Adding a protective K-wire during opening high tibial osteotomy increases lateral hinge resistance to fracture.

Purpose: It was hypothesized in this in-vitro study that positioning a K-wire intersecting the cutting plane at the theoretical lateral hinge location would limit the cut depth and help preserve the lateral hinge during the opening of the osteotomy. Objectives were (1) to compare the mechanical resistance of the hinge and the protective effect of leaving the K-wire during the opening procedure (2) to check if the K-wire would limit the depth of the osteotomy.

Methods: An ex-vivo mechanical study, testing 5 pairs of fresh-frozen tibias, was designed.

Estimation of the elastic modulus of child cortical bone specimens via microindentation.

: Non-pathological child cortical bone (NPCCB) studies can provide clinicians with vital information and insights. However, assessing the anisotropic elastic properties of NPCCB remains a challenge for the biomechanical engineering community. For the first time, this paper provides elastic moduli values for NPCCB specimens in two perpendicular directions (longitudinal and transverse) and for two different structural components of bone tissue (osteon and interstitial lamellae).

Long-Term Results of Medial Unicompartmental Knee Arthroplasty for Knee Avascular Necrosis.

Background: Numerous series have documented short and mid-term successes with cemented, metal-backed modern unicompartmental knee arthroplasty (UKA) for avascular osteonecrosis of the knee (AVN). However, data are lacking regarding long-term implant fixation and patient function. The aim of this study is therefore to evaluate the long-term clinical outcome and implant survivorship of patients who underwent UKA for medial knee osteonecrosis (ON).

Assessment of elastic coefficients of child cortical bone using resonant ultrasound spectroscopy.

The assessment of the anisotropic elastic properties of non-pathological child cortical bone remains a challenge for the biomechanical engineering community and an important clinical issue. Resonant ultrasound spectroscopy (RUS) can be used to determine bone stiffness coefficients from the mechanical resonances of bone specimens. Here, a RUS protocol was used on 7 fibula specimens from children (mean age 14 ± 3 years) to estimate the whole elastic stiffness tensor of non-pathological child cortical bone considered as orthotropic.

Ten-year epidemiological study in an orthopaedic and trauma surgery centre: Are there risks involved in increasing scheduled arthroplasty volume without increasing resources?

Background: Current trends in patient management include decreasing hospital stay lengths and reductions in available material and human resources. A shortening of hospital stays in university hospitals has been documented over the last decade. However, to our knowledge, no study has assessed possible relationships linking shorter stays to staffing levels or complication rates.

Update on the supply and use of allografts in locomotor system pathologies in France.

Unlabelled: Allografts are increasingly used in orthopedics. The main aim of the present study was to map the use of locomotor system allografts in France between 2012 and 2016. The study hypothesis was that there are great differences in the distribution and activity of tissue banks and graft preservation procedure quality, failing to meet national requirements.

Articular-surface-based automatic anatomical coordinate systems for the knee bones.

Increasing use of patient-specific surgical procedures in orthopaedics means that patient-specific anatomical coordinate systems (ACSs) need to be determined. For knee bones, automatic algorithms constructing ACSs exist and are assumed to be more reliable than manual methods, although both approaches are based on non-unique numerical reconstructions of true bone geometries. Furthermore, determining the best algorithms is difficult, as algorithms are evaluated on different datasets.

Femoral malrotation from diaphyseal fractures results in changes in patellofemoral alignment and higher patellofemoral stress from a finite element model study.

Background: Malrotation of the femur is a frequent complication in the management of a diaphyseal fracture. It is often responsible for pain and adverse functional results. Among these complications, contact stress effects on the patellofemoral joint are recognized as predictive factors of impaired results.

Are three-dimensional patient-specific cutting guides for open wedge high tibial osteotomy accurate? An in vitro study.

Background: The aim of this in vitro study was to assess the accuracy of three-dimensional patient-specific cutting guides for open wedge high tibial osteotomy (OWHTO) to provide the planned correction in both frontal and sagittal planes.

Methods: Ten cadaveric tibias underwent OWHTO performed using a patient-specific cutting guide based on 3D preoperative planning. An initial CT scan of the tibias was performed, and after segmentation, 3D geometrical models of the pre-OWHTO tibias were obtained.

Minimum 10-Year Outcome of One-Stage Total Hip Arthroplasty Without Subtrochanteric Osteotomy Using a Cementless Custom Stem for Crowe III and IV Hip Dislocation.

Background: Options for total hip arthroplasty (THA) in high dislocated hips include subtrochanteric osteotomy (STO), high hip center positioning, and 2-stage surgery with progressive lowering using an external fixator before THA. We described the long-term results of 1-stage THA performed without STO, using a cementless customized stem associated if necessary with sequential tenotomies and/or greater trochanteric osteotomy.

Methods: Ninety-eight consecutive THA without STO were performed using this technique.

No Benefit of Computer-assisted TKA: 10-year Results of a Prospective Randomized Study.

Background: Previously published studies reported benefits of computer-assisted surgery (CAS) in terms of radiographic implant position in TKA, but whether these improvements result in clinically important survival differences or functional differences that a patient might perceive at a minimum 10-year followup remains largely unknown.

Questions/purposes: We performed a prospective randomized trial and asked whether CAS (1) improved survival free from aseptic loosening; and (2) demonstrated any clear difference in patient-reported outcomes at latest followup using validated outcome measures at minimum 10-year followup.

Methods: Between January 2004 and December 2005, 80 patients scheduled for TKA were randomly assigned either to the CAS group or to the conventional technique group by the Hospital Informatics Department.

Long-term results of custom cementless-stem total hip arthroplasty performed in hip fusion.

