Graft Size and Orientation Within the Femoral Notch Affect Graft Healing at 1 Year After Anterior Cruciate Ligament Reconstruction

Sagittal Inclination Angle of the Graft Affects Graft Maturity and Knee Stability After Anterior Cruciate Ligament Reconstruction

OBJECTIVE

The influence of the graft sagittal inclination angle (SIA) on knee stability, biomechanics, and graft maturity has been elucidated. However, no study has comprehensively described the effects of SIA on the aforementioned postoperative prognostic indicators. So, we aimed to determine whether the sagittal inclination angle (SIA) of a graft is associated with postoperative graft maturity, joint stability, and joint function after anterior cruciate ligament (ACL) reconstruction.

METHODS

Patients who had undergone ACL reconstruction between April 2019 and February 2022 and those with intact ACL were eligible. Using magnetic resonance imaging, graft maturity was evaluated as the mean signal-to-noise quotient (SNQ) measured in three regions. Anterior tibial translation (ATT) was used to evaluate knee stability. Correlation analysis was conducted for the SIA, ATT, and clinical outcome scores. Multivariate stepwise regression analysis was used on the SIA and potential risk factors to determine their association with the graft SNQ. The SIA threshold of knee instability was calculated by receiver-operating characteristic curves.

RESULTS

Sixty-three postoperative patients were enrolled. The SIA was significantly negatively associated with graft SNQ value. A multivariate stepwise regression analysis showed that SIA and body mass index were significant influencing factors associated with the graft SNQ. Correlations between the SIA and medial and lateral ATT were statistically significant. A larger SIA resulted in a decreased probability of medial and lateral ATT ≥ 5 mm. The SIA threshold of an increased risk of lateral ATT ≥ 5 mm was < 44.4°. A positive correlation was observed between SIA and subjective symptom subscales in the KOOS.

CONCLUSIONS

A low SIA is not conducive to graft maturation after ACL reconstruction. A larger graft SIA was correlated with better postoperative knee stability. However, the effect of the SIA on joint function was only significant in terms of symptoms. Therefore, these new findings provide new ideas for preoperative assessment and intraoperative determination of the ideal graft inclination.

Lateral extra-articular tenodesis does not enhance ACL graft healing, however, does reduce graft tunnel widening

PURPOSE

The study hypothesized that the addition of lateral extra-articular tenodesis (LEAT) in anterior cruciate ligament reconstruction (ACLR) had a significant effect on ACL graft healing.

METHODS

A total of 80 patients were divided into two cohorts matched for gender, age, body mass index, time from surgery to post-operative MRI and graft diameter. Forty patients underwent ACL reconstruction alone, while 40 underwent ACLR in addition to LEAT. Patients underwent a magnetic resonance imaging scan at 12 months post-surgery; tunnel apertures were measured using multiplanar reformation, graft healing was assessed using signal-to-noise quotient (SNQ) in three regions of interest and finally graft maturity and integration were classified using the Howell and Ge scale, respectively. In addition, clinical evaluation and patient-reported outcome measures were collected.

RESULTS

The mean femoral tunnel widening at 12 months post-surgery was 39.8 ± 14.0% in the ACLR + LEAT group and 55.2 ± 12.7% in the ACLR alone group (p < 0.05). The mean tibial tunnel widening was 29.3 ± 12.7% in the ACLR + LEAT group and 44.4 ± 12.1% in the ACLR group (p < 0.05). The mean adjusted graft SNQ was 9.0 ± 14.9 in the ACLR + LEAT group and 9.5 ± 11.4 in the ACLR group (n.s.).

CONCLUSION

At 1 year post-operatively, we noted significantly less femoral and tibial tunnel widening in the ACLR + LEAT group. LEAT did not result in a statistically significant effect on graft healing.

LEVEL OF EVIDENCE

Level III.

Which technique provides more benefits in return to sports and clinical outcomes after anterior cruciate ligament reconstruction: Double-bundle or single-bundle? A randomized controlled study

BACKGROUND

The achievement of an optimal return to sport (RTS) has remained a key goal after sports-related injuries, with the ongoing debate on the effectiveness of different surgical approaches for anterior cruciate ligament (ACL) rupture. This study aims to assess clinical outcomes and RTS across various surgical methods, such as anatomical single-bundle reconstruction (ASBR), central-axial single-bundle reconstruction (CASBR), and double-bundle reconstruction (DBR).

METHODS

A randomized clinical trial was conducted, comprising 191 patients who underwent ACL rupture. These patients were divided into three groups based on the ACL reconstruction techniques they received (ASBR, CASBR, DBR). Over the 2-year follow-up period, the study assessed RTS through four single-hop tests, isokinetic extension tests, and limb asymmetry indices. Postoperative graft status was determined using the signal-to-noise quotient (SNQ), while knee function was evaluated using the International Knee Documentation Committee 2000 (IKDC-2000) score, Lysholm score, Tegner score, and degree of knee laxity. A binary logistic regression model was developed to forecast the factors influencing ideal RTS.

RESULTS

DBR (67.63%) and CASBR (58.00%) exhibited higher RTS passing rates compared to ASBR (30.39%; χ2 = 19.57, P <0.05). Quadriceps strength symmetry in the lower limbs was identified as the key determinant of RTS (χ2 = 17.08, P <0.05). The RTS rate was influenced by SNQs of the graft's tibial site (odds ratio: 0.544) and quadriceps strength of the reconstructed knee joint at 60°/s (odds ratio: 6.346). Notably, the DBR group showed enhanced knee stability, evidenced by superior results in the Lachman test (χ2 = 13.49, P <0.01), objective IKDC-2000 (χ2 = 27.02, P = 0.002), and anterior instability test (χ2 = 9.46, P <0.01). Furthermore, DBR demonstrated superior clinical outcomes based on the Lysholm score (DBR: 89.57 ± 7.72, CASBR: 83.00 ± 12.71, ASBR: 83.21 ± 11.95; F = 10.452, P <0.01) and IKDC-2000 score (DBR: 90.95 ± 7.00, CASBR: 84.64 ± 12.68, ASBR: 83.63 ± 11.41; F = 11.78, P <0.01).

