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The aim of this study was to evaluate the suitability of the tapered cone stem in total hip arthroplasty (THA) in patients with excessive femoral anteversion and after femoral osteotomy.

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This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged less than 50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component.

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There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA).

Fracture risks are the most common argument against the use of Ceramic on ceramic (CoC) hip implants. Question: is ceramic material at risk in case of severe local trauma?. Over a long period, we tried to identify patients with a CoC prosthesis (Ceraver Osteal°)who did sustain a trauma. This was conducted in three different institutions. Eleven patients were found: 9 males and 2 females aged 17 to 70 years at time of index surgery. Accident occurred 6 months to 15 years after index: one car accident, five motorcycle accident, five significant trauma after a fall, including one ski board accident. Consequences of these trauma were: six fractures of the acetabulum with socket loosening in 4 that needed revision, two femoral shaft fracture, one orifed and one stem exchanged, one traumatic hip dislocation associated to loosening of the socket revised at 10 years, and one traumatic loosening of the socket. Ten had no consequence on ceramic integrity. One experienced a fracture of the patella from a dashboard trauma, a liner shipping was discovered during socket revision 2 years later. This is the only case of possible relation between trauma and ceramic fracture. In a more recent longitudinal study on 1856 CoC prosthesis performed from 2010 to 2021, 29 severe traumas were identified with no consequence on Ceramic material. From this limited case study, it can be assumed that Pure Alumina Ceramic well designed and manufactured, will not break after a significant trauma

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The Exeter V40 cemented femoral stem was first introduced in 2000. The largest single-centre analysis of this implant to date was published in 2018 by Westerman et al. Excellent results were reported at a minimum of ten years for the first 540 cases performed at the designer centre in the Exeter NHS Trust, with stem survivorship of 96.8%. The aim of this current study is to report long-term outcomes and survivorship for the Exeter V40 stem in a non-designer centre.

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To compare long-term survival of all-cemented and hybrid total hip arthroplasty (THA) using the Exeter Universal stem.

INTRODUCTION. In theory, Finite Element Analysis (FEA) is an attractive method for elucidating the mechanics of modular implant junctions, including variations in materials, designs, and modes of loading. However, the credence of any computational model can only be established through validation using experimental data. In this study we examine the validity of such a simulation validated by comparing values of interface motion predicted using FEA with values measured during experimental simulation of stair-climbing. MATERIALS and METHODS. Two finite element models (FEM) of a modular implant assembly were created for use in this study, consisting of a 36mm CoCr femoral head attached to a TiAlV rod with a 14/12 trunnion. Two head materials were modelled: CoCr alloy (118,706 10-noded tetrahedral elements), and alumina ceramic (124,710 10-noded tetrahedral elements). The quasi-static coefficients of friction (µ. s. ) of the CoCr-TiAlV and Ceramic-TiAlV interfaces were calculated from uniaxial assembly (2000N) and dis-assembly experiments performed in a mechanical testing machine (Bionix, MTS). Interface displacements during taper assembly and disassembly were measured using digital image correlation (DIC; Dantec Dynamics). The assembly process was also simulated using the computational model with the friction coefficient set to µ. s. and solved using the Siemens Nastran NX 11.0 Solver. The frictional conditions were then varied iteratively to find the value of µ providing the closest estimate to the experimental value of head displacement during assembly. To validate the FEA model, the relative motion between the head and the trunnion was measured during dynamic loading simulating stair-climbing. Each modular junction was assembled in a drop tower apparatus and then cyclically loaded from 230–4300N at 1 Hz for a total of 2,000 cycles. The applied load was oriented at 25° to the trunnion axis in the frontal plane and 10° in the sagittal plane. The displacement of the head relative to the trunnion during cyclic loading was measured by a three-camera digital image correlation (DIC) system. The same loading conditions were simulated using the FEA model using the optimal value of µ derived from the initial head assembly trials. RESULTS. For both head materials, the predicted values of axial displacement of the head on the trunnion closely approximated the measured values derived from DIC measurements, with differences of −0.17% to +6.5%, respectively. Larger differences were calculated for individual components of motion for the stair climbing activity. However, the predicted magnitude of interface motion was still within 10% of the observed values, ranging from −7% to −5%. CONCLUSIONS. Our simulations closely approximated physical testing using complex loading, coming within 7% of the target values. By generating a validated computational model of a modular junctions with varying head materials, we will be able to simulate additional activities of daily living to determine micromotion and areas of peak pressure and contact stresses generated. For any figures or tables, please contact authors directly

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Local concentration of antibiotic at the site of infection is a major parameter for its efficiency. However, bone diffusion is poor leading either to their non-use (ex: gentamicin) or the use of high concentration (ex: vancomycin). Local administration could optimize their local concentration combined with lower side effects. We report the clinical experience and pharmacological results of an antibiotic loaded porous alumina used to replace infected bone in 4 patients.

Ceramic bearings have several desirable properties, such as resistance to wear, hardness, and biocompatibility, that favour it as an articulating surface in hip arthroplasty. However, ceramic fracture remains a concern. We have reviewed the contemporary literature, addressing the factors that can influence the incidence of ceramic bearing surface fracture.

