Remnant-Tensioning Single-Bundle Anterior Cruciate Ligament Reconstruction Provides Comparable Stability to and Better Graft Vascularity Than Double-Bundle Anterior Cruciate Ligament Reconstruction in Acute or Subacute Injury: A Prospective Randomized Controlled Study Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging

The methods of quantifying knee laxity in the ACL injured population: A review

INTRODUCTION

Anterior Cruciate Ligament (ACL) injuries equate to a large proportion of Emergency Department attendances worldwide and continue to place significant burden on primary care services. Diagnosis of this injury relies on subjective physical examination tests such as the Lachman's and Pivot Shift test; results of which can vary depending on clinician experience and individual interpretation.

AIMS

This review seeks to identify current approaches past and present to objectively measuring knee laxity caused by ACL injury and appraise the methods of the current apparatus' available to do this within the clinical setting.

METHODS

A literature search across three databases (MEDLINE, EMBASE and CINAHL) was conducted, and an inclusion and exclusion criteria applied to the 780 retrieved texts to extract 19 papers fulfilling this objective. Articles published after the year 2000 were considered. The main technologies noted that quantified knee laxity were arthrometry devices, inertial motion units (IMUs), electromagnetic measurement systems (EMS), optical motion capture systems (OMC), and dynamic MRI.

CONCLUSION

Despite there being a multitude of technologies with capability to accurately measure aspects of knee laxity, there is no agreed objective measure for doing so in the clinical setting. This highlights a need for improved collaboration between the relevant stakeholders to achieve this aim.

Comparison of clinical, radiological, and second-look arthroscopic outcomes between hamstring autograft and tibialis allograft following remnant-tensioning anterior cruciate ligament reconstruction

BACKGROUND

The remnant-tensioning (RT) anterior cruciate ligament reconstruction (ACLR) has been reported to have excellent postoperative outcomes. However, the influence of graft selection on postoperative outcomes of autografts and allografts after RT-ACLR has been poorly investigated. The purpose of our study was to compare the clinical, radiological, and second-look arthroscopic outcomes of autografts and allografts following RT-ACLR.

METHODS

Between January 2013 and May 2020, 94 and 64 patients were enrolled in auto (hamstring tendon) and allo (tibialis tendon) groups, respectively. For subgroup analysis, patients were divided into two age categories: ≤34 and > 34 years of age. Stability tests, including the Lachman and Pivot shift tests, side-to-side differences on Telos stress radiographs and KT-2000 arthrometer, patient-reported outcome measurements (PROMs), and graft status on postoperative magnetic resonance imaging (MRI) and second-look arthroscopy, were evaluated and compared between the two groups.

RESULTS

The two groups showed no statistically significant differences in stability outcomes or PROMs for patients aged ≤ 34 and > 34 years. Furthermore, both groups demonstrated comparable postoperative graft status on postoperative MRI and second-look arthroscopy analyses in patients aged ≤ 34 and > 34 years.

CONCLUSION

RT-ACLR using allografts yielded similar postoperative clinical outcomes, MRI findings, and second-look results compared to autografts, irrespective of patients' age. Therefore, allografts may serve as a viable option for patients scheduled for RT-ACLR.

Double-Bundle Versus Single-Bundle Anterior Cruciate Ligament (ACL) Reconstruction: A Systematic Review and Meta-Analysis of Knee Stability Outcomes

