The benefit of the systematic revision of the acetabular implant in favor of a dual mobility articulation during the treatment of periprosthetic fractures of the femur: a 49 cases prospective comparative study

Cementless, modular, titanium stem in Vancouver B2 and B3 periprosthetic femoral fractures

INTRODUCTION

The periprosthetic femoral fracture (PFF) is a serious complication after primary total hip arthroplasty. We conducted a retrospective study to determine whether the PRIUS^® system presented similar survival to other existing implants for the treatment of Vancouver B2 or B3 PFFs. Bone consolidation rate, functional results and complications were analysed.

METHOD

This is a bi-centric retrospective study between 2012 and 2017 including 39 patients with (B2/B3) PFFs treated by senior surgeons using a PRIUS^® femoral implant. Implant survival, radiological outcome (fracture healing) and clinical scores (Oxford-OHS, Harris Hip Score-HHS, Postel Merle d'Aubigné-PMA, Devane and Charnley) were analysed. 10 patients had died before data collection and 5 patients were lost to follow-up. A total of 21 patients were able to undergo a clinical and radiological evaluation. The mean follow-up period was 3 years.

RESULTS

The 3-year PRIUS^® stem survival rate was 88.6% [95% CI, 77.2-100]. The consolidation rate was 81% (17/21). The rate of satisfied or very satisfied patients was 85.6% (18/21). Regarding the Devane score, activity level was maintained in 70.6% of cases (12/17) and decreased in 29.4% of cases (5/17), the Charnley score was stable in 94% of cases (16/17) and decreased in 6% of cases (1/17). The mean Oxford score was 28.8/48 (9.3; 16-48), the mean HHS was 67/100 (16.4; 46-91) and the mean PMA score was 12.6/18 (4.5; 2-18).

CONCLUSION

The results in terms of survival rate and bone consolidation are comparable to other literature series. The PRIUS® System can be added to the surgical arsenal in the treatment of (B2/B3) PFF, subject to confirmation of these results in the longer term.

The race for the classification of proximal periprosthetic femoral fractures : Vancouver vs Unified Classification System (UCS) - a systematic review

Background

Periprosthetic femoral fractures (PFFs) represent a major cause for surgical revision after hip arthroplasty with detrimental consequences for patients. The Vancouver classification has been traditionally used since its introduction in 1995. The Unified Classification System (UCS) was described in 2014, to widen the spectrum by aiming for a more comprehensive approach. The UCS also aimed to replace the Vancouver classification by expanding the idea of the Vancouver classification to the whole musculoskeletal apparatus. After introduction of the UCS, the question was raised, whether the UCS found its place in the field of analysing PFFs. Therefore, this systematic review was performed to investigate, the use of the UCS compared to the established Vancouver classification.

Methods

Medline was searched for reports published between 1 January 2016 and 31 November 2020, without language restriction. Included were original articles, irrespective of the level of evidence and case reports reporting on a PFF and using either the Vancouver or the UCS to classify the fractures. Excluded were reviews and systematic reviews.

Results

One hundred forty-six studies were included in the analysis. UCS has not been used in a single registry study, giving a pooled cohort size of 3299 patients, compared to 59,178 patients in studies using the Vancouver classification. Since 2016, one study using UCS was published in a top journal, compared to 37 studies using the Vancouver classification (p=0.29). During the study period, the number of yearly publications remained stagnant (p=0.899).

Conclusions

Despite valuable improvement and expansion of the latter UCS, to date, the Vancouver system clearly leads the field of classifying PFFs in the sense of the common use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05240-w.

Risk factors and modes of failure in the modern dual mobility implant. A systematic review and meta-analysis

Background

The aims of this meta-analysis were to: (1) validate the outcome of modern dual mobility (DM) designs in patients who had undergone primary and revision total hip arthroplasty (THA) procedures and (2) to identify factors that affect the outcome.

Methods

We searched for studies that assessed the outcome of modern DM-THA in primary and revision procedures that were conducted between January, 2000 to August, 2020 on PubMed, MEDLINE, Cochrane Reviews and Embase. The pooled incidence of the most common failure modes and patient reported outcomes were evaluated in patients who have received: (1) primary THA, (2) revision THA for all causes or (3) for recurrent dislocation. A meta-regression analysis was performed for each parameter to determine the association with the outcome. The study design of each study was assessed for potential bias and flaws by using the quality assessment tool for case series studies.

Results

A total of 119 studies (N= 30016 DM-THAs) were included for analysis. The mean follow-up duration was 47.3 months. The overall implant failure rate was 4.2% (primary: 2.3%, revision for all causes: 5.5%, recurrent dislocation: 6.0%). The most common failure modes were aseptic loosening (primary: 0.9%, revision for all causes: 2.2%, recurrent dislocation: 2.4%), septic loosening (primary:0.8%, revision for all causes: 2.3%, recurrent dislocation: 2.5%), extra-articular dislocation (primary:0.6%, revision for all causes:1.3%, recurrent dislocation:2.5%), intra-prosthetic dislocation (primary:0.8%, revision for all causes:1.0%, recurrent dislocation:1.6%) and periprosthetic fracture (primary:0.9%, revision for all causes:0.9%, recurrent dislocation:1.3%). The multi-regression analysis identified younger age (β=-0.04, 95% CI -0.07 – -0.02) and female patients (β=3.34, 95% CI 0.91–5.78) were correlated with higher implant failure rate. Age, gender, posterolateral approach and body mass index (BMI) were not risk factors for extra-articular or intra-prosthetic dislocation in this cohort. The overall Harris hip score and Merle d’Aubigné score were 84.87 and 16.36, respectively. Level of evidence of this meta-analysis was IV.

