Is Remnant Preservation in Anterior Cruciate Ligament Reconstruction Superior to the Standard Technique? A Systematic Review and Meta-Analysis

A study regarding the anterior cruciate ligament remnant: Differences in balance and postural control between remnant-preserving and remnant-non-preserving patients

INTRODUCTION

The anterior cruciate ligament (ACL) is the most frequently injured ligament of the knee. However, quantitative studies on evaluate the postural control influence resulted from the ACL remnant preservation or not are scarce. The aim of this study is to evaluate the postural control of patients submitted to ACL reconstruction with and without preservation of the injured remnant in pre and postoperative periods.

METHODS

Eighteen patients underwent ACL reconstruction and separated into 2 groups according to the preservation or not of the remnant: (I) submitted to ACL reconstruction with preservation of the remnant (10 patients); (II) submitted to ACL reconstruction without preservation of the remnant (8 patients). They were assessed using the Lysholm score and force plate, which evaluated the patient's postural stability for remnant and non-remnant preservation in ACL reconstruction surgery.

RESULTS

Group I showed statistically significant subjective and objective improvements, both at 3 and 6 months. Additionally, improvement of the Lysholm test at 6 months in Group II was also statistically significant. Furthermore, the results of the Friedman test for the VCOP and VY variables of Group I, with support of the injured side in the force plate, showed a statistically significant difference both for pre and postoperative period at 3 months, compared to the 6-month postoperative period. The variables EAC and VX were statistically different for Group II, considering the preoperative period, 3 and 6 months postoperatively.

CONCLUSION

Preserving the ACL remnant in patients with ACL injuries has a positive impact on postural stability during recovery.

Remnant-Sparing Anterior Cruciate Ligament Reconstruction Results in Similar Clinical, Functional, and Quality-of-Life Outcomes to Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Purpose

To compare a large cohort of patients who underwent remnant-sparing anterior cruciate ligament reconstruction (rACLR) with a matched group of patients who underwent anatomic single-bundle anterior cruciate ligament reconstruction (ACLR) with respect to clinical laxity, patient-reported outcomes, and functional testing.

Methods

Patients who underwent rACLR between January 2010 and December 2015 were matched according to age, sex, body mass index, and graft type to patients who underwent ACLR. The primary outcome measure was the ACL Quality of Life (ACL-QOL) score at final follow-up of 24 months. Secondary outcomes included functional tests and clinical laxity measurements at 6, 12, and 24 months postoperatively. Concurrent intra-articular pathology at the time of surgery and postoperative complications were also recorded. Statistical analyses included the dependent t test and the Wilcoxon signed rank test.

Results

A total of 210 rACLR patients were successfully matched to a corresponding cohort of 210 ACLR patients. There were no statistically significant differences in ACL Quality of Life (ACL-QOL) or functional testing results between the groups; however, scores in both groups showed a steady and statistically significant improvement over time. A statistically significant difference was noted with respect to the Lachman test findings, favoring the rACLR cohort (Z = -2.79, P = .005); no between-group difference was seen for the pivot-shift test (Z = -0.36, P = .72). The rACLR group had a significantly lower rate of concurrent meniscal and chondral injury. There was no difference in complications between the groups (Z = -0.49, P = .63).

Conclusions

There was no difference in patient-reported or functional testing outcomes in patients undergoing remnant-sparing compared with anatomic single-bundle ACLR. There was, however, a significantly lower rate of positive Lachman test findings after rACLR. Furthermore, the rate of concurrent meniscal and chondral pathology was lower in the rACLR group.

Level of Evidence

Level III, retrospective cohort study.

Comparative efficacy and safety of different surgical approaches for the treatment of anterior cruciate ligament injury: a Bayesian network meta-analysis protocol

INTRODUCTION

Anterior cruciate ligament (ACL) rupture can be treated surgically or non-surgically, with several surgical interventions available at present. However, the comparatively effective surgical intervention with relatively fewer side effects remains unknown. This study aims to fill in this gap by conducting a Bayesian network meta-analysis (NMA) and provide a theoretical basis for the clinical application.

