Anteromedial versus transtibial technique in single-bundle autologous hamstring ACL reconstruction: a meta-analysis of prospective randomized controlled trials

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

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

Effect of anteromedial portal location on femoral tunnel inclination, length, and location in hamstring autograft-based single-bundle anterior cruciate ligament reconstruction: a prospective study

BACKGROUND

Portal positioning in arthroscopic anterior cruciate ligament reconstruction is critical in facilitating the drilling of the femoral tunnel. However, the traditional approach has limitations. A modified inferior anteromedial portal was developed. Therefore, this study aims to compare the modified and conventional far anteromedial portals for femoral tunnel drilling, assessing factors such as tunnel length, inclination, iatrogenic chondral injury risk, and blowout.

MATERIAL AND METHODS

Patients scheduled for hamstring autograft-based anatomical single-bundle arthroscopic anterior cruciate ligament reconstruction were divided into two groups: modified and far anteromedial groups. Primary outcomes include differences in femoral tunnel length intraoperatively, tunnel inclination on anteroposterior radiographs, and exit location on lateral radiographs. Secondary outcomes encompass tunnel-related complications and reconstruction failures. To identify potential risk factors for shorter tunnel lengths and posterior exits, regression analysis was conducted.

RESULTS

Tunnel parameters of 234 patients were analyzed. In the modified portal group, femoral tunnel length and inclination were significantly higher, with tunnels exhibiting a more anterior exit position (p < 0.05). A higher body mass index exerted a negative influence on tunnel length and inclination. However, obese patients in the modified portal group had longer tunnels, increased inclination, and a lower risk of posterior exit. Only a few tunnel-related complications were observed in the far anteromedial group.

CONCLUSION

The modified portal allowed better control of tunnel length and inclination, ensuring a nonposterior femoral tunnel exit, making it beneficial for obese patients.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Current trends in graft choice for primary anterior cruciate ligament reconstruction - part II: In-vivo kinematics, patient reported outcomes, re-rupture rates, strength recovery, return to sports and complications

Postoperative patient satisfaction after anterior cruciate ligament reconstruction (ACL-R) is influenced mainly by the degree of pain, the need for reoperation, and functional performance in daily activities and sports. Graft choice has shown to have an influence on postoperative outcomes after ACL-R. While patient reported outcomes measurements do not differ between graft options, evidence shows that normal knee kinematics is not fully restored after ACL-R with an increase in postoperative anterior tibial translation (ATT). Postoperative graft rupture rates seem to favor bone-patella-tendon-bone (BPTB) and quadriceps tendon (QT) autografts over HT or allografts. While return to sports rates seem comparable between different graft types, postoperative extensor strength is reduced in patients with BPTB and QT whereas flexion strength is weakened in patients with HT. Postoperative donor site morbidity is highest in BPTB but comparable between HT and QT. With all graft options having advantages and drawbacks, graft choice must be individualized and chosen in accordance with the patient.

Clinical outcome of anterior cruciate ligament reconstruction with modified transtibial and anteromedial portal

Arthroscopic ACL reconstruction is the current standard care of treatment for anterior cruciate ligament (ACL) injuries. Modified transtibial (mTT) and anteromedial portal (AMP) techniques aim at the anatomical placement of femoral tunnel. Controversy existed in the literature with regard to the outcome of these techniques. Hence, we designed a retrospective comparative study to analyse the clinical and functional outcomes of mTT and AMP techniques. We hypothesized that there would be no difference between the clinical and functional outcomes in mTT and AMP techniques. This retrospective observational study was conducted in consecutive patients who underwent arthroscopic ACL reconstruction using semitendinosus-gracilis (STG) quadrupled graft in our tertiary care centre with a minimum follow-up of two years. Out of 69 patients, 37 had undergone ACL reconstruction by mTT technique and remaining by AMP technique. All the patients were assessed clinically by anterior drawer, Lachman's, pivot shift and single-legged hop test. Lysholm Knee Scoring Scale and International Knee Documentation Committee (IKDC) subjective knee evaluation score were used for the functional status. Knee instability was assessed objectively by KT-1000 arthrometer. There was no statistically significant difference in baseline demographic characteristics between mTT and AMP groups. At the end of 2 years, no statistically significant difference was noted in the anterior drawer and Lachman's test. Though not significant, IKDC scores and Lysholm's scores showed a better outcome in the AMP group when compared to the mTT group. AMP group showed significantly better outcome with KT-1000 arthrometer. Based on the results obtained, we presume that overall both mTT and AMP have similar functional outcome. However, as AMP technique offers significantly improved subjective rotational stability on pivot shift test, better hop limb symmetry index and KT 1000 readings compared to mTT, we suggest AMP over mTT.

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

BACKGROUND

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

HYPOTHESIS

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

STUDY DESIGN

Meta-analysis; Level of evidence, 2.

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

PURPOSE/HYPOTHESIS

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

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

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

RESULTS

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

CONCLUSION

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

Evaluation of anterior cruciate ligament surgical reconstruction through finite element analysis

Anterior cruciate ligament (ACL) tear is one of the most common knee injuries. The ACL reconstruction surgery aims to restore healthy knee function by replacing the injured ligament with a graft. Proper selection of the optimal surgery parameters is a complex task. To this end, we developed an automated modeling framework that accepts subject-specific geometries and produces finite element knee models incorporating different surgical techniques. Initially, we developed a reference model of the intact knee, validated with data provided by the Open Knee(s) project. This helped us evaluate the effectiveness of estimating ligament stiffness directly from MRI. Next, we performed a plethora of “what-if” simulations, comparing responses with the reference model. We found that (a) increasing graft pretension and radius reduces relative knee displacement, (b) the correlation of graft radius and tension should not be neglected, (c) graft fixation angle of 20\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{\circ }$$\end{document}∘ can reduce knee laxity, and (d) single-versus double-bundle techniques demonstrate comparable performance in restraining knee translation. In most cases, these findings confirm reported values from comparative clinical studies. The numerical models are made publicly available, allowing for experimental reuse and lowering the barriers for meta-studies. The modeling approach proposed here can complement orthopedic surgeons in their decision-making.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level II.

