A comparison of acute and chronic anterior cruciate ligament reconstruction using LARS artificial ligaments: a randomized prospective study with a 5-year follow-up

Efficacy and safety of early versus delayed reconstruction for anterior cruciate ligament injuries: A systematic review and meta-analysis

OBJECTIVE

To critically evaluate the efficacy and safety of early versus delayed anterior cruciate ligament reconstruction (ACLR) for anterior cruciate ligament (ACL) injuries based on the different cut-off values of the timing of operation.

METHODS

PubMed, Medline, Embase, Cochrane library, China National Knowledge Infrastructure, Chinese Biomedical Literature, and Wanfang Digital Periodical database were searched from inception to November 2022 without language restrictions. Randomized controlled trials (RCTs) and cohort studies (CSs) comparing early ACLR with delayed ACLR for ACL injuries were included.

RESULTS

Twenty-four studies (10 RCTs and 14 CSs) were included. According to the information from included studies, 3 weeks, 4 weeks, 6 weeks, 6 months, and 12 months after ACL injuries were considered as the cut-off values of early and delayed ACLR. When 4 weeks were considered as the cut-off value, early ACLR could significantly improve Lysholm score, IKDC score and VAS score at 6 and 12 months postoperatively and decrease the incidence of adverse events compared with delayed ACLR (P < 0.05). However, no statistically significant difference in positive rate of Lachman test and incidence of meniscus injuries and chondral lesions between the two groups when 3 weeks, 6 weeks, 6 months or 12 months after ACL injuries were considered as the cut-off values of early and delayed ACLR (P > 0.05).

CONCLUSION

The present study suggests that early ACLR, especially conducted within 3-4 weeks after ACL injuries, may be more effective for improving knee function and relieving pain compared with delayed ACLR. More high-quality RCTs are warranted.

Synthetic grafts for anterior cruciate ligament reconstructive surgery

The quest for a good and durable substitute to anterior cruciate ligament (ACL) is driving scientists to explore new promising areas of research. Autologous and allogenic ligament reconstruction bring satisfactory results in managing ACL surgery although their use is associated with significant drawbacks. To overcome the limitations of biologic grafts, many artificial devices have been developed and implanted as a substitute to the native ACL over the past decades. Although many synthetic grafts used in the past have been withdrawn from the market due to early mechanical failures ultimately leading to synovitis and osteoarthritis, there is recently a resurgence of interest in the use of synthetic ligaments for ACL reconstruction. However, this new generation of artificial ligaments, despite promising initial results, have shown to produce serious side effects such as high rupture rates, insufficient tendon-bone healing and loosening. For these reasons, recent advancements in biomedical engineering are focusing on improving technical features of artificial ligaments combining mechanical properties to biocompatibility. Bioactive coatings and surface modification methods have been proposed to enhance synthetic ligament biocompatibility and promote osseointegration. The path to the development of a safe and effective artificial ligament is still full of challenges, however recent advancements are leading the way towards a tissue-engineered substitute to the native ACL.

Allogeneic Tendon Transplantation for the Treatment of Pathological Patellar Ligament Defect in Children: Technical Note and 4-Year Follow-Up

OBJECTIVE

The absence of patellar ligament will bring about a severe negative impact on daily life. Many reconstruction techniques have been described in adults. However, there is a lack of technical introduction regarding the reconstruction of the patellar ligament in children. The purpose of this study was to report a surgical technique for reconstructing the patellar ligament in children.

METHOD

A retrospective analysis of the clinical data on a patellar ligament (tendon sheath fibroma) patient with allogeneic tendon reconstruction. An 8-year-old child with postoperative recurrence of left patellar ligament tumor was enrolled in our study. Anterior tibialis tendon allograft was used to reconstruct the patellar ligament after complete resection of the patellar ligament for the tumor. The tunnels were constructed on the deep surface of the tibial tubercle and the root of the quadriceps tendon (to decrease the harmful impact on patella development), respectively. The allogeneic tendon was passed through the tunnels above in the shape of "8," and the two ends of the tendon were attached to the bleeding bone bed at the inferior edge of the patella with suture anchors to achieve better bone-tendon healing. During the follow-up, the knee's range of motion and imaging manifestations were recorded.

RESULT

Postoperative pathology suggests chondromesenchymal hamartoma, a rare benign soft tissue tumor different from the previous operation (tendon sheath fibroma). During the 4-year follow-up, the patient's active range of motion of the knee achieved 0° to 120°; and the patient could walk normally without any external help. Physical examinations (the apprehension sign and J sign) showed no ligamentous instability or patellar ligament tenderness. Imaging analysis showed that the ratio length of the patellar ligament to the patella was almost normal. The integrity, continuity, and shape of the allogeneic ligament showed excellent results in MRI. Combined with clinical and imaging findings, allogeneic tendon patellar ligament reconstruction was deemed successful.

CONCLUSION

Allogeneic ligament reconstruction technique can provide a treatment option by reconstructing the extensor mechanism, minimizing the impact on patellar development, and augmenting biological healing for children with the absence of the patellar ligament.

Optimal Timing of Anterior Cruciate Ligament Reconstruction in Patients With Anterior Cruciate Ligament Tear: A Systematic Review and Meta-analysis

IMPORTANCE

The timing of surgery has been regarded as a key factor in anterior cruciate ligament reconstruction (ACLR), and early vs delayed ACLR remains a controversial topic.

OBJECTIVE

To synthesize up-to-date published data from randomized clinical trials (RCTs) comparing early vs elective delayed ACLR for patients with ACL deficiency, in terms of clinical outcomes and complications.

DATA SOURCES

The PubMed, Cochrane Library, and Web of Science databases were systematically searched until September 9, 2022.

