Anatomic double bundle ACL reconstruction outperforms any types of single bundle ACL reconstructions in controlling dynamic rotational laxity

Femoral Tunnel Position in Anatomical Double-bundle ACL Reconstruction is not Affected by Blumensaat's Line Morphology

The aim of this study was to reveal the influence of the morphological variations of the Blumensaat's line on anteromedial (AM) and posterolateral (PL) femoral tunnel position in anatomical double-bundle anterior cruciate ligament (ACL) reconstruction.Fifty-three subjects undergoing anatomical double-bundle ACL reconstruction were included (29 female, 24 male; median age 27.4 years; range: 14-50 years). Using an inside-out transportal technique, the PL tunnel position was made on a line drawn vertically from the bottommost point of the lateral condyle at 90 degrees of knee flexion, spanning a distance of 5 to 8 mm, to the edge of the joint cartilage. AM tunnel position was made 2 mm distal to the PL tunnel position. Following Iriuchishima's classification, the morphology of the Blumensaat's line was classified into straight and hill (large and small) types. Femoral tunnel position was determined using the quadrant method. A Mann-Whitney U test was performed to compare straight and hill type knees according to AM and PL femoral tunnel position.There were 18 straight and 35 hill type knees (13 small and 22 large hill). AM and PL femoral tunnel position in straight type knees were 21.7 ± 7.0 and 33.6 ± 10.5% in the shallow-deep direction, and 42.1 ± 11.1 and 72.1 ± 8.5% in the high-low direction, respectively. In hill type knees, AM and PL femoral tunnel position were 21.3 ± 5.8 and 36.9 ± 7.1% in the shallow-deep direction, and 44.6 ± 10.7 and 72.1 ± 9.7% in the high-low direction, respectively. No significant difference in AM or PL femoral tunnel position was detected between straight and hill type knees.AM and PL femoral tunnel position in anatomical double-bundle ACL reconstruction was not affected by the morphological variations of the Blumensaat's line. Surgeons do not need to consider Blumensaat's line morphology if AM and PL femoral tunnel position is targeted at the bottommost point of the lateral condyle. This was a level of evidence III study.

Effects of higher femoral tunnels on clinical outcomes, MRI, and second-look findings in double-bundle anterior cruciate ligament reconstruction with a minimal 5-year follow-up

BACKGROUND

To perform anatomical anterior cruciate ligament reconstruction (ACLR), tunnels should be placed relatively higher in the femoral anterior cruciate ligament (ACL) footprint based on the findings of direct and indirect femoral insertion. But the clinical results of higher femoral tunnels (HFT) in double-bundle ACLR (DB-ACLR) remain unclear. The purpose was to investigate the clinical results of HFT and lower femoral tunnels (LFT) in DB-ACLR.

METHODS

From September 2014 to February 2016, 83 patients who underwent DB-ACLR and met the inclusion and exclusion criteria were divided into HFT-ACLR (group 1, n = 37) and LFT-ACLR (group 2, n = 46) according to the position of femoral tunnels. Preoperatively and at the final follow-up, clinical scores were evaluated with International Knee Documentation Committee (IKDC), Tegner activity, and Lysholm score. The stability of the knee was evaluated with KT-2000, Lachman test, and pivot-shift test. Cartilage degeneration grades of the International Cartilage Repair Society (ICRS) were evaluated on magnetic resonance imaging (MRI). Graft tension, continuity, and synovialization were evaluated by second-look arthroscopy. Return-to-sports was assessed at the final follow-up.

RESULTS

Significantly better improvement were found for KT-2000, Lachman test, and pivot-shift test postoperatively in group 1 ( P >0.05). Posterolateral bundles (PL) showed significantly better results in second-look arthroscopy regarding graft tension, continuity, and synovialization ( P <0.05), but not in anteromedial bundles in group 1. At the final follow-up, cartilage worsening was observed in groups 1 and 2, but it did not reach a stastistically significant difference ( P >0.05). No statistically significant differences were found in IKDC subjective score, Tegner activity, and Lysholm score between the two groups. Higher return-to-sports rate was found in group 1 with 86.8% (32/37) vs. 65.2% (30/46) in group 2 ( P = 0.027).

CONCLUSION

The HFT-ACLR group showed better stability results, better PL, and higher return-to-sports rate compared to the LFT-ACLR group.

