Resolvin E1 and Cytokines Environment in Skeletally Immature and Adult ACL Tears

Biologic Impact of Anterior Cruciate Ligament Injury and Reconstruction

Surgical intervention after anterior cruciate ligament (ACL) tears is typically required because of the limited healing capacity of the ACL. However, mechanical factors and the inflammatory response triggered by the injury and surgery can impact patient outcomes. This review explores key aspects of ACL injury and reconstruction biology, including the inflammatory response, limited spontaneous healing, secondary inflammation after reconstruction, and graft healing processes. Understanding these biologic mechanisms is crucial for developing new treatment strategies and enhancing patient well-being. By shedding light on these aspects, clinicians and researchers can work toward improving quality of life for individuals affected by ACL tears.

Epidemiology and distribution of cruciate ligament injuries in children and adolescents, with an analysis of risk factors for concomitant meniscal tear

Introduction

To investigate the epidemiological features and prevalence of cruciate ligament injuries (CLI) in children and adolescents, and to examine the potential risk factors associated with concomitant meniscal tear (MT) among this population.

Methods

The demographic data and injury details of children and adolescents with CLI from Southeast China were analyzed to describe their distribution characteristics, alongside an analysis of the prevalence of MTs, the most frequent complication. In addition, binary logistic analysis was employed to ascertain the risk factors linked to MT in individuals suffering from CLI.

Results

A total of 203 patients with CLI (n = 206) met the inclusion criteria, with a male-to-female ratio of 2.3:1. Notably, a higher proportion of females were aged ≤16 years old compared to males, who predominated in patients aged >16 years (P = 0.001). Among children and adolescents, anterior cruciate ligament (ACL) injuries were the primary type of CLI, accounting for 88.18% (179/203) of all cases. The majority of cases (132/203, 65.02%) were sustained during sports activities, and sprains were the predominant mechanism of injury (176/203, 86.7%). Additionally, the most common associated injury was an MT (157/203, 77.34%). The posterior horn is the most frequently affected site for both medial MT (62.93% out of 73 cases) and lateral MT (70.19% out of 73 cases). Moreover, vertical tears constituted the majority of medial MTs (59.48% out of 116 cases). Furthermore, patients with a higher BMI faced an increased risk of associated MT in comparison to non-overweight patients (88% vs. 73.86%; P = 0.038). Each increase in BMI unit was linked with a 14% higher probability of associated MT occurrence in children and adolescents with CLI (OR = 1.140; P = 0.036).

Discussion

ACL injuries are a common form of knee ligament injury among children and adolescents, especially those over the age of 16, and are often the result of a sprain. Meniscal posterior horn injury is the most commonly associated injury of youth with CLI. Additionally, overweight or obese people with CLI are at a greater risk of developing MT.

From Inflammation to Resolution: Specialized Pro-resolving Mediators in Posttraumatic Osteoarthritis

PURPOSE OF REVIEW

To provide a comprehensive overview of the inflammatory response following anterior cruciate ligament (ACL) injury and to highlight the relationship between specialized pro-resolving mediators (SPMs) and inflammatory joint conditions, emphasizing the therapeutic potential of modulating the post-injury resolution of inflammation to prevent posttraumatic osteoarthritis (PTOA).

RECENT FINDINGS

The inflammatory response triggered after joint injuries such as ACL tear plays a critical role in posttraumatic osteoarthritis development. Inflammation is a necessary process for tissue healing, but unresolved or overactivated inflammation can lead to chronic diseases. SPMs, a family of lipid molecules derived from essential fatty acids, have emerged as active players in the resolution of inflammation and tissue repair. While their role in other inflammatory conditions has been studied, their relationship with PTOA remains underexplored. Proinflammatory mediators contribute to cartilage degradation and PTOA pathogenesis, while anti-inflammatory and pro-resolving mediators may have chondroprotective effects. Therapies aimed at suppressing inflammation in PTOA have limitations, as inflammation is crucial for tissue healing. SPMs offer a pro-resolving response without causing immunosuppression, making them a promising therapeutic option. The known onset date of PTOA makes it amenable to early interventions, and activating pro-resolving pathways may provide new possibilities for preventing PTOA progression. Harnessing the pro-resolving potential of SPMs may hold promise for preventing PTOA and restoring tissue homeostasis and function after joint injuries.