METHOD AND ANALYSIS

We will perform a Bayesian NMA and will include randomised controlled trials (RCTs) published in English or Chinese that compare surgical intervention (ie, standard ACL reconstruction, ACL remnant-preserving reconstruction and ACL repair with suture augmentation to conservative therapy or studies that compare one surgical intervention to another for the symptom relief and function recovery of patients with ACL rupture. Primary outcome will be the proportion of patients with symptomatic and functional improvement measured by the Knee Injury and Osteoarthritis Outcome Score before and 6 months after treatment, with scores ranging from 0 (worst) to 100 (best). Secondary outcomes will be knee-specific quality of life (ACL QoL), return to activity and level of sport participation (Tegner or modified Tegner score), health-related QoL (EuroQol Group 5-Dimension 5-Level, EQ-5D-5L), resource use, intervention-related complications and patient satisfaction. We have developed search strategies for PubMed, Embase, the Cochrane Library and Web of Science, retrieving RCTs that meet the inclusion criteria from database inception to 1 December 2023. The methodological quality of the included RCTs will be assessed based on the Cochrane risk of bias table. The relative ranking probability of the best intervention will be estimated using the surface under the cumulative ranking curve. The Bayesian NMA will be conducted by using WinBUGS V.1.4.3. The Grading of Recommendations Assessment, Development and Evaluation approach will be applied to determine our confidence in an overall treatment ranking from the NMA.

ETHICS AND DISSEMINATION

Ethical approval for this study is not required because no private or confidential patient data will be used in this study. Findings of this study would be disseminated through the publication in a peer-reviewed medical journal.

PROSPERO REGISTRATION NUMBER

CRD42023437115.

A Technique for Hamstring Donor-Site Injection With Anesthetic Cocktail in Remnant-Preserving Anterior Cruciate Ligament Reconstruction

Arthroscopic anterior cruciate ligament reconstruction is a common procedure that requires effective postoperative pain management for successful rehabilitation. Opioids are traditionally used for pain relief, but their side effects decrease their widespread use. Local anesthesia techniques have gained interest as an alternative to opioids. This Technical Note discusses the use of an anesthetic cocktail for pain relief at the hamstring's donor site in anterior cruciate ligament reconstruction. This approach may enhance early rehabilitation and patient satisfaction.

Two-stage ligament reconstruction with remnant preservation as treatment of knee dislocation

OBJECTIVE

The purpose of this study was to evaluate the clinical outcomes of two-stage reconstruction (peripheral reconstruction in phase I and central anterior cruciate ligament (ACL) / posterior cruciate ligament (PCL) reconstruction in phase II) with remnant preservation for patients with knee dislocation.

METHODS

A total of 70 patients (10 IIIM, 17 IIIL, and 43 IV) with knee dislocation were randomly divided into the remnant-preserved group and the simple reconstruction group. Patients underwent two-stage reconstruction, including the reconstruction of collateral ligament in phase I and the reconstruction of ACL/PCL in phase II (12 weeks after phase I). Grafts were harvested from the semitendinosus and gracilis tendons from both lower limbs. After the surgery, the joint flexion and extension, bone tunnel and ligament healing, and joint stability were evaluated.

RESULTS

After the surgery, the lateral stability recovered in all patients, and X-ray revealed a good position of bone tunnel. Follow-up was performed at 12 months postoperatively and ranged from 24 to 91 months. At the final follow-up, knee flexion angle, IKDC, Lysholm, and Tegner scores were all higher in both groups compared to the preoperative period. Notably, the remnant-preserved group showed superior results in these parameters compared to the simple reconstruction group. There was statistical significance between the two groups in terms of the Lachman test.

CONCLUSION

The knee function was well recovered after two-stage ligament reconstruction with remnant preservation.

Is remnant preservation in anterior cruciate ligament reconstruction superior to the standard technique? An overview of systematic reviews

BACKGROUND

Anterior cruciate ligament injury is a common knee joint injury. Anterior cruciate ligament reconstruction is a common surgical treatment to treat anterior cruciate ligament injury. It may have certain advantages to retain the ligament stump during the operation, but the results of systematic evaluation on whether to retain the ligament stump are different. The conclusion is still controversial, and the quality needs to be strictly evaluated.

OBJECTIVE

To evaluate the methodological quality, risk of bias, reporting quality and evidence quality of the systematic review of remnant preservation in anterior cruciate ligament reconstruction, and to provide reference for clinical work.