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AIM

To analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique.

METHODS

From January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability.

RESULTS

Group B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups.

CONCLUSION

ACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.

ANALYSIS OF THE MECHANICAL BEHAVIOR OF THE POSTERIOR CRUCIATE LIGAMENT IN A PORCINE MODEL

INTRODUCTION

The knee has shown a significant increase in the frequency of injury due to sports practice. This increase and the improvement of surgical techniques of ligament reconstruction have led to a greater indication of this treatment to achieve a function close to normal.

OBJECTIVE

To conduct a preliminary analysis of the ligament behavior.

METHODS

The study consisted of the validation of an anatomical model of the pig, in which five models were subjected to mechanical tests. The data on the loads of the in situ model and the strains of the posterior cruciate ligament were collected.

RESULTS

The analysis of the tensile load showed, at first, a nonlinear increase in stresses. Subsequently, the pig's knee showed a relatively linear intermediate response until failure around 1,200 N. Strain × time showed a response of the posterior cruciate ligament, which also has a relatively linear response.

CONCLUSION

We observed a linear behavior in the range of 1,000 to 5,000 microstrains in the strain of the posterior cruciate ligament. We suggest further studies to understand knee ligaments regarding their behavior in their function. Level of Evidence IV, Biomechanical Study.

The Graft Insertion Length in the Femoral Tunnel During Anterior Cruciate Ligament Reconstruction With Suspensory Fixation and Tibialis Anterior Allograft Does Not Affect Surgical Outcomes but Is Negatively Correlated With Tunnel Widening

PURPOSE

To investigate the surgical outcomes of anterior cruciate ligament (ACL) reconstruction using a low-dose irradiated tibialis anterior allograft with a fixed-loop cortical suspension device for the femur based on the graft insertion length (GIL) in the femoral tunnel.

METHODS

Between January 2010 and January 2018, the medical records of consecutive patients who underwent arthroscopic ACL reconstruction with a tibialis anterior allograft fixed with the EndoButton CL for the femur and who had at least 2 years of follow-up were retrospectively evaluated. Patients were classified into 3 groups based on the GIL in the femoral tunnel (group 1, GIL < 15 mm; group 2, GIL of 15-20 mm; and group 3, GIL > 20 mm), and their functional scores, knee laxity, and radiographic parameters were evaluated.

RESULTS

A total of 91 patients were analyzed. There were no statistically significant differences in the functional scores and knee laxity between the 3 groups at 2 years postoperatively. However, significant differences were observed in tunnel widening at 1 year postoperatively in the femur (P = .045 for absolute value and P = .004 for relative value) and the tibia (P = .014 for absolute value and P = .012 for relative value), revealing that both the femoral and tibial tunnels widened as the GIL decreased. Additional linear regression analyses were performed to identify whether the GIL independently affects tunnel widening. Consequently, the femoral tunnel depth, tunnel diameter, and GIL were found to independently influence femoral tunnel widening (P = .008, P = .019, and P < .001, respectively), whereas the tunnel diameter and GIL affected tibial tunnel widening (P < .001 and P = .004, respectively).

CONCLUSIONS

The GIL in the femoral tunnel during ACL reconstruction using a tibialis anterior allograft with a fixed-loop cortical suspension device for the femur has no significant association with the postoperative functional outcomes and knee laxity, but it has a negative correlation with tunnel widening in the femur and the tibia.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

No differences in clinical outcomes and graft healing between anteromedial and central femoral tunnel placement after single bundle ACL reconstruction

PURPOSE

The purpose of this study was to compare clinical outcomes and graft healing after anterior cruciate ligament (ACL) reconstruction with anteromedial and central femoral tunnel placement.

METHODS

During 2016 and 2018, 110 consecutive patients underwent single bundle ACL reconstruction; 85 patients met the inclusion criteria, and each patient underwent 3D-CT within 1 week and MRI 1.5 years after the operation. The central point of the femoral tunnel and signal/noise quotient (SNQ) of three regions of interest (ROI) in the intra-articular graft were measured to analyse the tunnel position and graft healing extent. Clinical assessments, including functional scores, KT-2000 arthrometer measurements and pivot-shift tests, were evaluated at the 2-year follow-up. Patients were divided into two groups depending on the femoral tunnel position: the anteromedial position group (Group A) and the centre position group (Group B).

RESULTS

Seventy-one patients were available for the 2-year follow-up and MRI examination: 34 patients in Group A and 35 patients in Group B, and 2 patients were excluded for an eccentric tunnel position. No graft failure occurred, and compared with the preoperative assessment outcomes, the outcomes of both groups improved at the final follow-up. Group A was significantly better than Group B regarding the KT-2000 arthrometer measurements (P = 0.031). No significant differences were observed in terms of functional scores, pivot-shift test results, or the SNQ between groups.

CONCLUSIONS

No differences in clinical outcomes or graft healing were found between AM and central femoral tunnel placements in single bundle ACL reconstruction. Therefore, satisfactory clinical outcomes, knee stability and graft healing can be obtained for both femoral tunnel placements.

LEVEL OF EVIDENCE

II.

Comparison of Clinical Outcomes between Anteromedial and Transtibial Techniques of Single-Bundle Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

This study compared clinical outcomes obtained after single-bundle anterior cruciate ligament (ACL) reconstruction using the anteromedial (AM) and transtibial (TT) techniques, which comprise the conventional transtibial (cTT) and modified transtibial (mTT) techniques. This study included clinical randomized controlled trials and prospective and retrospective controlled trials with AM and TT techniques from the PubMed and Embase databases and the Cochrane Library. All databases were searched from January 2010 to July 2020. Two independent evaluators verified the quality of the included studies using the Cochrane Collaboration's risk of bias tool and the Newcastle-Ottawa Scale (NOS). Outcome measures analysed included the Lachman test, pivot-shift test, side-to-side difference (SSD), Lysholm score, Tegner activity scale, International Knee Documentation Committee (IKDC) grade and score. Ten randomized controlled trials (RCTs) and 16 prospective and retrospective controlled trials were included with a total of 2202 patients. There were 1180 patients and 1022 patients in the AM and TT groups, respectively. Compared to the cTT group, superior postoperative results were observed in the AM group based on the negative rate of the Lachman test and the pivot-shift test, IKDC grade and score, Lysholm score, Tegner activity scale and SSD (p < 0.05). However, there was no significant difference between the AM and mTT groups (p > 0.05). Compared to the conventional TT technique, the AM technique exhibited superior clinical outcomes. Nevertheless, the modified TT and AM techniques had comparable results. With neither of the techniques (mTT or AM) producing significantly superior outcomes, surgeons can choose either of them depending on their preferences.

