Long-term Mortality After Revision THA

Re-revision and mortality rate following revision total hip arthroplasty for infection

Aims

This study compares the re-revision rate and mortality following septic and aseptic revision hip arthroplasty (rTHA) in registry data, and compares the outcomes to previously reported data.

Methods

This is an observational cohort study using data from the German Arthroplasty Registry (EPRD). A total of 17,842 rTHAs were included, and the rates and cumulative incidence of hip re-revision and mortality following septic and aseptic rTHA were analyzed with seven-year follow-up. The Kaplan-Meier estimates were used to determine the re-revision rate and cumulative probability of mortality following rTHA.

Results

The re-revision rate within one year after septic rTHA was 30%, and after seven years was 34%. The cumulative mortality within the first year after septic rTHA was 14%, and within seven years was 40%. After multiple previous hip revisions, the re-revision rate rose to over 40% in septic rTHA. The first six months were identified as the most critical period for the re-revision for septic rTHA.

Conclusion

The risk re-revision and reinfection after septic rTHA was almost four times higher, as recorded in the ERPD, when compared to previous meta-analysis. We conclude that it is currently not possible to assume the data from single studies and meta-analysis reflects the outcomes in the 'real world'. Data presented in meta-analyses and from specialist single-centre studies do not reflect the generality of outcomes as recorded in the ERPD. The highest re-revision rates and mortality are seen in the first six months postoperatively. The optimization of perioperative care through the development of a network of high-volume specialist hospitals is likely to lead to improved outcomes for patients undergoing rTHA, especially if associated with infection.

Periprosthetic joint infections in patients with rheumatoid arthritis are associated with higher complication and mortality rates

INTRODUCTION

Periprosthetic joint infection (PJI) remains the most devasting complication after total joint arthroplasty (TJA). There has been a significant focus on this topic in recently-published medical literature. However, relatively little has been published about PJI in patients with rheumatoid arthritis (RA), which are often physiologically frail and immunocompromised. A better understanding of PJI in this patient population is therefore crucial. The main aims of this paper are to (1) report complication and mortality rates in a cohort of PJI-RA patients; and (2) clinically characterize them.

METHODS

Medical and surgical records of all RA PJI patients treated surgically from 2003 to 2020 were retrospectively reviewed. Medical history, physical examination, reactive protein (CRP) level, procalcitonin, white blood cell (WBC) count, joint aspiration results, and cultures were used to determine PJI.

RESULTS

54PJIs, 49 of them chronic, were treated in 53RA patients. Mean patient age was 65 yrs. (range = 32-88); 33females and 20 males (one bilateral hip). The overall mortality rate was 18.9%(n = 10), with five deaths directly attributed to PJI. Staphylococci accounted for 34 infections (63%), while 11(20.4%) had multiorganism infections and six culture-negative PJI. At the end of treatment 79.6%(n = 43) still had an implanted TJR, 7.4% (n = 4) had spacers, 5.6%(n = 3) had undergone resection arthroplasty, 3.7%(n = 2) arthrodesis, and one each amputation and exarticulation.

CONCLUSIONS

Mortality and specially complication rates were (are) high in this RA patients group presenting PJI. Delays to diagnosis and treatment may explain some of these poor outcomes.

LEVEL OF EVIDENCE

A cohort level III retrospective study.

Biomarkers to discriminate between aseptic loosened and stable total hip or knee arthroplasties: a systematic review

Background

Loosening is a major cause for failure of total hip and total knee arthroplasties (THAs/TKAs). Preemptive diagnostics of asymptomatic loosening could open strategies to prevent gross loosening. A multitude of biomarkers may discriminate between loosened and stable implants, but it is unknown which have the best performance. The present systematic review aimed to assess which biomarkers have shown the most promising results in discriminating between stable and aseptic loosened THAs and TKAs.

Methods

PubMed, Embase, Web of Science, Cochrane Library, and Academic Search Premier were systematically searched up to January 2020 for studies including THA/TKA and biomarkers to assess loosening. Two reviewers independently screened records, extracted data, and assessed the risk of bias using the ICROMS tool to classify the quality of the studies.

Results

Twenty-eight (three high-quality) studies were included, reporting on a median of 48 patients (interquartile range 28-69). Serum and urine markers were evaluated in 22 and 10 studies, respectively. Tumor necrosis factor α and osteocalcin were significantly higher in loosened compared with stable implants. Urinary N-terminal telopeptide had significantly elevated levels in loosened prostheses.

Conclusion

Several serum and urine markers were promising in discriminating between loosened and stable implants. We recommend future studies to evaluate these biomarkers in a longitudinal fashion to assess whether progression of loosening is associated with a change in these biomarkers. In particular, high-quality studies assessing the usability of these biomarkers are needed.

Decreasing trend of inpatient mortality rates of aseptic versus septic revision total hip arthroplasty: an analysis of 681,034 cases

BACKGROUND

While most revision total hip arthroplasties (rTHAs) are for aseptic loosening/instability, infection accounts for approximately 16%. The purpose of this study was to: (1) quantify mortality rates of aseptic versus septic rTHA; (2) determine if mortality rates have changed over the past 20 years; and (3) identify associated preoperative risk factors, focusing on the utility/validity of the Elixhauser comorbidity index (ECI).

