Long-Term Survival of Retained Cementless Hip Stems at an Average of 13 Years After Isolated Cup Revision

The impact of retaining the femoral stem in revision total hip arthroplasty: a systematic review, meta-analysis, and meta-regression

INTRODUCTION

The management of well-fixed femoral stems in revision total hip arthroplasty (rTHA) remains a subject of debate, with concerns over potential complications arising from stem retention. This study aimed to investigate the re-revision rates due to aseptic loosening of the stem, overall re-revision rates, dislocation rates, and factors influencing these outcomes in rTHA with a retained well-fixed femoral stem.

MATERIALS AND METHODS

A systematic search was conducted across several databases including PubMed, EMBASE, and CENTRAL to identify pertinent publications from their inception through 2023. We specifically focused on studies that reported outcomes of rTHA with retained well-fixed femoral stems. The study designs incorporated in our research encompassed both cohort studies and case series studies. Thirty-five studies involving isolated acetabular revision and retaining the stem were included, representing a total of 3497 patients. Data extraction was tailored to the study questions. Meta-analyses, meta-regression, and subgroup analyses were conducted to evaluate the outcomes and their relationship with various factors. Pooled results, meta-regression, and subgroup analyses were performed using random-effects models. To assess and reduce bias, we employed Egger's test and the trim and fill method.

RESULTS

The meta-analysis included 3497 patients with a mean follow-up of 9.28 years. The 10-year risk of re-revision after retaining femoral stem using highly cross-linked polyethylene was 1.7% (95% CI 1.1%-2.3%; I2: 60%) for stem aseptic loosening and 8.8% (95% CI 6.2%-11.4%; I2: 78%) overall re-revision. Dislocation risk was 5.7% (95% CI 4.1-7.0%; I2: 61%). Ceramic heads showed lower stem failure risk than metal heads in long-term follow-ups (P < 0.001). The posterolateral approach in revision surgery resulted in better long-term outcomes compared to the direct lateral approach (P < 0.001). Follow-up duration, timeline of study, Harris Hip Score, type of stem fixation, femoral head material, BMI, age, stem age, and surgical approach were evaluated as influential factors on these outcomes.

CONCLUSION

The re-revision rate due to aseptic loosening of the retained stem during rTHA was found to be significantly low, supporting the idea of retaining well-fixed stems during rTHA. The overall re-revision and dislocation rates also presented comparable or better outcomes to prior studies. A range of factors, including the use of highly cross-linked polyethylene and ceramic femoral heads, was found to influence these outcomes.

LEVEL OF EVIDENCE

IV.

PROSPERO REGISTRATION NUMBER

CRD42022351157.

30-day to 10-year mortality rates following total hip arthroplasty: a meta-analysis of the last decade (2011-2021)

BACKGROUND

Mortality after total hip arthroplasty (THA) is a rare but devastating complication. This meta-analysis aimed to: (1) determine the mortality rates at 30 days, 90 days, 1 year, 5 years and 10 years after THA; (2) identify risk factors and causes of mortality after THA.

METHODS

Pubmed, MEDLINE, Cochrane, EBSCO Host, and Google Scholar databases were queried for studies reporting mortality rates after primary elective, unilateral THA. Inverse-proportion models were constructed to quantify the incidence of all-cause mortality at 30 days, 90 days, 1 year, 5 years and 10 years after THA. Random-effects multiple regression was performed to investigate the potential effect modifiers of age (at time of THA), body mass index, and gender.

RESULTS

A total of 53 studies (3,297,363 patients) were included. The overall mortality rate was 3.9%. The 30-day mortality was 0.49% (95% CI; 0.23-0.84). Mortality at 90 days was 0.47% (95% CI, 0.38-0.57). Mortality increased exponentially between 90 days and 5 years, with a 1-year mortality rate of 1.90% (95% CI, 1.22-2.73) and a 5-year mortality rate of 9.85% (95% CI, 5.53-15.22). At 10-year follow-up, the mortality rate was 16.43% (95% CI, 1.17-22.48). Increasing comorbidity indices, socioeconomic disadvantage, age, anaemia, and smoking were found to be risk factors for mortality. The most commonly reported causes of death were ischaemic heart disease, malignancy, and pulmonary disease.

CONCLUSIONS

All-cause mortality remains low after contemporary THA. However, 1 out of 10 patients and 1 out of 6 patients were deceased after 5 years and 10 years of THA, respectively. As expected, age, but not BMI or gender, was significantly associated with mortality.

Survivorship of the retained femoral component after revision total hip arthroplasty: A systematic review and meta-analysis

Objective

This systematic review and meta-analysis aimed to estimate re-revision rates of retained femoral components after revision of total hip arthroplasty (THA).