[Progress of different methods for femoral tunnel positioning in anterior cruciate ligament reconstruction]

OBJECTIVE

To systematically review the progress of different methods for femoral tunnel positioning in anterior cruciate ligament (ACL) reconstruction and provide a clinical reference for treatment of ACL rupture.

METHODS

The literature about the femoral tunnel positioning in ACL reconstruction was widely reviewed. The advantages and disadvantages and the clinical results of each method were summarized.

RESULTS

Currently in ACL reconstruction, methods for femoral tunnel positioning include transtibial technique (TT), anteromedial technique (AM), outside-in (OI), modified TT (mTT), and computer assisted surgery. There is no significant difference in the postoperative effectiveness between TT technique and AM technique. Compared with the TT technique, the OI technique has higher rotational stability of knee, but there is no significant difference in clinical results. The femoral tunnel located by mTT technique is closer to the anatomical placement than that of TT technique, but mTT technique is not effective for systematically anatomic femoral tunnel positioning, and further research is needed to prove its advantages.

CONCLUSION

Different femoral tunnel positioning methods have their own advantages and disadvantages, and there is no definite evidence that one is superior than the rest.

Superior Postoperative Stability and Functional Outcomes With Anteromedial Versus Transtibial Technique of Single-Bundle Autologous Hamstring Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Prospective Randomized Controlled Trials

PURPOSE

The aim of this meta-analysis was to compare the postoperative stability and functional outcomes of anteromedial (AM)- and transtibial (TT)-based single-bundle hamstring anterior cruciate ligament (ACL) reconstruction techniques.

METHODS

A meta-analysis comparing the outcomes of single-bundle hamstring ACL reconstruction using the AM and TT techniques was performed. Prospective randomized controlled trials identified from searches of PubMed, Cochrane, and Embase were included in this review. The outcome measures analyzed included postoperative Lachman test and pivot-shift test results, side-to-side difference, International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity score.

RESULTS

A total of 7 randomized controlled trials (654 patients) were included in this review. The AM technique, compared with the TT technique, resulted in superior postoperative stability based on the negative Lachman test rate (risk ratio [RR], 1.12; 95% confidence interval [CI], 1.01 to 1.24; P = .03; 95% prediction interval [PI], 0.32 to 3.46), negative pivot-shift test rate (RR, 1.16; 95% CI, 1.06 to 1.28; P = .002; 95% PI, 0.40 to 2.88), and side-to-side difference (weighted mean difference [WMD], -0.32 mm; 95% CI, -0.48 to -0.16; P < .0001; 95% PI, -0.55 to -0.09). Likewise, the AM technique contributed to superior postoperative functional outcomes based on the proportion of IKDC grade A findings (RR, 1.16; 95% CI, 1.02 to 1.32; P = .03; 95% PI, 0.40 to 2.83) and the Lysholm score (WMD, 0.82; 95% CI, 0.23 to 1.41; P = .007; 95% PI, -0.22 to 1.86). However, the AM and TT techniques had comparable subjective IKDC scores (WMD, 0.98; 95% CI, -0.91 to 2.88; P = .31; 95% PI, -3.18 to 5.14) and Tegner activity scores (WMD, 0.32; 95% CI, -0.23 to 0.86; P = .25; 95% PI, -3.84 to 4.48).

CONCLUSIONS

The AM method of single-bundle hamstring ACL reconstruction results in superior postoperative stability and functional outcomes compared with the TT method.

LEVEL OF EVIDENCE

Level I, systematic review of Level I studies.

Editorial Commentary: Independent Femoral Tunnel Drilling Avoids Anterior Cruciate Ligament Graft Malpositioning: Advice From a Transtibial Convert

Optimal femoral anterior cruciate ligament graft placement has been extensively studied. The champions of transtibial reconstruction debate the backers of anteromedial portal and outside-in drilling. The holy grail is footprint restoration and how we best to get there. To me, creating the femur independently provides the best chance of finding that footprint by being unconstrained by the tibia. Anterior cruciate ligament surgery is challenging enough; decrease intraoperative stress and increase your likelihood of femoral footprint restoration by drilling it though the anteromedial portal.

ACL Reconstruction Graft Angle and Outcomes: Transtibial vs Anteromedial Reconstruction

BACKGROUND

The importance of creating an anatomic anterior cruciate ligament (ACL) reconstruction has been receiving significant attention. The best technique by which to achieve this anatomic reconstruction continues to be debated. The two most common methods are the transtibial (TT) and anteromedial (AM) techniques. Each has its advantages and disadvantages, and the literature comparing the two remains uncertain.

QUESTIONS/PURPOSES

In this prospective comparative study, we aimed to compare the ACL graft and tunnel angles achieved using the anatomic transtibial (TT) and anteromedial (AM) techniques; compare the ACL graft and tunnel angles in knees that have undergone ACL reconstruction and knees with intact ACLs; and determine whether differences in the graft or tunnel angle produce differences in clinical outcomes, as measured using both physical exam and patient-reported outcomes, after ACL reconstruction.

METHODS

Patients who underwent primary ACL reconstruction with bone-tendon-bone grafts using a TT or AM technique were included. Femoral graft angle (FGA), tibial graft angle (TGA), and sagittal orientation of the reconstructed ACL and contralateral native ACL were measured on post-operative magnetic resonance imaging. Post-operatively, patients underwent measurement of knee stability and completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) survey.

