The Thompson hemiarthroplasty is a common treatment option for acute neck of femur fractures in the elderly population. Our department noted a significant number of patients returning with thigh pain, radiographic loosening and femoral osteolysis following cemented implantation of the titanium alloy version of the Thompson hemiarthroplasty. We are not aware of any previous reports documenting complications specific to the titanium Thompson implant and a retrospective cohort study was therefore initiated following clinical governance approval.

366 titanium alloy Thompson prostheses were implanted for hip fracture treatment between 2017 and 2020. As of February 2023, 6 of these have been revised at our hospital. 5 were revised for symptomatic femoral osteolysis and 1 presented with an acute periprosthetic fracture. All revised cases were determined to be aseptic. 32 living patients were excluded from recall on compassionate grounds due to permanent nursing home residence. 47 living patients were identified of which 33 attended for xray. 28 deceased and/or nursing home resident patients who had pelvis x-rays in the previous 12 months were also included in the analysis. Including the 6 index hips already revised, a total of 61 hip xrays were analysed, of which 19 hips (31.1%) showed radiographic evidence of femoral osteolysis or loosening.

We conclude that there is a concerning incidence of femoral osteolysis and implant loosening associated with the titanium Thompson implant. We have discontinued use of the implant and reported our experience to the MHRA. We encourage other Scottish Health-Boards who use this implant to consider enhanced follow-up.

Osteoporosis following ovariectomy has been suggested to modulate bone response to polyethylene wear debris. In this work, we evaluate the influence of estrogen deficiency on experimental particle-induced osteolysis. Polyethylene (PE) particles were implanted onto the calvaria of wild-type (WT), sham-ovariectomized (OVX), OVX mice and OVX mice supplemented with estrogen (OVX+E2) (12 mice per group). Sham-implanted mice served as internal controls. After 14 days, seven skulls per group were analyzed with a high-resolution micro-computed tomography (CT) and by histomorphometry, and for tartrate-specific alkaline phosphatase. Five calvariae per group were cultured for the assay of IL-1, IL-6, TNF- and RANKL secretion using quantitative ELISA. The expression of RANKL and OPG mRNA were evaluated using real-time PCR. As assessed by CT and by histomorphometry, PE particles induced an extensive bone resorption and an intense inflammatory reaction in WT, sham-OVX and OVX+E2 mice. In OVX mice group, these features appeared considerably attenuated. In WT, sham-OVX and OVX+E2 mice, PE particles induced an increase in serum IL-6, in TNF-and RANKL local concentrations, and resulted in a two-fold increase in RANKL/OPG mRNA ratio. Conversely, these parameters remained unchanged in OVX mice after PE implantation. The combination of two well-known bone resorptive mechanisms ultimately attenuated osteolytic response, suggesting a protective effect of estrogen deficiency on particle-induced osteolysis. This paradoxical phenomenon was associated with a downregulation of pro-resorptive cytokines. It is hypothesized that excessive inflammatory response was controlled, illustrated by the absence of increase of serum IL-6 in OVX mice after PE implantation.

Introduction

Large wear rate reductions have been shown for crosslinked PE in simulators and short- to mid-term clinical wear studies. However, concerns persist about long-term in-vivo oxidation (especially with annealed PE), late accelerating wear and the possibly higher osteolytic potential of crosslinked PE particle debris. This is the first long-term study comparing conventional to crosslinked PE investigating whether the wear reduction is maintained in the long-term and if reduced osteolysis becomes evident.

Aims. Will Hydroxyapatite hip (HA) arthroplasty associated with ceramic bearings produce uncomplicated function in younger, active patients’ The incidence of aseptic loosening, dislocation and broken implants has been particularly investigated. Debris disease from plastic debris contributes to aseptic loosening. Hard-Hard bearings should obviate this problem. Metal-metal will release ions which might be deleterious. Experience with metal-metal resurfacing has high lighted problems including pseudo-tumours. Ceramic bearings may fracture but otherwise appear free of complications. Methods. This is a study extending over 19 years of 626 HA hip arthroplasties with ceramic bearings. Annual review using Harris Hip Score to assess pain and function and X-rays to check osseointegration has been performed. Alumina ceramic was inserted in 467 hips. The newer Zirconia Toughened Alumina (ZTA) has been inserted in 169 hips. There are 118 hips still under review at 10 or more years. Results. Aseptic loosening is unusual (one stem, two acetabulae (3 of 1252 components, 0.24%) Failure from mal-orientation with repeated dislocation occurred in six hips (0.96%). Three alumina heads (0.48%) and two alumina liners (0.32%) broke. There has been no failure of ZTA ceramic. No patients have thigh pain. Osteolysis and debris disease have not arisen. Harris Hip Scores show 91.2% scoring over 90 or 100. Lower scores mostly relate to other joint and medical problems. Conclusions. Assessments confirm that patients remain well. Aseptic loosening of HA hips is rare at 0.24%. Failure from broken alumina components is unusual. Alumina has now been superseded by ZTA for implantation. Ceramic on ceramic is a reliable selection for bearing surfaces in patients of any age and either sex

Osteolysis induced by UHMWPE debris has historically been one of the major causes of long term failure of TJR. An increase in concentration of polyethylene particles in the peri-prostheic tissue has been linked to an increased incidence of osteolysis. The dual mobility hip bearing concept mates a femoral head into a polyethylene liner which has an unconstrained articulation into a metal shell. The wear mechanism of the dual mobility hip bearing is distinct from a constrained single articulation design, which may result in a difference in wear debris particles. The aim of this study is to evaluate wear debris generated from a dual mobility hip and compare it to a conventional single articulation design when both are manufactured from sequentially crosslinked and annealed polyethylene. The dual mobility hip (Restoration ADM) incorporated a 28mm CoCr femoral head into a polyethylene liner that articulates against a metal shell (48mm ID). The conventional hip (Trident®) mated a 28mm CoCr femoral head against a polyethylene liner. The polyethylene for all liners was sequentially crosslinked and annealed (X3). A hip joint simulator was used for testing at a rate of 1 Hz with cyclic Paul curve physiologic loading. A serum sample from each testing group was collected. Serum samples were protein digested following the published process by Scott et al. The digested serum was then filtered through a series of polycarbonate filter papers of decreasing size and sputter coated with gold for analysis using SEM. Image fields were randomized and wear debris was compared in terms of its length, width, aspect ration, and equivalent circular diameter (ECD). A total of 149 conventional hip particles and 114 dual mobility hip particles were imaged. Results show a majority of particles are of spherical nature and images do not indicate the presence of fibrillar or larger elongated polyethylene debris. Particle length between designs is not statistically different, while all other comparisons show statistical significance (p<0.05). It is hypothesized that the dual mobility hip system reduces the total amount of cross-shear motion on any one articulation, which aids in the reduction in wear. This design feature may be responsible for the slight difference in morphology of dual mobility wear debris when compared to the constrained hip design. The length of the particles was similar, simply indicating a different shape rather than a marked reduction in overall size. The debris generated is this study was from highly crosslinked polyethylene in two different designs, which produced a very significant decrease in quantity of particles when compared to the quantity of debris from conventional polyethylene. The wear debris was of similar length in both designs and so we do not expect any difference in biological response to debris from either device. The dual mobility design has also shown no effect of cup abduction angle on wear demonstrating forgiveness to implant positioning. This advantage, combined with the low wear rate and similar length wear particles, should lead to good clinical performance of dual mobility cups with sequentially irradiated and annealed polyethylene