METHODS

ICD-9/ICD-10 codes were used to identify patients undergoing rTHA in the National Inpatient Sample database between 1998 and 2017. A total of 681,034 cases (576,143 aseptic THA and 104,891 septic THA) were identified. For each patient, demographic variables including age, sex, race, insurance type, ECI, and inhospital mortality were gathered. A logistic regression model was constructed to assess risk of inhospital mortality.

RESULTS

From 1998 to 2017, inpatient mortality rates of aseptic and septic rTHA decreased from 0.83 to 0.45%, and from 2.58 to 1.24%, respectively. Septic rTHA was independently associated with higher odds of mortality relative to aseptic (odds ratio (OR): 2.305, 95% confidence interval (CI): (2.014, 2.638), p < 0.0001). Increased ECI was associated with higher odds of mortality at both medium (OR: 5.147, 95% CI: (4.433,5.977), p < 0.0001) and high index scores (OR: 13.714, 95% CI: (11.519,16.326), p < 0.0001).

CONCLUSIONS

Mortality rates for both aseptic and septic rTHA have been declining over the past 20 years, potentially due to patient selection guidelines and advances in medical management. Our study confirms that the ECI is independently associated with increased inpatient mortality.

Management of Acetabular Bone Loss in Hip Revision Arthroplasty: Case Series Presentation

Considering the increase in life expectancy in the general population and the need for a more active lifestyle, total hip arthroplasty has become an absolutely necessary surgical intervention to maintain these desired results. Along with the evolution of medicine and the increase in the quality and performance of the materials used to make prostheses, the number of patients who benefit from total hip replacement is constantly increasing, and proportionally, the number of patients who will require revision arthroplasty is increasing. Before discussing the need for hip arthroplasty revision, it is necessary to carry out a rigorous clinical and imaging examination for differential diagnosis with other pathologies such as low back pain, the presence of bone or soft tissue tumors, arterial occlusions and claudication, or other systemic diseases. One of the biggest challenges for the orthopedic surgeon in planning a hip revision is the compensation of the remaining acetabular bone defect, either as a result of the osteolysis process or following the process of removing the acetabular component, which in some cases can lead to severe bone loss that is difficult to anticipate in the preoperative planning. In this paper, we will present the short-term results of the use of reinforcement cages fixed with screws and cemented retentive acetabular cups in the case of hip revisions with extensive bone loss. The discussions that derive from the presented series of cases are related to the use of reinforcement cages, which are based on the principle of primary stability obtained with the help of screw fixation but whose risk of osteolysis and implant fixation damage is greater than in the case of implants that also associate biological integration at bone level. The use of reinforcement cages together with the retentive acetabular cup in the case of elderly patients with associated comorbidities, a moderate level of physical activity, and severe muscle insufficiency at the hip level as a result of not using the affected pelvic limb is still a viable solution that allows the patient to walk immediately after the surgery, avoiding the risk of dislocation (especially in patients who use the posterolateral approach) and avoiding morbidity induced by prolonged bed rest.

Revision total hip arthroplasty for periprosthetic fracture: epidemiology, outcomes, and factors associated with success

The aging population and the increasing number of patients with primary total hip arthroplasties (THA) has equated to an increased incidence of periprosthetic fractures (PPF) of the hip. These injuries are a significant source of patient morbidity and mortality, placing a financial burden on healthcare systems worldwide. As the volume of PPF is expected to along with the growing volume of primary and revision THA, it is important to understand the outcomes and factors associated with treatment success. The choice of procedure is in large part guided by the help of the Vancouver Classification system, which is a valid and reproducible system that classifies fractures based on several factors including site of fracture, implant stability and bone stock. PPFs account for approximately 18% of revision THA (rTHA) procedures. rTHA for PPFs is commonly indicated in Vancouver B2 and B3 fractures, to bypass a lack of metaphyseal support with diaphyseal fixation. Such revisions are technically challenging and typically require urgent treatment, with inherent difficulties in patient optimization, leading to a notable rate of post-operative complications, re-revision and mortality. This article reviews epidemiology, health economics and risk factors for PPFs. It additionally reviews outcomes associated with rTHA for PPFs including peri-operative complications, indications for re-operation, rates of re-operation and rates of mortality. Finally, it aims to identify evidence-based factors that have been associated with successful management including modifiable patient-related factors, uncemented vs. cemented stems, stem design (porous coated stems vs. fluted tapered stems), modularity, dislocation and its impact on outcomes following rTHA and strategies for managing bone loss.

Understanding the 30-day mortality burden after revision total hip arthroplasty

BACKGROUND

Revision total hip arthroplasty (THA) is a challenging procedure that burdens the healthcare system. Despite being associated with worse outcomes relative to its primary counterpart, postoperative mortality after revision THA remains ill-defined. The present study aimed to (1) establish the overall 30-day mortality rate after revision THA and (2) explore the mortality rate stratified by age, comorbidity burden, and aseptic versus septic failure.