Introduction: Due to complex anatomical considerations, results of cementless-stem total hip arthroplasty (THA) in hip fusion remain controversial compared with conventional THA. We therefore aimed to analyse 3D anatomy of the fused hip based on pre-operative computed tomography (CT) scans, functional outcomes based on the Harris Hip Score (HHS) and the Hip Disability and Osteoarthritis Outcome Score (HOOS), modifications of hip anatomy based on post-operative standardised radiography, and determine complication rate and long-term survival based on Kaplan-Meier analysis.

Methods: We retrospectively studied 23 hips that underwent conversion of a fused hip to THA using a 3D CT scan-based custom titanium (Ti alloy hypoxyapetite (HA)-coated stem.

An Efficient and Reproducible Protocol for Distraction Osteogenesis in a Rat Model Leading to a Functional Regenerated Femur.

This protocol describes the use of a newly developed external fixator for distraction osteogenesis in a rat femoral model. Distraction osteogenesis (DO) is a surgical technique leading to bone regeneration after an osteotomy. The osteotomized extremities are moved away from each other by gradual distraction to reach the desired elongation.

First-line management of distal humerus fracture by total elbow arthroplasty in geriatric traumatology: Results in a 21-patient series at a minimum 2years' follow-up.

Introduction: Total elbow arthroplasty (TEA) is one option in distal humerus fracture in elderly osteoporotic patients.

Hypothesis: The study hypothesis was that, in patients aged 70years or more, TEA provides functional results and ranges of motion compatible with everyday activity, with a complications rate equal to or lower than with internal fixation, and no loss of autonomy or cognitive impairment.

Material And Methods: In this retrospective study, 21 patients receiving TEA for distal humerus fracture were included.

Biomechanical causes of trapeziometacarpal arthroplasty failure.

Trapeziometacarpal joint prosthesis revision has been widely reported, mainly due to loosening of the trapezium cup. Our hypothesis is that current prostheses do not sufficiently respect the kinematics of this joint. CT scan acquisitions enabled us to determine the position of the first metacarpal relative to the trapezium in three different characteristic postures, in subjects in different stages of arthrosis.

Is the subscapularis normal after the open Latarjet procedure? An isokinetic and magnetic resonance imaging evaluation.

Background: The Latarjet procedure is considered to be a violation of the subscapularis muscle. This study evaluated the postoperative status of the subscapularis through isokinetic and magnetic resonance imaging analysis after splitting. We hypothesized that compared with a healthy contralateral shoulder, there would be satisfactory recovery of subscapularis strength at the cost of some fatigability and some mild fatty infiltration.

Correlative Analysis of Vertebral Trabecular Bone Microarchitecture and Mechanical Properties: A Combined Ultra-high Field (7 Tesla) MRI and Biomechanical Investigation.

Study Design: High-resolution imaging and biomechanical investigation of ex-vivo vertebrae.

Objective: The aim of this study was to assess bone microarchitecture of cadaveric vertebrae using ultra-high field (UHF) 7 Tesla magnetic resonance imaging (MRI) and to determine whether the corresponding microarchitecture parameters were related to bone mineral density (BMD) and bone strength assessed by dual-energy x-ray absorptiometry (DXA) and mechanical compression tests.

Summary Of Background Data: Limitations of DXA for the assessment of bone fragility and osteoporosis have been recognized and criteria of microarchitecture alteration have been included in the definition of osteoporosis.

Stem cell mechanical behaviour modelling: substrate's curvature influence during adhesion.

Recent experiments hint that adherent cells are sensitive to their substrate curvature. It is already well known that cells behaviour can be regulated by the mechanical properties of their environment. However, no mechanisms have been established regarding the influence of cell-scale curvature of the substrate.

Tribology of flexible and sliding spinal implants: Development of experimental and numerical models.

New fusionless devices are being developed to get over the limits of actual spinal surgical treatment, based on arthrodesis. However, due to their recentness, no standards exist to test and validate those devices, especially concerning the wear. A new tribological first approach to the definition of an in vitro wear protocol to study wear of flexible and sliding spinal devices is presented in this article, and was applied to a new concept.

Use of porous tantalum components in Paprosky two and three acetabular revision. A minimum five-year follow-up of fifty one hips.

Introduction: Recent studies have reported short-term favourable results of tantalum-made components in acetabular revisions with bone loss. However, there is a lack of information regarding the mid to long-term results of such components.

Objectives: The objective of this study was to analyse the outcome and survivorship of acetabular revision hip arthroplasty using tantalum components for loosening associated with bone loss at a minimum of five-year follow-up.

A dynamic study of the anterior cruciate ligament of the knee using an open MRI.

Recent anatomical and radiological studies of the anterior cruciate ligament (ACL) suggest the ACL length and orientation change during knee flexion, and an open MRI sequencing during knee flexion enables a dynamic ACL analysis. This study's goal is to describe a normal ACL using a 1T open MRI and, in particular, variations in length and insertion angles at different degrees of flexion. Twenty-one volunteers with clinically healthy knees received a dynamic MRI with their knees in hyperextension, neutral position, and flexed at 45° and 90° angles.

Better satisfaction of patients operated on anterior cruciate ligament reconstruction in outpatient setting. A prospective comparative monocentric study of 60 cases.

Introduction: The purpose of this study was to compare satisfaction, clinical scores, and complications of patients operated on anterior cruciate ligament reconstruction (ACLR) in outpatient setting compared to patients operated in the conventional hospitalization.

Patients And Methods: This prospective non-randomized study compared 30 patients (mean age 31 ± 9 years) operated on outpatient setting for an isolated ACLR matched 1:1 according to age, gender, body mass index, delay to surgery, and preoperative clinical score (IKDC) to 30 patients operated for an ACLR in our conventional hospitalization department during the same period. All the patients were operated on by the same surgeon.