STUDY SELECTION

All published RCTs comparing clinical and functional outcomes and complications associated with early ACLR vs elective delayed ACLR.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted relevant data and assessed the methodological quality following the PRISMA guidelines.

MAIN OUTCOMES AND MEASURES

Due to the clinical heterogeneity, the random-effects model was preferred. The primary outcomes were functional outcomes and complications. The Mantel-Haenszel test was used to evaluate dichotomous variables and the inverse variance method was used to assess continuous variables.

RESULTS

This meta-analysis included 972 participants in 11 RCTs stratified by follow-up duration. The following factors did not differ between early and delayed ACLR: operative time (mean difference, 4.97; 95% CI, -0.68 to 10.61; P = .08), retear (OR, 1.52; 95% CI, 0.52-4.43; P = .44), and infection (OR, 3.80; 95% CI, 0.77-18.79; P = .10). There were also no differences between groups in range of motion, knee laxity, International Knee Documentation Committee (IKDC rating scale), and Tegner score. IKDC score (mean difference, 2.77; 95% CI, 1.89-3.66; P < .001), and Lysholm score at 2-year follow-up (mean difference, 2.61; 95% CI, 0.74-4.48; P = .006) significantly differed between early and delayed ACLR. In addition, the timing of surgery was redefined in the included RCTs and subgroup analyses were performed, which validated the robustness of the principal results.

CONCLUSION AND RELEVANCE

This systematic review and meta-analysis found that early ACLR was not superior to delayed ACLR in terms of most factors analyzed, except for IKDC and Lysholm scores. This information should be available to patients with ACL deficiency and clinicians as part of the shared decision-making process of treatment selection.

The Chinese knotting technique assist anatomical anterior cruciate ligament reconstruction for aggressive rehabilitation

Aggressive rehabilitation after anterior cruciate ligament (ACL) reconstruction may result in better clinical outcomes and fewer complications such as knee stiffness and weakness. We explored the effect of the Chinese knotting technique (CKT) for aggressive rehabilitation after ACL reconstruction. Ninety-one anatomical ACL reconstruction cases from 2016 to 2020 were retrospectively reviewed. All patients were operated by the same senior physician and his team. According to the reconstruction with or without CKT, the patients were divided into 2 groups. Both groups received aggressive rehabilitation. The follow-up time of 91 patients was more than 2 years. In total, 43 out of the 91 patients were in the CKT group, and 48 were in the routine group. The knee joint kinematics recorded by Opti_Knee revealed no significant difference among the CKT group, the routine group, and healthy adults at 3, 6, 12, and 24 months after the operation, respectively. The internal and external rotation angle and the anteroposterior displacement at 3 and 6 months after the operation in the CKT group were smaller than in the routine group and were similar to that of the healthy adults. There was no significant difference in flexion and extension angle, varus or valgus angle, proximal-distal displacement, or the internal or external displacement between the 2 groups. In addition, there was no significant difference in 6 degrees of freedom of the knee between the 2 groups at 12 and 24 months after the operation, respectively, which was similar to healthy adults. Compared to the routine group, the International Knee Documentation Committee scores were significantly higher in the CKT group at the 3, 6, and 12 months, respectively, but no difference was observed at 24 months (P = .749). The Lysholm score was significantly higher in the CKT group at the 3 and 6 months postoperatively, while there was no difference at 12 and 24 months, respectively. In short-term observation, the ACL reconstruction with CKT, which can sustain aggressive rehabilitation and prevent the loosening of ACL graft, can lead to better clinical outcomes and kinematics recovery of the knee compared to routine technique.

Differences in artificial ligament graft osseointegration of the anterior cruciate ligament in a sheep model: a comparison between interference screw and cortical suspensory fixation

Background

Interference screws are the most common femoral fixation for anterior cruciate ligament (ACL) reconstruction with polyethylene terephthalate (PET) artificial ligaments. However, interference screws have several disadvantages, such as the risk of one tunnel blowout and damage to the graft. Suspensory fixations have the advantages of high tensile strength and promotion of graft bone contact. The purpose of this study was to compare PET artificial ligament graft osseointegration between interference screw fixation (ISF) and cortical suspensory fixation (CSF) for ACL reconstruction.

Methods

Forty sheep underwent ACL reconstruction of the right knee with PET artificial ligament. The graft was fixed with ISF or CSF for femoral fixation. Animals were randomly assigned to the ISF (n=20) or the CSF (n=20) groups. The sheep were sacrificed at 3 or 12 months postoperatively for biomechanical tests, micro computed tomography (micro-CT) scans, and histological assessments.

Results

The mean load-to-failure between the CSF group (836±355 N) appeared higher than that of the ISF group (604±277 N) at 3 months, but no significant difference was detected between the groups (P=0.24). At 12 months, there was also no significant difference in load-to-failure between the CSF and ISF groups (1,194±350 vs. 1,097±764 N; P=0.78). According to the micro-CT scan results, the femoral bone tunnel diameter of the ISF group appeared larger than that of the CSF group at 3 months (12±1 vs. 10±1 mm; P=0.02) and similar to that of the CSF group at 12 months (12±1 vs. 11±2 mm; P=0.38). Furthermore, histological results showed that at the graft-tunnel interface of the femoral tunnel aperture, disoriented fibers formed in the ISF group while oriented and dense fibers formed in the CSF group.

Conclusions

ACLR with synthetic ligament by cortical suspension devices with adjustable loops demonstrated a better graft-bone healing capacity at the femoral tunnel aperture compared with that from titanium interference screws over 12 months postoperatively. No significant difference was found in biomechanical strength between the two fixation methods during the early healing stage.