METHODS

We systematically searched the system evaluations in 8 electronic databases, the languages were limited to Chinese and English, and the time limit was from the establishment of the database to June 2023. Two reviewers independently screened literature and extracted data. The methodological quality, risk of bias, reporting quality and quality of evidence were evaluated by AMSTAR-2, ROBIS, PRISMA and GRADE tools.

RESULTS

A total of 14 systematic reviews were included. The evaluation of results showed that the methodological quality of the included systematic reviews was relatively low, of which 5 were low quality and 9 were critically low quality. A small number of systematic reviews were low risk of bias. The system evaluation reports are relatively complete, but the lack of program registration is a common problem. A total of 111 pieces of clinical evidence were extracted from the included 14 systematic reviews. The quality of evidence was generally low, with only 7 pieces of high-quality evidence, 45 pieces of medium-quality evidence, and the rest were low and very low-quality evidence. Among the reasons for relegation, imprecision is the most common, followed by inconsistency and indirectness. The existing evidence shows that patients after anterior cruciate ligament reconstruction with remnant preservation have certain advantages in knee joint function, joint stability and proprioception recovery, which may be a more effective surgical method. However, it may also increase the incidence of postoperative complications and adverse reactions.

CONCLUSION

Compared with Standard Technique, Remnant Preservation in Anterior Cruciate Ligament Reconstruction has more advantages in restoring joint function and stability and proprioception. But the potential risks should also be considered by surgeons. At present, the quality of evidence is generally low, and the reliability of the conclusion is insufficient. It still needs to be verified and further in-depth research is needed.

Comparative Study of Graft Healing in 2 Years after “Tension Suspension” Remnant-Preserving and Non-Remnant-Preserving Anatomical Reconstruction for Sherman Type II Anterior Cruciate Ligament Injury

Purpose: To evaluate the degree of graft healing after “tension suspension” reconstruction of “Sherman II” anterior cruciate ligament injuries versus non-remnant preserving anatomical reconstruction and to compare the clinical outcomes of the two procedures. Method: The clinical data of 64 patients were retrospectively included. There were 31 cases in the “tension suspension” remnant-preserving reconstruction group and 33 cases in the non-remnant-preserving anatomical reconstruction group. The International Knee Documentation Committee (IKDC) score, the Tegner score, and the Lysholm activity score were assessed preoperatively and at 6 months, 1 year, and 2 years postoperatively, respectively. The signal/noise quotient (SNQ) of the grafts was measured at 6 months, 1 year, and 2 years after surgery to quantitatively evaluate the maturity of the grafts after ACL reconstruction; the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the reconstructed ACL region of interest (ROI) were measured using DTI. Result: A total of 64 patients were included in the study. The mean SNQ values of the grafts in the 6 months, 1 year, and 2 years postoperative remnant-preserving reconstruction (RP) groups were lower than those in the non-remnant-preserving (NRP) reconstruction group, with a statistically significant difference (p < 0.05). At each postoperative follow-up, the SNQ values of the tibial and femoral sides of the RP group were lower than those of the NRP group; the SNQ values of the femoral side of the grafts in both groups were higher than those of the tibial side, and the differences were statistically significant (p < 0.05). At 6 months, 1 year, and 2 years postoperatively, the FA and ADC values of the grafts were lower in the RP group than in the NRP group, and the differences were statistically significant (p < 0.05); the IKDC score and Lysholm score of the RP group were higher than the NRP group, which was statistically significant (p < 0.05). Conclusion: For Sherman II ACL injury, the graft healing including ligamentization and revascularization at 2 years after the “tension suspension” remnant-preserving reconstruction was better than that of non-remnant-preserving anatomic reconstruction.

Consensus statement on data to be entered in the ACL tear registry: SFA-DataLake

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction is a frequent procedure, with room for improvement by rehabilitation measures and associated peripheral and meniscal surgeries that are currently under assessment, requiring follow-up. Outside France, there have been ACL registries for 20 years now. The French Arthroscopy Society (SFA) decided to set up an ACL tear registry within its SFA DataLake registry platform.

