Contactless femoral implant stability monitoring in cementless total hip arthroplasty, A step towards clinical implementation.

The clinical implementation of currently used devices for intraoperative fixation monitoring of femoral implants via vibration-based methods in cementless total hip arthroplasty is challenging, due to practical and regulatory issues. Motivated by the effectiveness of electromagnetic excitation in similar dental applications, this study investigates the use of electromagnetic excitation for femoral implant stability monitoring during cementless total hip arthroplasty. The results obtained from electromagnetic excitation were largely consistent with reference results obtained through impact excitation, with a Pearson Correlation Coefficient of 0.

Advanced quantitative 3D imaging improves the reliability of the classification of acetabular defects.

Introduction: Classifying complex acetabular defects in revision total hip arthroplasty (THA) by means of conventional radiographs comes with significant limitations. Statistical shape modelling allows the virtual reconstruction of the native pelvic morphology, hereby enabling an analytic acetabular defect assessment. Our objective was to evaluate the effect of advanced imaging augmented with analytic representations of the defect on (1) intra- and inter-rater reliability, and (2) up- or downscaling of classification scores when evaluating acetabular defects in patients undergoing revision THA.

Development of an Instrument to Assess the Stability of Cementless Femoral Implants Using Vibration Analysis During Total Hip Arthroplasty.

Objective: The level of primary implant fixation in cementless total hip arthroplasty is a key factor for the longevity of the implant. Vibration-based methods show promise for providing quantitative information to help surgeons monitor implant fixation intraoperatively. A thorough understanding of what is driving these changes in vibrational behavior is important for further development and improvement of these methods.

The morphological variation of acetabular defects in revision total hip arthroplasty-A statistical shape modeling approach.

Classification and evaluation of acetabular defects remain challenging and are primarily based on qualitative classification methods. That is because quantitative techniques describing variations of acetabular defects and accompanying bone loss volume are not available. This study introduces a new method based on statistical shape models (SSMs) to quantitively describe acetabular defects.

Intra-Articular Hyaluronic Acid Injections Less Than 6 Months Before Total Hip Arthroplasty: Is It Safe? A Retrospective Cohort Study in 565 Patients.

Background: Intra-articular hyaluronic acid (IAHA) can be injected into an osteoarthritic hip joint to reduce pain and to improve functionality. Several studies report IAHA to be safe, with minor adverse effects that normally disappear spontaneously within a week. However, intra-articular corticosteroids prior to total hip arthroplasty (THA) have been associated with increased infection rates.

The Use of a Vibro-Acoustic Based Method to Determine the Composite Material Properties of a Replicate Clavicle Bone Model.

Replicate bones are widely used as an alternative for cadaveric bones for in vitro testing. These composite bone models are more easily available and show low inter-specimen variability compared to cadaveric bone models. The combination of in vitro testing with in silico models can provide further insights in the evaluation of the mechanical behavior of orthopedic implants.

Acoustic analysis to monitor implant seating and early detect fractures in cementless THA: An in vivo study.

The initial stability of cementless total hip arthroplasty (THA) implants is obtained by an interference fit that allows osseointegration for a long term secondary stability of the implant. Yet, finding the insertion endpoint that corresponds to an appropriate initial stability is currently often based on a number of subjective experiences of the orthopedic surgeon, which can be challenging. In order to assist the orthopedic surgeons in their pursuit to find this optimal initial stability, this study aims to determine whether the analysis of sound that results from the implant insertion hammer blows can be used to objectively monitor the insertion process of cementless THA implants.

Accurate reconstructions of pelvic defects and discontinuities using statistical shape models.

Treatment of large acetabular defects and discontinuities remains challenging and relies on the accurate restoration of the native anatomy of the patient. This study introduces and validates a statistical shape model for the reconstruction of acetabular discontinuities with severe bone loss through a two-sided Markov Chain Monte Carlo reconstruction method. The performance of the reconstruction algorithm was evaluated using leave-one-out cross-validation in three defect types with varying severity as well as severe defects with discontinuities.