RESULTS

Twenty-nine patients were enrolled (AM group, 14; TT group, 15); at follow-up, KOOS data were available for 26 patients (13 in each group). There were no differences in sagittal ACL graft angle between groups or in comparison with the normal knee. The FGA was more vertical after TT reconstructions; the TGA was comparable between groups. There were no significant differences in 2-year post-operative physical exam measurements or in KOOS scores.

CONCLUSION

Anatomic ACL angle was restored after reconstruction with both the TT and AM techniques, despite different FGAs. No significant differences in clinical outcome were noted between groups on physical exam or KOOS at 2 years after surgery. These results suggest that TT reconstruction results in a graft position similar to that seen in AM reconstruction and that the location of the intra-articular tunnel aperture matters more than the orientation of the tunnel.

Trauma and femoral tunnel position are the most common failure modes of anterior cruciate ligament reconstruction: a systematic review

PURPOSE

To improve outcomes of anterior cruciate ligament reconstruction (ACLR), it is important to understand the reasons for failure of this procedure. This systematic review was performed to identify current failure modes of ACLR.

METHODS

A systematic search was performed using PubMed, EMBASE, Cochrane, and annual registries for ACLR failures. Studies were included when failure modes were reported (I) of ≥ 10 patients and (II) at a minimum of two-year follow-up. Modes of failure were also compared between different graft types and in femoral tunnel positions.

RESULTS

This review included 24 cohort studies and 4 registry-based studies (1 level I, 1 level II, 10 level III, and 16 level IV studies). Overall, a total of 3657 failures were identified. The most common single failure mode of ACLR was new trauma (38%), followed by technical errors (22%), combined causes (i.e. multiple failure mechanisms; 19%), and biological failures (i.e. failure due to infection or laxity without traumatic or technical considerations; 8%). Technical causes also played a contributing role in 17% of all failures. Femoral tunnel malposition was the most common cause of technical failure (63%). When specifically looking at the bone-patellar tendon-bone (BPTB) or hamstring (HT) autografts, trauma was the most common failure mode in both, whereas biological failure was more pronounced in the HT group (4% vs. 22%, respectively). Technical errors were more common following transtibial as compared to anteromedial portal techniques (49% vs. 26%).

CONCLUSION

Trauma is the single leading cause of ACLR failure, followed by technical errors, and combined causes. Technical errors seemed to play a major or contributing role in large part of reported failures, with femoral tunnel malposition being the leading cause of failure. Trauma was also the most common failure mode in both BPTB and HT grafts. Technical errors were a more common failure mode following transtibial than anteromedial portal technique.

LEVEL OF EVIDENCE

IV.

No difference in revision rates between anteromedial portal and transtibial drilling of the femoral graft tunnel in primary anterior cruciate ligament reconstruction: early results from the New Zealand ACL Registry

PURPOSE

The use of an accessory anteromedial portal to drill the femoral graft tunnel in primary anterior cruciate ligament (ACL) reconstruction was introduced in the 2000s in an effort to achieve a more anatomic femoral tunnel position. However, some early studies reported an increase in revision ACL reconstruction compared to the traditional transtibial technique. The aim of this study was to analyse recent data recorded by the New Zealand ACL Registry to compare outcomes of ACL reconstruction performed using the anteromedial portal and transtibial techniques.

METHODS

Analysis was performed on primary isolated single-bundle ACL reconstructions recorded between 2014 and 2018 by the New Zealand ACL Registry. Patients were categorised into two groups according to whether an anteromedial portal or transtibial technique was used to drill the femoral graft tunnel. The primary outcome was revision ACL reconstruction and was compared between both groups through univariate and multivariate survival analyses. The secondary outcomes that were analysed included subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Marx activity score.

RESULTS

Six thousand one hundred and eighty-eight primary single-bundle ACL reconstructions were performed using either the anteromedial portal or transtibial drilling techniques. The mean time of follow-up was 23.3 (SD ± 14.0) months. Similar patient characteristics such as mean age (29 years, SD ± 11), sex (males = 58% versus 57%) and time to surgery (median 4 months, IQR 5) were observed between both groups. The rate of revision ACL reconstruction was 2.6% in the anteromedial portal group and 2.2% in the transtibial group (n.s.). The adjusted risk of revision ACL reconstruction was 1.07 (95% CI 0.62-1.84, n.s.). Patients in the anteromedial portal group reported improved scores for subscales of the KOOS and higher Marx activity scores at 1-year post-reconstruction.

CONCLUSION

There was no difference in the risk of revision ACL reconstruction between the two femoral tunnel drilling techniques at short-term follow-up. We observed minor differences in patient-reported outcomes at 1-year follow-up favouring the anteromedial portal technique, which may not be clinically relevant. Surgeons can achieve good clinical outcomes with either drilling technique.

LEVEL OF EVIDENCE

III.

A Hybrid Transtibial Technique Combines the Advantages of Anteromedial Portal and Transtibial Approaches: A Prospective Randomized Controlled Trial

BACKGROUND

The anteromedial (AM) portal and transtibial (TT) approaches are 2 common anterior cruciate ligament (ACL) femoral tunnel drilling techniques, each with unique benefits and disadvantages. A hybrid TT (HTT) technique using medial portal guidance of a flexible TT guide wire has recently been described that may combine the strengths of both the AM portal and the TT approaches.

HYPOTHESIS

The HTT technique will achieve anatomic femoral tunnel apertures similar to the AM portal technique, with improved femoral tunnel length and orientation.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A total of 30 consecutive patients with primary ACL tears were randomized to undergo the TT, AM portal, or HTT technique for femoral tunnel positioning at the time of reconstruction. All patients underwent 3-dimensional computed tomography of the operative knee at 6 weeks postoperatively. Femoral and tibial tunnel aperture positions and tunnel lengths, as well as graft bending angles in the sagittal and coronal planes, were measured.