Conclusion

Modern dual-mobility designs provide satisfactory mid-term implant survival and clinical performance. Younger age and female patients might impact the outcome after DM-THA. Future research directions should focus on, (1) long-term outcome of modern dual-mobility design, including specific concerns such as intra-prosthetic dislocation and elevated metal ion, and (2) cost-effectiveness analysis of dual-mobility implant as an alternative to conventional THA for patients who are at high risk of dislocation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04404-4.

Use of dual mobility components in total hip arthroplasty: Indications and outcomes

Instability after total hip arthroplasty (THA) can be a problematic complication and remains one of the leading causes of revision surgery in the early post-operative period. Dual mobility (DM) implants decrease dislocation risk after THA but they come with their own set of complications. Selective use of DM implants for THA in high risk groups can confer the advantages of this construct while mitigating the risks. In this paper, we review the current literature to examine the evidence for or against use of DM implants in various clinical scenarios and provide an algorithm for when to consider using DM design construct in THA.

Dual-mobility cups could yield lesser infections than conventional cups: a meta-analysis of comparative studies

INTRODUCTION

Dual-mobility cups (DMC) are gaining popularity mainly for their reduced rate of dislocation following total hip arthroplasty (THA). Currently, indication for DMC use extends beyond patients with high risk of dislocation or revision THA cases. Many authors reported DMC outcomes in primary THA for all aetiologies. However, some reports claimed that the use of DMC is accompanied with higher rates of infection compared with conventional cups (CC) in both primary and revision THA.

RESEARCH QUESTION

Does the use of DMC generate higher rates of infection when compared with conventional cups?

OBJECTIVES

The aim of this meta-analysis was to look for significant difference in the rate of post-operative infection between DMC cups and conventional cups.

METHODOLOGY

MEDLINE, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar were searched since inception. Only studies with comparative design reporting the outcome infection rate were included.

RESULTS

Seventeen retrospective comparative studies were located comprising 248,541 patients: 16,020 in the DMC group and 232,521 in the CC group. The mean follow-up period was 37.5 ± 42 and 50.2 ± 48.7 months for the DMC and CC groups, respectively. The meta-analytical results indicated the following: (a) significantly lesser infections following DMC compared with CC in revision THA (odds ratio (OR) = 0.75 (95% CI = 0.653 to 0.874, P = 0.0002, I² = 25%); (b) for primary THA and for large-sampled registries, significance was found using only the fixed-effects model estimate; and (c) no significant difference was found for the subgroup of cohort studies.

CONCLUSION

Our results clearly refute the claim that DMC would yield higher rates of infection. On the contrary, the findings demonstrated that the use of DMC reduces the risk of post-operative infection in revision THA and a similar lower infection trend for primary THA when compared with the standard cups.

[Periprosthetic fractures: basics, classification and treatment principles]

Periprosthetic fractures (PPFx) are becoming an increasingly important topic in orthopedics and trauma surgery due to the rising number of endoprosthetic joint replacements. The recently published unified classification system (UCS) has replaced numerous historical classification systems and can be applied to all PPFx regardless of the bone or joint involved. The treatment of PPFx requires individual therapeutic concepts taking patient-dependent and patient-independent factors into consideration. The conservative treatment of PPFx is only justified in exceptional situations. In contrast, the choice between operative treatment and deciding between osteosynthesis or revision arthroplasty is particularly based on the assessment of the implant stability. In order to achieve fracture consolidation and also a good functional outcome, knowledge of the basic biomechanical principles of operative (osteosynthesis or endoprosthesis) treatment of periprosthetic fractures is necessary.

The efficacy of dual-mobility cup in preventing dislocation after total hip arthroplasty: a systematic review and meta-analysis of comparative studies

PURPOSE

Although long-term reports of total hip arthroplasty (THA) showed successful results, instability remains a major complication. Recently, dual-mobility cups (DMC) have gained more and more interest among clinicians, with encouraging results in terms of lower rate of dislocation associated with good clinical results, but a lack of evidence exists regarding the real efficacy of this implant design compared to traditional fixed-bearing total hip arthroplasties.

METHODS

A systematic search was performed in PubMed, Google scholar, Cochrane Library, and EMBASE by two independent reviewers for comparative studies available till December 2017, with the primary objective to demonstrate a real lower dislocation rate of DMC implants compared to unipolar fixed-bearing cup designs. A meta-analysis was conducted with the collected pooled data about dislocation rate, calculating the risk difference (RD) and relative risk (RR) with 95% CI for dichotomous variables. Heterogeneity was tested using the χ² and Higgins' I² tests. A fixed-effect model was used because the statistical heterogeneity was below 50%.

RESULTS

After performing a critical exclusion process, the number of eligible studies included for final synthesis considered was 15, describing the results of a total of 2408 total hip arthroplasties (50.6% with a dual-mobility acetabular cup design, 49.4% with a standard fixed-bearing design). The fixed-effect meta-analysis showed a slight significant risk ratio of 0.16 (95% CI, 0.09, 0.28; I² = 0%, p < 0.00001); a statistically significant difference in favor of the DMC group was maintained also considering only primary or revision arthroplasties, traumatic fractures or elective patients with diagnosis of osteoarthritis, avascular osteonecrosis or rheumatic arthritis.

CONCLUSIONS

With the intrinsic limitations of our study design and based on the current available data, this study demonstrates that dual-mobility acetabular components decrease the risk of post-operative instability also in high-risk patients, both in primary and revision hip arthroplasties. However, new high-quality studies, possibly with a randomized control design, should be undertaken in order to strengthen the present data.

STUDY DESIGN

Level of Evidence III, therapeutic study.