Graft choices for anterior cruciate ligament reconstruction

The current status of various preclinical therapeutic approaches for tendon repair

Tendons are fibroblastic structures that link muscle and bone. There are two kinds of tendon injuries, including acute and chronic. Each form of injury or deterioration can result in significant pain and loss of tendon function. The recovery of tendon damage is a complex and time-consuming recovery process. Depending on the anatomical location of the tendon tissue, the clinical outcomes are not the same. The healing of the wound process is divided into three stages that overlap: inflammation, proliferation, and tissue remodeling. Furthermore, the curing tendon has a high re-tear rate. Faced with the challenges, tendon injury management is still a clinical issue that must be resolved as soon as possible. Several newer directions and breakthroughs in tendon recovery have emerged in recent years. This article describes tendon injury and summarizes recent advances in tendon recovery, along with stem cell therapy, gene therapy, Platelet-rich plasma remedy, growth factors, drug treatment, and tissue engineering. Despite the recent fast-growing research in tendon recovery treatment, still, none of them translated to the clinical setting. This review provides a detailed overview of tendon injuries and potential preclinical approaches for treating tendon injuries.

Knee Arthroscopy in the Era of Precision Medicine: A Comprehensive Review of Tailored Approaches and Emerging Technologies

Knee arthroscopy, a minimally invasive procedure, has transformed the treatment of knee pathologies by enabling direct visualization and management with minimal tissue disruption. Recent advances in precision medicine have introduced a new dimension to this field, allowing for highly individualized surgical approaches considering each patient's unique genetic, environmental, and biomechanical characteristics. This review explores the integration of precision medicine into knee arthroscopy, focusing on tailored approaches and emerging technologies. Key innovations such as robotic-assisted surgery, advanced imaging, and patient-specific instrumentation have enhanced surgical accuracy and patient outcomes, reduced recovery times, and minimized postoperative complications. The review also examines the role of biomarkers in guiding personalized treatment strategies, including ligament reconstructions, meniscal repairs, and cartilage restoration, which are now being refined to cater to the specific needs of individual patients. While the benefits of these innovations are clear, there are challenges to widespread adoption, including cost, resource allocation, and the need for further research to validate the efficacy of precision-driven approaches in knee arthroscopy. Moreover, the ethical considerations surrounding personalized medicine, such as patient privacy and genetic data usage, must also be addressed. Despite these barriers, the future of knee arthroscopy in the era of precision medicine holds great promise, with ongoing developments in artificial intelligence, genomics, and biomarker discovery poised to further refine patient-centered care. This comprehensive review provides valuable insights into how precision medicine reshapes knee arthroscopy, offering a glimpse into the future of more targeted and effective orthopedic interventions. By embracing these advancements, surgeons and healthcare providers can ensure optimal outcomes for patients undergoing knee arthroscopy.

A Comparative Analysis of Quadriceps Tendon, Patellar Tendon Bone Allograft, and Cadaver Graft in Anterior Cruciate Ligament (ACL) Repair and Reconstructive Surgery

Anterior cruciate ligament (ACL) injuries are a common occurrence among athletes and active individuals, often necessitating surgical intervention for optimal recovery. The choice of graft material for ACL reconstruction remains a topic of debate, with various options available, including quadriceps tendon (QT), patellar tendon bone allograft (PTBA), and cadaver graft (CG). This paper aims to provide an extensive review and comparison of the efficacy, outcomes, and complications associated with these graft types based on recent research. A systematic literature search following PRISMA guidelines was conducted to identify relevant studies published in the past six years. The findings suggest that while each graft type has its advantages and limitations, there is no definitive superior choice. Factors such as patient age, activity level, comorbidities, and surgeon preference should be considered when selecting the most appropriate graft for ACL repair surgery. QT grafts are associated with lower donor-site morbidity compared to patellar tendon grafts. However, QT grafts may have a higher risk of graft rupture and decreased knee flexion strength. PTBA grafts, compared to QT grafts, have a higher risk of donor-site morbidity but a lower risk of graft rupture and improved knee stability. CG grafts have lower donor-site morbidity compared to PTBA grafts but may have a higher risk of graft rupture and decreased knee flexion strength compared to PTBA grafts. In conclusion, the choice of graft material for ACL reconstruction is a complex decision that requires careful consideration of various factors, including patient age, activity level, comorbidities, and surgeon preference. While each graft type has its advantages and limitations, there is no definitive superior choice. Therefore, it is essential to carefully weigh the risks and benefits of each graft type to ensure optimal outcomes for patients undergoing ACL repair surgery.

Advances in Anterior Cruciate Ligament Injury, Reconstruction and Rehabilitation

Another Special Issue dedicated to the anterior cruciate ligament (ACL) of the knee joint [...].

A comparison of stress, contact pressure, and contact area on menisci in re-injury mechanisms after reconstruction of the anterior cruciate ligament with autograft and synthetic graft: a finite element study

PURPOSE

The anterior cruciate ligament (ACL) is crucial in maintaining knee stability. Some motion mechanisms, which are common in sports, cause excessive load to be passed on the ACL. In non-contact ACL injuries, the ACL cannot sustain the high stress and becomes injured or ruptures in the valgus-external rotation mechanism (VERM) and varus-internal rotation mechanism (VIRM). The mechanical strength of the grafts used to repair the torn ligament varies. The purpose of this study is to look at the alterations in the menisci after anterior cruciate ligament repair with autografts and synthetic grafts in cases of non-contact re-injury mechanisms.

