Current Trends in Anterior Cruciate Ligament Reconstruction: A Review

The Statistical Fragility of Lateral Extra-articular Tenodesis Research: A Systematic Review

Background

A P value of <.05 is often used to denote statistical significance; however, in many scenarios, this threshold is vulnerable to a small number of outcome reversals. This study joins a body of studies within the orthopaedic literature that evaluate the statistical fragility of existing research via metrics such as fragility index (FI) and fragility quotient (FQ).

Purpose/Hypothesis

The purpose of this study was to investigate the statistical fragility of randomized controlled trials (RCTs) and comparative studies on the topic, given the resurgent interest in lateral extra-articular tenodesis (LET) to augment primary or revision anterior cruciate ligament reconstruction (ACLR). It was hypothesized that the outcomes reported in these studies would be statistically fragile.

Study Design

Systematic review; Level of evidence, 4.

Methods

Comparative studies and RCTs regarding LET as an adjunct procedure to ACLR published between 2000 and 2022 were analyzed. Descriptive characteristics, dichotomous outcomes, and continuous outcomes were extracted. The FI and continuous FI (CFI) were calculated by the number of event reversals to change significance; the FQ and continuous FQ (CFQ) were calculated to normalize the fragility metrics per sample size.

Results

Of 455 studies screened, 29 studies were included (9 RCTs, 20 comparative); 79.3% of included studies were published after 2020. A total of 48 dichotomous and 265 continuous outcomes were analyzed. The median FI was 9.0 (IQR, 7.0-13.3), with FQ of 0.1 (IQR, 0.04-0.17); the median CFI was 7.8 (IQR, 4.2-19.6), with CFQ of 0.12 (IQR, 0.08-0.19). The FQ and CFQ for studies on LET with revision ACLR were larger (0.117 and 0.113, respectively) than those focused on primary ACLR (0.042 and 0.095, respectively).

Conclusion

Studies focused on LET with primary ACLR were more fragile than those on LET with revision, which suggests that further research on the indications for LET with primary ACLR is necessary. Future orthopaedic comparative research should include fragility metrics alongside traditional P values.

Graft Suturing Method Affects on Graft Diameter in Hamstring-Based Anterior Cruciate Ligament Reconstruction

INTRODUCTION

 Various benefits of needleless suture loop techniques in anterior cruciate ligament reconstruction graft preparation have been discussed, yet their impact on graft diameter remains unexplored. We hypothesized that the suture loop technique would reduce the graft diameter compared to the conventional locking suture technique.

METHODS

 Fifty-seven patients whose grafts were made with the Krackow stitch (group K) and 54 patients with the suture loop (group SL) were analyzed retrospectively. (1) The distal (sutured side) diameter of each anteromedial bundle and posterolateral bundle was compared to the proximal (non-sutured side) diameter, and (2) the average of the proximal and distal graft diameters in each group was calculated.

RESULTS

 In group K, 78.9% of anteromedial bundles and 40.3% of posterolateral bundles exhibited a larger distal diameter than the proximal, while in group SL, 42.6% of anteromedial bundles and 3.7% of posterolateral bundles showed a larger distal diameter. In both bundles, there were significantly fewer grafts with larger distal diameters in group SL (p < 0.001). The mean distal diameter of anteromedial bundles was smaller in group SL (6.33 ± 0.43 mm vs. 6.07 ± 0.43 mm, p < 0.005). Consequently, the distal cross-sectional area of anteromedial bundles in group SL was 8% smaller than that in group K.

CONCLUSION

 The use of the suture loop technique resulted in a significantly smaller distal diameter of the anteromedial bundle. This reduces the size of the tibial tunnel and may contribute to a reduction in potential damage to adjacent structures.

Internal brace augmentation reconstruction versus standard anterior cruciate ligament reconstruction: a randomised controlled clinical trial study protocol

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries in sports, and the gold standard for treating ACL rupture is tendon graft reconstruction. Internal brace technology is being used nowadays for ligament repair; however, more relevant in vivo clinical evidence is required for using internal brace technology in ACL reconstruction (ACLR). We conducted a randomised controlled trial to investigate the clinical efficacy of internal brace technology in ACLR.

METHODS AND ANALYSIS

This randomised, parallel-controlled trial included patients with ACL rupture who underwent inpatient surgery at the Department of Orthopaedics, Xiangya Hospital, Central South University. Random number table method was used to assign the participants to either the test or the control group. The test group underwent ACLR using the internal brace technique, whereas the control group underwent standard ACLR. Uniform postoperative rehabilitation protocol was used for both the groups. Patient-reported outcomes included preoperative baseline and postoperative recovery at 1, 3, 6, 12 and 24 months. The primary outcome was International Knee Documentation Committee function from baseline (ACL rupture) to 6 months postoperatively. Secondary outcomes included (1) other patient outcome reporting metrics, Lysholm knee score, Knee Injury and Osteoarthritis Outcome Score and Visual Analog Scale; (2) the use of Kneelax3 knee stabiliser to assess knee stability; (3) occurrence of adverse events, such as graft refraction or symptomatic instability, postoperative infection and contralateral injury and (4) magnetic resonance images at 12 and 24 months after ACLR.

ETHICS AND DISSEMINATION

This trial was approved by the Medical Ethics Committee of the Xiangya Hospital of Central South University on 26 October 2021. Data will be published in peer-reviewed journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200057526.

Graft failure within 2 years of isolated anterior cruciate ligament reconstruction is associated with increased risk of secondary meniscus tears

PURPOSE

A debilitating complication following anterior cruciate ligament reconstruction is a secondary meniscus tear. Currently, the literature is mixed regarding the risk factors associated with the incidence of secondary meniscus tears. The aim of this study was to investigate risk factors associated with meniscus tears following an isolated primary anterior cruciate ligament reconstruction. ACL graft failure was hypothesized to be the strongest risk factor for secondary meniscal injury occurrence.

METHODS

A retrospective cohort analysis was performed using the PearlDiver Database. Patients with a primary anterior cruciate ligament reconstruction were identified in the database. Patients with concomitant knee ligament injury or meniscus injury present at the time the index procedure were excluded. Patients were grouped to those who had a secondary meniscus tear within 2 years following anterior cruciate ligament reconstruction and those who did not. Univariate analysis and multivariable regression analysis was conducted to identify significant risk factors for a secondary meniscus tear.

RESULTS

There were 25,622 patients meeting criteria for inclusion in this study. Within 2 years from the primary anterior cruciate ligament reconstruction, there were 1,781 patients (7.0%) that experienced a meniscus tear. Graft failure had the highest odds of having a postoperative meniscus tear within 2 years (OR: 4.1; CI 3.5-4.8; p < 0.002). Additional significant risk factors included tobacco use (OR: 2.0; CI 1.0-3.1; p < 0.001), increased Charlson Comorbidity Index (OR: 1.2; CI 1.1-1.4), male gender (OR: 1.1; CI 1.1-1.2; p < 0.001), obesity (OR: 1.1; CI 1.1-1.2; p < 0.001), delayed surgery (OR:1.1; CI 1.1-1.2; p < 0.002), and patients age 30 and older (OR: 1.0; CI 1.0-1.0; p < 0.001).

CONCLUSIONS

This study found that anterior cruciate ligament graft failure is the strongest predictor of post-operative meniscus tears. Other risk factors, including tobacco use, increased CCI, male gender, obesity, delayed surgery, and age 30 and older, were established, with several being modifiable. Therefore, targeted preoperative optimization of modifiable risk factors and postoperative protocols may reduce the risk of secondary meniscus tears.

LEVEL OF EVIDENCE

Level III, prognostic trial.

The influence of body mass index on physical activity engagement following anterior cruciate ligament reconstruction: A systematic literature review

Background

The objective of this study was to summarize available literature that explored the impact of body mass index (BMI) on physical activity participation among individuals who were subjected to the anterior cruciate ligament reconstruction (ACLR).

Methods

A total of three electronic databases, including Web of Science, Scopus, and PubMed, were comprehensively searched to identify relevant investigations. The following inclusion criteria were applied: (1) study design was observational; (2) participants underwent the ACLR; (3) BMI was estimated as a predictor variable; and (4) outcomes evaluated referred to physical activity. The risk of bias was assessed with the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

Results

After a database search, 787 studies were found, and only 10 of them met each of the eligibility criteria and were included in the qualitative analysis. Regarding respondents' characteristics, 7171 individuals underwent ACLR, 4080 males and 3091 females, with a mean age of 25.5 years. Most importantly, the average BMI of the examined population was 24.9 kg/m2. In all studies, physical activity was evaluated subjectively using the Tegner activity scale and the Marx activity scale. The main findings unambiguously demonstrated that a negative relationship between BMI and physical activity engagement was observed. More specifically, there is convincing evidence that BMI over 25 kg/m2 harmfully affected subjectively assessed physical activity in individuals with a history of ACLR.

Conclusion

The results obtained in the presented research indicated that increased values of BMI were a factor that correlated with reduced physical activity levels in the ACLR population. Hence, taking into account the clinical and health implications of reduced physical activity participation, stimulation of a healthy lifestyle, such as a combination of adequately designed physical exercise and nutrition, seems necessary for the analyzed population.

