Aims

The purpose of this study was to directly compare the Modular Dual Mobility (MDM) Mobile Bearing Hip System (Stryker, USA) and large femoral heads (LFHs) in revision total hip arthroplasties (THAs) at mid-term follow-up, with specific emphasis on survival free of re-revision for dislocation, any re-revision, dislocation, and the risk of metal-related complications.

Objectives. Unicompartmental knee replacement (UKR) is a conservative option for degenerative disease, with mobile (Oxford UKR) and fixed bearing (Physica ZUK) the most commonly used devices. The primary reasons for revising UKRs include disease progression (36.9%), loosening (31.7%), and pain (7.5%). Loosening typically occurs due to osteolysis caused by wear particles from the polyethylene (PE) inserts. There is limited published literature which has quantified volumetric material loss from the PE inserts of cemented fixed-bearing UKRs. This study aimed to quantify bearing wear and backside deformation of these PE components. Design and Methods. At our national retrieval centre, we measured changes volumetric bearing wear and backside deformation of 31 explanted fixed-bearing Physica ZUK UKR PE inserts using a peer-reviewed methodology based on coordinate measuring machine analysis. These explants had been revised for any indication [Females (19) and Males (12)]. The location of the wear scars was identified and mapped. We compared the volumetric wear from the bearing surface with contemporary total knee replacement (TKR) inserts. Results. The median (IQR) total volumetric wear of the UKR PEs [96(50-152) mm. 3. ] was significantly higher (p<0.001) than contemporary TKR PEs [40 (24-83) mm. 3. ]. The median (IQR) total volumetric wear of the PEs in males [148(122-200) mm. 3. ] was significantly higher(p=0.016) than in females [56(61-119) mm. 3. ]. The wear scars were situated in the anterior third in 61% of cases, with 26% located posteriorly. Examination of the PE backside surfaces exhibited damage in the area directly inferior to the bearing surface wear scar in the majority of cases. Conclusion. In conclusion, this study highlights significant PE wear of Physica ZUK UKR inserts, with higher wear rates compared to contemporary TKR inserts, particularly in males

Objectives. We identified an unusual pattern of backside deformation on polyethylene (PE) inserts of contemporary total knee replacements (TKRs). The PE backside's margins were inferiorly deformed in TKRs with NexGen central-locking trays. This backside deformation was significantly associated with tray debonding. Furthermore, recent studies have shown high rate of tray debonding in PS NexGen TKRs. Subsequently, a field safety notice was issued regarding the performance of this particular device combination and the Option tray has been withdrawn from use. Therefore, we hypothesised that the backside deformation of PS inserts may be greater than that of CR inserts. Design and Methods. At our national implant retrieval centre, we used peer-reviewed techniques to analyse changes in the bearing wear rate and backside surface deformation of NexGen PE inserts using coordinate measuring machines [N=84 (CR-43 and PS-41) TKRs with non-augmented-trays]. Multiple regression was used to determine which variable had the greatest influence on backside deformation. The amount of cement cover on trays was quantified as a %of the total surface using Image-J software. Results. The median (IQR) bearing wear rate of the PS PEs [14(8-22) mm. 3. /year] was not significantly different(p=0.154) to that of the CR PEs [18(8-27)mm. 3. /year]. The median (IQR) backside deformation of the PS inserts [294(239-361) µm] was significantly greater (p<0.001) than that of the CR inserts [212(158-258)µm]. Multiple regression modelling showed that duration in-vivo (p=0.037), central-clearance between insert and tray (p<0.001) and constraint (p=0.003) were significantly associated with PE backside-deformation. 38(93%) PS and 31(72%) of CR trays exhibited ≤10% of cement cover. Non-contacting profilometry and microscopy revealed marked pitting and abrasive changes to the superior surface of the tray. Conclusion. This explant study showed the PE backside deformation was significantly higher in PS than in CR inserts and this may be one explanation for the unsatisfactory clinical performance reported with this device combination

Aims

Highly cross-linked polyethylene (HXLPE) greatly reduces wear in total hip arthroplasty, compared to conventional polyethylene (CPE). Cross-linking is commonly achieved by irradiation. This study aimed to compare the degree of cross-linking and in vitro wear rates across a cohort of retrieved and unused polyethylene cups/liners from various brands.