CONCLUSION

For patients with ACL rupture, more ideal RTS rate and clinical outcomes were shown in the DBR group than in the ASBR and CASBR groups. Autograft status and quadriceps strength are postively related to RTS.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05400460).

Body Mass Index Between 15 and 30 Does Not Influence Patient-Reported Outcomes After Anterior Cruciate Ligament Surgery Using a 10-mm-Diameter Bone-Tendon-Bone Graft

Purpose

To investigate the relation between body mass index (BMI) and outcomes after anterior cruciate ligament reconstruction (ACLR) using 10-mm-diameter bone-patellar tendon-bone grafts.

Methods

In this retrospective study, the Surgical Outcome System was used to measure patient-reported outcomes before and after ACLR between 2015 and 2019. The inclusion criteria consisted on patients undergoing primary ACLR performed by the senior surgeon, with recorded age of 15 years or older and BMI of 15.0 to 30. The exclusion criteria included revisions, concomitant procedures, age younger than 15 years, and unknown BMI. Patients were divided into cohorts to evaluate the Marx Activity Rating Scale (MARS), Tegner, International Knee Documentation Committee (IKDC), and Lysholm scores at various time points from injury to 2 years postoperatively.

Results

A total of 137 patients (100 male and 37 female patients) with an average age of 33 years (95% confidence interval, 30.6-35.4 years) and average BMI of 23.58 (95% confidence interval, 23.1-24.0) were divided into those with a BMI of 15 to 23.4 (group A, n = 69) and those with a BMI of 23.5 to 30 (group B, n = 68). A significant difference in MARS scores was found between the BMI groups before treatment, with mean scores of 11.55 (group A) and 9.41 (group B) (P = .011), and Tegner scores showed significance at 2 years, with scores of 6.45 and 5.41 for groups A and B, respectively (P = .009). Daily function scores were all insignificant. Female patients exhibited no significant differences across any patient-reported outcome measures or time points. Contrarily, male patients showed a significant difference in pretreatment MARS scores (14.30 in group A vs 9.96 in group B, P = .011). Additionally, scores at 2 years depicted Tegner values of 7.40 in group A versus 5.30 in group B (P = .012) and IKDC values of 96.92 in group A versus 90.47 in group B (P = .048). All results for female and male patients aged 30 years or younger indicated no significance.

Conclusions

Regardless of patient age or sex, BMI is not significantly associated with patient-reported outcomes after ACLR using 10-mm-diameter bone-patellar tendon-bone grafts.

Level of Evidence

Level III, retrospective cohort study.

Evaluation of Graft Maturation by MRI in Anterior Cruciate Ligament Reconstruction With and Without Concomitant Anterolateral Ligament Reconstruction

Background

Single-bundle anterior cruciate ligament reconstruction (SB-ACLR) with concomitant anterolateral ligament reconstruction (ALLR) has been associated with better clinical results when compared with isolated SB-ACLR. However, it is not known whether the improved outcomes are the result of the influence of concomitant ALLR on ACL graft healing.

Purpose/Hypothesis

The purpose of this study was to determine whether concomitant ALLR is associated with improved graft ligamentization after SB-ACLR. It was hypothesized that ALLR would not affect graft healing.

Study Design

Cohort study; Level of evidence, 3.

Methods

A 1 to 1 matching study was conducted on a consecutive series of 732 patients who underwent ACLR using a hamstring tendon autograft between 2007 and 2019. Patients were excluded if they had skeletal immaturity, inflammatory joint disease, multiple ligament reconstruction (other than ALLR), or a graft rupture. Patients with concomitant SB-ACLR and ALLR (SB-ACLR/ALLR) and isolated SB-ACLR were matched 1 to 1 based on age, sex, examination under anesthesia (EUA) grade 3 pivot shift, EUA grade 3 anterior drawer test, presence of graft impingement, sagittal graft angle, skeletal maturity, lack of generalized ligamentous laxity, and multiple ligamentous injury. A total of 40 matched pairs underwent postoperative magnetic resonance imaging (MRI) within the second year after surgery to assess graft ligamentization, which was measured by the signal-to-noise quotient (SNQ) of the ACL graft.

Results

The mean follow-up period was 41 months, with a 2-year follow-up rate of 80% in the SB-ACLR/ALLR group and 98% in the isolated SB-ACLR group. The mean duration between the index operation and MRI was 16.4 ± 3.4 months. No significant difference was observed in the SNQ of the ACL graft between the SB-ACLR/ALLR and SB-ACLR groups (6.9 ± 4.6 vs 5.2 ± 4.8, respectively; P = .066).

Conclusion

Study findings indicated that a concomitant ALLR at the time of hamstring tendon autograft ACLR did not affect graft healing as assessed by the SNQ of the ACL graft.

Anterior cruciate ligament repair versus reconstruction: A clinical, MRI and patient-reported outcome comparison

BACKGROUND

There has been a resurgence in anterior cruciate ligament (ACL) repair for proximal tears using modern surgical techniques and technology. This study aims to compare ACL repair with reconstruction using MRI, clinician-measured and patient-reported outcome measures (PROMs).

METHODS

A post-hoc analysis was performed on prospectively collected data from 20 consecutive primary ACL repairs by the senior author. This was compared with an age and sex-matched cohort of 20 ACL reconstructions by the same surgeon using PROMs, return-to-sport (RTS) testing, and MRI signal noise quotient (SNQ).