The Risk Factors and Preventive Strategies of Poor Knee Functions and Osteoarthritis after Anterior Cruciate Ligament Reconstruction: A Narrative Review

Anterior cruciate ligament reconstruction (ACLR) is the standard surgical treatment for ACL injury, which typically uses a graft to replace the torn ligament in the knee that uses small incisions with minimally invasive surgery. The optimal knee functions following ACLR depend on rehabilitation processes before and after the surgery. Knee function is the ability of the knee to perform various types of functional movements like walking, squatting, running, jumping, and pivoting where patients expect to achieve maximum knee function or at least more than 80% of its initial condition before the injury to avoid being categorized as poor knee function after ACLR. Patients use patient-reported outcome measures to collect data on their health status and quality of life after ACLR. Post-traumatic osteoarthritis (PTOA) is a type of OA that manifests in local cartilage injury caused by chondrocyte death, and matrix dispersion occurs following a joint injury like ACL injury. Gender, time from injury to surgery, and graft type were considered as risk factors for poor knee function after ACLR, while overweight, meniscus tear, and cartilage defect as risk factors for PTOA. However, age is an internal risk factor for both poor knee function and PTOA following ACLR. This review suggests several strategies to prevent both conditions, including a pre-operative program, comprehensive rehabilitation, body weight control, and return to sport (RTS) consideration based on physical capacity, proper time, and psychological readiness.

The effects of weight bearing after ACL reconstruction on joint contracture in rats

PURPOSE

Joint contractures after anterior cruciate ligament (ACL) reconstruction are a serious problem. Given the uncertain effects of weight bearing after ACL reconstruction on contractures, this study was conducted to examine such effects.

MATERIALS AND METHODS

To control the amount of weight bearing, ACL-reconstructed rats were reared with either untreated (small weight bearing; weight bearing during locomotion was 54% of pre-surgery at minimum), hindlimb unloading (non-weight bearing), or sustained morphine administration (large weight bearing; weight bearing during locomotion was maintained at 80% or more of pre-surgery) conditions. Untreated rats were used as controls. Knee extension range of motions (ROMs) before (includes myogenic and arthrogenic factors) and after myotomy (includes arthrogenic factor only) and fibrotic reactions in the joint capsule were assessed 7 and 14 days post-surgery.

RESULTS

ACL reconstruction significantly reduced ROMs both before and after myotomy and induced fibrosis in the joint capsule accompanying upregulation of fibrosis-related genes (i.e., type I and III collagens and transforming growth factor-β1) at both time points. Morphine administration increased the ROM before myotomy, but not after myotomy 7 days post-surgery. Unloading after ACL reconstruction improved ROMs both before and after myotomy at both time points. In addition, unloading after ACL reconstruction attenuated fibrotic reactions in the joint capsule.

CONCLUSIONS

Our results suggest that morphine administration improves myogenic contractures in parallel with an increase in the amount of weight bearing. Unloading after ACL reconstruction is effective in reducing both myogenic and arthrogenic contractures.

Evaluation of biomechanical properties and biocompatibility: are partially absorbable cords eligible for anterior cruciate ligament reconstruction?

Introduction: Independent augmentation technology based on reinforcing devices has been reported to signifi-cantly reduce the elongation behavior of graft and improve knee stability after anterior cruciate ligament reconstruction (ACLR). Using biodegradable devices could reduce the risk of severe inflammatory reactions due to particle accumulation from foreign bodies. Given the limitations of the mechanical properties of biodegradable materials, partially biodegradable composite devices may offer a compromise strategy. Methods: Three types of partially absorbable core-sheath sutures, including low-absorbable cord (LA-C), medium-absorbable cord (MA-C) and high-absorbable cord (HA-C), were braided using unabsorbable ultra-high molecular weight polyethylene (UHMWPE) yarn and absorbable polydioxanone (PDO) monofil-ament bundle based on the desired configuration. The feasibility of these partially absorbable cords were verified by biomechanical testing, material degradation testing, and cell experiments, all performed in vitro. Results: Reinforcement of an 8 mm graft with the cords decreased dynamic elongation by 24%-76%, was positively related to dynamic stiffness, and increased the failure load by 44%-105%, during which LA-C showed maximum enhancement. Human ligament-derived fibroblasts showed good proliferation and vitality on each cord over 2 weeks and aligned themselves in the direction of the fibers, especially the UHMWPE portion. Discussion: This study supports the potential of partially degradable UHMWPE/PDO cords, particularly LA-C, for graft protection. Nervertheless, a higher proportion of biodegradable material results in lower stiffness, which may impair the protective and lead to mechanical instability during degradation.

Trends of Publications on Single- and Double-Bundle ACL Reconstructions over the Last 20 Years: A Bibliometric Analysis of the PubMed Literature

Purpose

To improve the clinical outcomes of anterior cruciate ligament reconstruction (ACLR), there have been attempts to reproduce anatomic reconstruction by modifying the single-bundle (SB) and double-bundle (DB) techniques. Although DB ACLR restores better rotational control compared to SB ACLR, it is still debatable whether there are higher clinical outcomes in favor of DB ACLR. We aimed to study the trends of publications on SB and DB ACLR techniques over the last 20 years.

Methods

For this bibliometric study, we performed a PubMed search on 31/05/2022 with a well-defined search strategy. The articles were downloaded into Excel software, and citations were determined from the iCite website for PubMed. The analysis was performed using SPSS software version 28.0.1. Data mining was performed using Orange software, Mac version 3.32.0, from the titles of all articles and each group of SB and DB ACLR. The output is presented as word clouds.

Results

A total of 10,530 publications were identified, of which 9699 publications (92.1%) pertained to SB-ACLR and 831 publications (7.9%) to DB-ACLR. There was a steady increase in the publications on SB-ACLR until 2012, followed by a steep increase that peaked in 2021. The highest number of publications on DB-ACLR was in 2012 (n = 76; 9.1%). The mean citations per year for SB-ACLR and DB-ACLR were 2.87 ± 4.31 and 2.74 ± 3.17, respectively. The most prolific journals publishing on this topic were Knee Surgery Sports Traumatology Arthroscopy, American Journal of Sports Medicine, and Arthroscopy. The top three articles that received the maximum number of citations were from Japanese authors.

Conclusion

The number of publications related to SB-ACLR was significantly higher than that related to DB-ACLR in the last 20 years. The publications related to DB-ACLR have decreased in the recent past, after reaching a peak in 2012. The citations per year of SB-ACLR and DB-ACLR were similar.

Bilateral Anterior Cruciate Ligament Reconstruction Using Gracilis and Semitendinosus Graft by Single-Staged Approach

A bilateral anterior cruciate ligament (ACL) tear is one of the rare injuries that is seen in orthopaedics practice. Although few single-staged bilateral ACL ruptures have also been documented, most bilateral ACL ruptures happen on two different occasions. Although there isn't a clear consensus, there have been accounts of both single-staged and two-staged reconstruction of bilateral ACL ruptures in the literature. This case report provides surgeons with options to consider while treating this unusual injury. A 35-year-old woman with bilateral anterior cruciate ligament injuries presented with an MRI of her left knee suggestive of a complete ACL tear with a Medial meniscus tear in the left knee, and an MRI of her right knee showed a complete ACL tear. The patient underwent arthroscopic ACL reconstruction in a single stage for both knees. Six months after her surgery, she had met all the rehabilitation goals and was cleared to resume her daily activities. The patient preoperatively had a visual analogue scale (VAS) score of 8, and postoperative assessment, her VAS score reduced to 2. ACL reconstruction in one stage and two stages were the surgical treatment modalities described in the literature. Concurrent rehabilitation of both ACL repairs is more economical, reduces hospital stay, and helps in early recovery, but it may result in severe quadriceps deconditioning. Double-staged surgeries are less demanding, with a shorter duration of surgery that can be performed by a less experienced surgeon. As single-staged bilateral ACL reconstruction is a less expensive option that reduces hospital stays and aids in early recovery for this rare patient population, it may be a great therapy option compared to two-staged bilateral ACL reconstruction.

Return to active duty after anterior cruciate ligament reconstruction (ACLR) in Chinese male military aircrews

Background

Surgically treated anterior cruciate ligament (ACL) injuries may be a waivable condition and allow return to full flight status, but waivers are based on expert opinion rather than recent published data. The purpose of this study was to evaluate return to flight after anterior cruciate ligament reconstruction (ACLR) in male military aircrews with ACL injuries and to identify factors that affect flight clearance.

Method

A single-center retrospective review was conducted by the authors for all active-duty aircrew who underwent ACLR at an authorized military medical center from January 2010 to December 2019. Demographic characteristics, occupational information, surgical data, and flight readiness evaluation outcomes were collected. Based on the final medical evaluation, subjects were divided into a qualified group (N = 64) and a disqualified group (N = 9), and the difference in data collected between the two groups was then analyzed to identify factors affecting flight clearance.

Results

A total of 73 patients underwent successful ACLR with a mean age of 31.6 ± 5.6 years. Non-contact injury was the main type of ACL injury, accounting for 84.9% of the total injuries. 55 cases (75.3%) occurred during daily sports activities and 18 (24.7%) during military training. 64 of the 73 crewmembers (87.7%) were able to return to flight at their last follow-up evaluation. The preoperative interval time (PIT) was significantly less in the qualified group than in the disqualified group (P = 0.002). Patients who underwent ACLR within three months were more likely to return to flying than those who underwent the procedure three months later (97.4% vs. 76.5%, P = 0.010). The incidence of failure to return to flight duty was significantly higher in aircrews with ACL injuries combined with meniscal injuries than in aircrews with isolated ACL injuries (21.4% vs. 0.0%, P = 0.017).

Conclusion

ACLR appears to be safe for military aircrew suffering ACL injuries with or without meniscal injury, and return to flight status is the most likely outcome for the majority of postoperative pilots. Prolonged PIT, PIT > 3 months, and ACL injury combined with meniscus injury had a negative impact on postoperative flight readiness.