METHODS

The American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) database was retrospectively reviewed for all patients who underwent revision THA from 2011 to 2019. A total of 23,501 patients were identified and grouped into mortality (n = 161) and mortality-free (n = 23,340) cohorts. Patient demographics, comorbidities, and aseptic/septic failure were evaluated.

RESULTS

The overall 30-day mortality was 0.69%. The mortality rate by age group (normalised per 1000 patients) was 0 (18-39 years [Y]), 0.67 (40-49 Y), 1.10 (50-59 Y), 2.58 (60-69 Y), 6.15 (70-79 Y) 19.32 (80-89 Y), and 58.22 (90+Y) (p < 0.001). The mortality rate by ASA classification (normalised per 1000 patients) was 0 (ASA I), 1.47 (ASA II), 6.94 (ASA III), 45.42 (ASA IV), and 200 (ASA V) (p < 0.001). The 30-day mortality rate for the septic and aseptic cohorts was 1.03% and 0.65%, respectively (p = 0.038). CCI scores (p < 0.001), diabetes (p < 0.001), systematic sepsis (p < 0.001), poor functional status (p < 0.001), BMI < 24.9 kg/m2 (p < 0.001), and dirty/infected wounds (p < 0.001) were all associated with increased mortality risk.

CONCLUSIONS

1 in 145 patients will suffer mortality during the 30 days after revision THA. PJI-related revision THA was associated with 1.5-fold increase in 30-day mortality rate compared to its aseptic counterpart. Certain patient determinants and baseline comorbidities, as measured by ASA and CCI scores, were associated with higher 30-day mortality rates. Therefore, it is imperative to identify such risk factors and implement perioperative patient optimisation pathways to mitigate the risk among vulnerable patients.

Primary and Revision Total Hip Arthroplasty in Patients With Pulmonary Hypertension: High Perioperative Mortality and Medical Complications

BACKGROUND

Perioperative medical management during total hip arthroplasty (THA) is continuously improving, allowing an increasing number of medically complex patients to undergo total joint arthroplasty. This study examined mortalities, medical complications, implant survivorships, and clinical outcomes of THA in patients who have pulmonary hypertension (HTN).

METHODS

We identified 638 patients who had pulmonary HTN and underwent 508 primary THAs and 191 revision THAs from 2000 to 2016 at a tertiary care center. Patients were followed up at regular intervals until death, revision surgery, or last clinical follow-up. Perioperative medical complications were individually reviewed. The risk of death was examined by calculating standardized mortality ratios and Cox proportional hazards regression models. Cumulative incidence analyses were used for reporting mortality, reoperation, and revision with death as a competing risk.

RESULTS

The 90-day mortality was 1.8% and 3.1% for primary and revision THAs, respectively. The risk of death was approximately two-fold higher compared to primary (hazard ratio 2.69) and revision (hazard ratio 2.04) THA patients who did not have pulmonary HTN. Rate of medical complications within 90 days from surgery were 6.2% and 13.1% in primary and revision THAs, respectively. The 10-year cumulative incidence of any revision was 9% and 14% following primaries and revisions, respectively.

CONCLUSION

Patients who had pulmonary HTN undergoing primary and revision THAs had an increased risk of death and experienced a high rate of medical complications within 90 days of surgery. Counseling of risks, medical optimization, and referral to medical centers expert at managing complex medical problems should be considered.

LEVEL OF EVIDENCE

Level IV.

Mortality and re-revision following single-stage and two-stage revision surgery for the management of infected primary hip arthroplasty in England and Wales

We compared the risks of re-revision and mortality between two-stage and single-stage revision surgeries among patients with infected primary hip arthroplasty. Patients with a periprosthetic joint infection (PJI) of their primary arthroplasty revised with single-stage or two-stage procedure in England and Wales between 2003 and 2014 were identified from the National Joint Registry. We used Poisson regression with restricted cubic splines to compute hazard ratios (HRs) at different postoperative periods. The total number of revisions and re-revisions undergone by patients was compared between the two strategies. In total, 535 primary hip arthroplasties were revised with single-stage procedure (1,525 person-years) and 1,605 with two-stage procedure (5,885 person-years). All-cause re-revision was higher following single-stage revision, especially in the first three months (HR at 3 months = 1.98 (95% confidence interval (CI) 1.14 to 3.43), p = 0.009). The risks were comparable thereafter. Re-revision for PJI was higher in the first three postoperative months for single-stage revision and waned with time (HR at 3 months = 1.81 (95% CI 1.22 to 2.68), p = 0.003; HR at 6 months = 1.25 (95% CI 0.71 to 2.21), p = 0.441; HR at 12 months = 0.94 (95% CI 0.54 to 1.63), p = 0.819). Patients initially managed with a single-stage revision received fewer revision operations (mean 1.3 (SD 0.7) vs 2.2 (SD 0.6), p < 0.001). Mortality rates were comparable between these two procedures (29/10,000 person-years vs 33/10,000). The risk of unplanned re-revision was lower following two-stage revision, but only in the early postoperative period. The lower overall number of revision procedures associated with a single-stage revision strategy and the equivalent mortality rates to two-stage revision are reassuring. With appropriate counselling, single-stage revision is a viable option for the treatment of hip PJI.

