Graft choice in combined anterior cruciate ligament and medial collateral ligament reconstruction

Contribution of the Medial Hamstrings to Valgus Stability of the Knee

Background

Multiligament knee injuries involving the medial side are common. When performing surgical reconstruction, use of the medial hamstrings (HS) as grafts remains controversial in this setting.

Purpose

To determine the role of the medial HS in stabilizing the valgus knee for different types of medial-sided knee injury.

Study Design

Controlled laboratory study.

Methods

A biomechanical study on 10 cadaveric knees was performed. Valgus load (force moment of 10 N/m) was applied at 0°, 30°, and 60° of flexion, and the resultant rotation was recorded using an optoelectronic motion analysis system. Measurements were repeated for 4 different knee states: intact knee, superficial medial collateral ligament (sMCL) injury, deep medial collateral ligament (dMCL) injury, and posterior oblique ligament (POL) injury. For each state, 4 loading conditions (+ loaded; - unloaded) of the semitendinosus (ST) and gracilis (GRA) tendons were tested: ST+/GRA+, ST+/GRA-, ST-/GRA+, and ST-/GRA-.

Results

At 0° of flexion, combined unloading of the ST and GRA (ST-/GRA-) increased valgus laxity on the intact knee compared with the ST+/GRA+ condition (P < .05). For all medial-sided injury states (isolated sMCL; combined sMCL and dMCL; and combined sMCL, dMCL, and POL damage), ST-/GRA- increased valgus laxity at 0° and 30° of flexion versus ST+/GRA+ (P < .05 for all). The absolute value of valgus laxity increased with the severity of medial-sided ligament injury. Isolated ST unloading increased valgus laxity for the intact knee and the MCL-injured knee (combined sMCL and dMCL) at 0° of flexion (P < .05 vs ST+/GRA+). Isolated unloading of the GRA had no effect on valgus knee stability.

Conclusion

The medial HS tendons contributed to the stabilization of the knee in valgus, and this was even more important when the medial side was severely affected (POL damage). This stabilizing effect was greater between 0° and 30°, in which the POL is the main valgus stabilizer.

Clinical Relevance

When deciding on graft selection for multiligament knee injury reconstruction, the surgeon should be aware of the effect of harvesting the medial HS tendon on valgus laxity.

The changing trends of the knee function after anterior and posterior cruciate ligaments reconstruction with all-inside arthroscopy technique

We aimed to summarize the effectiveness and changing trends of reconstruction for the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries using all-inside arthroscope technique. Between May 2013 and May 2019, 29 patients with ACL and PCL ligaments rupture were included. All the patients were male, with a mean age of 25.2±2.9 years. The mean follow-up period was 2.4±0.7 years (Range, 2-4 years). Reconstruction surgery of the ACL and PCL ligaments was performed by using autologous hamstring tendon with all-inside arthroscopy technique. The anterior and posterior drawer test, Lachman test, Pivot-shift test, stress test, IKDC score, Lysholm score, Tenger score were analyzed clinically. At the last follow-up, the symptoms were improved significantly, the anterior drawer test was normal and 1 degree in 96.6%, posterior drawer test in 89.7%, pivot shift test in 96.6%, Lachman test in 93.1%, and stress test in 93.3%, the stability was improved significant(P<0.05). The IKDC-2000 standard score was normal and near normal in 96.6%. The IKDC subjective score, Lysholm score, and Tenger scores results at the last follow-up were significantly improved when compared with those before operation ( P<0.05). The changing trends of function evaluation score in the first six months were most obviously better, especially in the third month. All-inside arthroscopy technique is an effective procedure for the ACL and PCL ligaments injuries, and the first six months (especially the third month) after the reconstruction is the key period for a successful recovery. However, there was still a significant improvement at the later stage of rehabilitation.

Tibial tunnel expansion does not correlate with four-strand graft maturation after ACL reconstruction using adjustable cortical suspensory fixation

PURPOSE

Anterior cruciate ligament reconstruction (ACLR) using a short, quadrupled semitendinosus (ST-4) autograft, fixed  with an adjustable suspensory fixation (ASF), has several potential advantages. However, the construct is suspected to generate micromotion, tunnel widening and poor graft maturation. The aim of this study was to evaluate post-operative tibial tunnel expansion, graft maturation and clinical outcomes for this type of ACLR.

METHODS

One-hundred and forty-nine patients were reviewed at a minimum of 2 years following 4-ST ACLR, mean 25.6 ± 3.5 months [24-55], with clinical follow-up and MRI scans. Graft maturity of the intra-articular part of the graft and the tibial tunnel portion was assessed using Signal-to-Noise Quotient (SNQ) and Howell score. Tibial tunnel expansion, bone-graft contact and graft volume in the tibial tunnel were calculated from the MRI scans.

RESULTS

Mean tibial tunnel expansion was 13 ± 16.5% [12-122]. Mean SNQ for graft within the tibial tunnel was 3.8 ± 7.1 [ - 7.7 to 39] and 2.0 ± 3.5 [ - 14 to 17] for the intra-articular portion of the graft. The Howell score for graft within the tibial tunnel was 41% Grade I, 37% Grade 2, 20% Grade 3, 2% grade 4, and for the intra-articular part 61% Grade 1, 26% Grade 2, 13% Grade 3 and 1% Grade 4. The mean tibial tunnel bone-graft contact was 81 ± 23% [0-100] and mean graft volume was 80 ± 22% [0-100]. No correlation was found between tibial tunnel expansion and graft maturity assessed at both locations. Graft maturity was correlated with higher graft-bone contact and graft volume in the tibial tunnel (p < 0.05).