RESULTS

Repairs demonstrated equivalent post-operative PROMs to reconstructions as measured by International Knee Documentation Committee subjective score (78.5 ± 17.1 vs. 83.7 ± 13.3, P = 0.333), Tegner Activity Scale (5.9 ± 1.8 vs. 6.1 ± 2.6, P = 0.646) and Lysholm score (89.8 ± 10.0 vs. 89.6 ± 10.4, P = 0.762). There was no difference in repairs and reconstructions passing quadriceps strength criteria (50% vs. 53%, P = 0.097). A greater proportion of repairs passed hamstrings strength criteria (86% vs. 60%, P = 0.023) and hamstrings-to-quadriceps ratio (71% vs. 20%, P = 0.003). There were no differences across hop and Y-balance testing. Repairs had earlier RTS assessment (8.2 ± 2.8 months vs. 10.6 ± 1.4 months, P = 0.020). On 12-month MRI, repairs demonstrated higher femoral (8.8 ± 5.7 vs. 4.6 ± 2.9, P = 0.009) and tibial SNQ (10.0 ± 5.7 vs. 4.3 ± 4.2, P = 0.001), with no mid-substance difference (12.3 ± 8.5 vs. 7.6 ± 5.2, P = 0.074). There were no graft failures.

CONCLUSIONS

When patient selection is optimized for proximal tears, ACL repairs demonstrate equivalent PROMs and better objective outcomes to reconstructions at an earlier timepoint. Repair tissue quality on MRI shows higher signal at tibial and femoral attachments.

Comparison of Primary Repair of the Anterior Cruciate Ligament and Anterolateral Structures to Reconstruction and Lateral Extra-articular Tenodesis at 2-Year Follow-up

BACKGROUND

Lateral extra-articular procedures have been effective in reducing graft rupture rates after anterior cruciate ligament (ACL) reconstruction (ACLR), but the evidence supporting their role in ACL repair is sparse.

PURPOSE/HYPOTHESIS

The purpose was to compare clinical and radiological outcomes of ACLR and lateral extra-articular tenodesis (LET) (ACLR+LET) against combined repair of the ACL and anterolateral (AL) structures (ACL+AL Repair). It was hypothesized that patients undergoing ACL+AL Repair would have noninferior clinical and radiological outcomes with respect to International Knee Documentation Committee (IKDC) scores, knee laxity parameters, and magnetic resonance imaging (MRI) characteristics. Furthermore, it was hypothesized that patients undergoing repair would have significantly better Forgotten Joint Score-12 (FJS-12) values and shorter times to return to the preinjury level of sport, without any increase in the rate of ipsilateral second ACL injury.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Consecutive patients evaluated with an acute ACL tear were considered for study eligibility. ACLR+LET was only performed when intraoperative tear characteristics contraindicated ACL repair. Patient-reported outcome measures such as the IKDC score, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS); reinjury rates; anteroposterior side-to-side laxity difference; and MRI characteristics were reported at a minimum follow-up of 2 years. The noninferiority study was based on the IKDC subjective score; side-to-side anteroposterior laxity difference; and signal-to-noise quotient (SNQ). The noninferiority margins were defined using the existing literature. An a priori sample size calculation was performed using the IKDC subjective score as the primary outcome measure.

RESULTS

A total of 100 patients (47 ACLR+LET, 53 ACL+AL Repair) with a mean follow-up of 25.2 months (range, 24-31 months) were enrolled and underwent surgery within 15 days of injury. At the final follow-up, the differences between groups with respect to the IKDC score, anteroposterior side-to-side laxity difference, and SNQ did not exceed noninferiority thresholds. ACL+AL Repair was associated with a shorter time to return to the preinjury level of sport (ACL+AL Repair: mean, 6.4 months; ACLR+LET: mean, 9.5 months; P < .01), better FJS-12 values (ACL+AL Repair: mean, 91.4; ACLR+LET: mean, 97.4; P = .04), and a higher proportion of patients achieving the Patient Acceptable Symptom State (PASS) for the KOOS subdomains studied (Symptoms: 90.2% vs 67.4%, P = .005; Sport and Recreation: 94.1% vs 67.4%, P < .001; Quality of Life: 92.2% vs 73.9%, P = .01). There were no significant differences between groups with respect to ipsilateral second ACL injury rates (ACL+AL Repair group, 3.8% and ACLR+LET group, 2.1% [n = 1]; P = .63).

CONCLUSION

ACL+AL Repair yielded clinical outcomes that were noninferior to (or not significantly different from) ACLR+LET with respect to IKDC subjective, Tegner activity level, and Lysholm scores; knee laxity parameters; graft maturity; and rates of failure and reoperation. However, there were significant advantages of ACL+AL Repair, including a shorter duration of time to return to the preinjury level of sport, better FJS-12 values, and a higher proportion of patients achieving PASS for KOOS subdomains studied (Symptoms, Sport and Recreation, Quality of Life).

Effect of Cross-sectional Area of the Hamstring Tendon Autograft on Failure Rate or Clinical Outcomes After Double-Bundle ACL Reconstruction: Tendon Autograft

Background

In previous studies examining the relationship between graft size and failure rate after anterior cruciate ligament reconstruction (ACLR), graft size was determined as diameter of the bone tunnel, and graft failure was defined as revision surgery. Consequently, the correlation between graft size and postoperative recurrent instability could not be assessed.

Purpose

(1) To intraoperatively measure the cross-sectional area (CSA) of the hamstring tendon (HT) autograft and compare the CSA of the autograft with the bone tunnel and (2) to assess the effect of the graft CSA on postoperative graft failure among patients who underwent double-bundle ACLR.

Study Design

Case-control study; Level of evidence, 3.

