Coagulase-negative staphylococci produce an exocellular glycolipid antigen which has potential as a serological marker of infection in bone. The value of this newly detected antigen was investigated by enzyme-linked immunosorbent assay (ELISA) in 15 patients with culture-proven infection of prostheses caused by Gram-positive bacteria. The antigen was purified by gel-permeation chromatography from the culture supernatants of coagulase-negative staphylococci grown in a chemically defined medium.

There were significant differences (p < 0.0001) between the serum IgG and IgM levels in patients with infection due to Gram-positive staphylococci and those of a control group of 32 patients with no infection. The ELISA test, which has potential for the diagnosis of infection, may be valuable in distinguishing between staphylococcal infection around prostheses and aseptic loosening.

Aims

Periprosthetic joint infections (PJIs) with prior multiple failed surgery for reinfection represent a huge challenge for surgeons because of poor vascular supply and biofilm formation. This study aims to determine the results of single-stage revision using intra-articular antibiotic infusion in treating this condition.

Revision arthroplasty after infection can often be complicated by both extensive bone loss and a relatively high rate of re-infection. Using allograft to address the bone loss in such patients is controversial because of the perceived risk of bacterial infection from the use of avascular graft material. We describe 12 two-stage revisions for infection in which segmental allografts were loaded with antibiotics using iontophoresis, a technique using an electrical potential to drive ionised antibiotics into cortical bone. Iontophoresis produced high levels of antibiotic in the allograft, which eluted into the surrounding tissues. We postulate that this offers protection from infection in the high-risk peri-operative period. None of the 12 patients who had two-stage revision with iontophoresed allografts had further infection after a mean period of 47 months (14 to 78)

Aims

Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision of hip arthroplasty necessitate removal of all bone cement from the femur. In our two centres, we have been using a cement-in-cement technique, leaving the distal femoral bone cement in selected patients for septic hip revision surgery, both for single and the first of two-stage revision procedures. A prerequisite for adoption of this technique is that the surgeon considers the cement mantle to be intimately fixed to bone without an intervening membrane between cement and host bone. We aim to report our experience for this technique.

Aims

Single-stage revision is not widely pursued due to restrictive inclusion criteria. In this study, we evaluated the results of single-stage revision of chronically infected total hip arthroplasty (THA) using broad inclusion criteria and cementless implants.

Aims

The management of acetabular defects at the time of revision hip arthroplasty surgery is a challenge. This study presents the results of a long-term follow-up study of the use of irradiated allograft bone in acetabular reconstruction.

Adverse reaction to wear and corrosion debris is a cause for concern in total hip arthroplasty (THA). Modular junctions are a potential source of such wear products and are associated with secondary pseudotumour formation.

We present a consecutive series of 17 patients treated at our unit for this complication following metal-on-highly cross-linked polyethylene (MoP) THA. We emphasise the risk of misdiagnosis as infection, and present the aggregate laboratory results and pathological findings in this series.

The clinical presentation was pain, swelling or instability. Solid, cystic and mixed soft-tissue lesions were noted on imaging and confirmed intra-operatively. Corrosion at the head–neck junction was noted in all cases. No bacteria were isolated on multiple pre- and intra-operative samples yet the mean erythrocyte sedimentation rate was 49 (9 to 100) and C-reactive protein 32 (0.6 to 106) and stromal polymorphonuclear cell counts were noted in nine cases.

Adverse soft–tissue reactions can occur in MoP THA owing to corrosion products released from the head–neck junction. The diagnosis should be carefully considered when investigating pain after THA. This may avoid the misdiagnosis of periprosthetic infection with an unidentified organism and mitigate the unnecessary management of these cases with complete single- or two-stage exchange.

Cite this article: Bone Joint J 2015;97-B:1024–1030.

We report the short-term follow-up, functional outcome and incidence of early and late infection after total hip replacement (THR) in a group of HIV-positive patients who do not suffer from haemophilia or have a history of intravenous drug use. A total of 29 patients underwent 43 THRs, with a mean follow-up of three years and six months (five months to eight years and two months). There were ten women and 19 men, with a mean age of 47 years and seven months (21 years to 59 years and five months). No early (< 6 weeks) or late (> 6 weeks) complications occurred following their THR. The mean pre-operative Harris hip score (HHS) was 27 (6 to 56) and the mean post-operative HHS was 86 (73 to 91), giving a mean improvement of 59 points (p = < 0.05, Student’s t-test). No revision procedures had been undertaken in any of the patients, and none had any symptoms consistent with aseptic loosening. This study demonstrates that it is safe to perform THR in HIV-positive patients, with good short-term functional outcomes and no apparent increase in the risk of early infection.

Cite this article: Bone Joint J 2014; 96-B:462–6.

We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81). We defined peri-prosthetic infection as an increased uptake of radioisotope in all the phases of triple-phase bone scintigraphy and validated these results against the histological and/or microbiology results in every case.

The positive and negative predictive values for the presence of infection were 83% and 93%, respectively. The diagnostic sensitivity was 88% and the specificity was 90%.

This study indicates that triple-phase bone scintigraphy is a useful tool in the detection of peri-prosthetic infection and offers a cost-effective method of screening.

Between 1990 and 2000, 123 hips in 110 patients were reconstructed for aseptic loosening using impaction bone grafting with frozen, irradiated, morsellised femoral heads and cemented acetabular components. This series was reported previously at a mean follow-up of five years. We have extended this follow-up and now describe the outcome of 86 hips in 74 patients at a mean of ten years. There have been 19 revisions, comprising nine for infection, seven for aseptic loosening and three for dislocation. In surviving acetabular reconstructions, union of the graft had occurred in 64 of 67 hips (95.5%).

Survival analysis for all indications at ten years was 83.3% (95% confidence interval (CI) 68 to 89) and 71.3% (95% CI 58 to 84) at 15 years.

Acetabular reconstruction using irradiated allograft and a cemented acetabular component is an effective method of reconstruction, providing results in the medium- to long-term comparable with those of reported series where non-irradiated freshly-frozen bone was used.