METHODS

In the finite element analysis, VERM and VIRM motions of the injury were simulated with different ACL graft materials. During the simulations of these mechanism motions with polyethylene terephthalate (PET) and patellar tendon (PT), the contact pressures, contact areas, and von mises stress values created in the medial and lateral meniscus were compared.

RESULTS

The peak contact pressures on the menisci during the VERM are higher than the peak contact pressures during the VIRM, except for one variation. The peak contact pressure of the medial meniscus is almost the same for both graft materials and mechanisms. Furthermore, the peak contact pressures in the menisci are higher than in the VERM. For all injury mechanisms, the peak contact stresses on the lateral meniscus are higher than on the medial meniscus.

CONCLUSIONS

The findings suggest that VERM can induce further knee joint injury. It was found that the PET will lessen the pressure on the menisci even more. It is also advantageous since it does not damage the anterior extremities and transmits less pressure to the menisci. In conclusion, using a high-strength ACL is healthier for the menisci. Even though synthetic grafts are not clinically preferred, the study demonstrates that enhancing the material properties of synthetic grafts will increase the chance of their use in the future, based on the current results.

Free tendon grafts for surgical management of chronic tears of the main body of the Achilles tendon: a systematic review

PURPOSE

After four weeks from injury, tears of the Achilles tendon are considered chronic. Their management is challenging, and the use of a graft is suggested when the gap between proximal and distal stumps is greater than 6 cm. The present study systematically reviews the outcome of free tendon grafts in chronic ruptures of the Achilles tendon, evaluating clinical outcomes, complications and return to sport.

METHODS

The present study was conducted according to the PRISMA 2020 guidelines. PubMed, Google Scholar, Embase, and Web of Science databases were accessed in February 2023. All the published clinical studies reporting clinical outcome, return to sport and complications of free tendon grafts used the treatment of chronic rupture of the midportion of the Achilles Tendon were accessed. The mean CMS (Coleman Methodology Score) of 65.7 suggested an overall good quality of the available published articles, attesting to the low risk of bias.

RESULTS

Data from 22 articles (368 patients with a mean age of 47 years) were retrieved. The average time from rupture to surgery was 25.1 week. At last follow-up, the AOFAS (American Orthopaedic Foot and Ankle Surgery) and ATRS (Achilles Tendon Total Rupture Score) scores improved of 33.8 (P = 0.0004), and 45.1 points (P = 0.0001) respectively. Return to activity was reported in 105 patients, and 82 (78.1%) had no activity limitations, while 19 (18.1%) had limited recreational but not daily activity limitations, and 4 (3.8%) reported limitations in daily activities. Return to sport data was reported in six studies, and 45 of 93 (48.4%) patients returned to sport at an average of 22.6 weeks.

CONCLUSION

In chronic tears of the Achilles tendon, with a gap of at least 6 cm, free tendon grafts allow predictable return to sport and acceptable recovery function.

LEVEL OF EVIDENCE

Level IV.

Functional Outcomes Following Arthroscopic Anterior Cruciate Ligament (ACL) Reconstruction Using the Sironix Titanium Button and the Polyetheretherketone (PEEK) Button: A Retrospective Observational Study

Background Anterior cruciate ligament (ACL) injury is most common among athletes compared to the general population. ACL reconstruction is a clinical standard for restoring joint mechanical stability and enabling sports return. The purpose of the study is to evaluate the safety and functional outcomes after arthroscopic ACL reconstruction using the Sironix titanium button and the polyetheretherketone (PEEK) button. Methods A total of 31 subjects who have undergone arthroscopic ACL reconstruction using the Sironix titanium button and PEEK button between August 2022 and January 2023 were included in the study. Demographic data, surgery details, and other baseline characteristics of the subjects were collected from the hospital records. The primary objective of the study was to assess the functional outcome using the International Knee Documentation Committee (IKDC) questionnaire. The secondary objectives were to determine the pre- and post-surgery activity levels using the Tegner Activity Score (TAS) and Lysholm score. Quality of life evaluation was done by using the Quality of Life (QoL) subscale from the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Single Assessment Numerical Evaluation (SANE). Device-related adverse effect information was recorded. Results The mean (SD) of the total IKDC score of 31 subjects at baseline and post-surgery was 51.4 (2.84) and 91.8 (2.59) out of 100, respectively. The mean (SD) of TAS pre-injury and post-surgery was 5.3 (1.47) and 5.4 (1.38) out of 10, respectively. The total mean (SD) value of the total Lysholm Score at baseline and post-surgery was 53.9 (3.72) and 91.4 (3.61) out of 100, respectively. The mean (SD) value of the quality of life subscale of the KOOS score was 91.2 (3.91) out of 100. The total mean (SD) value of the SANE score that had affected joint/region of interest today was 97.4 (1.78), while for the opposite side today, it was 99.5 (0.85) out of 100. There were no adverse device effects reported in this study. Conclusion Based on the score assessment, it was observed that the performance of Sironix knee implant devices, Proloop-Titanium adjustable loop button, T-Button A® Closed PEEK button, and Surestitch® All Inside Meniscal Repair Implant (Healthium Medtech Limited, Bengaluru, Karnataka, India) was effective and safe with no adverse effects. Therefore, Sironix knee implants are considered safe and effective in ACL reconstruction and meniscus repair surgery.