Methods

The study included 129 patients who underwent double-bundle ACLR using an HT autograft (mean ± SD age, 16.7 ± 1.7 years; all with a Tegner activity level ≥6). All patients had a minimum follow-up of 2 years. During surgery, the graft CSA was measured using an area micrometer, combining the anteromedial (AM) and posterolateral (PL) grafts. The total area of the bone tunnel was defined as the combined CSAs of the AM and PL tunnels as calculated by the diameter of the drill. The relationship between the CSAs of the combined HT graft and the bone tunnel was statistically compared, as was the relationship between graft CSAs and graft failure, defined as reinjury, recurrent instability manifested as quantitative laxity measurement, or revision ACLR.

Results

The CSAs of the midsubstance of the combined AM and PL graft significantly correlated with those of the bone tunnels (femoral side, R ² = 0.334, P < .0001; tibial side, R ² = 0.421, P < .0001). As for the relationship between the graft CSA and ACLR failure, there was no significant difference in the graft CSAs between the groups with and without graft failure in any of the failure criteria (P = .188).

Conclusion

The graft CSA was not a predictor of early failure after double-bundle ACLR using an HT autograft in this patient population.

High initial graft tension is a post-operative risk factor for high UTE T2* value of the graft 6 months after anterior cruciate ligament reconstruction

BACKGROUND

To evaluate the risk factor of "ligamentization" using the ultrashort echo time (UTE)-T2* imaging.

METHODS

Fifty-nine patients (23 males and 36 females, age of 21.9 ± 10.6 years old) who underwent anterior cruciate ligament (ACL) reconstruction with hamstring tendon were evaluated. The UTE T2* values of the reconstructed ACL at 6 months postoperatively were calculated. Circular regions of interest (5-10 mm²) were set at the proximal, mid-substance, and distal regions of the reconstructed ACL. The UTE T2* values of the entire reconstructed ACL were calculated as the average of these three points. Patients were divided into high (27 knees) and low (32 knees) UTE T2* groups by calculating whether their UTE T2* values were greater than the median of the UTE T2* values of all patients. Risk factors for high UTE T2* values were evaluated. Clinical outcomes were compared between the two groups.

RESULTS

There were no significant differences in any measured parameters and clinical outcomes between the two UTE T2* groups. Logistic regression analysis revealed that graft tension was a significant risk factor for patients with high UTE-T2* values (P = 0.047, odds ratio [OR] = 2.285). The UTE-T2* values of the 20 N graft tension using the Tension loc system were significantly lower than those of the 40 N using double-spike plate (DSP) with screws at each site and the 30 N using the Tension loc system at the distal site.

CONCLUSIONS

Higher graft tension was an independent risk factor for high UTE T2* values of the reconstructed ACL.

Magnetic Resonance Imaging Assessment of Hamstring Graft Healing and Integration 1 and Minimum 2 Years after ACL Reconstruction

BACKGROUND

An increase has been seen in the number of studies of anterior cruciate ligament reconstruction (ACLR) that use magnetic resonance imaging (MRI) as an outcome measure and proxy for healing and integration of the reconstruction graft. Despite this, the MRI appearance of a steady-state graft and how long it takes to achieve such an appearance have not yet been established.

PURPOSE

To establish whether a hamstring tendon autograft for ACLR changes in appearance on MRI scans between 1 and 2 years and whether this change affects a patient's ability to return to sports.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with hamstring tendon autograft ACLR underwent MRI and clinical outcome measures at 1 year and at a final follow-up of at least 2 years. MRI graft signal was measured at multiple regions of interest using oblique reconstructions both parallel and perpendicular to the graft, with lower signal indicative of better healing and expressed as the signal intensity ratio (SIR). Changes in tunnel aperture areas were also measured. Clinical outcomes were side-to-side anterior laxity and patient-reported outcome measures (PROMs).

RESULTS

A total of 42 patients were included. At 1 year, the mean SIR for the graft was 2.7 ± 1.2. Graft SIR of the femoral aperture was significantly higher than that of the tibial aperture (3.4 ± 1.3 vs 2.6 ± 1.8, respectively; P = .022). Overall, no significant change was seen on MRI scans after 2 years; a proximal graft SIR of 1.9 provided a sensitivity of 96% to remain unchanged. However, in the 6 patients with the highest proximal graft SIR (>4) at 1 year, a significant reduction in signal was seen at final follow-up (P = .026), alongside an improvement in sporting level. A significant reduction in aperture area was also seen between 1 and 2 years (tibial, -6.3 mm², P < .001; femoral, -13.3 mm², P < .001), which was more marked in the group with proximal graft SIR >4 at 1 year and correlated with a reduction in graft signal. The patients had a high sporting level; the median Tegner activity score was 6 (range, 5-10), and a third of patients scored either 9 or 10. Overall, PROMs and knee laxity were not associated with MRI appearance.

CONCLUSION

In the majority of patients, graft SIR on MRI did not change significantly after 1 year, and a proximal graft SIR <2 was a sensitive indicator for a stable graft signal, implying healing. Monitoring is proposed for patients who have a high signal at 1 year (proximal graft SIR >4), because a significant reduction in signal was seen in the second year, indicative of ongoing healing, alongside an improvement in sporting level. A reduction in tunnel aperture area correlated with a reduction in graft SIR, suggesting this could also be a useful measure of graft integration.

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.

Transtibial pull-out repair of lateral meniscus posterior root is beneficial for graft maturation after anterior cruciate ligament reconstruction: a retrospective study

PURPOSE

To determine the repair of LMPR lesions would improve the ACL graft maturation.

METHOD

A total of 49 patients underwent ACL reconstruction were included in this study. Patients were furtherly sub-grouped according to the status of LMPR: intact (17), repair (16) and resected (16). Assessments performed pre- and 2 years post-operatively included patients-reported scores and arthrometer side-to-side difference. Magnetic resonance imaging was used 2 years after the surgery to compare the lateral meniscal extrusion (LME), anterior tibial subluxation of the medial compartment (ATSMC), anterior tibial subluxation of the lateral compartment (ATSLC), the difference of ATSMC and ATSLC, and signal/noise quotient (SNQ) of ACL graft.