RESULTS

Tibial tunnel lengths and aperture positions were identical between the 3 groups. The AM portal and HTT techniques achieved identical femoral aperture positions in regard to both height (P = .629) and depth (P = .582). By contrast, compared with the AM portal and HTT techniques, femoral apertures created with the TT technique were significantly higher (P < .001 and P < .001, respectively) and shallower (P = .014 and P = .022, respectively) in the notch. The mean femoral tunnel length varied significantly between the groups, measuring 35.2, 41.6, and 54.1 mm for the AM portal, HTT, and TT groups, respectively (P < .001). Last, there was no difference between the mean coronal (P = .190) and sagittal (P = .358) graft bending angles between the TT and HTT groups. By contrast, compared with the TT and HTT techniques, femoral tunnels created with the AM portal technique were significantly more angulated in the coronal plane (17.7° [P < .001] and 12.5° [P = .006], respectively) and sagittal plane (13.5° [P < .001] and 10.5° [P = .013], respectively).

CONCLUSION

This prospective randomized controlled trial found that the HTT technique achieved femoral aperture positions equally as anatomic as the AM portal technique but produced longer, less angulated femoral tunnels, which may help reduce graft strain and mismatch. As such, this hybrid approach may represent a beneficial combination of both the TT and the AM portal techniques.

REGISTRATION

NCT02795247 (ClinicalTrials.gov identifier).

[Anterior cruciate ligament injury in adults : Diagnostics and treatment]

The anterior cruciate ligament (ACL) together with the posterior cruciate ligament is the central stabilizer of the knee. It stabilizes the tibia against increased anterior translation and internal rotation. With an incidence of 46/100,000 ACL tears are among the most common sports injuries in Germany. New prevention programs can reduce the risk of ACL injuries. Surgical treatment is recommended for young and athletic patients as it can also reduce the risk of further relevant injuries of the meniscus and cartilage. The standard of surgical treatment in Germany is the ACL reconstruction with an autologous tendon graft. In selected cases, the preservation of the ACL by arthroscopic refixation shows good results. Instead of the previously used purely time-based rehabilitation, function-based criteria are increasingly being included in the aftercare.

Clinical Outcomes and the Failure Rate of Revision Anterior Cruciate Ligament Reconstruction Were Comparable Between Patients Younger Than 40 Years and Patients Older Than 40 Years: A Minimum 2-Year Follow-Up Study

PURPOSE

To compare the clinical outcomes and failure rates of revision anterior cruciate ligament reconstruction (ACLR) between young and middle-aged surgery patients.

METHODS

Patients who underwent revision ACLRs between January 2008 and June 2017 with a minimum 2-year follow-up were retrospectively evaluated. Patients were divided into 2 groups according to age: ≥40 years (group A) and <40 years (group B). Detailed patient demographic data, preoperative radiographic data, and concurrent meniscal and chondral lesion were reviewed. Clinical scores, laxity tests results, and graft failures were compared between groups at the final follow-up.

RESULTS

Eighty-six patients (group A, n = 24, 46.6 ± 4.5 years; group B, n = 62, 26.2 ± 6.3 years) were included in this study. Demographic data showed that the time interval from primary to revision ACLR was longer in group A than in group B (96.2 ± 80.9 vs. 52.0 ± 42.1 months, P = .011). Group A had a higher prevalence of chondral defects of the trochlea (P = .016). No significant differences were identified in the prevalence and severity of meniscal lesions. At the final follow-up, all clinical scores were improved postoperatively but did not differ significantly between the groups. No significant differences were identified in side-to-side difference on Telos stress radiographs (group A, 6.3 ± 5.0 mm; group B, 5.6 ± 3.8 mm; P = .403) and graft failure rate (group A, 33.3%; group B, 30.6%; P = .358) at the final follow-up.

CONCLUSIONS

The current study showed that the clinical outcomes of revision ACLRs in patients improved significantly in patients younger than 40 years and were comparable to those observed in patients older than 40 years at a minimum 2-year follow-up.

LEVEL OF EVIDENCE

III.

A Review on Finite Element Modeling and Simulation of the Anterior Cruciate Ligament Reconstruction

The anterior cruciate ligament (ACL) constitutes one of the most important stabilizing tissues of the knee joint whose rapture is very prevalent. ACL reconstruction (ACLR) from a graft is a surgery which yields the best outcome. Taking into account the complicated nature of this operation and the high cost of experiments, finite element (FE) simulations can become a valuable tool for evaluating the surgery in a pre-clinical setting. The present study summarizes, for the first time, the current advancement in ACLR in both clinical and computational level. It also emphasizes on the material modeling and properties of the most popular grafts as well as modeling of different surgery techniques. It can be concluded that more effort is needed to be put toward more realistic simulation of the surgery, including also the use of two bundles for graft representation, graft pretension and artificial grafts. Furthermore, muscles and synovial fluid need to be included, while patellofemoral joint is an important bone that is rarely used. More realistic models are also required for soft tissues, as most articles used isotropic linear elastic models and springs. In summary, accurate and realistic FE analysis in conjunction with multidisciplinary collaboration could contribute to ACLR improvement provided that several important aspects are carefully considered.

Anatomic ACL reconstruction reduces risk of post-traumatic osteoarthritis: a systematic review with minimum 10-year follow-up

PURPOSE

To systematically review the literature for radiographic prevalence of osteoarthritis (OA) at a minimum of 10 years following anterior cruciate ligament (ACL) reconstruction (ACLR) with anatomic vs. non-anatomic techniques. It was hypothesized that the incidence of OA at long-term follow-up would be lower following anatomic compared to non-anatomic ACLR.

METHODS

A systematic review was performed by searching PubMed, MEDLINE, EMBASE, and the Cochrane Library, for studies reporting OA prevalence by radiographic classification scales at a minimum of 10 years following ACLR with autograft. Studies were categorized as anatomic if they met or exceeded a score of 8 according the Anatomic ACL Reconstruction Scoring Checklist (AARSC), while those with a score less than 8 were categorized as non-anatomic/non-specified. Secondary outcomes included graft failure and measures of knee stability (KT-1000, Pivot Shift) and functional outcomes [Lysholm, Tegner, subjective and objective International Knee Documentation Committee (IKDC) scores]. OA prevalence on all radiographic scales was recorded and adapted to a normalized scale.

