Prospective randomized clinical evaluation of conventional single-bundle, anatomic single-bundle, and anatomic double-bundle anterior cruciate ligament reconstruction: 281 cases with 3- to 5-year follow-up

Proximally positioned femoral grafts decrease passive anterior tibial subluxation in anterior cruciate ligament reconstruction using a posterior trans-septal portal

PURPOSE

To compare the anterior and posterior trans-septal (TS) portal approaches in anterior cruciate ligament reconstruction (ACLR) by evaluating femoral tunnel positioning and passive anterior tibial subluxation (PATS).

METHODS

A total of 205 patients who underwent primary ACLR using the outside-in technique between March 2018 and December 2021 were retrospectively enrolled. Patients were classified into two groups based on the viewing techniques: the anterior group was treated using anteromedial or anterolateral portals (n = 155), and the TS group was treated using posterior TS portal (n = 55). The relative locations of the femoral tunnel were evaluated using the deep-shallow planes (X-axis) and superior-inferior planes (Y-axis) with the quadrant method in the lateral femoral condyle on a 3-dimensional computed tomography image. Anterior tibial subluxation for the lateral and medial compartments relative to the femoral condyles was evaluated as measured on magnetic resonance imaging. Knee laxity was assessed using the pivot-shift test and stress radiography.

RESULTS

In the posterior TS group, the femoral tunnel was usually located deeper on the X-axis and more superior on the Y-axis, which corresponds to a more proximal position, than in the anterior group (deeper on the X-axis and superior on the Y-axis). Moreover, the femoral tunnel locations in this group were more compactly distributed than those in the anterior group. The TS group showed significantly better reduction of postoperative PATS in the lateral compartments than the anterior group (anterior group vs. TS group: lateral compartment, 3.2 ± 3.1 vs. 4.5 ± 3.2 mm; p = .016). Significantly better results were found in the TS group for knee stability as assessed by the pivot-shift grade (p = .044); however, there were no significant differences between the two groups with respect to patient-reported outcome measures (p > .05) and other complications (p = .090).

CONCLUSION

Our results suggest that positioning the femoral tunnel using the posterior TS portal approach may lead to better outcomes in terms of PATS and rotational stability compared to the anterior portal approach in ACLR.

Transtibial versus anteromedial transportal femoral tunnel in single-bundle anterior cruciate ligament reconstruction: a systematic review and meta-analysis of prospective randomized controlled trials

The purpose of this study was to systematically review and meta-analyze randomized controlled trials (RCTs) reporting the comparative clinical and functional outcomes, postoperative complications, and radiological outcomes of single-bundle anterior cruciate ligament reconstruction (ACLR) performed using the transtibial (TT) approach or anteromedial (AM) technique. A systematic review of the literature was performed according to Cochrane and PRISMA guidelines. RCTs comparing TT and AM techniques were considered only. The quality of the studies was defined using the GRADE system, and the risk of bias was assessed with the RoB 2 tool. The primary endpoint was to systematically review and meta-analyze the clinical outcomes, residual laxity and failure rate of both AM and TT techniques. In the current meta-analysis 13 RCTs involving 989 patients who underwent arthroscopic single-bundle ACLR (486 TT and 503 AM) were included. Patients undergoing AM technique resulted in higher objective-IKDC (p < 0.001) and Lysholm scores (p = 0.002), despite a lower incidence of pathological anterior tibial translation (p < 0.001) and positive pivot-shift test (p < 0.001). No differences were detected in IKDC subjective score (p = 0.26), Tegner activity scale (p = 0.18) and graft failure (p = 0.07). ACL reconstruction through AM portal technique provides better clinical outcomes and lower incidence of residual rotational and anteroposterior laxity in comparison with the TT technique. No statistically significant difference in subjective outcomes and graft failure was reported.

Correlation between higher lateral tibial slope and inferior long term subjective outcomes following single bundle anterior cruciate ligament reconstruction

BACKGROUND

The impact of anatomical factors, such as the lateral tibial slope (LTS), on outcomes following anterior cruciate ligament (ACL) reconstruction is an area of growing interest. This study was led by the observation that patients with a higher LTS may have different recovery trajectories.

HYPOTHESIS/PURPOSE

The purpose of this study was to investigate the correlation between a higher LTS and long term subjective outcomes following single-bundle ACL reconstruction.

STUDY DESIGN

This study was designed as a retrospective cohort study.

METHODS

The study comprised 138 patients who underwent single-bundle ACL reconstruction. The LTS was measured on preoperative radiographs. Patient-reported outcome measures (PROMs) were collected, which included the Lysholm Knee Score, UCLA Activity Score, IKDC Score, and Tegner Activity Score, over a mean follow-up duration of 137 months.

RESULTS

A significant negative correlation was found between LTS and all measured PROMs (p < 0.001). The established cut-off value of LTS distinguishing between "Good" and "Fair" Lysholm scores was 8.35 degrees. Female patients have statistically significant higher LTS and lower PROMs scores than male. Patients with LTS greater than or equal to 8.35 had significantly lower PROMs, indicative of poorer functional and subjective outcomes.

CONCLUSION

Our findings suggest that a higher LTS is associated with inferior subjective outcomes following single-bundle ACL reconstruction in long term. The LTS cut-off value of 8.35 degrees could potentially be used as a reference in preoperative planning and patient counseling.

CLINICAL RELEVANCE

Understanding the relationship between LTS and ACL reconstruction outcomes could inform surgical planning and postoperative management. These findings highlight the need to consider anatomical variances, such as LTS, when assessing patient-specific risks and recovery expectations, contributing to the advancement of personalized care in sports medicine.

Robot-assisted anterior cruciate ligament reconstruction based on three-dimensional images

Background Tunnel placement is a key step in anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the accuracy of bone tunnel drilling in arthroscopic ACL reconstruction assisted by a three-dimensional (3D) image-based robot system. Methods Robot-assisted ACL reconstruction was performed on twelve freshly frozen knee specimens. During the operation, three-dimensional images were used for ACL bone tunnel planning, and the robotic arm was used for navigation and drilling. Twelve patients who underwent traditional arthroscopic ACL reconstruction were included. 3D computed tomography was used to measure the actual position of the ACL bone tunnel and to evaluate the accuracy of the robotic and traditional ACL bone tunnel. Results On the femoral side, the positions of robotic and traditional surgery tunnels were 29.3 ± 1.4% and 32.1 ± 3.9% in the deep-to-shallow direction of the lateral femoral condyle (p = 0.032), and 34.6 ± 1.2% and 21.2 ± 9.4% in the high-to-low direction (p < 0.001), respectively. On the tibial side, the positions of the robotic and traditional surgical tunnels were located at 48.4 ± 0.9% and 45.8 ± 2.8% of the medial-to-lateral diameter of the tibial plateau (p = 0.008), 38.1 ± 0.8% and 34.6 ± 6.0% of the anterior-to-posterior diameter (p = 0.071), respectively. Conclusions In this study, ACL reconstruction was completed with the assistance of a robot arm and 3D images, and the robot was able to drill the bone tunnel more accurately than the traditional arthroscopic ACL reconstruction.

Double-bundle anterior cruciate ligament reconstruction resulted in better International Knee Documentation Committee objective grading at fifteen year follow-up compared to single-bundle reconstruction

PURPOSE

The aim of this prospective randomized study was to evaluate whether the use of the anatomic double-bundle (DB) method for anterior cruciate ligament (ACL) reconstruction results in better clinical outcomes and a lower incidence of graft failure compared with the anatomic single-bundle (SB) method. The hypothesis was that DB ACL reconstruction would result in a lower incidence of graft failure.

METHODS

Patients were randomly assigned to either the SB group (n = 78) or the DB group (n = 75). Evaluation included clinical testing, subjective assessments, functional testing, and International Knee Documentation Committee (IKDC) objective grading. Surgical techniques were anatomic, and the rehabilitation protocol was standardized.

RESULTS

At 15-year follow-up, information was available on 100 patients (65%), of whom 55 (36%) were accepted in the final statistical analysis. There were almost three times as many graft failures in the SB group, but the result wasn´t statistically significant. Subjective assessments, knee stability (KT -1000 and pivot shift), range of motion (ROM), and functional one leg hop test showed no statistically significant differences between the groups. However, DB ACL reconstruction resulted in better International Knee Documentation Committee objective grading (P < 0.001).

CONCLUSION

At the 15-year follow-up, double-bundle surgery resulted in significantly better International Knee Documentation Committee objective grading compared to single-bundle surgery.

Comparison of Graft Type and Fixation Method in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis Based on Randomized Control Studies

BACKGROUND

The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee. ACL reconstruction (ACLR) proves the standard for treating this injury. However, graft choice and method of fixation remain a heavily debated topic. This study investigates the following: bone-patellar tendon-bone (BPTB) vs. hamstring tendon (HT) autograft, single-bundle vs. double-bundle hamstring graft, and metal vs. bioabsorbable screws in ACLR.

METHODS

A systematic review was performed on PubMed and Google Scholar according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data were collected on patient demographics, complications, and functionality scores including International Knee Documentation Committee (IKDC) and Lysholm scores. A systematic review and meta-analysis were conducted with Review Manager. Outcome measurements were determined using forest plots with significant differences considered p < 0.05.

RESULTS

Twenty-five studies were included, accounting for 2,170 patients. No statistically significant difference was appreciated when comparing BPTB to hamstring autografts. Patients who received a double bundle HT autograft exhibited significantly superior outcomes in terms of revision (p = 0.05), failure (p = 0.002), normal pivot shift tests (p = 0.04), and normal IKDC (p = 0.008). When comparing screw types, bioabsorbable screws had a greater Lysholm score (p = 0.01) and lower failure rates for copolymer screws (p = 0.03).

CONCLUSION

Overall, the data collected suggested that BPTB and HT autografts display similar postoperative results. However, if an HT autograft is used, the data suggest a double-bundle graft improves both functionality and decreases the possible complications. Finally, bioabsorbable screws prove superior to metal screws when looking at both functionality and failure rates. Further research into the superior graft type is still needed.

LEVEL OF EVIDENCE

Level II. See Instructions for Authors for a complete description of levels of evidence.

Morphometric Analysis of the Tibial Attachment Shape of the Anterior Cruciate Ligament and Its Relationship With the Location of the Anterior Horn of the Lateral Meniscus

BACKGROUND

The success of anterior cruciate ligament (ACL) reconstruction relies on the accurate replication of the native ACL anatomy, including attachment shapes. The tibial attachment of the ACL exhibits significant shape variations with elliptical, C, and triangular shapes, highlighting the need for objective classification methods and additional information to identify individual anatomic variations.

HYPOTHESIS

The location of the attachment of the anterior horn of the lateral meniscus (AHLM) may determine the shape of the ACL attachment.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

The study used 25 knees from 17 Japanese cadavers for macroscopic anatomic examination and quantitative analysis. The shape of the ACL attachment was quantified using principal component analysis with elliptical Fourier descriptors, whereas the AHLM location was quantified by measuring its mediolateral and anteroposterior positions on the superior surface of the tibia. Reliability was assessed statistically.

RESULTS

The shape of the tibial attachment of the ACL varied among individuals and was classified as elliptical, C-shaped, or triangular. Scatterplots of the principal components of the ACL attachment shape showed overlapping regions of elliptical, C-shaped, and triangular ACL attachments, indicating that a C-shaped attachment is intermediate between elliptical and triangular attachments. The location of the AHLM attachment also varied, with areas in the anterolateral, anteromedial, or posteromedial region. The ACL shape and AHLM location were related, with elliptical, C-shaped, and triangular ACL attachments corresponding to anterolateral, anteromedial, and posteromedial AHLM attachments, respectively.

