We undertook a multicentre, prospective study of a series of 112 unstable trochanteric fractures in order to evaluate if internal fixation with a sliding screw device combined with augmentation using a calcium
Large acetabular bone defects encountered in revision total hip arthroplasty (THA) are challenging to restore. Metal constructs for structural support are combined with bone graft materials for restoration. Autograft is restricted due to limited volume, and allogenic grafts have downsides including cost, availability, and operative processing. Bone graft substitutes (BGS) are an attractive alternative if they can demonstrate positive remodelling. One potential product is a biphasic injectable mixture (Cerament) that combines a fast-resorbing material (calcium sulphate) with the highly osteoconductive material hydroxyapatite. This study reviews the application of this biomaterial in large acetabular defects. We performed a retrospective review at a single institution of patients undergoing revision THA by a single surgeon. We identified 49 consecutive patients with large acetabular defects where the biphasic BGS was applied, with no other products added to the BGS. After placement of metallic acetabular implants, the BGS was injected into the remaining bone defects surrounding the new implants. Patients were followed and monitored for functional outcome scores, implant fixation, radiological graft site remodelling, and revision failures.Aims
Methods
A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient’s quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach. A group of eight patients revised due to a PJI with a previous lateral approach was compared with a group of 21 revised THAs without infection, performed using the same approach. The primary variables of the study were the fibril diameter, as seen in transmission electron microscopy (TEM), and the total degeneration score (TDS), as seen under the light microscope. An analysis of bacteriology, classification of infection, and antibiotic treatment was also performed.Aims
Methods
The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group). The study included 36 patients with T-HA stems and 30 with N-HA stems. Dual-energy X-ray absorptiometry was used to measure the change in periprosthetic BMD, one and two years postoperatively. The 3D contact between the stem and femoral cortical bone was evaluated using a density-mapping system, and clinical assessment, including patient-reported outcome measurements, was recorded.Aims
Methods
BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems. A total of 53 patients were randomized to be treated using Bi-Metric cementless femoral stems with either only a porous titanium plasma-sprayed coating (P group) or a porous titanium plasma-sprayed coating with an additional BoneMaster coating (PBM group). The patients were examined with radiostereometry until five years after surgery.Aims
Methods
This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads. In all, six 28 mm and six 36 mm titanium stem-cobalt chrome head pairs with polyethylene sockets were tested in a novel instrumented hip simulator. Samples were tested using simulated gait data with incremental increasing loads to determine corrosion onset load and electrochemical activity. Half of each head size group were then cycled with simulated gait and the other half with gait compression only. Damage was measured by area and maximum linear wear depth.Aims
Methods
This combined clinical and in vitro study aimed to determine the incidence of liner malseating in modular dual mobility (MDM) constructs in primary total hip arthroplasties (THAs) from a large volume arthroplasty centre, and determine whether malseating increases the potential for fretting and corrosion at the modular metal interface in malseated MDM constructs using a simulated corrosion chamber. For the clinical arm of the study, observers independently reviewed postoperative radiographs of 551 primary THAs using MDM constructs from a single manufacturer over a three-year period, to identify the incidence of MDM liner-shell malseating. Multivariable logistic regression analysis was performed to identify risk factors including age, sex, body mass index (BMI), cup design, cup size, and the MDM case volume of the surgeon. For the in vitro arm, six pristine MDM implants with cobalt-chrome liners were tested in a simulated corrosion chamber. Three were well-seated and three were malseated with 6° of canting. The liner-shell couples underwent cyclic loading of increasing magnitudes. Fretting current was measured throughout testing and the onset of fretting load was determined by analyzing the increase in average current.Aims
Methods
