Dynamic intraligamentary stabilization of anterior cruciate ligament repair: hardware removal has no effect on knee laxity at 2-year follow-up

Graft failure and revision rate after ACL repair with dynamic intraligamentary stabilization. One-year results of a prospective case series of 155 patients

PURPOSE

The aim of this study was to assess graft failure, revision rate, and functional outcomes after treatment of acute ACL rupture with dynamic intraligamentary stabilization (DIS) Ligamys device one year post surgery. Additionally, differences in functional outcome between patients with and without anteroposterior laxity were assessed. It was hypothesized that the failure rate of DIS was non-inferior to that of previously reported ACL reconstruction (10%).

METHODS

In this prospectively designed multicenter study, including patients with an acute ACL rupture, DIS was performed within 21 days after rupture. Primary outcome was failure of the graft at 1 year post surgery, defined as 1) re-rupture of the graft, 2) revision of DIS, or 3) a > 3 mm side-to-side difference in anterior tibial translation compared to the non-operated knee (∆ATT), measured by the KT1000 device. Additional analysis was performed using a 5 mm threshold. The subjective International Knee Documentation Committee Score (IKDC) and Numerical Rating Scales (NRS) for pain and confidence were used to evaluate functional outcome.

RESULTS

A total of 155 patients were included with a mean age at surgery of 27.8 years (SD 9.4). The mean interval from rupture to DIS was 16.4 days (SD 5.2). At a median follow-up of 13 months (IQR 12-18) the failure rate of the graft was 30.2% (95%CI:22.0-39.4); 11 patients (7%) required secondary reconstructive surgery and of the 105 patients who attended ATT measurement, 24 patients (23%) had an ∆ATT > 3 mm. Secondary analysis, based on a 5 mm threshold, revealed a failure rate of 22.4% (95%CI: 15.2; 31.1). A total of 39 patients (25%) reported at least one complication, comprising mainly arthrofibrosis, traumatic re-rupture and pain. In these patients, removal of the monoblock was performed in 21 cases (13.5%). At follow-up no significant differences in functional outcomes between patients with ∆ATT > 3 mm and stable ATT were observed.

CONCLUSION

This prospective multicenter study found a high failure rate at one year follow-up of 30% (7% revision surgery and 23% > 3 mm side-to-side difference in anterior tibial translation) in patients treated by primary repair of the ACL with DIS, and did therefore not demonstrate non-inferiority to ACL reconstruction. For patients who did not require secondary reconstructive surgery, this study found good functional outcomes, also in case of persistent anteroposterior knee laxity (∆ATT > 3 mm).

LEVEL OF EVIDENCE

Level IV.

Clinical outcomes in dynamic intraligamentary stabilization technique for anterior cruciate ligament tear: A meta-analysis

BACKGROUND

To compare the clinical outcome between dynamic intraligamentary stabilization (DIS) and anterior cruciate ligament (ACL) reconstruction in ACL tears.

METHODS

PubMed, the Cochrane Library, and Embase databases were searched to identify published articles on clinical studies comparing DIS versus ACL reconstruction. The results of the eligible studies were analyzed in terms of anteroposterior knee laxity translation (ΔATT) between the injured and contralateral knees, and subjective International Knee Documentation Committee (IKDC), Lysholm score, Tegner score, and ipsilateral ACL failure, implant removal, and ACL revision.

RESULTS

Five clinical studies including 429 patients with ACL tears met the inclusion criteria. DIS showed statistically comparable outcomes of ΔATT (P = .12), IKDC (P = .38), Tegner (P = .82), ACL failure (P = .50), ACL revision (P = .29) with ACL reconstruction. A significantly higher rate of implant removal (odds ratio for DIS vs ACL reconstruction, 7.73; 95% confidence interval [CI], 2.72-22.00; P = .0001) but statistically higher Lysholm score (mean difference between DIS and ACL reconstruction, 1.59; 95% CI, 0.24-2.93; P = .02) were found in DIS group.

CONCLUSION

Five clinical studies including 429 patients with ACL tears met the inclusion criteria. DIS showed statistically comparable outcomes of ΔATT (P = .12), IKDC (P = .38), Tegner (P = .82), ACL failure (P = .50), ACL revision (P = .29) with ACL reconstruction. A significantly higher rate of implant removal (odds ratio for DIS vs ACL reconstruction, 7.73; 95% CI, 2.72-22.00; P = .0001) but statistically higher Lysholm score (mean difference between DIS and ACL reconstruction, 1.59; 95% CI, 0.24-2.93; P = .02) were found in DIS group.