CONCLUSION

The AHLM attachment location influences the shape of the ACL attachment. Information on the location of the AHLM attachment can aid in predicting the shape of the ACL attachment during ACL reconstruction, potentially improving footprint coverage.

Anatomic Double-Bundle and Single-Bundle Reconstructions Yield Similar Outcomes Following Anterior Cruciate Ligament Rupture: A Systematic Review and Meta-analysis

PURPOSE

To evaluate outcomes of arthroscopic single-bundle (SB) versus anatomic double-bundle (ADB) anterior cruciate ligament reconstruction (ACLR) in adults through a synthesis of randomized controlled trials (RCTs). We hypothesized that SB and ADB methods would lead to similar outcomes after reconstruction of ACL rupture.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist guided our reporting. To identify RCTs that compared SB and ADB reconstructions, a thorough literature search was conducted of PubMed, Embase, Cochrane library, and Web of Science. The methodologic quality of each included study was independently assessed by 2 authors using the Cochrane Collaboration's risk of bias tool. The Anatomic ACL Reconstruction Scoring Checklist (AARSC) was used to screen the eligibility of each study's operative approaches. Twelve clinical outcomes were investigated through pooled analyses conducted using Review Manager 5.3.

RESULTS

This meta-analysis synthesized 13 RCTs comparing postoperative outcomes between ADB and SB reconstructions of ACLs. After a minimum follow-up of 12 months, ADB and SB technique resulted in similar subjective clinical outcomes, including the International Knee Documentation Committee subjective score, Lysholm score, Tegner activity score, and Knee injury and Osteoarthritis Outcome Score sports subscale. Similarly, no statistically significant outcomes were found for objective outcomes such as International Knee Documentation Committee objective grade, pivot-shift test, Lachman test, side-to-side difference, extension deficit, flexion deficit, and osteoarthritis change. However, patients who underwent SB reconstruction had significantly greater complication rates than those that underwent ADB reconstruction.

CONCLUSIONS

When an ACLR approach meets a minimal total AARSC score of 8, ADB and SB techniques may result in similar subjective and objective outcomes, but the ADB technique may lead to lower complication rates following surgery. We recommend that surgeons favor ADB ACLR, as guided by the AARSC.

LEVEL OF EVIDENCE

Level I, systematic review and meta-analysis of Level I randomized controlled trials.

Race and Gender Differences in Anterior Cruciate Ligament Femoral Footprint Location and Orientation: A 3D-MRI Study

OBJECTIVE

The femoral tunnel position is crucial to anatomic single-bundle anterior cruciate ligament (ACL) reconstruction, but the ideal femoral footprint position are mostly based on small-sized cadaveric studies and elderly patients with a single ethnic background. This study aimed to identify potential race- or gender-specific differences in the ACL femoral footprint location and ACL orientation, determine the correlation between the ACL orientation and the femoral footprint location.

METHODS

Magnetic resonance images (MRIs) of 90 Caucasian participants and 90 matched Chinese subjects were used for reconstruction of three-dimensional (3D) femur and tibial models. ACL footprints were sketched by several experienced orthopedic surgeons on the MRI photographs. The anatomical coordinate system was applied to reflect the ACL footprint location and orientation of scanned samples. The femoral ACL footprint locations were represented by their distance from the origin in the anteroposterior (A/P) and distal-proximal (D/P) directions. The orientation of the ACL was described with the sagittal, coronal and transverse deviation angles. The ACL orientation and femoral footprint position were compared by the two-sided t-test. Multiple regression analysis was used to study the correlation between the orientation and femoral footprint position.

RESULTS

The average femur footprint A/P position was -6.6 ± 1.6 mm in the Chinese group and -5.1 ± 2.3 mm in the Caucasian group, (p < 0.001). The average femur footprint D/P position was -2.8 ± 2.4 mm in Chinese and - 3.9 ± 2.0 mm in Caucasians, (p = 0.001). The Chinese group had a mean difference of a 1.5 mm (6.1%) more posterior and 1.1 mm (5.3%) more proximal in the position from the flexion-extension axis (FEA). And the males have a sagittal plane elevation about 4-5° higher than females in both racial groups. Furthermore, for every 1% (0.40 mm) increase in A/P and D/P values, the sagittal angle decreased by about 0.12° and 0.24°, respectively; the coronal angle decreased by about 0.10° and 0.30°, respectively. For every 1% (0.40 mm) increase in D/P value, the transverse angle increased by about 0.14°.

CONCLUSION

The significant race- and gender-specific differences in the femoral footprint and orientation of the ACL should be taken in consideration during anatomic single-bundle ACL reconstruction. Furthermore, the quantitative relationship between the ACL orientation and the footprint location might provide some reference for surgeons to develop a surgical strategy in ACL single-bundle reconstruction and revision.

Shear wave elastography demonstrates different material properties between the medial collateral ligament and anterolateral ligament

BACKGROUND

Anterolateral ligament and medial collateral ligament injuries could happen concomitantly with anterior cruciate ligament ruptures. The anterolateral ligament is injured more often than the medial collateral ligament during concomitant anterior cruciate ligament ruptures although it offers less restraint to knee movement. Comparing the material properties of the medial collateral ligament and anterolateral ligament helps improve our understanding of their structure-function relationship and injury risk before the onset of injury.

METHODS

Eight cadaveric lower extremity specimens were prepared and mechanically tested to failure in a laboratory setting using a hydraulic platform. Measurements of surface strains of superficial surface of each medial collateral ligament and anterolateral ligament specimen were found using three-dimensional digital image correlation. Ligament stiffness was found using ultrasound shear-wave elastography. t-tests were used to assess for significant differences in strain, stress, Young's modulus, and stiffness in the two ligaments.

FINDINGS

The medial collateral ligament exhibited greater ultimate failure strain along its longitudinal axis (p = 0.03) and Young's modulus (p < 0.0018) than the anterolateral ligament. Conversely, the anterolateral ligament exhibited greater ultimate failure stress than the medial collateral ligament (p < 0.0001). Medial collateral ligament failure occurred mostly in the proximal aspect of the ligament, while most anterolateral ligament failure occurred in the distal or midsubstance aspect (P = 0.04).

INTERPRETATION

Despite both being ligamentous structures, the medial collateral ligament and anterolateral ligament exhibited separate material properties during ultimate failure testing. The weaker material properties of the anterolateral ligament likely contribute to higher rates of concomitant injury with anterior cruciate ligament ruptures.

Anteromedial Portal versus Transtibial Drilling Techniques for Femoral Tunnel Placement in Arthroscopic Anterior Cruciate Ligament Reconstruction: Radiographic Evaluation and Functional Outcomes at 2 Years Follow-Up

The aim of this study was to compare the functional and radiographic outcomes of arthroscopic single-bundle anterior cruciate ligament reconstruction (ACLR) using either the anteromedial (AM) portal technique or transtibial (TT) technique. We identified 404 patients who underwent arthroscopic ACLR by a single surgeon between January 2006 and December 2016 at our institution. The TT portal was utilized in femoral tunnel drilling in 202 patients (TT group) while the AM portal was used in 202 patients (AM group). The mean postoperative follow-up duration was 26 months (range: 24-33 months). Postoperative radiographic femoral and tibial tunnel positions were assessed by two independent observers. Functional outcomes were evaluated with Tegner, Lysholm, and Knee Injury and Osteoarthritis Outcome score (KOOS) scores. On the anteroposterior plain radiographs, the mean femoral tunnel position relative to the lateral femoral condyle was 46.8% for the AM group versus 48.6% in the TT group, respectively (p=0.003). The mean graft inclination angle was 31.9° and 22° in the AM and TT groups, respectively (p<0.0001). On the lateral radiographs, the mean femoral tunnel placement across Blumensaat's line in relation to the anterior femoral cortex was 84% in the AM group while it was 78% in the TT group (p<0.0001). At 2 years postoperatively, there were no significant differences in the mean Tegner, Lysholm, and KOOS scores between the two patient groups. The graft failure rate at 2 years follow-up was 4.5% (n=9) in the AM group while it was 2.5% (n=5) in the TT group (p=0.2). Femoral tunnel placement was more anatomical with the AM portal technique compared with the TT technique. However, there was no significant difference in postoperative functional outcomes between the two patient groups. The AM portal technique appears to have a higher graft failure rate. This might be attributed to increased graft loading in an anatomical position.

Accuracy of Femoral Tunnel Localization With Mixed Reality Technology-Assisted Single-Bundle ACL Reconstruction

Background

It is clinically challenging to accurately drill femoral and tibial tunnels to reconstruct the anterior cruciate ligament (ACL). Mixed reality (MR) technology, a further development of virtual reality technology, presents virtual scene information in real time and establishes an interactive feedback information loop among the real world, the virtual world, and the user.

Purpose/Hypothesis

The purpose of this study was to investigate the structural and early clinical outcomes of ACL reconstruction assisted by MR technology. It was hypothesized that MR technology would improve the accuracy of tunnel localization.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 44 patients at a single institution who underwent arthroscopic single-bundle ACL reconstruction between June 2020 and March 2022. Reconstruction with the aid of MR technology was performed in 21 patients (MR group), and conventional arthroscopic reconstruction was performed in 23 patients. Postoperatively, the parameters related to the bone tunnel positioning were compared by computed tomography imaging with 3-dimensional (3D) reconstruction, and 12-month postoperative clinical outcomes were assessed with the Lysholm and International Knee Documentation Committee scores.

Results

There was no statistically significant difference in projection angles in the coronal, axial, or sagittal plane between the preoperative virtually created tunnel guide pin and the actual tunnel (P > .05 for all). In the MR group, the center of the femoral tunnel exit was closer to the apex of the lateral femoral condyle along the proximal-distal axis (14.07 ± 4.12 vs 17.49 ± 6.24 mm for the conventional group; P < .05) and the graft bending angle was lower (117.71° ± 8.08° vs 127.81° ± 11.91° for the conventional group; P < .05). The scatterplot of the femoral tunnel location distribution showed that the entrance and exit points in the MR group were more concentrated and closer to the ideal location of the preoperative design than in the conventional group. Patients in both groups had significant preoperative-to-postoperative improvement based on outcome scores (P < .001 for all), with no significant difference between groups.

Conclusion

ACL reconstruction with the aid of MR technology allowed for more accurate positioning and orientation of the femoral tunnel during surgery when compared with conventional reconstruction.

Untreated Injuries to the Anterolateral Capsular Structures Do Not Affect Outcomes and Kinematics after Anatomic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Injuries to the anterolateral complex (ALC) may contribute to increased rotatory knee laxity. However, it has not been evaluated whether such injuries affect in vivo kinematics when treated in situ. The purpose of this study was to determine the grade of ALC injury and its effect on kinematic and clinical outcomes of ACL-injured patients 24 months after anatomic ACL reconstruction. It was hypothesized that injury to the ALC would be significantly related to patient-reported outcomes (PROs) and in vivo knee kinematics during downhill running.

METHODS

Thirty-five subjects (mean age: 22.8 ± 8.5 years) participating in a randomized clinical trial to compare single- and double-bundle ACL reconstruction were included in the study. Subjects were divided into two groups based on the presence or absence of injury to the ALC, as determined on MRI scans performed within 6 weeks of injury. None of the patients underwent treatment for these ALC injuries. At 24 months, PROs, including the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Knee injury and Osteoarthritis Outcome Score (KOOS) and in vivo knee kinematics during downhill running, were obtained. Pivot-shift test results, PROs and in vivo knee kinematics were compared between groups with and without ALC injury using the Pearson's Chi Squared test and Mann-Whitney U test with significance set at p < 0.05.