A Systematic Review of Randomized Controlled Trials in Anterior Cruciate Ligament Reconstruction: Standard Techniques Are Comparable (299 Trials With 25,816 Patients)

Purpose

To provide an overview of all published randomized controlled trials (RCTs) in anterior cruciate ligament reconstruction (ACLR) summarizing the available evidence.

Methods

Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the Cochrane FIGCentral Register of Controlled Trials, Ovid MEDLINE, and Embase for RCTs of ACLR from their inception to August 26, 2020. Outcome measure was whether RCTs reported statistically significant findings. RCTs were then classified according to their intervention groups in a narrative synthesis of the evidence.

Results

In total, 299 RCTs met the inclusion criteria and were included with a total number of 25,186 patients. Only 30 RCTs (10%) reported significant differences between the intervention and the control groups. These included 101 RCTs on grafts, 20 RCTs on tunnel placements, 48 RCTs on graft fixation, 42 RCTs on single-bundle compared with double-bundle reconstructions, 11 RCTs on additional procedures, 11 RCTs on graft tensioning, 5 RCTs on timing of surgery, 25 RCTs on technical variations from standard techniques, 6 RCTs on ACL repair, 5 RCTs on navigation, 16 RCTs on perioperative management, and 9 RCTs on other aspects of ACLR. Only 14 RCTs (4.7%) reported outcomes beyond 10 years with greater allograft failures compared with autografts, high incidence of osteoarthritic changes in reconstructed knees (22%-100%), with no significant differences in outcomes between bioabsorbable or metal screws for graft fixation, patellar versus hamstrings or single- versus double-bundle reconstructions.

Conclusions

The evidence indicates that a standard arthroscopic single- or double-bundle ACLR with hamstrings/patella autografts, transportal technique, and fixation techniques familiar to the surgeon leads to comparable results. This evidence offers surgeons the flexibility to use standard and cost-effective techniques and achieve comparable outcomes.

Level of Evidence

Level II; systematic review of Level I-II randomized controlled trials.

Surgical Timing Does Not Interfere on Clinical Outcomes in Combined Reconstruction of the Anterior Cruciate Ligament and Anterolateral Ligament: A Comparative Study With Minimum 2-Year Follow-Up

PURPOSE

To compare the functional outcomes, knee stability, failure rate and complication rates of combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction with hamstrings grafts between acute and chronic cases.

METHODS

Consecutive patients who underwent combined ACL and ALL reconstruction with hamstrings grafts were evaluated. Patients operated on less than 8 weeks after injury were allocated to group 1, and the others were allocated to group 2. Demographic data, knee stability, and functional outcomes of the 2 groups were evaluated.

RESULTS

Thirty-four patients in the acute group and 96 in the chronic group were evaluated. The follow-up time was similar between the groups (28.7 ± 5.2 [24-43] months vs 29.4 ± 7.2 [24-58] months; P = 0.696). No differences were found between the groups in age, sex, trauma mechanism, presence of knee hyperextension, graft diameter, and meniscal injuries. There was no difference between the groups in the postoperative KT-1000 and in the pre- or postoperative pivot shift. The preoperative KT-1000 was higher in group 2 (7.9 ± 1.1 vs 7.4 ± 1.2; P = 0.031). There were no differences in the International Knee Documentation Committee or Lysholm. Three (2.3%) patients developed failure, 1 (2.9%) in group 1 and 2 (2.1%) in group 2. The total complication rate was 10% and did not differ between the groups.

CONCLUSIONS

Combined ACL and ALL reconstruction has similar outcomes in patients undergoing surgery in the acute and chronic phases. Patients with chronic injury have similar knee stability, functional scores, and failure rates as acute-injury patients, and patients with acute injury have no more complications than chronic patients.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic trial.

A systematic review comparing the results of early vs delayed ligament surgeries in single anterior cruciate ligament and multiligament knee injuries

PURPOSE

The purpose of this study was to compare clinical outcomes and incidence of concomitant injuries in patients undergoing early vs delayed surgical treatment of single anterior cruciate ligament (ACL) injury and multiligament knee injury (MLKI).

METHODS

A literature search using PubMed, Embase, the Cochrane Library, the Cumulative Index to Nursing and Allied Health, and Scopus from their inception to April 30, 2020 was conducted. Studies with levels I to IV evidence reporting the incidence of meniscus or cartilage injury according to early vs delayed surgery in single ACL injuries and MLKIs were included. In the meta-analysis, data based on the number of meniscus and cartilage injuries were extracted and pooled. Lysholm and Tegner scores were analyzed using two-sample Z-tests to calculate the non-weighted mean difference (NMD). A meta-regression analysis was also performed to determine the effect of single ACL injury and MLKI/study design.

RESULTS

Sixteen studies on single ACL injury and 14 studies on MLKI were included in this analysis. In the analysis, there were significant decreases in Lysholm score (NMD - 5.3 [95% confidence interval (CI) - 7.37 to - 3.23]) and Tegner score (NMD - 0.25 [95% CI - 0.45 to - 0.05]) and increases in risk of meniscus tear (odds ratio [OR] 1.73 [95% CI 1.1-2.73], p = 0.01) and cartilage injury (OR 2.48 [95% CI 1.46-4.2], p = 0.0007) in the delayed surgery group regardless of single ACL injury or MLKI. The result of the meta-regression analysis indicated that single ACL injury and MLKI/study design were not significant moderators of overall heterogeneity (p > 0.05).

CONCLUSIONS

Our study suggests that delayed ACL surgery significantly resulted in a higher risk of meniscus tear and cartilage injury and decreased Lysholm and Tegner scores compared to early ACL surgery. The Lysholm scores in the delayed MLKI surgery group were significantly decreased, but the risks of meniscus tear and cartilage injury in the delayed MLKI surgery group remained unclear.

LEVEL OF EVIDENCE

Level III, meta-analysis.