RESULTS

In LMPR resected group, it showed greater post-operative ATSMC-ATSLC difference when compared with pre-operatively (P = 0.006) and with the other 2 groups (intact: P = 0.031; repair: P = 0.048). SNQ of ACL graft was higher in LMPR resected group than those in LMPR intact (P = 0.004) and repair group (P = 0.002). The LMPR repair group showed significant reduction in LME post-operatively (P = 0.001). Post-operative measures on ATSLC-ATSMC difference (β = 0.304, P = 0.049) and LME (β = 0.492, P = 0.003) showed significant association with graft SNQ.

CONCLUSIONS

Transtibial repair of LMPR concomitant with ACL reconstruction restored translational stability, reduced meniscus extrusion, making it beneficial for ACL graft maturation.

Tibial slope, remnant preservation, and graft size are the most important factors affecting graft healing after ACL reconstruction

PURPOSE

The aim of this study was to determine the anatomic, operative and biological factors that influenced graft healing after single-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

One hundred fourteen consecutive patients who underwent anatomic single-bundle ACL reconstruction with quadrupled hamstring tendon autografts between 2016 and 2019 were retrospectively analyzed. Ninety-four patients met the inclusion criteria with minimum follow-up of 12 months. Patients were evaluated with multiple clinical measurements, including International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Lyshom Scores, and Marx activity scale. To evaluate graft healing, the signal-to-noise quotient (SNQ) was measured at intra-articular graft and intra-tunnel integration were evaluated on magnetic resonance imaging (MRI) at one year after surgery. Potential factors affecting graft healing, including age, sex, body mass index, time from injury to surgery, posterior tibial slope, lateral femoral condyle ratio, notch width index, meniscal injury, remnant preservation, tunnel aperture locations, graft size, graft bending angle, graft/remaining notch volume ratio were evaluated for their association with graft SNQ value by stepwise regression analysis.

RESULTS

A total of 94 patients were evaluated with mean follow-up 28.5 ± 9 months. Univariate regression analysis showed that posterior tibial slope, notch width index, remnant preserving procedure, high femoral tunnel, anterior tibial tunnel, graft bending angle, and graft/remaining notch volume ratio significantly associated with graft SNQ values. Multivariate regression analysis showed that lateral tibial slope, remnant preservation, and graft/remaining notch volume ratio were independent factors correlated with graft SNQ values. Also, the graft SNQ values was weakly correlated with femoral tunnel integration and Marx activity scale at one year. There was no correlation between graft SNQ values and IKDC-SKF and Lysholm scores. There was no correlation between graft SNQ values and International Knee Documentation Committee and Lysholm scores.

CONCLUSIONS

Tibial slope, remnant preservation and graft/remaining notch volume ratio were significant independent associated factors of graft SNQ value at one year. The graft SNQ values were also weakly correlated with femoral tunnel integration and the Marx activity scale. These factors should be taken into account for ensuring the ideal graft healing and for the return to sport decision-making.

LEVEL OF EVIDENCE

Level IV.

ACL reconstruction with femoral and tibial adjustable versus fixed-loop suspensory fixation: a retrospective cohort study

Background

Cortical suspensory fixation (CSF) devices gain more and more popularity as a reliable alternative to interference screws for graft fixation in anterior cruciate ligament (ACL) reconstruction. Adjustable-loop fixation may be associated with increased anterior laxity and inferior clinical outcome. The purpose of the study was to compare anterior laxity and clinical outcome after minimally invasive all-inside ACL reconstruction using an adjustable-loop (AL) to a standard technique with a fixed-loop (FL) CSF device.

Methods

Patients who underwent primary single-bundle ACL reconstruction with a quadrupled hamstring autograft at a single institution between 2012 and 2016 were reviewed. In the AL group minimally invasive popliteal tendon harvesting was performed with an all-inside approach (femoral and tibial sockets). In the FL group a traditional anteromedial approach was used for tendon harvesting and a femoral socket and full tibial tunnel were drilled. An objective clinical assessment was performed with Telos x-rays and the International Knee Documentation Committee (IKDC) Objective Score. Patient-reported outcomes (PRO) included the IKDC Subjective Score, the Lysholm Knee Score, the Knee Injury and Osteoarthritis Score (KOOS) and the Tegner Activity Scale.

Results

A total of 67 patients were enrolled in this retrospective study with a mean follow-up of 4 (± 1.5) years. The groups were homogenous at baseline regarding age, gender, and the time to surgery. At follow-up, no statistically significant differences were found regarding anterior laxity (AL: 2.3 ± 3 mm vs. FL: 2.3 ± 2.6 mm, p = 0.981). PRO scores were comparable between the AL and FL groups (IKDC score, 84.8 vs. 88.8, p = 0.185; Lysholm 87.3 vs. 89.9, p = 0.380; KOOS 90.7 vs. 91.4, p = 0.720; Tegner 5.5 vs. 6.2, p = 0.085). The rate of saphenous nerve lesions was significantly lower in the AL group with popliteal harvesting of the tendon (8.3% vs. 35.5%, p = 0.014).

Conclusion

The use of an adjustable-loop device on the femoral and tibial side led to similar stability and clinical results compared to a fixed-loop device.

Posterior Tibial Slope in Patients With Torn ACL Reconstruction Grafts Compared With Primary Tear or Native ACL: A Systematic Review and Meta-analysis

Background:

Increased posterior tibial slope (PTS) is a risk factor for anterior cruciate ligament (ACL) rupture and failure of ACL reconstruction (ACLR) grafts.