RESULTS

The average interval between injury and performing the MRI scans was 9.5 ± 10 days. ALC injury was observed in 17 (49%) study participants. No significant differences were detected in PROs and in vivo kinematics between subjects with and without ALC injury (n.s.).

CONCLUSION

The findings of this study demonstrate that MRI evidence of an ALC injury does not significantly affect in vivo knee kinematics and PROs even in individuals with a high-grade ALC injury. Injuries to the ALC as observed on MRI might not be a useful indication for an anterolateral procedure.

Review of Cha et al. (2005) on "Arthroscopic Double Bundle Anterior Cruciate Ligament Reconstruction: An Anatomical Approach"

This classic discusses the original publication 'Arthroscopic double-bundle anterior cruciate ligament reconstruction (ACL): An anatomical approach', the first detailed description of the surgical technique popularised by Dr Freddie Fu. The technique, in which the anteromedial and posterolateral bundles of the ACL are reconstructed individually using two grafts with independent bone tunnels, was designed to more closely recreate the function of the native ACL by more closely reproducing the functional anatomy. This reconstruction was biomechanically superior to single-bundle reconstruction, particularly with regards to rotational control, leading to great interest from ACL surgeons around the world. Clinical superiority was more difficult to demonstrate; however, and the technical difficulty of the procedure has limited its use. Nevertheless, the pursuit of improved patient outcomes through attention to functional anatomical detail continues. 'Recreating the functional anatomy of the intact ACL remains the cornerstone of ACL reconstruction'.

Biomechanical Comparison of Anterior Cruciate Ligament Reconstruction Using a Single-Bundle Round or Ribbon-like Hamstring Tendon Graft

BACKGROUND

Persistent instability of the knee is reported in up to 30% of patients after anterior cruciate ligament (ACL) reconstruction. Based on anatomic findings showing that ACL is a flat ribbon-like structure that twists during knee flexion, a new surgical ACL reconstruction technique using a ribbon-like graft has been developed. However the effect of this surgical technique on knee kinematics has not yet been evaluated.

PURPOSE

To compare the anteroposterior and rotational stability of the knee after ACL reconstruction using single-bundle (SB) round and ribbon-like grafts in anterolateral-intact/deficient knees.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve human fresh-frozen cadaveric knees were tested with a 6 degrees of freedom robotic system. Internal rotation and anterior translation of the knee were recorded from 0° to 90° of flexion. A full kinematic assessment was performed in each of the following conditions: (1) intact knee, (2) after sectioning of the ACL, (3) after ACL reconstruction using a SB hamstring tendon graft in a round configuration and a ribbon-like configuration, and (4) after sectioning of the anterolateral structures. One-way analysis of variance and post hoc Tukey tests were used for statistical analyses.

RESULTS

When compared with the intact knee, the ACL-deficient knee demonstrated a mean ± SD increase in anterior translation and internal rotation of 6.3 ± 2.5 mm (P < .01) and 5.8°± 2.3° (P < .01), respectively. After ACL reconstruction using a SB ribbon-like graft, the mean difference in anterior translation and internal rotation as compared with the intact knee was -0.1 ± 1.5 mm (P = .842) and 0.0°± 1.1° (P = .999). These differences from the intact knee were also not significant after ACL reconstruction using a round graft (-0.1 ± 1.3 mm, P = .999; -0.5°± 1.5°, P = .401). In the ACL-reconstructed knee using either a ribbon-like or round graft, sectioning of the anterolateral structures did not induce a significant increase of anterior translation and internal rotation of the knee.

CONCLUSION

ACL reconstruction using a SB ribbon-like or round graft restored the kinematics of the intact knee at time zero. Secondary sectioning of the anterolateral structures in the ACL-reconstructed knee using both types of graft did not significantly affect the anterior translation and internal rotation of the knee.

CLINICAL RELEVANCE

This is the first biomechanical study on the new ACL reconstruction technique using a ribbon-like graft.

Femoral Tunnel Position Affects Postoperative Femoral Tunnel Widening after Anterior Cruciate Ligament Reconstruction with Tibialis Anterior Allograft

This study aims to identify potential factors for both femoral and tibial tunnel widening (TW) and to investigate the effect of TW on postoperative outcomes after anterior cruciate ligament (ACL) reconstruction with a tibialis anterior allograft. A total 75 patients (75 knees) who underwent ACL reconstruction with tibialis anterior allografts were investigated between February 2015 and October 2017. TW was calculated as the difference in tunnel widths between the immediate and 2-year postoperative measurements. The risk factors for TW, including demographic data, concomitant meniscal injury, hip-knee-ankle angle, tibial slope, femoral and tibial tunnel position (quadrant method), and length of both tunnels, were investigated. The patients were divided twice into two groups depending on whether the femoral or tibial TW was over or less than 3 mm. Pre- and 2-year follow-up outcomes, including the Lysholm score, International Knee Documentation Committee (IKDC) subjective score, and side-to-side difference (STSD) of anterior translation on stress radiographs, were compared between TW ≥ 3 mm and TW < 3 mm. The femoral tunnel position depth (shallow femoral tunnel position) was significantly correlated with femoral TW (adjusted R² = 0.134). The femoral TW ≥ 3 mm group showed greater STSD of anterior translation than the femoral TW < 3 mm group. The shallow position of the femoral tunnel was correlated with the femoral TW after ACL reconstruction using a tibialis anterior allograft. A femoral TW ≥ 3 mm showed inferior postoperative knee anterior stability.

Risk factors of residual pivot-shift after anatomic double-bundle anterior cruciate ligament reconstruction

INTRODUCTION

Although anterior cruciate ligament reconstruction (ACLR) is considered a successful procedure, residual pivot-shift after surgery remains to be solved. The purpose of this study was to comprehensively evaluate the risk factors of residual pivot-shift after anatomic double-bundle (DB) ACLR.

MATERIALS AND METHODS

A total of 164 patients who underwent primary anatomic DB-ACLR between January 2014 and December 2019 and screw removal after the index ACLR in our hospital were included in this retrospective case-control study. The manual pivot-shift test was performed under general anesthesia during screw removal surgery, and patients with grade 1 or higher pivot-shift were classified as the positive pivot-shift group, and those with grade 0 were defined as the negative pivot-shift group. Univariate and logistic regression analyses were performed to identify the factors associated with postoperative residual pivot-shift. Assessment included sex, age, time to surgery, preoperative Tegner activity scale, preoperative pivot-shift grade, preoperative anterior tibial translation by the KT-2000 arthrometer measurement, meniscus injury and its surgical procedure, knee hyperextension, cartilage damage, Segond fracture, medial and lateral posterior tibial slope, lateral-medial slope asymmetry, participation in pivoting sport/activity at the time of injury, and return to sports at postoperative one year line.

RESULTS

Postoperative positive pivot-shift was observed in 14 (8.5%) of 164 patients. The KT-2000 measurement at 1-year postoperatively was significantly higher in the residual pivot-shift-positive group than in the negative group (P < 0.05). Logistic regression analysis revealed that age of patients < 20 years [P < 0.05, odds ratio (OR): 6.1)], preoperative pivot-shift grade (P < 0.05, OR: 4.4), and hyperextended knee (P < 0.05, OR: 11.8) were risk factors of postoperative pivot-shift. There were no statistically significant differences between other variables.

CONCLUSIONS

Patients < 20 years of age, with high-grade preoperative pivot-shift, or hyperextended knees had a higher risk of residual postoperative pivot-shift.

Anatomical double-bundle anterior cruciate ligament reconstruction moderately improved tegner scores over the long-term: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

To assess the effects of anatomical double-bundle (DB) versus single-bundle (SB) for anterior cruciate ligament (ACL) reconstruction in skeletally mature patients with ACL injuries.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched from inception to February 7, 2022 were screened for randomized controlled trials. The Anatomic Anterior Cruciate Ligament Reconstruction Checklist was used to categorize studies as anatomic. A random-effects meta-analysis was conducted, with pooled results being summarized using mean difference (MD). Risk of Bias (RoB) was assessed using the RoB 2.0 tool. Certainty of evidence was rated using GRADE.

RESULTS

A search of 1371 unique articles yielded eight eligible trials, representing 735 patients (360 DB, 375 SB) with mean (SD) age of 28.5 (2.86) years and follow-up of 52.1 (36.2) months. Most trials had moderate to low RoB. Overall, DB was not significantly better than SB on Lysholm scores (MD = 0.52, 95% CI, - 1.80-2.85, p = 0.66; moderate certainty) or subjective International Knee Documentation Committee (IKDC) scores (MD = - 0.40, 95% CI, - 4.35-3.55, p = 0.84; moderate certainty). Tegner scores were significantly higher in SB than DB in the intermediate term (MD = - 0.72, 95% CI, - 1.10 to - 0.34, p = 0.0002; high certainty), while significantly higher in DB relative to SB in the long-term (MD = 0.52, 95% CI, 0.02-1.03, p = 0.04; high certainty).

CONCLUSION

DB ACL reconstruction significantly improves Tegner scores relative to SB ACL reconstruction over the long-term (t ≥ 5 years). Intermediate term Tegner scores favour SB reconstruction. In both durations, there was no clinically significant difference based on the pre-specified minimal clinically important difference of 1.0 point. There were also no significant differences in IKDC or Lysholm scores. Surgeons should consider anatomical DB ACL reconstruction as a result of long-term improvement in patient-reported outcomes.

LEVEL OF EVIDENCE

I.

Anatomic anterior cruciate ligament reconstruction: Freddie Fu's paradigm

Anterior cruciate ligament (ACL) reconstruction techniques have evolved over the past four decades. There is evidence that non-anatomic reconstruction techniques, such as traditional transtibial drilling, fail to recreate the native anatomy of the ACL, which can lead to increased rotatory knee instability, revision risk, and post-traumatic osteoarthritis. Anatomic ACL reconstruction has emerged as the gold standard, with the goal of restoring the patient's native anatomy and knee kinematics. This review will summarise the relevant anatomy, modern anatomic ACL reconstruction techniques, and literature supporting anatomic ACL reconstruction as the new paradigm. LEVEL OF EVIDENCE: Level V, review article.

Persistent knee extension deficits are common after anterior cruciate ligament reconstruction: a systematic review and meta-analysis of randomised controlled trials

PURPOSE

Knee extension deficits complicate recovery from ACL injury and reconstruction; however, the incidence of knee extension loss is not well defined. The aim of this review was to identify the incidence of loss of extension (LOE) following ACL rupture and reconstruction, explore the definitions of knee extension deficits reported and identify prognostic factors affecting LOE incidence.

METHODS

A systematic search was conducted in Medline, Cochrane Library and PEDro for studies in publication up to November 2021, with no restrictions on publication year. References were screened and assessed for inclusion using predetermined eligibility criteria. Randomised controlled trials (RCTs) that quantified knee angle, loss of extension or incidence of extension deficit were included for quality assessment and data extraction. Statistical summaries were generated and meta-analyses performed in two parts to examine: (i) the probability of a datapoint being zero incidence compared to a nonzero incidence and (ii) the relationship between the predictors and nonzero LOE incidence.

RESULTS

A sample of 15,494 studies were retrieved using the search criteria, with 53 studies meeting eligibility criteria. The pooled results from 4991 participants were included for analysis, with 4891 participants who had undergone ACLR. The proportion of included studies judged at an overall low risk of bias was small (7.8%). The observed group and study were the most important predictors for whether a datapoint reported an incidence of extension deficit. Time to follow-up (P < 0.001) and graft type (P = 0.02) were found to have a significant influence on nonzero LOE incidence (%). Covariate adjusted estimates of average LOE indicated 1 in 3 patients presenting with LOE at 12 month follow-up, reducing to 1 in 4 at 2 years.