Analysis of the Mechanical Behavior of Porcine Graft Fixation in a Polyurethane Block Using a 3D-printed PLA Interference Screw

Objective  The interest in using 3D printing in the healthcare field has grown over the years, given its advantages and potential in the rapid manufacturing of personalized devices and implants with complex geometries. Thus, the aim of the present study was to compare the mechanical fixation behavior of a 3D-printed interference screw, produced by fused deposition modeling of polylactic acid (PLA) filament, with that of a titanium interference screw. Methods  Eight deep flexor porcine tendons, approximately 8 mm wide and 9 cm long, were used as graft and fixed to a 40 pounds-per-cubic-foot (PCF) polyurethane block at each of its extremities. One group was fixed only with titanium interference screws (group 1) and the other only with 3D-printed PLA screws (BR 20 2021 018283-6 U2) (group 2). The tests were conducted using an EMIC DL 10000 electromechanical universal testing machine in axial traction mode. Results  Group 1 (titanium) obtained peak force of 200 ± 7 N, with mean graft deformation of 8 ± 2 mm, and group 2 (PLA) obtained peak force of 300 ± 30 N, and mean graft deformation of 7 ± 3 mm. Both the titanium and PLA screws provided good graft fixation in the polyurethane block, with no slippage or apparent deformation. In all the samples, the test culminated in graft rupture, with around 20 mm of deformation in relation to the initial length. Conclusion  The 3D-printed PLA screw provided good fixation, similar to that of its titanium counterpart, producing satisfactory and promising results.

Thigh Length as the Most Consistent Anthropometric Parameter in Predicting the Size of Hamstring Tendon Autografts in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Cross-Sectional Study

Background

Individual variability in the length and thickness of hamstring tendon autografts is a serious drawback in using these tendons for anterior cruciate ligament reconstruction (ACLR). In this study, we aimed to determine the correlation between the anthropometric parameters and the size of hamstring tendon autografts.

Methods

In a cross-sectional study, 52 male ACLR candidates were included. The length of semitendinosus and gracilis tendons and the diameter of single, doubled, and quadrupled tendons were measured. A graft sizing block device with an incremental size change of 0.5 mm (range 4.5-12) was used to measure the tendon graft diameter. The evaluated anthropometric parameters included age, gender, height, weight, BMI, thigh length and diameter, calf length, thigh-to-calf ratio, wrist diameter, and ankle diameter. A Pearson's or Spearman's correlation coefficient test was used for evaluating the correlation of anthropometric factors with graft characteristics.

Results

The mean age of the patients was 27.1 ± 6.4 years. The semitendinosus length was significantly correlated with the patient's height (r = 0.373, P = 0.007), thigh length (r = 0.364, P = 0.009), and calf length (r = 0.340, P = 0.015). The gracilis length was significantly correlated with thigh length (r = 0.278, P = 0.049). The mean quadruple diameter was 8.56 ± 1.15 mm (range 6.5-11). The quadruple diameter was significantly correlated with the thigh length (r = 0.283, P = 0.044). No other significant correlation was found between the tendons' size and evaluated anthropometric parameters.

Conclusion

Thigh length was correlated with the semitendinosus length, gracilis length, and quadruple diameter. Therefore, it could be regarded as the most consistent and promising anthropometric factor in the prediction of hamstring autograft size.

"Trends and beliefs in ACL reconstruction surgery: Indian perspectives"

Objectives

The survey aimed to assess trends and beliefs in the management of anterior cruciate ligament reconstruction (ACLR) amongst orthopaedic surgeons in India.

Methods

A survey was created and distributed among the various orthopaedic surgeons from India. The questionnaire included brief details of surgeons and their experience, clinical assessment, management strategies and the rehabilitation protocol.

Results

135 surgeons completed the survey. 35% of them were having experience of more than 12 years. A large number of surgeons were from government academic institutes (35.5%). The most common criteria for deciding about surgery was Clinical evaluation (94.8%). The most common graft choice was hamstring tendon (94%), and suspensory fixation on the femur side and interference screw on the tibial side (80%) is the most common fixation method. Almost two-thirds of surgeons in this survey use bracing to protect ACL graft in the initial phase.

Conclusion

We presented the preferences amongst the group of surgeons on the management of ACL injuries. Hamstring tendon graft remains the most preferred graft for ACL reconstruction. Further, the suspensory loop on the femoral side and interference screw on the tibial side are the preferred fixation method. This group of surgeons is conservative in terms of the timing of surgeries and post-operative bracing. Level of evidence Level V, Expert Opinion.

Rehabilitation and functional outcomes in internally braced and standard ACL reconstructions

Purpose

The purpose of this study was to compare surgical outcomes in patients who underwent ACL reconstruction, with and without internal bracing, at 1-3, 4-7, and 8-12 months of postoperative physical therapy. Previous studies show that ACL reconstruction with internal bracing allows earlier and more aggressive rehabilitation. Therefore, it was hypothesized that patients with internal bracing would display superior surgical recovery compared to ACL reconstruction alone after adjusting for length of physical therapy.1, 2, 3.

Methods

Patients who underwent ACL reconstruction and had a minimum two-year follow-up were included. Demographics including age, gender, use of internal bracing, and pre-operative level of activity were collected. Patient-reported outcomes were assessed using KOOS scores.

Results

46 patients underwent ACL reconstruction between January 2013 and December 2015. The mean age was 31.53 ± 8.37 years. Patients who received ACL reconstruction with internal bracing reported similar improvement in KOOS scores (mean = 42.82 ± 15.44; median = 46.39 [34.52-51.80]) compared to ACL reconstruction alone (mean = 38.18 ± 19.91; median = 40.17 [29.49-53.90]) (p = 0.475). Patients who received ACL reconstruction with internal bracing reported comparable improvement to ACL reconstruction alone at 0-3 months (Internal bracing: mean = 35.39 ± 15.26, median = 40.45 [26.49-47.73]; No internal bracing: mean = 42.51 ± 12.33, median = 39.32 [35.69-52.94], p = 0.4113), 4-7 months (Internal bracing: 41.96 ± 14.49, 45.55 [33.94-52.68]; No internal bracing: 30.64 ± 32.29, 41.65 [26.17-46.12], p = 0.7491) and 8+ months groups (Internal bracing: 63.36 ± 13.06, 63.36 [58.74-67.98]; No internal bracing: 47.05 ± 10.14, 47.05 [43.46-50.63]) (p = 0.6985).