MATERIAL AND METHOD

This article presents the methodology underlying the ACL Tear Registry: i.e., identification, definition and coding of essential and relevant data. A test phase comprised an initial assessment to improve data quality and overall coherence, to optimize data-entry time for patients and practitioners, who are the guarantors of the registry's use and efficacy.

RESULTS

The SFA DataLake ACL Tear Registry was made available to SFA members in December 2021. It aims to enable a review of practices for surgeons, early detection of failure of procedures and implants, with rates of failure and abnormal complications, and identification of prognostic factors for outcome, especially regarding original items that do not figure in previous registries.

CONCLUSION

SFA DataLake strikes a balance between "indispensable" and "original" items. The choice of contents and data quality is founded on a robust methodology with overall coherence, enabling analysis of large cohorts and comparisons with the literature and other registries. However, it remains to assess rates of data entry and item relevance as the Registry progresses.

LEVEL OF EVIDENCE

IV.

Remnant preserving ACL reconstruction with a functional remnant is related to improved laxity but not to improved clinical outcomes in comparison to a nonfunctional remnant

PURPOSE

The Anterior cruciate ligament (ACL) remnant has been pointed out as a ligamentization enhancer. Nonetheless, the remaining tissue can be functional if it still provides some stability or nonfunctional. This study intends to compare the clinical results and knee stability of functional vs. nonfunctional remnant preservation ACL reconstruction (ACLR).

METHODS

One hundred and seventy-five patients with ACL injuries were included and underwent remnant preservation ACLR. They were divided into two groups accordingly to remnant tissue functionality: functional (Group F) and nonfunctional (Group NF). Primary outcome was defined as patient reported outcomes measured with Lysholm, IKDC and Tegner continuous scales and improvements. Secondary outcomes comprised of Lachman test, anterior drawer test, pivot shift test, extension and flexion deficit, graft coverage by remnant preserved tissue and failure rate (persistent instability or new ACL lesion). Menisci lesions, cartilage lesions and time to surgery were also recorded for each group.

RESULTS

One hundred and forty-four patients were available at a mean of 30.2 ± 10.1 months: 69 Functional and 75 Nonfunctional. Lysholm, IKDC and Tegner functional outcomes demonstrated no difference between the groups, Functional compared to Nonfunctional: 88.4 ± 10.5 vs. 92.2 ± 4.9, n.s. and 83.2 ± 11.3 vs. 87 ± 5.3, n.s. and 6 (5-10) vs. 6 (5-9), n.s., respectively. Lysholm and IKDC functional outcomes improvements demonstrated differences between the groups: Functional compared to Nonfunctional (39.3 ± 9.4 vs. 42.3 ± 7.4, p = 0.014 and 37.7 ± 10 vs. 41.0 ± 6.6, p = 0.032); however, they were not clinically significant. Functional group showed more stability on physical examination pre- and post-operatively (p < 0.001, p < 0.001). There was no difference regarding extension deficit (n.s.); however, functional group had more flexion deficit (p = 0.02). Nonfunctional group had better graft coverage (p = 0.001). There was no difference regarding failure rate: 4% vs. 9%, (n.s.).

CONCLUSION

Both remnant preservation ACLR techniques were able to achieve satisfactory functional outcomes. A functional remnant was not related to improved functional outcomes in comparison to a nonfunctional remnant; however, it was related to less laxity pre and postoperatively and inferior graft coverage.

LEVEL OF EVIDENCE

II.

The importance of continuous remnant preservation in anterior cruciate ligament reconstruction

PURPOSE

Selective anteromedial or posterolateral bundle reconstruction is recognized as a treatment modality in partial anterior cruciate ligament (ACL) reconstruction (ACLR) with a biomechanically sufficient ACL remnant. However, there is paucity in literature investigating clinical outcomes of standard ACLR with preservation of residual continuous but biomechanically insufficient ACL tissue. The aim of this study was to investigate the influence of preservation of residual continuous but biomechanical insufficient ACL tissue in standard ACLR on complication and repeat surgery rate, and patient reported and clinical outcome.

