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Patient factors (notably high tibial slope and narrow femoral intercondylar notch width) and surgical factors (including meniscus treatment and anterior cruciate ligament [ACL] tunnel position) contribute to ACL reconstruction failure. The number one cause of failure is a misplaced ACL femoral tunnel. Tunnel malposition leads to a higher incidence of postoperative meniscal lesions, inferior clinical outcomes, and higher revision rates. [ABSTRACT FROM AUTHOR]

Verletzungen des vorderen Kreuzbandes (VKB) bei Kindern und Jugendlichen sind eine bedeutsame gesundheitliche und ökonomische Belastung und ihre Inzidenz steigt schneller als die in der erwachsenen Bevölkerung. Diese Verletzung beeinträchtigt die Lebensqualität, indem sie sich auf die Entwicklung des Kniegelenkes ebenso wie auf seine zukünftige Funktionalität auswirkt und zur frühzeitigen Entwicklung einer Arthrose führen kann. Aufgrund des jungen Alters haben diese Patienten zusätzlich ein erhöhtes Risiko für sekundäre intraartikuläre Folgeschäden und erneute Verletzungen des VKB. Die geringe Anzahl kindlicher VKB-Verletzungen in einzelnen Krankenhäusern macht internationale multizentrische Studien notwendig, um aussagekräftige prospektive Daten und Langzeitergebnisse in diesem jungen Patientenkollektiv zu erfassen. Aktuell fehlt es an qualitativ hochwertigen Studien zur Behandlung einer kindlichen VKB-Ruptur und die Evidenzlage aktueller Behandlungsempfehlungen ist unzureichend. Aus diesem Grund entstand 2013 die Initiative zur Erfassung von Verletzungen des vorderen Kreuzbandes bei Kindern und Jugendlichen (Paediatric Anterior Cruciate Ligament Monitoring Initiative, PAMI). Dieses Register dient der Sammlung und Analyse von Daten zur Diagnostik und Behandlung von VKB-Verletzungen im Kindes- und Jugendalter und soll eine Grundlage für die Erstellung internationaler evidenzbasierter Leitlinien liefern. Seit 2018 werden für das PAMI-Register Patienten mit einem Skelettalter von 8-14 Jahren bei Mädchen beziehungsweise 8-16 Jahren bei Jungen in verschiedenen internationalen Zentren erfasst, wobei die Zahl der Rekrutierungszentren ebenso wie die Patientenzahl stetig ansteigen. Die Auswertung der Angaben aus den ersten drei Jahren des Projektes liefert bereits aussagekräftige epidemiologische Daten und erste Trends. Es zeigt sich, dass das Projekt international gut anerkannt wurde. Eine zukünftige Herausforderung liegt in der langfristigen Etablierung der PAMI und die Verbreitung der wissenschaftlichen Erkenntnisse. Anterior cruciate ligament (ACL) injuries in children and adolescents are a relevant health and economic burden and their incidence increases at a higher rate than in adults. These injuries compromise the quality of life, affect the development of the knee joint as well as its future functionality, and may lead to early onset of osteoarthritis. Because of their young age, these patients are furthermore at high risk for secondary intraarticular soft tissue damage and re-injury of the ACL. The relatively small number of pediatric ACL injuries in single hospitals, necessitates international multicenter studies to collect meaningful prospective data and long-term outcomes in a young patient population. As a result, there are few high-quality studies on the treatment of pediatric ACL rupture, and the evidence base of current treatment recommendations is insufficient. Thus, the Paediatric Anterior Cruciate Ligament Monitoring Initiative (PAMI) was created in 2013. The registry is designed to collect and analyze data on the diagnosis and treatment of ACL injuries in children and adolescents and to provide a basis for the development of international evidence-based guidelines. Since 2018, patients with a skeletal age of 8-14 years in girls and 8-16 years in boys, respectively, have been recruited for the PAMI registry in various international centers, and the number of recruiting centers as well as the number of patients is increasing constantly. Analysis of the data from the first three years of the project provides epidemiological data and suggests initial trends. It is evident that the project is well established and in international demand. A future challenge is to ensure the long-term durability of PAMI and the dissemination of scientific findings. [ABSTRACT FROM AUTHOR]

Revision anterior cruciate ligament reconstruction (ACL-R) is made challenging by the frequent presence of rotatory instability, tunnel malpositioning and widening, and limited autograft options. Lateral extra-articular tenodesis (LET), alternative tunnel routing, and the use of allograft tissue can be used to manage these challenges. This Technical Note describes revision ACL-R using the over-the-top (OTT) technique with Achilles tendon allograft with concomitant LET. The surgical approach involves routing the graft around the posterior aspect of the lateral femoral condyle, and then deep to the iliotibial band to a site just medial to Gerdy's tubercle, with staple fixation on the lateral femur for the ACL-R and anterolateral tibia for the LET. The OTT technique with LET provides a versatile approach for the management of failed ACL-R by circumventing challenges in revision ACL-R and addressing rotatory instability, a contributing factor to prior graft failure. [Display omitted] [ABSTRACT FROM AUTHOR]