Conclusion

This study demonstrates no statistical difference in functional outcome scores when comparing patients with internally braced ACL reconstruction compared to standard reconstruction. Therefore, the increased structural support provided by use of internal bracing in ACL reconstruction does not afford to quicker improvement in patient-reported recovery.

Management of Patella Fracture Nonunion and Large Bone Defect After Bone-Patellar Tendon-Bone Autograft: A Case Report

CASE

A 32-year-old patient was diagnosed with a vertical patella fracture nonunion after a bone-patellar tendon-bone (BTB) anterior cruciate ligament reconstruction. In addition, a 1 × 2 × 1 cm patellar bone defect was noticed at the graft harvesting site. The patient was treated surgically with open reduction and internal fixation and iliac crest bone autograft which resulted in fracture union.

CONCLUSION

Many intraoperative and postoperative risk factors for iatrogenic patella fracture when harvesting BTB autograft were identified. Surgeons should be aware of technical skills needed to prevent this complication and should treat the fracture appropriately to avoid nonunion and optimize the outcome.

Outcomes Following Anterior Cruciate Ligament Reconstruction with Patellar Tendon vs Hamstring Autografts: A Systematic Review of Randomized Controlled Trials with a Mean Follow-up of 15 Years

BACKGROUND

The two most common surgical treatment modalities for anterior cruciate ligament reconstruction (ACL), patellar tendon (PT) and hamstring tendon (HS) autografts, have been shown to have outcomes that are both similar and favorable; however, many of these are short or intermediate-term. The objective of this systematic review is to evaluate randomized controlled trials (RCTs) with a minimum 10-year follow-up data to compare the long-term outcomes of ACL reconstructions performed using PT and HS autografts.

METHODS

This systematic review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A search of three databases (PubMed, Cochrane and EMBASE) was performed to identify RCTs with a minimum of 10-year follow-up that compared clinical and/or functional outcomes between PT and HS autografts.

RESULTS

Four RCTs with a total of 299 patients were included in the study. The mean follow-up ranged from 10.2 to 17 years (mean, 14.79 years). No significant differences in knee laxity or clinical outcome scores were demonstrated in any of the studies. One study found that PT autografts were significantly more likely to have osteoarthritis identified by radiographic findings. Two studies found that patients with PT autografts reported increase kneeling pain, while none of the four studies reported a difference in anterior knee pain. There were no significant differences in graft failure rates.

CONCLUSION

This review demonstrates no long-term difference in clinical or functional outcomes between PT and HS autografts. However, radiographic and subjective outcomes indicate that patients with PT autografts may experience greater kneeling pain and osteoarthritis. Therefore, orthopaedic surgeons should consider patient-centric factors when discussing graft options with patients.

Association Between Neuromuscular Variables and Graft Harvest in Soft Tissue Quadriceps Tendon Versus Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Autografts

Background:

Quadriceps tendon (QT) autografts are increasingly popular for anterior cruciate ligament reconstruction (ACLR). However, no study has compared QT autografts with bone–patellar tendon–bone (BTB) autografts regarding the electromechanical delay (EMD), the peak torque (PT), and the rate of force development (RFD) in the superficial quadriceps muscles (rectus femoris [RF], vastus medialis [VM], and vastus lateralis [VL]).

Hypotheses:

We hypothesized (1) there would be a significantly lower PT, lower RFD, and longer quadriceps EMD of the operative limb for the QT versus the BTB autograft; (2) the PT, the RFD, and the quadriceps EMD of the operative limb would be significantly depressed compared with those of the nonoperative limb, regardless of the surgical technique; and (3) there would be greater increases in the RF EMD than in the VM or the VL EMD.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 34 patients (age, 18-40 years), who had undergone ACLR (QT, n = 17; BTB, n = 17) at least 1 year before testing and performed 3 perceived maximal effort isometric tests, which were time synchronized with surface electromyography (EMG) on their operative and nonoperative limbs, were included in this study. EMD, PT, and RFD data were analyzed using a 2 (limb) × 2 (graft) × 3 (repetition) mixed repeated-measures analysis of variance.

Results:

The EMD, the PT, and the RFD were not significantly affected by graft choice. For the VL, a significant repetition × graft × limb interaction was detected for the VL EMD (P = .027; ηp = 0.075), with repetition 3 having longer EMD than repetition 2 (mean difference [MD], 16 milliseconds; P = .039). For the RF EMD, there was a significant repetition × limb interaction (P = .027; ηp = 0.074), with repetition 3 being significantly longer on the operative versus the nonoperative limb (MD, 24 milliseconds; P = .004). Further, the operative limb EMD was significantly longer for repetition 3 versus repetition 2 (MD, 17 milliseconds; P = .042). For the PT, there was a significant effect for repetition (P = .003; ηp = 0.114), with repetition 1 being significantly higher than both repetitions 2 (MD, 8.52 N·m; P = .001) and 3 (MD, 7.79 N·m; P = .031). For the RFD, significant limb (P = .034; ηp = 0.092) and repetition (P = .010; ηp = 0.093) effects were seen, with the nonoperative limb being significantly faster than the operative limb (MD, 23.7 N·m/s; P = .034) and repetition 1 being significantly slower than repetitions 2 (MD, -20.46 N·m/s; P = .039) or 3 (MD, −29.85 N·m/s; P = .002).