Predictive factors for failure of anterior cruciate ligament reconstruction via the trans-tibial technique

INTRODUCTION

Factors for graft failure after trans-tibial (TT) ACL reconstruction, including anterolateral ligament (ALL) injury and degree of synovialization, remain unclear. This study is to evaluate the risk factors for graft failures after TT ACL reconstruction including ALL injury and synovialization.

MATERIALS AND METHODS

A total 391 patients who underwent primary TT ACL reconstruction were included. Failure was defined as greater than grade 2 laxity on the Lachman or pivot shift tests or 5 mm of anterior translation on stress radiograph. After applying inclusion/exclusion criteria, 31 patients with failure were categorized as group 1 and 89 patients without failure were categorized as group 2. Chi-square test and Cox proportional hazard analyses were performed.

RESULTS

Preoperatively, 64 patients had ALL injuries (53.3%), 58 had medial meniscal (MM) tears (48.3%), and 62 had lateral meniscal (LM) tears (51.6%). Ninety-three patients (77.5%) had acute injuries and 27 had chronic injuries as per 6-weeks duration. Significant risk factors for failure were LM tear (hazard ratio [HR], 4.018; 95% confidence interval [CI] 1.677-9.629; p = 0.002), chronicity (HR, 6.812; 95% CI 2.758-16.824; p = 0.000), presence of ALL injury (HR, 3.655; 95% CI 1.442-9.265; p = 0.006), and poor synovialization (HR, 3.134; 95% CI 1.298-7.566; p = 0.011) in Cox proportional hazard analysis. If combined MM and LM tears were found, an increased risk of failure was also identified (combined tears: HR, 3.951; 95% CI 1.754-8.901; p = 0.001/preoperative high-grade laxity: HR, 4.546; 95% CI 1.875-11.02; p = 0.001).

CONCLUSION

Chronic ACL injuries, meniscus tear, preoperative ALL injuries, preoperative high-grade laxity and poor synovialization are significant risk factors. Therefore, these factors should be carefully assessed and properly treated in TT ACL reconstruction.

LEVEL OF EVIDENCE

IV, retrospective cohort study.

Anterior Cruciate Ligament Reconstruction Within 3 Weeks Does Not Increase Stiffness and Complications Compared With Delayed Reconstruction: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Injury-to-surgery time has been identified as a key point in anterior cruciate ligament (ACL) reconstruction, with early versus delayed treatment remaining a debated and controversial topic in the management of ACL tears.

PURPOSE/HYPOTHESIS

The aim was to quantitatively synthesize the best literature evidence by including only randomized controlled trials (RCTs) comparing early versus delayed ACL reconstruction, with a clear and univocal definition of cutoffs of early or delayed surgery. The hypothesis was that early treatment would lead to similar final clinical results compared with the delayed approach while providing a faster recovery without an increase in complications after ACL reconstruction.

STUDY DESIGN

Meta-analysis.

METHODS

A systematic literature search was performed on February 12, 2019, using PubMed, Web of Science, Cochrane Library, and gray literature databases. According to previous literature, 2 analyses with different cutoffs for injury-to-surgery time (3 weeks and 10 weeks) were performed to distinguish early and delayed reconstruction. The influence of timing was analyzed through meta-analyses in terms of patient-reported outcome measures (PROMs), risk of complications, range of motion (ROM) limitation, risk of retears, and residual laxity. Risk of bias and quality of evidence were assessed following the Cochrane guidelines.

RESULTS

Eight studies (5 in 3-week cutoff analysis and 3 in 10-week cutoff analysis) were included. No differences were found in terms of PROMs, risk of complications, ROM limitation, risk of retears, and residual laxity either in the 3-week cutoff analysis or in the 10-week cutoff analysis (P > .05). The level of evidence was moderate to low for the outcomes of the 3-week cutoff analysis and low to very low for the outcomes of the 10-week cutoff analysis.

CONCLUSION

This meta-analysis did not confirm the previously advocated benefits of delaying ACL surgery to avoid the acute posttraumatic phase. In fact, RCTs demonstrated that timing of surgery after ACL tears has no influence on the final functional outcome, risk of retears, or residual instability. While no data were available about the recovery time, literature results showed that early ACL reconstruction could be performed without increasing the risk of complications.

STUDY REGISTRATION

CRD42019119319 (PROSPERO).

[Artificial ligaments applied in anterior cruciate ligament repair and reconstruction: Current products and experience]

The application of artificial ligament products in anterior cruciate ligament (ACL) surgeries has gone through a long twisty way. In the 1970s, early artificial ligament products were initially used for ACL surgeries, which showed poor clinical efficacy and eventually ended up in failure. Over the last 20 years, there has been a growing number of ACL reconstruction with new artificial ligament products, including the Leeds-Keio TM, the LARS TM (Ligament Advanced Reinfocement System), and the Trevira Hochfest TM. Among these new products, the LARS TM has been more commonly applied for ACL surgeries. Although these new artificial ligament products have good mechanical properties and show significant improvement of cumulative failure and complication rate, they still have limitations.

Impact of Surgical Timing on Clinical Outcomes in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts

Background:

To date, no studies have analyzed the influence on clinical outcomes of the interval between an anterior cruciate ligament (ACL) injury and double-bundle (DB) reconstruction with hamstring tendon autografts.

Hypotheses:

(1) Performing ACL reconstruction sooner after an injury will reduce postoperative anterior and rotatory knee instability, (2) postoperative range of knee motion or functional results will not be affected by different intervals between injury and surgery, and (3) preoperative isokinetic peak torque of the quadriceps and hamstring muscles will be lower in patients undergoing surgery earlier, while postoperative muscle strength will not be affected by surgery timing.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This study was conducted on a total of 171 patients who had undergone anatomic DB ACL reconstruction with hamstring tendon autografts. The patients were divided into 3 groups based on the time to surgery: (1) ≤1 month after the injury (group E; n = 25), (2) between 1 and 3 months after the injury (group M; n = 72), and (3) >3 months after the injury (group D; n = 74). Patients were assessed for a minimum of 2 years after surgery.