Comparison of Constrained Acetabular Components and Dual Mobility Cups in Revision Total Hip Arthroplasty: A Literature Review.

Recurrent instability remains a common cause of failure after revision total hip arthroplasty (THA). Dual mobility (DM) cups and designs with constrained acetabular liners (CAL) have both been developed to help overcome this challenge. The aim of this report is to compare safety and efficacy outcomes of both designs based on the literature.

Two Different Methods to Measure the Stability of Acetabular Implants: A Comparison Using Artificial Acetabular Models.

The total number of total hip arthroplasties is increasing every year, and approximately 10% of these surgeries are revisions. New implant design and surgical techniques are evolving quickly and demand accurate preclinical evaluation. The initial stability of cementless implants is one of the main concerns of these preclinical evaluations.

To cement or not to cement acetabular cups in total hip arthroplasty: a systematic review and re-evaluation.

Introduction: Total Hip Arthroplasty (THA) in the treatment of primary osteoarthritis of the hip has evolved to a very safe and cost-effective intervention with revision rates below 5% after 10 years. To this day, however, controversy remains on whether or not to cement the acetabular cup.

Methods: A comprehensive PubMed search of the English literature for studies published between 2007 and 2018 was performed.

Pinnacle® modular metal-on-metal articulation in primary total hip arthroplasty: mid-term results of 195 cases.

Studies concerning Pinnacle® modular metal-on- metal (MoM) total hip arthroplasty (THA) show better results than for most other MoM THAs. The goal of this study was to report on the revision rate, clinical outcome and metal ion levels regarding this specific prosthesis. Retrospectively selected patients were evaluated clinically, and Visual Analogue Score for pain (VAS), Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Score (HOOS) were determined.

Modal frequency and shape curvature as a measure of implant fixation: A computer study on the acetabular cup.

Modal parameters are often investigated in order to assess the initial fixation of an implant. Most of studies are focused on the natural frequencies and frequency response function. Usually the femoral stem is tested although the acetabular cup fixation is important as well.

Development of an acoustic measurement protocol to monitor acetabular implant fixation in cementless total hip Arthroplasty: A preliminary study.

In cementless total hip arthroplasty (THA), the initial stability is obtained by press-fitting the implant in the bone to allow osseointegration for a long term secondary stability. However, finding the insertion endpoint that corresponds to a proper initial stability is currently based on the tactile and auditory experiences of the orthopedic surgeon, which can be challenging. This study presents a novel real-time method based on acoustic signals to monitor the acetabular implant fixation in cementless total hip arthroplasty.

A biomechanical testing system to determine micromotion between hip implant and femur accounting for deformation of the hip implant: Assessment of the influence of rigid body assumptions on micromotions measurements.

Background: Accurate pre-clinical evaluation of the initial stability of new cementless hip stems using in vitro micromotion measurements is an important step in the design process to assess the new stem's potential. Several measuring systems, linear variable displacement transducer-based and other, require assuming bone or implant to be rigid to obtain micromotion values or to calculate derived quantities such as relative implant tilting.

Methods: An alternative linear variable displacement transducer-based measuring system not requiring a rigid body assumption was developed in this study.

Determination of replicate composite bone material properties using modal analysis.

Replicate composite bones are used extensively for in vitro testing of new orthopedic devices. Contrary to tests with cadaveric bone material, which inherently exhibits large variability, they offer a standardized alternative with limited variability. Accurate knowledge of the composite's material properties is important when interpreting in vitro test results and when using them in FE models of biomechanical constructs.

Revival of pure titanium for dynamically loaded porous implants using additive manufacturing.

Additive manufacturing techniques are getting more and more established as reliable methods for producing porous metal implants thanks to the almost full geometrical and mechanical control of the designed porous biomaterial. Today, Ti6Al4V ELI is still the most widely used material for porous implants, and none or little interest goes to pure titanium for use in orthopedic or load-bearing implants. Given the special mechanical behavior of cellular structures and the material properties inherent to the additive manufacturing of metals, the aim of this study is to investigate the properties of selective laser melted pure unalloyed titanium porous structures.