Conclusion:

The EMD, the PT, and the RFD were not significantly affected by graft type when comparing QT and BTB autografts for ACLR; however, all neuromuscular variables were affected regardless of the QT or the BTB harvest.

Biofabrication Strategies for Musculoskeletal Disorders: Evolution towards Clinical Applications

Biofabrication has emerged as an attractive strategy to personalise medical care and provide new treatments for common organ damage or diseases. While it has made impactful headway in e.g., skin grafting, drug testing and cancer research purposes, its application to treat musculoskeletal tissue disorders in a clinical setting remains scarce. Albeit with several in vitro breakthroughs over the past decade, standard musculoskeletal treatments are still limited to palliative care or surgical interventions with limited long-term effects and biological functionality. To better understand this lack of translation, it is important to study connections between basic science challenges and developments with translational hurdles and evolving frameworks for this fully disruptive technology that is biofabrication. This review paper thus looks closely at the processing stage of biofabrication, specifically at the bioinks suitable for musculoskeletal tissue fabrication and their trends of usage. This includes underlying composite bioink strategies to address the shortfalls of sole biomaterials. We also review recent advances made to overcome long-standing challenges in the field of biofabrication, namely bioprinting of low-viscosity bioinks, controlled delivery of growth factors, and the fabrication of spatially graded biological and structural scaffolds to help biofabricate more clinically relevant constructs. We further explore the clinical application of biofabricated musculoskeletal structures, regulatory pathways, and challenges for clinical translation, while identifying the opportunities that currently lie closest to clinical translation. In this article, we consider the next era of biofabrication and the overarching challenges that need to be addressed to reach clinical relevance.

Crossed doubled patellar tendon: A rare anatomical variant with potential clinical significance

The patellar tendon is an integral part of the knee extensor mechanism and has been historically described as a single tendon. A doubled patellar tendon is an exceedingly rare finding. We present a case of a crossed doubled patellar tendon in a 70-year-old male with a history of right knee pain, which to our knowledge has only been reported once before in the literature. The presence of a doubled patellar tendon has a potential influence on surgical planning and in the etiology of anterior knee pain.

Basic Research on Tendon Repair: Strategies, Evaluation, and Development

Tendon is a fibro-elastic structure that links muscle and bone. Tendon injury can be divided into two types, chronic and acute. Each type of injury or degeneration can cause substantial pain and the loss of tendon function. The natural healing process of tendon injury is complex. According to the anatomical position of tendon tissue, the clinical results are different. The wound healing process includes three overlapping stages: wound healing, proliferation and tissue remodeling. Besides, the healing tendon also faces a high re-tear rate. Faced with the above difficulties, management of tendon injuries remains a clinical problem and needs to be solved urgently. In recent years, there are many new directions and advances in tendon healing. This review introduces tendon injury and sums up the development of tendon healing in recent years, including gene therapy, stem cell therapy, Platelet-rich plasma (PRP) therapy, growth factor and drug therapy and tissue engineering. Although most of these therapies have not yet developed to mature clinical application stage, with the repeated verification by researchers and continuous optimization of curative effect, that day will not be too far away.

Premature hamstring graft amputation during harvesting in ACL reconstruction

Introduction

There are some possible complications during or after hamstring graft harvesting such as premature graft amputation, medial collateral ligament injury and infrapatellar branch of the saphenous nerve injury. Premature graft amputation can occur by inadequate removal of the accessory branches of the hamstring tendons, poor surgical technique and/or too sharp tendon stripper. In this study, we report a case of premature hamstring graft amputation due to degeneration caused by osteochondroma at the posteromedial aspect of the proximal tibia.

Case presentation

We reported the case of a 28-year-old Thai male who had an ACL injury was scheduled for ACL reconstruction. In this case, we had planned to use a hamstring graft for double-bundle ACL reconstruction. During the gracilis tendon harvesting, the graft was prematurely amputated by a tendon stripper at the level of the osteochondroma. The premature graft amputation was sent for pathology, which showed degenerated tissue.

Conclusion

In cases of osteochondroma at the posteromedial aspect of the proximal tibia, it is a chance of premature hamstring graft amputation. We suggest removing the osteochondroma before harvesting the tendon grafts to avoid the risk of premature graft transection.

•

The incidence of premature graft amputation is rare.

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In this patient, premature graft amputation caused by osteochondroma at the posteromedial aspect of the proximal tibia.

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In cases of osteochondroma at the medial proximal tibia, we suggest removing the osteochondroma before harvesting the tendon grafts.

Physicochemical Properties and Biocompatibility of Electrospun Polycaprolactone/Gelatin Nanofibers

Tissue-engineered substitutes have shown great promise as a potential replacement for current tissue grafts to treat tendon/ligament injury. Herein, we have fabricated aligned polycaprolactone (PCL) and gelatin (GT) nanofibers and further evaluated their physicochemical properties and biocompatibility. PCL and GT were mixed at a ratio of 100:0, 70:30, 50:50, 30:70, 0:100, and electrospun to generate aligned nanofibers. The PCL/GT nanofibers were assessed to determine the diameter, alignment, water contact angle, degradation, and surface chemical analysis. The effects on cells were evaluated through Wharton's jelly-derived mesenchymal stem cell (WJ-MSC) viability, alignment and tenogenic differentiation. The PCL/GT nanofibers were aligned and had a mean fiber diameter within 200-800 nm. Increasing the GT concentration reduced the water contact angle of the nanofibers. GT nanofibers alone degraded fastest, observed only within 2 days. Chemical composition analysis confirmed the presence of PCL and GT in the nanofibers. The WJ-MSCs were aligned and remained viable after 7 days with the PCL/GT nanofibers. Additionally, the PCL/GT nanofibers supported tenogenic differentiation of WJ-MSCs. The fabricated PCL/GT nanofibers have a diameter that closely resembles the native tissue's collagen fibrils and have good biocompatibility. Thus, our study demonstrated the suitability of PCL/GT nanofibers for tendon/ligament tissue engineering applications.

