The Influence of Anterior Cruciate Ligament Remnant on Postoperative Clinical Results in Patients with Remnant Preserving Anterior Cruciate Ligament Reconstruction

Anterior Cruciate Ligament Hybrid Remnant Preservation Reconstruction Demonstrates Equivalent Patient-Reported Outcomes and Complications as Traditional Anterior Cruciate Ligament Reconstruction After 1 Year

Purpose

To compare the outcomes of anterior cruciate ligament (ACL) Hybrid Remnant Preservation Reconstruction (HRPR) with traditional anterior cruciate ligament reconstruction (ACLR) and determine differences in patient-reported outcomes, range of motion (ROM), and complications after 12 months.

Methods

A retrospective cohort study of patients undergoing ACLR by a single surgeon from December 2020 to January 2022 was conducted. Patients undergoing ACL-HRPR were compared with control patients undergoing traditional ACLR with bone-patellar tendon-bone autograft. Preoperative and postoperative Patient-Reported Outcome Measurement Information System scores, International Knee Documentation Committee, and patient acceptable symptom state were recorded over 12 months. Any complications occurring 12 months postoperatively were collected.

Results

The final analysis included 104 patients, with 39 undergoing ACL-HRPR compared with 65 ACLR controls. Patients who received HRPR were on average 19.46 ± 5.01 years old, with 51.28% being female, whereas control patients were, on average, 21.92 ± 7.71 years old with 50.77% being female. Total ROM was equivalent between groups, with complete terminal extension at 12 months. No significant differences were found for patient acceptable symptom state; Patient-Reported Outcome Measurement Information System-Physical Function, -Pain Interference, or -Depression; or International Knee Documentation Committee at 6 months and 12 months postoperatively. Total ROM was similar between the HRPR and control groups. No differences were found for timed 6-meter hop test, hop for distance, or KT-1000 side-to-side differences. Over the 12-month period, complication rates were similar between groups (10% vs 12% P = .75) were similar.

Conclusions

ACL HRPR is associated with equivalent patient-reported outcomes, full ROM, and no differences in complications rates after 1 year compared with control patients in the present retrospective study.

Level of Evidence

Level III, retrospective cohort study.

The effects of remnant-preserving anterior cruciate ligament reconstruction on proprioception: A prospective comparative study

OBJECTIVE

The aim of this study was to investigate the effects of anterior cruciate ligament reconstruction performed by preserving remnant tissue on proprioception and to assess the effects it has on isokinetic quadriceps and hamstring muscle strength, as well as on range of motion and functional scores.

METHODS

A prospective study was conducted with 44 patients who underwent either anterior cruciate ligament reconstruction with remnant preservation (study group, n=22) or with remnant excision (control group, n=22) with the use of a 4-strand hamstring allograft. The mean follow-up time was 20.2 ± 1.4 months after surgery. Using an isokinetic dynamometer, proprioception was evaluated with passive joint position perception at 150, 450, and 600, and quadriceps femoris, and hamstring muscle strength were evaluated at speeds of 900, 1800, and 2400 per second. Range of motion was measured using a goniometer. Functional outcomes were assessed using International Knee Documentation Committee subjective knee evaluation score and Lysholm knee scoring questionnaires.

RESULTS

It was only at 15° of knee flexion that there was a statistically significant difference in proprioception; the median of the difference in the amount of deviation from the target angle between the healthy knee and the operated side was 1.7 (range, 0.7-20.7) in those with remnant preserved, and 2.7 (range, 1-26) in those with remnant excised (P=.016). At 2400/s speed, the mean quadriceps femoris strength was 77.2 ± 24.3 Nm in those with remnant preserved and 67.6 ± 24.2 Nm in those with remnant excised. (P=.048) There was no difference between the 2 groups in terms of range of motion, International Knee Documentation Committee, and Lysholm knee scoring. (P > .05) Conclusion: The present study has demonstrated that better proprioception and higher quadriceps femoris muscle strength can be obtained by remnant-preserving anatomical single-bundle anterior cruciate ligament reconstruction using a hamstring autograft.

LEVEL OF EVIDENCE

Level II, Therapeutic study.