Registry Data Show Complication Rates and Cost in Revision Hip Arthroplasty

INTRODUCTION

Revision THA (rTHA) places a burden on patients, surgeons, and health care systems because outcomes and costs are less predictable than primary THA. The purposes of this study were to define indications and treatments for rTHA, quantify risk for readmissions and evaluate the economic impacts of rTHA in a hospital system.

METHODS

The arthroplasty database of a hospital system was queried to generate a retrospective cohort of 793 rTHA procedures, performed on 518 patients, from 2017 to 2019 at 27 hospitals. Surgeons performed chart reviews to classify indication and revision procedure. Demographics, lengths of stay (LOS), discharge dispositions, and readmission data were collected. Analyses of direct costs were performed and categorized by revision type.

RESULTS

46.3% of patients presented for infection. Patients presenting for infection were 5.6 times more likely to have repeat rTHA than aseptic patients. Septic cases (4.3 days) had longer LOS than aseptic ones (2.4) (P < 0.0001). 31% of patients discharged to a skilled nursing facility (SNF). Direct costs were greatest for a two-stage exchange ($37,642), and lowest for liner revision ($8,979). Septic revisions ($17,696) cost more than aseptic revisions ($11,204) (P< 0.0001). The 90-day readmission rate was 21.8%. Septic revisions had more readmissions (13.5%) than aseptic revisions (8.3%).

CONCLUSIONS

Hip revisions, especially for infection, have an increased risk profile and create a major economic impact on hospital systems. Surgeons may use these data to counsel patients on risks of rTHA and advocate for improved reimbursement for the care of revision patients.

The Dopamine D1 Receptor Attenuates Titanium Particle-Induced Inhibition of Osteogenesis by Activating the Wnt Signaling Pathway

Periprosthetic osteolysis (PPO), caused by wear particles, has become a major cause of joint replacement failure. Secondary surgery after joint replacement poses a serious threat to public health worldwide. Therefore, determining how to effectively inhibit wear particle-induced PPO has become an urgent issue. Recently, the interaction between osteogenic inhibition and wear particles at the biological interface of the implant has been found to be an important factor in the pathological process. Previous studies have found that the central nervous system plays an important role in the regulation of bone formation and bone remodeling. Dopamine (DA), an important catecholamine neurotransmitter, plays an integral role in the physiological and pathological processes of various tissues through its corresponding receptors. Our current study found that upregulation of dopamine first receptors could be achieved by activating the Wnt/β-catenin pathway, improving osteogenesis in vivo and in vitro, and significantly reducing the inhibition of titanium particle-induced osteogenesis. Overall, these findings suggest that dopamine first receptor (D1R) may be a plausible target to promote osteoblast function and resist wear particle-induced PPO.

Patient-reported outcome measures, complication rates, and re-revision rates are not associated with the indication for revision total hip arthroplasty : a prospective evaluation of 647 consecutive patients

AIMS

The aim of this study was to explore the relationship between reason for revision total hip arthroplasty (rTHA) and outcomes in terms of patient-reported outcome measures (PROMs).

METHODS

We reviewed a prospective cohort of 647 patients undergoing full or partial rTHA at a single high-volume centre with a minimum of two years' follow-up. The reasons for revision were classified as: infection; aseptic loosening; dislocation; structural failure; and painful THA for other reasons. PROMs (modified Oxford Hip Score (mOHS), EuroQol five-dimension three-level health questionnaire (EQ-5D-3L) score, and visual analogue scales for pain during rest and activity), complication rates, and failure rates were compared among the groups.

RESULTS

The indication for revision influenced PROMs improvement over time. This finding mainly reflected preoperative differences between the groups, but diminished between the first and second postoperative years. Preoperatively, patients revised due to infection and aseptic loosening had a lower mOHS than patients with other indications for revision. Pain scores at baseline were highest in patients being revised for dislocation. Infection and aseptic loosening groups showed marked changes over time in both mOHS and EQ-5D-3L. Overall complications and re-revision rates were 35.4% and 9.7% respectively, with no differences between the groups (p = 0.351 and p = 0.470, respectively).

CONCLUSION

Good outcomes were generally obtained regardless of the reason for revision, with patients having the poorest preoperative scores exhibiting the greatest improvement in PROMs. Furthermore, overall complication and reoperation rates were in line with previous reports and did not differ between different indications for rTHA. Cite this article: Bone Joint J 2022;104-B(7):859-866.

Periprosthetic femoral fractures in Total Hip Arthroplasty (THA): a comparison between osteosynthesis and revision in a retrospective cohort study

Background

Periprosthetic femoral fractures are challenging complications of hip arthroplasty. They are supposed to be a rare complication, but their incidence is rapidly increasing. Surgical treatment aims to achieve early mobilization and avoid the complications of prolonged bed rest. Aim of this study is to evaluate the clinical outcomes of surgical treatment comparing two surgical approaches: revision arthroplasty (RA) versus open reduction and internal fixation (ORIF).