Original study: early patient-reported functional outcome of all-inside ACL reconstruction as compared to anteromedial portal technique

BACKGROUND

Anteromedial portal technique (AMP) using hamstring autograft is a popular technique of arthroscopic ACL reconstruction allowing anatomical placement of femoral. In this technique, a cortical suspensory fixation of graft is used on the femoral side and interference screw fixation on the tibial side using a complete bone tunnel. All-inside translateral technique is a recently introduced technique which uses a closed loop of quadrupled semitendinosus graft with an adjustable cortical suspensory fixation on both sides allowing optimum tensioning of graft and near-complete filling of retrosockets created by the flip cutter on both femoral and tibial sides. With its proposed but unproven benefits, our study was planned to compare the two techniques.

METHODS

A total of 80 young active males requiring ACL reconstruction surgery were equally randomized to AMP and All-inside technique. The primary objective of the study was to compare the ability to return to pre-injury level of activity using Tegner activity scale and patient-reported outcome using new Knee Society Score (KSS) at two years of follow-up.

RESULTS

The mean improvement in Tegner score was significantly better (p = 0.0005) in all-inside group (2.34 ± 0.97) as compared to AMP group (1.5 ± 1.30). Among components of new KSS, patient satisfaction was better in all-inside group.

CONCLUSION

All-inside ACL reconstruction provides a better chance of return to pre-injury level of activity with accompanied patient satisfaction as compared to AMP technique at two years of follow-up.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Radiographic assessment of bone tunnels after anterior cruciate ligament reconstruction: A comparison of hamstring tendon and bone-patellar tendon-bone autografting technique

Objectives

This study aims to compare the postoperative change of femoral and tibial tunnel widths after hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) autografting in primary anterior cruciate ligament (ACL) reconstruction surgery with the anteromedial portal technique.

Patients and methods

This case-control and retrospective study included 39 patients (36 males, 3 females; mean age 30.1±7.9; range, 17 to 44 years) who underwent primary ACL reconstruction surgery with either BPTB autografting method (BPTB group, n=18) or HT autografting method (HT group, n=21) between March 2014 and December 2016. Femoral fixation was achieved with bioabsorbable screw in BPTB group and endobutton in HT group. Tibial fixation was achieved with bioabsorbable interference screw in both groups. Femoral and tibial tunnel widths of groups were compared on digital radiographs.

Results

When we compared the baseline values with the second-year results, the mean of femoral tunnel widths were significantly lower on radiographs at the second-year evaluation in both groups (p<0.001 for all). However, the means of tibial tunnel widths were significantly lower only in the BPTB group (p<0.001 for BPTB group and p=0.616 for HT group). Change levels of anteroposterior and lateral widths were more prominent in BPTB group than HT group (p<0.001 for all).

Conclusion

Changes in tunnel widths show us superior ossification in BPTB grafting. This can be explained by superior bone-to-bone healing. As a result of radiological evaluation, we think that BPTB grafting can be more strong and durable.

Tendon-like tether formation for tongue-base advancement in an ovine model using a novel implant device intended for the surgical management of obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a serious debilitating condition with significant morbidity and mortality affecting almost one billion adults globally. The current gold standard in the non-surgical management of airway collapse is continuous positive airway pressure (CPAP). However, non-compliance leads to a high abandon rate (27-46%). While there are multiple sites of airway obstruction during sleep, the tongue base is recognized as the key player in the pathogenesis of OSA. Poor outcomes of current tongue suspension devices are due to fracture, slippage or migration of devices. Three tongue tethering device groups, namely a polydioxanone/polyurethane combination (PDO + PU) treatment group, a PDO analytical control group, and a polypropylene (PP) descriptive control group, were implanted into 22 sheep (75-85 kg) in a two-phased study. After implant times of 8, 16, and 32 weeks, sheep were serially euthanized to allow for explantation of their tongues and chins. The PDO + PU devices remodeled during the 32-week implant period into a hybrid biological tendon-like tether through the process of gradual degradation of the PDO and collagen deposition as shown by electrophoresis, histology and mechanical testing. The control PDO device degraded completely after 32 weeks and the PP devices remained intact. The hybrid biological tendon-like tether exhibited a break-strength of 60 N, thus exceeding the maximum force to overcome upper airway collapse.

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.

[Arthroscopic reconstruction of anterior cruciate ligament with autologous ipsilateral peroneus longus tendon]

OBJECTIVE

To investigate the effectiveness of anterior cruciate ligament (ACL) reconstruction with the autologous ipsilateral peroneus longus tendon (PLT) under arthroscopy.

METHODS

A retrospective study was conducted on 35 patients with ACL rupture who underwent ACL reconstruction with autologous ipsilateral PLT under arthroscopy between October 2017 and October 2018. There were 19 males and 16 females with an average age of 43.4 years (range, 18-60 years), with 20 cases of left knee and 15 cases of right knee. The causes of injury included traffic accident in 14 cases, falling injury in 13 cases, and sports injury in 8 cases. The time from injury to operation ranged from 3 to 9 days (mean, 4.7 days). The patients suffered from swelling, pain, and limited mobility of knee joint before operation. The anterior drawer test, Lachman test, and pivot-shift test were positive before operation, whereas MRI was taken to confirm the ACL rupture. After operation, the patients were followed up every 3 months until the knee joint's function returned to normal. MRI and X-ray films were used to observe the tendon-bone healing as well as the position of Endobutton suspension plate and hollow nail. The anterior drawer test, Lachman test, and pivot-shift test were conducted to observe the improvement of knee joint mobility. The functional improvements were evaluated by the International Knee Documents Committee (IKDC) score, Lysholm score, knee injury and osteoarthritis (KOOS) score.