Purpose:

The purpose was to conduct a systematic review of literature on PTS measurements and to conduct a meta-analysis of comparable PTS measurements based on a patient’s ACL status. It was hypothesized that patients with torn ACLR grafts would have significantly larger medial and lateral PTS compared with patients with native ACLs or those who underwent primary ACLR.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included were studies that reported medial and/or lateral PTS measurements, those that reported PTS measurements based on ACL status (ie, intact ACL, primary ACL tear, failed ipsilateral ACLR, or revision ACLR), and those that reported their specific PTS measurement technique. Average PTS measurements, measurement location (medial or lateral tibial plateau) and technique, imaging modality used, and ACL status were extracted from each study. Data were pooled using DerSimonian and Laird random-effects models, and results were compared using the Altman interaction test.

Results:

The literature search identified 1705 studies, of which 82 (N = 12,971 patients) were included. There were 4028 patients in the intact ACL group (31%), 7405 in the primary ACLR group (57%), and 1538 in the failed ACLR group (12%). Measurements were obtained from lateral radiographs in 31 studies (38%), from magnetic resonance imaging in 47 studies (57%), and from computed tomography in 4 studies (5%). The failed ACLR group had a significantly larger lateral PTS (9.55°; 95% CI, 8.47°-10.63°) than either the primary ACL tear (7.13°; 95% CI, 6.58°-7.67°) or intact ACL (5.57°; 95% CI, 5.03°-6.11°) groups (P < .001 for both). The failed ACLR group also had a significantly larger medial PTS (9.05°; 95% CI, 7.80°-10.30°) than the primary (6.24°; 95% CI, 5.71°-6.78°) or intact ACL (6.28°; 95% CI, 5.21°-7.35°) groups (P < .001 for both).

Conclusion:

Both lateral and medial PTS measurements were greater in patients who had failed previous ACLR than those with a primary ACL tear or an intact native ACL. The lateral PTS of patients with primary ACL tears was greater than those with an intact native ACL.

Does remnant tissue preservation in anterior cruciate ligament reconstruction influence the creation of the rectangular femoral tunnel?

PURPOSE

We have previously described anterior cruciate ligament reconstruction with a rounded rectangular femoral tunnel created using a rounded rectangular dilator designed to enable a more anatomical and wider tendon-bone junction. However, the influence of remnant tissue preservation on the creation of the rounded rectangular femoral tunnel is not clear. This study aimed to evaluate the influence of remnant tissue preservation on the creation of the rounded rectangular femoral tunnel.

METHODS

A total of 198 patients who underwent primary anterior cruciate ligament reconstruction with a rounded rectangular femoral tunnel were evaluated retrospectively. Patients were categorized into a remnant preservation group (group P) and a non-preservation group (group N). Computed tomography images taken 1 week postoperatively were analyzed. The location of the rounded rectangular femoral tunnel evaluated using the quadrant method, its rotation angle, and the graft bending angle were compared between the two groups. The differences and the variance in femoral tunnel assessment were compared using the two-sample t-test and Levene's test.

RESULTS

Although there was no significant difference in the location of femoral tunnel for the deep/shallow direction along the Blumensaat's line (difference, p = .326; variances, p = .970), the tunnel was significantly lower in group P than in group N, with no variances (difference, p = .001; variances, p = .326). There were no significant differences and no variances in the tunnel rotation angle and the graft bending angle (difference, p = .727 and 0.514, respectively; variances, p = .827 and .445, respectively). Blow out of the posterior wall of the medial aspect of the femoral lateral condyle was an intraoperative complication that occurred in one case in group N.

CONCLUSION

The remnant preservation approach creates a lower femoral tunnel compared to the non-preservation technique. However, a rounded rectangular femoral tunnel can be created safely and is reproducible with remnant tissue preservation.

Anterior cruciate ligament autograft maturation on sequential postoperative MRI is not correlated with clinical outcome and anterior knee stability

PURPOSE

Magnetic resonance imaging (MRI) signal intensity is correlated to structural postoperative changes of the anterior cruciate ligament (ACL) autograft. The purpose of this study was to investigate the ACL autograft maturation process via MRI over 2 years postoperatively, compare it to a native ACL signal and correlate the results with clinical outcome, return to preinjury sports levels, and knee laxity measurements.

METHODS

ACL autograft signal intensity was measured in 17 male patients (age, 28.3 ± 7.0 years) who underwent ACL reconstruction with hamstring autograft at 6 weeks, 3-, 6-, 12-, and 24 months postoperatively by 3 Tesla MRI. Controls with an intact ACL served as control group (22 males, 8 females; age, 26.7 ± 6.8 years). An ACL/PCL ratio (APR) and ACL/muscle ratio (AMR) was calculated to normalize signals to soft tissue signal. APR and AMR were compared across time and to native ACL signal. Clinical outcome scores (IKDC, Lysholm), return to preinjury sports levels (Tegner activity scale), and knee laxity measurement (KT-1000) were obtained and correlated to APR and AMR at the respective time points.

RESULTS

The APR and AMR of the ACL graft changed significantly from the lowest values at 6 weeks to reach the highest intensity after 6 months (p < 0.001). Then, the APR and AMR were significantly different from a native ACL 6 months after surgery (p < 0.01) but approached the APR and AMR of the native ACL at 1- and 2 years after surgery (p < 0.05). The APR changed significantly during the first 2 years postoperatively in the proximal (p < 0.001), mid-substance (p < 0.001), and distal (p < 0.01) intraarticular portion of the ACL autograft. A hypo-intense ACL MRI signal was associated with return to the preinjury sports level (p < 0.05). No correlation was found between ACL MRI graft signal and clinical outcome scores or KT-1000 measurements.