Additively manufactured porous tantalum implants.

The medical device industry's interest in open porous, metallic biomaterials has increased in response to additive manufacturing techniques enabling the production of complex shapes that cannot be produced with conventional techniques. Tantalum is an important metal for medical devices because of its good biocompatibility. In this study selective laser melting technology was used for the first time to manufacture highly porous pure tantalum implants with fully interconnected open pores.

Bone regeneration performance of surface-treated porous titanium.

The large surface area of highly porous titanium structures produced by additive manufacturing can be modified using biofunctionalizing surface treatments to improve the bone regeneration performance of these otherwise bioinert biomaterials. In this longitudinal study, we applied and compared three types of biofunctionalizing surface treatments, namely acid-alkali (AcAl), alkali-acid-heat treatment (AlAcH), and anodizing-heat treatment (AnH). The effects of treatments on apatite forming ability, cell attachment, cell proliferation, osteogenic gene expression, bone regeneration, biomechanical stability, and bone-biomaterial contact were evaluated using apatite forming ability test, cell culture assays, and animal experiments.

Pinnacle revision cup in acetabular surgery results at 2 to 5 years.

Uncemented revision cups are widely used in revision hip arthroplasty; they have shown good results. We report the the short term outcome with the cementless Pinnacle revision cup. All acetabular revisions using a Pinnacle revision cup between January 2007 and March 2010 were included.

Two-stage revision of an infected total hip arthroplasty: a follow-up of 136 patients.

Background And Purpose: Periprosthetic infection of a total hip arthroplasty (THA) is commonly treated with a two-stage revision procedure. After resection of the infected THA and placement of a cement spacer loaded with antibiotics, a THA is inserted at a second procedure to restore hip function and mobility. Revision surgery carries a significant risk of complications.

Outcome of custom-made IMP femoral components of total hip arthroplasty: a follow-up of 15 to 22 years.

A total of 1659 primary THAs using a cemented custom-made intra-operative manufactured prosthesis (IMP)-stem were studied. The end point for survival was defined as revision of the stem for any reason. Revision arthroplasty was performed in 49 cases.

A modified custom-made triflanged acetabular reconstruction ring (MCTARR) for revision hip arthroplasty with severe acetabular defects.

The treatment of extensive acetabular bone loss and pelvic discontinuity in revision total hip arthroplasty remains challenging. We report our preliminary experience with the modified custom-made triflanged acetabular reconstruction ring (MCTARR) in the management of such situations. The MCTARR is a custom-made metal reinforcement ring with a trabecular surface to encourage bone ingrowth and a bulky trabecular metal augmentation to fill the acetabular defects, designed to achieve initial and long-term stability.

Hyaluronic acid in the treatment of knee osteoarthritis: a systematic review and meta-analysis with emphasis on the efficacy of different products.

Background: Although accepted as a conservative treatment option for knee osteoarthritis, the debate about the effectiveness of intra-articular treatment with hyaluronic acid (HA) is still ongoing because of contrasting outcomes in different clinical studies. Several well designed clinical studies showed a significant improvement in pain at follow-up compared with baseline but no significant improvement comparing the efficacy of HA with placebo (saline) or with other conservative treatment options. Notwithstanding the effectiveness of different types of intra-articular HA products, the question of whether one HA product is better than another is still unanswered.

Inverted cup prosthesis to treat recurrent hip dislocation in frail elderly patients.

Recurrent hip dislocation has become an increasing problem in patients who had multiple component revision in total hip arthroplasty. These are often frail elderly patients with loss of constraining soft tissue envelope around the hip and an excessive weakness of the abductor mechanism. We present a simple technique for open reduction of a dislocated hip using a custom-made fully constrained construct with potential for preserving the well fixed femoral implant and parts of the acetabular component.