Results:

Concerning postoperative anterior laxity, 1-way analysis of variance demonstrated a significant difference (P = .0274) among the 3 groups. Anterior laxity was significantly less in group E than in group D (P = .0206). Spearman rank correlation analysis showed a significant correlation (ρ = 0.200; P = .0327) between anterior knee laxity and time to surgery. Also, a significant correlation (P = .0461) was found between the degree of the pivot-shift phenomenon and time to surgery. There were no significant differences in loss of knee extension or flexion among the 3 groups, nor were there any differences in the Lysholm knee score or International Knee Documentation Committee grade. Postoperatively, there were no significant differences in peak torque of the quadriceps or hamstring muscles among the 3 groups.

Conclusion:

Early DB reconstruction led to significantly less anterior laxity compared with delayed reconstruction. There were no significant differences in postoperative range of knee motion or functional results among the 3 time intervals between injury and surgery in this study.

LARS synthetic ligaments for the acute management of 111 acute knee dislocations: effective surgical treatment for most ligaments

PURPOSE

The purpose of this study was to describe the longitudinal outcomes of acute repair and augmentation for the reconstruction of dislocated knees, using LARS synthetic ligaments.

METHODS

Patients with a knee dislocation surgically treated using LARS synthetic ligament augmentation, with a minimum follow-up of 24 months, were enrolled between 1996 and 2014. Range of motion, Lachman, pivot shift, posterior drawer, step off sign, valgus, varus, KT-1000 arthrometer, Telos technique, IKDC, Lysholm, Tegner, and Meyers scores were obtained every 2 years up to 10 years.

RESULTS

Median age was 32.1 years (IQR 23.2-43.3) at time of surgery. Median time from trauma to surgery was 9 days and mean follow-up time was 6.6 years. Median questionnaire scores were: Lysholm 79.5 (IQR 65.0-89.0), Tegner 4.0 (IQR 3.7-6.0), Meyers 3.0 (IQR 3.0-4.0), and mean IKDC was 63.8 (SD 18.9). Median flexion and extension of the injured knee was 124° (IQR 115-129.5) and 0° (IQR - 5 to 0), respectively. Median KT-1000 differential was 0.7 mm (IQR 0.1-3.1) for ACL and 0.9 mm (IQR 0.2-1.4) for PCL. Mean differential for Telos was 2.5 mm (SD 5.8) for ACL, 4 mm (IQR 2-6.3) for PCL 30°, and 8.2 mm (SD 4.4) for PCL 90° (consistent with PCL laxity). More than 90% of patients had good anterior articular stability and > 60% of patients had good posterior articular stability.

CONCLUSIONS

Acute repair and augmentation of knee dislocations with LARS synthetic ligaments resulted in satisfactory outcomes for the ACL and collateral structures. Telos stress radiography showed PCL laxity in more than half of cases despite low laxity results with KT-1000. The perception of patients about knee function was sustained in time.

LEVEL OF EVIDENCE

IV.

Passive anterior tibia translation in anterior cruciate ligament-injured, anterior cruciate ligament-reconstructed and healthy knees: a systematic review

Abstract

Anterior tibia translation (ATT) is mainly prevented by the anterior cruciate ligament. Passive ATT tests are commonly used to diagnose an anterior cruciate ligament (ACL) injury, to select patients for an ACL reconstruction (ACLR), and as an outcome measure after an ACLR. The aim of this review was to present an overview of possible factors determining ATT. A second purpose was to give a summary of the ATT measured in the literature in healthy, ACL-injured and ACLR knees and a comparison between those groups. A literature search was conducted with PubMed. Inclusion criteria were full-text primary studies published in English between January 2006 and October 2016. Studies included reported ATT in explicit data in healthy as well as ACL-injured or ACLR knees or in ACL-injured as well as ACLR knees. Sixty-one articles met inclusion criteria. Two articles measured the ATT in healthy as well as ACL-injured knees, 51 in ACL-injured as well as in ACLR knees, three in ACLR as well as in healthy knees and three in healthy, ACL-injured and ACLR knees. A difference in ATT is found between healthy, contralateral, ACLR and ACL-injured knees and between chronic and acute ACL injury. Graft choices and intra-articular injuries are factors which could affect the ATT. The mean ATT was lowest to highest in ACLR knees using a bone–patella tendon–bone autograft, ACLR knees using a hamstring autograft, contralateral healthy knees, healthy knees, ACLR knees with an allograft and ACL-injured knees. Factors which could affect the ATT are graft choice, ACL injury or reconstruction, intra-articular injuries and whether an ACL injury is chronic or acute. Comparison of ATT between studies should be taken with caution as a high number of different measurement methods are used. To be able to compare studies, more consistency in measuring devices used should be introduced to measuring ATT. The clinical relevance is that an autograft ACLR might give better results than an allograft ACLR as knee laxity is greater when using an allograft tendon.

Level of evidence

III.

The Long-Term Outcome After Early and Late Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare long-term clinical and radiographic outcomes in patients undergoing either early (group A) or late (group B) surgery after anterior cruciate ligament (ACL) injury.