ANTEROMEDIAL OR CENTRAL ANATOMIC ACL RECONSTRUCTION? A CADAVERIC HIP-TO-TOE STUDY

Objective

To compare anatomic anterior cruciate ligament (ACL) reconstruction between two tunnel positions in knees with isolated ligament tears.

Methods

Anatomic ACL reconstruction was performed, from hip-to-toe, on 15 fresh cadaveric specimens. No associated lesions were created to enhance knee instability. The protocol was conducted in three states: (1) complete isolated ACL deficiency; (2) anatomic femoral and tibial anteromedial ACL reconstruction (AM REC); and (3) anatomic femoral and tibial central ACL reconstruction (Central REC). The reconstruction protocols were randomly assigned. The continuous mechanized pivot-shift test was recorded dynamically with a tracking system.

Results

The Central REC group showed a smaller degree of internal rotation (0.6° ± 0.3° vs. 1.8° ± 0.3°, respectively, P < 0.05) and no difference in anterior translation (4.7 mm ± 0.4 mm vs. 4.5 mm ± 0.4 mm, respectively, P > 0.05) in the pivot-shift test, compared with the AM REC group.

Conclusion

The central anatomic ACL reconstruction resulted in greater restriction of internal rotation than the anteromedial anatomic ACL reconstruction. Experimental Study on Cadaver.

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'.

Arthroscopic Anterior Cruciate Ligament Repair With Single-Bundle Hamstring Tendon Augmentation Providing Complete Femoral Footprint Restoration for Sherman Type One Tears: A Technique Guide

There is renewed interest in performing arthroscopic anterior cruciate ligament (ACL) repairs in appropriate patients who have Sherman type 1 ACL tears. However, ACL repairs are associated with unacceptably high failure rates, which may be partly improved with suture augmentation. Our technique uses a hamstring autograft tendon to reconstruct a bundle through a femoral tunnel while inserting the native ACL tissue into the other bundle's femoral footprint. The tear pattern dictates whether the native ACL tissue is inserted into the anteromedial or posterolateral lateral femoral origin. The improved cellular and biomechanical milieu for healing of both the repair and reconstruction may translate to earlier return to sport and reduced failure rates. In addition, by restoring the entire femoral footprint with a single femoral tunnel, improved rotational control is achieved without the bone stock loss observed in traditional ACL double-bundle reconstruction.

Intra-Articular Biomechanical Changes of the Meniscus and Ligaments During Stance Phase of Gait Circle after Different Anterior Cruciate Ligament Reconstruction Surgical Procedures: A Finite Element Analysis

OBJECTIVE

The debate on the superiority of single- or double-bundle for anterior cruciate ligament reconstruction has not ceased. The comparative studies on intra-articular biomechanics after different surgical reconstructions are rare. This study is to evaluate the biomechanical stress distribution intra-knee after single- and double-bundle anterior cruciate ligament reconstruction by three-dimensional finite element analysis, and to observe the change of stress concentration under the condition of vertical gradient loads.

METHODS

In this study, magnetic resonance imaging data were extracted from patients and healthy controls for biomechanical analysis. Patients included in the three models were matched in age and sex. The strength and distribution of induced stresses were analyzed in two frequently used procedures, anatomical single-bundle anterior cruciate ligament reconstruction and anatomical double-bundle anterior cruciate ligament reconstruction, using femoral-graft-tibial system under different loads, to mimic a post-operation mechanical motion. The three-dimensional finite-element models for normal ligament and two surgical methods were applied. A vertical force simulating daily walking was performed on the models to assess the interfacial stresses and displacements of intra-articular tissues and ligaments. The evaluation results mainly included the stress of each part of ligament and meniscus. The stress values of different parts of three models were extracted and compared.

RESULTS

The stress of ligament/graft at femoral side of three finite-element models was significantly higher than at tibial side, while the highest level was observed in single-bundle reconstruction finite-element model. With the increase of force, the maximum stress in the medial (7.1-7.1 MPa) and lateral (4.9-7.4 MPa) meniscus of single-bundle reconstruction finite-element model shifted from the anterior horn to the central area (p = 0.0161, 0.0479, respectively). The stress was shown to be at a lower level at femoral side and posterior cruciate ligament of intra-knee in two reconstruction finite-element models than that in normal finite-element models, while presented higher level at the tibial side than normal knee (p = 0.3528). The displacement of the femoral side and intra-knee areas in reconstruction finite-element models was greater than that in normal finite-element model (p = 0.0855).

