Aims. Cutibacterium acnes (C. acnes; previously known as Propionibacterium acnes or P. acnes) periprosthetic hip and knee infections are under-reported. While culture contamination with C. acnes occurs, true infections are important to recognize and treat. We sought to describe the demographics and treatment outcomes of patients with C. acnes periprosthetic joint infections (PJIs) of the hip and knee. Methods. Patients with C. acnes PJI between January 2005 and December 2018 were retrospectively reviewed utilizing the institutional total joint registry. Patients with monomicrobial PJI and two or more positive cultures were considered to have true C. acnes PJI. Patients with polymicrobial infection or with only one positive culture were excluded. This resulted in 35 PJIs (21 hips and 14 knees); the patients’ mean age was 63 years (35 to 84) and 15 (43%) were female. Mean follow-up was five years (1 to 14). Results. The median time to positive culture was five days (IQR 5 to 6) and median synovial fluid cell count was 22,583 cells (IQR 15,200 to 53,231). The median ESR was 25 mm/hr (IQR 7 to 37), and CRP was 15 mg/l (IQR 3 to 29). Of the 35 PJIs, 18 (51%) were treated with chronic antibiotic suppression without surgical intervention, and the remainder were treated with two-stage exchange arthroplasty. The two-year survival free of any revision was 94%. Four patients failed treatment due to symptomatic infection, with three treated with two-stage exchange and one treated with irrigation and debridement with modular component exchange for a survival rate of 89% and 83% at two and five years, respectively. Conclusion. Laboratory evidence of C. acnes PJI in this cohort was typical compared to more conventional organisms. Cultures grew more quickly than previously thought in patients with C. acnes PJI. Treatment with two-stage exchange or chronic antibiotic suppression alone both had few treatment failures at mid-term follow-up. Cite this article: Bone Joint J 2024;106-B(12):1426–1430

Aims

Breast cancer survivors have known risk factors that might influence the results of total hip arthroplasty (THA) or total knee arthroplasty (TKA). This study evaluated clinical outcomes of patients with breast cancer history after primary THA and TKA.

As part of the government’s initiative to reduce waiting times for major joint surgery in Wales, the Cardiff and Vale NHS Trust sent 224 patients (258 knees) to the NHS Treatment Centre in Weston-Super-Mare for total knee replacement. The Kinemax total knee replacement system was used in all cases. The cumulative survival rate at three years was 79.2% (95% confidence interval (CI) 69.2 to 86.8) using re-operation for any cause as an endpoint and 85.3% (95% CI 75.9 to 91.8) using aseptic revision as an endpoint. This is significantly worse than that recorded in the published literature. These poor results have resulted in a significant impact on our service

Aims

It can be extremely challenging to determine whether to perform reimplantation in patients who have contradictory serum inflammatory markers and frozen section results. We investigated whether patients with a positive frozen section at reimplantation were at a higher risk of reinfection despite normal ESR and CRP.

Aims

To investigate whether chronic kidney disease (CKD) is associated with the risk of all-cause revision or revision due to a periprosthetic joint infection (PJI) after primary hip or knee arthroplasty.

The Kinematic Stabilizer is a posterior-cruciate-substituting design of total knee replacement. We have reviewed 109 primary total knee replacements in 95 patients at a mean follow-up time of 12.7 years (10 to 14). We used survival analysis with failure defined as revision of the implant. This gave a cumulative survival rate of 95% (95% CI± 5%) at ten years and 87% (± 10%) at 13 years. These results from an independent centre confirm the value of an established design of cemented total knee replacement and question the wisdom of the introduction of modifications and new designs without properly controlled trials

From a series of 135 patients (146 prostheses) who had had primary hip replacement in 1975 and 1976 we reported the outcome at ten years in 83 surviving patients in 1988 and that at 15 years in 44 surviving patients in 1994. Now, 22 years after the operation, we have reviewed the 21 patients who are still alive. Nineteen (20 hips) of these 21 patients (22 hips) with a mean age of 85.7 years still had their original prosthesis. Most patients were satisfied with the result, although the level of activity in many was reduced because of increasing age and other medical problems. The stem was stable in all 20 hips. Only one cup was definitely loose. Wear was observed in 40% of the cups but this was not a clinical problem. At the 22-year follow-up the cumulative survival rate of the prosthesis was 85%, of the stem 91% and of the cup 88%. Since 1975, 11 (7.5%) of the original 146 prostheses have been revised

Aims

In the absence of an identified organism, single-stage revision is contraindicated in prosthetic joint infection (PJI). However, no studies have examined the use of intra-articular antibiotics in combination with single-stage revision in these cases. In this study, we present the results of single-stage revision using intra-articular antibiotic infusion for treating culture-negative (CN) PJI.

Aims

To investigate the outcomes of treatment of streptococcal periprosthetic joint infection (PJI) involving total knee and hip arthroplasties.

