Aims

To review the evidence and reach consensus on recommendations for follow-up after total hip and knee arthroplasty.

Aims

The aim of this study was to conduct a cross-sectional, observational cohort study of patients presenting for revision of a total hip, or total or unicompartmental knee arthroplasty, to understand current routes to revision surgery and explore differences in symptoms, healthcare use, reason for revision, and the revision surgery (surgical time, components, length of stay) between patients having regular follow-up and those without.

Aims

This study aimed to develop a virtual clinic for the purpose of reducing face-to-face orthopaedic consultations.

Aims

This study aimed to evaluate implant survival of reverse hybrid total hip arthroplasty (THA) at medium-term follow-up.

Aims

Increasing demand for total hip and knee arthroplasty (THA/TKA) and associated follow-up has placed huge demands on orthopaedic services. Feasible follow-up mechanisms are therefore essential.

The results of hip and knee replacement surgery are generally regarded as positive for patients. Nonetheless, they are both major operations and have recognised complications. We present a review of relevant claims made to the National Health Service Litigation Authority. Between 1995 and 2010 there were 1004 claims to a value of £41.5 million following hip replacement surgery and 523 claims to a value of £21 million for knee replacement. The most common complaint after hip surgery was related to residual neurological deficit, whereas after knee replacement it was related to infection. Vascular complications resulted in the highest costs per case in each group.

Although there has been a large increase in the number of operations performed, there has not been a corresponding relative increase in litigation. The reasons for litigation have remained largely unchanged over time after hip replacement. In the case of knee replacement, although there has been a reduction in claims for infection, there has been an increase in claims for technical errors. There has also been a rise in claims for non-specified dissatisfaction. This information is of value to surgeons and can be used to minimise the potential mismatch between patient expectation, informed consent and outcome.

Cite this article: Bone Joint J 2013;95-B:122–6.

Nanometre-sized particles of ultra-high molecular weight polyethylene have been identified in the lubricants retrieved from hip simulators. Tissue samples were taken from seven failed Charnley total hip replacements, digested using strong alkali and analysed using high-resolution field emission gun-scanning electron microscopy to determine whether nanometre-sized particles of polyethylene debris were generated in vivo. A randomised method of analysis was used to quantify and characterise all the polyethylene particles isolated.

We isolated nanometre-sized particles from the retrieved tissue samples. The smallest identified was 30 nm and the majority were in the 0.1 μm to 0.99 μm size range. Particles in the 1.0 μm to 9.99 μm size range represented the highest proportion of the wear volume of the tissue samples, with 35% to 98% of the total wear volume comprised of particles of this size. The number of nanometre-sized particles isolated from the tissues accounted for only a small proportion of the total wear volume. Further work is required to assess the biological response to nanometre-sized polyethylene particles.

The Wroblewski golf ball acetabular cup was introduced by surgeons using the trochanteric osteotomy approach for revision total hip replacement (THR) in order to reduce the rate of dislocation. We have routinely used the Ogee long posterior wall (Ogee LPW) and the Wroblewski angle bore cups in THR. Although the new Wroblewski golf ball cup performed well there was a significant early rate of dislocation of 20%. Our rate of dislocation over a period of ten years using the Ogee LPW and Wroblewski angle bore cups had been 0.52%. We present our findings and an investigation as to why the new cup has such a high rate of dislocation when used with the posterior approach. We show that a relatively small change in the design of the acetabular component resulted in significant adverse clinical results.

Proponents of the biological theory of aseptic loosening have in recent years tended to concentrate on the production and distribution of particulate ultra-high-molecular-weight polyethylene (UHMWPE) debris around the potential joint space. However, mechanical loading of cemented implants with the differing elastic moduli of metal stems, polymethylmethacrylate (PMMA) cement and bone can result in relative micromotion, implying the potential for production of metal and PMMA particles from the stem-cement interface by fretting wear.