Prevention of Secondary Injury after Anterior Cruciate Ligament Reconstruction: Relationship between Pelvic-Drop and Dynamic Knee Valgus

(1) Background: Optimal neuromuscular, Lumbo-Pelvic-Hip Complex, and lower extremity control are associated with decreased risk factors for secondary anterior cruciate ligament (ACL) injury. This study aimed to analyze any asymmetries and malalignments in the Lumbo-Pelvic-Hip Complex and the lower limbs at 6 months after ACL reconstruction (ACLR). (2) Methods: We conducted an exploratory retrospective observational single-center study in patients during the outpatient postoperative rehabilitation program at ICOT (Latina, Italy). From January 2014 to June 2020, 181 patients were recruited, but only 100 patients (86 male 28 ± 0.6 years, 178 ± 0.5 height; 14 female 24 ± 2.0 years, 178 ± 3.0 height) were eligible for the inclusion criteria and studied 6 months after ACL reconstruction surgery. (3) Statistical analysis: Student's t-tests and Pearson's product-moment correlation coefficient were used to determine significant differences between affected and non-affected limbs and variables' association. (4) Results: The study shows a decrease in neuromuscular control of the Lumbo-Pelvic-Hip Complex and dynamic adaptive valgus of the knee at 6 months after ACLR (mean difference between pathological and healthy limb of dynamic adaptive valgus was -10.11 ± 8.19° 95% CI -14.84 to -9.34; mean value was 16.3 ± 6.8° 95% CI 14.04 to 18.55 for healthy limb and 4.2 ± 3.1° 95% CI 3.15 to 5.21 for pathological limb, p < 0.0001). The results also showed a relationship between dynamic adaptive valgus and contralateral pelvic drop (r = 0.78, 95% CI 0.62 to 0.88, magnitude of correlation very large). (5) Conclusions: The analysis showed an associative correlation between decreased postural control of the pelvic girdle and dynamic adaptive valgus of the knee in 38% of patients; this study highlights the usefulness of the Single-Leg Squat Test (SLST) as a clinical/functional assessment to evaluate the rehabilitation process and as a preventive tool to reduce the risk of second ACL injuries during the return to sport.

Effects of Platelet-Rich Osteoconductive-Osteoinductive Allograft Compound on Tunnel Widening of ACL Reconstruction: A Randomized Blind Analysis Study

The anterior cruciate ligament (ACL) is a commonly injured ligament in the knee. Bone tunnel widening is a known phenomenon after soft-tissue ACL reconstruction and etiology and the clinical relevance has not been fully elucidated. Osteoconductive compounds are biomaterials providing an appropriate scaffold for bone formation such as a demineralized bone matrix. Osteoinductive materials contain growth factors stimulating bone lineage cells and bone growth. A possible application of osteoinductive/osteoconductive (OIC) material is in ACL surgery. We hypothesized that OIC placed in ACL bone tunnels: (1) reduces tunnel widening, (2) improves graft maturation, and (3) reduces tunnel ganglion cyst formation. To test this hypothesis, this study evaluated the osteogenic effects of demineralized bone matrix (DBM) and platelet-rich plasma (PRP) on tunnel widening, graft maturation, and ganglion cyst formation. This was a randomized controlled clinical trial pilot study. A total of 26 patients that elected to have ACL reconstruction surgery were randomized between the OIC and control group. Measurements of tunnel expansion and graft-tunnel incorporation were conducted via the quantitative image analysis of MRI scans performed at six months after surgery for both groups. No patients had adverse post-operative reactions or infections. The use of OIC significantly reduced tunnel widening (p < 0.05) and improved graft maturation (p < 0.05). Patients treated with OIC had a significantly lower prevalence of ganglion cyst compared to the control group (p < 0.05). The use of OIC has measurable effects on the reduction of tunnel widening, improved graft maturation, and decreased size of ganglion cyst after ACL reconstruction. This study explored the utilization of biologics to minimize bone tunnel widening in ACL reconstruction surgery.

The novel epiligament theory: differences in healing failure between the medial collateral and anterior cruciate ligaments

According to current literature, 90% of knee ligament injuries involve the medial collateral ligament or the anterior cruciate ligament. In contrast to the medial collateral ligament, which regenerates relatively well, the anterior cruciate ligament demonstrates compromised healing. In the past, there were numerous studies in animal models that examined the healing process of these ligaments, and different explanations were established. Although the healing of these ligaments has been largely investigated and different theories exist, unanswered questions persist.

Therefore, the aim of this article is 1) to review the different historical aspects of healing of the medial collateral ligament and present the theories for healing failure of the anterior cruciate ligament; 2) to examine the novel epiligament theory explaining the medial collateral ligament healing process and failure of anterior cruciate ligament healing; and 3) to discuss why the enveloping tissue microstructure of the aforementioned ligaments needs to be examined in future studies.

We believe that knowledge of the novel epiligament theory will lead to a better understanding of the normal healing process for implementing optimal treatments, as well as a more holistic explanation for anterior cruciate ligament healing failure.

Comparison of Bone-Patella Tendon-Bone and Four-Strand Hamstring Tendon Grafts for Anterior Cruciate Ligament Reconstruction: A Prospective Study

Introduction

To date, the proper choice of graft for anterior cruciate ligament (ACL) reconstruction remains a matter of conflict. We aimed to compare the clinical and functional outcomes of the two most commonly utilized autografts, bone-patella tendon-bone (BPTB) and four-strand hamstring tendon (HT) graft, at 6 and 12 months after surgery.

Methods

In a prospective randomized study, we included a total of 60 patients undergoing ACL reconstruction, thirty in BPTB and thirty in HT group. All patients were amateur athletes and were evaluated at 6 and12 months after surgery for: (a)postoperativefunctionality of the operated knee by the Tegner, the Lysholm and the International Knee Documentation Committee (IKDC) scoring scales, (b) anterior cruciate ligament (ACL) instability of the operated knee compared to the healthy contralateral knee by the KT-1000 arthrometer and (c) theextension and flexion muscle strength of the operated knee by a CYBEXisokinetic dynamometer. 

Results

Patients in the two groups did not differ regarding demographics, and pre-injury functionality status. Significantly more patients in the HT group (n=6) compared to the BPTB group (n=1) experienced ACL re-rupture and underwent revision surgery before follow-up end (p=0.044). All patients, regardless of graft, showed significant improvement within each group of functional assessments by Lysholm, Tegner and IKDC scores, as well as of Cybex measurements -with an increase of peak torque at 60° extension and 180°extension and 60° flexion and 180° flexion- at 12 months compared to 6 months follow-up (p<0.05). However, there was no difference between the two groups regarding knee function improvement or extension measurements neither at 6 nor 12 months. Contrarily, the BPTB graft group had higher values of peak torque (Nm) at 60° and 180° flexion compared to the HT group, both at 6 (p=0.014 and 0.029, respectively) and 12 months (p=0.033 and 0.030, respectively). Postoperative stability was similar between the two groups at 12 months (p=0.519).

Conclusion

Both BPTB and HT grafts present with benefits and drawbacks and remain viable autograft options for primary ACL reconstruction as each has, although HT grafts seem to be more susceptible to re-rupture. The graft selection should be based on the needs and activities of each patient. 

Polydopamine Coating-Mediated Immobilization of BMP-2 on Polyethylene Terephthalate-Based Artificial Ligaments for Enhanced Bioactivity

Background/objectives: Polyethylene terephthalate (PET)-based artificial ligaments are one of the most commonly used grafts in anterior cruciate ligament (ACL) reconstruction surgery. However, the lack of favorable hydrophilicity and cell attachment for PET highly impeded its widespread application in clinical practice. Studies found that surface modification on PET materials could enhance the biocompatibility and bioactivity of PET ligaments. In this study, we immobilized bone morphogenetic protein-2 (BMP-2) on the surface of PET ligaments mediated by polydopamine (PDA) coating and investigated the bioactivation and graft-to-bone healing effect of the modified grafts in vivo and in vitro.

Methods: In this study, we prepared the PDA coating and subsequent BMP-2-immobilized PET artificial ligaments. Scanning electron microscopy (SEM) was used to analyze the morphological changes of the modified grafts. In addition, the surface wettability properties of the modified ligaments, amount of immobilized BMP 2, and the release of BMP-2 during a dynamic period up to 28 days were tested. Then, the attachment and proliferation of rat bone mesenchymal stem cells (rBMSCs) on grafts were examined by SEM and Cell Counting Kit-8 (CCK-8) assay, respectively. Alkaline phosphatase (ALP) assay, RT-PCR, and Alizarin Red S staining were performed to test the osteoinduction property. For in vivo experiments, an extra-articular graft-to-bone healing model in rabbits was established. At 8 weeks after surgery, biomechanical tests, micro-CT, and histological staining were performed on harvested samples.

Results: A surface morphological analysis verified the success of the PDA coating. The wettability of the PET artificial ligaments was improved, and more than 80% of BMP-2 stably remained on the graft surface for 28 days. The modified grafts could significantly enhance the proliferation, attachment, as well as expression of ALP and osteogenic-related genes, which demonstrated the favorable bioactivity of the grafts immobilized with BMP-2 in vitro. Moreover, the grafts immobilized with BMP-2 at a concentration of 138.4 ± 10.6 ng/cm² could highly improve the biomechanical properties, bone regeneration, and healing between grafts and host bone after the implantation into the rabbits compared with the PDA-PET group or the PET group.

Conclusion: The immobilization of BMP-2 mediated by polydopamine coating on PET artificial ligament surface could enhance the compatibility and bioactivity of the scaffolds and the graft-to-bone healing in vivo.