The medial collateral ligament (MCL) and the posteromedial corner (PMC) of the knee are essential structures for maintaining medial knee stability. Chronic MCL instability is infrequent but can necessitate surgical intervention. Various surgical techniques have been described, but they often involve the use of tibial tunnels, which may complicate concurrent ligament reconstructions. This study aims to present a minimally invasive double-bundle PMC reconstruction technique that avoids the use of tibial tunnels. Knee evaluation was performed using standard clinical tests and 1.5-Tesla magnetic resonance imaging. Patients with grade III Hughston MCL injuries were considered for surgery. The technique employs either an autologous semitendinosus graft or a fresh-frozen allograft, usually tibialis anterior, to reconstruct both the superficial MCL and the posterior oblique ligament. The technique described avoids the use of tibial tunnels, preserving tibial bone stock for any future procedures. The graft is secured at the femoral and tibial insertions using bioabsorbable interference screws and titanium staples, respectively. Our minimally invasive double-bundle PMC reconstruction technique offers a feasible and effective solution for patients with chronic medial knee instability. It is particularly beneficial for patients requiring multiple ligament reconstructions, as it avoids tunnel collision and preserves tibial bone stock. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: To compare, at long-term follow-up, the clinical outcomes and failures of collagen and polyurethane meniscal scaffolds for the treatment of partial meniscal defects.Methods: Patients affected by partial meniscal defect with intact anterior and posterior meniscal attachments and an intact rim at the circumference of the missing meniscus were included, treated with a collagen meniscal implant or with polyurethane scaffold, and clinically evaluated by analysis of the subjective International Knee Documentation Committee score, the visual analog scale score for the evaluation of knee function and symptoms, and the Tegner score to assess the activity level.Results: After 3 patients dropped out, a total of 47 patients, comprising 31 men and 16 women, with a mean age of 43 ± 14.1 years and mean body mass index of 25 ± 1.4, were clinically evaluated up to a mean of 10 years' follow-up. The International Knee Documentation Committee score improved from 42.9 ± 15.9 to 67.4 ± 12.4 (P < .0005) in the polyurethane implant group and from 46.8 ± 16.7 to 62.1 ± 22.6 (P < .0005) in the collagen meniscal implant group. The visual analog scale score decreased significantly from baseline values of 5.4 ± 2.3 and 4.4 ± 1.7, to 3.4 ± 2.5 and 2.7 ± 2.4, respectively, at final follow-up in the polyurethane implant (P = .002) and collagen meniscal implant (P < .0005) groups. The Tegner score improved in both groups without reaching the preinjury activity level. No significant differences in the scores were found between the polyurethane and collagen scaffold groups. A total of 10 implants failed, 5 per group, for a cumulative failure rate of 21.3%, with no differences between the 2 scaffolds.Conclusions: The long-term comparison showed positive and similar results for both polyurethane- and collagen-based meniscal scaffolds, with an implant survival rate of about 80% at 10 years of follow-up and no differences in terms of pain, function, and activity level.Level Of Evidence: Level IV, case-control comparative study. [ABSTRACT FROM AUTHOR]