Remnant preservation may improve proprioception after anterior cruciate ligament reconstruction

Aim

Our aim was to evaluate the literature investigating proprioception improvement after anterior cruciate ligament reconstruction (ACLR) and test the hypothesis that ACL tibial remnant-preserving reconstruction (ACLR-R) is more beneficial than standard technique (ACLR-S) in terms of postoperative proprioceptive function with various reported tests, including joint position sense (JPS) and threshold to detect passive motion (TTDPM).

Methods

An online search was performed in Embase, MEDLINE/PubMed, Cochrane, SPORTDiscus, and Web of Science databases before 5 October 2020, on the basis of the guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Key terms [(‘ACLR’ or ‘ACL-R’ or ‘anterior cruciate ligament reconstruction’) AND (‘remnant’ or ‘stump’) AND (‘proprioception’ or ‘proprioceptive’)] were used. The Oxford Centre for Evidence-Based Medicine and The McMaster Critical Review Form for Quantitative Studies were used for quality assessment. In total, four articles comparing proprioceptive functions between ACLR-R and ACLR-S were included, two of which were randomized clinical trials rated as level of evidence II, and two were retrospective cohort studies rated as level of evidence III. The outcomes were then compared. Evaluation of proprioception involved joint position sense (JPS) [reproduction of active positioning (RAP) and reproduction of passive positioning (RPP)] and threshold to detect passive motion (TTDPM) tests.

Results

Only four studies were included, with a total of 234 patients (119 ACLR-R patients and 115 ACLR-S patients). High heterogeneity in characteristics and outcome measurements was observed among the studies. Three studies performed sparing technique, and one performed tensioning technique. One study tested RAP and reported better results at an average of 7 months follow-up in ACLR-R (P < 0.05). Three studies tested RPP, one of which measured RPP within 12 months after surgery and reported better results in ACLR-R than in ACLR-S (P < 0.05). The other two studies reported similar results; however, the findings of one study were statistically insignificant. TTDPM was tested in one study, with no statistically significant difference found.

Conclusion

The current literature, although limited, reported proprioception improvement after ACLR-R (compared with ACLR-S) in terms of JPS. However, owing to the heterogeneity of the relevant studies, further research is required to determine remnant preservation effect on knee proprioceptive restoration.

Level of evidence

Level III, systematic review of Level II and III studies.

Properties of Knee Joint Position Sense Tests for Anterior Cruciate Ligament Injury: A Systematic Review and Meta-analysis

Background:

Knee proprioception is believed to be deficient after anterior cruciate ligament (ACL) injury. Tests of joint position sense (JPS) are commonly used to assess knee proprioception, but their psychometric properties (PMPs) are largely unknown.

Purpose:

To evaluate the PMPs (reliability, validity, and responsiveness) of existing knee JPS tests targeting individuals with ACL injury.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

PubMed, Allied and Complementary Medicine, CINAHL, SPORTDiscus, Web of Science, Scopus, CENTRAL, and ProQuest databases were searched to identify studies that assessed PMPs of knee JPS tests in individuals with ACL injury. The risk of bias for each included study was assessed and rated at the outcome level for each knee JPS test. Overall quality and levels of evidence for each PMP were rated according to established criteria. Meta-analyses with mean differences were conducted using random effects models when adequate data were available.

Results:

Included were 80 studies covering 119 versions of knee JPS tests. Meta-analyses indicated sufficient quality for known-groups and discriminative validity (ACL-injured knees vs knees of asymptomatic controls and contralateral noninjured knees, respectively), owing to significantly greater absolute errors for ACL-injured knees based on a strong level of evidence. A meta-analysis showed insufficient quality for responsiveness, which was attributed to a lack of significant change over time after diverse interventions with a moderate level of evidence. Statistical heterogeneity (I² > 40%) was evident in the majority of meta-analyses. All remaining PMPs (reliability, measurement error, criterion validity, convergent validity, and other PMPs related to responsiveness) were assessed qualitatively, and they failed to achieve a sufficient quality rating. This was a result of either the study outcomes not agreeing with the statistical cutoff values/hypotheses or the level of evidence being rated as conflicting/unknown or based on only a single study.

Conclusion:

Knee JPS tests appear to have sufficient validity in differentiating ACL-injured knees from asymptomatic knees. Further evidence of high methodologic quality is required to ascertain the reliability, responsiveness, and other types of validity assessed here. We recommend investigations that compare the modifiable methodologic components of knee JPS tests on their PMPs to develop standardized evidence-based tests.