METHODS

ACL reconstruction using hamstring tendon autografts was performed in 30 patients in group A (median age, 23 years; range, 17-49 years) and 31 patients in group B (median age, 27 years; range, 17-38 years). The patients in group A were operated on within 5 months (median, 3 months; range, 2-5 months) of injury, whereas those in group B were operated on more than 24 months (median, 30 months; range, 24-48 months) after injury. The follow-up period was 10 years (median, 117 months [range, 77-222 months] in group A and 129 months [range, 77-206 months] in group B; P = .44). Multiple objective clinical evaluation tests and patient-reported outcome measures were obtained preoperatively and at follow-up. At follow-up, radiographic assessments of knee osteoarthritis (OA) bilaterally were performed.

RESULTS

The frequency of meniscectomy at the index operation was significantly lower in group A (20%) than in group B (52%) (P = .01). There were no significant differences between the groups in terms of Tegner and Lysholm scores and laxity tests both preoperatively and at follow-up. Both groups improved over time in terms of Tegner and Lysholm scores (P < .05). At follow-up, significantly more medial-compartment OA in the index knee was found in group B than in group A (P = .037) according to the Ahlbäck classification system. The index knee showed significantly more OA than the contralateral knee in both groups (P < .01).

CONCLUSIONS

Patients who underwent early ACL reconstruction required significantly fewer meniscectomies at the index operation than patients who underwent late reconstruction and showed significantly less OA on the medial side of the knee 10 years after reconstruction. However, no significant differences were found between the groups in terms of clinical assessments.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Innovative, intra-articular, prosthetic technique for cranial cruciate ligament reconstruction in dogs: a cadaveric study

The purpose of this study was to describe and assess the feasibility of a new intra-articular approach in the treatment of cranial cruciate ligament deficiency in dogs using an artificial ligament and a new bone-anchor system. Twelve canine cadavers weighting 26 to 45 kg were used in this ex-vivo study. Special tibial and femoral screws, two helicoils, and a high resistance artificial fiber compose the implant. Surgery was performed using the cranio-lateral approach to the stifle joint. Helicoil and tibial screw, connected to the fiber, were inserted in the center of the tibial insertion area of the cranial cruciate ligament. The fiber was passed over-the-top, tensioned, and fixed to the femoral screw, previously inserted with the helicoil in the distal part of the femur. Surgery was completed in all the cases. Occasional problems found during the insertion of the helicoils and screws were resolved with simple procedures. Post-operative clinical assessment showed negative cranial drawer test, negative cranial tibial thrust, and normal range of motion. Radiographic evaluation showed an appropriate positioning of both tibial and femoral implants in all the cases. The results of the first surgical appraisal of this new technique are encouraging, although further studies are necessary to demonstrate the in vivo efficacy of this procedure.

Effect of the Timing of Anterior Cruciate Ligament Reconstruction on Clinical and Stability Outcomes: A Systematic Review and Meta-analysis

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the effect of the timing of anterior cruciate ligament (ACL) reconstruction on clinical and stability outcomes by analyzing high-quality studies that assessed timing as a primary objective.

METHODS

The MEDLINE, EMBASE, and Cochrane database were systematically searched. The inclusion criteria were as follows: (1) English articles, (2) noncomparative study or relevant study reporting clinical and/or stability results, and (3) timing of the ACL reconstruction as a primary objective. Study type, level of evidence, randomization method, exclusion criteria, number of cases, age, sex, timing of ACL reconstruction, follow-up, clinical outcomes, stability outcomes, and other relevant findings were recorded. Statistical analysis of the Lysholm scores and KT-1000 arthrometer measurements after early and delayed ACL reconstruction was performed using R version 3.3.1.

RESULTS

Seven articles were included in the final analysis. There were 6 randomized controlled trials and 1 Level II study. Pooled analysis was performed using only Level I studies. All studies assessed the timing of ACL reconstruction as a primary objective. The definition of early ranged broadly from 9 days to 5 months and delayed ranged from 10 weeks to >24 months, and there was an overlap of the time intervals between some studies. The standard timing of the delayed reconstruction was around 10 weeks from injury in the pooled analysis. After pooling of data, clinical result was not statistically different between groups (I²: 47%, moderate level of heterogeneity). No statistically significant difference was observed in the KT-1000 arthrometer measurements between groups (I²: 76.2%, high level of heterogeneity) either.

CONCLUSION

This systematic review and meta-analysis performed using currently available high-quality literature provides relatively strong evidence that early ACL reconstruction results in good clinical and stability outcomes. Early ACL reconstruction results in comparable clinical and stability outcomes compared with delayed ACL reconstruction.

LEVEL OF EVIDENCE

Level II, a systematic review and meta-analysis of Level I and II studies.

Enhance the biocompatibility and osseointegration of polyethylene terephthalate ligament by plasma spraying with hydroxyapatite in vitro and in vivo

PURPOSE

This study was designed to evaluate the biocompatibility and osseointegration of polyethylene terephthalate ligament after coating with hydroxyapatite (PET/HA) by using the plasma spraying technique in vitro and in vivo.

METHODS

In this study, PET/HA sheets were prepared by using the plasma spraying technique. The characterization, the viability of bone marrow stromal cells (BMSCs), and the mRNA expression of bone formation-related genes were evaluated in vitro. The osseointegration in vivo was investigated in the rabbit anterior cruciate ligament (ACL) reconstruction model by micro-computed tomography (micro-CT) analysis, histological evaluation, and biomechanical tests.

RESULTS

Scanning electron microscopy (SEM) results showed that the surface of polyethylene terephthalate (PET) becomes rough after spraying with hydroxyapatite (HA) nanoparticles, and the water contact angle was 75.4°±10.4° in the PET/HA-plasma group compared to 105.3°±10.9° in the control group (p<0.05). The cell counting kit-8 counting results showed that the number of BMSCs significantly increased in the PET/HA-plasma group (p<0.05). Reverse transcription polymerase chain reaction (RT-PCR) results showed that there was an upregulated mRNA expression of bone formation-related genes in the PET/HA-plasma group (p<0.05). Micro-CT results showed that the transactional area of tibial tunnels and femoral tunnels was smaller in the PET/HA-plasma group (p<0.05). The histological evaluation scores of the PET/HA-plasma group were significantly superior to those of the PET control group at 8 and 12 weeks (p<0.05). The biomechanical tests showed an increased maximum load to failure and stiffness in the PET/HA-plasma group compared to those in the control group at 8 and 12 weeks.