In order to investigate the production and biological reactivity of debris from this interface, PMMA and metal particulate debris was produced by sliding wear of PMMA pins containing barium sulphate and zirconium dioxide against a Vaquasheened stainless steel counterface. This debris was characterised by SEM, energy-dispersive analysis by X-ray (EDAX) and image analysis, then added to cell cultures of a human monocytic cell line, U937, and stimulation of pro-osteolytic cytokines measured by ELISA.

Large quantities of PMMA cement debris were generated by the sliding wear of PMMA pins against Vaquasheened stainless steel plates in the method developed for this study. Both cements stimulated the release of pro-osteolytic TNFα from the U937 monocytic cell line, in a dose-dependent fashion. There was a trend towards greater TNFα release with Palacos cement than CMW cement at the same dose. Palacos particles also caused significant release of IL-6, another pro-osteolytic cytokine, while CMW did not. The particulate cement debris produced did not stimulate the release of GM-CSF or IL1β from the U937 cells. These results may explain the cytokine pathway responsible for bone resorption caused by particulate PMMA debris.

Radio-opaque additives are of value in surgical practice and clinical studies to quantify the relevance of these in vitro findings are required before the use of cement containing radio-opacifier is constrained.

We have examined 26 retrieved, failed titanium-alloy femoral stems. The clinical details, radiological appearances and the histology of the surrounding soft tissues in each patient were also investigated.

The stems were predominantly of the flanged design and had a characteristic pattern of wear. A review of the radiographs showed a series of changes, progressive with time. The first was lateral debonding with subsidence of the stem. This was followed by calcar resorption and fragmentation or fracture of the cement. Finally, osteolysis was seen, starting with a radiolucency at the cement-bone interface and progressing to endosteal cavitation.

Three histological appearances were noted: granulomatous, necrobiotic and necrotic. We suggest that an unknown factor, possibly related to the design of the stem, caused it to move early. After this, micromovement at the cement-stem interface led to the generation of particulate debris and fracture of the cement. A soft-tissue reaction to the debris resulted in osteolysis and failure of fixation of the prostheses.

We examined stainless-steel, cobalt-chrome, titanium and alumina and zirconia ceramic femoral heads retrieved at revision surgery. All the heads had articulated against ultra-high-molecular-weight-polyethylene (UHMWPE) acetabular cups. We studied the simulation of third-body damage and the wear of UHMWPE against the various materials used for the heads. The surfaces of the retrieved heads were analysed using a two-dimensional contacting profilometer. Third-body damage was characterised by the mean height of the scratches above the mean line (R_pm).

The alumina ceramic and zirconia ceramic retrieved heads were found to have significantly less damage. In laboratory studies the ceramics were also more resistant to simulated third-body damage than the metal alloys. We studied the wear of UHMWPE against the damaged counterfaces in simple configuration tests. The damaged ceramics produced less polyethylene wear than the damaged metal counterfaces. The wear factor of UHMWPE against the damaged materials was dependent on the amount of damage to the counterface (R_p). Our study has shown the benefit of using the harder and more damage-resistant ceramic materials for femoral heads.

Ultra-high-molecular-weight polyethylene (UHMWPE) components for total joint replacement generate wear particles which cause adverse biological tissue reactions leading to osteolysis and loosening. Sterilisation of UHMWPE components by gamma irradiation in air causes chain scissions which initiate a long-term oxidative process that degrades the chemical and mechanical properties of the polyethylene. Using a tri-pin-on-disc tribometer we studied the effect of ageing for ten years after gamma irradiation in air on the volumetric wear, particle size distribution and the number of particles produced by UHMWPE when sliding against a stainless-steel counterface.

The aged and irradiated material produced six times more volumetric wear and 34 times more wear particles per unit load per unit sliding distance than non-sterilised UHMWPE. Our findings indicate that oxidative degradation of polyethylene after gamma irradiation in air with ageing produces more wear.