CONCLUSIONS

ST-4 ACLR with ASF had low levels of tunnel enlargement at 2 years. No correlation was found between graft maturation and tibial tunnel expansion. Graft maturity was correlated with graft-bone contact and graft volume in the tibial tunnel.

LEVEL OF EVIDENCE

Level III.

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

BACKGROUND

There are many descriptions of medial collateral ligament (MCL) reconstruction, but they may not reproduce the anatomic structures and there is little evidence of their biomechanical performance.

PURPOSE

To investigate the ability of "anatomic" MCL reconstruction to restore native stability after grade III MCL plus posteromedial capsule/posterior oblique ligament injuries in vitro.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve cadaveric knees were mounted in a kinematic testing rig to impose tibial displacing loads while the knee was flexed-extended: 88-N anteroposterior translation, 5-N·m internal-external rotation, 8-N·m valgus-varus, and combined anterior translation plus external rotation (anteromedial rotatory instability). Joint motion was measured via optical trackers with the knee intact; after superficial MCL (sMCL), deep MCL (dMCL), and posterior oblique ligament transection; and then after MCL double- and triple-strand reconstructions. Double strands reproduced the sMCL and posterior oblique ligament and triple-strands the sMCL, dMCL, and posterior oblique ligament. The sMCL was placed 5 mm posterior to the epicondyle in the double-strand technique and at the epicondyle in the triple-strand technique. Kinematic changes were examined by repeated measures 2-way analysis of variance with posttesting.

RESULTS

Transection of the sMCL, dMCL, and posterior oblique ligament increased valgus rotation (5° mean) and external rotation (9° mean). The double-strand reconstruction controlled valgus in extension but allowed 5° excess valgus in flexion and did not restore external rotation (7° excess). The triple-strand reconstruction restored both external rotation and valgus throughout flexion.

CONCLUSION

In a cadaveric model, a triple-strand reconstruction including a dMCL graft restored native external rotation, while a double-strand reconstruction without a dMCL graft did not. A reconstruction with the sMCL graft placed isometrically on the medial epicondyle restored valgus rotation across the arc of knee flexion, whereas a reconstruction with a more posteriorly placed sMCL graft slackened with knee flexion.

CLINICAL RELEVANCE

An MCL injury may rupture the anteromedial capsule and dMCL, causing anteromedial rotatory instability. Persistent MCL instability increases the likelihood of ACL graft failure after combined injury. A reconstruction with an anteromedial dMCL graft restored native external rotation, which may help to unload/protect an ACL graft. It is important to locate the sMCL graft isometrically at the femoral epicondyle to restore valgus across flexion.

Complications of surgical reconstruction of multiligament injuries of the knee joint: diagnosis, prevention and treatment

The main complications of surgical reconstruction of multiligament injuries of the knee joint are residual or recurrent instability, arthrofibrosis, popliteal artery injury, common peroneal nerve injury, compartment syndrome, fluid extravasation, symptomatic heterotopic ossification, wound problems and infection, deep venous thrombosis, and revision surgery.

Careful surgical planning and execution of the primary surgical reconstruction of multiligament injuries of the knee joint can minimize the risk of the aforementioned complications.

Careful postoperative follow-up is required to detect complications. Early recognition and prompt treatment are of paramount importance.

To obtain good results in the revision surgery of failed multiligamentary knee reconstructions, it is crucial to perform a thorough and exhaustive evaluation to detect all the causes of failure.

Addressing all associated injuries during revision surgery will lead to the best possible subjective and objective results, although functional outcomes are often modest.

However, advanced age and high-energy injuries have been associated with the poorest functional outcomes after revision surgery of failed multiligament injuries of the knee joint.

Cite this article: EFORT Open Rev 2021;6:973-981. DOI: 10.1302/2058-5241.6.210057

Medial soft-tissue complex of the knee: Current concepts, controversies, and future directions of the forgotten unit

The medial side of the knee is comprised of ligaments, myotendinous and meniscal structures that work as a unit to stabilize the joint. The superficial medial collateral ligament is its core structure. Still, all elements of the medial side have load-sharing relationships, leading to a cascade of events in the scenario of insufficiency of any of them. Understanding the medial soft tissue structures as part of a unit is of utmost importance because the most common ligaments damaged in knee injuries belong to it. Surprisingly, there is a lack of high-level evidence published around the issue, and most studies focus on the superficial medial collateral ligament, overlooking the complexity of these injuries. Acknowledging the consequences for joint biomechanics and treatment outcomes, interest in this area is growing between researchers. Emerging evidence may become a game-changer in the future management of these injuries. Based on a thorough research of published literature, this review provides a current biomechanical concepts and clinical guidance to treat these injuries.

Posterolateral corner knee injuries: a narrative review

Limited knowledge of the anatomy and biomechanics of the posterolateral corner (PLC) of the knee, coupled with poor patient outcomes with non-operative management, resulted in the PLC often being labelled as the ‘dark side’ of the knee. In the last two decades, extensive research has resulted in a better understanding of the anatomy and function of the PLC, and has led to the development of anatomic reconstructions that have resulted in improved patient outcomes.

Despite considerable attention in the clinical orthopaedic literature (nearly 400 articles published in the last decade), a standardized algorithm for the diagnosis and treatment of the PLC is still lacking, and much controversy remains.

Considering the literature review, there is not a reconstruction technique that clearly prevails over the others. As anatomic, biomechanical, and clinical knowledge of PLC injuries continues to progress, finding the balance between re-creating native anatomy and safely performing PLC reconstruction provides a big challenge. Treatment decisions should be made on a case-by-case basis.

Cite this article: EFORT Open Rev 2021;6:676-685. DOI: 10.1302/2058-5241.6.200096