CONCLUSION

Compared with the single-bundle technique, the graft of double-bundle anterior cruciate ligament reconstruction has better stress dissipation effect and can prevent postoperative meniscus tear more effectively.

Double-Bundle Versus Single-Bundle Anterior Cruciate Ligament Reconstruction in Patients With Significant Passive Anterior Tibial Subluxation

BACKGROUND

Passive anterior tibial subluxation (PATS) is often observed in patients with anterior cruciate ligament tears. Postoperative outcomes of double-bundle (DB) and single-bundle (SB) anterior cruciate ligament reconstruction (ACLR) with significant PATS (>6 mm) are unclear.

HYPOTHESIS

DB-ACLR could achieve better stability and clinical outcomes than SB-ACLR in patients with PATS >6 mm.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Retrospective analysis was peformed on 626 consecutive patients who underwent primary anatomic ACLR between October 2016 and November 2017. Anterior subluxation of the lateral and medial compartments in extension relative to the femoral condyles was measured on preoperative magnetic resonance imaging scans. Among patients who demonstrated significant PATS (>6 mm) in the lateral compartment, 54 who underwent DB-ACLR (study group) were matched to 54 who underwent SB-ACLR (control group). PATS, stability (pivot-shift test and KT-2000 arthrometer), the Lysholm score, and the International Knee Documentation Committee (IKDC) grade were investigated preoperatively and at 3- to 4-year follow-up.

RESULTS

The preoperative mean PATS values in the lateral and medial compartments were not significantly different between groups (control vs study: lateral compartment, 8.1 ± 1.8 vs 8.5 ± 2.1 mm; medial compartment, 5.2 ± 1.9 vs 5.4 ± 1.9 mm; P > .05). Postoperatively, mean PATS values in the lateral and medial compartments of the study group were significantly improved as compared with the control group (control vs study: lateral compartment, 5.9 ± 2.8 vs 3.2 ± 4.1 mm; medial compartment, 3.7 ± 2.9 vs 1.4 ± 2.3 mm; P < .05). Significantly superior results were found for knee stability in the study group regarding the Lachman test (grade 0/1/2/3, study vs control: 29/22/3/0 vs 16/28/10/0; P = .031), pivot-shift test (grade 0/1/2/3, study vs control: 44/9/1/0 vs 30/19/5/0; P = .023), and KT-2000 arthrometer (study vs control: 2.5 ± 1.5 vs 3.9 ± 1.4 mm; P < .001). Clinical scores showed significantly better results in the study group in terms of IKDC score (study vs control: 87.9 ± 8.7 vs 81.2 ± 15.0; P = .01), Tegner activity score (study vs control: 6.0 ± 1.4 vs 4.9 ± 1.5; P < .001), and Lysholm score (study vs control: 91.7 ± 7.0 vs 86.3 ± 11.4; P = .004).

CONCLUSION

DB-ACLR achieved better knee stability and clinical outcomes when compared with SB-ACLR in patients with PATS >6 mm at 3- to 4-year follow-up.

Anteromedial Tibial Attachment in Single-Bundle Anterior Cruciate Ligament Reconstruction Can Represent Normal Kinematics in Computer Simulation

Tunnel position during anterior cruciate ligament (ACL) reconstruction is considered as an important factor to restore normal knee kinematics and to gain better clinical outcomes. It is still unknown where the optimal femoral and tibial tunnel position is located in single-bundle (SB) ACL reconstruction. The purposes of this study were to analyze the knee kinematics with various graft positions and to propose the optimal graft position during SB ACL reconstruction. A musculoskeletal computer simulation was used to analyze knee kinematics. Four attachments on the femoral side (anteromedial [AM], mid, posterolateral [PL], and over-the-top positions) and three attachments on the tibial side (AM, middle, and PL positions) were determined. The middle-bundle attachment was placed at the midpoint of the AM and PL bundle attachments for the femoral and tibial attachments. SB ACL reconstruction models were constructed to combine each of the four femoral attachments with each of three tibial attachments. Kinematic comparison was made among a double-bundle (DB) model and 12 SB reconstruction models during deep knee bend and stair descent activity. The tunnel position of the tibia had greater effect of knee kinematics than that of the femur. AM tibial attachment models showed similar medial and lateral anteroposterior positions to the DB model for both activities. Axial rotation in the AM tibial attachment models was similar to the DB model regardless of the femoral attachment, whereas greater maximum axial rotation was exhibited in the PL tibial attachment models, especially during stair descent activity. AM tibial attachment can represent normal knee kinematics, whereas the PL tibial attachment can induce residual rotational instability during high-demand activities. The AM tibial tunnel is recommended for SB ACL reconstruction.

