Influence of material properties and boundary conditions on patient-specific models.

Patient-specific finite element models (PSFEM) are becoming more and more used. Different methods for assigning their material properties were studied on PSFEMs of 9 tibias along with the minimal required length of the CT acquisition window. Material properties are generally attributed to the PSFEM using relationships linking the grayscale of CT scans to the elasticity moduli.

Does labral repair have a clinical benefit during arthroscopic treatment of femoro-acetabular impingement? Prospective multicentre study with 2-year follow-up.

Introduction: Hip arthroscopy has emerged as an effective tool for treating labral tears associated with femoro-acetabular impingement (FAI).

Objective: Compare the effectiveness of debridement versus labral repair on functional outcomes at 2 years after hip arthroscopy and evaluate the influence of the repair technique.

Hypothesis: There is no statistical difference in short-term functional outcomes between debridement and repair.

Trabecular Metal Cones Combined With Short Cemented Stem Allow Favorable Outcomes in Aseptic Revision Total Knee Arthroplasty.

Background: The purpose of this study was to compare the functional outcomes and implant survivorship at a minimum of 5 years of follow-up of several reconstruction techniques with or without metaphyseal cone and stems of variable length.

Methods: A retrospective comparative matched analysis was performed from 2 prospectively collected databases. Only patients who underwent revision total knee arthroplasty procedures for aseptic causes using a single design of rotating hinge knee with a minimum of 5 years of follow-up were analyzed.

Ultrasounds could be considered as a future tool for probing growing bone properties.

Juvenile bone growth is well described (physiological and anatomical) but there are still lacks of knowledge on intrinsic material properties. Our group has already published, on different samples, several studies on the assessment of intrinsic material properties of juvenile bone compared to material properties of adult bone. The purpose of this study was finally to combine different experimental modalities available (ultrasonic measurement, micro-Computed Tomography analysis, mechanical compression tests and biochemical measurements) applied on small cubic bone samples in order to gain insight into the multiparametric evaluation of bone quality.

Early-stage knee OA induced by MIA and MMT compared in the murine model via histological and topographical approaches.

Osteoarthritis (OA) is a common degenerative disease whose early management includes promising mechanical treatments. New treatments are initially validated using an animal model in which OA is induced. The MMT (mechanical induction) and MIA (chemical induction) models of OA induction are widespread, but their use to generate early OA is poorly documented.

CAS and PSI increase coronal alignment accuracy and reduce outliers when compared to traditional technique of medial open wedge high tibial osteotomy: a meta-analysis.

Purpose: Medial open-wedge high tibial osteotomy (MOWHTO) is an accepted option in the treatment of medial compartment osteoarthritis of the knee in young and active patients. Functional results are closely correlated to the correction of the mechanical axis of the lower limb. Although several angular and geometrical methods and values have been proposed in the past, the ideal target is still debated.

Managing intra-articular deformity in high Tibial osteotomy: a narrative review.

The joint line convergence angle (JLCA) has a normal range between 0° to 2°, which increases in magnitude depending on the severity and stage of osteoarthritis in the knee.The JLCA represents the interaction of the intra-articular deformity arising from the osteoarthritis and the surrounding soft tissue laxity. Therefore, the JLCA has become a vital parameter in analysing the long leg alignment views for corrective planning before osteotomy surgery.

Posteromedial Opening-Wedge Tibial Osteotomy for Metaphyseal Varus and Abnormal Posterior Slope Correction in Failed Anterior Cruciate Ligament Reconstructions Using a Custom Cutting Guide.

Anterior cruciate ligament reconstruction after graft failure may need associated bone correction to ensure stability of the knee. This article presents a technique of posteromedial opening-wedge osteotomy using a custom cutting guide to correct increased tibial slope and metaphyseal varus deformity after recurrent graft failure. An autograft quadriceps tendon graft was selected for the revision anterior cruciate ligament graft.

Accuracy of the correction obtained after tibial valgus osteotomy. Comparison of the use of the Hernigou table and the so-called classical method.

Introduction: Medial valgus-producing tibial osteotomy (MVTO) is classically used to treat early medial femorotibial osteoarthritis. Long-term results depend on the mechanical femorotibial angle (HKA) obtained at the end of the procedure. A correction goal between 3 and 6° valgus is commonly accepted.

Reverse shoulder-allograft prosthesis composite, with or without tendon transfer, for the treatment of severe proximal humeral bone loss.

Background: The treatment of severe proximal humeral bone loss (PHBL) secondary to tumor resection or failed arthroplasty is challenging. We evaluated the outcomes and complications of reconstruction with reverse shoulder-allograft prosthesis composite (RS-APC), performed with or without tendon transfer.

Methods: An RS-APC procedure was performed in 25 consecutive patients with severe PHBL (>4 cm): 12 after failed reverse shoulder arthroplasty, 5 after failed hemiarthroplasty for fracture, 6 after failed mega-tumor prosthesis placement, and 2 after tumor resection.