Biomechanical analysis of three different types of fixators for anterior cruciate ligament reconstruction via finite element method: a patient-specific study

Complication rates of anterior cruciate ligament reconstruction (ACL-R) were reported to be around 15% although it is a common arthroscopic procedure with good outcomes. Breakage and migration of fixators are still possible even months after surgery. A fixator with optimum stability can minimise those two complications. Factors that affect the stability of a fixator are its configuration, material, and design. Thus, this paper aims to analyse the biomechanical effects of different types of fixators (cross-pin, interference screw, and cortical button) towards the stability of the knee joint after ACL-R. In this study, finite element modelling and analyses of a knee joint attached with double semitendinosus graft and fixators were carried out. Mimics and 3-Matic softwares were used in the development of the knee joint models. Meanwhile, the graft and fixators were designed by using SolidWorks software. Once the meshes of all models were finished in 3-Matic, simulation of the configurations was done using MSC Marc Mentat software. A 100-N anterior tibial load was applied onto the tibia to simulate the anterior drawer test. Based on the findings, cross-pin was found to have optimum stability in terms of stress and strain at the femoral fixation site for better treatment of ACL-R.

Numerical Analysis of the ACL, with Sprains of Different Degrees after Trauma

Nowadays, cruciate ligament injuries have increased in incidence, since practicing a sport or physical activity has become a trend in current societies. Although this lifestyle generates multiple benefits, as a consequence, injury has also increased. Due to its nature and complexity, the ligaments of the knee are those that are most frequently affected, mainly the ACL (anterior cruciate ligament). This tissue reacts to overexertion or movements out of range, either caused by the exercise itself or caused by trauma caused by the practice of physical activity, causing various degrees of sprain. Whatever the etiology of these injuries, they will require a therapy indicated for each degree of injury. This therapy initially entails immobilization of the affected area and later; physical therapy will be required to a lesser or greater degree. Commonly, in the physiotherapy of these injuries, rehabilitation exercises are prescribed, where the physiotherapist asks a patient to use equipment with an estimated weight. However, the effectiveness of a generalized therapy in this way does not always give the expected results. This is related to the fact that these therapies are standardized and do not consider some factors such as the remaining muscle fibres that are not directly affected by the sprain, which does not mean that they should not be considered. Therefore, in the present work, a biomodel of a human knee has been developed and used to evaluate numerically how the ACL acts under an external load, when there are different degrees of injuries, caused by trauma. Four case studies were considered: Case 1 (control case) where the ACL is healthy, Case 2 where the ACL presents a 1^st-degree sprain, Case 3 where the ACL presents a 2^nd-degree sprain, and finally Case 4 where the ACL presents a 3^rd-sprain grade. After performing the analyses, in the control case, it was found that it presents a balance between tensile and compressive stresses. While in the 4th case, the most critical tensile stress decreases while compression stresses increase. This shows that the ligament, having considerable damage, no longer works as it should and can eventually damage the collateral structures. It was found that, when there was a sprain, where the continuity of the ligament is compromised, a second torsional moment occurs in the ACL which causes the tissue fibres not to act according to their normal physiology or in a healthy state. The results obtained from the present study provide the possibility of predicting where the following injuries will occur by considering the von Mises failure criterion. Likewise, they will allow to improve the therapeutic procedures considering not only the injured structure but also the system as a whole.

Does radiological evaluation of endobutton positioning in the sagittal plane affect clinical functional results in single-bundle anterior cruciate ligament reconstruction?

INTRODUCTION

Sports injuries are increasing today due to the increased interest in sports. The most common injured knee ligament is the anterior cruciate ligament (ACL) in sport injuries. Accordingly, surgical treatment of the ACL is performed frequently. In this study, it was aimed to retrospectively evaluate whether the location of an endobutton on lateral knee radiography was effective on knee functional scores in patients who underwent ACL reconstruction.

MATERIALS AND METHODS

One hundred thirty patients who underwent ACL reconstruction between January 2015 and February 2019 were identified. The patients were divided into three groups according to the location of the endobutton on lateral radiographs taken in the postoperative period. Group 1 patients were classified as anterior, group 2 as middle, and group 3 as posterior according to the location of the endobutton. Functional scoring, physical examination tests, comparative thigh diameter measurements, and single-leg hop tests were compared between the groups. It was evaluated as to whether there was a statistically significant difference between the groups.

RESULTS

There were 38 patients in group 1, 63 patients in group 2, and 29 patients in group 3. The mean age was 29.1 in group 1, 29.1 in group 2, and 29.7 in group 3. The mean follow-up period of the patients was 18.4 months in group 1, 19.1 months in group 2, and 21.4 months in group 3. The average Lysholm score was 92.9 in group 1, 93.3 in group 2, and 91.7 in group 3. The mean modified Cincinnati scores were 27.0, 27.1, and 26.6, respectively, in the groups. The mean IKDC score of the subjective knee assessments was 92.5, 92.8, and 91, respectively, according to the groups. The average thigh atrophy value was 1 cm, 1 cm, and 1.2 cm, respectively, in the groups. In the single-leg hop test, 34 patients in group 1 jump to over 85% of the distance compared with the intact side, while 58 patients in group 2, and 23 patients in group 3 were successfully able to jump this distance. The effect of the placement of the endobutton in the anterior, middle or posterior was not statistically significant on functional scores and physical examination results. In patients with endobuttons in the middle, functional scores were found better than in those with anterior or posterior placement.

CONCLUSIONS

No statistically significant differences were found in clinical functional results when comparing patients' endobutton location on femur. For this reason, surgical time should not be extended using unnecessary extra effort to change the orientation of the exit hole during surgery.

Bone Mesenchymal Stem Cells Contribute to Ligament Regeneration and Graft-Bone Healing after Anterior Cruciate Ligament Reconstruction with Silk-Collagen Scaffold

Anterior cruciate ligament (ACL) reconstruction was realized using a combination of bone mesenchymal stem cells (BMSCs) and silk–collagen scaffold, and an in vivo evaluation of this combination was performed. By combining type I collagen and degummed silk fibroin mesh, silk–collagen scaffolds were prepared to simulate ligament components. BMSCs isolated from bone marrow of rabbits were cultured for a homogenous population and seeded on the silk–collagen scaffold. In the scaffold and BMSC (S/C) group, scaffolds were seeded with BMSCs for 72 h and then rolled and used to replace the ACL in 20 rabbits. In the scaffold (S) group, scaffolds immersed only in culture medium for 72 h were used for ACL reconstruction. Specimens were collected at 4 and 16 weeks postoperatively to assess ligament regeneration and bone integration. HE and immunohistochemical staining (IHC) were performed to assess ligament regeneration in the knee cavity. To assess bone integration at the graft–bone interface, HE, Russell–Movat staining, micro-CT, and biomechanical tests were performed. After 4 weeks, vigorous cell proliferation was observed in the core part of the scaffold in the S/C group, and a quantity of fibroblast-like cells and extracellular matrix (ECM) was observed in the center part of the graft at 16 weeks after surgery. At 4 and 16 weeks postoperatively, the tenascin-C expression in the S/C group was considerably higher than that in the S group (4 w, p < 0.01; 16 w, p < 0.01). Furthermore, bone integration was better in the S/C group than in the S group, with histological observation of trabecular bone growth into the graft and more mineralized tissue formation detected by micro-CT (4 w, bone volume fraction (BV/TV), p = 0.0169, bone mineral density (BMD), p = 0.0001; 16 w, BV/TV, p = 0.1233, BMD, p = 0.0494). These results indicate that BMSCs promote ligament regeneration in the knee cavity and bone integration at the graft–bone interface. Silk–collagen scaffolds and BMSCs will likely be combined for clinical practice in the future.

All-inside technique in ACL reconstruction: mid-term clinical outcomes and comparison with AM technique (Hamstrings and BpTB grafts)

PURPOSE

The aim of this study was to define the subjective and objective clinical results of all-inside surgical technique at a medium-term follow-up and to compare these results with those obtained from antero-medial (AM) ACL reconstruction technique using hamstrings (HS) or bone-patellar tendon-bone (BpTB) grafts to detect eventual superiority of one technique to another.

METHODS

A retrospective analysis of routinely collected data was conducted. Inclusion criteria were ACL reconstruction through all-inside technique or AM technique with HS or BpTB performed between January 2015 and May 2018; age between 15 and 30 year old; minimum 24 months' available follow-up. Exclusion criteria were contralateral ACL reconstruction; need for any other associated procedures during surgery. Clinical outcomes were assessed with KOOS, Lysholm, Tegner scores and KT-1000 device.

RESULTS

According to the selection criteria, 157 patients were enrolled and divided subsequently into 3 groups: all-inside (51 patients), AM-HS (53 patients) and AM-BpTB (53 patients). A significant postoperative improvement of each score in all groups was detected. The mean KT-1000 was 3.1 ± 1.0 mm in all-inside group, while 3.3 ± 1.4 mm and 2.5 ± 0.4 mm in AM-HS and AM-BpTB groups, respectively. Comparing the results obtained, no statistically significant difference was found between the three techniques (p = 0.27). Statistically significant differences were highlighted in surgical duration: all-inside method was the longest (117'), followed by AM-BpTB surgery (101') and AM-HS technique (87').

CONCLUSIONS

The all-inside technique showed good postoperative results at medium-term follow-up. It could be a valuable solution for ACL reconstruction, especially in young patients due to its less invasiveness, despite surgical skills and time needed.

LEVELS OF EVIDENCE

Level IV.

Femoral tunnel length has no correlation with graft rupture: A retrospective cohort study

BACKGROUND

Literature is controversial on femoral tunnel length as a risk factor for graft injury if the graft length in the tunnel is kept constant at ≥15 mm.

METHODS

A total of 1079 sportspersons, meeting our inclusion criteria, were assessed for graft rupture. Patients with femoral tunnel length (FTL) ≤30 mm were labeled as Group 1, while those with FTL > 30 mm were labeled as Group 2. Both groups were compared for potential risk factors for graft injury keeping graft length in the tunnel at ≥15 mm and statistical analysis was performed to study whether the femoral tunnel length acted as an additional risk factor.