METHODS

The retrospective cohort comprised 134 patients (age 23 ± 7 years; Tegner 6 ± 3) with an isolated acute ACL tear. In 67 patients, residual continuous but biomechanically insufficient ACL tissue was present and preserved based on visual inspection, probing of the ACL tissue and Lachman test under arthroscopic view (standard reconstruction with tissue preservation; SRTP). These patients were matched to 67 patients that underwent ACLR where no residual ACL tissue could be preserved (standard reconstruction; SR) based on gender, age and chondral and/or meniscal status. Clinical failure (recurrent instability, pathological ACL graft laxity and/or ACL graft discontinuity), other complication and repeat-surgery rate within index surgery and 1-year and within index surgery and 2-year follow-up, and patient reported and clinical outcomes at 1-year and at 2-year follow-up were compared.

RESULTS

A statistically significant lower clinical failure rate within index surgery and 1-year (SRTP, 3%; SR, 13%; P = 0.028) and within index surgery and 2-year follow-up (SRTP, 3%; SR, 23%; P = 0.001), and revision ACL surgery rate within index surgery and 1-year (SRTP, 2%; ST, 10%; P = 0.029) and within index surgery and 2-year follow-up (SRTP, 2%; SR, 18%; P = 0.001) was found in the SRTP group. No statistically significant differences were found for other investigated outcomes in patients that were without clinical failure.

CONCLUSION

This study shows that in ACLR surgery, preservation of residual continuous but biomechanical insufficient ACL tissue might lead to lower clinical failure rate and ACL revision surgery rate within index surgery and 1-year, and within index surgery and 2-year follow-up compared to standard ACLR where no residual continuous ACL tissue could be preserved.

LEVEL OF EVIDENCE

III.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Remnant preservation with tensioning can improve the clinical outcome after anterior cruciate ligament reconstruction

BACKGROUND

Many studies exist about remnant preservation in anterior cruciate ligament (ACL) reconstruction. However, concern remains for development of a cyclops lesion during remnant preservation. To prevent this, a tensioning method has been suggested. Current study evaluated the clinical and radiologic results of remnant preservation in ACL reconstruction with tensioning compared to classical ACL reconstruction.

METHODS

From January 2016 to June 2017, ACL reconstruction patients who underwent magnetic resonance imaging (MRI) 2 years postoperatively were enrolled. For comparison, all participants were divided in two groups: remnant preservation with tensioning (group R) and controls (group C). Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), Lysholm scores, and incidence of symptomatic cyclops lesions were evaluated. Radiologically, signal-to-noise quotient (SNQ) and size of the synovium on MRI as well as anterior instability in Telos stress radiographs were evaluated.

RESULTS

A total of 64 patients were enrolled (42 in group R and 22 in group C). The IKDC score in group R (70) was better than that in group C (62; p < 0.05). One patient in group R had a cyclops lesion with clinical symptoms and arthroscopic excision was recommended. Radiologically, the SNQ, synovium area, and anterior instability on Telos radiography showed no difference between the two groups.

CONCLUSION

Remnant preservation with tensioning is a good option for ACL reconstruction without the development of a cyclops lesion.

Remnants-preserving ACL reconstruction using direct tendinous graft fixation: a new rat model

BACKGROUND

Anterior cruciate ligament (ACL) repair techniques are new emerging strategies prevailing, in selected cases, over standard reconstruction of the ACL with excision of its remnants. Mid-substance ACL tears represent a challenge for ACL repair techniques, and remnants-preserving ACL reconstruction (rp-ACLR) using an autograft remains the recommended treatment in this situation. However, morbidity associated with the autograft harvesting prompts the need for alternative surgical strategies based on the use of synthetic scaffolds. Relevant small animal models of mid-substance tears with ACL remnants preservation and reconstruction are necessary to establish the preliminary proof of concept of these new strategies.

METHODS

A rat model of rp-ACLR using a tendinous autograft after complete mid-substance ACL transection was established. Twelve weeks following surgery, clinical outcomes and knee joints were assessed through visual gait analysis, Lachman tests, thigh perimeter measurements, magnetic resonance imaging, micro-computed tomography, and histology, to evaluate the morbidity of the procedure, accuracy of bone tunnel positioning, ACL remnants fate, osteoarthritis, and autograft bony integration. Results were compared with those obtained with isolated ACL transection without reconstruction and to right non-operated knees.