Methods

Authors retrospectively reviewed a series of 117 patients with total hip arthroplasty treated for periprosthetic femur fractures in the period between January 2013 and March 2018 at a single tertiary referral center. Of these, 70 patients satisfied strict inclusion criteria. Patients were classified according to the Unified Classification System (UCS) and distributed in two groups according to surgical treatment. Clinical outcomes were assessed using the Oxford Hip recorded preoperatively and post operatively, Barthel Score, CIRS score (Cumulative illness rating scale), type of fracture and post-operative complications with a minimum follow up of 1 year.

Results

Nominal univariate statistical analysis revealed significant differences between the post and pre-operative Oxford Hip Score (Δ Oxford) and the surgical treatment (p = 0.008) and CIRS score (p = 0.048). Moreover, we observed a significant relationship between type of treatment and type of fracture (p = 0.0001). Multivariate analyses revealed that CIRS score was independently associated with Oxford Score improvement after surgery (p = 0.024).

Conclusions

Data from this case series confirmed that surgical treatment was correlated to type of fracture, according to UCS classification. Patients treated by RA had a better functional outcome than patients treated with ORIF, but these results are strongly influenced from the patients’ age, Barthel index and CIRS score. Also, authors found a correlation between functional outcome and comorbidities evaluated by CIRS score. Based on these data we suggest a multimodal approach to these patients, like those used for proximal femoral fractures.

In-Hospital Mortality Is Associated With Low-Volume Hip Revision Centers After Septic Revision Total Hip Arthroplasty

Revision total hip arthroplasty (rTHA) after septic failure is associated with higher morbidity and mortality compared with aseptic revisions. The goals of this study were to characterize (1) the in-hospital mortality rate for patients with septic rTHA, (2) the effect of hospital hip revision surgery volume (HRV) on mortality after septic rTHA, and (3) the independent risk factors associated with in-hospital mortality rates after rTHA with 2-year follow-up. The authors analyzed the Healthcare Cost and Utilization Project State Inpatient Databases of New York and Florida to identify cases of septic rTHA from 2007 to 2012 with International Classification of Diseases, Ninth Revision, codes. The authors included patients with (1) no history of THA for 2 years before the index admission and (2) 2 years of follow-up. Groups with primary THA and aseptic rTHA were identified as control groups. Logistic regression was used to evaluate independent associations. Of 3057 patients with septic rTHA, 5.2% (n=160) had in-hospital mortality vs 2.9% of those with primary THA (n=3525, P=.0001) and 2.1% of those with aseptic rTHA (n=252, P=.0001). Octogenarian status, medium-risk Elixhauser comorbidity score, and high-risk Elixhauser comorbidity score were independent risk factors for mortality (adjusted odds ratio [AOR]=1.587, 95% CI=1.103-2.282, P=.0128; AOR=2.439, 95% CI=1.680-3.541, P<.0001; and AOR=6.367, 95% CI=4.134-9.804, P<.0001, respectively). Undergoing rTHA in a high-HRV hospital was associated with lower odds of in-hospital mortality (AOR=0.539, 95% CI=0.332-0.877, P=.0127). Receiving care in a low-HRV hospital increased the risk of 2-year postoperative patient mortality. Similarly, older age and a higher comorbidity burden were independently associated with increased 2-year postoperative mortality. [Orthopedics. 2022;45(1):57-63.].

The Outcomes of Cemented Femoral Revisions for Periprosthetic Femoral Fractures in the Elderly: Comparison with Cementless Stems

Introduction

The present study compares the outcome of the long cemented stem and the revision uncemented stem used in periprosthetic femoral fractures. We propose that the revision with a long stem cemented prosthesis does not compromise fracture healing.

Patients and Methods

A consecutive series of 37 patients, operated between 2010 and 2017, were enrolled in a retrospective analysis. A long cemented stem was implanted in 21 patients (study group; age at operation: 63 to 89 years). A distally tapered fluted uncemented stem was used in 16 patients (control group; age at operation: 35 to 77 years). The clinical outcome was evaluated with Merle d'Aubigné and Postel scoring system. Standard radiographs were taken before surgery, at 3, 6, and 12 months postoperatively, and last follow-up. Any and all complications during the follow-up period were recorded.

Results

Although a significant difference (P = 0.006) was observed in the post-operative Merle d´Aubigné score over the 12-month follow-up period, no significant difference (P = 0.066) was found in the post-operative pain score between the study and control groups. Periodic radiographic assessments showed the disappearance of radiolucent lines and the diaphyseal part of the fracture was healed in all 34 followed-up cases during the first annual follow-up. Early surgical complications were seen in both groups, the medical complications were observed only in the study group.

Conclusion

Based on our results, periprosthetic fractures of the femur after a total hip arthroplasty were associated with significant morbidity and increased mortality in elderly patients. Revision with a long-stem cemented prosthesis provided early pain-free weight-bearing without compromising the healing of femoral fractures in elderly patients with osteoporotic bone, altered mobility, poor balance, and reduced cognitive capacity.