Fracture of pyrocarbon humeral head resurfacing implant: a case report.

We report a case of a pyrocarbon humeral head resurfacing implant fracture, occurring 6 years after its implantation, without any obvious trauma or dislocation. Initial radiographs showed a proud and oversized pyrocarbon resurfacing implant. On clinical examination, the patient had a painful and pseudoparalyzed shoulder with subscapularis insufficiency.

Estimation of joint contact pressure in the index finger using a hybrid finite element musculoskeletal approach.

The knowledge of local stress distribution in hand joints is crucial to understand injuries and osteoarthritis occurrence. However, determining cartilage contact stresses remains a challenge, requiring numerical models including both accurate anatomical components and realistic tendon force actuation. Contact forces in finger joints have frequently been calculated but little data is available on joint contact pressures.

Healthy middle-aged Asian and Caucasian populations present with large intra- and inter-individual variations of lower limb torsion.

Purpose: There is a lack of standardization in the measurement of lower limb torsional alignment. Normal values published in the literature are inconsistent. A 3D-CT-scan-based method was used in a healthy population to define the femoral neck version (FNV) and the tibial torsion (TT) and their relationship with demographic parameters.

Knee surgery trends and projections in France from 2008 to 2070.

Introduction: Knee surgery makes up a large share of the orthopedic surgery practice. Data on how this activity has changed over time is not available in France, thus we wanted to do a study to determine 1) how many knee surgeries were performed in France in 2018, 2) how this changed between 2012 and 2018, and 3) how it is projected to change by 2070. The hypothesis is that the number of knee surgeries will increase over the next 50 years.

Bony increased-offset-reverse shoulder arthroplasty: 5 to 10 years' follow-up.

Background: Glenoid lateralization has been shown to be the most imortant factor in maximizing passive range of motion and shoulder stability while preventing scapular impingement and notching. We aimed to evaluate mid- to long-term functional and radiologic outcomes after bony increased-offset-reverse shoulder arthroplasty (BIO-RSA) using a Grammont-style (medialized) humeral implant.

Methods: The study included 143 consecutive shoulders (140 patients; mean age, 72 years) treated with a BIO-RSA for rotator cuff deficiency.

Antimicrobial properties of antibiotic-loaded implants.

Aims: The aim of this study was to compare the ability of tantalum, 3D porous titanium, antibiotic-loaded bone cement, and smooth titanium alloy to inhibit staphylococci in an in vitro environment, based on the evaluation of the zone of inhibition (ZOI). The hypothesis was that there would be no significant difference in the inhibition of methicillin-sensitive or methicillin-resistant (MSSA/MRSA) between the two groups.

Methods: A total of 30 beads made of three different materials (tantalum/3D porous titanium and smooth titanium alloy) were bathed for one hour in a solution of 1 g vancomycin in 20 ml of sterile water for injection (bath concentration: 50 mg/mL).

COVID-19 - ESSKA guidelines and recommendations for resuming elective surgery.

The roadmap to elective surgery resumption after this COVID-19 pandemic should be progressive and cautious. The aim of this paper was to give recommendations and guidelines for resuming elective orthopedic surgery in the safest environment possible. Elective surgery should be performed in COVID-free facilities and hospital stay should be as short as possible.

Neutral alignment resulting from tibial vara and opposite femoral valgus is the main morphologic pattern in healthy middle-aged patients: an exploration of a 3D-CT database.

Purpose: Given the goal of achieving optimal correction and alignment after knee arthroplasty or high tibial osteotomy, literature focusing on the inter-individual variability of the native knee, tibia and femur with regards to the coronal or sagittal alignment is lacking. The aim of this study was to analyse normal angular values in the healthy middle-aged population and determine differences of angular values according to inter-individual features. The first hypothesis was that common morphological patterns may be identified in the healthy middle-aged non-osteoarthritic population.

Long-term results of custom-made femoral stems.

Background: The progress of 3D imaging and manufacturing of implants has made it possible to achieve a custom-made concept in THA. The custom-made cementless femoral stem provides optimal implant stability combined with restoration of the native hip mechanics.

Objective: The purpose of this study was to evaluate the long-term survivorship of custom-made hip femoral stems in two populations of patients undergoing THA: patients under 50 years old (young patients group) and patients with high-grade developmental dysplasia of the hip (DDH group).

Adding a protective screw improves hinge's axial and torsional stability in High Tibial Osteotomy.

Backgrounds: Despite the use of a locking plate a 30% incidence of lateral hinge fracture after Open-Wedge High Tibial Ostetomy was described in the literature. A finite element model was used to analyze if the presence of a hinge-securing screw in the osteotomy area, using Patient Specific Cutting Guides with a locking plate, decreases the stresses within the lateral hinge during compression and torsion.

Methods: A 3D model of a tibial sawbone was used to simulate an opening wedge of 10°.