Superior results of return to sport after double-bundle versus single-bundle anterior cruciate ligament reconstruction in young active patients

PURPOSE

To compare return to sport and clinical results in young active patients who underwent anatomic single-bundle (SB) versus double-bundle (DB) anterior cruciate ligament reconstruction (ACLR).

METHODS

Young active patients undergoing SB or DB ACLR from 2017 to 2019 at our institution were retrospectively reviewed. The primary outcome measures were the rate and time to return to sports, with secondary measures including the Lachman test, pivot shift test, Lysholm scores, International Knee Documentation Committee (IKDC) scores and graft rupture.

RESULTS

The study included a total of 90 patients (DB group, 42; SB group, 48), with a mean follow-up of 27.1 ± 6.1 months. Young active patients who underwent DB ACLR had a higher rate of return to pivoting sports than those who underwent SB ACLR (HR = 2.4; 95% confidence interval [CI]: 1.4, 4.1; p = 0.013). The DB group returned to pivoting sports at a mean ± SD of 11.0 ± 2.9 months compared with 12.7 ± 2.7 months in the SB group (p = 0.01). There was one traumatic failure in the SB group and one contralateral ACL rupture in the DB group. There was no significant difference in the rate and time to return to running, Lachman test, pivot-shift test, Lysholm or IKDC scores in either group.

CONCLUSION

Both anatomical SB and DB techniques achieved satisfactory clinical outcomes. DB techniques led to superior performance of return to pivoting sports but nonsignificant differences in time and rate of return to running, passive stability measurement, subjective knee function outcome and graft rupture rate in both groups at the 2-year follow-up. The DB ACLR should be considered a viable option to treat young patients with high activity demands.

LEVEL OF EVIDENCE

III.

The radiographic tibial spine area is correlated with the occurrence of ACL injury

PURPOSE

The purpose of this study was to reveal the possible influence of the tibial spine area on the occurrence of ACL injury.

METHODS

Thirty-nine subjects undergoing anatomical ACL reconstruction (30 female, 9 male: average age 29 ± 15.2) and 37 subjects with intact ACL (21 female, 16 male: average age 29 ± 12.5) were included in this study. In the anterior-posterior (A-P) and lateral knee radiograph, the tibial spine area was measured using a PACS system. In axial knee MRI exhibiting the longest femoral epicondylar length, the intercondylar notch area was measured. Tibial spine area, tibial spine area/body height, and tibial spine area/notch area were compared between the ACL tear and intact groups.

RESULTS

The A-P tibial spine area of the ACL tear and intact groups was 178 ± 34 and 220.7 ± 58mm², respectively. The lateral tibial spine area of the ACL tear and intact groups was 145.7 ± 36.9 and 178.9 ± 41.7mm², respectively. The tibial spine area was significantly larger in the ACL intact group when compared with the ACL tear group (A-P: p = 0.02, lateral: p = 0.03). This trend was unchanged even when the tibial spine area was normalized by body height (A-P: p = 0.01, lateral: p = 0.02). The tibial spine area/notch area of the ACL tear and intact groups showed no significant difference.

CONCLUSION

The A-P and lateral tibial spine area was significantly smaller in the ACL tear group when compared with the ACL intact group. Although the sample size was limited, a small tibial spine might be a cause of knee instability, which may result in ACL injury.

LEVEL OF EVIDENCE

Level III.