Biological enhancement methods may be a viable option for ACL arthroscopic primary repair - A systematic review

BACKGROUND

Bioactive factors combined with advanced anterior cruciate ligament (ACL) primary repair technology have been used to treat ACL repairs. The current review was conducted to identify whether biological enhancement could enable superior clinical outcome, including side-to-side difference, failure rate, reoperation rate and subjective scores.

HYPOTHESIS

The implementation of ACL primary repair with biological enhancement will provide better clinical outcomes in terms of side-to-side differences, failure rate, reoperation rate and subjective scores than ACL primary repair alone.

MATERIALS AND METHODS

A systematic literature review was performed following PRISMA guidelines by searching all studies reporting outcomes of arthroscopic primary repair with or without biological augmentation published until April 19, 2020, in Medline, PubMed, Embase and the Cochrane Library. Primary metrics were side-to-side differences, failure rate and reoperation rate, as well as measurements of patient-reported outcomes at the last follow-up.

RESULTS

A total of 20 studies were finally included in this work, of which 3 were Grade I (15%), 3 studies were Grade III (15%), and 14 studies were Grade IV (70%) in terms of the level of evidence. There were 729 patients with a mean age of 30 (range: 8-68) years, and the mean follow-up period of which was 38 (range: 3-122) months. At the final follow-up, the postoperative side-to-side differences (the proportion of patients with a side-to-side difference less than 3mm) and patient-report outcomes were significantly better in the biological enhancement group. Nevertheless, there were no significant differences between the two groups in the rate of surgical failure, the rate of revision, or the positive Lachman test or pivot shift test.

CONCLUSION

Biologically enhanced arthroscopic ACL primary repair was superior to ACL primary repair alone in terms of postoperative side-to-side differences (proportion of patients with a side-to-side difference less than 3mm) and patient-reported outcomes. Thus, biologically enhanced arthroscopic ACL primary repair can be preferentially recommended over ACL arthroscopic primary repair alone.

LEVEL OF EVIDENCE

IV, systematic review.

Primary stability of single-stage revision reconstruction of the anterior cruciate ligament in case of failure of dynamic intraligamentary stabilization depends on implant position during ACL repair

INTRODUCTION

The object of this study was to evaluate the primary stability of tibial interference screw (IFS) fixation in single-stage revision surgery of the anterior cruciate ligament (ACL) in the case of recurrent instability after ACL repair with dynamic intraligamentary stabilization (DIS), dependent on the implant position during DIS.

MATERIALS AND METHODS

Tibial aperture fixation in ACL reconstruction (ACL-R) was performed in a porcine knee model using an IFS. Native ACL-R was performed in the control group (n = 15). In the intervention groups DIS and subsequent implant removal were performed prior to single-stage revision ACL-R. A distance of 20 mm in group R-DIS1 (n = 15) and 5 mm in group R-DIS2 (n = 15) was left between the joint line and the implant during DIS. Specimens were mounted in a material-testing machine and load-to-failure was applied in a worst-case-scenario.

RESULTS

Load to failure was 454 ± 111 N in the R-DIS1 group, 154 ± 71 N in the R-DIS2 group and 405 ± 105 N in the primary ACL-R group. Load-to-failure, stiffness and elongation of the group R-DIS2 were significantly inferior in comparison to R-DIS1 and ACL-R respectively (p < 0.001). No significant difference was found between load-to-failure, stiffness and elongation of R-DIS1 and the control group.

CONCLUSION

Primary stability of tibial aperture fixation in single-stage revision ACL-R in case of recurrent instability after DIS depends on monobloc position during ACL repair. Primary stability is comparable to aperture fixation in primary ACL-R, if a bone stock of 20 mm is left between the monobloc and the tibial joint line during the initial procedure.

Primary Repair of Anterior Cruciate Ligament Injuries: Current Level of Evidence of Available Techniques

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Recently, there has been a resurgence of interest in primary anterior cruciate ligament (ACL) repair that has the potential to preserve native tissue using a more minimally invasive approach. Multiple repair techniques for different tear types have been reported over the last decade.

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From a healing perspective, proximal tears can be reapproximated directly to the femoral wall because they have better intrinsic healing capacity than midsubstance tears. These procedures can be classified further as direct suture repair with or without static or dynamic augmentation. Current evidence does not support direct repair of midsubstance tears because of their limited healing capacity. In many instances, biological augmentation is needed to enhance the healing potential of the ACL.

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While ACL repair is certainly not an effective surgical approach for all tears or in all patients, this procedure can be an effective and less morbid alternative to ACL reconstruction in carefully selected patients.