RESULTS

Of 1079 sportspersons, 37 suffered from graft rupture. Patients with FTL > 30 mm were included in Group 1(n = 22) and patients with FTL ≤ 30 mm (n = 15) were included in Group 2. Both groups were comparable for risk factors for ACL injury: age (P = 0.37), gender (P = 0.53), mode of re-injury (P = 0.38), graft diameter (P = 0.71), level of sports activity (P = not significant), duration from injury to index surgery (P = 0.74), duration from index surgery to re-injury (P = 0.52), timing of return to sports after index surgery (P = 0.30), duration of sporting activity before second injury (P = 0.31), Tegner's level (P = not siginificant), Notch width index (P = 0.12) posterior slope (P = 0.77) and height (P = 0.41).

CONCLUSION

Because the graft length in the tunnel was kept at optimum and the risk factors for ACL injury were comparable in both groups at a follow up period, we suggest that femoral tunnel length is not a risk factor for graft failure.

Predictors for Anterior Cruciate Ligament (ACL) Re-injury after Successful Primary ACL Reconstruction (ACLR)

Introduction:

Few authors have addressed risk factors related to an ipsilateral graft rupture and contralateral anterior cruciate ligament (ACL) injury after return to sports (RTS) following primary ACL reconstruction.

Material and Methods:

Patients with ACL re-injury to either knee after successful primary ACLR were included in Group I and those with no further re-injury were included in Group II. Variables including age, gender, side, body mass index (BMI), thigh atrophy, anterior knee laxity difference between both knees measured by KT-1000 arthrometer, mean time of return to sports (RTS), graft type, type of game, mode of injury, Tegner Activity Score, hormone levels, femoral tunnel length (FTL), posterior tibial slope (PTS) and notch width index (NWI) were studied. Binary logistic regression was used to measure the relative association.

Results:

A total of 128 athletes were included with 64 in each group. Mean age in Group I and II were 24.90 and 26.47 years respectively. Mean follow-up of Group I and Group II were 24.5 and 20.11 months respectively. Significant correlation was present between ACL re-injury and following risk factors; PTS of >10º, KT difference of >3.0mm, thigh atrophy of >2.50cm and time to RTS <9.50 months P value <0.05). No correlation was found with age, sex, BMI, type of game, Tegner Activity Score, mode of injury, NWI, size of graft, FTL and hormone levels.

Conclusion:

Possible risk factors include PTS of ≥ 10º, KT difference of ≥ 3.0mm at 1 year follow-up, thigh atrophy of ≥ 2.50cm at 1 year follow-up and RTS <9.5 months after primary ACLR.

A Review on Finite Element Modeling and Simulation of the Anterior Cruciate Ligament Reconstruction

The anterior cruciate ligament (ACL) constitutes one of the most important stabilizing tissues of the knee joint whose rapture is very prevalent. ACL reconstruction (ACLR) from a graft is a surgery which yields the best outcome. Taking into account the complicated nature of this operation and the high cost of experiments, finite element (FE) simulations can become a valuable tool for evaluating the surgery in a pre-clinical setting. The present study summarizes, for the first time, the current advancement in ACLR in both clinical and computational level. It also emphasizes on the material modeling and properties of the most popular grafts as well as modeling of different surgery techniques. It can be concluded that more effort is needed to be put toward more realistic simulation of the surgery, including also the use of two bundles for graft representation, graft pretension and artificial grafts. Furthermore, muscles and synovial fluid need to be included, while patellofemoral joint is an important bone that is rarely used. More realistic models are also required for soft tissues, as most articles used isotropic linear elastic models and springs. In summary, accurate and realistic FE analysis in conjunction with multidisciplinary collaboration could contribute to ACLR improvement provided that several important aspects are carefully considered.

Bilateral Comparisons of Quadriceps Thickness after Anterior Cruciate Ligament Reconstruction

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48–72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb; RCL = Pre-operated (PRE): 19.89 ± 6.91 mm, Post-operated(POST): 16.04 ± 6.13 mm, Healthy limb; HL = PRE: 22.88 ± 6.07, POST: 20.90 ± 5.78 mm, F = 9.325, p = 0.009, η²p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR.

Clinico-radiological outcomes following anatomical anterior cruciate ligament reconstruction using the TransLateral, all-inside technique

We present early clinical outcomes of patients following anatomical anterior cruciate ligament reconstruction using a TransLateral, single bundle, all-inside technique with a one-year follow-up and radiological evaluation of socket position. Eligible Patients who underwent a primary ACL reconstruction, using the TransLateral, all-inside technique alone, between Jan 2013 and Feb 2016 were included in this study. Of this group, all patients underwent isolated semitendinosus graft harvest. The Lysholm knee scores were measured preoperatively and at one-year follow-up in 40 patients who underwent ACL reconstruction. Postoperatively, antero-posterior and lateral radiographs were obtained to evaluate the position of the femoral socket (using the Bernard and Hertel Grid) and tibial socket (using the Amis-Jakob line). There were 36 males and 4 females with a mean age of 27.1 years (range 16-49). There was a single non-surgical related mortality prior to the one year follow up. We report no postoperative infections or graft failure at one year. The mean preoperative Lysholm score was 68.7 (Range: 29-95). The mean Lysholm score increased to 92.5% (Range: 59-100, p < 0.05). Evaluation of femoral sockets revealed accurate positioning on the Bernard and Hertel Grid with a mean ACL center of 27% along Blumensaat's line and 34% of the height of the intercondylar notch. The mean tibial socket position was 41.8% (Range: 32%-47%) along the Amis-Jakob Line. Our single surgeon case series utilizing the all-inside, TransLateral ACLR technique highlights good early outcomes with no postoperative complications or graft failure at one year.

Can we predict the graft diameter for autologous hamstring in anterior cruciate ligament reconstruction?

To achieve in the reconstruction of the anterior cruciate ligament a graft with strength, tension and low comorbidity is fundamental. An emerging concept is that a graft diameter of less than 7mm carries a greater risk of re-rupture and instability. Consequently, different methods are being sought to predict intra-surgical size. The objective is to predict the size of the hamstring graft by measuring the area of the semitendinous and gracilis tendon with magnetic resonance imaging (MRI).

METHODOLOGY

We carried out an observational retrospective study of 56 patients. They underwent anterior cruciate ligament reconstruction with 4-GST hamstring graft. The parameters evaluated were anthropometric data, hamstring graft diameter, area of gracilis and semitendinosus tendon in MRI. The measurements were made by three independent evaluators.

RESULTS

The mean diameter of the intrasurgical graft was 8.46mm, in the MRI the area of the gracilis was 8,875mm and the semitendinosus area was 13,068mm. Their mean was 22.12 for the automatic measurement and 21.53 for the manual measurement. The interobserver correlation was regular for the automatic measurement (ICC = 0.595) and low for the manual measurement (ICC = 0.446). The result of the intraobserver correlation was excellent (ICC = 0.917). We did not obtain a statistical correlation between the measurement of areas and the increase of the graft diameter (R = 0.069, P = .63).

CONCLUSION

We determined with our results that the intrasurgical graft size is not predictable with the measurement of the area of the gracilis and semitendinosus tendon on the MRI.

Patellofemoral MRI Alterations Following Single Bundle ACL Reconstruction with Hamstring Autografts Are Associated with Quadriceps Femoris Atrophy

High incidence of patellofemoral pain and patellofemoral joint osteoarthritis was found following anterior cruciate ligament (ACL) reconstruction. The unstability of patellofemoral joint might be an important contribution factor. This study was designed to define the relationship between the unstability of patellofemoral joint and quadriceps femoris atrophy. Twenty patients underwent MRI scan before ACL reconstruction and every two weeks after surgery, until 12 weeks. The merchant's patellar congruence angle, lateral inclination angle, and quadriceps femoris muscle cross-sectional area were measured and the relationship between the changes of angles and the ratio of quadriceps femoris atrophy was studied by multiple regression analysis. Significant quadriceps femoris atrophy was observed after ACL reconstruction during the follow-up period of 12 weeks. The merchant's patellar congruence angle and lateral inclination angle significantly changed after surgery. The alterations of the merchant's patellar congruence angle were significantly correlated with the atrophy ratio of vastus medialis (coefficient=-15.76) and vastus lateralis (coefficient=8.35) during the follow-up period of 12 weeks. The alterations of lateral inclination angle were significantly correlated with the atrophy ratio of vastus medialis (coefficient=20.62), vastus lateralis (coefficient=-11.38) and rectus femoris (coefficient=-0.469) during the follow-up period 12 weeks. To sum up, ACL reconstruction can alleviate the dysfunction of patellofemoral joint to a certain extent. But, the unbalanced atrophy of quadriceps femoris once again destroyed the stability of patellofemoral joint following the operation, which might be one cause of patellofemoral joint pain and early onset of osteoarthritis after ACL reconstruction. So, rehabilitation training that focuses on quadriceps femoris especially the vastus medialis shortly following operation is suggested.

Reliability and methodology of quantitative assessment of harvested and unharvested patellar tendons of ACL injured athletes using ultrasound tissue characterization

Background

Ultrasound tissue characterization (UTC) imaging has been previously used to describe the characteristics of patellar and Achilles tendons. UTC imaging compares and correlates successive ultrasonographic transverse tendon images to calculate the distribution of four color-coded echo-types that represent different tendon tissue types. However, UTC has not been used to describe the characteristics of patellar tendons after anterior cruciate ligament reconstruction (ACLR). The aim of this cross-sectional study was to assess the intra and inter-rater reliability of the UTC in unharvested and harvested patellar tendons of patients undergoing ACLR.

Methods

Intra and inter-rater reliability of both UTC data collection and analysis were assessed. Ten harvested and twenty unharvested patellar tendons from eighteen participants were scanned twice by the same examiner. Eleven harvested and ten unharvested patellar tendons from sixteen participants were scanned and analyzed twice by two different examiners. Twenty harvested and nineteen unharvested patellar tendons from twenty-three participants were analyzed twice by two examiners.