This systematic review and meta-analysis compares the effectiveness of single-bundle (SB) and double-bundle (DB) ACL reconstruction techniques in improving knee stability and functional outcomes in patients with ACL injuries. A structured search across PubMed, Scopus, Google Scholar, and the Cochrane Library identified studies comparing SB and DB ACL reconstructions. Ten studies met the inclusion criteria, including randomized controlled trials, prospective, and retrospective studies. The primary outcomes analyzed were the International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Lachman test, and pivot-shift test results. Meta-analytic methods included calculating standardized mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs) alongside assessments of heterogeneity using the I² statistic. The meta-analysis showed no significant difference between SB and DB techniques for IKDC subjective scores (SMD: -0.14, 95% CI: -0.68 to 0.39, p = 0.59) or Lysholm scores (SMD: -0.18, 95% CI: -0.39 to 0.02, p = 0.08). Lachman test results also indicated no significant differences between techniques (pooled OR: 1.02, 95% CI: 0.70-1.47, p = 0.92). Pivot-shift test outcomes similarly revealed comparable rotational stability (OR: 1.00, 95% CI: 0.70-1.43, p = 1.00). Moderate heterogeneity was observed across analyses (I² = 37%-43%), reflecting variations in study designs and patient populations. SB and DB ACL reconstruction techniques achieve similar functional outcomes and knee stability, with no significant differences in Lachman test results, pivot-shift outcomes, or patient-reported measures. Further research with standardized methodologies is needed to verify these findings across diverse populations.

Combined over-the-top reconstruction with posterolateral bundle remnant re-tensioning in pediatric anterior cruciate ligament reconstruction: A technical note

Epiphyseal injury, particular on femoral side, is a major concern in pediatric anterior cruciate ligament (ACL) reconstruction. Therefore, the over-the-top route (OTTR) method has frequently been selected in pediatric ACL reconstruction, with good clinical results reported. However, a cadaver study reported the inferior rotational stability of the OTTR method to that of anatomical single bundle reconstruction. In recent years, a new method of reconstruction, which involves the remnant being detached, re-tensioned, and re-attached, achieved good short-term results. We developed a surgical method to restore the remnant to the posterolateral (PL) bundle footprint and obtain rotational stability in patients, thereby preserving the remnant. We hypothesized that repairing the residual remnant to the PL bundle footprint in pediatric ACL reconstruction could achieve rotational stability. This report offers the surgical techniques for PL bundle tensioning repair using remnants in the pediatric ACL OTTR procedure.

Comparison of Clinical and Radiographic Outcomes According to the Presence or Absence of a Posterior Draw Force during Graft Fixation in Anterior Cruciate Ligament Reconstruction

Background and Objectives: A reduction forced toward the posterior side during graft fixation may help to lessen anterior tibial translation after ACL reconstruction. The purpose was to compare the clinical and radiological outcomes of graft fixation when a posterior draw was used and when it was not used during anterior cruciate ligament (ACL) reconstruction surgery. Materials and Methods: Of 110 patients who had undergone primary arthroscopic ACL reconstruction between January 2017 and August 2020, in all, 76 patients had been operated on without a posterior draw (non-draw group), and 34 patients had received surgery with a posterior draw (draw group). The results of the Lachman test and the pivot-shift test, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) indexes, the Lysholm scores, the International Knee Documentation Committee (IKDC) subjective scores, and side-to-side difference (STSD) on stress radiography were compared between the two groups. Results: The postoperative WOMAC indexes, Lysholm scores, and IKDC subjective scores were similar across both groups. Postoperative STSD (2.4 ± 2.2 for the non-draw group vs. 2.0 ± 2.2 for the draw group; p = 0.319) and change in STSD (3.5 ± 3.5 for preoperative STSD vs. 4.3 ± 4.4 for postoperative STSD; p = 0.295) were not superior in the draw group. Conclusions: The take-home message is that graft fixation with a posterior draw during ACL reconstruction did not result in significantly better postoperative stability. The postoperative clinical outcomes were similar between both groups.

Effects of remnant preservation in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

Background

Compared with standard anterior cruciate ligament (ACL) reconstruction, it is controversial whether anterior cruciate ligament reconstruction (ACLR) with remnant preservation can lead to better clinical outcomes. We conducted a systematic study and meta-analysis to assess the differences in clinical efficacy between the two.

Method

We searched for clinical randomized controlled studies and cohort studies included in the Cochrane library, PubMed, and Embase from March 2012 to March 2022 in English. The included studies were ACLR with or without remant preservation, and the data were extracted and the quality of the included studies was assessed by two authors, respectively. Revman 5.4 was used for statistical analysis and conclusions were presented.