Fixation of osteoporotic proximal humerus fractures remains challenging even with state-of-the-art locking plates. Despite the demonstrated biomechanical benefit of screw tip augmentation with bone cement, the clinical findings have remained unclear, potentially as the optimal augmentation combinations are unknown. The aim of this study was to systematically evaluate the biomechanical benefits of the augmentation options in a humeral locking plate using finite element analysis (FEA). A total of 64 cement augmentation configurations were analyzed using six screws of a locking plate to virtually fix unstable three-part fractures in 24 low-density proximal humerus models under three physiological loading cases (4,608 simulations). The biomechanical benefit of augmentation was evaluated through an established FEA methodology using the average peri-screw bone strain as a validated predictor of cyclic cut-out failure.Aims
Methods
Prosthetic joint infection (PJI) and aseptic loosening in total hip arthroplasty (THA) can present with pain and osteolysis. The Musculoskeletal Infection Society (MSIS) has provided criteria for the diagnosis of PJI. The aim of our study was to analyze the utility of F18-fluorodeoxyglucose (FDG) positron emission tomography (PET) CT scan in the preoperative diagnosis of septic loosening in THA, based on the current MSIS definition of prosthetic joint infection. A total of 130 painful unilateral cemented THAs with a mean follow-up of 5.17 years (Aims
Patients and Methods
The aim of this study was to estimate the 90-day risk of revision for periprosthetic femoral fracture associated with design features of cementless femoral stems, and to investigate the effect of a collar on this risk using a biomechanical A total of 337 647 primary total hip arthroplasties (THAs) from the United Kingdom National Joint Registry (NJR) were included in a multivariable survival and regression analysis to identify the adjusted hazard of revision for periprosthetic fracture following primary THA using a cementless stem. The effect of a collar in cementless THA on this risk was evaluated in an Aims
Materials and Methods
Custom flange acetabular components (CFACs) are a patient-specific option for addressing large acetabular defects at revision total hip arthroplasty (THA), but patient and implant characteristics that affect survivorship remain unknown. This study aimed to identify patient and design factors related to survivorship. A retrospective review of 91 patients who underwent revision THA using 96 CFACs was undertaken, comparing features between radiologically failed and successful cases. Patient characteristics (demographic, clinical, and radiological) and implant features (design characteristics and intraoperative features) were collected. There were 74 women and 22 men; their mean age was 62 years (31 to 85). The mean follow-up was 24.9 months (Aims
Patients and Methods
We investigated the reliability of the cobalt-chromium (CoCr) synovial joint fluid ratio (JFR) in identifying the presence of a severe aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) response and/or suboptimal taper performance (SOTP) following metal-on-metal (MoM) hip arthroplasty. We then examined the possibility that the CoCr JFR may influence the serum partitioning of Co and Cr. For part A, we included all revision surgeries carried out at our unit with the relevant data, including volumetric wear analysis, joint fluid (JF) Co and Cr concentrations, and ALVAL grade (n = 315). Receiver operating characteristic curves were constructed to assess the reliability of the CoCr JFR in identifying severe ALVAL and/or SOTP. For part B, we included only patients with unilateral prostheses who had given matched serum and whole blood samples for Co and Cr analysis (n = 155). Multiple regression was used to examine the influence of JF concentrations on the serum partitioning of Co and Cr in the blood.Objectives
Methods
A common situation presenting to the orthopaedic
surgeon today is a worn acetabular liner with substantial acetabular
and pelvic osteolysis. The surgeon has many options for dealing
with osteolytic defects. These include allograft, calcium based
substitutes, demineralised bone matrix, or combinations of these
options with or without addition of platelet rich plasma. To date
there are no clinical studies to determine the efficacy of using
bone-stimulating materials in osteolytic defects at the time of
revision surgery and there are surprisingly few studies demonstrating
the clinical efficacy of these treatment options. Even when radiographs
appear to demonstrate incorporation of graft material CT studies
have shown that incorporation is incomplete. The surgeon, in choosing
a graft material for a surgical procedure must take into account
the efficacy, safety, cost and convenience of that material. Cite this article:
Tantalum (Ta) trabecular metal components are increasingly used
to reconstruct major bone defects in revision arthroplasty surgery.
It is known that some metals such as silver have antibacterial properties.
