Knee Anterior Cruciate Ligament Injuries

MiR-6924-5p-rich exosomes derived from genetically modified Scleraxis-overexpressing PDGFRα(+) BMMSCs as novel nanotherapeutics for treating osteolysis during tendon-bone healing and improving healing strength

Osteolysis at the tendon-bone interface can impair pullout strength during tendon-bone healing and lead to surgery failure, but the effects of clinical treatments are not satisfactory. Mesenchymal stem cell (MSC)-derived exosomes have been used as potent and feasible natural nanocarriers for drug delivery and have been proven to enhance tendon-bone healing strength, indicating that MSC-derived exosomes could be a promising therapeutic strategy. In this study, we explored Scleraxis (Scx) dynamically expressed in PDGFRα(+) bone marrow-derived mesenchymal stem cells (BMMSCs) during natural tendon-bone healing. Then, we investigated the role of PDGFRα(+) BMMSCs in tendon-bone healing after Scx overexpression as well as the underlying mechanisms. Our data demonstrated that Scx-overexpressing PDGFRα(+) BMMSCs (BMMSC^Scx) could efficiently inhibit peritunnel osteolysis and enhance tendon-bone healing strength by preventing osteoclastogenesis in an exosomes-dependent manner. Exosomal RNA-seq revealed that the abundance of a novel miRNA, miR-6924-5p, was highest among miRNAs. miR-6924-5p could directly inhibit osteoclast formation by binding to the 3'-untranslated regions (3'UTRs) of OCSTAMP and CXCL12. Inhibition of miR-6924-5p expression reversed the prevention of osteoclastogenic differentiation by BMMSC^Scx derived exosomes (BMMSC^Scx-exos). Local injection of BMMSC^Scx-exos or miR-6924-5p dramatically reduced osteoclast formation and improved tendon-bone healing strength. Furthermore, delivery of miR-6924-5p efficiently inhibited the osteoclastogenesis of human monocytes. In brief, our study demonstrates that BMMSC^Scx-exos or miR-6924-5p could serve as a potential therapy for the treatment of osteolysis during tendon-bone healing and improve the outcome.

Full recovery of near complete tear of anterior cruciate ligament without surgery: a case report

INTRODUCTION

The anterior cruciate ligament (ACL) is the region where spraining or tearing is most prevalent when the knee is injured. Complete ACL ruptures have a much less favorable outcome without surgical intervention. Polydeoxyribonucleotide (PDRN) is a relatively safe substance widely used for regenerative therapy.

PATIENT CONCERNS

A 43-year-old female patient visited our clinic with Rt. knee pain after slipping, which she rated as 7/10 on a numeric rating scale.

DIAGNOSIS

She was diagnosed as having a near complete tear of the ACL at the femoral attachment, partial tear of the lateral collateral ligament.

INTERVENTIONS

Ultrasound-guided PDRN injections were carried out 5 times at intervals of about 2 weeks.

OUTCOMES

At 3-month follow-up, the patient demonstrated an improvement in knee symptoms (numeric rating scale 0) and ROM without any complications. Even after 2 years and 5 months since the diagnosis, she has been doing her daily life well without any pain.

CONCLUSION

This is the first report of successful PDRN injection for near complete tear of ACL and partial tear of lateral collateral ligament without surgery.

Improving Maximal Strength in the Initial Postoperative Phase After Anterior Cruciate Ligament Reconstruction Surgery: Randomized Controlled Trial of an App-Based Serious Gaming Approach

Background

Anterior cruciate ligament reconstruction surgery is one of the most common orthopedic procedures. One of the main factors that influence the outcome is regaining strength in the postoperative phase. Because anterior cruciate ligament reconstruction surgeries are often performed in young patients, we combined the concept of prehabilitation with an app-based serious gaming approach to improve maximal strength postoperatively.

Objective

Our objective was to conduct a prospective randomized trial to evaluate whether an app-based active muscle training program (GenuSport Knee Trainer) can improve postoperative strength by starting rehabilitation immediately after primary anterior cruciate ligament reconstruction surgery.

Methods

We designed a pilot study in which we randomly assigned patients receiving primary anterior cruciate ligament reconstruction to either the serious gaming training (intervention) group or a conventional rehabilitation (control) group. Except for the serious gaming-based training, both groups followed the same postoperative treatment protocol. Outcome parameters were absolute and relative change in maximal strength, as well as the International Knee Documentation Committee Subjective Knee evaluation form, Knee Injury and Osteoarthritis Outcome Score, and Lysholm Knee Score.

Results

In total 26 patients agreed to participate (14 patients in the intervention group and 12 patients in the control group, 1 of whom was lost to follow-up). We noted a difference in absolute maximum strength between the exergaming intervention and the control groups. Mean maximum strength preoperatively was 155.1 (SD 79.2) N in the intervention group (n=14) and 157.0 (SD 40.8) N in the control group (n=11). Postoperative mean maximum strength was 212.8 (SD 78.5) N in the intervention group and 154.5 (SD 27.1) N in the control group. Mean absolute change in maximum strength was 57.7 (SD 95.2) N in the intervention group and –4.8 (22.2) N in the control group. The analysis of covariance model with absolute change as the dependent variable and treatment group and baseline maximum strength as covariates showed a relevant difference in relative change between treatment groups (intervention – control) of 59.7 N (95% CI 10.1-109.3; P=.02). Similarly to the absolute increase, the relative change in maximum strength was relevantly higher in the exergaming group. The mean relative change in maximum strength was 1.7 (SD 1.17) in the intervention group and 1 (SD 0.13) in the control group. No adverse events or problems were reported during the study period.