Aim. Diagnosis of prosthetic joint infection are often complicated by the presence of biofilm, which hampers bacteria dislodging from the implants, thus affecting sensitivity of cultures. In the last 20 years several studies have evidenced the usefulness of implant sonication to improve microbial recovery from biofilm formed on inert substrates. More recently, treatment of prosthetic joints and tissues with Dithiothreitol, a sulphur compound already used in routine diagnostic workflow for fluidification of respiratory samples, has proved to be not inferior to sonication in microbiological diagnosis of prosthetic joint infections. This study aimed to evaluate if the combination of the two treatments could further improve microbial retrieval from biofilm in an in vitro model. Method. Three isolates of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus lugdunensis, Eschericha coli and Pseudomonas aeruginosa responsible of prosthetic joint infections were used. They were grown onto 3 titanium discs (20 mm diameter) and incubated in 3 sterile plastic containers with 15 mL of Triptyc Soy Broth. After overnight incubation, not adhered cells were removed and fresh broth was added to each sample. After 48 hours incubation, the exausted broth was removed and one sample was used for sonication, one for treatment with 0,1% (v:v) Dithiothreitol and one treated with Dithiothreitol followed by sonication. Treated fluids were plated on Muller Hinton Agar plates for colony count. One-way ANOVA analysis was performed to evidence statistical differences between treatments. Results. Similar colony counts were observed for the 3 treatments: 10.1± 0.77 log CFU/mL for Dithiothreitol, 10.0 ± 0.75 for sonication and 10.1 ±0.73 for dithiothreitol + sonication. No statistical differences between the 3 treatments were evidenced by ANOVA analysis. Conclusions. Results seems to confirm that treatment with dithiothreitol is equivalent to sonication in recovering bacteria from biofilm grown on inert surface. Combining dithiotreitol treatment with sonication does not significantly improve bacterial recovery in respect to each treatment alone

Aims

In 2015, we published the results of our ceramic-on-metal (CoM) total hip arthroplasties (THAs) performed between October 2007 and July 2009 with a mean follow-up of 34 months (23 to 45) and a revision rate of 3.1%. The aim of this paper is to present the longer-term outcomes.

Aims

This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision.

Aims

This study aimed to demonstrate the promoting effect of elastic fixation on fracture, and further explore its mechanism at the gene and protein expression levels.

Aims

The optimum type of antibiotics and their administration route for treating Gram-negative (GN) periprosthetic joint infection (PJI) remain controversial. This study aimed to determine the GN bacterial species and antibacterial resistance rates related to clinical GN-PJI, and to determine the efficacy and safety of intra-articular (IA) antibiotic injection after one-stage revision in a GN pathogen-induced PJI rat model of total knee arthroplasty.

Aims

Vascular compromise due to arterial injury is a rare but serious complication of a proximal humeral fracture. The aims of this study were to report its incidence in a large urban population, and to identify clinical and radiological factors which are associated with this complication. We also evaluated the results of the use of our protocol for the management of these injuries.

Aims

This study aimed to determine the expression and clinical significance of a cartilage protein, cartilage oligomeric matrix protein (COMP), in knee osteoarthritis (OA) patients.

Aims

Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of total knee arthroplasty (TKA). Using radiostereometric analysis (RSA) with tantalum beads in the PE inlay, we evaluated PE micromotion and its relationship to PE wear.

Aims

The aim of this study was to determine the fracture haematoma (fxH) proteome after multiple trauma using label-free proteomics, comparing two different fracture treatment strategies.