Result

Ten articles containing a total of 777 patients were finally included. There was no significant difference in postoperative Lachman test [OR = 1.66, 95%CI (0.79, 3.49), P = 0.18 > 0.05], Tegner score [SMD = −0.13, 95%CI (−0.47, 0.22), P = 0.46 > 0.05], synovial coverage rate by second-look arthroscopy [OR = 1.55, 95%CI (0.66, 3.65), P = 0.32 > 0.05], the rate of cyclops lesion [OR = 3.92, 95%CI (0.53, 29.29), P = 0.18 > 0.05], joint range of motion [SMD = 0.27, 95%CI (−0.13, 0.68), P = 0.19 > 0.05] and re-injury rate [OR = 0.57, 95%CI (0.18, 1.74), P = 0.32 > 0.05] between the two groups. There were statistically significant differences in postoperative Lysholm score [SMD = 0.98, 95% CI (0.32, 1.64), P = 0.004 < 0.05], International Knee Documantation Committee grade (IKDC grade) [OR = 2.19, 95%CI (1.03, 4.65), P = 0.04 < 0.05], Pivot shift test [OR = 1.71, 95%CI (1.06, 2.77), P = 0.03 < 0.05], KT1000/2000 arthrometer side-to-side difference [SMD = −0.22, 95%CI (−0.42, −0.03), P = 0.02 < 0.05], operation time [SMD = 11.69, 95%CI (8.85, 14.54), P = 0.00001 < 0.05] and degree of tibial tunnel enlargement [SMD = −0.66, 95%CI (−1.08, −0.23), P = 0.002 < 0.05].

Conclusion

This meta-analysis concluded that remnant preservation significantly had better results in terms of patient functional score (Lysholm, IKDC), knee stability (Pivot shift test, postoperative side-to-side anterior laxity) and tibial tunnel enlargement. In terms of complications (incidence of Cyclops lesions, range of motion, re-injury rate), no significant differences were seen between the two groups. Although many studies concluded that remnant preservation could bring better synovial coverage, this meta-analysis indicated that there is insufficient evidence to support it, possibly due to different remnant preservation procedures.The potential risks associated with longer operation times are also worth considering.

Analysis of Hemodynamic Changes After Medial Patellofemoral Ligament Reconstruction

The resumption of blood flow is an important factor in the remodeling process of the graft. The purpose of this study is to evaluate hemodynamic changes after medial patellofemoral ligament (MPFL) reconstruction using magnetic resonance angiography (MRA) as the evaluation of graft remodeling. Eleven knees that underwent anatomical MPFL reconstruction with the semitendinosus tendon were studied. We evaluated the blood flow around the bone tunnel wall in the arterial phase using MRA approximate 3 months and 1 year after surgery. Clinical and radiological evaluations were also analyzed. MRA showed an inflow vessel into the bone tunnel wall from the medial superior genicular artery on the femoral side, and from the articular branch of the descending genicular artery and the medial superior genicular artery on the patellar side. This contrast effect was decreased at 12 months after surgery in all cases. The clinical scores improved from baseline one year postoperatively. We revealed the blood flow to the bone tunnel wall after anatomical MPFL reconstruction is detected by MRA. The blood flow started within 2 or 3 months postoperatively and was sustained for 12 months. This study supported remodeling of the graft continues 3 months after surgery when the conformity of the patellofemoral joint stabilizes.