RESULTS

All the 35 patients were followed up 12-18 months, with an average of 14.2 months. The incisions healed by first intention, and no complications such as infection, joint stiffness, and rerupture occurred. Postoperative anterior drawer test, Lachman test, and pivot-shift test turned to be negative of all patients. MRI showed that the ACL was continuous, and the tendon-bone in the distal femur tunnel and proximal tibia tunnel recovered well after operation. X-ray films showed that the positions of Endobutton suspension plate and hollow nail were stable. The IKDC, Lysholm, and KOOS scores at 3, 6, and 12 months after operation were significantly improved when compared with those before operation, and the scores were further improved with time after operation ( P<0.05).

CONCLUSION

For patients with ACL rupture, ACL reconstruction with the autologous ipsilateral PLT under arthroscopy has satisfactory effectiveness of quick recovery, good function, and great stability.

The Effectiveness of Autograft Used in Anterior Cruciate Ligament Reconstruction of the Knee: Surgical Records for the New Generations of Orthopedic Surgeons and Synthetic Graft Revisit

Objective

In this article, we aim to revisit the synthetic graft and review the advantages and disadvantages between different types of grafts for patients who underwent anterior cruciate ligament (ACL) reconstruction in a tertiary medical institute for the new generations of surgeons.

Patients and Methods

Retrospectively, we identified 115 patients who underwent arthroscopic ACL reconstruction between 2006 and 2009. We were able to retrieve 74 patients from them. The 74 patients were divided into 32 patients who underwent primary arthroscopic ACL reconstruction with hamstring and patellar tendon autograft and 42 cases with an active biosynthetic composite (ABC) ligament. The mean the follow-up period for both groups was 7 years. The following information was obtained: standard demographic information (age, sex), clinical presentation, presence of trauma, associated injuries, types of grafts (autograft versus synthetic graft) and postoperative complications. Moreover, functional and clinical outcomes in addition to the satisfaction of patients using the international knee documentation committee (IKDC) score and knee injury and osteoarthritis outcome score (KOOS) were measured.

Results

We found that the natural (autograft) was better in terms of clinical and functional outcome than the synthetic one (the scores of KOOS and IKDC were better in natural grafts). Furthermore, the immediate postoperative results for the pivot and Lachman tests were better in natural grafts. On the other hand, the rate of re-rupture was similar for both groups. However, the long-term inflammatory changes and stiffness that is attributed to the immunological reactions were more in the synthetic grafts.

Conclusion

This study revisited the synthetic graft and provided evidence that the natural grafts are more beneficial with less complications, as they had better immediate and long-term postoperative clinical and functional outcomes. We recommend the utilization of autograft as first choice and the synthetic not to be used given the current criteria.

Factors associated with revision following anterior cruciate ligament reconstruction: A systematic review of registry data

BACKGROUND

To identify the patient and surgical factors associated with revision anterior cruciate ligament (ACL) reconstruction as reported by all national and community ACL registries.

METHODS

A systematic review was performed on the MEDLINE, Embase and Cochrane Library databases. Eligibility criteria included English studies published by national or community ACL registries reporting on primary ACL reconstruction and risk factors associated with revision ACL reconstruction.

RESULTS

Thirty-three studies from the Swedish, Norwegian, Danish and Kaiser Permanente registries were included for review. Fourteen studies from all four registries reported younger age as a risk factor for revision ACL reconstruction. In addition, the Swedish registry reported concomitant medial collateral ligament (MCL) injury, undergoing earlier surgery, lower Knee Injury and Osteoarthritis Outcome Score (KOOS), smaller graft diameter and an anteromedial portal drilling technique as risk factors for revision. The risk factors reported by the Norwegian registry included lower body mass index (BMI), lower KOOS, hamstring tendon grafts and suspensory fixation. The Danish registry reported hamstring tendon grafts, anteromedial portal drilling and suspensory fixation as risk factors. The Kaiser Permanente registry reported male sex, lower BMI, ethnicity, hamstring tendon grafts, allografts, smaller graft diameter and an anteromedial portal technique as risk factors for revision.

CONCLUSION

Multiple patient and surgical factors were associated with increased risk of revision ACL reconstruction in registries. Younger age and the use of hamstring tendon grafts were consistently reported as risk factors for failure.

Predicting adequacy of free quadriceps tendon autograft, for primary and revision ACL reconstruction, from patients' physical parameters

PURPOSE

Free quadriceps tendon autograft (QTA) has gained popularity for both primary and revision ACL reconstruction. The aim of this study is to measure the dimensions of quadriceps tendon and determine its correlation with patient's height, weight and BMI. This is to provide a guide for patients and surgeons in predicting the suitability of QTA for ACL reconstructions.

METHODS

A cross-sectional study in which the length and thickness of the quadriceps tendon was measured in 51 Caucasian patients who underwent primary total knee arthroplasty. Exclusion criteria include non-Caucasians and previous tendon pathology. Patients were selected from routine elective total knee arthroplasty list. Tendon length is taken from musculotendinous junction to its insertion. Thickness was measured at midpoint and at distal insertion. Patients' height, weight and BMI were recorded. The correlation between patient physical parameters and tendon dimensions were determined.