Renal Toxicity Associated With Resection and Spacer Insertion for Chronic Hip PJI

BACKGROUND

Two-stage exchange arthroplasty with high-dose antibiotic-loaded bone cement spacer and intravenous (IV) antibiotics is the most common method of managing infected total hip arthroplasties. However, the contemporary incidence, risk factors, and outcomes of acute kidney injuries (AKIs) in this cohort are unknown.

METHODS

We identified 227 patients treated with 256 antibiotic-loaded bone cement spacers after resection of an infected primary total hip arthroplasty between 2000 and 2017. Mean age was 65 years, mean body mass index was 30 mg/kg², 55% were men, and 16% had pre-existing chronic kidney disease (CKD). Spacers were in situ for a mean of 15 weeks, concomitantly associated with IV or oral antibiotics for a mean of 6 weeks. AKI was defined as a creatinine ≥1.5X baseline or ≥0.3 mg/dL. Mean follow-up was 8 years.

RESULTS

AKI occurred in 13 patients without pre-existing CKD (7%) vs 10 patients with CKD (28%; OR 5; P = .0001). None required acute dialysis. Postoperative fluid depletion (β = 0.31; P = .0001), ICU requirement (β = 0.40; P = .0001), and acute atrial fibrillation (β = 0.43; P = .0001) were independent predictors for AKI in patients without pre-existing CKD. Duration of in situ spacer, mean antibiotic dose in cement, use of amphotericin B, and type of IV antibiotics were not significant risk factors. At last follow-up, 8 AKIs progressed to CKD, with one receiving dialysis 7 years later.

CONCLUSION

AKIs occurred in 7% of patients with normal renal function, with 5-fold greater risk in those with CKD, and 4% did develop CKD. Importantly, causes of acute renal blood flow impairment were independent predictors for AKI.

LEVEL OF EVIDENCE

Level III, comparative study.

Revisions for Periprosthetic Hip Infections Do Not Fail More Than Revisions for Aseptic Loosening, but Mortality is Higher

BACKGROUND

The influence of the reasons for revision on the outcomes of revision hip arthroplasties is controversial and poorly described. A registry study was designed to compare the revision hips performed for periprosthetic hip infection (PHI) to the revision hips performed for aseptic loosening. The aims of this study were the long-term assessment and comparison of survival rates, reasons for rerevisions, and mortality rates between these two cohorts.

METHODS

By using an arthroplasty registry, revision hips were stratified according to the reasons for revision (aseptic loosening and PHI). Preoperative and intraoperative, demographic and implant-related features were recorded. Survival rates, reasons for revision and mortality rates were assessed and compared.

RESULTS

The two cohorts were homogenous for preoperative and intraoperative parameters, apart from age at revision, time elapsed between THA and revision, bearing surfaces, and head size. At 10 years, the survival rates were similar between the two groups (P = .51). Half of the rerevisions occurred in the first two years in both the groups. The reasons for rerevision were similar: when rerevision for infection was adopted as an end point, the two cohorts showed nonsignificant differences. The mortality rate was statistically higher in the PHI cohort (P .0015, hazard ratio adjusted for age and gender: 1.42).

CONCLUSION

Aseptic and septic revisions achieved similar outcomes at long-terms, rerevisions tended to fail for the same reason for revision. The mortality rate was significantly higher in the septic cohort. These findings are useful to modify and tune the preoperative, intraoperative, and postoperative managements of revisions.

Automated Detection of Periprosthetic Joint Infections and Data Elements Using Natural Language Processing

BACKGROUND

Periprosthetic joint infection (PJI) data elements are contained in both structured and unstructured documents in electronic health records and require manual data collection. The goal of this study is to develop a natural language processing (NLP) algorithm to replicate manual chart review for PJI data elements.

METHODS

PJI was identified among all total joint arthroplasty (TJA) procedures performed at a single academic institution between 2000 and 2017. Data elements that comprise the Musculoskeletal Infection Society (MSIS) criteria were manually extracted and used as the gold standard for validation. A training sample of 1208 TJA surgeries (170 PJI cases) was randomly selected to develop the prototype NLP algorithms and an additional 1179 surgeries (150 PJI cases) were randomly selected as the test sample. The algorithms were applied to all consultation notes, operative notes, pathology reports, and microbiology reports to predict the correct status of PJI based on MSIS criteria.

RESULTS

The algorithm, which identified patients with PJI based on MSIS criteria, achieved an f1-score (harmonic mean of precision and recall) of 0.911. Algorithm performance in extracting the presence of sinus tract, purulence, pathologic documentation of inflammation, and growth of cultured organisms from the involved TJA achieved f1-scores that ranged from 0.771 to 0.982, sensitivity that ranged from 0.730 to 1.000, and specificity that ranged from 0.947 to 1.000.

CONCLUSION

NLP-enabled algorithms have the potential to automate data collection for PJI diagnostic elements, which could directly improve patient care and augment cohort surveillance and research efforts. Further validation is needed in other hospital settings.

LEVEL OF EVIDENCE

Level III, Diagnostic.