Cite this article: Bone Joint J 2019;101-B:897–901.

Aims. Total ankle arthroplasty (TAA) has become the most reliable surgical solution for patients with end-stage arthritis of the ankle. Aseptic loosening of the talar component is the most common complication. A custom-made artificial talus can be used as the talar component in a combined TAA for patients with poor bone stock of the talus. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA. Patients and Methods. Ten patients (two men, eight women; ten ankles) treated using a combined TAA between 2009 and 2013 were matched for age, gender, and length of follow-up with 12 patients (one man, 11 women; 12 ankles) who underwent a standard TAA. All had end-stage arthritis of the ankle. The combined TAA features a tibial component of the TNK ankle (Kyocera, Kyoto, Japan) and an alumina ceramic artificial talus (Kyocera), designed using individualized CT data. The mean age at the time of surgery in the combined TAA and standard TAA groups was 71 years (. 61. to 82) and 75 years (62 to 82), respectively. The mean follow-up was 58 months (43 to 81) and 64 months (48 to 88), respectively. The outcome was assessed using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Ankle Osteoarthritis Scale (AOS), and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Results. The mean preoperative JSSF score of the combined TAA and standard TAA groups was 44 (. sd. 11) and 49 (. sd. 10), respectively. The mean postoperative JSSF scores were 89 (. sd. 6.1) and 72 (. sd. 15), respectively. The mean postoperative JSSF score of the combined TAA group was significantly higher (p = 0.0034). The mean preoperative AOS scores for pain and function in the combined TAA and standard TAA groups were 5.8 (. sd. 3.3) and 5.5 (. sd. 3.1), and 8.6 (. sd. 1.3), and 7.1 (. sd. 2.9), respectively. The mean postoperative AOS scores of pain and function were 2.5 (. sd. 2.5) and 2.2 (. sd. 1.9), and 2.5 (. sd. 3.3) and 3.4 (. sd. 2.9), respectively. There were no significant differences between the two groups in terms of postoperative AOS scores. The mean postoperative SAFE-Q scores were: for pain, 76 (. sd. 23) and 70 (. sd. 23); for physical function, 66 (. sd. 25) and 55 (. sd. 27); for social function, 73 (. sd. 35) and 62 (. sd. 34); for shoe-related, 73 (. sd. 19) and 65 (. sd. 26); and for general health, 78 (. sd. 28) and 67 (. sd. 29), respectively. There were no significant differences between the two groups in terms of postoperative SAFE-Q scores. Conclusion. Combined TAA resulted in better clinical results than standard TAA. Cite this article: Bone Joint J 2019;101-B:443–446

A pin-on-disc tribometer test with a rotating disc and a sector-wise loaded pin was used to determine friction coefficients for different material pairings. The four pin materials porcine cartilage, subchondral bone of the porcine cartilage, UHMWPE, vitamin E enhanced, crosslinked UHMWPE (VEPE) in combination with the three-disc materials zirconia toughened alumina ceramic (ZTA), CoCr, carbon-fibre-reinforced carbon (CrC) were tested. Stepwise loading was employed with the forces 10 N, 5 N, 2 N and 1 N. Test duration was 1 h. Diluted calf serum according ISO 14242-1 was used to determine the friction coefficients. The surface topography of all pins was examined using optical profilometry before and after the rotation tribometer tests. - No wear related modifications of the surface roughness parameters could be found. The coefficients of friction (COF) were lowest for the cartilage pins against all three-disc materials, with steady-state values between 0.01 and 0.02 for the highest applied load (10 N). Friction of subchondral bone yielded COF in the range 0.2 … 0.6, depending on the counterpart material. The two polyethylene materials behaved similar in this friction test with COF of about 0.1. The Ra roughness values of the different pins reflect the COF results: Ra of subchondral bone was one order of magnitude higher than Ra of the cartilage. This is in-line with the COF-values of bone being one order of magnitude higher than those of cartilage. These results will be discussed in view of the use of the disc materials as orthopaedic hemi-prostheses

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The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA).