CONCLUSIONS

This review examined the definitions for the measurement and interpretation of postoperative knee extension and established the trajectory of knee extension deficit after ACL injury and reconstruction. While factors associated with loss of extension were identified, the exact trajectory of knee extension deficits was difficult to infer due to discrepancies in measurement techniques and patient variation. On average, 1 in 3 patients may present with loss of extension of at least 3 degrees at 12-month follow-up, decreasing to 1 in 4 at 2 years. These results may be used by clinicians as an upper threshold for acceptable complication rates following ACLR. Future work should focus on LOE as a clinically relevant complication of ACL injury and treatment with appropriate attention to standardisation of definitions, measurements and better understanding of natural history.

PROSPERO REGISTRATION NUMBER

CRD42018092295.

LEVEL OF EVIDENCE

Level I.

Transtibial Versus Anteromedial Portal Technique for Femoral Tunnel Drilling in Primary Single-Bundle Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Level 1 and 2 Evidence of Clinical, Revision, and Radiological Outcomes

BACKGROUND

Although numerous clinical studies have compared transtibial (TT) and anteromedial portal (AMP) drilling of femoral tunnels during anterior cruciate ligament reconstruction (ACLR), there is no high-quality, evidence-based consensus regarding which technique affords the best outcome.

HYPOTHESIS

There would be no difference between the TT and AMP techniques in terms of knee stability, patient-reported outcomes, incidence of revision, and radiological results.

STUDY DESIGN

Meta-analysis; Level of evidence, 2.

METHODS

The PubMed and EMBASE databases were searched from inception to February 1, 2021. Level 1 and 2 clinical trials that compared TT and AM techniques were included. Data were meta-analyzed for the outcome measures of knee stability, patient-reported functional outcomes, incidence of revision, and radiological results. Dichotomous variables were presented as odds ratios (ORs), and continuous variables were presented as mean differences (MDs) and standard mean differences (SMDs).

RESULTS

The meta-analysis included 18 clinical studies, level of evidence 1 or 2, that involved 53,888 patients. Pooled data showed that the AMP group had a lower side-to-side difference (SMD, 0.22; 95% CI, 0.06 to 0.39; P = .009), a lower incidence of pivot-shift phenomenon (OR, 3.69; 95% CI, 1.26 to 10.79; P = .02), and a higher postoperative Lysholm score (SMD, -0.26; 95% CI, -0.44 to -0.08; P = .005) than the TT group. However, no statistically significant differences were seen in other outcomes, including subjective International Knee Documentation Committee scores (SMD, -0.11; 95% CI, -0.30 to 0.09; P = .30) or grades (OR, 0.93; 95% CI, 0.35 to 2.49; P = .89), postoperative activity level (MD, -0.14; 95% CI, -0.42 to 0.15; P = .35), and incidence of revision ACLR (OR, 1.04; 95% CI, 0.93 to 1.16; P = .45). The TT technique was more likely to create longer (SMD, 1.05; 95% CI, 0.05 to 2.06; P = .04) and more oblique (SMD, 0.81; 95% CI, 0.51 to 1.11; P < .001) femoral tunnels than the AMP technique, and a higher height ratio of the aperture position was detected with the TT technique (SMD, -3.51; 95% CI, -5.54 to -1.49; P < .001).

CONCLUSION

The AMP technique for ACLR may be more likely to produce better knee stability and improved clinical outcomes than the TT technique, but no difference was found in the incidence of revision between the 2 groups.

Anteromedial Portal Technique, but Not Outside-in Technique, Is Superior to Standard Transtibial Technique in Knee Stability and Functional Recovery After Anterior Cruciate Ligament Reconstruction: A Network Meta-analysis

PURPOSE

To compare the postoperative outcomes of 4 different femoral drilling techniques in anterior cruciate ligament reconstruction.

METHODS

Three databases were searched for randomized controlled trials comparing any 2 or more of the following femoral drilling techniques in anterior cruciate ligament reconstruction: standard transtibial (sTT), anteromedial portal (AMP), outside-in (OI), or modified transtibial (mTT) technique. A Bayesian network meta-analysis was performed to assess postoperative stability and functional recovery in terms of the side-to-side difference (measured by arthrometry), Lachman test, pivot-shift test, International Knee Documentation Committee subjective and objective scores, Lysholm score, and Tegner score. The Fisher exact probability test and χ² test were used to compare the incidences of infection and graft rupture, respectively.

RESULTS

We included 20 randomized controlled trials involving 1,515 patients. The AMP technique showed a lower side-to-side difference (standardized mean difference, -0.33; 95% credible interval [CrI], -0.53 to -0.12), higher negative rate on the pivot-shift test (odds ratio, 2.19; 95% CrI, 1.38 to 3.44), and higher International Knee Documentation Committee objective score (odds ratio, 3.13; 95% CrI, 1.42 to 7.82) than the sTT technique. However, knee stability and functional outcomes did not differ significantly between the OI and sTT techniques. Safety outcomes of the mTT technique were unavailable. The incidence of graft rupture was 5.20% for the OI technique, 2.27% for the AMP technique, and 1.51% for the sTT technique. The OI technique had a significantly higher incidence of graft rupture than the sTT technique (χ² = 4.421, P = .035). No significant difference in the incidence of infection was found between the sTT, AMP, and OI techniques (P = .281).

CONCLUSIONS

The AMP technique, but not the OI technique, was superior to the sTT technique in knee stability and functional recovery. The OI technique had a higher incidence of graft rupture than the sTT technique. There was no significant difference between the AMP and OI techniques or between the mTT technique and any other femoral drilling technique.

LEVEL OF EVIDENCE

Level II, meta-analysis of Level I and II studies.

The incidence of tibial tunnel coalition is higher than femoral tunnel coalition in double-bundle anterior cruciate ligament reconstruction using hamstring autografts: A systematic review

INTRODUCTION

Intra-operative and postoperative coalition of tunnels may occur in double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). However, the incidence and effect on clinical outcomes of tunnel coalition following primary DB ACLR using a hamstring autograft has yet be analyzed, and thus remains unknown. The objective of this systematic review was to identify the incidence of tunnel coalition upon DB ACLR using hamstring autografts and to elucidate any clinical outcomes and/or complications that tunnel coalition may have postoperatively.

HYPOTHESIS

The incidence of tunnel coalition would increase in respect to time from the index surgery, and that tunnel coalition would be related to poorer clinical outcomes compared to non-coalition cases.

METHODS

Three databases (PubMed, EMBASE, Cochrane Library) were searched in accordance with PRISMA and R-AMSTAR guidelines on June 15, 2020. Relevant studies were screened in duplicate and data regarding patient demographics, incidence of femoral and tibial tunnel coalition, and outcomes were extracted. Coalition rate was also compared between follow up at 1 month or less defined as "shorter-term", and 6 months or greater as "longer-term". Coalition is defined as the missing of a bony bridge between the two tunnels.

RESULTS

Thirty-six studies examining 1,574 patients, mean age 29.1 years, were included in this study. 29 studies (1,110 knees) reported the incidence of femoral coalition with a pooled rate of coalition of 8% (95% CI=4-12%). 28 studies (1,129 knees) reported an incidence of tibial coalition with a pooled rate of coalition of 21% (95% CI=13-30%). The incidence of tibial coalition was significantly higher than the incidence of femoral coalition across 21 comparative studies (OR=3.37, 95% CI=1.41-8.09, p=0.0065). Only two studies (111 knees) compared tunnel coalition and non-coalition groups for clinical outcome and no significant differences were observed with regards to Lysholm score, Tegner activity scale, and knee laxity measured with a KT-1000 arthrometer.

DISCUSSION

The rate of tibial tunnel coalition in DB ACLR is higher than femoral tunnel coalition, particularly at longer-term follow-up. Despite the higher radiographic evidence of coalition, the clinical effects of such remain to be ascertained, and further comparative studies are required to facilitate this understanding.

LEVEL OF EVIDENCE

IV, systematic review.

Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Is Not Superior to Anatomic Single-Bundle Reconstruction at 10-Year Follow-up: A Randomized Clinical Trial

BACKGROUND

The anatomic double-bundle (DB) technique is purported to be a superior technique due to its mimicking of the double-stranded anatomic formation of the anterior cruciate ligament (ACL). Previous studies with 2-, 5- and 10-year follow-up are conflicted as to whether this technique is superior to the previous gold standard method of ACL reconstruction, the anatomic single-bundle (SB) reconstruction.

PURPOSE/HYPOTHESIS

The aim of this prospective randomized study was to compare the outcomes of the anatomic DB technique and anatomic SB technique with independent drilling at 10 years after anterior cruciate ligament (ACL) reconstruction. We hypothesized that DB ACL reconstruction would result in a better outcome in terms of the pivot-shift test.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 105 patients (33 women, 72 men; median age, 27 years [range, 18-52 years]) were randomized and underwent ACL reconstruction (DB group: n = 53; SB group: n = 52). All reconstruction procedures were performed anatomically by identifying the ACL footprint, using the anteromedial portal for femoral tunnel drilling, and utilizing interference screws for tibial and femoral fixation. One blinded observer examined the patients both preoperatively and at follow-up (median, 120 months [range, 112-134 months]). Multiple subjective and objective clinical evaluations were used to assess the outcomes. Radiographic assessments of osteoarthritis were performed using the Ahlbäck, Kellgren-Lawrence, and Fairbank classification systems early postoperatively and at the final follow-up.

RESULTS

Preoperatively, no differences were found between the study groups. Overall, 70 patients (67%; DB group: n = 39; SB group: n = 31) were available for analysis at 10-year follow-up. No significant difference could be shown between the groups in terms of the pivot-shift grade, knee laxity measurements using the KT-1000 arthrometer, manual Lachman grade, single-leg hop test result, range of motion measurements, Lysholm knee score, Tegner activity score, and Knee injury and Osteoarthritis Outcome Score (KOOS) score. Correspondingly, no differences were found between the groups regarding the presence of radiographic osteoarthritis at follow-up. Both groups improved at follow-up compared with preoperatively in terms of the pivot-shift grade, knee laxity measurements using the KT-1000 arthrometer, manual Lachman grade, Lysholm knee score, and KOOS score (P < .05 [highest P value for any comparison]).

CONCLUSION

The anatomic DB technique was not superior to the anatomic SB technique with independent drilling at 10-year follow-up in regard to objective and subjective measurements. As such, one could argue that there is no need for the continued use of the anatomic DB technique in an unselected population.

Single Bundle Versus Double Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) tear is considered as one of the most common sport-related musculoskeletal injuries. Double bundle (DB) and single bundle (SB) surgical techniques has been widely adopted for ACL reconstruction. This systematic review aimed to provide updated evidence by comparing the short-term, mid-term, and long-term knee stability and functional outcomes of DB and SB reconstruction techniques.

Methods

We searched Medline, Web of Science, and CENTRAL. We have selected randomized controlled trials (RCTs) that compared DB and SB ACL reconstruction techniques for primary isolated ACL tear. We have assessed the following outcomes: pivot shift test, Lachman test, KT-1000/2000 knee ligament arthrometer, Lysholm knee function score, Tegner activity score, and graft failure. We have used the standardized mean difference (SMD) was to summarize the continuous outcomes while risk ratio (RR) was used to summarize the dichotomous outcomes.

