There is sufficient evidence that specialised orthopaedic services, in the form of ‘hub’ or specialist centres, which undertake a high volume of workload in revision arthroplasty generate superior outcomes.

The East Midlands South Orthopaedic Network (EMSSON) was set up in 2015 and is an example of a ‘hub and spoke’ network. The network has recently undergone adaptation in light of the COVID-19 pandemic. There is paucity of data considering the impact of such adaptations in a post-pandemic era and on adherence to advice given.

Two data sets were obtained from the EMSSON data base, pertaining to pre and post pandemic eras respectively. Datasets were analysed and compared for case volumes, proportion of overall arthroplasty volume discussed and adherence to agreed management plans.

Dataset one included 107 cases, of these 99 cases were discussed (54 knees and 45 hips). This equates to 35% of total revision arthroplasty volume recorded in the National Joint Registry (NJR), by units involved in the network. A change of plan was recommended in 45/99 cases (45%), of these 41 (93%) were adhered to. Dataset two included 99 cases, of these 98 were discussed (39 knees and 59 hips). This equates 68% of revision arthroplasty volume performed by the region according to NJR records. A change in plan was recommended in 20 cases (20.5%), all of which were adhered to. One case was referred to the ‘hub’ for surgery.

Following the implementation of recent adaptations, the efficiency of the EMSSON network has significantly improved. A greater volume and proportion of revision arthroplasty cases are now being discussed on a weekly basis. Management plans for which adaptations are suggested have decreased, indicating an educational value of such networking practices. Adherence to agreed plans also showed improvement (p<0.03).

These findings demonstrate a trend towards NHS England's target of 100% of revision arthroplasty cases undergoing MDT discussion. Changes made in light of the Covid-pandemic, are felt to have contributed significantly to the overall performance of regional networking and have been well received by consultants involved.

Aims. 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. Materials and Methods. Equal-sized pieces of Ta and titanium (Ti) acetabular components were sterilised and incubated with a low dose inoculum of either Staphylococcus (S.) aureus or S. epidermidis for 24 hours. After serial dilution, colony forming units (cfu) were quantified on Mueller-Hinton agar plates. In order to establish whether biofilms formed to a greater extent on one material than the other, these Ta and Ti pieces were then washed twice, sonicated and washed again to remove loosely adhered planktonic bacteria. They were then re-incubated for 24 hours prior to quantifying the number of cfu. All experiments were performed in triplicate. Results. More than 1x10. 8. cfu/ml were observed in both the Ta and Ti experiments. After washing and sonication, more than 2x10. 7. cfu/ml were observed for both Ta and Ti groups. The results were the same for both S. aureus and S. epidermidis. Conclusion. Compared with Ti controls, Ta did not demonstrate any intrinsic antibacterial activity or ability to inhibit biofilm formation. Hence, intrinsic antimicrobial properties of Ta do not account for the previously observed reduction in the frequency of subsequent infections when Ta was used in revision procedures. . Cite this article: Bone Joint J 2017;99-B:1153–6

Introduction. Tantalum 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 as to whether Tantalum components are protective against infection in revision surgery. This is based on a retrospective, single institution review, of revision cases comparing tantalum with titanium acetabular implants, which reported a lower incidence of subsequent infection in the tantalum group. This laboratory study aimed to establish if tantalum had any intrinsic antibacterial properties against planktonic bacteria or ability to inhibit biofilm formation. Materials and methods. Equal sized pieces of tantalum (Trabecular metal, Zimmer UK) and titanium (Trilogy, Zimmer UK) were sterilised and then incubated with a low dose inoculum of either Staphylococcus aureus or Staphylococcus epidermidis for 24 hours. After serial dilution, colony forming units were quantified on MH agar plates. To establish the ability to inhibit biofilm formation these tantalum and titanium pieces were then washed twice, sonicated and washed again to remove loosely adhered planktonic bacteria. They were then re-incubated for 24 hours prior to quantifying colony forming units. All experiments were performed in triplicate. Results. More than 1×10. 8. cfu/ml were observed in both the titanium and tantalum experiments. After washing and sonication more than 2×10. 7. cfu/ml were observed for both tantalum and titanium groups. The results were the same for both Staph Aureus and Staph Epidermidis. Discussion. Compared with titanium controls tantalum did not demonstrate any intrinsic antibacterial activity or ability to inhibit biofilm formation. The intrinsic properties of tantalum do not account for the previously observed reduction in subsequent infection when tantalum was used in the revision procedure. Conclusion. Tantalum does not have any intrinsic antimicrobial properties or ability to inhibit biofilm formation

The World Health Organization (WHO) and the Centre for Disease Control and Prevention (CDC) recently published guidelines for the prevention of surgical site infection. The WHO guidelines, if implemented worldwide, could have an immense impact on our practices and those of the CDC have implications for healthcare policy in the United States.