Results

Quantification of the proportion of echo-types I, II, III and IV in the areas of interest: (1) patella apex, (2) proximal tendon, (3) mid tendon, (4) distal tendon, and overall tendon of harvested and unharvested patellar tendons all displayed excellent intra-rater reliability (ICC_2,1: 0.94 to 0.99), excellent inter-rater reliability for harvested and unharvested patellar tendon scanning and analysis (ICC_2,1: 0.89 to 0.98), and excellent inter-rater reliability for analysis (ICC_2,1: 0.95 to 0.99). Intra-rater reliability for the measure of volume was good (ICC_2,1: 0.69 harvested, 0.67 unharvested), whilst mixed results were observed for the measure of mid tendon thickness (ICC_2,1: 0.88 harvested, 0.57 unharvested). Inter-rater reliability for scanning and analysis was good for volume (ICC_2,1: 0.67) and excellent for thickness (ICC_2,1: 0.97), while the inter-rater reliability for analysis was fair to poor for volume (ICC_2,1: 0.59 harvested, 0.30 unharvested), and excellent to poor for mid tendon thickness (ICC_2,1: 0.85 harvested, 0.24 unharvested).

Conclusion

UTC imaging is a reliable tool to characterize the quality of most aspects of unharvested and harvested patellar tendons in subjects undergoing ACLR.

Femoral tunnel position in chronic anterior cruciate ligament rupture reconstruction: randomized controlled trial comparing anatomic, biomechanical and clinical outcomes

PURPOSE

The aim of this study was to compare the outcomes between anteromedial (AM) and transtibial (TT) femoral tunnel positioning techniques for the reconstruction of chronic anterior cruciate ligament (ACL) rupture.

MATERIALS AND METHODS

It is a randomized prospective study of 106 patients who underwent ACL reconstruction because of a chronic ACL rupture (55 AMT, 51 TT). Minimum follow-up was 2 years. Demographic, clinical and radiological data, including MRI grafts' anatomy and biomechanics intraoperative navigation system evaluation, were analyzed. Also, International Knee Documentation Committee score, Tegner Knee score, Lysholm Knee Score, Short-Form Health Survey and 4-point Likert Scale were evaluated.

RESULTS

The AM technique achieves a more anatomic graft than TT technique in both sagittal and coronal plane (6° approximately). Immediate postoperative biomechanical evaluation of the graft showed both techniques significantly improved translational and rotational laxity (p = 0.000). AMT showed superiority only in controlling internal rotation (p = 0.016). Both techniques reported significant improvement in all evaluated score scales, without differences between techniques. Independently of the femoral tunnel positioning technique, patients with cartilage lesion had worse clinical outcomes.

CONCLUSIONS

Our findings suggest that AMT achieves a more anatomical and biomechanically accurate graft allowing better control over internal rotation laxity; however, this does not lead to better clinical outcomes if we compare with TT in the reconstruction of chronic ACL rupture. Patients with chronic ACL rupture and cartilage lesion had worse clinical outcomes, independently the femoral tunnel positioning technique.

Indications and outcomes of simultaneous high tibial osteotomy and ACL reconstruction

PURPOSE

The purpose of this study was to systematically review the existing literature reporting surgical outcomes of simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament reconstruction (ACLR) in anterior cruciate ligament deficient (ACLD) knees.

METHODS

This study was conducted per the methods of the Cochrane Handbook for Systematic Reviews of Intervention, with findings reported per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies and pertinent data was extracted. Studies reporting post-operative outcomes following simultaneous HTO and ACLR in ACLD knees were included.

RESULTS

The search identified 515 studies, of which 18 (n = 516) were included. The mean MINORS scores for non-comparative and comparative studies were 11.6 ± 1.34 and 17.3 ± 1.9, respectively. Simultaneous HTO and ACLR resulted in improved functional subjective patient outcomes across a variety of scales. Simultaneous HTO and ACLR was effective in correcting varus angulation, with the post-operative mechanical angle ranging from 0.3° valgus to 7.7° valgus. The reported complication rate ranged from 0 to 23.5%. Across six studies, a total of 13 (6.5%) patients required revision HTO; while across four studies, 20 (17.5%) patients had failure of the ACL graft, with one receiving revision ACLR.

CONCLUSIONS

Combined HTO and ACLR may be indicated in patients with ACLD knees with varus angulation. This systematic review found that the combined surgery resulted in significant improvement in post-operative functional subjective outcomes. However, it remains unclear if HTO with ACLR is superior to ALCR or HTO alone due to the lack of comparative studies. Overall, HTO with ACLR was found to have low rates of complications, re-ruptures, and need for revision surgery. This review found that patients continued to have progression of OA despite combined HTO with ACLR. Future research is required to better understand the effects of combined HTO and ACLR compared to ACLR or HTO alone and to evaluate the long-term post-operative progression of medial compartment OA following combined HTO and ACLR.

LEVEL OF EVIDENCE

IV.

Efficacy and Tolerability of Progen, a Nutritional Supplement Based on Innovative Plasma Proteins, in ACL Reconstruction: A Multicenter Randomized Controlled Trial

Background:

New biologic strategies are arising to enhance healing and improve the clinical outcome of anterior cruciate ligament (ACL) reconstruction.

Purpose:

To evaluate the efficacy of a new oral nutritional supplement (Progen) that contains hydrolyzed collagen peptides and plasma proteins, a hyaluronic acid–chondroitin sulfate complex, and vitamin C.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

The study included patients who underwent ACL reconstruction with hamstring autografts using the same fixation method. All patients received the same analgesia and physical therapy (PT) protocol and were randomized to receive either the nutritional supplement (supplemented group) or no additional therapy (control group). Patients were followed up at days 7, 30, 60, and 90. Pain was assessed by use of a visual analog scale (VAS) and by analgesic consumption. Clinical outcome was assessed via International Knee Documentation Committee (IKDC) score and the number of PT sessions. Perceived efficacy and tolerability were rated on a 5-point Likert scale. Graft maturation was assessed by a blinded musculoskeletal radiologist using magnetic resonance imaging. The number of adverse events (AEs) was recorded.

Results:

The intention-to-treat analysis included 72 patients, 36 allocated to the supplemented group and 36 to the control group, with no significant differences regarding demographic and preoperative characteristics. Both groups showed significant improvement in pain and function (measured by VAS and IKDC scores) during the 90-day follow-up period (P < .001 for both), without significant differences between groups. The supplemented group had fewer patients that needed analgesics (8.5% vs 50.0%; P < .05) and attended fewer PT sessions (38.0 vs 48.4 sessions; P < .001) at 90 days and had a higher IKDC score at 60 days (62.5 vs 55.5; P = .029) compared with the control group. Patient- and physician-perceived efficacy was considered significantly higher in the supplemented group at 60 and 90 days (P < .05). Perceived tolerability of the overall intervention was better in the supplemented group at 30, 60, and 90 days (P < .05). Graft maturation showed more advanced degrees (grades 3 and 4) in the supplemented group at 90 days (61.8% vs 38.2%; P < .01). No intolerance or AEs associated with the nutritional supplement treatment were reported.

Conclusion:

The combination of the nutritional supplement and PT after ACL reconstruction improved pain, clinical outcome, and graft maturation. Nutritional supplementation showed higher efficacy during the second month of recovery, without causing AEs.

Registration:

NCT03355651 (ClinicalTrials.gov identifier).

Patellofemoral kinematic characteristics in anterior cruciate ligament deficiency and reconstruction

Background

It is very important to dynamically evaluate the functional outcome in the knee after anterior cruciate ligament (ACL) reconstruction under physiological weight bearing. The objective of the current study is that we would like to compare the patellofemoral joint kinematics in three ACL status: ACL intact, ACL deficiency, ACL reconstruction.

Methods

Twenty patients with unilateral ACL deficient knees were recruited as preoperative group. Six months after ACL reconstruction, these ten subjects were included as postoperative subjects. Ten normal subjects with healthy knees as the control group. Each subject was asked to walk up a custom set of stairs and a single-plane fluoroscopic imaging system was used to determine the 6DOF kinematics of the injured knees, ACL reconstructed knees, and intact knees.

Results

ACL deficient knees showed reduced patellar flexion angle and reduced distal patellar translation during knee flexion. ACL reconstructed knees showed abnormal patellofemoral joint kinematics compared to ACL intact and ACL deficient knees, exhibiting increased patellar external rotation, lateral tilt, lateral translation during knee flexion.

Conclusion

These findings imply that some alterations persist after ACL deficiency and ACL reconstruction. These abnormal changes will be the onset of degeneration in patellofemoral joint even if the ACL is reconstructed in a way that restores the clinical anteroposterior stability of the knee. Some biomechanical changes should be made to improve the outcome of intervention especially in surgical treatment like ACL reconstruction.

A Biomechanical Analysis of Tibial Fixation Methods in Hamstring-Graft Anterior Cruciate Ligament Reconstruction

BACKGROUND

There are conflicting results on the biomechanical properties of tibial fixation devices in anterior cruciate ligament reconstruction. The objective of this study is to compare the initial biomechanical properties of tibial fixation in hamstring-graft ACL reconstruction with interference screw, suspension button, and Tape Locking Screw^TM devices. We hypothesized there are no differences in the initial biomechanical properties of these three tibial fixation techniques.

METHODS

Twenty-one fresh-frozen porcine tibiae were equally divided into three groups of seven tibiae to evaluate the fixation of human hamstring tendon grafts with interference screw, suspension button, or Tape Locking Screw fixation. Using a servohydraulic materials testing system, each graft was subjected to 500 cycles of loading followed by a monotonic failure test.