Results

A total of 34 RCTs that enrolled 2,992 participants deemed eligible. Overall, DB showed significantly better outcomes in terms of pivot shift test (RR = 0.61, 95% confidence interval (CI) 0.49-0.75), Lachman test (RR = 0.77, 95% CI 0.62 to 0.95), and KT 1000/2000 arthrometer (SMD = - 0.21, 95% CI - 0.34 to - 0.08). No discernible difference was found between DB and SB techniques in the overall Lysholm score (SMD = 0.12, 95% CI - 0.03 to 0.27), Tegner score (SMD = 0.03, 95% CI - 0.17 to 0.24), or graft failure rate (RR = 0.78, 95% CI 0.33 to 1.85).

Conclusions

Our review suggests that DB ACL reconstruction technique shows significantly better knee stability and functional outcomes than SB at short-term follow-up. However, both techniques exhibit similar outcomes at mid-term and long-term follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00718-0.

Single versus double hamstring tendon graft in anterior cruciate ligament reconstruction in the paediatric patient: a single-blind randomised controlled trial study protocol

INTRODUCTION

There is currently no clear indication in the literature regarding a single or double hamstring tendon (single bundle) autograft for anterior cruciate ligament (ACL) reconstruction in the paediatric patient. The primary aim of this single blind randomised controlled trial is to determine whether a single or double hamstring tendon graft ACLR leads to superior clinical outcomes postsurgery in paediatric patients with ACL injury.

METHODS AND ANALYSIS

Single site, prospective, single blind, randomised controlled trial with two parallel treatment arms. 100 patients aged 10-18 years who present with an isolated ACL tear±meniscal injury, verified on MRI, will be randomly allocated to one of the two surgical groups. The primary outcomes will be side-to-side difference in anterior tibial translation and graft failure incidence 12 months postsurgery. Primary and secondary outcomes will also be assessed at 2-year and 5-year postsurgery.

ETHICS AND DISSEMINATION

Results will be presented in peer-reviewed journals and at international conferences and disseminated to participants and healthcare professionals via newsletters and hospital presentations. This study is approved by the Children's Health Queensland Hospital and Health Service Human Research Ethics committee.

TRIAL REGISTRATION NUMBER

ACTRN12620001170910p; Australian New Zealand Clinical Trials Registry.

Evaluation of Tibial Tunnel Location with the Femoral Tunnel Created Behind the Resident's Ridge in Transtibial Anterior Cruciate Ligament Reconstruction

Few studies have determined whether a femoral bone tunnel could be created behind the resident's ridge by using a transtibial (TT) technique-single bundle (SB)-anterior cruciate ligament (ACL) reconstruction. The aim of this study was to clarify (1) whether it is possible to create a femoral bone tunnel behind the resident's ridge by using the TT technique with SB ACL reconstruction, (2) to define the mean tibial and femoral tunnel angles during anatomic SB ACL reconstruction, and (3) to clarify the tibial tunnel inlet location when the femoral tunnel is created behind resident's ridge. Arthroscopic TT-SB ACL reconstruction was performed on 36 patients with ACL injuries. The point where 2.4-mm guide pin was inserted was confirmed, via anteromedial portal, to consider a location behind the resident's ridge. Then, an 8-mm diameter femoral tunnel with a 4.5-mm socket was created. Tunnel positions were evaluated by using three-dimensional computed tomography (3D-CT) 1 week postoperatively. Quadrant method and the resident's ridge on 3D-CT were evaluated to determine whether femoral tunnel position was anatomical. Radiological evaluations of tunnel positions yielded mean ( ±  standard deviation) X- and Y-axis values for the tunnel centers: femoral tunnel, 25.2% ± 5.1% and 41.6% ± 10.2%; tibial tunnel, 49.2% ± 3.5%, and 31.5% ± 7.7%. The bone tunnels were anatomically positioned in all cases. The femoral tunnel angle relative to femoral axis was 29.4 ± 5.5 degrees in the coronal view and 43.5 ± 8.0 degrees in the sagittal view. The tibial tunnel angle relative to tibial axis was 25.5 ± 5.3 degrees in the coronal view and 52.3 ± 4.6 degrees in the sagittal view. The created tibial bone tunnel inlet had an average distance of 13.4 ± 2.7 mm from the medial tibial joint line and 9.7 ± 1.7 mm medial from the axis of the tibia. Femoral bone tunnel could be created behind the resident's ridge with TT-SB ACL reconstruction. The tibial bone tunnel inlet averaged 13.4 mm from the medial tibial joint line and 9.7 mm medial from the tibia axis.

Association Between Early Postoperative Graft Signal Intensity and Residual Knee Laxity After Anterior Cruciate Ligament Reconstruction

Background:

Magnetic resonance imaging (MRI) graft signal intensity is associated with graft damage after anterior cruciate ligament reconstruction (ACLR). However, little is known about the relationship between graft signal intensity and residual laxity of the reconstructed knee based on patient age.

Purpose/Hypothesis:

To evaluate the relationship between graft signal intensity and residual laxity in younger and older patients who underwent ACLR. We hypothesized that higher graft signal intensity would be associated with reduced postoperative knee stability.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 192 patients who underwent double-bundle ACLR were recruited. Proton density–weighted and T2-weighted MRI was performed at 3, 6, and 12 months after surgery, and the signal intensity ratio (SIR) of the anteromedial and posterolateral bundles was measured as the graft signal intensity reference values. At 12 months after surgery, if the KT-1000 arthrometer measurement exhibited a side-to-side difference of ≥2 mm, the patient was determined as having anterior knee laxity. Rotatory knee laxity was defined as a positive pivot shift with International Knee Documentation Committee grade ≥1. The Mann-Whitney U test was used to compare the SIR in patients with and without residual laxity. The Spearman correlation coefficient was used to evaluate the relationship between demographic parameters and the SIR. Based on receiver operating characteristic curves, the optimal SIR cutoff values to predict residual laxity were calculated, and logistic regression analysis was conducted.

Results:

Of 192 patients, 26 (13.5%) had anterior knee laxity, and 20 (10.4%) had rotatory knee laxity. The SIR was negatively correlated with age. In younger patients (<30 years; n = 135), those with residual laxity had a significantly higher SIR than those without laxity; this relationship was not significant in older patients (≥30 years; n = 57). Based on receiver operating characteristic curves and logistic regression analysis, the cutoff values that were determined for the SIR were significantly associated with a higher odds ratio of residual laxity.

Conclusion:

Graft signal intensity decreased with patient age. Patients with higher graft signal intensity in the early postoperative phase after ACLR exhibited a higher prevalence of residual laxity, particularly in younger patients.

Arthroscopic reconstruction of anterior cruciate ligaments with allograft: single-tunnel single-bundle versus single-tunnel double-bundle techniques

Purpose

To compare the clinical results of anterior cruciate ligament (ACL) reconstruction using the single-tunnel single-bundle (STSB) technique versus the single-tunnel double-bundle (STDB) technique.

Methods

This was a retrospective, single-center, single-surgeon study based on data collected from March 2012 to June 2013. According to our inclusion/exclusion criteria, a total of 78 patients (64 males, 14 females; mean age, 25.1 years) who underwent arthroscopic ACL reconstruction with anterior tibialis tendon allografts through either the STSB technique (36 cases) or the STDB technique (42 cases) in our department were recruited. The International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores were used to evaluate the subjective function of the knee joint during the postoperative follow-up. The Lachman test and pivot shift test were used to objectively assess the stability of the knee.

Results

The average follow-up duration was 24.9 ± 1.8 months in the STSB group and 24.6 ± 1.7 months in the STDB group (P > 0.05). Patients in both groups recovered to the preoperative sports level with few complications. The postoperative Lysholm score (86.1 ± 7.5 vs. 47.7 ± 9.0 in the STSB group; 87.0 ± 7.1 vs. 48.2 ± 8.3 in the STDB group), IKDC score (87.8 ± 7.2 vs. 49.3 ± 6.1 in the STSB group; 88.7 ± 6.6 vs. 49.8 ± 6.3 in the STDB group), Tegner score (6.5 ± 1.3 vs. 2.5 ± 1.3 in the STSB group; 6.6 ± 1.2 vs. 2.6 ± 1.2 in the STDB group), Lachman test positive rate (8.3% vs. 89.9% in the STSB group; 7.1% vs. 85.7% in the STDB group), and pivot shift test positive rate (27.8% vs. 63.9% in the STSB group; 7.1% vs. 69.0% in the STDB group) were significantly improved compared to the preoperative status in both groups (P < 0.05). However, no statistically significant difference was observed between the two groups at the final follow-up (P > 0.05), except for the pivot shift test positive rate in the STDB group versus the STSB group (7.1% vs. 27.8%, P < 0.05).

Conclusions

The STDB technique achieved a satisfactory clinical outcome with better rotational stability compared to the traditional STSB technique and therefore provided an effective option for ACL reconstruction.

Level of evidence

Case series, Level IV.

Anterior cruciate ligament foot plate anatomy: 3-dimensional and 2-dimensional MRI evaluation with arthroscopy assessment in a subset of patients

OBJECTIVES

ACL reconstruction tunnel location is an important predictor for outcomes after surgery. The aim was to establish 3D and 2D MRI radiological measurements for native ACL tibial footprint that can provide information to facilitate pre-operative planning for anatomical graft placement. The measurements were also correlated in a subset of patients on arthroscopy.

METHODS

Retrospective evaluation of a consecutive series of knee MRIs with both 2D and 3D MR imaging was performed in 101 patients with 43 men and 66 women and ages 39.5 ± 11.9 years. Two measurements were obtained, tibial to ACL and intermeniscal ligament to ACL (T-ACL) and (IM-ACL), respectively. In a cohort of 18 patients who underwent knee arthroscopy, the T-ACL and IML-ACL distances were also determined by an orthopedic surgeon using a standard scale. ICC, Pearson correlation, and Bland-Altman plot were generated.

RESULTS

For readers 1 and 2, the mean differences between 2D and 3D measurements of T-ACL and IM-ACL were 1.17 and 1.03 mm and 0.65 and 0.65 mm, respectively. The 2D measurements of T-ACL and IM-ACL were larger than the 3D measurements for both readers. The inter-reader reliability was excellent on 2D (0.81-0.96) and fair to excellent on 3D MRI (0.59-0.90). The mean arthroscopic IML-ACL was closer to that of 3D MRI compared to 2D MRI. The mean arthroscopic T-ACL was closer to 2D MRI than 3D MRI.

CONCLUSIONS

Both 2D and 3D MRI show inter-reader reliability with small inter-modality mean differences in the measurements from the tibial or inter-meniscal ligament margins.

KEY POINTS

• The mean differences between 2D and 3D measurements of tibia-ACL and intermeniscal ligament-ACL are small (< 1.2 mm). • As compared to arthroscopy, the mean T-ACL and IML-ACL were closer to measurements from 2D and 3D MRI, respectively. • Both 2D and 3D MRI can be reliably used to delineate ACL foot plate anatomy.

Radiological maturation and clinical results of double-bundle and single-bundle anterior cruciate ligament reconstruction. A 5-year prospective case-controlled trial

INTRODUCTION

The aim of the study was to make a prospective comparison of the radiological and clinical outcomes of patients undergoing single-bundle and double-bundle anterior cruciate ligament (ACL) reconstruction.

METHOD

This prospective, case-controlled study included 65 patients, separated into 2 groups as 33 patients undergoing single bundle (SB), and 32 patients undergoing double bundle (DB) ACL reconstruction. The patients were evaluated clinically using the International Knee Documentation Committee (IKDC) and the Lysholm knee scores. Stability was evaluated with the KT-1000 Arthrometer Measurement, the Lachman and pivot shift tests. Magnetic resonance images (MRI) at 1 and 5 years postoperatively were evaluated by a musculoskeletal radiologist. All the operations were performed by a single surgeon and the clinical evaluations were made by an independent researcher.