High mortality following revision hip arthroplasty for periprosthetic femoral fracture

AIMS

To determine mortality risk after first revision total hip arthroplasty (THA) for periprosthetic femoral fracture (PFF), and to compare this to mortality risk after primary and first revision THA for other common indications.

METHODS

The study cohort consisted of THAs recorded in the National Joint Registry between 2003 and 2015, linked to national mortality data. First revision THAs for PFF, infection, dislocation, and aseptic loosening were identified. We used a flexible parametric model to estimate the cumulative incidence function of death at 90 days, one year, and five years following first revision THA and primary THA, in the presence of further revision as a competing risk. Analysis covariates were age, sex, and American Society of Anesthesiologists (ASA) grade.

RESULTS

A total of 675,078 primary and 74,223 first revision THAs were included (of which 6,131 were performed for PFF). Following revision for PFF, mortality ranged from 9% at 90 days, 21% at one year, and 60% at five years in the highest risk group (males, ≥ 75 years, ASA ≥ 3) to 0.6%, 1.4%, and 5.5%, respectively, for the lowest risk group (females, < 75 years, ASA ≤ 2). Mortality was greater in all groups following first revision THA for PFF than for primary THA. Compared to mortality risk after first revision THA for infection, dislocation, or aseptic loosening, revision for PFF was associated with higher five-year mortality in all groups except males < 75 years with an ASA ≤ 2.

CONCLUSION

Mortality risk after revision THA for PFF is high, reaching 60% at five years in the highest risk patient group. In comparison to other common indications for revision, PFF demonstrated the highest overall risk of mortality at five years. These estimates can be used in the surgical decision-making process and when counselling patients and carers regarding surgical risk. Cite this article: Bone Joint J 2020;102-B(12):1670-1674.

The Lawrence D. Dorr Surgical Techniques & Technologies Award: Aseptic Reoperations Within One Year of Primary Total Hip Arthroplasty Markedly Increase the Risk of Later Periprosthetic Joint Infection

BACKGROUND

Despite the success of primary total hip arthroplasties (THAs), some patients will require an aseptic reoperation within 1 year of the index THA. The goal of this study is to evaluate the risk of subsequent periprosthetic joint infection (PJI) in patients undergoing an aseptic reoperation within 1 year of a primary THA.

METHODS

A retrospective review utilizing our institutional joint registry identified 211 primary THAs requiring aseptic reoperation within 1 year following index arthroplasty. A control group of 15,357 primary THAs not requiring reoperation within 1 year was identified. Patients were divided into groups based on time from primary THA to reoperation: (1) within 90 days (n = 112 THAs; 40% for dislocation, 34% for periprosthetic fracture) or (2) 91-365 days (n = 99 THAs; 37% for dislocation, 29% for periprosthetic fracture). Mean follow-up was 7 years.

RESULTS

Patients undergoing an aseptic reoperation within 90 days had a PJI rate of 4.8% at 2 years, while the 91-365 day group had a PJI rate of 3.2% at 2 years. The control group had a PJI rate of 0.2% at 2 years. Employing a multivariate analysis, reoperation within 90 days of index arthroplasty had an elevated risk of PJI (hazard ratio 8, P < .001) as did a reoperation between 91 and 365 days (hazard ratio 13, P < .001).

CONCLUSION

Aseptic reoperations within 1 year following primary THA resulted in an 8- to 13-fold increased risk of subsequent PJI. The risk was similar whether the aseptic reoperation was early (within 90 days) or later (91-365 days).

LEVEL OF EVIDENCE

Level III (Prognostic).

ZBTB20-mediated titanium particle-induced peri-implant osteolysis by promoting macrophage inflammatory responses

Aseptic loosening (AL) caused by wear particles released from implant surfaces is one of the main causes for the failure of artificial joints, which is initiated by macrophage inflammatory responses. Emerging evidence suggests that the member of a broad-complex, tramtrack, bric-a-brac/poxvirus and zinc finger (BTB/POZ) family as well as zinc finger and BTB domain-containing protein 20 (ZBTB20) can inhibit IκBα gene transcription, promote NF-κB activation, and initiate innate immune responses. The molecular mechanism(s) by which ZBTB20 contributes to titanium particle (TiP)-induced macrophage inflammatory responses and osteolysis has not been fully elucidated. Here, we showed that ZBTB20 increased either in the AL group's synovial membranes or in TiP-stimulated bone-marrow-derived macrophages (BMDMs) as compared to that in the control groups. Moreover, the knockdown of ZBTB20 led to the inhibition of proinflammatory factors induced by TiPs in BMDMs, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interferon-β (IFN-β). Here, we also reported that the knockdown of ZBTB20 suppressed TiP-induced NF-κB activation and M1 polarization as well as stabilized the trans Golgi network (TGN) in BMDMs. The dual-luciferase reporter assay identified the binding between the IκBα promoter and ZBTB20, and IκBα knockdown could rescue the antiinflammatory effects induced by the ZBTB20 knockdown in BMDMs. Finally, we found that sh-ZBTB20 lentivirus injection could reduce TiP-induced osteolysis in mouse calvaria, inhibiting TiP-induced proinflammatory factors and loss of bone volume/total volume (BV/TV) as well as bone mineral density (BMD). These results suggest that ZBTB20 positively regulated NF-κB activation and M1 polarization as well as the production of TGN-derived tubular carriers in BMDMs, playing a positive role in macrophage activation and mouse cranial osteolysis induced by TiPs. It may be a potential therapeutic target for the prevention of aseptic loosening of prostheses.

