Periprosthetic joint infection following hip hemiarthroplasty : factors associated with infection and treatment outcome

Mapping Staphylococcus aureus at Early and Late Stages of Infection in a Clinically Representative Hip Prosthetic Joint Infection Rat Model

Prosthetic joint infection (PJI) continues to be a devastating complication following total joint replacement surgeries where Staphylococcus aureus is the main offending organism. To improve our understanding of the disease pathogenesis, a histological analysis of infected peri-implant tissue in a hip PJI rat model was utilized to assess S. aureus spread and tissue reaction at early and late stages of infection. Sprague-Dawley rats were used and received a left cemented hip hemiarthroplasty using a 3D-printed titanium femoral stem. The rats received an intra-articular injection of S. aureus Xen36. These infected rats were sacrificed either at 3 days post-infection (early-stage infection) or at 13-days post-infection (late-stage infection). The femoral and acetabular tissues of all animals were harvested at euthanasia. Histological analysis for the harvested tissue was performed using immunohistochemistry, hematoxylin and eosin, as well as Masson's trichrome stains. Histological examination revealed significant quantitative and qualitative differences in peri-implant tissue response to infection at early and late stages. This hip PJI rat model identified clear histologic differences between early and late stages of S. aureus infection and how quickly bacterial infiltration could occur. These findings can provide insight into why certain surgical strategies like debridement and antibiotics may be associated with high failure rates.

Risk factors of periprosthetic joint infection after hemiarthroplasty for displaced femoral neck fracture in the elderly: Analysis of 1619 cases in the multicenter database

PURPOSE

This multicenter retrospective study focuses on understanding the incidence, causative bacteria, and risk factors for Periprosthetic Joint Infection (PJI) following hemiarthroplasty in elderly patients with displaced femoral neck fractures (FNF).

METHODS

From 2016 to 2020, 1,619 patients were diagnosed with displaced FNFs and treated surgically across 11 centers. After exclusions, 1,438 patients (399 men and 1,039 women) were included in the study, averaging 82.1 years in age and 20.2 kg/m² in BMI, observed over 25.7 months on average. Data on demographics, medical history, surgical details, and complications were described.

RESULTS

PJI occurred in 20 of the 1438 patients (1.4%). The causative organism was methicillin-susceptible Staphylococcus aureus in 6 patients and methicillin-resistant S. aureus in 6 patients. In patients' backgrounds, the average age was slightly higher in the non-PJI group (82.1 years) compared to the PJI group (80.4 years). There was a higher percentage of males in the PJI group (45%) than in the non-PJI group (27.5%). Drug history showed that the prevalence of anticoagulant use in the PJI group was 25%. Peripheral vascular disease and diabetes mellitus were more prevalent in the PJI group. Most patients in both groups were independent in daily activities. The blood transfusion rate was significantly higher in the PJI group (50%) than in the non-PJI group (23.8%). Notably, the incidence of hematoma was higher in the PJI group (40%).

CONCLUSION

This multicenter retrospective study demonstrates a low incidence (1.4%) of PJI in elderly patients undergoing hemiarthroplasty for FNF, primarily due to Staphylococcus aureus. Increased usage of antiplatelets and anticoagulants, as well as comorbidities related to atherosclerosis, like peripheral vascular disease and diabetes mellitus, were observed in patients with PJI. Additionally, these patients experienced higher rates of blood transfusion and postoperative hematomas, highlighting the need for careful management. It should be noted, however, that this finding is a conclusion limited by study design issues, including the retrospective design, small PJI sample size, and variability in treatment approaches.

5-Factor Modified Frailty Index as a Predictor of Outcomes After Hemiarthroplasty or Total Hip Arthroplasty for Femoral Neck Fracture

INTRODUCTION

Although the 5-factor modified frailty index (mFI-5) has been shown to be an independent predictor of complications after primary total hip arthroplasty (THA), its predictive value has not been evaluated in the setting of hip fracture. We therefore assessed the utility of mFI-5 score as an independent predictor of morbidity and mortality in patients who underwent THA or hemiarthroplasty for femoral neck fracture.