Key Points:. Historically, 22.25, 26, 28, or 32 mm metal femoral heads were used in primary total hip arthroplasty, but innovations in materials now permit head sizes 36 mm or larger. Stability and wear of primary total hip arthroplasty are related to the diameter and material of the femoral head. Larger diameter femoral heads are associated with increased joint stability through increases in arc range of motion and excursion distance prior to dislocation. Fixation of the acetabular component may be related to the size of the femoral head, with increased frictional torque associated with large diameter heads and certain polyethylene. Linear wear of highly crosslinked polyethylenes seems unrelated to femoral head diameter, but larger heads have been reported to have higher volumetric wear. Mechanically assisted crevice corrosion at the connection between the modular femoral head and neck may be associated with the femoral head size and material. Cobalt chromium alloy, alumina ceramic composite, or oxidised zirconium femoral heads on highly crosslinked polyethylene are the most commonly used bearing surfaces, but each may have unique risks and benefits. Conclusions. At present, there is a wave of enthusiasm for the routine use of “large” (32, 36 mm, or larger) femoral heads with highly crosslinked polyethylene for the vast majority of patients having a primary THA. It may be reasonable to consider the “graduated femoral head-outer acetabular diameter system”, using 28 mm femoral heads with “smaller” acetabular components (<50 mm), 32 mm femoral heads with acetabular components 50 – 56 mm outer diameter, and 36 mm or larger femoral heads with acetabular components 58 mm or larger in diameter, to minimise both the risk of dislocation and the frictional torque. Although the linear wear of highly crosslinked polyethylene appears to be independent of head size, the reported increase in volumetric wear with large femoral heads and highly crosslinked polyethylene requires further study, and should temper the use of femoral heads 36 mm or larger in younger and more active patients. With its long and successful history, it is difficult to recommend the complete abandonment of the cobalt chromium alloy femoral head in all patients having a primary THA. Alumina ceramic or oxidised zirconium heads may be considered for younger, heavier, and more active patients, who seem to have the highest risk of trunnion corrosion. Surgeons and patients should be aware of the unique possible complications of these two newer femoral head materials

Despite its intrinsic ability to regenerate form and function after injury, bone tissue can be challenged by a multitude of pathological conditions. While innovative approaches have helped to unravel the cascades of bone healing, this knowledge has so far not improved the clinical outcomes of bone defect treatment. Recent findings have allowed us to gain in-depth knowledge about the physiological conditions and biological principles of bone regeneration. Now it is time to transfer the lessons learned from bone healing to the challenging scenarios in defects and employ innovative technologies to enable biomaterial-based strategies for bone defect healing. This review aims to provide an overview on endogenous cascades of bone material formation and how these are transferred to new perspectives in biomaterial-driven approaches in bone regeneration.

Cite this article: T. Winkler, F. A. Sass, G. N. Duda, K. Schmidt-Bleek. A review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering: The unsolved challenge. Bone Joint Res 2018;7:232–243. DOI: 10.1302/2046-3758.73.BJR-2017-0270.R1.

Since the universal failure of first generation smooth threaded cups in primary total hip arthroplasty (THA), the screw-in concept of cementless acetabular cup fixation has been largely abandoned. We hypothesised that grit-blasted titanium conical cement free threaded cup shows stable long-term fixation. 198 Alloclassic total hip arthroplasties were performed in 179 patients, mean age 66 years old (22–85). 193 hips were analyzed after a mean follow-up of 10 years (1–25 years). Results were excellent or good in 184 hips (95%). Postel-Merle d'Aubigne score increased from 10.3 (range 1 to 15) pre-operatively to 16.7 (12 to 18) points and 151 hips (78%) were pain free at last FU. Radiographic signs indicating successful cup osseointegration were noted in 92% of hips. Polyethylene wear > 0.1mm/year was observed in 6 hips (3%). The main cause of re-operation/revision surgery was recurrent dislocation (9/17cases, 53%). 2 threaded cups were revised for any reason and the revision per cent observed acetabular component years was 0.10 at 10 years average FU. 20 year-survival of the metal back was 98.8% (77.2–99.9%) and 100% (79.6–100%) for revision for any reason and revision for aseptic loosening, respectively. Despite minimum PE thickness of 6.5mm and use of alumina ceramic 28mm heads, conventional polyethylene liner wear was the weak link of the acetabular reconstruction;. This study shows excellent long-lasting bone anchorage through bone on-grown of grit-blasted titanium threaded cup. Despite universal outstanding longevity in the worldwide literature, CSF threaded cups were retrieved from the European market in March 2017 due to insufficient sales, indicating that evidence base medicine may not be the major criteria influencing surgeons' choice

Aims. Our aim in this study was to describe a continuing review of 11 total hip arthroplasties using 22.225 mm Alumina ceramic femoral heads on a Charnley flanged femoral component, articulating against a silane crosslinked polyethylene. Patients and Methods. Nine patients (11 THAs) were reviewed at a mean of 27.5 years (26 to 28) post-operatively. Outcome was assessed using the d’Aubigne and Postel, and Charnley scores and penetration was recorded on radiographs. In addition, the oxidation of a 29-year-old shelf-aged acetabular component was analysed. Results. The mean clinical outcome scores remained excellent at final follow-up. The mean total penetration remained 0.41 mm (0.40 to 0.41). There was no radiographic evidence of acetabular or femoral loosening or osteolysis. There was negligible oxidation in the shelf-aged sample despite gamma irradiation and storage in air. Conclusion. These results highlight the long-term stability and durability of this type of crosslinked, antioxidant containing polyethylene when used in combination with a small diameter alumina ceramic femoral head. Cite this article: Bone Joint J 2017;99-B:1286–9

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Ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used, but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man.

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To determine the effect of a change in design of a cementless ceramic acetabular component in fixation and clinical outcome after total hip arthroplasty

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We conducted a prospective study of a delta ceramic total hip arthroplasty (THA) to determine the rate of ceramic fracture, to characterise post-operative noise, and to evaluate the mid-term results and survivorship.