RESULTS

Twenty-six studies were included, of which 5 achieved a score of 8 on the AARSC. Using a normalized OA classification scale, 87 of 375 patients (23.2%) had diagnosed OA at a mean follow-up of 15.3 years after anatomic ACLR and 744 of 1696 patients (43.9%) had OA at mean follow-up of 15.9 years after non-anatomic/non-specified ACLR. The AARSC scores were 9.2 ± 1.3 for anatomic ACLR and 5.1 ± 1.1 for non-anatomic/non-specified ACLR. Secondary outcomes were relatively similar between techniques but inconsistently reported.

CONCLUSIONS

This study showed that anatomic ACLR, defined as an AARSC score ≥ 8, was associated with lower OA prevalence at long-term follow-up. Additional studies reporting long-term outcomes following anatomic ACLR are needed, as high-level studies of anatomic ACLR are lacking. The AARSC is a valuable resource in performing and evaluating anatomic ACLR. Anatomic ACLR, as defined by the AARSC, may reduce the long-term risk of post-traumatic OA following ACL injury to a greater extent than non-anatomic ACLR.

LEVEL OF EVIDENCE

IV.

Graft Inclination Angles in Anterior Cruciate Ligament Reconstruction Vary Depending on Femoral Tunnel Reaming Method: Comparison Among Transtibial, Anteromedial Portal, and Outside-In Retrograde Drilling Techniques

PURPOSE

To compare graft coronal and sagittal inclination angles in anterior cruciate ligament (ACL) reconstruction performed by different femoral tunnel drilling techniques with respect to intact native ACL.

METHODS

In total, 72 patients were prospectively enrolled in the study. The inclusion criteria were complete ACL rupture and patient age between 18 and 55 years. Reconstructions were performed using 4 different femoral tunnel drilling technique: transtibial (TT), anteromedial portal with rigid (AMP-RR) or flexible (AMP-FR) reamer, and outside-in retrograde drilling (OI) techniques. Eighteen patients with intact native ACL were included as controls. Sagittal and coronal graft inclination angles were measured by magnetic resonance imaging 6 months after the procedure by 1 radiologist blinded in regards to the used technique.

RESULTS

OI and AMP-FR techniques allowed for the maintenance of native-like ACL inclination in both the sagittal and coronal planes, whereas TT and AMP-RR increased the sagittal angle by a mean of 9.5° (P < .001) and 6.7° (P = .003), respectively, compared with native ACLs. AMP-RR and TT also showed increased sagittal graft inclination compared with AMP-FR (+6.1°, P = .009 and +9.0°, P < .001, respectively) and OI-drilling techniques (+5.5°, P = .024 and +8.4°, P < .001, respectively). No differences were observed among study groups in terms of coronal graft inclination.

CONCLUSIONS

The study hypothesis was partially confirmed, since OI and AMP-FR techniques, but not AMP-RR, using an independent portal for femoral drilling produce a more anatomic graft inclination on the sagittal plane with respect to TT.

LEVEL OF EVIDENCE

II, prospective comparative study.

Anterior cruciate ligament repair versus reconstruction: A kinematic analysis

BACKGROUND

The purpose of this study was to compare the biomechanical properties of an anterior cruciate ligament (ACL) anatomic repair of a true femoral avulsion to an anatomic ACL reconstruction. It was hypothesized that the ACL repair and ACL reconstruction would have comparable biomechanical behavior when compared to the native knee.

METHODS

Ten paired fresh-frozen cadaveric knees (n = 20) were used to investigate knee kinematics when an anterior drawer force, varus, valgus, internal, and external rotational moment were applied at 0, 15, 30, 45, 60, and 90 degrees of flexion. Displacement and rotation were recorded in the following conditions: ACL-intact, ACL-deficient, and ACL-repaired vs reconstructed.

RESULTS

Sectioning of the ACL significantly increased anterior tibial translation (0°, 15°, 30° and 45°) compared to the intact state. The mean anterior displacement difference from intact was lower in the ACL-repaired knees compared to reconstructed knees at 30° and 90°. There were no significant differences between conditions in varus, valgus, internal, or external rotations.

CONCLUSION

ACL repair and ACL reconstruction procedures restored knee anterior tibial translation in matched paired specimens. There were no differences in valgus, varus, internal, or external rotation. Although, ACL-repaired knees (avulsion model) demonstrated less anterior tibial translation when compared to ACL-reconstructed knees, this difference was less than one millimeter. Based on the findings of this study, repair and reconstruction procedures both restored anterior tibial translation in matched-pair specimens. This suggests that the initial functionality of both techniques is similar and that further clinical studies are needed to compare the long-term stability.

Anteromedial Portal Double-Bundle Anterior Cruciate Ligament Reconstruction Yields Similar Outcomes to Non-AMP Femoral Drilling Double-Bundle Techniques: A Systematic Review of Comparative Studies

Background

Biomechanical studies have shown double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) to have increased anterior and rotational stability as compared with single-bundle ACLR. Various techniques exist to drill the femoral tunnel, such as anteromedial portal (AMP), outside-in (OI), and transtibial (TT) drilling. However, it is unclear whether one drilling technique is superior to others when a DB graft is used.

Purpose

To systematically assess the outcomes and complications in patients undergoing DB ACLR through an AMP technique as compared with other femoral drilling techniques.

Study Design

Systematic review; Level of evidence, 3.

Methods

PubMed, Medline, and EMBASE databases were searched in April 2018. Nonrandomized studies were assessed with the MINORS (Methodological Index for Nonrandomized Studies), whereas randomized studies were assessed with the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system.