METHODS

The American College of Surgeons National Surgical Quality Improvement database was queried for all patients with femoral neck fractures treated with THA or hemiarthroplasty between 2006 and 2020. A multivariate logistic regression analysis was done using mFI-5 as a predictor while controlling for baseline demographic and clinical variables.

RESULTS

In total, 45,185 patients (hemiarthroplasty: 37,645; THA: 7,540) were identified. For hemiarthroplasty patients, the mFI-5 strongly predicted risk of any complication (OR, 1.1; 95% CI, 1.1 to 1.2; P < 0.001), bleeding (OR, 1.2; 95% CI, 1.1 to 1.3; P < 0.001), and readmission (OR, 1.2; 95% CI, 1.1 to 1.3; P < 0.001). For THA patients, the mFI-5 was a strong predictor of any complication (OR, 1.2; 95% CI, 1.0 to 1.3; P = 0.023), pneumonia (OR, 1.4; 95% CI, 1.0 to 2.0; P = 0.047), and readmission (OR, 1.3; 95% CI, 1.1 to 1.6; P = 0.004).

DISCUSSION

The mFI-5 is an independent predictor of morbidity and complications after hemiarthroplasty and THA for femoral neck fracture. Importantly, readmission risk was predicted by the mFI-5. The mFI-5 may present a valuable clinical tool for assessment of high-risk patients who might require additional resources and specialized care after femoral neck fracture.

Addition of gentamicin for antibiotic prophylaxis in hip hemiarthroplasty does not decrease the rate of surgical site infection

BACKGROUND

The addition of Gram-negative coverage to antibiotic prophylaxis protocols prior to elective total hip arthroplasty (THA) has been reported to reduce periprosthetic joint infection (PJI). However, it is unknown whether adding a Gram-negative-targeted antibiotic agent improves outcomes in the trauma population. This study aimed to investigate whether the addition of a single, pre-operative dose of Gentamicin is associated with lower rates of PJI in patients undergoing hemiarthroplasty (HA) as treatment for a hip fracture.

METHODS

We retrospectively reviewed cases of patients who underwent HA as treatment for a hip fracture from January 2011 to January 2022, and had a minimum 1-year of follow-up. Patients were divided into two groups based on the antibiotic prophylaxis they received during surgery: cefazolin (control group) or cefazolin with addition of Gentamicin (case group). The primary outcome was the rate of surgical site infections (SSI), and secondary outcomes included rates of prosthetic joint infection (PJI) and superficial SSIs.

RESULTS

The final study population consisted of 1521 patients. 336 patients (22.1%) were in the case group and 1185 (77.9%) patients were in the control group. Rates of SSI were comparable between the groups (3.8% for the case group vs. 2.8% in the control group, p = 0.34). This held true for both PJIs (3.5 vs. 2.5%, p = 0.3) and superficial SSIs (0.29 vs. 0.33%, p = 0.91). The distribution of the causing pathogen was similar between the groups (p = 0.84). Gentamicin susceptibility rates of the Gram-negative bacteria associated with PJI were similar between the cohorts (p = 0.51).

CONCLUSIONS

The addition of a single, pre-operative dose of Gentamicin to the antibiotic prophylaxis protocol of patients undergoing HA as treatment for a hip fracture was not associated with lower rates of SSI, PJI or superficial SSI. The findings of this study indicate that the prophylactic benefits of Gentamicin may not apply to HA as they do to THA.

[Acute postoperative infections after dual head arthroplasty in geriatric patients]

Acute periprosthetic joint infections (PJI) after dual head arthroplasty represent a major challenge with a 1-year mortality rate up to 50% in the mostly multimorbid geriatric patient collective. Due to the limited possibilities of preoperative patient optimization, infection rates of up to 9% have been reported, which is significantly higher than in elective arthroplasty. A therapeutic gold standard has not yet been established due to the heterogeneous study situation and the lack of prospective randomized studies. The most promising therapeutic option currently appears to be a single-stage stem replacement in combination with implantation of a cup component (conversion to total hip arthroplasty, infection eradication in up to 100%). An approach of débridement, antibiotics, implant retention (DAIR) alone shows significantly poorer success rates (16-82%). Surgical treatment should always be followed by antibiotic treatment with a total duration of 12 weeks. In addition to the established perioperative antibiotic prophylaxis, the use of antibiotic-loaded bone cement seems to be superior to cementless stem fixation in preventing PJI in dual head arthroplasty.

