The treatment of peri-prosthetic joint infection (PJI) of the ankle is not standardised. It is not clear whether an algorithm developed for hip and knee PJI can be used in the management of PJI of the ankle. We evaluated the outcome, at two or more years post-operatively, in 34 patients with PJI of the ankle, identified from a cohort of 511 patients who had undergone total ankle replacement. Their median age was 62.1 years (53.3 to 68.2), and 20 patients were women. Infection was exogenous in 28 (82.4%) and haematogenous in six (17.6%); 19 (55.9%) were acute infections and 15 (44.1%) chronic. Staphylococci were the cause of 24 infections (70.6%). Surgery with retention of one or both components was undertaken in 21 patients (61.8%), both components were replaced in ten (29.4%), and arthrodesis was undertaken in three (8.8%). An infection-free outcome with satisfactory function of the ankle was obtained in 23 patients (67.6%). The best rate of cure followed the exchange of both components (9/10, 90%). In the 21 patients in whom one or both components were retained, four had a relapse of the same infecting organism and three had an infection with another organism. Hence the rate of cure was 66.7% (14 of 21). In these 21 patients, we compared the treatment given to an algorithm developed for the treatment of PJI of the knee and hip. In 17 (80.9%) patients, treatment was not according to the algorithm. Most (11 of 17) had only one criterion against retention of one or both components. In all, ten of 11 patients with severe soft-tissue compromise as a single criterion had a relapse-free survival. We propose that the treatment concept for PJI of the ankle requires adaptation of the grading of quality of the soft tissues.

Cite this article: Bone Joint J 2014;96-B:772–7.

There have been only a few small studies of patients with an infected shoulder replacement treated with a single-stage exchange procedure. We retrospectively reviewed 35 patients (19 men and 16 women) with a peri-prosthetic infection of the shoulder who were treated in this way. A total of 26 were available for clinical examination; three had died, two were lost to follow-up and four patients had undergone revision surgery. The mean follow-up time was 4.7 years (1.1 to 13.25), with an infection-free survival of 94%. The organisms most commonly isolated intra-operatively were Staphylococcus epidermidis and Propionibacterium acnes; two patients developed a recurrent infection. Three different types of prosthesis were used: a hemiarthroplasty, a hemiarthroplasty with a bipolar head and reverse prosthesis. The mean Constant-Murley score at final follow-up was 43.3 (14 to 90) for patients with a hemiarthroplasty, 56 (40 to 88) for those with a hemiarthroplasty with a bipolar head and 61 (7 to 90) for those with a reverse prosthesis. The mean hospital stay was 10.6 days (5 to 29). Single-stage exchange is a successful and practical treatment for patients with peri-prosthetic infection of the shoulder. Cite this article: Bone Joint J 2013;95-B:391–5

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

Peri-prosthetic infection remains a leading cause of revision surgery. Recent publications from the American Musculoskeletal Infection Society have sought to establish a definition of peri-prosthetic infection based on clinical findings and laboratory investigations. The limitations of their approach are discussed and an alternative definition is proposed, which it is felt may better reflect the uncertainties encountered in clinical practice

We analysed the serum C-reactive protein level, synovial fluid obtained by joint aspiration and five synovial biopsies from 145 knee replacements prior to revision to assess the value of these parameters in diagnosing late peri-prosthetic infection. Five further synovial biopsies were used for histological analysis. Samples were also obtained during the revision and incubated and analysed in an identical manner for 14 days. A total of 40 total knee replacements were found to be infected (prevalence 27.6%). The aspiration technique had a sensitivity of 72.5% (95% confidence interval (CI) 58.7 to 86.3), a specificity of 95.2% (95% CI 91.2 to 99.2), a positive predictive value of 85.3% (95% CI 73.4 to 100), a negative predictive value of 90.1% (95% CI 84.5 to 95.7) and an accuracy of 89%. The biopsy technique had a sensitivity of 100%, a specificity of 98.1% (95% CI 95.5 to 100), a positive predictive value of 95.2% (95% CI 88.8 to 100), a negative predictive value of 100% and an accuracy of 98.6%. C-reactive protein with a cut-off-point of 13.5 mg/l had a sensitivity of 72.5% (95% CI 58.7 to 86.3), a specificity of 80.9% (95% CI 73.4 to 88.4), a positive predictive value of 59.2% (95% CI 45.4 to 73.0), a negative predictive value of 88.5% (95% 81.0 to 96.0 CI) and an accuracy of 78.1%. We found that biopsy was superior to joint aspiration and C-reactive protein in the diagnosis of late peri-prosthetic infection of total knee replacements