Preservation of the Tibial Stump During Anterior Cruciate Ligament Reconstruction Surgery Did Not Increase the Rate of Surgery for Symptomatic Cyclops Lesions

Background

Preservation of the tibial stump during anterior cruciate ligament reconstruction (ACLR) is controversial. While proposed benefits include enhanced graft revascularization, improved proprioception, and decreased graft rupture rates, a potential complication is the development of a symptomatic cyclops lesion. It is therefore important to determine whether any benefits outweigh potential complications.

Purpose

To determine whether greater preservation of the tibial stump remnant would be associated with a decreased graft rupture rate without a concomitant increase in the rate of surgery for symptomatic cyclops lesions at 2 years after ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

A cohort of 658 patients in whom the amount of tibial stump preserved was classified as no stump (n = 228), <50% (n = 342), or >50% (n = 88) was followed up for 2 years, with graft ruptures and surgical treatment for cyclops lesions recorded. Contingency and Kaplan-Meier survival analyses were used to determine trends among the 3 remnant preservation groups in terms of graft rupture rates and surgery for cyclops lesions. Subgroup analysis was also conducted to examine sex-based differences.

Results

There was no significant association between graft rupture rates and remnant preservation. There was a significant trend for fewer operations for symptomatic cyclops lesions with greater remnant preservation when the entire cohort was analyzed (P = .04) and also when only female patients were analyzed (P = .04).

Conclusion

Although preservation of the tibial stump remnant was not associated with a reduced graft rupture rate, it was also not associated with increased rates of surgery for symptomatic cyclops lesions.

Anterior cruciate ligament reconstruction with remnant preservation: current concepts

Anterior cruciate ligament (ACL) tears are a common knee injury, and anatomic ACL reconstruction (ACLR) is now the standard of care to restore knee stability. Nevertheless, re-tear rates exceeding 5% are commonly reported, with an even higher percentage of patients unable to achieve preinjury knee function. As the torn ACL remnant contains elements (eg, cells, blood vessels and mechanoreceptors) essential to ACL function, it has been hypothesised that ACLR with remnant preservation may improve graft remodelling, in turn more quickly and completely restoring ACL structure and function. In this Current Concepts review, we summarise the present understanding of ACLR with remnant preservation, which includes selective bundle reconstruction of partial (one-bundle) ACL tears and single- and double-bundle ACLR with minimal to partial debridement of the torn ACL stump. Reported benefits of remnant preservation include accelerated graft revascularisation and remodelling, improved proprioception, decreased bone tunnel enlargement, individualised anatomic bone tunnel placement, improved objective knee stability and early mechanical support (with selective bundle reconstruction) to healing tissues. However, clinical studies of ACLR with remnant preservation are heterogeneous in the description of remnant characteristics and surgical technique. Presently, there is insufficient evidence to support the superiority of ACLR with remnant preservation over the standard technique. Future studies should better describe the ACL tear pattern, remnant volume, remnant quality and surgical technique. Progress made in understanding and applying remnant preservation may inform, and be reciprocally guided by, ongoing research on ACL repair. The goal of research on ACLR with remnant preservation is not only to achieve anatomic structural restoration of the ACL but also to facilitate biologic healing and regeneration to ensure a more robust and functional graft.

Remnant preservation technique versus standard technique for anterior cruciate ligament reconstruction: a meta-analysis of randomized controlled trials

Background

This meta-analysis was performed to compare the clinical outcomes of primary anterior cruciate ligament (ACL) reconstruction using the ACL remnant preservation technique versus the standard technique.

Methods

PubMed, Embase, and the Cochrane Library were searched through December 24, 2017, to identify randomized controlled studies that compared the use of the ACL remnant preservation technique versus the standard technique for primary ACL reconstruction. Statistical heterogeneity among the trials was evaluated with chi-square and I-square tests. A sensitivity analysis was conducted to explore sources of heterogeneity. Subgroup analysis was performed to identify potential differences according to type of ACL remnant tissue (remnant bundle or remnant fibers).

Results

Seven studies with a combined 412 patients (208 in the remnant preservation technique group and 204 in the standard technique group) were included in the meta-analysis. There was a significant difference between the groups in Lysholm score (mean difference (MD), 2.20; 95% confidence interval (CI), 0.95–3.45; P = 0.0006) and side-to-side difference (MD, − 0.71; 95% CI, − 0.87 to − 0.55; P < 0.01). There was no significant difference between the groups in subjective International Knee Documentation Committee (IKDC) score, complications, pivot shift test, Lachman test, or overall IKDC score. Subgroup analysis demonstrated that for primary ACL reconstruction with preservation of remnant fibers, the remnant preservation technique was superior to the standard technique based on Lysholm scores (P < 0.01) and side-to-side difference (P < 0.01).