The Safety and Efficacy of Microporous Polysaccharide Hemospheres in Terms of the Complication Rates in Total Hip Arthroplasty for Femoral Neck Fractures: A Control-Matched Retrospective Cohort

AIMS

This study aimed to assess the safety and efficacy of microporous polysaccharide hemospheres (MPSHs) in managing blood loss and reducing the risk of postoperative haematoma and early periprosthetic joint infection (PJI) following total hip arthroplasty (THA) for femoral neck fracture (FNF), in the context of the existing treatment challenges.

METHODS

A control-matched retrospective analysis of 163 patients undergoing unilateral primary THA for displaced FNF between 2020 and 2023 was performed. The study group consisted of 74 patients who received MPSH administered intraoperatively. The control group consisted of 89 patients who received no topical haemostatics. One-to-one case-control matching between groups was performed. The primary outcome was a perioperative change in the haematologic values (haemoglobin, red blood cell count, haematocrit, platelet concentration) and transfusion rate. The secondary outcomes were the incidence of postoperative local haematoma formation, prolonged wound secretion, surgical site infection (SSI), and PJI within 3 months of surgery.

RESULTS

Our analysis found no statistically significant differences in the haematologic parameters between the control and study cohorts. The changes in the haemoglobin concentration were not significant between the control group (3.18 ± 1.0 g/dL) and the treatment group (2.87 ± 1.15 g/dL) (p = 0.3). There were no significant differences (p = 0.24) in the haematocrit and red blood cell concentration (p = 0.15). The platelet levels did not significantly differ (p = 0.12) between the groups. Additionally, we found no significant discrepancy in the incidence of early PJI or blood transfusion rates between the groups. No adverse effects following MPSH use were recorded in the study group.

CONCLUSIONS

Routine use of MPSH in THA for FNF management appears to be safe, with no observed adverse events related to Arista® use. Although there was a tendency towards reduced blood loss in the Arista® AH group, MPSH did not significantly impact bleeding complications, local haematoma formation, or subsequent PJI.

Predictors of mortality in periprosthetic fractures of the hip: Results from the national PPF study

INTRODUCTION

Periprosthetic fractures (PPFs) around the hip joint are increasing in prevalence. In this collaborative study, we aimed to investigate the impact of patient demographics, fracture characteristics, and modes of management on in-hospital mortality of PPFs involving the hip.

METHODS

Using a multi-centre cohort study design, we retrospectively identified adults presenting with a PPF around the hip over a 10-year period. Univariate and multivariable logistic regression analyses were performed to study the independent correlation between patient, fracture, and treatment factors on mortality.

RESULTS

A total of 1,109 patients were included. The in-hospital mortality rate was 5.3%. Multivariable analyses suggested that age, male sex, abbreviated mental test score (AMTS), pneumonia, renal failure, history of peripheral vascular disease (PVD) and deep surgical site infection were each independently associated with mortality. Each yearly increase in age independently correlates with a 7% increase in mortality (OR 1.07, p=0.019). The odds of mortality was 2.99 times higher for patients diagnosed with pneumonia during their hospital stay [OR 2.99 (95% CI 1.07-8.37) p=0.037], and 7.25 times higher for patients that developed renal failure during their stay [OR 7.25 (95% CI 1.85-28.47) p=0.005]. Patients with history of PVD have a six-fold greater mortality risk (OR 6.06, p=0.003). Mode of treatment was not a significant predictor of mortality.

CONCLUSION

The in-hospital mortality rate of PPFs around the hip exceeds 5%. The fracture subtype and mode of management are not independent predictors of mortality, while patient factors such as age, AMTS, history of PVD, pneumonia, and renal failure can independently predict mortality. Peri-operative optimisation of modifiable risk factors such as lung and kidney function in patients with PPFs around the hip during their hospital stay is of utmost importance.