Within the human tibiofemoral joint, meniscus plays a key role due to its peculiar time-dependent mechanical characteristics, inhomogeneous structure and compositional features. To better understand the pathophysiological mechanisms underlying this essential component, it is mandatory to analyze in depth the relationship between its structure and the function it performs in the joint. Accordingly, the aim of this study was to evaluate the behavior of both solid and fluid phases of human meniscus in response to compressive loads, by integrating mechanical assessment and histological analysis. Cubic specimens were harvested from seven knee lateral menisci, specifically from anterior horn, pars intermedia and posterior horn; unconfined compressive tests were then performed according to three main loading directions (i.e., radial, circumferential and vertical). Fibril modulus, matrix modulus and hydraulic permeability of the tissue were thence estimated through a fibril-network-reinforced biphasic model. Tissue porosity and collagen fibers arrangement were assessed through histology for each region and related to the loading directions adopted during mechanical tests. Regional and strain-dependent constitutive parameters were finally proposed for the human lateral meniscus, suggesting an isotropic behavior of both the horns, and a transversely isotropic response of the pars intermedia. Furthermore, the histological findings supported the evidences highlighted by the compressive tests. Indeed, this study provided novel insights concerning the functional behavior of human menisci by integrating mechanical and histological characterizations and thus highlighting the key role of this component in knee contact mechanics and presenting fundamental information that can be used in the development of tissue-engineered substitutes. This work presents an integration to the approaches currently used to model the mechanical behavior of the meniscal tissue. This study assessed in detail the regional and directional contributions of both the meniscal solid and fluid phases during compressive response, providing also complementary histological evidence. Within this updated perspective, both knee computational modeling and meniscal tissue engineering can be improved to have an effective impact on the clinical practice. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Lateral unicompartmental knee arthroplasty (UKA) is a viable solution for isolated lateral compartment arthritis. Several prosthetic designs are available such as fixed-bearing metal-backed (FB M-B), fixed-bearing all-polyethylene (FB A-P), and mobile-bearing metal-backed (MB M-B) implants. The purpose of this meta-analysis is to compare failure rates of different prosthetic designs.Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review was conducted using 4 databases (MEDLINE, EMBASE, Cochrane, and PubMed) to identify all studies that investigate outcomes of lateral UKA. Twenty-one studies met the inclusion criteria, and failure rates were compared by implant type and follow-up time separately in order to assess potential confounding factors. Two separate analyses have been performed among different implant designs (FB M-B vs FB A-P vs MB M-B) and different follow-ups (<5 years, between 5 and 10 years, >10 years).Results: The failure rate of FB M-B lateral UKA was significantly lower compared to other lateral UKA designs present in the market (0.8% vs 8.6% and 7.1% for FB M-B, FB A-P, and MB M-B, respectively). No significative difference among groups has been detected when comparing all implants with regard to follow-up time.Conclusion: Considering actual evidence, for a surgeon approaching lateral UKA, the FB M-B design is preferable, given the lower failure rates and subsequently a longer implant survivorship. [ABSTRACT FROM AUTHOR]

Background: A fully personalised combination of Gait Analysis (GA), including Ground Reaction Force (GRF), and patient-specific knee joint morphology has not yet been reported. This can provide valuable biomechanical insight in normal and pathological conditions. Abnormal knee varus results in medial knee condylar hyper-compression and osteoarthritis, which can be prevented by restoring proper condylar load distribution via High Tibial Osteotomy (HTO).Research Question: This study was aimed at reporting on an original methodology, merging GA, GRF and Computer-Tomography (CT) to depict a patient-specific representation of the knee mechanical condition during locomotion. It was hypothesised that HTO results in a lateralized pattern of GRF with respect to the tibial plateau.Methods: Four patients selected for HTO received clinical, radiological and instrumental examinations, pre- and post-operatively at 6-month follow-up. GA was performed during level walking and more demanding motor tasks using a 9-camera motion-capture system, combined with two force platforms, and an established protocol. Additional skin markers were positioned around the tibial-plateau rim. Weight-bearing CT scans of the knee were collected while still wearing these markers. Proximal tibial and marker morphological models were reconstructed. The markers from CT reconstruction were then registered to the corresponding trajectories as tracked by GA data. Resulting registration matrices were used to report GRF vectors on the plane best matching the tibial-plateau model and the intersection paths were calculated.Results and Significance: The registration procedure was successfully executed, with a max registration error of about 3 mm. GRF intersection paths were found medially to the tibial plateau pre-op, and lateralized post-op, thus much closer to the knee centre, as expected after HTO. The exploitation of the present methodology offers personalised quantification of the original mechanical misalignment and of the effect of surgical correction which could enhance diagnostics and planning of HTO as well as other knee treatments. [ABSTRACT FROM AUTHOR]

Background: The main goal of the surgical correction of the hallux valgus is the morphological correction associated with the functional rebalancing of the first ray. The aim of this triple-blinded, randomized controlled study was to show the efficacy of piezosurgery in performing distal linear osteotomy of the first metatarsal bone in HV correction, in terms of clinical and radiological outcomes at 1-year final follow up.Methods and Materials: This study was performed collecting prospectively pre-operative and post-operative data for all patients. 34 patients were included in the trial and were randomly allocated (1:1) in a Piezoelectric Group (PG) that involved the use of piezoelectric tools and in a Control Group (CG) that provided for the use of a traditional oscillating saw. In both groups, all patients were treated with a distal linear osteotomy of the first metatarsal bone. Clinical and radiographic assessments were performed.Results: The AOFAS score between the two groups was similar pre-operatively and during the follow-up period, with a slight superiority in the PG at each evaluation. The osteotomy surgical time was registered for both groups. Among the endpoints of the study, the radiological bone healing time was independently assessed by a radiologist that reported a lower mean value in the piezoelectric group compared with the control group.Conclusions: This trial has shown that piezoelectric surgery is not inferior to traditional methods from the clinical-functional point of view, but can even lead to an evident reduction of bone healing time with a statistical significance.Level Of Evidence: Level I. [ABSTRACT FROM AUTHOR]