RESULTS

Evaluation was made of a total of 53 patients (SB: 28, DB: 25). No statistically significant difference was determined between the groups regarding the postoperative IKDC and Lysholm scores. The pivot shift tests were negative in the DB group and positive in two patients of the SB group. The Lachman test was negative in all the patients. No significant difference was determined between the groups. No statistically significant difference was determined between the two groups in respect of the arthrometer measurements. In the SB group, revision surgery was performed in two patients due to graft failure. No graft failure findings were determined in the DB group, and no statistically significant difference was determined between the groups in respect of graft failure. On the MRIs taken at 1 year postoperatively, the ACL was seen to be hyperintense in 16 patients in the DB group and 6 patients in the SB group (p = 0.004). On the 5-year MRIs, ACL hypointensity could not be seen in three patients of the SB group and two of the DB group, with no difference determined between the groups (p > 0.05).

CONCLUSION

In the 5-year follow-up period, no difference was determined between patients undergoing SB ACL reconstruction and those undergoing DB ACL reconstruction regarding clinical scores, knee stability, and MRI findings, but graft maturation occurs later the patients undergoing DB reconstruction.

Biomechanical Evaluation of Suture Tape Internal Brace Reinforcement of Soft Tissue Allografts for ACL Reconstruction Using a Porcine Model

Background:

Internal bracing of anterior cruciate ligament (ACL) surgery is a newer concept gaining popularity.

Purpose/Hypothesis:

To assess the biomechanical performance of soft tissue ACL reconstruction allografts reinforced with suture tape. It was hypothesized that load to failure would increase and cyclic displacement would decrease at time zero in the constructs reinforced with internal brace suture tape compared with those without suture tape augmentation.

Study Design:

Controlled laboratory study.

Methods:

We performed ACL reconstruction on porcine knees using bovine extensor tendon soft tissue allografts: 10 knees without (control) and 10 knees with (reinforced) suture tape reinforcement. An all-inside reconstruction technique was utilized with retrograde tunnel creation. An adjustable-loop device was used for femoral and tibial fixation of all grafts. The suture tape was placed through the tension loop in the femoral fixation construct and independently fixed in the tibia with an interference screw anchor. For each specimen, the authors recorded ultimate load, yield load, stiffness, cyclic displacement, and mode of failure. Outcomes between groups were compared using the Student t test.

Results:

There was a 33% decrease in mean cyclic displacement in the specimens with reinforced grafts (reinforced vs control: 3.9 ± 0.7 vs 5.8 ± 1.5 mm; P = .001). The reinforced grafts also had a 22% higher mean ultimate load (921 ± 180 vs 717 ± 122 N; P = .008) and a 25% higher mean yield load (808 ± 201 vs 602 ± 155 N; P = .020). There was no significant difference in stiffness between the reinforced versus nonreinforced grafts (136 ± 16 vs 132 ± 18 N/mm; P = .617). Three of the 10 control specimens failed at the graft, compared with 1 of 10 reinforced grafts. All other constructs in both groups failed at the tibial fixation site.

Conclusion:

Suture tape reinforcement of soft tissue grafts significantly decreased cyclic displacement while significantly increasing ultimate and yield loads without increasing graft construct stiffness during biomechanical testing at time zero in a porcine animal model.

Clinical Relevance:

The improved biomechanical performance of suture tape–reinforced graft constructs could allow patients to participate in earlier advancement of aggressive rehabilitation and potentially reduce failure rates as graft remodeling progresses.

Similar outcomes and satisfaction after transtibial versus transportal femoral drilling for anterior cruciate ligament reconstruction in young adult recreational athletes

PURPOSE

Controversy continues regarding whether the transtibial (TT) and transportal (TP) methods for anterior cruciate ligament (ACL) reconstruction provide similar or different outcomes, and the evidence on patient satisfaction is very limited. The objective of this study was to compare functional outcomes and patient satisfaction in young adult recreational athletes who underwent arthroscopic hamstring ACL reconstruction using either the TT or the TP femoral tunnel drilling method.

METHODS

A nonrandomized prospective study was designed to compare the outcomes of arthroscopic hamstring ACL reconstruction using TT or TP method. Functional outcome was assessed with the Lyshom score, and patient satisfaction with a 5-point Likert scale. Knee stability was measured with the KT-1000 arthrometer.

RESULTS

42 patients in the TT group and 41 in TP group, with age ranged 18-40 years, were compared with a mean follow-up of 42 (range 24-60) months. There were no significant differences between groups in the Lysholm score (n.s.), sport return rate (n.s.) or patient satisfaction with the surgery (n.s.). Satisfaction was only significantly associated with the Lysholm score (OR 1.3; IC 95% 1.06-1.6; p = 0.012), but not with the return to sports (n.s.) or knee anterior laxity (n.s.).

CONCLUSION

This study showed no statistical differences between the TT and the TP method in functional outcomes or patient satisfaction in young adult recreational athletes. In those patients, satisfaction with the surgery was not influenced by the return to sport activities. This study can guide surgeons in the decision-making for ACL reconstruction in recreational athletes.

LEVEL OF EVIDENCE

Level II.

Non-anatomic tunnel position increases the risk of revision anterior cruciate ligament reconstruction

PURPOSE

Anterior cruciate ligament (ACL) graft failure is a complication that may require revision ACL reconstruction (ACL-R). Non-anatomic placement of the femoral tunnel is thought to be a frequent cause of graft failure; however, there is a lack of evidence to support this belief. The purpose of this study was to determine if non-anatomic femoral tunnel placement is associated with increased risk of revision ACL-R.

METHODS

After screening all 315 consecutive patients who underwent primary single-bundle ACL-R by a single senior orthopedic surgeon between January 2012 and January 2017, 58 patients were found to have both strict lateral radiographs and a minimum of 24 months follow-up without revision. From a group of 456 consecutive revision ACL-R, patients were screened for strictly lateral radiographs and 59 patients were included in the revision group. Femoral tunnel placement for each patient was determined using a strict lateral radiograph taken after the primary ACL-R using the quadrant method. The center of the femoral tunnel was measured in both the posterior-anterior (PA) and proximal-distal (PD) dimensions and represented as a percentage of the total distance (normal center of anatomic footprint: PA 25% and PD 29%).

RESULTS

In the PA dimension, the revision group had significantly more anterior femoral tunnel placement compared with the primary group (38% ± 11% vs. 28% ± 6%, p < 0.01). Among patients who underwent revision; those with non-traumatic chronic failure had statistically significant more anterior femoral tunnel placement than those who experienced traumatic failure (41% ± 13% vs. 35% ± 8%, p < 0.03). In the PD dimension, the revision group had significantly more proximal femoral tunnel placement compared with the primary group (30% ± 9% vs 38% ± 9%, p < 0.01).

CONCLUSION

In this retrospective study of 58 patients with successful primary ACL-R compared with 59 patients with failed ACL-R, anterior and proximal (high) femoral tunnels for ACL-R were shown to be independent risk factors for ACL revision surgery. As revision ACL-R is associated with patient- and economic burden, particular attention should be given to achieving an individualized, anatomic primary ACL-R. Surgeons may reduce the risk of revision ACL-R by placing the center of the femoral tunnel within the anatomic ACL footprint.

LEVEL OF EVIDENCE

Level III.

A Modified Anatomic Transtibial Double-Bundle Anterior Cruciate Ligament Reconstruction Provides Reliable Bone Tunnel Positioning

Purpose

To evaluate the femoral and tibial tunnel positions via a modified anatomic transtibial double-bundle anterior cruciate ligament (ACL) reconstruction.

Methods

Patients who underwent double-bundle ACL reconstruction using the transtibial tunnel creation technique were identified. Double-bundle ACL reconstruction was performed for 94 knees using the transtibial tunnel creation technique. Tunnel aperture configurations and center positions of the anteromedial (AM) and posterolateral (PL) tunnels via postoperative 3-dimensional computed tomography were evaluated.

Results

There were 94 knees included. Regarding the intra-articular tunnel aperture configurations, the AM and PL tunnels overlapped at the femoral and tibial aperture in 66.0% and 94.7% cases, respectively. The mean femoral bone tunnel center was located at 23.0 ± 3.9% in the posterior-to-anterior ratio and 28.7 ± 6.0% in the proximal-to-distal ratio for the AM tunnels and at 32.8 ± 4.7% and 51.2 ± 5.2% for the PL tunnels, respectively. In the tibial tunnels, the mean AM tunnel center was located at 31.4 ± 3.6% in the anterior-to-posterior ratio and 44.3 ± 1.8% in the medial-to-lateral ratio and at 47.5 ± 3.8% and 44.3 ± 1.9% in the PL tunnel center, respectively. The femoral tunnels of outliers, both those created in nonanatomic positions as well as the posterior wall blowouts, were revealed in 7.4% cases. The nonanatomical bone tunnel group had significant heavier weight patients, lower tibial posterior slope, and were anterior in the AM and PL tunnel position. Posterior wall blowouts were related to posterior and proximal PL bone tunnel positions.

Conclusions

Modified transtibial double-bundle ACL reconstruction is a reliable tunnel creation technique with anatomic placement in 92.6% of the cases. The modification required that partially superimposing configuration of the 2 tibial tunnel apertures. The nonanatomic tunnels were related to patients of heavier weight and lower tibial posterior sloped knees, whereas the posterior wall blowouts were related to the posterior and proximal PL bone tunnel positions.

Level of Evidence

Level IV, therapeutic case series.

Better Coverage of the ACL Tibial Footprint and Less Injury to the Anterior Root of the Lateral Meniscus Using a Rounded-Rectangular Tibial Tunnel in ACL Reconstruction: A Cadaveric Study

Background

To better restore the anatomy of the native anterior cruciate ligament (ACL) attachment and fiber arrangement, researchers have developed techniques for changing the shape of the ACL bone tunnel during ACL reconstruction.

Purpose

To compare the coverage of the ACL tibial footprint and influence on the anterior root of lateral meniscus (ARLM) between a rounded-rectangular tibial tunnel and a conventional round tibial tunnel for ACL reconstruction.

Study Design

Controlled laboratory study.

Methods

A total of 16 (8 matched-paired) fresh-frozen human cadaveric knees were distributed randomly into 2 groups: a rounded-rectangular tunnel (RRT) group and a round tunnel (RT) group. One of the knees from each pair was reamed with rounded-rectangular tibial tunnel, whereas the other was reamed with round tibial tunnel. Coverage of the ACL tibial footprint and areas of ARLM attachment before and after reaming were measured using 3-dimensional isotropic magnetic resonance imaging.

Results

In the RRT group, the average percentage of ACL tibial footprint covered by the tunnel was 70.8% ± 2.5%, which was significantly higher than that in the RT group (48.2% ± 6.4%) (P = .012). As for the ARLM attachment area, in the RT group, there was a significant decrease (22.5% ± 5.9%) in ARLM attachment area after tibial tunnel reaming compared with the intact state (P < .001). Conversely, in the RRT group, the ARLM attachment area was not significantly affected by tibial tunnel reaming.

Conclusion

Rounded-rectangular tibial tunnel was able to better cover the native ACL tibial footprint and significantly lower the risk of iatrogenic injury to the ARLM attachment than round tibial tunnel during ACL reconstruction.