RESULTS

Subjects' median age was 65 years (range 44-87), with 34 females and 17 males. Median length of the tendon was 9 mm (range 70-110), and median insertional thickness was 9 mm (7-10 mm). Median thickness at midpoint was 7 mm (range 4-10 mm). There was moderately positive correlation between subjects' height and tendon length (correlation coefficient 0.50), and also between weight and tendon length (correlation coefficient 0.47). There was no significant correlation between subjects' BMI and the tendon length. There was also no significant correlation between tendon thickness and subject's physical parameters.

CONCLUSION

This study has shown that most patients could provide adequate QTA for ACL reconstruction. It also points to the fact that no investigation is required to predict the adequacy of QTA. Though further studies with larger sample size are required to confirm this, clinician can rely on analysing patients' physical parameter in predicting the adequacy of QTA for ACL reconstruction.

LEVEL OF EVIDENCE

II.

Current Progress in Tendon and Ligament Tissue Engineering

Background

Tendon and ligament injuries accounted for 30% of all musculoskeletal consultations with 4 million new incidences worldwide each year and thus imposed a significant burden to the society and the economy. Damaged tendon and ligament can severely affect the normal body movement and might lead to many complications if not treated promptly and adequately. Current conventional treatment through surgical repair and tissue graft are ineffective with a high rate of recurrence.

Methods

In this review, we first discussed the anatomy, physiology and pathophysiology of tendon and ligament injuries and its current treatment. Secondly, we explored the current role of tendon and ligament tissue engineering, describing its recent advances. After that, we also described stem cell and cell secreted product approaches in tendon and ligament injuries. Lastly, we examined the role of the bioreactor and mechanical loading in in vitro maturation of engineered tendon and ligament.

Results

Tissue engineering offers various alternative ways of treatment from biological tissue constructs to stem cell therapy and cell secreted products. Bioreactor with mechanical stimulation is instrumental in preparing mature engineered tendon and ligament substitutes in vitro.

Conclusions

Tissue engineering showed great promise in replacing the damaged tendon and ligament. However, more study is needed to develop ideal engineered tendon and ligament.

Hamstrings and Quadriceps Muscles Function in Subjects with Prior ACL Reconstruction Surgery

BACKGROUND

As the knee joint is a common site for injury among younger people, the purpose of this study was to measure the skeletal muscle endurance and strength on people with prior anterior cruciate ligament (ACL) knee reconstruction surgery.

METHOD

Young healthy female subjects who reported having knee reconstruction surgery more than one-year prior were tested. The skeletal muscle endurance index (EI) of the hamstrings and quadriceps muscles was determined as the decline in the specific muscle acceleration in response to 2 Hz, 4 Hz, and 6 Hz electrical stimulation. Maximal isometric muscle strength (MVC) was measured in the hamstrings and quadriceps muscles.

RESULTS

The hamstrings muscles in the injured leg had less endurance than the non-injured leg at 6 Hz stimulation (55.5 ± 13.2% versus 78.0 ± 13.3%, p < 0.01). Muscle endurance was not reduced in the quadriceps muscles in the injured leg compared to the non-injured leg at 6 Hz stimulation (78.0 ± 13.3% versus 80.3 ± 10.0%, p = 0.45). There were no differences in MVC between the injured and non-injured legs for either the hamstrings (p = 0.20) or quadriceps muscles (p = 0.67).

CONCLUSIONS

Muscle endurance was reduced in the hamstrings muscles at least one-year post injury, while hamstrings strength was recovered. Reduced hamstrings muscle endurance could be a result of lack of endurance training during rehabilitation. This may contribute to re-injury in the muscle, even in people who have recovered muscle strength.

Comparison of patellar versus hamstring tendon autografts in arthroscopic anterior cruciate ligament reconstruction: A 6-month follow-up of a randomized clinical trial

Background:

The purpose of this study was to compare the outcomes of anterior cruciate ligament (ACL) reconstruction using the patellar versus hamstring tendon (HT) autograft.

Materials and Methods:

In this randomized clinical trial, fifty patients undergoing arthroscopic ACL reconstruction were randomized into two equal groups: Those treated with either autogenous patellar tendon grafts (PT group) or HT group grafts. All patients were reviewed immediately after surgery, at 6 and 12 weeks after surgery, and then at 6 months using the International Knee Documentation Committee evaluation form. Infection, severity of pain (visual analog scale), duration of rehabilitation, and clinical and magnetic resonance imaging (MRI) findings were assessed at the 6-month follow-up. Positive pivot shift and Lachman test were considered clinical signs and symptoms of treatment failure. In addition, the absence of the ACL or transverse ACL rather than the posterior oblique ligament is an MRI finding that indicates treatment failure.

Results:

Comparing changes in pain and range of motion (ROM) in patients first and 6 months after therapy show that pain had been relief significantly (P < 0.001) and ROM dramatically changes (P < 0.001). The average rehabilitation period in the PT group was 13.2 ± 2.08 weeks whereas in the HT group, it was 9.28 ± 2.26 weeks. A significant difference was seen between the two groups in terms of the rehabilitation period (P < 0.001). No significant difference was found in the normal ROM between the groups (P = 0.32). When the pain severity was considered, a significant difference was found between the PT group and the HT group (P < 0.001). The HT group patients had less knee pain than did the PT group patients. No significant difference in infection rates was seen between two groups (P = 0.66).

Conclusion:

Considering the better outcomes of HT reconstructions for the two parameters of pain severity and rehabilitation period, we consider HTs to be the ideal graft choice for ACL reconstructions.