Remnant Tensioning Through Pullout Sutures From the Femoral Tunnel During Anatomic Anterior Cruciate Ligament Reconstruction

Even after anterior cruciate ligament (ACL) tear, its remnant retains the vascularized synovial sheets, fibroblasts, myofibroblasts, and various mechanoreceptors within it. The aim of preserving the remnant is to retain these components during ACL reconstruction. In the recent past, there has been an increasing trend towards preserving remnants during ACL reconstruction. Although preserving remnants have physiological advantages, cyclops lesion and extension loss were among the most feared complications. Cyclops and loss of extension are due to the fallback of the remnant into the notch. Moreover, the mechanoreceptors present in the remnant are not active when the remnant is lax. These mechanoreceptors are active when the remnant is in tension. Thus, rather than merely preserving the remnant, it is essential to tension it for more physiological functions. Although there are various techniques of remnant tensioning described in the literature, these techniques require tampering of the fixation devices or an extra fixation device adding to the cost of surgery. We describe our modification of the remnant-tensioning method during anatomic ACL reconstruction. In this technique, the sutures holding the remnant are pulled out through the anatomic femoral tunnel and fixed with an interference screw along with the hamstring graft. This technique is cost-effective, reproducible, and does not require tampering with the fixation devices. Moreover, the direction of remnant pull will be the same as that of the reconstructed graft making both the graft and remnant anatomical in orientation. Suture management and visibility of the intraarticular structures during this procedure are a few downsides of this technique. The only prerequisite of this technique is a good quality remnant to hold the sutures.

Remnant Tissue Preserved Transtibial Anterior Cruciate Ligament Reconstruction With Femoral Tunnel Created Behind the Resident's Ridge

Although the transtibial (TT) technique for single-bundle (SB) arthroscopic anterior cruciate ligament (ACL) reconstruction has been widely used, surgeons often disadvantageously create the femoral bone tunnel at the arthroscopically noon position, which is alleged the "ACL isometric point," when the femoral bone tunnel could be created behind the resident's ridge with TT-SB ACL reconstruction by paying attention to the location of the tibial tunnel inlet and the angle of tibial tunnel. This alternative approach preserves ACL remnant tissue, which might contribute to better postoperative remodeling and regeneration of proprioceptive mechanoreceptors. This technique reduces surgical invasiveness and can enhance postoperative graft remodeling and proprioceptive recovery. To successfully use the devices required for this procedure, surgeons must understand the proper techniques. Hence, this technical note aims to demonstrate TT-SB ACL reconstruction with remnant tissue preservation.

Medical Journals Should Be a Forum for Disruptive Research

Disruptive innovation completely changes the traditional way that we operate and may only be realized in retrospect. For example, shoulder superior capsule reconstruction (SCR) is a complete change from the traditional methods of treating massive, irreparable rotator cuff tears and pseudoparalysis. Classic examples of disruptions in orthopaedic surgery include distraction osteogenesis, total hip joint replacement arthroplasty, and modern orthopaedic trauma care. Orthopaedic technologies that promise future disruption include artificial intelligence, surgical simulation, and orthopaedic biologics, including mesenchymal stromal cell (MSC) and gene therapy. Most of all, arthroscopic surgery completely changed the way we operate by using new methods and technology. Many never saw it coming. The challenge going forward is to motivate and foster new ideas and research that result in innovation and progress. Skepticism has a place, but not at the expense of transformative ideas, particularly as medical journals offer the alternative of prospective hypothesis testing using the scientific method, followed by unbiased peer review, and publication. Medical journals should be a forum for disruptive research.

Sandwich-Style Anterior Cruciate Ligament Reconstruction: Double-Bundle Anterior Cruciate Ligament Reconstruction With In-Between Remnant Preservation

Various degree of remnant tissues exists following anterior cruciate ligament (ACL) injury. Making use of these tissues may be helpful for the reconstructed ACL from many aspects. There are many methods of remnant preservation and use, as well as many types of combined ACL reconstruction. However, the most effective methods of remnant reuse as well as ACL reconstruction are still being pursued. We introduce an anatomical double-bundle transtibial ACL reconstruction with in-between remnant preservation technique named sandwich-style ACL reconstruction. The indication of this technique is complete ACL tear with a large volume of connectable remnant. The main tricks of this technique are proper ligation of the remnant, proper location of the anteromedial-bundle tibial tunnels, and passing the anteromedial bundle through the shallow side of the remnant. We believe the introduction of this technique will provide more options for remnant preservation and ACL reconstruction.