Single-Tunnel Double-Bundle-Like Effect With Footprint Enhancing Anterior Cruciate Ligament Reconstruction

The anterior cruciate ligament (ACL) consists of an anteromedial bundle and a posterolateral bundle giving anteroposterior and rotational stability. It's one of the most commonly injured ligaments and also one of the most commonly performed arthroscopic procedures. Management of ACL injuries is one of the most frequently studied subjects in the literature. Surgical management of ACL injuries varies from extraarticular tenodesis to arthroscopic transtibial reconstruction to double-bundle reconstruction to anatomic single-bundle reconstruction. Although double-bundle ACL reconstruction gives more rotational stability than anatomic single-bundle, functional outcome of both are the same, but the complication rates are much higher for double-bundle reconstruction. Hence, anatomic single-bundle ACL reconstruction has gained popularity. The femoral and tibial footprint of the ACL varies in shape and size; it can be oval, elliptical, rectangular, C-shape, and more. But all available ACL reconstruction techniques prepare a circular tunnel; hence, the footprint coverage of the native ACL is maximum after double-bundle reconstruction and less after anatomic single-bundle reconstruction. So, to have the benefit of double-bundle reconstruction with a single tunnel, we propose our technique of a single-tunnel double-bundle-like effect, with the footprint enhancing ACL reconstruction using our newly designed tunnel dilators.

Effect of Tunnel Drilling Portal on Femoral Tunnel Entry Aperture’s Location in Arthroscopic Anterior Cruciate Ligament Reconstruction

Introduction

Transportal techniques for femoral tunnel drilling have the advantage of anatomical anterior cruciate ligament reconstruction, which was earlier difficult to achieve through transtibial femoral tunnels. However, the medial arthroscopic portal used for femoral tunnel drilling in single-bundle anterior cruciate ligament reconstruction (ACLR) has not been uniformly placed in different studies. Therefore, we performed a computed tomography-based analysis to compare the femoral tunnel entry aperture of the ACLR cases that used the standard AM portal and those using a far medial portal for femoral tunnel drilling.

Methods

We retrospectively reviewed computed tomography images of patients who underwent isolated single-bundle ACLR in our institute with either standard anteromedial portal or the far medial portal used for the femoral tunnel drilling. The femoral tunnel aperture's depth and height, measured using the quadrant method, were compared between the two portal methods.

Results

A total of forty-two case records were reviewed, sixteen belonging to standard anteromedial portal technique and twenty-six belonging to far medial portal technique. The tunnels created through the far AM portal were significantly shallower (more anterior) and inferior than the standard AM portal-created femoral tunnels.

Conclusion

The choice of drilling portals can influence transportal femoral tunnel drilling. A tendency towards anterior and inferior positioning of the femoral tunnel entry aperture has been observed when a far medial arthroscopic portal is used for femoral tunnel drilling. Therefore, care must be taken to ensure that the drilling guide pin position does not change when the reamer is passed over it.

Freehand Anatomic Transtibial Single-Bundle Anterior Cruciate Ligament Reconstruction

Creation of the femoral tunnel for single-bundle anterior cruciate ligament (ACL) reconstruction has a high rate of nonanatomic placement with the transtibial (TT) technique but yields better restoration with the anteromedial portal technique and close restoration of the anatomic femoral footprint with the outside-in technique. Modifications of the traditional (TT) technique have been described to restore the native femoral ACL footprint and to simulate double-bundle reconstruction. Modified TT techniques try to capture the anatomic femoral footprint through an anatomic tibial tunnel. In the technique described in this article, the anatomic femoral footprint is drilled first by the use of a 2.5-mm Kirschner wire through the parapatellar anteromedial portal, making an angle 30° to the sagittal plane and 20° to the horizontal plane. The wire is drilled while the knee is hyperflexed and then withdrawn from outside until its distal end reaches the intercondylar notch. The wire is then advanced in an antegrade manner while the knee is flexed 90° until it reaches the center of the marked tibial footprint. The angle of knee flexion may be slightly increased or decreased around 90° with or without slight internal rotation to capture the anatomic tibial footprint. The procedure is completed as a TT single-bundle ACL reconstruction.

Double bundle ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than single bundle ACL reconstruction

PURPOSE

The purpose of this meta-analysis is to compare arthroscopic single bundle (SB) and double bundle (DB) anterior cruciate ligament (ACL) reconstructions in the light of all available randomised controlled trials (RCTs). A meta-analysis of this well-researched topic was performed and subgroup analyses of the medial portal (MP) technique and the transtibial technique (TT) were added as a new idea. The hypothesis was that the DB technique is superior to the SB technique also in subgroup analyses of the MP and TT techniques.

METHODS

Instructions of the PRISMA checklist were followed. Systematic literature search from electronic databases, including PubMed, Cochrane library and Scopus was performed to find RCTs that compared the SB and DB techniques. Nine outcomes were used to compare these two techniques. Each study was assessed according to the Cochrane Collaboration's risk of bias tool and three subgroup analyses (minimum 2-years' follow-up, TT technique and MP technique) were performed.

RESULTS

A total of 40 studies were included in this meta-analysis. When analysing all the included studies, the DB technique was superior to the SB technique in KT-1000/2000 evaluation (p < 0.01), IKDC subjective evaluation (p < 0.05), Lysholm scores (p = 0.02), pivot shift (p < 0.01) and IKDC objective evaluation (p = 0.02). Similar results were also found in the subgroup analyses of minimum 2-years' follow-up and the TT technique. However, there were no differences between the two techniques in a subgroup analysis of the MP technique.

CONCLUSION

Generally, DB ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than SB ACL reconstruction. The subgroup analysis of the MP technique revealed that surgeons can achieve equally as good results with both techniques when femoral tunnels are drilled through the medial portal.

LEVEL OF EVIDENCE

II.

Transportal versus all-inside techniques of anterior cruciate ligament reconstruction: a systematic review

Background

Transportal (TP) and all-inside techniques (AIT) are the most commonly used anterior cruciate ligament (ACL) reconstruction procedures in current clinical practice. However, there is an ongoing debate over which procedure is superior. Therefore, the purpose of this systematic review was to evaluate and compare the clinical outcomes and complications of these two techniques to propose recommendations for future application. Our primary hypothesis was that AIT is a superior ACLR technique compared to TP.

Methods

A systematic literature review, using PRISMA guidelines, was conducted using PubMed, Medline, Google Scholar, and EMBASE, up to February 2021 to identify studies focusing on AIT and TP techniques of ACL reconstruction. We excluded animal experiments, cadaveric studies, retrospective studies, case reports, technical notes, and studies without quantitative data. Patients’ characteristics, surgical technical features, along with postoperative follow-up and complications were extracted and reported accordingly. Methodological quality of the included studies was assessed using the Modified Coleman Methodology Score (MCMS).

Results

A total of 44 studies were selected for this review, of which four were comparative studies. A total of 923 patients underwent AIT and 1678 patients underwent the TP technique for ACLR. A single semitendinosus graft was commonly used in the AIT compard to combined semitendinosus and gracilis graft in the TP group. The postoperative increase in International Knee Documentation Committee (IKDC), Lysholm, KT-1000, and Short Form-12 (physical and mental) scores were similar in the AIT group and the TP group. Contrastingly, the VAS pain score was significantly lower in the AIT group compared to the TP group. Furthermore, the pooled complication rates from all studies were similar between the two groups (AIT: 54 patients, 8.26% vs. PT: 55 patients, 6.62%). However, the four studies that prospectively compared AIT and TP techniques showed lesser complications in the AIT group than the TP group.

Conclusion

Since the future trend in orthopedic surgery is toward less invasive and patients’ satisfaction with good outcomes, AIT is a good alternative method considering preserving bony tissue and gracilis tendon with less post-operative pain, along with more knee flexor strength and equal outcomes compared to conventional ACL reconstruction surgery.

Level of Evidence II.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02872-x.

Anatomic double-bundle anterior cruciate ligament reconstruction could not achieve sufficient control of pivot-shift when accompanying tibial tunnel coalition

PURPOSE

To evaluate the effect of tibial tunnel coalition on knee rotatory laxity and clinical outcomes after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Forty-one patients who underwent anatomic DB ACL reconstruction were included prospectively. Three-dimensional computed tomography of the knee joint was obtained at approximately 1 year postoperatively to determine if tunnel coalition occurred. After excluding seven cases of femoral tunnel coalition, two groups were established based on the existence of a tibial tunnel coalition. The pivot-shift test was quantitatively evaluated on the basis of tibial acceleration preoperatively and at 1 year postoperatively. Two subjective scores, the International Knee Documentation Committee (IKDC) subjective and Lysholm scores, were also collected. The pivot-shift measurement and subjective scores were compared between the ACL-reconstructed knees with and without tibial tunnel coalition. The independent t test, Pearson's chi-square test, and Student t tests were used in data analysis.

RESULTS

Twenty-one knees had tibial tunnel coalition (group C), whereas 13 knees did not have tunnel coalition(group N). Pivot-shift was significantly diminished postoperatively in both groups on the basis of the clinical examination and quantitative evaluations (p < 0.05). However, there was a small but significant difference in tibial acceleration demonstrating larger pivot-shift in group C (1.0 ± 0.6 m/s²) than in group N (0.5 ± 0.3 m/s², p < 0.05). No significant difference was observed in the IKDC subjective and Lysholm scores (both n.s.).

CONCLUSION

When the tibial tunnel coalition occurs after DB ACL reconstruction, knee rotatory laxity may not be restored in ACL-reconstructed knees, as expected in those without tunnel coalition. It is recommended that two tibial tunnels should be created separately when performing DB-ACL reconstruction to achieve better control of rotatory knee laxity.

LEVEL OF EVIDENCE

III.

Comparing post-operative pain between single bundle and double bundle anterior cruciate ligament reconstruction: a retrospective study

Background

In anterior cruciate ligament (ACL) reconstruction, the clinical outcome and level of post-operative pain are important factors. To date there have been no studies evaluating differences in post-operative pain between single bundle and double bundle ACL reconstruction with a hamstring graft.

Hypothesis/purpose

We hypothesized that post-operative pain in single bundle ACL reconstruction would be less than in double bundle ACL reconstruction. This study was to compare post-operative pain between patients undergoing single bundle versus double bundle ACL reconstruction.

Study design

Cohort study.

Methods

This was a retrospective study comparing post-operative pain scores between single bundle and double bundle ACL reconstruction. Each patient was given our standard regimen of oral diclofenac (25 mg/tab) three times per day and paracetamol (500 mg/tab) six times per day for 1 day post-operatively. If the patient complained of moderate to severe pain (pain numeric rating scale (PNRS) > 3), 3 mg of morphine was injected intravenously every 3 h for 24 h and 1 mg of morphine as a rescue medication every 1 h for 24 h. PNRS and morphine consumption were recorded at 4-h intervals for 24 h.

Results

209 patients were included in this study of whom 102 and 107 patients received single bundle and double bundle ACL reconstruction, respectively. The average post-operative pain scores of the single bundle group were lower at all time points. Linear mixed effect regression analyses showed that the single bungle group had lower post-operative pain than the double bundle group after adjusting for confounders (beta = − 0.45; 95% CI = − 0.838, − 0.062) but there was no statistically significant difference between numbers of bundle ACL reconstruction with regard to morphine consumption.

Conclusion

Single bundle ACL reconstruction had significantly lower post-operative pain scores than double bundle ACL reconstruction.

Clinical relevance

Double bundle ACL reconstruction results in higher post-operative pain, which may slow the start of rehabilitation and reduce patient satisfaction. In middle-aged adult patients with low-demand activities, we suggest performing a single bundle ACL reconstruction.

Double-bundle anterior cruciate ligament reconstruction technique has advantages in chondroprotection and knee laxity control compared with single-bundle technique : A long-term follow-up with a minimum of 12 years

PURPOSE

To compare the long-term clinical outcomes of single-bundle anterior cruciate ligament reconstruction (SBR) and double-bundle anterior cruciate ligament reconstruction (DBR) in patients with isolated anterior cruciate ligament (ACL) rupture, presenting no meniscus injury and no obvious preoperative cartilage degeneration.