CONCLUSION

ACL grafts undergo a continuous maturation process in the first 2 years after surgery. The ACL graft signals became hyper-intense 6 months postoperatively and approximated the signal of a native intact ACL at 12- and 24 months. Patients with a hypo-intense ACL graft signal at 2 years follow-up were more likely to return to preinjury sports levels. The results of the present study provide a template for monitoring the normal ACL maturation process via MRI in case of prolonged clinical symptoms. However, subjective outcome and clinical examination of knee laxity remain important to assess the treatment success and to allow to return to sports.

LEVEL OF EVIDENCE

III.

Graft tunnel integration occurs early in the tibial tunnel compared with the femoral tunnel after anterior cruciate ligament reconstruction with preserved insertion hamstring tendon graft

BACKGROUND

Preservation of hamstring tendon insertion at the time of anterior cruciate ligament (ACL) reconstruction is a well-known technique; however, its effect on graft integration is not well studied. The present study was conducted to study the graft integration inside the tibial and femoral tunnels, respectively, after ACL reconstruction using hamstring tendon graft with preserved insertion.

METHODS

Twenty-five professional athletes who underwent ACL reconstruction using hamstring tendon graft with preserved tibia insertion were enrolled in the study. Functional outcomes were checked at final follow-up using Lysholm score and Tegner activity scale. Magnetic resonance imaging (MRI) was done at 8 months and 14 months follow-up to study the graft tunnel integration of the ACL graft at both tibial and femoral tunnels.

RESULTS

The mean Fibrous interzone (FI) score (tibial tunnel) decreased from 2.61 (1-5) at 8 months to 2.04 (1-4) at 14 months follow-up (p = 0.02). The mean FI score (femoral side) decreased from 3.04 (2-5) at 8 months to 2.57 (2-4) at 14 months (p = 0.02).

CONCLUSIONS

Graft integration occurs early in the tibial tunnel as compared with the femur tunnel with preserved insertion hamstring tendon autograft. Trial registration CTRI/2019/07/020320 [registered on 22/07/2019]; http://www.ctri.nic.in/Clinicaltrials/pdf_generate.php?trialid=33884&EncHid=&modid=&compid=%27,%2733884det%27.

Four-Tunnel Double-Bundle Posterior Cruciate Ligament Reconstruction With Remnant Preservation

The clinical results of posterior cruciate ligament reconstruction (PCL) still leave much room for improvement. To get better knee stability, the double-bundle reconstruction, the use of strong grafts, and the preservation of the remnant have been applied. However, the combination of the 3 measures has seldom been reported. Thus I introduce a 4-tunnel double-bundle PCL reconstruction technique, in which I combine the use of strong grafts and preservation of the remnant. The critical point of this technique is manipulating skillfully across the femoral notch with the preservation, as well as the hindrance to operation of the PCL remnant. My clinical experience indicates this technique is somewhat complicated but most effective. I believe the introduction of this technique will provide an additional choice when PCL reconstruction is to be performed.

Sagittal Inclination Angle of Graft Is Associated With Knee Stability After Anatomic Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate whether the sagittal inclination angle (SIA) of a graft is associated with postoperative knee stability after anatomic anterior cruciate ligament (ACL) reconstruction.

METHODS

All patients who had undergone anatomic ACL reconstruction between April 2014 and September 2015 in addition to volunteers with no history of knee injury were eligible for inclusion in this study. The patients were evaluated by magnetic resonance imaging of the knee in full extension at 1 year after surgery, as were volunteers. The posterior tibial slope (PTS) angle and the SIA of the intact ACL and reconstructed graft were measured relative to each medial and lateral tibial plateau. The patients were examined for knee stability by the side-to-side difference in the anterior tibial translation on stress radiographs at minimum 2-year follow-up.

RESULTS

We included 43 patients (26 male, 17 female, mean age 32.8 ± 14.8 years) and 12 volunteers (7 male, 5 female, mean age 28.7 ± 3.1 years) as normal controls. The mean follow-up duration was 29.8 ± 3.6 months. The mean PTS angle and mean SIA in the patients did not significantly differ from those of the intact ACL. The PTS angle in the patients was not significantly correlated with postoperative side-to-side difference in the anterior tibial translation. However, the graft SIA was significantly correlated with the postoperative anterior tibial translation (medial SIA; r = 0.42, P = .005, lateral SIA; r = 0.52, P < .001).

CONCLUSIONS

Even if anatomically reconstructed, the graft SIA in reference to the tibial plateau at full knee extension is variable and is associated with postoperative knee stability. The larger graft SIA was correlated with graft laxity after anatomic ACL reconstruction.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Comparison of hamstring and quadriceps strength after anatomical versus non-anatomical anterior cruciate ligament reconstruction: a retrospective cohort study

Background

Strength recovery of injured knee is an important parameter for patients who want to return to sport after anterior cruciate ligament reconstruction (ACLR). Comparison of muscle strength between anatomical and non-anatomical ACLR has not been reported.

Purpose

To evaluate the difference between anatomical and non-anatomical single-bundle ACLR in hamstring and quadriceps strength and clinical outcomes.

Methods

Patients received unilateral primary single-bundle hamstring ACLR between January 2017 to January 2018 were recruited in this study. Patients were divided into anatomical reconstruction group (AR group) and non-anatomical reconstruction group (NAR group) according to femoral tunnel aperture position. The hamstring and quadriceps isokinetic strength including peak extension torque, peak flexion torque and H/Q ratio were measured at an angular velocity of 180°/s and 60°/s using an isokinetic dynamometer. The isometric extension and flexion torques were also measured. Hamstring and quadriceps strength were measured preoperatively and at 3, 6, and 12 months after surgery. Knee stability including Lachman test, pivot-shift test, and KT-1000 measurement and subjective knee function including International Knee Documentation Committee (IKDC) and Lysholm scores were evaluated during the follow-up.