An Analysis of the Femoral Drilling Angle to Avoid Tunnel Collision during Double-Bundle Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction on the Knee

Concomitant anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction has been reported as an effective technique for providing rotational control of the knee. However, the intraoperative risk of collision with an ACL tunnel during the drilling for the femoral ALL tunnel has been described. The purpose of this study was to investigate the various femoral drilling procedures to avoid tunnel collisions during combined double-bundle ACL and ALL reconstruction. Nine cadaveric knees were used in this study. ACL drilling was performed through the anteromedial portal to footprints of the posterolateral bundle at 120° (PL120) and 135° (PL135) knee flexion and the anteromedial bundle at 120° (AM120) and 135° (AM135) knee flexion. ALL drilling was performed at 0° (Cor0-ALL) and 30° (Cor30-ALL) coronal angles using a Kirschner wire (K-wire). The distance between the ALL footprint and ACL K-wire outlets, axial angles of ALL K-wires colliding with ACL K-wires, and distances from the ALL footprint to the collision point were measured. From these values, the safe zone, defined as the range of axial angles in which no collisions or penetrations occurred, was identified by simulation of tunnels utilized for reconstruction grafts in each drilling procedure. The point-to-point distance from the ALL footprint to the K-wire outlet was significantly greater in the AM120 than the AM135 (13.5 ± 3.1, 10.8 ± 3.2 mm; p = 0.048) and in the PL135 than the PL120 (18.3 ± 5.5, 16.1 ± 6.5 mm; p = 0.005) conditions, respectively. During an ACL drilling combination of PL135/AM120, a safe zone of > 45° in Cor30-ALL was identified. With a narrow safe zone during the PL135/AM120 combination only, the risk of femoral tunnel collisions in combined double-bundle ACL and ALL reconstruction is high. AM drilling at 120° and PL drilling at > 135° knee flexion, combined with ALL drilling at 30° coronal angle and > 45° axial angle, may reduce this risk.

Anatomical Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autografts: A Comparative Study of Three Different Techniques

The ideal procedure for anterior cruciate ligament (ACL) reconstruction is one that can achieve anatomical restoration for a better ACL function. This retrospective comparative study was conducted to evaluate the objective and subjective clinical results of the conventional single-bundle femoral round (SBR) tunnel technique, the single-bundle femoral oval (SBO) tunnel technique, and the double-bundle (DB) surgical technique for anatomical ACL reconstruction with hamstring tendon autografts. Patients who underwent the SBO, SBR, and DB ACL reconstructions from January 2016 to August 2017 were included in this study. A total of 163 patients underwent different surgical techniques; 41 patients underwent the SBO procedure, 78 patients received SBR, and the remaining 44 patients underwent the DB procedure. The Lachman's test, pivot-shift test, Lysholm's score, International Knee Documentation Committee (IKDC) score, and Tegner's score were compared among groups postoperatively. KT-1000 was used to measure the anterior laxity of the knee. Magnetic resonance imaging was used to compare the ACL graft maturity. Second-look arthroscopy was conducted to compare the graft status and synovial coverage. Significant differences among groups were found with respect to the Lysholm's score, Tegner's score, and IKDC score. Patients in the SBO and DB groups acquired higher functional scores than the SBR group. More patients with positive pivot-shift test were observed in the SBR group than other groups at 12- and 24-month postoperative follow-ups. The postoperative KT-1000 was better in the SBO and DB groups than in the SBR group. The mean signal/noise quotient (SNQ) of the SBO group was 2.70 ± 0.92, significantly lower than 3.58 ± 1.21 of the SBR group. Despite a higher proportion of patients with grade B or C synovial coverage and partial graft injury found in the SBR group, there were no significant differences among the groups. The SBO and DB technique achieved better clinical results than the SBR technique. The SBO technique was indeed an ideal surgical procedure for ACL reconstruction provided that the shortcoming of DB technique must be taken into account. This is a Level III, retrospective comparative study.

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.

Anterolateral ligament reconstruction in addition to primary double-bundle anterior cruciate ligament reconstruction for grade 3 pivot shift improves residual knee instability during surgery

Purpose

High-grade pivot shift in the anterior cruciate ligament (ACL) injured knee is a risk factor for postoperative residual pivot shift. Procedures in addition to ACL reconstruction such as anterolateral ligament (ALL) reconstruction have been performed for patients with a high-risk of residual pivot shift. The aim of this study was to investigate the effect of the addition of ALL reconstruction to primary double-bundle ACL reconstruction in patients with preoperative high-grade pivot shift to improve stability as evaluated by quantitative measurement.

Methods

Patients with ACL injuries who showed preoperative grade 3 subjective pivot shift and who underwent primary double-bundle ACL reconstruction combined with ALL reconstructions were retrospectively enrolled. Anterior tibial translation (ATT) in the Lachman test, and acceleration and external rotational angular velocity (ERAV) in the pivot shift were measured as quantitative values. Quantitative values before surgical intervention for ACL-injured knees (ACLD) and uninjured contralateral knees (intact), after temporary fixation of the isolated ACL grafts (ACLR), and subsequently after temporary fixation of both ACL and ALL grafts (ACLR + ALLR) were measured with the patient under general anaesthesia.