Results

Ten studies comprising 722 patients satisfied the inclusion criteria. A total of 351 patients underwent DB ACLR with AMP drilling (mean ± SD age, 32.7 ± 4.7 years); 318 patients had DB ACLR with OI drilling (age, 31.9 ± 4.1 years); and 53 received a DB ACLR with TT drilling (age, 26.5 ± 2.0 years). Graft types used included hamstring autograft (74.1%; n = 247), tibialis anterior autograft (6.0%; n = 20) and unspecified grafts (19.8%; n = 66). No significant difference in postoperative Tegner and Lysholm scores was found between the AMP and OI groups postoperatively. The AMP group had a lower anterior and posterior graft bending angle as compared with the OI group. Four patients (1.1%) in the AMP group had graft reruptures, as compared with 9 reruptures (2.8%) in the OI group. There were no reports of rerupture in the TT group.

Conclusion

DB AMP ACLR results in significantly improved functional outcome scores postoperatively. AMP techniques yield similar functional outcomes to OI ACLR. No direct comparison in functional outcomes scores were available between the AMP and TT techniques. Low overall complication and revision rates were observed for patients undergoing DB AMP ACLR and were found to be similar to those of other femoral drilling techniques. Owing to a steeper graft bending angle in patients undergoing OI or TT ACLR relative to AMP ACLR, patients treated with OI or TT femoral drilling may have increased strain placed on the graft. Based on the various limitations in the available literature, it is not currently possible to make a definite conclusion of whether AMP is superior to non-AMP techniques in the setting of DB ACLR.

Failure risks in anatomic single-bundle anterior cruciate ligament reconstruction via the outside-in tunnel technique using a hamstring autograft

Purpose

To retrospectively evaluate the failure risk factors in anatomic single-bundle anterior cruciate ligament (ACL) reconstruction via outside-in tunnel technique using a hamstring autograft, and investigate the relationship between each risk factor.

Methods

The patients who underwent the ACL reconstruction with a minimum 1-year follow-up were included. We divided the patients into two groups - those who experienced graft failure (the failure group) and those who did not experience graft failure (the no failure group) - and compared their age, height, weight, sports activity level, graft size, and muscle strength. We defined graft failure as patients who underwent revision ACL reconstruction or had a second injurious ACL episode and those with a graft grade of C or D based on the International Knee Documentation Committee score.

Results

The study included 232 patients (101 male, 131 female; mean age at operation was 26.1 ± 11.9 years). The failure rate was 11.6% (failure group: 27 patients; no failure group: 205 patients). The patients in the failure group were younger and had higher sports activity level than those in the no failure group. (p < 0.001 and p < 0.001, respectively). Patient body weight in the failure group was lower than that in the no failure group (p = 0.047). Regarding the graft size of the tibial side, the failure group had smaller graft sizes than the no failure group (p = 0.030). With respect to muscle strength, quadriceps strength 6 months after surgery in the failure group was stronger than that in the no failure group (p = 0.001). In addition, the hamstring/quadriceps strength (H/Q) ratios 3 and 6 months after surgery were lower in the failure group than that in the no failure group (p = 0.041 and p = 0.001, respectively). There was an association between the age and the body weight, between the body weight and the graft size of the tibial side, and between lower age and high sports activity. Moreover, the high quadriceps strength at 6 months and the low H/Q ratio at 3 months were related to the low H/Q ratio at 6 months.

Conclusion

Young age, high activity sports level, low body weight, small graft diameter of the tibial side, high quadriceps strength at 6 months, and low H/Q ratio at 3 and 6 months can be failure risk factors in anatomic single-bundle ACL reconstruction via the outside-in tunnel technique using a hamstring autograft.

Femoral tunnel position in chronic anterior cruciate ligament rupture reconstruction: randomized controlled trial comparing anatomic, biomechanical and clinical outcomes

PURPOSE

The aim of this study was to compare the outcomes between anteromedial (AM) and transtibial (TT) femoral tunnel positioning techniques for the reconstruction of chronic anterior cruciate ligament (ACL) rupture.

MATERIALS AND METHODS

It is a randomized prospective study of 106 patients who underwent ACL reconstruction because of a chronic ACL rupture (55 AMT, 51 TT). Minimum follow-up was 2 years. Demographic, clinical and radiological data, including MRI grafts' anatomy and biomechanics intraoperative navigation system evaluation, were analyzed. Also, International Knee Documentation Committee score, Tegner Knee score, Lysholm Knee Score, Short-Form Health Survey and 4-point Likert Scale were evaluated.

RESULTS

The AM technique achieves a more anatomic graft than TT technique in both sagittal and coronal plane (6° approximately). Immediate postoperative biomechanical evaluation of the graft showed both techniques significantly improved translational and rotational laxity (p = 0.000). AMT showed superiority only in controlling internal rotation (p = 0.016). Both techniques reported significant improvement in all evaluated score scales, without differences between techniques. Independently of the femoral tunnel positioning technique, patients with cartilage lesion had worse clinical outcomes.

CONCLUSIONS

Our findings suggest that AMT achieves a more anatomical and biomechanically accurate graft allowing better control over internal rotation laxity; however, this does not lead to better clinical outcomes if we compare with TT in the reconstruction of chronic ACL rupture. Patients with chronic ACL rupture and cartilage lesion had worse clinical outcomes, independently the femoral tunnel positioning technique.

Greater magnitude tibiofemoral contact forces are associated with reduced prevalence of osteochondral pathologies 2-3 years following anterior cruciate ligament reconstruction

PURPOSE

External loading of osteoarthritic and healthy knees correlates with current and future osteochondral tissue state. These relationships have not been examined following anterior cruciate ligament reconstruction. We hypothesised greater magnitude tibiofemoral contact forces were related to increased prevalence of osteochondral pathologies, and these relationships were exacerbated by concomitant meniscal injury.

METHODS

This was a cross-sectional study of 100 individuals (29.7 ± 6.5 years, 78.1 ± 14.4 kg) examined 2-3 years following hamstring tendon anterior cruciate ligament reconstruction. Thirty-eight participants had concurrent meniscal pathology (30.6 ± 6.6 years, 83.3 ± 14.3 kg), which included treated and untreated meniscal injury, and 62 participants (29.8 ± 6.4 years, 74.9 ± 13.3 kg) were free of meniscal pathology. Magnetic resonance imaging of reconstructed knees was used to assess prevalence of tibiofemoral osteochondral pathologies (i.e., cartilage defects and bone marrow lesions). A calibrated electromyogram-driven neuromusculoskeletal model was used to predict medial and lateral tibiofemoral compartment contact forces from gait analysis data. Relationships between contact forces and osteochondral pathology prevalence were assessed using logistic regression models.