Results

Seventy-two patients with an average follow-up of 30.4 months (range, 24–35 months) were included in this study. Thirty-three were in AR group and 39 in NAR group. The peak knee flexion torque was significant higher in AR group at 180°/s and 60°/s (P < 0.05 for both velocity) at 6 months postoperatively and showed no difference between the two groups at 12 months postoperatively. The isometric knee extension torque was significant higher in AR group at 6 months postoperatively (P < 0.05) and showed no difference between the two groups at 12 months postoperatively. No significant differences between AR group and NAR group were found regarding knee stability and subjective knee function evaluations at follow-up.

Conclusions

Compared with non-anatomical ACLR, anatomical ACLR showed a better recovery of hamstring and quadriceps strength at 6 months postoperatively. However, the discrepancy on hamstring and quadriceps strength between the two groups vanished at 1 year postoperatively.

Magnetic Resonance Imaging 1 Year After Hamstring Autograft Anterior Cruciate Ligament Reconstruction Can Identify Those at Higher Risk of Graft Failure: An Analysis of 250 Cases

BACKGROUND

There is currently no analysis of 1-year postoperative magnetic resonance imaging (MRI) that reproducibly evaluates the graft of a hamstring autograft anterior cruciate ligament reconstruction (ACLR) and helps to identify who is at a higher risk of graft rupture upon return to pivoting sports.

PURPOSE

To ascertain whether a novel MRI analysis of ACLR at 1 year postoperatively can be used to predict graft rupture, sporting level, and clinical outcome at a 1-year and minimum 2-year follow-up.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Graft healing and integration after hamstring autograft ACLR were evaluated using the MRI signal intensity ratio at multiple areas using oblique reconstructions both parallel and perpendicular to the graft and tunnel apertures. Clinical outcomes were assessment of side-to-side laxity and International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Lysholm, and Tegner activity level scores at 1 year. Repeat outcome measures and detection of graft rupture were evaluated at a minimum of 2 years.

RESULTS

A total of 250 patients (42.4% female) underwent MRI analysis at 1 year, and assessment of 211 patients between 1 year and the final follow-up (range, 24-36 months) detected 9 graft ruptures (4.3%; 5 in female patients). A significant predictor for graft rupture was a high signal parallel to the proximal intra-articular graft and perpendicular to the femoral tunnel aperture (P = .032 and P = .049, respectively), with each proximal graft signal intensity ratio (SIR) increase by 1 corresponding to a 40% increased risk of graft rupture. A cutoff SIR of 4 had a sensitivity and specificity of 66% and 77%, respectively, in the proximal graft and 88% and 60% in the femoral aperture. In all patients, graft signal adjacent to and within the tibial tunnel aperture, and in the mid intra-articular portion, was significantly lower than that for the femoral aperture (P < .001). A significant correlation was seen between the appearance of higher graft signal on MRI and those patients achieving top sporting levels by 1 year.

CONCLUSION

ACLR graft rupture after 1 year is associated with MRI appearances of high graft signal adjacent to and within the femoral tunnel aperture. Patients with aspirations of quickly returning to a high sporting level may benefit from MRI analysis of graft signal. Graft signal was highest at the femoral tunnel aperture, adding further radiographic evidence that the rate-limiting step to graft healing occurs proximally.

Inferior Medial Geniculate Artery Branch as an Anatomical Landmark for Hamstring Harvest During Anterior Cruciate Ligament Reconstruction

Graft harvesting is often a challenging step of anterior cruciate ligament reconstructions. Accurate isolation of the hamstring tendons at the pes anserinus is crucial to successful graft harvesting. We describe a technique of using a branch of the inferior medial geniculate artery overlying the pes anserinus insertion as an anatomical landmark to localize the hamstring tendons for harvest. By using this vessel as an anatomical landmark, the incision length was decreased and the time required to harvest reduced. This is a highly reproducible technique and will be beneficial for soft tissue harvesting surgeons to ease hamstring graft harvesting.

The space available for the anterior cruciate ligament in the intercondylar notch is less in patients with ACL injury

PURPOSE

The aim of this study was to determine if a difference exists in the relationship between the femoral intercondylar notch volume, and the volumes of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in ACL injured patients and healthy subjects.

METHODS

Intact knees of 19 healthy subjects and bilateral knees of 18 ipsilateral ACL reconstructed patients were scanned using 3-tesla high-resolution magnetic resonance imaging. The intercondylar notch, ACL, PCL and hamstring graft were segmented using three-dimensional (3D) processing software. The native intercondylar notch, ACL, and PCL volumes were compared between both groups. The volumes of native ACL and graft were compared in ACL injured patients.

RESULTS

The following volumes showed no significant differences between the ACL injured group and control group; intercondylar notch (9.9 ± 2.3 vs 9.6 ± 1.7 cm³), ACL (2.4 ± 0.7 vs 2.4 ± 0.6 cm³) and PCL (3.9 ± 1.0 vs 3.4 ± 0.8 cm³), and the ratio of the ACL to the intercondylar notch (24.6 ± 5.0 vs 25.4 ± 2.9%). There was a significant difference in the ratio of PCL to the intercondylar notch (39.1 ± 4.3 vs 35.9 ± 4.9%, p = 0.023). The graft was significantly larger than native ACL volume (3.0 ± 0.7 vs 2.4 ± 0.7 cm³, p = 0.012).

CONCLUSIONS

The ratio of the PCL volume in the femoral intercondylar notch was higher in the ACL injured group compared to the healthy control group, despite the ratio of ACL volume in the femoral intercondylar notch being similar in both groups. A greater awareness of the potentially limited space for the graft alongside the PCL within the femoral intercondylar notch may allow surgeons a more informed choice of graft type and size.

LEVEL OF EVIDENCE

IV.