Conclusions

Implementation of an app-based active muscle training program in the early postoperative therapy scheme was associated with an improvement in maximal strength. Therefore, we considered the use of GenuSport training after anterior cruciate ligament reconstruction to be a helpful complement to rehabilitation after anterior cruciate ligament reconstruction surgery to improve strength in the early postoperative phase. To our knowledge this was the first study to analyze immediate postoperative serious gaming-based training with the GenuSport device based on strength improvement.

Anterior cruciate ligament reconstruction-related patient injuries: a nationwide registry study in Finland

Background and purpose - Treatment outcomes of anterior cruciate ligament (ACL) injuries are generally good, but complications after ACL reconstruction (ACLR) can result in long-lasting problems. Patient injury claims usually fall on the more severe end of the complication spectrum. They are important to investigate because they may reveal the root causes of adverse events, which are often similar regardless of the complication's severity. Therefore, we analyzed ACL-related patient injuries in Finland, the reasons for these claims, causes of complications, and grounds for compensation.Patients and methods - We analyzed all claims filed at the Patient Insurance Centre (PIC) between 2005 and 2013 in which the suspected patient injury occurred between 2005 and 2010. This study also reviewed all original patient records and available imaging studies. General background data were obtained from the National Care Register for Social Welfare and Health Care (HILMO).Results - There were 248 patient injury claims, and 100 of these were compensated. Compensated claims were divided into 4 main categories: skill-based errors (n = 46), infections (n = 34), knowledge-based errors (n = 6), and others (n = 14). Of the compensated skill-based errors, 34 involved graft malposition, 26 of them involved the femoral-side tunnel. All compensated infections were deep surgical site infections (DSSI).Interpretation - This is the first nationwide study of patient injuries concerning ACLRs in Finland. The most common reasons for compensation were DSSI and malposition of the drill tunnel. Therefore, it would be possible to decrease the number of serious complications by concentrating on infection prevention and optimal surgical technique.

The Fertilized Anterior Cruciate Ligament: An All-Inside Anterior Cruciate Ligament Reconstruction Augmented With Amnion, Bone Marrow Concentrate, and a Suture Tape

There is increasing research and interest surrounding biologics and sports medicine. Amnion has the potential to decrease adhesions and possibly protect anterior cruciate ligament (ACL) grafts along with increasing vascularization by acting as a scaffold. Bone marrow concentrate containing mesenchymal stem cells combined with Allosync Pure (Arthrex, Naples, FL) injected into ACL tunnels has the potential to increase the speed and quality of graft bone incorporation, especially when used in the setting of a soft-tissue allograft. Using suture tape augmentation (InternalBrace; Arthrex) with the reconstruction has been thought to increase the early strength of the reconstruction. In this article, we combine all 3 techniques into an all-inside ACL reconstruction that has great potential for an earlier return to play and advanced rehabilitation.

Factors Associated With a Delay in Achieving Full Knee Extension Before Anterior Cruciate Ligament Reconstruction

Background:

Arthrofibrosis commonly occurs after an acute anterior cruciate ligament (ACL) injury and following ACL reconstruction and can lead to poor outcomes. Preoperative stiffness has been shown to be associated with postoperative stiffness; however, few studies have examined predictors of preoperative delay in obtaining full knee extension.

Purpose:

To examine demographic and injury factors as predictors of time required to achieve full knee extension preoperatively in patients with an acute ACL injury.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 172 patients with an acute ACL tear at presentation (defined as ≤3 weeks from injury) who underwent magnetic resonance imaging (MRI) within 6 weeks of the injury were included in this analysis. Preoperative data included date of injury, age at injury, sex, body mass index, mechanism of injury (noncontact/contact), time from injury to surgery (days), time to achieve full extension prior to surgery (weeks), and bone bruising on MRI. Time to achieve full extension was categorized as <3 or ≥3 weeks. Unadjusted and adjusted logistic regression was used to examine predictors of delayed time to achieve full extension (≥3 vs <3 weeks). Odds ratios and 95% CIs were reported.

Results:

Time to achieve full extension was early (<3 weeks) in 98 patients and delayed (≥3 weeks) in 74 patients. The average time to achieve full extension was 7 days in the early group and 32.5 days in the delayed group. Delayed time to achieve full extension was associated with increased lateral femoral condyle (LFC) bruising compared with early time to achieve extension (82.8% vs 66.7%, respectively; P = .03). No other statistically significant predictors were found after adjustment for age, sex, body mass index, and mechanism of injury.

Conclusion:

Acute ACL injuries associated with LFC bone bruising seen on MRI are more likely to result in reduced extension prior to ACL reconstruction. These injuries should be identified and addressed by an appropriate preoperative rehabilitation program, and surgery should be delayed to avoid risking arthrofibrosis postoperatively by reconstructing a knee with less than full extension.