RESULTS

In patients with reconstructed knees free from meniscal pathology, greater medial contact forces were related to reduced prevalence of medial cartilage defects (odds ratio (OR) = 0.7, Wald χ²(2) = 7.9, 95% confidence interval (CI) = 0.50-95, p = 0.02) and medial bone marrow lesions (OR = 0.8, Wald χ²(2) = 4.2, 95% CI = 0.7-0.99, p = 0.04). No significant relationships were found in lateral compartments. In reconstructed knees with concurrent meniscal pathology, no relationships were found between contact forces and osteochondral pathologies.

CONCLUSIONS

In patients with reconstructed knees free from meniscal pathology, increased contact forces were associated with fewer cartilage defects and bone marrow lesions in medial, but not, lateral tibiofemoral compartments. No significant relationships were found between contact forces and osteochondral pathologies in reconstructed knees with meniscal pathology for any tibiofemoral compartment. Future studies should focus on determining longitudinal effects of contact forces and changes in osteochondral pathologies.

LEVEL OF EVIDENCE

IV.

Anteromedial Portal Drilling Yielded Better Survivorship of Anterior Cruciate Ligament Reconstructions When Comparing Recent Versus Early Surgeries With This Technique

PURPOSE

To compare anteromedial (AM) and transtibial (TT) femoral drilling hole techniques in primary anterior cruciate ligament reconstruction, using the Danish Knee Ligament Reconstruction Register, comparing revision rates and clinical outcomes from 2 time periods, 2007 to 2010 and 2012 to 2015.

METHODS

A total of 8,386 primary anterior cruciate ligament reconstructions were registered between January 2007 to December 2010 and 8,818 in the period January 2012 to December 2015. Revision ACL was the primary endpoint. Secondary endpoints were the objective and subjective clinical outcomes. Crude and adjusted relative risks (RRs) with 95% confidence interval (CIs) were calculated.

RESULTS

The adjusted RR for revision surgery in the AM (2007-10) group compared with the TT (2007-10) group was 1.45 (95% CI, 1.17-1.78; P < .05), but when comparing the AM (2012-15) group with TT (2012-15) group, the RR was 0.99 (95% CI, 0.68-1.45; P = .96). One-year postoperative objective stability testing showed an RR = 1.38 (95% CI, 1.19-1.60; P < .01) for rotational stability and an RR = 1.37 (95% CI, 0.99-1.89; P < .01) for sagittal stability when comparing AM (2007-10) to TT (2007-10). No significant difference in objective stability was found in the more recent period. Lastly, comparing the subjective scores, the AM (2012-15) had a significantly higher Tegner score 1 year postoperatively compared with the TT-group (2012-15).

CONCLUSIONS

This study found an increased RR of revision anterior cruciate ligament and rotational and sagittal instability 1 year postoperatively for the AM technique in the period from 2007 to 2010. However, there was no significant difference in revision surgery and objective measures between the techniques from 2012 to 2015. Nevertheless, a higher activity level was found in the AM group. The results could indicate that the results found in the period 2007 to 2010 may have been caused by a learning curve when introducing a new and more complex procedure (AM).

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Comparison of 2 femoral tunnel drilling techniques in anterior cruciate ligament reconstruction. A prospective randomized comparative study

BACKGROUND

To evaluate the length and position of femoral tunnel,and exam whether knee stability and clinical functional outcomes are superior in AMP method.

METHODS

From August 2014 to February 2015, we prospectively recruited 104 patients undergoing anterior cruciate ligament reconstruction. They were randomized to anteromedial portal or transtibial method. All patients underwent Lysholm score, International Knee Documentation Committee score,Tegner score at pre-operative and last follow-up point as subjective assessment of clinical function. The Lachman test, the Pivot-shift test and KT-1000 were performed at the last follow-up as a evaluation of knee joint stability. We measured the length of femoral tunnel intraoperatively and at 1 week post-operatively, CT-based three-dimensional reconstruction was used to assess femoral tunnel location.

RESULTS

The average follow-up time of anteromedial portal group was 25.7 ± 6.8 months (range:12-36.5 months), and the average follow-up time of the transtibial group was 24.9 ± 6.0 months (range:12-37 months). There was no significant difference between the groups pre-operative Lysholm score, IKDC score and Tegner scores. Both groups showed significantly improvement in these clinical function scores at follow up for their ACL reconstruction. However, there was no significant difference in the function scores between the two groups at last follow up. However, the mean femoral tunnel length in the anteromedial portal group was significantly shorter than that in the transtibial group. And tunnel location was significantly lower and deeper with the anteromedial portal technique than with the transtibial technique.

CONCLUSION

The use of anteromedial portal method resulted in a significantly lower and deeper placement of the femoral tunnel, and a shorter tunnel length compared to the transtibial method. However, there was no statistical difference in terms of clinical function and knee joint stability between the anteromedial portal method and the transtibial method.

TRIAL REGISTRATION

Name of the registry: Chinese Clinical Trial Registry. The registration number: ChiCTR1800014874 . The date of registration: 12 February, 2018. The study is retrospectively registered.

Editorial Commentary: Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction … Are We Barking up the Wrong Tree?

As techniques in anterior cruciate ligament reconstruction continue to evolve, studies comparing single bundle to double bundle continue to mount in numbers. Although there have been great strides in identifying anatomic tunnel placement, how many tunnels (bundles) are created, and how those tunnels are placed, we still seem to be stuck with grossly similar results with respect to both patient-related and objective outcome measures. It seems to me that we can do a very good job reproducing what we do to a cadaver in a lab. Unfortunately, that cadaver does not get up and walk after our job is done as surgeons. Nearly 20% of our athletes do not return to their prior level of sport, and 30% of our patients develop radiographic signs of osteoarthritis. There must be something we are neglecting.