Results

In total, 18 patients were included. The ATT was lower in ACLR and ACLR + ALLR than in intact (P = .008 and .005), while there was no significant difference between ACLR and ACLR + ALLR (P > .05). The acceleration of ACLR + ALLR was lower than that for ACLR (P = .008), while there was no significant difference between intact and ACLR or ACLR + ALLR (P > .05). The ERAV of ACLR was higher than that of intact (P < .001), while that of ACLR + ALLR was lower than that of ACLR (P < 0.001), and there was no significant difference in ERAV between intact and ACLR + ALLR (P > 0.05).

Conclusion

According to quantitative assessment of the pivot shift, the addition of ALL reconstruction to primary double-bundle ACL reconstruction improved residual knee instability and restored knee stability during surgery. Combination of ALL reconstruction with primary double-bundle ACL reconstruction was effective for patients with ACL injuries exhibiting a preoperative grade 3 subjective pivot shift.

Level of evidence

IV

Anatomic single- and double-bundle ACL reconstruction both restore dynamic knee function: a randomized clinical trial-part II: knee kinematics

PURPOSE

Compare side-to-side differences for knee kinematics between anatomic single-bundle (SB) and anatomic double-bundle (DB) ACLR during downhill running at 6 and 24 months post ACLR using high-accuracy dynamic stereo X-ray imaging. It was hypothesized that anatomic DB ACLR would better restore tibio-femoral kinematics compared to SB ACLR, based on comparison to the contralateral, uninjured knee.

METHODS

Active individuals between 14 and 50 years of age that presented within 12 months of injury were eligible to participate. Individuals with prior injury or surgery of either knee, greater than a grade 1 concomitant knee ligament injury, or ACL insertion sites less than 14 mm or greater than 18 mm were excluded. Subjects were randomized to undergo SB or DB ACLR with a 10 mm-wide quadriceps tendon autograft harvested with a patellar bone block and were followed for 24 months. Dynamic knee function was assessed during treadmill downhill running using a dynamic stereo X-ray tracking system at 6 and 24 months after surgery. Three-dimensional tibio-femoral kinematics were calculated and compared between limbs (ACLR and uninjured contralateral) at each time point.

RESULTS

Fifty-seven subjects were randomized (29 DB) and 2-year follow-up was attained from 51 (89.5%). No significant differences were found between SB and DB anatomic ACLR for any of the primary kinematic variables.

CONCLUSIONS

Contrary to the study hypothesis, double-bundle reconstruction did not show superior kinematic outcomes compared to the single-bundle ACLR. While neither procedure fully restored normal knee kinematics, both anatomic reconstructions were similarly effective for restoring near-normal dynamic knee function. The findings of this study indicate both SB and DB techniques can be used for patients with average size ACL insertion sites.

LEVEL OF EVIDENCE

Level I.

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

PURPOSE

To compare the clinical, second-look arthroscopic, magnetic resonance imaging (MRI), and dynamic-contrast-enhanced MRI (DCE-MRI) findings between remnant-tensioning single-bundle (RT-SB) and double-bundle (DB) anterior cruciate ligament reconstruction (ACLR).

METHODS

Sixty-seven patients with acute or subacute anterior cruciate ligament (ACL) injury were randomized to undergo RT-SB or DB ACLR. Twenty-six patients in the RT-SB group and 28 in the DB group were evaluated using stability tests (Lachman test, pivot-shift test, and KT-2000 arthrometer) and multiple clinical scores. One year postoperatively, all 54 patients underwent MRI for evaluation of graft continuity and graft signal/noise quotient and DCE-MRI for the calculation of normalized area under the curve (nAUC) as a marker of graft vascularity. Among them, 41 patients underwent second-look arthroscopy for the evaluation of graft continuity, graft tension, and synovialization. The results were compared between the 2 groups.

RESULTS

At the minimum 2-year follow-up (28.7 ± 6.4 months), the stability tests, clinical scores, second-look arthroscopic findings, and MRI findings were not significantly different between the groups. However, the mean nAUC values on DCE-MRI for the ACL graft were significantly higher in the RT-SB group than those in the DB group in all 3 zones (nAUC_proximal, P = .005; nAUC_middle, P = .021; nAUC_distal, P = .027; and nAUC_average, P = .008).