INTRODUCTION. Peri-prosthetic fungal infection is generally considered more difficult to cure than a bacterial infection. Two-stage exchange is considered the gold standard of surgical treatment. A recent study, however, reported a favorable outcome after one stage exchange in selected cases where the fungus was identified prior to surgery. The routine one stage exchange policy for bacterial peri-prosthetic infection involves the risk of identifying a fungal infection mimicking bacterial infection solely on intraoperative samples, i.e. after reimplantation, realizing actually a one stage exchange for fungal infection without pre-operative identification of the responsible fungus, which is considered to have a poor prognosis. We report two such cases of prosthetic hip and knee fungal infection. Despite this negative characteristic, no recurrence of the fungal infection was observed. CASE N°1: A 78 year old patient was referred for loosening of a chronically infected total hip arthroplasty (Staphylococcus aureus and Streptococcus dysgalactiae). One stage exchange was performed. Intraoperative bacterial cultures remained sterile. Two fungal cultures were positive for Candida albicans. Antifungal treatment was initiated for three months. No infection recurrence was observed at three year follow up. CASE N° 2: A 53-year-old patient was referred for loosening of a chronically infected total knee prosthesis (Staphylococcus aureus methicillin susceptible, Klebsiella pneumoniae and Staphylococcus epidermidis). One stage exchange was performed. Intraoperative bacterial cultures remained sterile. Five fungal cultures were positive for Candida albicans. Antifungal treatment was initiated for three months. No infection recurrence was observed at two-year follow-up. DISCUSSION. This experience suggests that eradication of fungal infection of a total hip or knee arthroplasty may be possible after one stage exchange even in cases where the diagnosis of fungal infection was not known before surgery, when the fungus was not identified and its antifungal susceptibility has not been evaluated before surgery. It is however not possible to propose this strategy as a routine procedure. CONCLUSION. We suggest evaluating the results of one stage exchange for peri-prosthetic fungal infection on a larger scale

There are few reports in the literature of the diagnosis and treatment of the infected shoulder arthroplasty. Most deal with resection arthroplasty and two-stage exchange surgery. We present our results of one-stage exchange operation as treatment for the infected shoulder arthroplasty.

Our group comprised 16 patients (ten men, six women) with 16 infected arthroplasties. By the time of follow-up, two patients had died (mean 5.8 years), two could not be located and three had already undergone revision surgery. Nine patients were thus available for clinical examination and assessment.

The infections were largely caused by staphylococci, Propionibacterium species and streptococci. Two were early infections (within three months of surgery) and 14 were late infections. The mean follow-up was 5.8 years (13 months to 13.25 years) when the mean Constant-Murley score was 33.6 points and the mean University College of Los Angeles score 18.3 points.

Further revision was performed in three patients. One sustained a peri-prosthetic humeral fracture, another developed an acromial pseudarthrosis after transacromial surgery and the third suffered recurrent dislocations. No patient had a recurrence of infection.

A one-stage exchange procedure using antibiotic-loaded bone cement eradicated infection in all our patients and we suggest that such a procedure is at least as successful as either a resection arthroplasty or a two-stage exchange in the management of the infected shoulder arthroplasty.

This study reviews the predisposing features, the clinical, and laboratory findings at the time of diagnosis and the results of single-stage revision of prosthetic replacement of the elbow for infection.

Deep infection occurred in six of 305 (1.9%) primary total elbow replacements. The mean follow-up after revision was 6.8 years (6 months to 16 years) and the mean age at the time of revision was 62.7 years (56 to 74). All six cases with infection had rheumatoid arthritis and had received steroid therapy. The infective organism was Staphylococcus aureus. Four of the six elbows had a developed radiolucency around one component or the other. Successful single-stage exchange arthroplasty was carried out with antibiotic-loaded cement in five of the six cases. In one, the revision prosthesis had to be removed following recurrence of the infection. The functional result was good in three elbows, fair in one, poor in one and fair in the resection arthroplasty.

Introduction

Periprosthetic infection following lower extremity total joint arthroplasty often requires multiple surgical procedures and imposes a marked economic burden on the patient and hospital. The purpose of this study was to evaluate the incidence of surgical site infections in total joint arthroplasty patients who used an advance at-home pre-admission cutaneous preparation protocol and to compare these results to a cohort of patients who underwent standard in-hospital peri-operative preparation only.