RESULTS

Interference screw fixation demonstrated significantly lower cyclic displacement (1.28 ± 0.73 mm) than the other groups fixated with either a suspension button device (2.54 ± 0.27 mm, p = 0.003) or a Tape Locking Screw (2.32 ± 0.42 mm, p = .009), and a significantly greater cyclic stiffness (212.19 ± 40.30 N/mm) than the Tape Locking Screw (137.64 ± 26.17 N/mm, p = 0.002). The interference screw also demonstrated significantly higher pullout stiffness (166.83 ± 23.22 N/mm) than the suspension button (112.78 ± 24.14 N/mm, P = 0.002) and Tape Locking Screw (109.11 ± 12.91 N/mm, P = 0.0002).

CONCLUSIONS

Tibial fixation with an interference screw demonstrated superior biomechanical properties for cyclic testing compared to the suspension button and Tape Locking Screw. Load to failure did not differ between groups, and there were no significant biomechanical differences between the suspension button and Tape Locking Screw fixation devices.

CLINICAL RELEVANCE

Despite the initial biomechanical differences, all three fixation devices exhibited mean loads to failure and cyclic displacements below clinically relevant thresholds of failure. These data suggest all three fixation methods are viable options for achieving a functional ACL reconstruction.Level of Evidence: V.

Bilateral simultaneous anterior cruciate ligament reconstruction: A case series and review of the literature

Bilateral ACL rupture is a relatively uncommon injury with an incidence of 2-4%. Most bilateral ACL rupture occurs at two different times, but few cases of single-staged bilateral ACL ruptures have also been reported. There have been reports of both single-staged, and two-staged reconstruction of bilateral ACL ruptures in the literature but without a clear consensus. We present a series of five bilateral ACL rupture cases managed by single-staged arthroscopic ACL reconstruction, using quadrupled hamstring grafts. All of them were young males, with an average age of 26.8 years (Range: 19-39 years). Three out of five of these cases (60%) had sustained the injury to both the knees simultaneously while playing sports. All the five patients had generalized joint laxity with significant hyperextension of their knees. All the ten knees (in five patients) were clinically stable, at their last follow-ups. None of the knees had any early or late complications. A single-staged bilateral ACL reconstruction is a safe, reproducible, and cost-effective procedure for patients with a bilateral ACL deficient knee, in experienced hands.

Incidence of Second Anterior Cruciate Ligament Tears and Identification of Associated Risk Factors From 2001 to 2010 Using a Geographic Database

BACKGROUND

The reported rate of second anterior cruciate ligament (ACL) injuries (20%-30%), including graft failure and contralateral ACL tears, after ACL reconstruction (ACLR) or nonoperative therapy indicates that multiple factors may predispose patients to subsequent ACL injuries.

PURPOSE

To determine the incidence of second ACL injuries in a population-based cohort over a 10-year observation period (2001-2010) and to identify factors that contribute to the risk of second injuries.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

International Classification of Diseases, 9th Revision (ICD-9) codes relevant to the diagnosis of an ACL tear and the procedure code for ACLR were utilized to search the Rochester Epidemiology Project, a multidisciplinary county database, between the years of 2001 and 2010. The complete medical records for all cases were reviewed to confirm diagnosis and treatment details. A total of 914 unique patients with 1019 acute, isolated ACL tears were identified. These patients were stratified by primary and secondary tears, sex, age, activity level, side of injury, sex × side of injury, and graft type of reconstruction.

RESULTS

Second ACL tears were recorded in 141 (13.8%) of the 914 patients diagnosed with an ACL tear in Olmsted County, Minnesota, USA, from 2001 to 2010; 50.4% of these occurred in the contralateral knee. A noncontact mechanism was responsible for 76.4% of all ACL injuries. A second ACL injury was influenced by factors of sex × age group, treatment type × age group, and treatment type × activity level. Nonparametric analysis of graft disruption × graft type demonstrated that a higher prevalence of second ACL tears occurred with allografts compared with hamstring autografts (P = .0054) and patellar tendon autografts (P = .0001).

CONCLUSION

The incidence of second ACL tears in this population-based cohort was 13.8%, and half occurred to the ACL of the contralateral knee. Statistically, second ACL injuries differed by sex, occurring in female patients younger than 25 years and male patients aged 26 to 45 years. Allografts continued to be associated with a greater risk of second ACL injuries compared with hamstring and patellar tendon autografts. Nonoperative treatment carried more risk of contralateral tears than ACLR.

Translation, cultural adaptation and validation of simplified Chinese version of the anterior cruciate ligament return to sport after injury (ACL-RSI) scale

PURPOSE

To translate and cross-culturally adapt the anterior cruciate ligament-return to sport after injury (ACL-RSI) into simplified Chinese [ACL-RSI (Cn)].

METHOD

In this diagnostic study, the translation, cross-culturally adaptation, and validation of the ACL-RSI was performed according to international guidelines. A total of 112 patients with ACL reconstruction participated in this study. All were capable of competitive sports before the injury and completed the Knee Injury and Osteoarthritis Outcome (KOOS), the International Knee Documentation Committee (IKDC), the Tampa Scale of Kinesiophobia (TSK), and the Tegner activity score. Forty-eight patients completed the ACL-RSI (Cn) twice within two weeks. The validity was tested using seven premade hypotheses. Internal consistency, reliability, and measurement error was assessed.

RESULT

At meanly 15.6 months postoperative, 81 (72.3%) patients returned to sport, with 57 (50.9%) to competitive sport and 24 (21.4%) to recreational sport. Thirty-one (27.7%) patients didn't return to any sport, with 19 (17.0%) still had planned to return, and 12 (10.7%) gave up sport. The ACL-RSI (Cn) demonstrated excellent validity with all hypotheses confirmed. The outcome of ACL-RSI (Cn) was strongly correlated the KOOS subscale quality of life (r = 0.66, p<0.001), the TSK (r = -0.678, p<0.001), the Tegner score (r = 0.695, p<0.001). There was statistic difference between cases returned (68.6 ± 10.1) and didn't return to sport (41.3 ± 17.7), p<0.001; between cases returned to competitive (71.1 ± 8.9) and recreational sport (62.9 ± 10.5), (P = 0.002); between cases who planned to return (50.7 ± 14.1) and gave up sport (26.5 ± 11.7), (P<0.001). The internal consistency (Cronbach's α = 0.96) and test-retest reliability [intra-class correlation coefficient (ICC) = 0.90] was excellent. The measurement error, floor and ceiling effect was satisfactory. Administration time was 3.2 minutes, and no item was missed.

CONCLUSIONS

The ACL-RSI (Cn) scale was confirmed as a valid, reliable, and feasible tool for evaluating psychological factors influencing return to sport.

Comparison of Poly-L-Lactic Acid and Poly-L-Lactic Acid/Hydroxyapatite Bioabsorbable Screws for Tibial Fixation in ACL Reconstruction: Clinical and Magnetic Resonance Imaging Results

Background

The purpose of this study was to compare the clinical and radiological results of 2 different tibial fixations performed using bioabsorbable screws with added hydroxyapatite (HA) and pure poly-L-lactic acid (PLLA) screws in anterior cruciate ligament (ACL) reconstruction.

Methods

A total of 394 patients who underwent arthroscopic ACL reconstruction between March 2009 and June 2012 were retrospectively reviewed. Of those, 172 patients who took the radiological and clinical evaluations at more than 2 years after surgery were enrolled and divided into 2 groups: PLLA group (n = 86) and PLLA-HA group (n = 86). Both groups were assessed by means of the Lysholm score, International Knee Documentation Committee (IKDC) subjective knee score, and Tegner activity score. Stability was evaluated using the KT-2000 arthrometer. Magnetic resonance imaging was performed to evaluate tibial tunnel widening, screw resorption, osteoingeration, and foreign body reactions.

Results

The PLLA-HA group showed significant reduction in the extent of tibial tunnel widening and foreign body reactions and significant increase in screw resorption compared to the pure PLLA group (p < 0.001 for both). In contrast, postoperative Lysholm score, Tegner activity score, IKDC score, and side-to-side difference on the KT-2000 arthrometer showed no significant differences between groups (p = 0.478, p = 0.906, p = 0.362, and p = 0.078, respectively). The PLLA group showed more significant widening in the proximal tibial tunnel than the PLLA-HA group (p = 0.001). In the correlation analysis, proximal tibial tunnel widening revealed a positive correlation with knee laxity (r = 0.866) and a negative correlation with Lysholm score (r = −0.753) (p < 0.01 for both).

Conclusions

The HA added PLLA screws would be advantageous for tibial graft fixation by reducing tibial tunnel widening, improving osteointegration, and lowering foreign body reactions. Even though no clinically significant differences were noted between the pure PLLA group and PLLA-HA group, widening of the proximal area of the tibial tunnel showed a tendency to increase knee laxity measured using the KT-2000 arthrometer.

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.

Incidence of Second Anterior Cruciate Ligament Tears (1990-2000) and Associated Factors in a Specific Geographic Locale

BACKGROUND

Second anterior cruciate ligament (ACL) tears after reconstruction occur at a reported rate of 20% to 30%. This high frequency indicates that there may be factors that predispose an athlete to graft failure and ACL tears of the contralateral knee.

PURPOSE

To determine the incidence of second ACL injuries in a geographic population-based cohort over a 10-year observation period.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

International Classification of Diseases, 9th Revision (ICD-9) codes relevant to the diagnosis of an ACL tear and the procedure code for ACL reconstruction were searched across the Rochester Epidemiology Project, a multidisciplinary county database, between the years of 1990 and 2000. This cohort of patients was tracked for subsequent ACL injuries through December 31, 2015. The authors identified 1041 patients with acute, isolated ACL tears. These patients were stratified by primary and secondary tears, sex, age, activity level, side of injury, sex by side of injury, and graft type.