RESULTS AND DISCUSSION

Most operated animals were weight-bearing the day following surgery, and no adverse inflammatory reaction has been observed for the whole duration of the study. Autograft fixation with cortical screws provided effective graft anchorage until sacrifice. Healing of the transected ACL was not observed in the animals in which no graft reconstruction was performed. rp-ACLR was associated with a reduced degeneration of the ACL remnants (p = 0.004) and cartilages (p = 0.0437). Joint effusion and synovitis were significantly lower in the reconstructed group compared to the transected ACL group (p = 0.004). Most of the bone tunnel apertures were anatomically positioned in the coronal and/or sagittal plane. The most deviated bone tunnel apertures were the tibial ones, located in median less than 1 mm posteriorly to anatomical ACL footprint center.

CONCLUSION

This study presents a cost-effective, new relevant and objective rat model associated with low morbidity for the preliminary study of bio-implantable materials designed for remnants-preserving ACL surgery after mid-substance ACL tear.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Graft healing after anterior cruciate ligament reconstruction (ACLR)

Anterior cruciate ligament reconstruction (ACLR) is a commonly performed procedure in Orthopaedic sports medicine. With advances in surgical techniques providing better positioning and fixation of the graft, subsequent graft failure to certain extent should be accounted by poor graft healing. Although different biological modulations for enhancement of graft healing have been tried in different clinical and animal studies, complete graft incorporation into bone tunnels and the “ligamentization” of the intra-articular part have not been fully achieved yet. Based on the understanding of graft healing process and its failure mechanism, the purpose of this review is to combine both the known basic science & clinical evidence, to provide a much clearer picture of the obstacle encountered in graft healing, so as to facilitate researchers on subsequent work on the enhancement of ACL graft healing.

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.

Remnant preservation does not affect accuracy of tibial tunnel positioning in single-bundle ACL reconstruction

PURPOSE

Remnant preservation, in anterior cruciate ligament (ACL) reconstruction, has potential biological advantages. However, graft positioning remains vital to functional outcome and the prevention of failure. The aim of this study was to investigate the accuracy and precision of tibial tunnel positioning in remnant preservation single-bundle hamstring reconstruction.

METHODS

Fifty consecutive adult patients, with isolated ACL rupture, were recruited to a prospective study. Remnant preservation was performed in all cases where > 25% of the native ACL was present. Three-dimensional computer tomography was preformed 3-6 months post-operatively to assess tibial tunnel position (using a grid-based measurement). Accuracy and precision of this technique were assessed against published anatomical data in direct comparison with the group where remnant preservation could not be performed.

RESULTS

Two patients withdrew following surgery. In the remaining groups (31 remnant preservation; 17 non-remnant preservation), no difference was demonstrated in tunnel position (40.4 ± 6.7% (anterior-to-posterior) and 47.4 ± 1.5% (medial-to-lateral) vs. 38.8 ± 4.9% and 46.7 ± 1.5%, respectively; n.s.), accuracy (6.1% vs. 4.8%; n.s.) or precision (3.9% vs. 2.8%; n.s.).

CONCLUSIONS

Remnant preservation can be safely performed without compromising tunnel position. Therefore, the potential benefits of this technique can be utilised, in clinical practice, without sacrificing the ability to optimize tibial tunnel positioning.

LEVEL OF EVIDENCE

III.

Sandwich-Style Anterior Cruciate Ligament Reconstruction: Double-Bundle Anterior Cruciate Ligament Reconstruction With In-Between Remnant Preservation

Various degree of remnant tissues exists following anterior cruciate ligament (ACL) injury. Making use of these tissues may be helpful for the reconstructed ACL from many aspects. There are many methods of remnant preservation and use, as well as many types of combined ACL reconstruction. However, the most effective methods of remnant reuse as well as ACL reconstruction are still being pursued. We introduce an anatomical double-bundle transtibial ACL reconstruction with in-between remnant preservation technique named sandwich-style ACL reconstruction. The indication of this technique is complete ACL tear with a large volume of connectable remnant. The main tricks of this technique are proper ligation of the remnant, proper location of the anteromedial-bundle tibial tunnels, and passing the anteromedial bundle through the shallow side of the remnant. We believe the introduction of this technique will provide more options for remnant preservation and ACL reconstruction.