Objectives. We wanted to investigate regional variations in the organisms reported to be causing peri-prosthetic infections and to report on prophylaxis regimens currently in use across England. Methods. Analysis of data routinely collected by Public Health England’s (PHE) national surgical site infection database on elective primary hip and knee arthroplasty procedures between April 2010 and March 2013 to investigate regional variations in causative organisms. A separate national survey of 145 hospital Trusts (groups of hospitals under local management) in England routinely performing primary hip and/or knee arthroplasty was carried out by standard email questionnaire. Results. Analysis of 189 858 elective primary hip and knee arthroplasty procedures and 1116 surgical site infections found statistically significant variations for some causative organism between regions. There was a 100% response rate to the prophylaxis questionnaire that showed substantial variation between individual trust guidelines. A number of regimens currently in use are inconsistent with the best available evidence. Conclusions. The approach towards antibiotic prophylaxis in elective arthroplasty nationwide reveals substantial variation without clear justification. Only seven causative organisms are responsible for 89% of infections affecting primary hip and knee arthroplasty, which cannot justify such widespread variation between prophylactic antibiotic policies. Cite this article: Bone Joint Res 2015;4:181–189

Peri-prosthetic joint infection (PJI) is one the most devastating complications of joint arthroplasty. Although PJI is an infrequent complication (the reported incidence is 1%-2% in the United States), it is the most common indication for revision total knee arthroplasty in the Medicare population and the third most frequent indication for revision total hip arthroplasty. Moreover, the prevalence of PJI appears to be on the rise, with a projected number exceeding 60,000 to 70,000 cases in the United States by 2020. It is estimated that more than 25% of revision procedures annually are attributed to PJI and this number is expected to increase in the upcoming years. The increase in the prevalence of obesity, diabetes, and other comorbidities among the patient population and the emergence of resistant infecting organisms are some of the reasons for the expected rise in the number of infections that medical community will witness. The challenges that PJI present to the orthopaedic community are on many fronts. Prevention of PJI has proven to be a difficult task indeed. Effective strategies for prevention of PJI are being refined. The Center for Disease Control will be publishing its updated Surgical Site Prevention Guidelines in the next few months that consists of specific recommendations for prevention of PJI. In recent years, strides are made in introducing novel molecular techniques for diagnosis of PJI, which may stand to change our practices. The current surgical technique for management of PJI, besides the immense cost, fall short of delivering high success to the patients. The major problem in eradication of infection relates to formation of biofilm on the implant surface and internalization of the organisms by affected cells. Biofilm is a sophisticated structure comprising of organisms embedded in multiple layers of glycoccalyx that allows the organisms to evade host immunity and is impenetrable to antibiotics. These organisms are capable of communicating through molecular mechanisms such as quorum sensing that affords them advantage for survival in the host environment. In recent years strategies to prevent colonization of the implant surface, an essential first step in formation of biofilm, or biofilm disruption techniques have been introduced. A recent International Consensus meeting on PJI that assembled more than 350 experts identified some of the best practices in this field and identified areas in need of future research. Moving into the future, the field of orthopaedics in general and PJI in particular stand to benefit from the discoveries in the field of molecular diagnostics, metabolomics and epigenetics

To report our experience with the use of local antibiotic co-delivery with a synthetic bone graft substitute during a second stage re-implantation of an infected proximal humeral replacement. A 72 year old man was admitted to our department with a pathological fracture through an osteolytic lesion in the left proximal humerus, due to IgG Myelomatosis. He was initially treated with a cemented proximal humerus replacement hemiarthroplasty. Peri-prosthetic joint infection (PJI) with significant joint distention was evident three weeks post operatively. Revision surgery confirmed presence of a large collection of pus and revealed disruption of the soft tissue reattachment tube, as well as complete retraction of rotator cuff and residual capsule. All modular components were removed and an antibiotic-laden cement spacer (1.8g of Clindamycin and Gentamycin, respectively) was implanted onto the well-fixed cemented humeral stem. Initial treatment with i.v. Amoxicillin/Clavulanic acid was changed to Rifampicin and Fusidic Acid during a further 8 weeks after cultures revealed growth of S. epidermidis. During second stage revision, a hybrid inverse prosthesis with silver coating was implanted, with a total of 20 ml Cerament ™G (injected into the glenoid cavity prior to insertion of the base plate and around the humeral implant-bone interface) and again stabilized with a Trevira tube. Unfortunately, this prosthesis remained unstable, ultimately requiring re-revision to a completely new constrained reverse prosthesis with a custom glenoid shell and silver-coated proximal humeral component. 18 months postoperatively, the patient's shoulder remains pain free and stable, without signs of persistent or reinfection since the initial second stage revision. The function however, unfortunately remains poor. This case report illustrates the application of an antibiotic-eluting bone graft substitute in a specific clinical situation, where co-delivery of an antibiotic together with a bone remodeling agent may be beneficial to simultaneously address PJI as well as poor residual bone quality