Predictors of Health-Related Quality of Life After Revision Total Hip Arthroplasty for Aseptic Loosening

BACKGROUND

Few studies have investigated the relationships between preoperative or intraoperative patient factors and postoperative quality of life (QOL) after revision total hip arthroplasty (THA). The aim of our study was to identify the predictors of QOL after revision THA for aseptic loosening.

MATERIALS AND METHODS

Fifty-one patients who underwent revision THA for aseptic loosening were included in the present study. Preoperative hip function was evaluated using the Japanese Orthopaedic Association (JOA) score. The patients' QOL after surgery was evaluated with EuroQol 5D (EQ-5D) assessment at the end of the 2-year follow-up. The patients were then divided into two groups: good QOL (score ≥ 0.6) and poor QOL (score < 0.6). Predictive factors (i.e., age, BMI, preoperative JOA score, and the degree of acetabular bone defect according to the Paprosky classification) were compared between both QOL groups. Furthermore, multiple linear regression was performed to assess independent factors affecting the QOL.

RESULTS

Significant differences between the good and poor QOL groups were identified for BMI, walking ability, and severity of acetabular bone defect (BMI: 21.5 ± 2.9 vs. 24.1 ± 4.3, P = 0.0331; walking ability: 11.5 ± 5.0 vs. 5.5 ± 4.9, P = 0.0058; acetabular bone defect: 44.4% vs. 81.0%, P = 0.0103). The walking ability independently affected the EQ-5D utility score.

CONCLUSIONS

The present study indicates that a higher BMI, lower walking ability, and more severe acetabular bone defect are predictors of lower QOL after revision THA for aseptic loosening. In particular, the walking ability was the only independent factor. Thus, surgeons should pay attention to the postoperative management of patients with these risk factors.

A growing challenge: The rise of femoral periprosthetic fractures - An 11-year observational study

INTRODUCTION

The demand for joint arthroplasty has risen as our elderly population increases and ages. With this so to has the number of patients suffering periprosthetic fractures (PPF). The aim of our study was to quantify the burden of PPF and provide an up to date reference of the epidemiology of PPF in Ireland. We also sought to assess length of stay (LOS), resource utilisation and mortality associated with this cohort of patients.

METHODS

An eleven-year retrospective observational study was conducted of a consecutive series of patients treated for a femoral PPF. Costs were obtained from activity based tariffs provided by the hospital inpatient enquiry system and mortality was confirmed using the national death events publication system.

RESULTS

Over the 11-year study period 174 procedures for a femoral PPF were performed. Mean age of patients was 77.6 years (SD 11.1 years) with 44.7% male. Median ASA grade was 3 (range 1-4) and mean LOS was 19 days. There was a 700% increase in patients undergoing surgery for a PPF over the study period. The mean cost of care was €24,413 in 2017. Thirty-day mortality was 2.9% while one-year mortality was 12.4%.

CONCLUSIONS

PPF occur in an elderly comorbid cohort of patients. Care of these patients now makes up a considerable part of the orthopaedic workload and consumes a significant portion of healthcare resources. Patients should be treated in tertiary referral centres with surgeons skilled in their management. Better access to rehabilitation is needed.

Association between patient survival following reoperation after total hip replacement and the reason for reoperation: an analysis of 9,926 patients in the Swedish Hip Arthroplasty Register

Background and purpose - The association between long-term patient survival and elective primary total hip replacement (THR) has been described extensively. The long-term survival following reoperation of THR is less well understood. We investigated the relative survival of patients undergoing reoperation following elective THR and explored an association between the indication for the reoperation and relative survival. Patients and methods - In this observational cohort study we selected the patients who received an elective primary THR and subsequent reoperations during 1999-2017 as recorded in the Swedish Hip Arthroplasty Register. The selected cohort was followed until the end of the study period, censoring or death. The indications for 1st- and eventual 2nd-time reoperations were analyzed and the relative survival ratio of the observed survival and the expected survival was determined. Results - There were 9,926 1st-time reoperations and of these 2,558 underwent further reoperations. At 5 years after the latest reoperation, relative survival following 1st-time reoperations was 0.94% (95% CI 0.93-0.96) and 0.90% (CI 0.87-0.92) following 2nd-time reoperations. At 5 years patients with a 1st-time reoperation for aseptic loosening had higher survival than expected; however, reoperations performed for periprosthetic fracture, dislocation, and infection had lower survival. Interpretation - The relative survival following 1st- and 2nd-time reoperations in elective THR patients differs by reason for reoperation. The impact of reoperation on life expectancy is more obvious for infection/dislocation and periprosthetic fracture.