CONCLUSION

Both in vitro and in vivo results demonstrated in this study suggest that the biocompatibility and osseointegration of PET/HA ligament were significantly improved by increasing the proliferation of cells and upregulating the expression of bone formation-related genes. In a word, the PET/HA-plasma ligament is a promising candidate for ACL reconstruction in future.

LARS™ in ACL reconstruction: evaluation of 60 cases with 5-year minimum follow-up

PURPOSE

The injury of anterior cruciate ligament (ACL) causes joint instability and, in the absence of adequate treatment, progressive joint deterioration, meniscal lesions and development of post-traumatic osteoarthritis.

METHODS

The purpose of this study was to evaluate the clinical, functional and radiographic outcomes and complications in a consecutive case series of 60 patients with minimum follow-up of 5 years who underwent an arthroscopic surgery for ACL reconstruction using LARS™ ligament. Patients with concomitant meniscal or chondral lesions in the same knee were excluded.

RESULTS

The subjective evaluation of the patients involved in the study (Lysholm score, IKDC score and Tegner activity level scale) shows good/excellent results. The range of movement is optimal in most patients, and pain symptoms are considered mild. A total of 31.25% of the patients did not change their lifestyle that they had before the injury. None of the patients underwent resurgery in the same knee. In 85.4% of cases, X-ray images showed no signs of osteoarthritis after ACL reconstruction.

CONCLUSIONS

Comparable with other series showed in the literature, this study assesses that the use of LARS™ in reconstruction of ACL is an excellent option for treating >40-year-old patients requesting rapid return to daily activities/sports also at the first surgery. By restoring knee stability, articular degeneration at short and medium follow-up was avoided.

Comparison of artificial graft versus autograft in anterior cruciate ligament reconstruction: a meta-analysis

BACKGROUND

Critically evaluation and summarization for the outcomes between autografts and artificial grafts using in anterior cruciate ligament (ACL) reconstruction have not been performed currently. The purpose of this study is to compare the clinical outcomes between artificial ligaments and autografts at a short- to mid-term follow-up.

METHODS

A computerized search of the databases was conducted including Medline, Embase, and the Cochrane library. Only prospective or retrospective comparative studies with a minimum 2-year follow-up and a minimum sample size of 15 for each group were considered for inclusion. Two independent reviewers performed data extraction and methodological quality assessment. A Mantel-Haenszel analysis was used for pooling of results. Sensitivity analysis was performed in order to maintain the stability of results.

RESULTS

Seven studies were included in this study. The total sample size was 403 (autograft group: 206 patients; synthetic graft group: 197 patients). Four studies were randomized controlled trials. Two studies were retrospective comparative studies and one study was non-randomized prospective comparative study. In terms of instrumented laxity, patient-oriented outcomes and complications, no significant difference was occurred between new artificial ligaments and autografts. But the results of IKDC grades and instrumented laxity were worsen in early artificial ligaments compared to autografts.

CONCLUSIONS

The outcomes of new generation of artificial ligaments are similar to autografts at a short- to mid-term follow-up. However, the early artificial ligaments are not suggested for ACL reconstruction compared to autografts.

Use of Estradiol Promotes Graft-Bone Healing in Rabbit Model of Anterior Cruciate Ligament Reconstruction With a Polyethylene Terephthalate Ligament

The purpose of this study was to investigate whether the local use of estradiol after anterior cruciate ligament (ACL) reconstruction with a polyethylene terephthalate (PET) artificial ligament graft could promote graft-bone healing. A total of 45 New Zealand white rabbits underwent ACL reconstruction with a PET ligament graft. The experimental groups were administered a local estradiol injection at either a low dose after surgery or a high dose after surgery, and the control group did not receive an injection. Computed tomography (CT) scans and blood sample collection were routinely performed in all three groups. Over time, the serum estradiol levels increased in both experimental groups, and the CT images revealed a trend of a shrinking bone tunnel area in all three groups. The rabbits were randomly sacrificed at 2, 4, and 8 weeks after surgery. The load to failure and stiffness of the experimental groups were significantly higher than those of the control group at 4 and 8 weeks. The histological study identified more bone mineralization in the experimental groups at 4 weeks after surgery compared to the control group. This study showed that the use of estradiol is a promising approach in promoting graft-bone healing in rabbits undergoing ACL reconstruction with a PET ligament graft.

Clinical outcomes of anterior cruciate ligament reconstruction using LARS artificial graft with an at least 7-year follow-up

The aim of our study was to assess the medium-term clinical outcomes of anterior cruciate ligament (ACL) reconstruction using the Ligament Advanced Reinforcement System (LARS) artificial ligament.A total of 168 patients who underwent arthroscopic ACL reconstruction with the LARS artificial ligament in our department were enrolled in our research. Only 125 met the inclusion/exclusion criteria, and 91 could ultimately be contacted to participate in our research. The mean follow-up was 92 ± 19 months. Physical examinations and a KT-1000 arthrometer were used to evaluate knee laxity. The International Knee Documentation Committee (IKDC) and Lysholm knee scales were evaluated for knee function. The Tegner score was tested for the condition of return to sport. Range of motion (ROM) and the rates of failure and complications were calculated.Among all patients enrolled in the study, the failure rate was 4.4%, and the overall complication rate was 2.2%. Knee laxity measured by the KT-1000 arthrometer was 1.4 ± 1.5 mm, compared with the preoperative value of 5.1 ± 1.3 mm. The Lysholm score improved from a preoperative value of 54.6 ± 14.3 to a postoperative value of 85.4 ± 12.1. The proportion of return to sport was 86.8% (79/91). The postoperative Tegner score was 4.7 ± 1.3, while its value before injury was 5.5 ± 1.0.In this study, ACL reconstruction using the LARS artificial ligament has a good prognosis with a low failure and complication rate at a mean follow-up of 91 months.