Remnant-Preserving Anterior Cruciate Ligament Reconstruction: Remnant Envelope Technique

The awareness of anterior cruciate ligament (ACL) injuries and their treatment is increasing among athletes and within the general population, so patients report early to orthopaedic surgeons. Because we encounter a thick ACL stump during arthroscopic ACL reconstruction, an attempt is made to preserve this stump. Remnant preservation-although promising in terms of graft healing because it enhances cell proliferation, revascularization, and regeneration of the proprioceptive organs in the reconstructed ACL-does not come without complications, such as cyclops lesions, impingement, and extension loss. These problems can be detrimental to an athlete's return to his or her preinjury level after ACL reconstruction. Therefore, we describe a technique in which the ACL is reconstructed using hamstring autograft and suture passes are made through the remnant with an antegrade suture-passing device. After anatomic tunnel drilling, the remnant is tensioned, along with the reconstructed ACL, at the femoral end without the use of an extra implant. Femoral-side fixation is achieved with an adjustable-loop button (Procinch; Stryker) and a bio-composite interference screw (Biosure Regenesorb; Smith & Nephew) on the tibial end. As the sutured remnant is tensioned and knots are made over the button, the remnant envelopes the graft in the orientation of the native ACL, which can be helpful for early and better ligamentization of the graft. The potential advantages of this technique are as follows: orientation of the remnant along the collagen of the ACL graft; no loose ACL stump in the notch, thus preventing cyclops lesions; retention of the proprioceptive organs in the ligament; and no extra implant.

Synovialization and Revascularization Enhancement in Repaired and Reconstructed ACL: PCL Fat Pad Transfer Technique

The rapid development of anterior cruciate ligament (ACL) reconstruction and repair techniques has significantly improved the outcomes of these procedures. However, there is still some place for how to improve surgical techniques to limit the amount of revision surgeries. Over the past decade, biological solutions and methods of ligament remodeling enhancement have been proposed. The use of the native ACL remnants has been the most thoroughly analyzed technique. However, despite its benefits, this technique may not to be sufficient to improve outcomes and may cause some technical difficulties. On the other hand, the posterior cruciate ligament (PCL) fat pad contains an abundant synovial vascular network and is located in close proximity to the ACL, which makes it a potential biological donor place of cells and tissue that could enhance the ligamentization of the repaired or reconstructed ACL. To optimize the use of this donor site, we propose the technique of ACL synovialization and revascularization enhancement with a PCL fat pad transfer.

Clinical Outcome of Remnant-Preserving and I.D.E.A.L. Femoral Tunnel Technique for Anterior Cruciate Ligament Reconstruction

Objective

To assess the clinical results of the remnant‐preserving and I.D.E.A.L. femoral tunnel technique in the arthroscopic treatment of anterior cruciate ligament (ACL) injuries.

Methods

This was a retrospective single‐center, single‐surgeon study reviewing data from November 2016 to March 2019. Based on our inclusion/exclusion criteria, a total of 31 patients (18 males, 13 females; mean age, 23.6 years) who underwent arthroscopic ACL reconstruction with the remnant preservation and I.D.E.A.L. femoral tunnel technique were recruited and had a minimum follow‐up of 12 months. Clinical data and status of knee stability were recorded. The International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale were collected both preoperatively and at a minimum of 1‐year follow‐up.

Results

Statistically significant differences were detected between the preoperative and postoperative values for Lachman test and pivot‐shift test (P < 0.01). The mean postoperative Lysholm score was 89.6 ± 9.4, whereas the mean preoperative Lysholm score was 47.3 ± 12.8 (P < 0.01). The mean Tegner activity score was significantly higher at postoperative evaluation than at preoperative evaluation (6.5 ± 2.1 vs 2.6 ± 1.8; P < 0.01). The mean IKDC score was significantly improved from 49.5 ± 10.6 preoperatively to 88.2 ± 10.7 postoperatively (P < 0.01). No case of infection was reported. No radiograph showed any joint space narrowing or degenerative change at the last postsurgical follow‐up.

Conclusion

The anatomical remnant‐preserving and I.D.E.A.L. femoral tunnel technique achieves a satisfactory clinical outcome and provides an effective option for the treatment of ACL injuries.