Recent reports have raised the question regarding whether Ta components
are protective against infection in revision surgery. This laboratory
study aimed to establish whether Ta has intrinsic antibacterial
properties against planktonic bacteria, or the ability to inhibit
biofilm formation. Equal-sized pieces of Ta and titanium (Ti) acetabular components
were sterilised and incubated with a low dose inoculum of either Aims
Materials and Methods
This review summarises the technique of impaction
grafting with mesh augmentation for the treatment of uncontained
acetabular defects in revision hip arthroplasty. The ideal acetabular revision should restore bone stock, use
a small socket in the near-anatomic position, and provide durable
fixation. Impaction bone grafting, which has been in use for over
40 years, offers the ability to achieve these goals in uncontained
defects. The precepts of modern, revision impaction grafting are
that the segmental or cavitary defects must be supported with a
mesh; the contained cavity is filled with vigorously impacted morselised
fresh-frozen allograft; and finally, acrylic cement is used to stabilise
the graft and provide rigid, long-lasting fixation of the revised
acetabular component. Favourable results have been published with this technique. While
having its limitations, it is a viable option to address large acetabular
defects in revision arthroplasty. Cite this article:
The primary purpose of this meta-analysis was to determine whether statin usage could reduce the risk of glucocorticoid-related osteonecrosis in animal models. A systematic literature search up to May 2015 was carried out using the PubMed, Ovid, EBM reviews, ISI Web of Science, EBSCO, CBM, CNKI databases with the term and boolean operators: statins and osteonecrosis in all fields. Risk ratio (RR), as the risk estimate of specific outcome, was calculated along with 95% confidence intervals (CI). The methodological quality of individual studies was assessed using a quantitative tool based on the updated Stroke Therapy Academic Industry Roundtable (STAIR) recommendations.Objectives
Methods
This study aimed to characterise and qualitatively grade the severity of the corrosion particles released into the hip joint following taper corrosion. The 26 cases examined were CoC/ABG Modular (n = 13) and ASR/SROM (n = 13). Blood serum metal ion levels were collected before and after revision surgery. The haematoxylin and eosin tissue sections were graded on the presence of fibrin exudates, necrosis, inflammatory cells and corrosion products. The corrosion products were identified based on visible observation and graded on abundance. Two independent observers blinded to the clinical patient findings scored all cases. Elemental analysis was performed on corrosion products within tissue sections. X-Ray diffraction was used to identify crystalline structures present in taper debris.Objectives
Methods
Four uncemented Symax hip stems were extracted at three weeks and nine, 13 and 32 months, respectively, for reasons other than loosening. The reasons for implant removal were infection in two cases, recurrent dislocation in one and acetabular fracture in one. They were analysed to assess the effect and behaviour of an electrochemically deposited, completely resorbable biomimetic BONIT-hydroxyapatite (HA) coating (proximal part) and a DOTIZE surface treatment (distal part) using qualitative histology, quantitative histomorphometry and scanning electron microscopy (SEM). Early and direct bone-implant bonding with signs of active remodelling of bone and the HA coating were demonstrated by histology and SEM. No loose BONIT-HA particles or delamination of the coating were observed, and there was no inflammation or fibrous interposition at the interface. Histomorphometry showed bone-implant contact varying between 26.5% at three weeks and 83.5% at 13 months at the HA-coated implant surface. The bone density in the area of investigation was between 24.6% at three weeks and 41.1% at 32 months. The DOTIZE surface treatment of the distal part of the stem completely prevented tissue and bone apposition in all cases, thereby optimising proximal stress transfer. The overall features of this implant, in terms of geometry and surface texture, suggest a mechanically stable design with a highly active biomimetic coating, resulting in rapid and extensive osseo-integration, exclusively in the metaphyseal part of the stem. Early remodelling of the HA coating does not seem to have a detrimental effect on short-term bone-implant coupling. There were no adverse effects identified from either the BONIT-HA coating or the DOTIZE surface treatment.
The increasing need for total hip replacement
(THR) in an ageing population will inevitably generate a larger number
of revision procedures. The difficulties encountered in dealing
with the bone deficient acetabulum are amongst the greatest challenges
in hip surgery. The failed acetabular component requires reconstruction
to restore the hip centre and improve joint biomechanics. Impaction
bone grafting is successful in achieving acetabular reconstruction
using both cemented and cementless techniques. Bone graft incorporation
restores bone stock whilst providing good component stability. We
provide a summary of the evidence and current literature regarding impaction
bone grafting using both cemented and cementless techniques in revision
THR. Cite this article:
We report a case of a male patient presenting
with bilateral painful but apparently well-positioned and -fixed
large-diameter metal-on-metal hip replacements four years post-operatively.
Multiple imaging modes revealed a thick-walled, cystic expansile
mass in communication with the hip joint (a pseudotumour). Implant
retrieval analysis and tissue culture eliminated high bearing wear
or infection as causes for the soft-tissue reaction, but noted marked corrosion
of the modular neck taper adaptor and corrosion products in the
tissues. Therefore, we believe corrosion products from the taper
caused by mismatch of the implant components led to pseudotumour
formation requiring revision.