Conclusions

Based on the current literature, using the remnant preservation technique showed a better clinical outcome than using the standard technique for patients undergoing primary ACL reconstruction with respect to Lysholm score and side-to-side difference. However, it remains unclear that there is a definite advantage to use the remnant preservation technique compared with the standard technique.

Electronic supplementary material

The online version of this article (10.1186/s13018-018-0937-4) contains supplementary material, which is available to authorized users.

A Narrative Review of Four Different New Techniques in Primary Anterior Cruciate Ligament Repair: "Back to the Future" or Another Trend?

Recently, four different operative techniques, referring to the primary anterior cruciate ligament (ACL) repair, were described. These are the dynamic intraligamentary stabilization (DIS) with Ligamys™, the Bridge-enhanced repair (BEAR), the use of internal brace, and the refixation with suture anchors. The purpose of this study was to assess the already-published, clinical, and pre-clinical results of those techniques. A literature review was conducted and implemented by three independent researchers. Inclusion criteria were clinical or cadaveric or animal studies about patients suffering from ACL rupture, who were treated with one of those four different arthroscopic techniques of primary ACL repair. There were 10 clinical trials dealing with the different techniques of primary ACL repair and 12 cadaveric or animal studies. The majority of the published clinical trials investigated the dynamic intraligamentary stabilization (DIS), while only four studies referred to the three other surgical techniques. Most of the clinical trials suggested that primary ACL repair should be done during the first 14–21 days after a proximal ACL rupture and not later. Further clinical evidence is needed for the techniques of bridge-enhanced ACL repair, internal brace, and suture anchors ACL refixation in order to support the animal and cadaveric biomechanical studies. Till now, the existing clinical trials were not enough to establish the use of those techniques in the ACL-ruptured patients. On the contrary, the Dynamic intraligamentary stabilization with Ligamys™ device demonstrated very promising results in different types of clinical studies.

Anterior cruciate ligament repair - past, present and future

Background

This article provides a detailed narrative review on the history and current concepts surrounding ligamentous repair techniques in athletic patients. In particular, we will focus on the anterior cruciate ligament (ACL) as a case study in ligament injury and ligamentous repair techniques. PubMed (MEDLINE), EMBASE and Cochrane Library databases for papers relating to primary anterior cruciate ligament reconstruction were searched by all participating authors. All relevant historical papers were included for analysis. Additional searches of the same databases were made for papers relating to biological enhancement of ligament healing.

Current standard

The poor capacity of the ACL to heal is one of the main reasons why the current gold standard surgical treatment for an ACL injury in an athletic patient is ACL reconstruction with autograft from either the hamstrings or patella tendon. It is hypothesised that by preserving and repairing native tissues and negating the need for autograft that primary ACL repair may represent a key step change in the treatment of ACL injuries.

History of primary ACL repair

The history of primary ACL repair will be discussed and the circumstances that led to the near-abandonment of primary ACL repair techniques will be reviewed.

New primary repair techniques

There has been a recent resurgence in interest with regards to primary ACL repair. Improvements in imaging now allow for identification of tear location, with femoral-sided injuries, being more suitable for repair. We will discuss in details strategies for improving the mechanical and biological environment in order to allow primary healing to occur.

In particular, we will explain mechanical supplementation such as Internal Brace Ligament Augmentation and Dynamic Intraligamentary Stabilisation techniques. These are novel techniques that aim to protect the primary repair by providing a stabilising construct that connects the femur and the tibia, thus bridging the repair.

Bio enhanced repair

In addition, biological supplementation is being investigated as an adjunct and we will review the current literature with regards to bio-enhancement in the form platelet rich plasma, bio-scaffolds and stem cells. On the basis of current evidence, there appears to be a role for bio-enhancement, however, this is not yet translated into clinical practice.

Conclusions

Several promising avenues of further research now exist in the form of mechanical and biological augmentation techniques. Further work is clearly needed but there is renewed interest and focus for primary ACL repair that may yet prove the new frontier in ligament repair.