An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 1: Clinical Tests Do Not Correlate With Return-to-Sport Outcomes

BACKGROUND

Additional high-quality prospective studies are needed to better define the objective criteria used in relation to return-to-sport decisions after synthetic (ligament advanced reinforcement system [LARS]) and autograft (hamstring tendon [2ST/2GR]) anterior cruciate ligament (ACL) reconstruction in active populations.

PURPOSE

To prospectively investigate and describe the recovery of objective clinical outcomes after autograft (2ST/2GR) and synthetic (LARS) ACL reconstructions, as well as to investigate the relationship between these clinimetric test outcomes and return-to-sport activity (Tegner activity scale [TAS] score) at 12 and 24 months postoperatively.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 64 patients who underwent ACL reconstruction (32 LARS, 32 2ST/2GR autograft) and 32 healthy reference participants were assessed for joint laxity (KT-1000 arthrometer), clinical outcome (2000 International Knee Documentation Committee [IKDC] knee examination), and activity (TAS score) preoperatively and at 12, 16, 20, and 24 weeks and 12 and 24 months postoperatively.

RESULTS

There was no significant correlation observed between clinical results using the 2000 IKDC knee examination and TAS score at 24 months (r_s = 0.188, P = .137), nor were results for side-to-side difference (r_s = 0.030, P = .814) or absolute KT-1000 arthrometer laxity of the surgical leg at 24 months postoperatively (r_s = 0.076, P = .553) correlated with return-to-sport activity. Nonetheless, return-to-sport rates within the surgical cohort were 81% at 12 months and 83% at 24 months, respectively. No statistically significant differences were observed between physiological laxity of the uninjured knee within the surgical group compared with healthy knees within the reference group (P = .522).

CONCLUSION

The results indicate that although relatively high levels of return-to-sport outcomes were achieved at 24 months compared with those previously reported in the literature, correlations between objective clinical tests and return-to-sport outcomes may not occur. Clinical outcome measures may provide suitable baseline information; however, the results of this study suggest that clinicians may need to place greater emphasis on other outcome measures when seeking to objectively promote safe return to sport.

ACL rupture and joint laxity progression: a quantitative in vivo analysis

PURPOSE

Benefits of an early reconstruction and the optimal time lapse between injury and surgery to reduce the effects of altered kinematics in ACL-deficient knees are still controversial.

AIM

The aim of this study was to clarify, through a quantitative in vivo evaluation, the effects of the time lapse between ACL injury and surgery in terms of changes in the pre-operative knee laxity.

METHODS

An in vivo study was performed on 99 patients who underwent ACL surgery. Just before the graft fixation, six laxity tests were performed for all the subjects at manual-maximum load: anterior-posterior displacement and internal-external rotation at 30° and 90° of knee flexion (AP30, AP90, IE30, IE90) as well as varus-valgus rotation (VV0, VV30) at 0° and 30° of flexion. Kinematics data were acquired by a navigation system. The Spearman rank correlation was used to assess correlation between rank and continuous data. Significance was set at P = 0.05.

RESULTS

The analysis highlighted a significant influence of the injury-to-surgery time lapse on VV0 and AP90 compared with pre-operative laxity levels. Meniscus status also significantly affected the pre-operative laxity in the VV0 (Spearman's ρ = 0.203, P = 0.038; GLM with meniscal correction partial η = 0.27, P = 0.007) and AP90 (Spearman's ρ = 0.329, P = 0.001; GLM with meniscal correction partial η = 0.318, P = 0.017) tests.

CONCLUSION

The main finding of this study is that patients with ACL rupture and a higher injury-to-surgery time present higher values of knee laxity involving AP90 displacement and VV30 rotation. Clinical relevance of the study is that ACL-deficient joint laxity, involving anterior-posterior displacement at 90° of knee flexion and varus-valgus rotation at 0° of flexion, is significantly affected by the lapse of injury-to-surgery time. This highlights the importance of considering the effects of delaying surgery when managing patients with such deficiency.

Effects of Artificial Ligaments with Different Porous Structures on the Migration of BMSCs

Polyethylene terephthalate- (PET-) based artificial ligaments (PET-ALs) are commonly used in anterior cruciate ligament (ACL) reconstruction surgery. The effects of different porous structures on the migration of bone marrow mesenchymal stem cells (BMSCs) on artificial ligaments and the underlying mechanisms are unclear. In this study, a cell migration model was utilized to observe the migration of BMSCs on PET-ALs with different porous structures. A rabbit extra-articular graft-to-bone healing model was applied to investigate the in vivo effects of four types of PET-ALs, and a mechanical test and histological observation were performed at 4 weeks and 12 weeks. The BMSC migration area of the 5A group was significantly larger than that of the other three groups. The migration of BMSCs in the 5A group was abolished by blocking the RhoA/ROCK signaling pathway with Y27632. The in vivo study demonstrated that implantation of 5A significantly improved osseointegration. Our study explicitly demonstrates that the migration ability of BMSCs can be regulated by varying the porous structures of the artificial ligaments and suggests that this regulation is related to the RhoA/ROCK signaling pathway. Artificial ligaments prepared using a proper knitting method and line density may exhibit improved biocompatibility and clinical performance.