Management of anterior cruciate ligament tears in Tanner stage 1 and 2 children: a narrative review and treatment algorithm guided by ACL tear location

The incidence of anterior cruciate ligament (ACL) tears in skeletally immature patients has acutely increased over the last 20 years, yet there is no consensus on a single "best treatment." Selection of an optimal treatment is critical and based on individual circumstances; consequently, we propose a treatment-selection algorithm based on skeletal development, ACL tear location, type, and quality, as well as parental perspective in order to facilitate the decision-making process. We combined our surgical group's extensive case histories of ACL tear management in Tanner Stage 1 and 2 patients with those in the literature to form a consolidated data base. For each case the diagnostic phase, communication with patient and parents, treatment choice(s), selected surgical techniques and rehabilitation schedule were critically analyzed and compared for patient outcomes. MRI-imaging and intraoperative tissue quality assessment were preeminent in importance for selection of the optimal treatment strategy. Considerations for selecting an optimal treatment included: associated lesions, the child/patient and parent(s)' well-informed and counseled consent, biological potential, and the potential for successful ACL preservative surgery. Complete ACL tears were evaluated according to tear-location. In type I and II ACL tears with remaining good tissue quality, we propose primary ACL repair. In type III and IV ACL tears we propose physeal-sparing reconstruction with an iliotibial band graft. Finally, in the case of a type V ACL tear, we propose that the best treatment be based on the Meyers-McKeever classification. We present a facile decision-making algorithm for ACL management in pediatric patients based on specific elements of tissue damage and status.

Prokineticin 2 and Cytokine Content in the Synovial Fluid of Knee Osteoarthritis and Traumatic Meniscal Tear Patients: Preliminary Results

Knee osteoarthritis (OA) is a chronic degenerative inflammatory-based condition caused by a cascade of different intra-articular molecules including several cytokines. Among the cytokines, prokineticins (PKs) have recently been identified as important mediators of inflammation and pain. This observational study examined the potential involvement of PK2 in degenerative or traumatic knee disease. Fifteen patients presenting knee osteoarthritis (OA group) and 15 patients presenting a traumatic meniscal tear (TM group) were studied. Synovial fluid samples from affected knees were assessed for PK2, IL-10, and TNF-α using the ELISA method. At a long-term follow-up (minimum 5 years, mean = 6.1 years), patients in the TM group underwent clinical re-evaluation with PROMs (Tegner Activity Scale, IKDC, Lysholm, SKV); in addition, X-ray visualization was used to assess the presence of secondary OA. PK2 was detected in synovial fluids of both TM and OA patients and the levels were comparable between the two groups, while IL-10 levels were significantly greater in the OA group than those in TM patients. PK2 levels correlated with those of IL-10. PK2 levels were greater in blood effusions compared to clear samples, did not differ significantly between sexes, nor were they related to differences in weight, height, or injury (meniscal laterality, time since dosing). No correlation was found between PROMs and radiological classifications in patients in the TM group at final follow-up. These data are the first observations of PK2 in synovial fluid following traumatic meniscus injury. These findings suggest possible further prognostic indices and therapeutic targets to limit the development of secondary OA.

Surgical techniques in the management of pediatric anterior cruciate ligament tears: Current concepts

Background

Anterior cruciate ligament injury in the child and adolescent patient remains a controversial topic when considering management, especially regarding surgical choices. Treatment variations are seen not just when comparing different countries but also within nations. This arises partly as contemporary treatment is mostly inferred from the adult population who physiologically and in terms of outcomes differ significantly from children. There is an increasing body of evidence for this cohort of patients who have specific challenges and difficulties when determining the optimum treatment.

Methods

Within this article, we will summarize the current evidence for surgical management of anterior cruciate ligament injury for the pediatric patient.

Results and Conclusions

There remain many controversies and gaps inthe treatment of Paediatric Anterior cruciate ligament reconstruction and this high risk cohort continues to cause difficulty in identifying the best mode of surgical management.

Level of evidence

level IV.

Osteochondritis dissecans of the knee: Epidemiology, etiology, and natural history

Osteochondritis dissecans of the knee is a disease that typically affects skeletally immature patients. Clinically manifested with knee pain, limping, and joint disfunction, this condition has remained misunderstood and undervalued for a long period. Although being a rare condition, its awareness is of utmost clinical interest because of the possible severe consequences it can bring when misrecognized or inadequately treated. Its etiology remains unclear and is still debated. Many theories have been proposed, including inflammation, local ischemia, subchondral ossification abnormalities, genetic factors, and repetitive mechanical microtrauma, with a likely interplay of the same. This review article aims to deliver and discuss current and up-to-date concepts on epidemiology, etiology, and natural history of this pediatric condition. Level of evidence: level V.

Pediatric anterior cruciate ligament tears and associated lesions: Epidemiology, diagnostic process, and imaging

The incidence of anterior cruciate ligament injuries in skeletally immature patients has increased in recent years. The gold standard treatment of this type of trauma in children is not yet established. Conservative management may underestimate the risk of new meniscal and chondral tears; on the other hand, a more interventional approach may expose the patient to iatrogenic damage to the growth plate. A correct approach to the skeletally immature patient with knee trauma is therefore essential to guide the decision-making process. This review article aims to present an update on the epidemiology and diagnostic process of pediatric patients with anterior cruciate ligament tears and possible associated injuries. Level of Evidence: V.