METHODS

One hundred and three patients (38.6 ± 9.5 years) with a median follow-up of 151.6 months (range, 144-189 months) completed the retrospective study (SBR group: n = 51; DBR group: n = 52). Clinical outcomes were evaluated with physical examinations, KT-2000 anterior and posterior stability measurement with the knee in 30º of flexion, International Knee Documentation Committee (IKDC) subjective score, Tegner score, Lysholm score; magnetic resonance imaging (MRI) (3.0 T) was performed, and International Cartilage Repair Society (ICRS) cartilage degeneration grades were determined. Multivariate analysis was performed to identify factors associated with cartilage degeneration.

RESULTS

There were significant differences in the pre- and postoperative IKDC, Lysholm and Tegner scores between the SBR and DBR groups. The SBR group had over double the rate of positive pressure/rub patellar test results (SBR vs DBR, 43.1% vs. 19.2%, p < 0.011). The KT-2000, pivot-shift and Lachman test results were stratified and analyzed, and significant differences between the SBR and DBR groups were found (p < 0.05, respectively). The distribution of ICRS grades differed significantly between the groups at the last follow-up (p = 0.013). A multivariate analysis found that age and operation procedures were significant predictors of 0 and non-0 ICRS grades (odds ratio, 6.077 [95% CI 2.117-17.447] and 0.210 [95% CI 0.068-0.654], respectively) (p < 0.05).

CONCLUSION

Both SBR and DBR achieved overall good long-term results. DBR had advantages in objective outcome measures and was superior in preventing the occurrence of cartilage degeneration. Age was identified as a preoperative risk factor for significant postoperative cartilage degeneration.

LEVEL OF EVIDENCE

III. ClinicalTrials.gov: NCT03984474.

Editorial Commentary: Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction Makes More Sense Than Triple-Bundle: Three's a Crowd

Recent research reports impressive patient-reported and objective stability outcomes after triple-bundle anterior cruciate ligament (ACL) reconstruction with hamstring autograft. However, the results are similar to those reported in the orthopaedic literature for single-bundle ACL reconstruction. If the triple-bundle technique does not reduce graft failure rates, and bearing in mind that it is more complex, more expensive, and more difficult to revise, then an anatomically-positioned single-bundle ACL reconstruction makes more sense. If the data supporting double-bundle ACL reconstruction is inconclusive, then why add a third bundle?

Does anterolateral ligament injury change the treatment option in patients with partial ACL tears?

Patients with ACL tears with ALL injury have more clinical complaints (instability, feeling of the pop on the knee or knee sliding). patients have ALL injury with partial ACL tears, It is unclear whether the choice of treatment will be conservative or surgical. This study aimed to determine the effect of anterolateral ligament (ALL) status, whether intact or ruptured, on the choice of conservative or surgical treatment in patients with partial anterior cruciate ligament (ACL) tears. Between 2015 and 2019, patients with suspected partial ACL tears were identified on both physical examination and MR imaging. 122 patients who had partial ACL tears and also status of patient’s ALL could be evaluated by radiologist were included in the study, retrospectively. Sixty-two patients who underwent ACL reconstruction were determined as group 1, and 60 patients who did not undergo ACL reconstruction were defined as group 2. In patients with partial ACL rupture with or without ACL reconstruction, it was evaluated whether a ruptured or non- ruptured ALL was effective in this decision of conservative or surgically. The MRIs of patients with partial ACL tears were evaluated by a radiologist and it was concluded that the ALLs of 50 patients were ruptured, and 72 were intact. The ALLs of 36 patients in group 1 were ruptured, and 26 patients were intact. Fourteen patients in group 2 had ruptured ALLs, 46 patient’s ALLs were intact. Seventy-two percent of the patients with partial ACL tears who had ruptured ALLs in MRI underwent ACL reconstruction. It was found that ACL reconstruction was performed more frequently in patients with partial ACL tears with ALL rupture. Therefore, we believe that preoperative evaluations of ALLs using MRI in patients with partial ACL tears are essential for surgical planning.

Subjective assessment reported by patients shows differences between single-bundle and double-bundle anterior cruciate ligament reconstruction, systematic review and meta-analysis

To determine the functional recovery, active reincorporation, and anteroposterior and rotational stability of patients undergoing anterior cruciate ligament (ACL) reconstruction using arthroscopy techniques with simple-bundle (SB) or double-bundle (DB). The following databases were searched: PubMed, Embase (Elsevier platform), the Cochrane Central Register of Controlled Trials (Wiley platform), Web of Science, and CINAHL. Level I and II studies involving anterior cruciate ligament arthroscopy were included in the search. Records were screened by title and abstract and assessed the risk of bias of selected studies. Meta-analyses using RevMan 5.3 software were conducted on the following outcomes: knee functionality, objective measurements of knee stability, rotational knee stability and knee anterior stability, sports reincorporation, and subjective assessments. Twenty-four studies of patients undergoing ACL reconstruction were included in the qualitative and quantitative synthesis (1707 patients) for Lysholm score, Subjective International Knee Documentation Committee (IKDC) score, Tegner score, KT-1000/2000, Lachman test, Objective IKDC score, and Pivot-Shift test. A return to pre-injury level showed a significant decrease in the Lysholm score (mean difference, - 0.99; 95% CI - 1.71 to - 0.40; P = 0.007) and Tegner score (mean difference, - 0.07; 95% CI, - 0.13 to - 0.01; P = 0.02) at DB reconstruction, similar to the knee functionality outcome of the subjective IKDC score (mean difference - 1.42; 95% CI - 2.46 to - 0.38; P = 0.007). There is no clear or significant difference in clinical stability and knee function or in sports incorporation with the true difference occurring in the subjective assessment.

Independent Versus Transtibial Drilling in Anterior Cruciate Ligament Reconstruction: A Meta-analysis With Meta-regression

Background:

Anterior cruciate ligament (ACL) reconstruction can be performed with different techniques for independent and transtibial (TT) drilling of femoral tunnels, but there is still no consensus on which approach leads to the best outcome.

Purpose:

To assess whether the independent or TT drilling approach for ACL reconstruction leads to the best functional outcomes.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

A systematic literature search was conducted on July 1, 2020, using the PubMed, Web of Science, Cochrane Library, and Scopus databases. The influence of different femoral drilling techniques was analyzed through a meta-analysis in terms of patient-reported outcome measure scores, risk of complications, range of motion limitations, graft failure, and differential laxity. Subanalyses were performed to compare the different independent drilling techniques considered. Linear metaregression was performed to evaluate if the year of study publication influenced the results. The risk of bias and quality of evidence were assessed following the Cochrane guidelines.

Results:

A total of 22 randomized controlled trials including 1658 patients were included in the meta-analysis. Both International Knee Documentation Committee (IKDC) subjective score and Lysholm score were higher with the independent drilling approach (mean difference [MD], 1.24 [P = .02] and 0.55 [P = .005], respectively). No difference was documented in terms of the risk of reinjury, but independent drilling led to reduced KT-1000 arthrometer–assessed anterior tibial translation (MD, 0.23; P = .01) and a higher probability of a negative postoperative pivot-shift test finding (risk ratio, 1.13; P = .04). There were no significant differences in IKDC objective or Tegner scores. A P value of .07 was found for the association between the year of the study and IKDC objective scores.

Conclusion:

Independent femoral tunnel drilling provided better results than the TT approach, although the difference was not clinically significant. No difference was observed in the risk of reinjury. Increasingly better results were seen among surgical procedures performed in more recent years. Among the independent drilling options, the anteromedial portal technique seemed to provide the most favorable outcomes. The lack of clinically significant differences and the promising outcomes reported with new modified TT techniques suggest the importance of correct placement, rather than the tunnel drilling approach, to optimize the results of ACL reconstruction.

Clinical and Radiological Outcomes of Anteromedial Portal Versus Transtibial Technique in ACL Reconstruction: A Systematic Review

Background:

The drilling technique used to make a femoral tunnel is critically important for determining outcomes after anterior cruciate ligament (ACL) reconstruction. The 2 most common methods are the transtibial (TT) and anteromedial (AM) techniques.

Purpose:

To determine whether graft orientation and placement affect clinical outcomes by comparing clinical and radiological outcomes after single-bundle ACL reconstruction with the AM versus TT technique.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

Articles in PubMed, EMBASE, the Cochrane Library, ISI Web of Science, Scopus, and MEDLINE were searched from inception until April 25, 2020, using the following Boolean operators: transtibial OR trans-tibial AND (anteromedial OR trans-portal OR independent OR three portal OR accessory portal) AND anterior cruciate ligament.

Results:

Of 1270 studies retrieved, 39 studies involving 11,207 patients were included. Of these studies, 14 were clinical, 13 were radiological, and 12 were mixed. Results suggested that compared with the TT technique, the AM technique led to significantly improved anteroposterior and rotational knee stability, International Knee Documentation Committee (IKDC) scores, and recovery time from surgery. A higher proportion of negative Lachman (P = .0005) and pivot-shift test (P = .0001) results, lower KT-1000 arthrometer maximum manual displacement (P = .00001), higher Lysholm score (P = .001), a higher incidence of IKDC grade A/B (P = .05), and better visual analog scale score for satisfaction (P = .00001) were observed with the AM technique compared with the TT technique. The AM drilling technique demonstrated a significantly shorter tunnel length (P = .00001). Significant differences were seen between the femoral and tibial graft angles in both techniques. Low overall complication and revision rates were observed for ACL reconstruction with the AM drilling technique, similar to the TT drilling technique.

Conclusion:

In single-bundle ACL reconstruction, the AM drilling technique was superior to the TT drilling technique based on physical examination, scoring systems, and radiographic results. The AM portal technique provided a more reproducible anatomic graft placement compared with the TT technique.

Intraarticular lengths of double-bundle grafts can change during knee flexion: Intraoperative measurements in anatomic anterior cruciate ligament reconstructions

BACKGROUND

The lengths of the anteromedial bundle (AMB) and posterolateral bundle (PLB) change during knee motion in double-bundle anterior cruciate ligament (ACL) reconstruction. However, the actual intraarticular graft length would be affected by the bone tunnel position and tunnel creation angle during ACL reconstruction. The aim of this study was to investigate the intraarticular length change of the AMB and PLB in patients who underwent anatomic double-bundle ACL reconstruction.

HYPOTHESIS

We hypothesized that the PLB would show a more dynamic length change pattern than the AMB during knee flexion at ACL reconstruction.

METHODS

Thirty-two patients (16 men and 16 women) who had isolated ACL injuries with intact menisci were investigated. Anatomic double-bundle ACL reconstructions were performed using semitendinosus tendon autografts at a mean age of 30.6 years. The graft and tunnel lengths were measured intraoperatively. Intraarticular graft lengths and length changes were calculated at 0° and 90° of knee flexion during ACL reconstruction. Intraoperative data were collected prospectively, and analyses were performed retrospectively.

RESULTS

The intraarticular length of the AMB at 0° of knee flexion was 28.1±5.5mm. At 90° of knee flexion, the AMB intraarticular length decreased to 25.6±4.8mm. The intraarticular length of the PLB decreased to 17.7±4.6mm at 90° of knee flexion compared to 22.0±4.2mm at 0° of knee flexion. Changes in the intraarticular graft length during knee flexion were detected more in the PLB (4.1mm) than in the AMB (2.0mm, p=0.01).

DISCUSSION

This study demonstrated that the intraarticular length change of the PLB during knee motion was larger than that of the AMB in anatomic double-bundle ACL reconstructions with semitendinosus tendon autografts and suspensory femoral fixation devices.

LEVEL OF EVIDENCE

IV; retrospective cohort study.