Aims. Oxidized zirconium (OxZi) and highly cross-linked polyethylene (HXLPE) were developed to minimize wear and risk of osteolysis in total hip arthroplasty (THA). However, retrieval studies have shown that scratched femoral heads may lead to runaway wear, and few reports of long-term results have been published. The purpose of this investigation is to report minimum ten-year wear rates and clinical outcomes of THA with OxZi femoral heads on HXLPE, and to compare them with a retrospective control group of cobalt chrome (CoCr) or ceramic heads on HXLPE. Methods. From 2003 to 2006, 108 THAs were performed on 96 patients using an OxZi head with a HXLPE liner with minimum ten-year follow-up. Harris Hip Scores (HHS) were collected preoperatively and at the most recent follow-up (mean 13.3 years). Linear and volumetric liner wear was measured on radiographs of 85 hips with a minimum ten-year follow-up (mean 14.5 years). This was compared to a retrospective control group of 45 THAs using ceramic or CoCr heads from October 1999 to February 2005, with a minimum of ten years’ follow-up. Results. Average HHS improved from 50.8 to 91.9 and 51.0 to 89.8 in the OxZi group and control group, respectively (p = 0.644), with no osteolysis in either group. Linear and volumetric wear rates in the OxZi group averaged 0.03 mm/year and 3.46 mm. 3. /year, respectively. There was no statistically significant difference in HHS scores, nor in linear or volumetric wear rate between the groups, and no revision for any indication. Conclusion. The radiological and clinical outcomes, and survivorship of THA with OxZi femoral heads and HXLPE liners, were excellent, and comparable to CoCr or ceramic heads at minimum ten-year follow-up. Wear rates are below what would be expected for development of osteolysis. OxZi-HXLPE is a durable bearing couple with excellent long-term outcomes. Cite this article: Bone Joint J 2024;106-B(3 Supple A):38–43

Aims

In metal-on-polyethylene (MoP) total hip arthroplasty (THA), large metal femoral heads have been used to increase stability and reduce the risk of dislocation. The increased size of the femoral head can, however, lead to increased taper corrosion, with the release of metal ions and adverse reactions. The aim of this study was to investigate the relationship between the size of the femoral head and the levels of metal ions in the blood in these patients.

The February 2024 Knee Roundup³⁶⁰ looks at: Do patients with hypoallergenic total knee arthroplasty implants for metal allergy do worse? An analysis of healthcare utilizations and patient-reported outcome measures; Defining a successful total knee arthroplasty; Incidence, microbiological studies, and factors associated with periprosthetic joint infection after total knee arthroplasty; A modified Delphi consensus statement on patellar instability; Cause for concern? Significant cement coverage in retrieved metaphyseal cones after revision total knee arthroplasty; Prevalence of post-traumatic osteoarthritis after anterior cruciate ligament injury remains high despite advances in surgical techniques; Cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy for traumatic meniscal tears in patients aged under 45 years.

Displaced fractures of the distal radius in children are usually reduced under sedation or general anaesthesia to restore anatomical alignment before the limb is immobilized. However, there is growing evidence of the ability of the distal radius to remodel rapidly, raising doubts over the benefit to these children of restoring alignment. There is now clinical equipoise concerning whether or not young children with displaced distal radial fractures benefit from reduction, as they have the greatest ability to remodel. The Children’s Radius Acute Fracture Fixation Trial (CRAFFT), funded by the National Institute for Health and Care Research, aims to definitively answer this question and determine how best to manage severely displaced distal radial fractures in children aged up to ten years.

Cite this article: Bone Joint J 2024;106-B(1):16–18.

Aims

Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration.

The purpose of this study was to investigate the effectiveness of casting in achieving acceptable radiological parameters for unstable ankle injuries. This retrospective observational cohort study was conducted involving the retrieval of X-rays of all ankles taken over a 2 year period in an urban setting to investigate the radiological outcomes of cast management for unstable ankle fractures using four acceptable parameters measured on a single X- ray at union. The Picture Archiving and Communication System (PACS) was used, the X-rays were measured by a single observer. From the 1st of January 2020 to the 31st of December 2021, a total of 1043 ankle fractures were treated at the three hospitals with a male to female ratio of 1:1.7. Of the 628 unstable ankle injuries, 19% of patients were lost to follow up. 190 were managed conservatively with casts, requiring an average of 4 manipulations, with a malunion rate of 23.2%. Unstable ankle injuries that were treated surgically from the outset and those who failed conservative management and subsequently converted to surgery had a malunion rate of 8.1% and 11.0% respectively. Unstable ankle fractures pose a challenge with a high rate of radiological malunion, regardless of the treatment Casting surgery from the outset or converted to surgery, with rates of 23% and 8% and 11% respectively. In this multivariate analysis we found that conservative management was the only factor influencing the incidence of malunion, age, sex and type of fracture did not have a scientific significant influence