CONCLUSION

For acute or subacute ACL injury, the RT-SB ACLR showed an outcome comparable to that of DB ACLR in terms of knee stability, clinical scores, MRI findings, and second-look arthroscopic findings. Moreover, RT-SB ACLR showed better graft vascularity 1 year postoperatively than DB ACLR using DCE-MRI.

LEVEL OF EVIDENCE

II, prospective randomized controlled trial.

Biomechanical comparison of single-bundle versus double-bundle anterior cruciate ligament reconstruction: a meta-analysis

BACKGROUND

Of the many issues regarding surgical techniques related to anterior cruciate ligament reconstruction (ACLR), single-bundle (SB) or double-bundle (DB) ACLR is one of the most debated topics. However, it is unclear which of the techniques yields better outcomes after ACLR for ACL injury. The purpose of this meta-analysis was to compare the benefits of SB versus DB ACLR in terms of biomechanical outcomes.

METHODS

The electronic databases MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and Scopus were searched for relevant articles comparing the outcomes of SB-ACLR versus DB-ACLR that were published until November 2019.

RESULTS

Seventeen biomechanical studies were included. The anterior laxity measured using the anterior drawer test showed significantly better results in DB-ACLR when compared with SB-ACLR. In addition, outcomes of the anterior tibial translation test under a simulated pivot shift presented with better results at low flexion and 30° in DB-ACLR, compared with SB-ACLR. However, there were no significant biomechanical differences between the groups in internal rotation.

CONCLUSIONS

The present study demonstrated that both techniques for ACLR are associated with restoration of normal knee kinematics. DB-ACLR is superior to SB-ACLR in terms of restoration of anteroposterior stability. However, which technique yields better improvement in internal rotation laxity, and internal rotation laxity under a simulated pivot shift at a specific angle, remains unclear.

LEVEL OF EVIDENCE

This is a level II meta-analysis.

Revision Anterior Cruciate Ligament Reconstruction After Primary Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: A Case Series of 40 Patients

PURPOSE

To evaluate the surgical methods according to the status of tunnels at the time of revision anterior cruciate ligament reconstruction (ACLR) and to evaluate clinical outcomes of revision ACLR in patients who underwent primary ACLR with the anatomic 4-tunnel double-bundle (DB) technique.

METHODS

A total of 487 patients who underwent primary anatomic DB ACLR from April 2010 to July 2016 were retrospectively reviewed, and among those knees, the patients who underwent revision ACLR were included in the study. The patients with concomitant posterior cruciate ligament injuries were excluded. Forty patients (40 knees) were identified and enrolled. The surgical methods were reviewed. The range of motion, objective laxity using KT-2000, Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, and Tegner score after revision ACLR were compared with those after primary ACLR in the same patient using paired t-test with Bonferroni correction.

RESULTS

The timing of reinjury after primary ACLR and mean interval between primary and revision ACLR were 18 months (range 1.5-80 months) and 24 months (range 4-82 months), respectively. Among 40 patients, 38 patients (95%) underwent 1-stage revision with the DB technique using pre-existing tunnels without compromised positioning of the grafts, and the other 2 patients (5%) underwent 2-stage revision. The postrevision range of motion, KT-2000, Lysholm score, Hospital for Special Surgery score, International Knee Documentation Committee subjective score, and Tegner score were 137 ± 7°, 2.4 ± 1.2 mm, 91.4 ± 5.8, 98.9 ± 2.2, 78.6 ± 11.5, and 5.5 ± 1.2, respectively, and did not show any differences from those after primary ACLR.

CONCLUSIONS

In the revision setting after primary anatomic DB ACLR, most of the cases could be managed with 1-stage revision with DB technique using pre-existing tunnels, and the objective laxity and clinical scores after revision DB ACLR were comparable with those after primary DB ACLR.

LEVEL OF EVIDENCE

Case series, Level IV.

