee flexion. CONCLUSION: Lesions of the posterior horn of the medial meniscus are frequent in cases of anterior cruciate ligament rupture. These lesions appear to play a significant role in knee stability. Ramp lesions increase the forces in the ACL, and the PHMM is a secondary restraint to anterior tibial translation. Lesions of the meniscotibial ligament may increase rotatory instability of the knee