Methods

Papers were searched in the PubMed, Embase, Web of Science, and Cochrane Library databases with predetermined keywords from January 2000 to January 2022. The studies reporting the re-revision rates of retained stems after revision THA were identified. Pooled rates of re-revision for any reason and aseptic loosening were calculated using a random-effects model or a fixed-effects model based on the results of heterogeneity assessment after the Freeman–Tukey double-arcsine transformation. A meta-regression was performed to explore potential sources of heterogeneity.

Results

There were 20 studies with 1,484 hips that received the isolated cup revision with the femoral component retained. The pooled re-revision rate of retained stems was 1.75% [95% confidence interval (CI) 0.43%–3.65%]. The re-revision rate of retained stems due to aseptic loosening was 0.62% (95% CI, 0.06%–1.55%). The meta-regression showed that the fixation type (cemented or cementless) was related to the re-revision rate for any reason and the re-revision rate for aseptic loosening.

Conclusion

Based on the existing evidence, the isolated cup revision with a stable stem in situ yields low re-revision rates. The cement status of retained stems may influence the survivorship of stems.

LncRNA Neat1 promotes the macrophage inflammatory response and acts as a therapeutic target in titanium particle-induced osteolysis

Aseptic loosening (AL), secondary to particle-caused periprosthetic osteolysis, is one of the main reasons of artificial joint failure. Suppressing the macrophage inflammatory response caused by wear particles extends the life of prosthesis, and the long noncoding RNAs (lncRNAs) may play a predominant part in it. Here, titanium particles' (TiPs') stimulation increases both the cytoplasmic and nuclear levels of lncRNA Neat1 in bone marrow derived macrophages (BMDMs), which further induces the inflammatory response. Mechanically, Neat1 facilitates Bruton's tyrosine kinase (BTK) transcription by reducing the transcriptional factor KLF4, which further activates the NF-κB pathway, NLRP3 inflammation, and M1 polarization in BMDMs. Cytoplasmic Neat1 also works as an miRNA sponge in miR-188-5p-regulated BTK expression in the post-transcriptional stage. In vivo, Neat1 downregulation can reduce the TiP-induced pro-inflammatory factors and reverse the osteolysis induced by BTK overexpression. In addition, the PLGA-based microparticles loaded with si-Neat1 are developed for the treatment of the mouse calvarial osteolysis model via local injection, presenting satisfactory anti-osteolysis efficacy. These findings indicate that Neat1 is a key regulator of AL. STATEMENT OF SIGNIFICANCE: Due to released particles, aseptic loosening (AL) is the most common reason for prosthesis failure and surgical revision and represents a substantial economic burden worldwide. Herein, we reported that lncRNA Neat1 is a key regulator in regulating wear particles-induced osteolysis by activating NF-κB pathway, NLRP3 inflammation and M1 polarization via BTK, and the underlying mechanisms of Neat1-BTK interaction were further portrayed. For potential clinical application, the microparticles are developed for effective si-Neat1 delivery, leading to a dramatically enhanced effect for the treatment of osteolysis, which might be a novel strategy to extend the life of the implant.

Long-Term Survival (up to 34 Years) of Retained Cementless Anatomic Femoral Stem in Patients <50 Years Old

BACKGROUND

There is a paucity of studies longer than 30 years to determine clinical and radiographic results of retained cementless anatomic stem. The purpose of this study is to determine the long-term (up to 34 years) survival rate of the retained cementless anatomic femoral stem in patients <50 years of age.

METHODS

Isolated cup revision was performed with retaining primary cementless anatomic femoral stem in 206 patients (149 men and 57 women). Clinical and radiographic results were monitored at each follow-up. At the latest follow-up, computed tomography scans were carried out in all hips to determine the prevalence of osteolysis. The mean follow-up of the retained femoral stem was 30.3 years (range 27-34). The mean follow-up of the revised cup was 25.5 years (range 22-29).

RESULTS

The mean Harris Hip Score was 91 ± 7.8 points (range 71-100) and the mean Western Ontario and McMaster Universities Osteoarthritis score was 16 ± 7 points (range 7-34) at the final follow-up. The mean University of California, Los Angeles activity score was 7 ± 4 points (range 5-10) at the final follow-up. The overall survival rate of retained cementless femoral stems was 98.9% (95% confidence interval 91-100) at 30.3 years. The survival rate of the revised cup was 93% (95% confidence interval 89-98) at 25.5 years.

CONCLUSION

The rate of aseptic loosening of already osseointegrated femoral stem remains low with ceramic-on-ceramic bearing in young active patients.