Aim. Advocates of Debridement-Antibiotics-and-Implant-Retention (DAIR) in hip peri-prosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis-bone interface is likely to lead to better survival and functional outcome compared to revision. However, no evidence supports this. This case-control study's aims were to compare outcome of DAIRs for infected 1° total hip arthroplasty (THA) with outcomes following 1° THA and 2-stage revisions of infected 1° THAs. Method. We retrospectively reviewed all DAIRs, performed for confirmed infected 1° THR (DAIR-Group, n=80), in our unit between 1997–2013. Data recorded included patient demographics, medical history, type of surgery and organism identified. Outcome measures included complications, mortality, implant survivorship and functional outcome using the Oxford Hip Score (OHS). Outcome was compared with 2 control groups matched for gender and age; a cohort of 1° THA (1°-THA-Group, n=120) and a cohort of 2-stage revisions for infection (2-Stage-Revision-Group, n=66). Results. The mean age at DAIR was 69 years and mean follow-up was 8 years (SD:5). 60% of DAIRs were for early PJI (< six weeks). Greater infection eradication with DAIR was detected with early-PJI, interval less than a week between onset of symptoms and exchange of modular components with the DAIR procedure. Infection eradication, complications and re-operation rates were similar in the DAIR- and 2-stage-revision Groups (p>0.05). For hips with successful infection eradication with DAIR, the 5-yr survival (98%) was similar to the 1°THA-Group (98%) (p=0.3). The DAIR-Group had inferior OHS (38) compared to the 1°THA-Group (42) (p=0.02) but significantly better OHS compared to the 2-stage-revision-Group (31) (p=0.008). Patients that required only one DAIR for infection eradication had similar OHS (41) to the 1° THA-Group (p=0.2). Conclusions. DAIRs are associated with similar complication and infection eradication to 2-stage revisions. Exchange of modular components is advised for improved chances of infection eradication. Functional outcome following DAIRs was better than a 2-stage revision and as good as that of a 1° THA if a single DAIR was necessary for infection eradication

Periprosthetic joint infection (PJI) is a devastating complication of total hip arthroplasty (THA). According to registry-based studies, some bearing couples are associated with an increased risk of PJI. The recent International Consensus on Periprosthetic Joint Infection stated that metal-on-metal (MOM) bearing surface appeared to be associated with a higher incidence of PJI. Based on emerging reports, the incidence of PJI appears to be different among different bearing surfaces. We conducted a multi-institutional study attempting to study this exact issue. The purpose of the study was to determine whether there was any difference in the incidence of PJI in two commonly used bearing couples (metal- on-polyethylene versus ceramic-on-polyethylene).

Based on a retrospective multi-institutional query all patients who received primary THA with MOP or COP bearing surfaces performed during 2005–2009 in two high-volume arthroplasty centers were identified. Demographic factors, comorbidities, length of hospital stay, complications and other relevant information were extracted. PJI was defined based on the MSIS (International Consensus) criteria. Multivariate analysis was performed to determine whether bearing coupling was independently correlated with PJI.

In our data, 25/2,921 (0.9%) patients with MOP and 11/2,643 (0.4%) patients with COP developed PJI. This difference was statistically significant (p=0.01). After the multivariate analysis, controlling for potential confounders (age, body mass index and length of hospital stay, Charlson comorbidity index), MOP bearing surface was found to be an independent factor correlating with higher incidence of PJI (odds ratio: 2.6, 95% confidence interval: 1.02–6.54, p=0.04).

The finding of this study, and others from centers in Europe, suggest that the bearing surface may have an influence on the incidence of PJI. Although, we had originally thought that ceramic bearing surfaces may be used in younger and healthier patients, the multivariate analyses that controlled for all these variables confirms that use of metal femoral head is an independent risk factor for development of PJI. The finding of this study is compelling and begs for future basic science mechanistic investigations.