Characterization of microRNA Levels in Synovial Fluid from Knee Osteoarthritis and Anterior Cruciate Ligament Tears

This study investigated modifications of microRNA expression profiles in knee synovial fluid of patients with osteoarthritis (OA) and rupture of the anterior cruciate ligament (ACL). Twelve microRNAs (26a-5p, 27a-3p, let7a-5p, 140-5p, 146-5p, 155-5p, 16-5p,186-5p, 199a-3p, 210-3p, 205-5p, and 30b-5p) were measured by real-time quantitative polymerase chain reaction (RT-qPCR) in synovial fluids obtained from 30 patients with ACL tear and 18 patients with knee OA. These 12 miRNAs were chosen on the basis of their involvement in pathological processes of bone and cartilage. Our results show that miR-26a-5p, miR-186-5p, and miR-30b-5p were expressed in the majority of OA and ACL tear samples, whereas miR-199a-3p, miR-210-3p, and miR-205-5p were detectable only in a few samples. Interestingly, miR-140-5p was expressed in only one sample of thirty in the ACL tear group. miR-140-5p has been proposed to modulate two genes (BGN and COL5A1100) that are involved in ligamentous homeostasis; their altered expression could be linked with ACL rupture susceptibility. The expression of miR-30b-5p was higher in OA and chronic ACL groups compared to acute ACL samples. We provide evidence that specific miRNAs could be detected not only in synovial fluid of patients with OA, but also in post-traumatic ACL tears.

Clinical outcomes and complications after anterior cruciate ligament reconstruction with bone-patellar tendon-bone in patient Tanner 3 and 4: a systematic review

BACKGROUND

Clinical outcomes and potential complications associated with Bone-Patellar Tendon-Bone (BPTB) graft in skeletally immature ACL reconstruction (ACLR) are poorly defined. Considering that in Tanner 1-2 patients this kind of graft is not recommended, we focused our systematic review on the evaluation of all the studies in the literature that reported clinical outcomes and rate of complications of the ACLR using BPTB graft in Tanner 3-4 patients.

METHODS

This review was conducted in accordance with the PRISMA statement. PubMed, Cochrane Library, EMBASE and Scopus were examined from 1965 to 2020 using different combinations of the following keywords: "ACL reconstruction", "skeletally immature", "young", "patellar tendon" and "BPTB". The database search yielded 742 studies, on which we performed a primary evaluation. After carrying out a full-text evaluation for the inclusion criteria, 4 studies were included in the final review and assessed using the Newcastle-Ottawa scale. Ninety-six cases with mean age of 14.2 years were reported.

RESULTS

Good stability and functional outcomes were reported with a mean follow-up of 49.5 months. Return to sport rate ranged from 91.7% to 100%. A KT-1000 side-to-side difference higher than 5 mm was observed in five patients (5.2%). No lower limb length discrepancy and angulation were reported. Graft rupture rate was 5.2%.

CONCLUSION

According to these results, BTPB graft could be a good choice in Tanner 3-4 patients who want to achieve their preinjury sport level with a low risk of growth disturbances and graft failure. Further investigations in a wider population are needed.

Skeletally immature patient showed lower graft maturity than skeletally mature patient after ACL reconstruction with a rounded rectangular femoral tunnel

To compare the clinical results and ligamentization of anterior cruciate ligament reconstruction (ACLR) between skeletally immature and mature patients. Two-hundred-and-two patients who underwent primary ACLR were evaluated retrospectively. The clinical outcomes were compared between skeletally immature (immature group 1, n = 27) and mature (control group 1, n = 175) groups. Graft ligamentization of the reconstructed anterior cruciate ligament (ACL) using magnetic resonance imaging (MRI) signal intensity at 6 months postoperatively was compared between immature group 2 (n = 16), which included participants from immature group 1, and control group 2 (n = 32), created by recruiting data-matched controls from control group 1. Immature group 1 had significantly higher revision (14.8%) and pivot shift test positive (22.2%) rates than control group 1 (2.9% and 4.0%, respectively) (P = 0.020 and 0.003, respectively). The signal intensity in immature group 2 were significantly higher at the mid-substance and distal site of the reconstructed ACL than those in control group 2 (P = 0.003 and 0.034, respectively). Skeletally immature patients had higher graft revision and residual rotational laxity rates. Reconstructed ACL in skeletally immature patients showed higher signal intensity on MRI at 6 months postoperatively.