RESULTS

Of the 1041 unique patients with a diagnosed ACL tear in Olmsted County, Minnesota, from 1990 to 2000, there were 66 (6.0%) second ACL tears; 66.7% of these tears occurred on the contralateral side. A second ACL injury was influenced by graft type ( P < .0001), election of ACL reconstruction ( P = .0060), and sex by side of injury ( P = .0072). Nonparametric analysis of graft disruption by graft type demonstrated a higher prevalence of second ACL tears with allografts compared with hamstring ( P = .0499) or patellar tendon autografts ( P = .0012).

CONCLUSION

The incidence of second ACL tears in this population-based cohort was 6.0%, with 66.7% of these tears occurring on the contralateral side from the original injury. There was a high population incidence of second ACL injuries in female patients younger than age 20 years. The utilization of patellar tendon autografts significantly reduced the risk of second ACL injuries compared with allografts or hamstring autografts in this cohort.

The fifty highest cited papers in anterior cruciate ligament injury

INTRODUCTION

The anterior cruciate ligament (ACL) is one of the most common injured knee ligaments and at the same time, one of the most frequent injuries seen in the sport orthopaedic practice. Due to the clinical relevance of ACL injuries, numerous papers focussing on this topic including biomechanical-, basic science-, clinical- or animal studies, were published. The purpose of this study was to determine the most frequently cited scientific articles which address this subject, establish a ranking of the 50 highest cited papers and analyse them according to their characteristics.

METHODS

The 50 highest cited articles related to Anterior Cruciate Ligament Injury were searched in Thomson ISI Web of Science® by the use of defined search terms. All types of scientific papers with reference to our topic were ranked according to the absolute number of citations and analyzed for the following characteristics: journal title, year of publication, number of citations, citation density, geographic origin, article type and level of evidence.

RESULTS

The 50 highest cited articles had up to 1624 citations. The top ten papers on this topic were cited 600 times at least. Most papers were published in the American Journal of Sports Medicine. The publication years spanned from 1941 to 2007, with the 1990s and 2000s accounting for half of the articles (n = 25). Seven countries contributed to the top 50 list, with the USA having by far the most contribution (n = 40). The majority of articles could be attributed to the category "Clinical Science & Outcome". Most of them represent a high level of evidence.

DISCUSSION

Scientific articles in the field of ACL injury are highly cited. The majority of these articles are clinical studies that have a high level of evidence. Although most of the articles were published between 1990 and 2007, the highest cited articles in absolute and relative numbers were published in the early 1980s. These articles contain well established scoring- or classification systems.

CONCLUSION

The identification of important papers will help current clinicians and scientists to get an overview on past and current trends in that special field of ACL injury and provides a basis for both further discussion as well as future research.

[Clinical evaluations of anterior cruciate ligament reconstruction with platelet rich plasma]

Objective

To investigate the clinical outcomes of autologous platelet rich plasma (PRP) for anterior cruciate ligament (ACL) reconstruction.

Methods

Between August 2014 and August 2016, 42 patients with ACL ruptures who underwent arthroscopic ACL reconstruction were randomly divided into 2 groups: 21 patients received graft soaked with PRP (trial group) and 21 patients received routine graft in ACL reconstruction (control group). Because 6 patients failed to be followed up, 17 patients of trial group and 19 of control group were enrolled in the study. There was no significant difference in gender, age, body mass index, side, injury reason, disease duration, Kellgren-Lawrence grade, and preoperative visual analogue scale (VAS), Lysholm score, and International Knee Documentation Committee (IKDC) activity scores between 2 groups ( P>0.05). VAS score, Lysholm score, and IKDC activity scores were used to evaluate pain and function at 3 and 12 months postoperatively. Further, second arthroscopy and MRI examination were performed at 12 months postoperatively.

Results

The patients in both groups were followed up 3 to 12 months with an average of 9.83 months. The VAS score, Lysholm score, and IKDC activity scores were significantly improved at 3 and 12 months after operation in 2 groups ( P<0.05), and the scores of trial group were significantly better than those of control group at 3 months ( P<0.05), but no significant difference was found between 2 groups at 12 months ( P>0.05). No complications of effusion, infection, and allergy were observed in 2 groups during follow-up. MRI showed good position of ACL grafts and good signal quality of the graft in the majority of the cases. However, mixed hyperintense and presence of synovial fluid at the femoral bone-tendon graft interface were found in 3 patients of trial group and 4 patients of control group, indicating poor remodeling ligamentation. MRI score was 3.53±1.13 in trial group and was 3.21±0.92 in control group, showing no significant difference ( t=0.936, P=0.356). The second arthroscopy examination showed ligament remodeling score was higher in trial group than control group ( t=3.248, P=0.014), but no significant difference was found in synovial coverage score and the incidence of cartilage repair ( t=2.190, P=0.064; χ2=0.090, P=0.764).

Conclusion

PRP application in allograft ACL reconstruction can improve knee function and relieve pain after operation, which may also accelerate graft remodeling.

Ectopic tissue engineered ligament with silk collagen scaffold for ACL regeneration: A preliminary study

Anterior cruciate ligament (ACL) reconstruction remains a formidable clinical challenge because of the lack of vascularization and adequate cell numbers in the joint cavity. In this study, we developed a novel strategy to mimic the early stage of repair in vivo, which recapitulated extra-articular inflammatory response to facilitate the early ingrowth of blood vessels and cells. A vascularized ectopic tissue engineered ligament (ETEL) with silk collagen scaffold was developed and then transferred to reconstruct the ACL in rabbits without interruption of perfusion. At 2weeks after ACL reconstruction, more well-perfused cells and vessels were found in the regenerated ACL with ETEL, which decreased dramatically at the 4 and 12week time points with collagen deposition and maturation. ACL treated with ETEL exhibited more mature ligament structure and enhanced ligament-bone healing post-reconstructive surgery at 4 and 12weeks, as compared with the control group. In addition, the ETEL group was demonstrated to have higher modulus and stiffness than the control group significantly at 12weeks post-reconstructive surgery. In conclusion, our results demonstrated that the ETEL can provide sufficient vascularity and cellularity during the early stages of healing, and subsequently promote ACL regeneration and ligament-bone healing, suggesting its clinic use as a promising therapeutic modality.

STATEMENT OF SIGNIFICANCE

Early inflammatory cell infiltration, tissue and vessels ingrowth were significantly higher in the extra-articular implanted scaffolds than theses in the joint cavity. By mimicking the early stages of wound repair, which provided extra-articular inflammatory stimulation to facilitate the early ingrowth of blood vessels and cells, a vascularized ectopic tissue engineered ligament (ETEL) with silk collagen scaffold was constructed by subcutaneous implantation for 2weeks. The fully vascularized TE ligament was then transferred to rebuild ACL without blood perfusion interruption, and was demonstrated to exhibit improved ACL regeneration, bone tunnel healing and mechanical properties.

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.

Pain Assessment After Anterior Cruciate Ligament Reconstruction: Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autograft

Background:

Anterior cruciate ligament (ACL) reconstruction is a common outpatient procedure that is accompanied by significant postoperative pain.

Purpose:

To determine differences in acute pain levels between patients undergoing ACL reconstruction with bone–patellar tendon–bone (BTB) versus hamstring tendon (HS) autograft.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 70 patients who underwent primary ACL reconstruction using either BTB or HS autografts consented to participate. The primary outcome of the study was postoperative pain levels (visual analog scale), which were collected immediately after surgery and for 3 days postoperatively. Secondary outcome measures included opioid consumption (intravenous morphine equivalents), hours slept, patient satisfaction, reported breakthrough pain, and calls to the physician.

Results:

Patients treated with BTB had increased pain when compared with those treated with HS in the acute postoperative period (mean ± SD: day 0, 6.0 ± 1.7 vs 5.2 ± 2.0 [P = .066]; day 1, 5.9 ± 1.7 vs 4.9 ±1.7 [P = .024]; day 2, 5.2 ± 1.9 vs 4.1 ± 2.0 [P = .032]; day 3, 4.8 ± 2.1 vs 3.9 ± 2.3 [P = .151]). There were also significant increases in reported breakthrough pain (day 0, 76% vs 43% [P = .009]; day 1, 64% vs 35% [P = .003]) and calls to the physician due to pain (day 1, 19% vs 0% [P = .041]) in the BTB group. There were no significant differences in narcotic requirements or sleep disturbances. Overall, the BTB group reported significantly less satisfaction with pain management on days 0 and 1 (P = .024 and .027, respectively).

Conclusion:

A significant increase in acute postoperative pain was found when performing ACL reconstruction with BTB compared with HS. Patients treated with BTB were more likely to have breakthrough pain, decreased satisfaction with their pain management, and to contact their physician due to pain. These findings suggest a difference in early postoperative pain between the 2 most common graft options for ACL reconstruction. Patients should be informed of the differences in acute postoperative pain when deciding on graft choice with their physician.

Primary Anterior Cruciate Ligament Reconstruction. How Do We Do It?

Anterior cruciate ligament (ACL) tears are frequently seen in current practice mostly affecting the young, active subjects, and usually require ligament reconstruction in order to restore normal knee kinematics. As worldwide interest in anatomic reconstruction grew over the last decade, we have also refined our technique in order to restore the anatomical function as near to the normal as possible. This anatomical restoration concept is believed to prevent the onset of osteoarthritis, which the non-anatomic reconstructions fail to attain. The knowledge gained from the ACL anatomy, function and kinematics has helped in developing the current anatomic methods of reconstruction, which take into account patient anatomy, the rupture pattern, as well as the comorbidities. We present our approach to anatomical single- and double-bundle ACL reconstruction.