Aims. Positive cultures are not uncommon in cases of revision total knee and hip arthroplasty (TKA and THA) for presumed aseptic causes. The purpose of this study was to assess the incidence of positive intra-operative cultures in presumed aseptic revision of TKA and THA, and to determine whether the presence of intra-operative positive cultures results in inferior survival in such cases. Patients and Methods. A retrospective cohort study was assembled with 679 patients undergoing revision knee (340 cases) or hip arthroplasty (339 cases) for presumed aseptic causes. For all patients three or more separate intra-operative cultures were obtained. Patients were diagnosed with a previously unsuspected prosthetic joint infection (PJI) if two or more cultures were positive with the same organism. Records were reviewed for demographic details, pre-operative laboratory results and culture results. The primary outcome measure was infection-free implant survival at two years. Results. The incidence of unsuspected PJI was 27 out of 340 (7.9%) in TKA and 41 out of 339 (12.1%) in THA. Following revision TKA, the rate of infection-free implant survival in patients with an unsuspected PJI was 88% (95% confidence intervals (CI) 60 to 97) at two years compared with 98% (95% CI 94 to 99) in patients without PJI (p = 0.001). After THA, the rate of survival was similar in those with unsuspected PJI (92% (95% CI 73 to 98) at two years) and those without (94% (95% CI 89 to 97), p = 0.31). Conclusion. Following revision of TKA and THA for aseptic diagnoses, around 10% of cases were found to have positive cultures. In the knee, such cases had inferior infection-free survival at two years compared with those with negative cultures; there was no difference between the groups following THA. Cite this article: Bone Joint J 2017;99-B:1482–9

Objectives

Unicompartmental knee arthroplasty (UKA) is a potential treatment for isolated bone on bone osteoarthritis when limited to a single compartment. The risk for revision of UKA is three times higher than for total knee arthroplasty (TKA). The aim of this review was to discuss the different revision options after UKA failure.

We reviewed the outcome of 69 uncemented, custom-made, distal femoral endoprosthetic replacements performed in 69 patients between 1994 and 2006. There were 31 women and 38 men with a mean age at implantation of 16.5 years (5 to 37). All procedures were performed for primary malignant bone tumours of the distal femur. At a mean follow-up of 124.2 months (4 to 212), 53 patients were alive, with one patient lost to follow-up. All nine implants (13.0%) were revised due to aseptic loosening at a mean of 52 months (8 to 91); three implants (4.3%) were revised due to fracture of the shaft of the prosthesis and three patients (4.3%) had a peri-prosthetic fracture. Bone remodelling associated with periosteal cortical thinning adjacent to the uncemented intramedullary stem was seen in 24 patients but this did not predispose to failure. All aseptically loose implants in this series were diagnosed to be loose within the first five years.

The results from this study suggest that custom-made uncemented distal femur replacements have a higher rate of aseptic loosening compared to published results for this design when used with cemented fixation. Loosening of uncemented replacements occurs early indicating that initial fixation of the implant is crucial.

Cite this article: Bone Joint J 2014;96-B:263–9.

We compared the length of hospitalisation, rate of infection, dislocation of the hip and revision, and mortality following primary hip and knee arthroplasty for osteoarthritis in patients with Alzheimer’s disease (n = 1064) and a matched control group (n = 3192). The data were collected from nationwide Finnish health registers. Patients with Alzheimer’s disease had a longer peri-operative hospitalisation (median 13 days vs eight days, p < 0.001) and an increased risk for hip revision with a hazard ratio (HR) of 1.76 (95% confidence interval (CI) 1.03 to 3.00). Dislocation was the leading indication for revision. There was no difference in the rates of infection, dislocation of the hip, knee revision and short-term mortality. In long-term follow-up, patients with Alzheimer’s disease had a higher mortality (HR 1.43; 95% CI 1.22 to 1.70), and only one third survived ten years post-operatively. Increased age and comorbidity were associated with longer peri-operative hospitalisation in patients with Alzheimer’s disease.

Cite this article: Bone Joint J 2015;97-B:654–61.

Between 1988 and 1998 we implanted 318 total hip replacements (THRs) in 287 patients using the Plasmacup (B. Braun Ltd, Sheffield, United Kingdom) and a conventional metal-on-polyethylene articulation. The main indications for THR were primary or secondary osteoarthritis.

At follow-up after a mean 11.6 years (7.6 to 18.4) 17 patients had died and 20 could not be traced leaving a final series of 280 THRs in 250 patients. There were 62 revisions (22.1%) in 59 patients. A total of 43 acetabular shells (15.4%) had been revised and 13 (4.6%) had undergone exchange of the liner. The most frequent indications for revision were osteolysis and aseptic loosening, followed by polyethylene wear. The mean Kaplan-Meier survival of the Plasmacup was 91% at ten years and 58% at 14 years. Osteolysis was found around 36 (17.1%) of the 211 surviving shells. The median annual rate of linear wear in the surviving shells was 0.12 mm/year and 0.25 mm/year in those which had been revised (p < 0.001). Polyethylene wear was a strong independent risk factor for osteolysis and aseptic loosening. The percentage of patients with osteolysis increased proportionately with each quintile of wear-rate.

There is a high late rate of failure of the Plasmacup. Patients with the combination of this prosthesis and bearing should be closely monitored after ten years.

Survival analysis is an important tool for assessing the outcome of total joint replacement. The Kaplan-Meier method is used to estimate the incidence of revision of a prosthesis over time, but does not account appropriately for competing events which preclude revision. In the presence of competing death, this method will lead to statistical bias and the curve will lose its interpretability. A valid comparison of survival results between studies using the method is impossible without accounting for different rates of competing events. An alternative and easily applicable approach, the cumulative incidence of competing risk, is proposed. Using three simulated data sets and realistic data from a cohort of 406 consecutive cementless total hip prostheses, followed up for a minimum of ten years, both approaches were compared and the magnitude of potential bias was highlighted. The Kaplan-Meier method overestimated the incidence of revision by almost 4% (60% relative difference) in the simulations and more than 1% (31.3% relative difference) in the realistic data set. The cumulative incidence of competing risk approach allows for appropriate accounting of competing risk and, as such, offers an improved ability to compare survival results across studies.