Our aim was to review the strategies for prevention of periprosthetic joint infection in light of these and other recent guidelines.

Cite this article: Bone Joint J 2017;99-B(4 Supple B):3–10.

We inserted an electrode up the femoral neck into the femoral head of ten patients undergoing a metal-on-metal hip resurfacing arthroplasty through a posterior surgical approach and measured the oxygen concentration during the operation. In every patient the blood flow was compromised during surgery, but the extent varied. In three patients, the oxygen concentration was zero at the end of the procedure. The surgical approach caused a mean 60% drop (p < 0.005) in oxygen concentration while component insertion led to a further 20% drop (p < 0.04). The oxygen concentration did not improve significantly on wound closure. This study demonstrates that during hip resurfacing arthroplasty, patients experience some compromise to their femoral head blood supply and some have complete disruption.

In this study of 41 patients, we used proteomic, Western blot and immunohistochemical analyses to show that several reactive oxygen species scavenging enzymes are expressed differentially in patients with primary osteoarthritis and those with non-loosening and aseptic loosening after total hip replacement (THR). The patients were grouped as A (n = 16, primary THR), B (n = 10, fixed THR but requiring revision for polyethylene wear) and C (n = 15, requiring revision due to aseptic loosening) to verify the involvement of the identified targets in aseptic loosening. When compared with Groups A and B, Group C patients exhibited significant up-regulation of transthyretin and superoxide dismutase 3, but down-regulation of glutathione peroxidase 2 in their hip synovial fluids. Also, higher levels of superoxide dismutase 2 and peroxiredoxin 2, but not superoxide dismutase 1, catalase and glutathione perioxidase 1, were consistently detected in the hip capsules of Group C patients.

We propose that dysregulated reactive oxygen species-related enzymes may play an important role in the pathogenesis and progression of aseptic loosening after THR.

Based on the first implementation of mixing antibiotics into bone cement in the 1970s, the Endo-Klinik has used one stage exchange for prosthetic joint infection (PJI) in over 85% of cases. Looking carefully at current literature and guidelines for PJI treatment, there is no clear evidence that a two stage procedure has a higher success rate than a one-stage approach. A cemented one-stage exchange potentially offers certain advantages, mainly based on the need for only one operative procedure, reduced antibiotics and hospitalisation time. In order to fulfill a one-stage approach, there are obligatory pre-, peri- and post-operative details that need to be meticulously respected, and are described in detail. Essential pre-operative diagnostic testing is based on the joint aspiration with an exact identification of any bacteria. The presence of a positive bacterial culture and respective antibiogram are essential, to specify the antibiotics to be loaded to the bone cement, which allows a high local antibiotic elution directly at the surgical side. A specific antibiotic treatment plan is generated by a microbiologist. The surgical success relies on the complete removal of all pre-existing hardware, including cement and restrictors and an aggressive and complete debridement of any infected soft tissues and bone material. Post-operative systemic antibiotic administration is usually completed after only ten to 14 days.

Cite this article: Bone Joint J 2013;95-B, Supple A:77–83.

In 12 patients, we measured the oxygen concentration in the femoral head-neck junction during hip resurfacing through the anterolateral approach. This was compared with previous measurements made for the posterior approach. For the anterolateral approach, the oxygen concentration was found to be highly dependent upon the position of the leg, which was adjusted during surgery to provide exposure to the acetabulum and femoral head. Gross external rotation of the hip gave a significant decrease in oxygenation of the femoral head. Straightening the limb led to recovery in oxygen concentration, indicating that the blood supply was maintained. The oxygen concentration at the end of the procedure was not significantly different from that at the start.

The anterolateral approach appears to produce less disruption to the blood flow in the femoral head-neck junction than the posterior approach for patients undergoing hip resurfacing. This may be reflected subsequently in a lower incidence of fracture of the femoral neck and avascular necrosis.