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The overall current reported level of evidence of published studies has ranged from low to moderate, and thus there is a need for higher-quality, comparative studies in which outcomes of larger patient groups are compared with the current gold standard of ACL reconstruction.

Standard MRI May Not Predict Specific Acute Anterior Cruciate Ligament Rupture Characteristics

Background

There has been renewed interest in the concept of anterior cruciate ligament (ACL) suture repair (ACLSR). Morphologic characteristics of the ruptured ACL remnant play a role in deciding whether a patient is eligible for ACLSR. However, no classification of these characteristics of ACL rupture on magnetic resonance imaging (MRI) scans has yet been compared with intraoperative findings in the context of ACLSR.

Purpose

To investigate the value of using preoperative MRI to predict specific characteristics of acute complete ACL rupture.

Study Design

Cohort study (diagnostic); Level of evidence, 2.

Methods

A total of 25 patients were included. Two radiologists classified ACL rupture location and pattern on preoperative 1.5-T MRI scans with a standard sequence; the results were compared with the corresponding findings at arthroscopy conducted by a single surgeon. The agreement between the MRI and surgical findings was calculated using Cohen κ values. Furthermore, the reliability coefficients of the MRI classifications within and between radiologists were calculated.

Results

The agreement between MRI classification and arthroscopic findings for ACL rupture location was slight (Cohen κ, 0.016 [radiologist 1] and 0.087 [radiologist 2]), and for ACL rupture pattern, this was poor to slight (Cohen κ, <0 and 0.074). The intraobserver reliability of MRI classification for ACL rupture location was moderate for radiologist 1 and slight for radiologist 2 (Cohen κ, 0.526 and 0.061, respectively), and for ACL rupture pattern, this was slight for radiologist 1 and 2 (Cohen κ, 0.051 and 0.093, respectively). The interobserver reliability of MRI classification for ACL rupture location and pattern was slight between radiologists (Cohen κ, 0.172 and 0.040, respectively).

Conclusion

In the current study, we found poor to slight agreement between MRI classification and arthroscopic findings of specific ACL rupture characteristics. In addition, the intra- and interobserver reliability for MRI classification of the ACL rupture characteristics was slight to moderate.

Efficacy of Nonaugmented, Static Augmented, and Dynamic Augmented Suture Repair of the Ruptured Anterior Cruciate Ligament: A Systematic Review of the Literature

BACKGROUND

Anterior cruciate ligament suture repair (ACLSR) was abandoned late last century in favor of anterior cruciate ligament (ACL) reconstruction (ACLR) because of overall disappointing results. However, in recent years there has been renewed and increasing interest in ACLSR for treatment of ACL ruptures. Several contemporary ACLSR techniques are being used, but any difference in effectiveness is unclear.

HYPOTHESIS

Contemporary nonaugmented (NA), static augmented (SA), and dynamic augmented (DA) ACLSR leads to (1) comparable outcomes overall and (2) comparable outcomes between proximal third, middle third, and combined ACL rupture locations (a) within and (b) between ACLSR technique categories.

STUDY DESIGN

Systematic review.

METHODS

An electronic search was performed in the MEDLINE and Embase databases for the period between January 1, 2010, and August 7, 2019. All articles describing clinical and patient-reported outcomes for ACLSR were identified and included, and outcomes for NA, SA, and DA ACLSR categories were compared.

RESULTS

A total of 31 articles and 2422 patients were included. The majority of articles (65%) and patients (89%) reported outcomes of DA ACLSR. Overall, there was high heterogeneity in study characteristics and level as well as quality of evidence (19 level 4; 7 level 3; 3 level 2; and 2 level 1). Most studies indicated excellent patient-reported outcomes. Overall, the variability in (and the maximum of) the reported failure rate was high within all ACLSR categories. The variability in (and the maximum of) the reported rate of all other complications was highest for DA ACLSR. Regarding ACL rupture location, the failure rate was highest in proximal ACL ruptures within the SA and DA ACLSR categories; rates of all other reported complications were highest in combined ACL ruptures within the DA ACLSR category. However, no studies in the NA category and only 1 study in the SA ACLSR category evaluated combined ACL ruptures. The majority of studies comparing ACLSR and ACLR found no differences in outcomes.

CONCLUSION

The amount of high-quality evidence for contemporary ACLSR is poor. This makes it difficult to interpret differences among ACLSR categories and among ACL rupture locations and, though promising, to establish the role of ACLSR in the treatment of ACL ruptures. More high-quality large randomized clinical trials with longer follow-up comparing ACLSR and ACLR are needed.