The Push-Through Sign-Making the Decision for Selective-Bundle Anterior Cruciate Ligament Surgery

Partial anterior cruciate ligament (ACL) tears are often difficult to diagnose and treat. Recent interest in the literature has focused on performing selective-bundle ACL reconstruction in patients with symptomatic partial ACL tears when one of the ACL bundles is intact. However, the clinical examination, magnetic resonance imaging, and arthroscopic evaluation of partial ACL tears may not correlate, and proper assessment of the integrity of the intact portion of the ACL continues to be a challenge. If a selective-bundle ACL reconstruction is performed in a patient with an apparently intact but structurally damaged individual bundle, the outcome would be compromised by leaving the damaged bundle in place. This technical note provides a description of a simple and reliable arthroscopic method to aid in the diagnosis of a partial ACL tear. The use of this method to assess remaining ligamentous tissue will assist surgeons in deciding for or against selective-bundle ACL reconstruction.

[Research progress of double-bundle anterior cruciate ligament reconstruction in adolescents]

OBJECTIVE

To review the advances in double-bundle anterior cruciate ligament (ACL) reconstruction in adolescents at home and abroad.

METHODS

Recent literature about double-bundle ACL reconstruction in adolescents at home and abroad was extensively consulted, and the relationship between bone canal and epiphyseal plate, clinical verification of surgical safety, and clinical effectiveness of double-bundle ACL reconstruction in adolescents were summarized and analyzed.

RESULTS

Double-bundle ACL reconstruction has certain advantages in clinical stability and re-rupture rate when compared with single-bundle ACL reconstruction in adolescents, and there is no significant difference in safety between them.

CONCLUSION

Double-bundle ACL reconstruction in adolescents can achieve lower re-rupture rate and better stability when compared with single-bundle reconstruction. However, the sample size of clinical research is too small, and the follow-up time is too short, so the effectiveness needs to be continuously observed.

Knee hyperextension and a small lateral condyle are associated with greater quantified antero-lateral rotatory instability in the patients with a complete anterior cruciate ligament (ACL) rupture

PURPOSE

To identify factors associated with quantified rotatory stability (pivot-shift phenomenon) in the anterior cruciate ligament (ACL)-injured knee joint.

METHODS

A consecutive sample of 54 patients who were diagnosed with an ACL injury and admitted to our hospital to undergo ACL reconstruction were enrolled in this study. Antero-lateral rotatory laxity of the knee joint was quantified using a Kinematic Rapid Assessment device (KiRA; Orthokey LTD) under spinal block before initiating reconstruction of the ACL. Univariate and multivariate regressions were performed assuming relationships between patient characteristics (independent variables) and quantified antero-lateral rotatory stability (a dependent variable).

RESULTS

It was observed that a low BMI (t = - 1.659, n.s.), greater passive knee extension angle (t = 2.374, P = 0.023), and a narrower lateral femoral condyle width index (t = - 1.712, n.s.) could be candidates associated with the antero-lateral rotatory instability, using univariate analysis. Employing multivariate analysis controlling for these three variables, that the range of passive knee extension was found to be significantly associated with antero-lateral rotatory instability in the ACL-injured knee joint (t = 2.21, P = 0.035). Patients were then divided into two groups (pivot-shift negative versus positive groups) based on the KiRA-documented quantified pivot-shift test. Interestingly, 23.3% of patients were pivot-shift negative, even though their ACL was confirmed as a complete rupture by arthroscopic observations. The degree of passive knee extension was 2.3 ± 4.5 (mean ± SD) in the pivot-shift negative group, while it was 6.8 ± 6.6 in the pivot-shift positive group (n.s.). The lateral femoral condyle width index was 36.6 ± 2.0% in the pivot-shift negative group, and it was significantly wider than in the pivot-shift positive group (33.8 ± 2.6%, P = 0.0046). Finally, we estimated that the risk of positive pivot-shift depends on the degree of knee extension. The logistic regression analysis revealed that genu recurvatum significantly increased the odds ratio for positive pivot-shift (OR = 3.08, P = 0.047, 95% CI = 1.017-9.350).

CONCLUSIONS

This study revealed that greater antero-lateral rotatory instability in patients with a complete ACL rupture was associated with genu recurvatum and small lateral femoral condyle. These factors should be considered as predictors of a poor outcome from an ACL reconstruction due to a higher load on the ACL graft, and therefore, the attending physicians should modify the treatment strategies accordingly. This study indicates that joint hyperlaxity and bone morphology contribute to the rotational stability of the knee joint, in addition to the ACL and antero-lateral complex (ALC).

LEVEL OF EVIDENCE

IV.