There is limited evidence in the literature suggesting that ceramic-on-ceramic (CoC) THA is associated with lower risk of revision for prosthetic joint infection (PJI) than other bearing combinations especially metal-on-poly (MoP) and metal-on-metal (MoM). Pitto and Sedel reported hazard ratios of 1.3 – 2.1 for other bearing surfaces versus CoC. Of interest, the PJI rate was not significantly lower in the first 6 months, when most infections occur, but only became significant in the long term. While factors such as patient age, fixation, mode, OR type, use of body exhaust suits, and surgeon volume were considered in the multivariate analysis, BMI, medical comorbidities, and ASA class were not. This is a major weakness that casts doubt on the conclusion, since those three factors are MAJOR risk factors for PJI AND all three factors are more likely to be unevenly distributed, and much more likely present in groups other than CoC. The data was also limited by the fact that it was drawn from a retrospective review of National Registry data, The New Zealand Joint Registry. While similar findings have recently been reported from the Australian Joint Registry, the danger in attributing differences in outcomes to implants alone is possibly the single greatest danger in interpreting registry results. While device design can impact implant survival, other factors such as surgical technique, surgeon, hospital, and especially patient factors have a far greater likelihood of explaining differences in observed results. A recent report from the same New Zealand joint registry reported that obesity, ASA class, surgical approach, and trainee operations all were associated with higher PJI and all would be more likely in non-CoC THAs. Accuracy of diagnosis is also a major concern. Revision for trunnionosis is more common in non-CoC THA and is frequently misdiagnosed as PJI.

Numerous non-registry studies and reviews have compared PJI in CoC vs. other bearings and none have concluded than the incidence of PJI differed significantly.

We evaluated the clinical results and complications after extra-articular resection of the distal femur and/or proximal tibia and reconstruction with a tumour endoprosthesis (MUTARS) in 59 patients (mean age 33 years (11 to 74)) with malignant bone or soft-tissue tumours. According to a Kaplan–Meier analysis, limb survival was 76% (95% confidence interval (CI) 64.1 to 88.5) after a mean follow-up of 4.7 years (one month to 17 years). Peri-prosthetic infection was the most common indication for subsequent amputation (eight patients). Survival of the prosthesis without revision was 48% (95% CI 34.8 to 62.0) at two years and 25% (95% CI 11.1 to 39.9) at five years post-operatively. Failure of the prosthesis was due to deep infection in 22 patients (37%), aseptic loosening in ten patients (17%), and peri-prosthetic fracture in six patients (10%). Wear of the bearings made a minor revision necessary in 12 patients (20%). The mean Musculoskeletal Tumor Society score was 23 (10 to 29). An extensor lag > 10° was noted in ten patients (17%).

These results suggest that limb salvage after extra-articular resection with a tumour prosthesis can achieve good functional results in most patients, although the rates of complications and subsequent amputation are higher than in patients treated with intra-articular resection.

Cite this article: Bone Joint J 2013;95-B:1425–31.

Aim

Compare clinical outcomes following staged revision arthroplasty for periprosthetic joint infection (PJI) secondary to either multidrug resistant (MDR) bacteria or non-MDR (NMDR) bacteria.

Background: Chronic prosthetic joint infection is a cause of patient morbidity and can be challenging to treat. Surgeons performing revision arthroplasty of the hip and knee are confronted with a growing number of patients with extensive loss of bone stock. The use of a modular endoprosthesis is a possible method of treatment in such patients.

Aim: The purpose of this study was to assess the functional outcomes and the success of a single and two stage revision procedure in eradicating chronic prosthetic joint infection using a femoral endoprosthesis.

Methods: A prospective database was reviewed of 20 patients who underwent a proximal, total or distal femoral endoprosthetic replacement after chronic prosthetic infection. Radiographs performed at the time of latest follow up were evaluated for signs of loosening, osteomyelitis and implant failure. The functional status was assessed using the Short Form (SF)-36 health survey score, Toronto extremity salvage score (TESS) and the Enneking score.

Results: Thirteen patients underwent a single stage revision procedure and seven had been treated with a staged revision. At the latest follow up none of the 13 patients treated with a single stage procedure had evidence of ongoing infection. Of the seven patients who had a staged revision, 3 patients had evidence of ongoing infection. The mean pre operative Enneking score for the entire group was 17.1 points and this improved to 47.5 points post operatively (p< 0.0002). The mean pre operative TESS score for the entire group was 42% and this improved to 59% post operatively (p< 0.005). There was also a statistically significant improvement in all of the components of the SF-36 score.

Conclusion: We believe that the use of a modular endo-prosthesis in the treatment of chronic prosthetic joint infection is a successful and viable option in eradicating infection, preserving the limb and providing a good functional result.

Aim

Dissolvable antibiotic-loaded calcium sulphate beads have been utilized for management of periprosthetic joint infection (PJI) and for aseptic revision arthroplasty. However, wound drainage and toxic reactive synovitis have been substantial problems in prior studies. Currently a commercially pure, physiologic product has been introduced that may reduce complications associated with this treatment modality. We aim to answer the question: does a commercially pure, physiologic version of antibiotic-loaded calcium sulfate beads reduce wound drainage and provide efficacious treatment for PJI and aseptic revision arthroplasty?