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

Clinical outcomes and complications of a non-modular dual-mobility acetabular device, minimum 2 years follow-up

INTRODUCTION

Non-modular dual-mobility (DM) acetabular bearing constructs are becoming more popular due to their potential advantages for addressing range of motion (ROM) and stability. The objective of this post-market clinical study was to assess clinical outcomes, including patient satisfaction, pain and function, survivorship, and component positioning, in patients ⩾2 years after primary THA using non-modular DM acetabular components.

METHODS

This retrospective, multicentre study evaluated complications and functional outcomes in recipients of non-modular DM acetabular constructs at least 2 years post-THA. Our primary outcomes included the dislocation rate and mean Hip disability and Osteoarthritis Outcomes Score (HOOS). Secondary outcomes included radiographic measurements, patient satisfaction, Forgotten Joint Score (FJS), Harris Hip Score (HHS), and survivorship.

RESULTS

316 eligible patients enrolled in this study across 3 sites, including 168 men (53%) and 148 women (47%). The cohort averaged 5.37 years post-THA (range 2.2-10.1 years) at the study visit. The mean FJS, HHS, and HOOS were good to excellent, with values of 82.3, 90.7, and 92.0, respectively. Patient satisfaction averaged 4.68, between "Very Good" (4) and "Excellent" (5). Minimal radiolucent lines (RLL) surrounded the acetabulum. More RLL surrounded the femur, but most lines were less than 1 mm (4.7% of the study population). There were few adverse events (4 events, 1.3%). Three revisions were performed (0.9%), with one patient requiring removal of the acetabular cup.

DISCUSSION

The high mid- to long-term survivorship and low to no dislocation and reoperation rates indicate this acetabular DM device is a viable option for THA patients. The patient metrics reflect satisfaction, alleviated pain, and restored function with a low risk of adverse outcomes.

Dual-mobility implants in primary and revision total hip arthroplasty: A systematic review and meta-analysis

Purpose

Total hip arthroplasty (THA) is a common and successful operation. However, dislocation remains a significant cause of implant failure in fixed-bearing designs. This study investigated the effect of dual-mobility implants (DM) compared to fixed-bearing (FB) implants on all-cause revisions, revisions due to dislocation, post-operative complications and functional scores in patients undergoing primary and revision THA.

Methods

A systematic review was performed including studies that compared DM with FB implants in primary or revision THA according to PRISMA guidelines, and was registered in PROSPERO (ID CRD42023403736). The Cochrane Library, Embase, MEDLINE, Web of Science, and Scopus were searched from the time of database inception to March 12, 2023. Eligible studies underwent meta-analysis and risk of bias assessment using the ROBINS-I tool. Treatment effects were assessed using odds ratios and data were pooled using a random-effects maximum-likelihood, where appropriate.

Results

Eight comparative, non-randomised studies involving 2810 DM implants and 3188 FB implants were included. In primary THA, there was an imprecise estimate of the difference in all-cause revision (OR 0.82, 95 % CI 0.25-2.72) and a significant benefit for the DM cohort in revision due to dislocation (OR 0.08, 95 % CI 0.02-0.28). In revision THA, the DM cohort showed benefit in all-cause revision (OR 0.57, 95 % CI 0.31-1.05) and revision due to dislocation (OR 0.14, 95 % CI 0.04-0.53). DM implants were associated with a lower incidence of implant dislocation and infection. The analysis of functional outcomes was limited due to reporting limitations. No intraprosthetic dislocations were observed.

Conclusion

The results suggest that contemporary DM designs may be advantageous in reducing the risk of all-cause revision, revision due to dislocation, and post-operative complication incidence at mid-term follow-up. Further high-quality prospective studies are needed to evaluate the long-term risk profile of this design, especially in the revision context.

Dislocation of primary total hip arthroplasty: Analysis of risk factors and preventive options

Total hip arthroplasty (THA) is one of the most successful elective operations in orthopedic surgery for improving pain and functional disability in patients with end-stage joint disease. However, dislocation continues to be a troublesome complication after THA, as it is a leading cause of revision and is associated with substantial social, health, and economic costs. It is a relatively rare, usually early occurrence that depends on both the patients' characteristics and the surgical aspects. The most recent and important finding is the special attention to be given preoperatively to spinopelvic mobility, which is closely related to the incidence of dislocation. Consequently, clinical and radiographic assessment of the lumbar spine is mandatory to identify an altered pelvic tilt that could suggest a different positioning of the cup. Lumbar spinal fusion is currently considered a risk factor for dislocation and revision regardless of whether it is performed prior to or after THA. Surgical options for its treatment and prevention include the use of prostheses with large diameter of femoral head size, dual mobility constructs, constrained liners, and modular neck stems.

Dual-Mobility Acetabular Components in Primary Total Hip Arthroplasty Do Not Increase the Risk of Complication Compared to Conventional Articulations: A Matched Cohort Comparative Analysis

Background

A recent National Joint Registry report suggests a higher local complication risk for dual-mobility (DM) total hip arthroplasty (THA) compared to conventional articulation THA. This report may be subject to data heterogeneity with multiple confounders. Controlling for these factors by matching demographic characteristics may give different results. We aim to compare 2-year local complication rates between matched DM and conventional THAs in primary hip osteoarthritis.

Methods

Data were collected for consecutive primary THAs undertaken via a posterior approach. The conventional articulation and DM cohorts were matched 3:1 for age, gender, American Society of Anesthesiology grade, body mass index, and operative time using a propensity score and nearest neighbor matching method. Outcome measures were 2-year local complication rates, reoperation rates, systemic complication rates, and mortality rates. Demographic and outcome data were compared, and cumulative survival rates (%) were assessed using Kaplan-Meier methodology with a 2-year local complication as the endpoint. Statistical significance was set at P < .05.

Results

Four hundred twelve THAs were included: 309 conventional and 103 DM articulations. There were no statistically significant differences between DM and conventional articulation THAs for local complications (7 [6.8%] vs 23 [7.4%], P = .820), reoperations (3 [2.9%] vs 4 [1.3%], P = .374), systemic complications (3 [2.9%] vs 4 [1.3%], P = .374), or 90-day mortality (1 [1%] vs 2 [0.6%], P = 1.000). Kaplan-Meier survival analysis demonstrated similar 2-year survival rates for conventional THAs compared to DM THAs (93.3% [standard error, 0.014] vs 91.9% [standard error, 0.031], P = .906).

Conclusions

This matched study shows that there is no difference in local complication rates between DM and conventional THA articulations.

Custom three-dimensional printed implants for reconstruction of oncologic pelvic defects

The use of three-dimensional printed implants in the field of orthopedic surgery has become increasingly popular and has potentiated hip reconstruction in the setting of oncologic resections of the pelvis and acetabulum. In this review, we examine and discuss the indications and technical considerations for custom implant reconstruction of pelvic defects.

Central Fracture-Dislocation of the Hip with Ipsilateral Femoral Neck Fracture in an Elderly Patient with Parkinsonism Managed with Dual Mobility Total Hip Arthroplasty: A Case Report and Review of Literature

Introduction

The combination of a central fracture-dislocation of the hip, acetabulum fracture, and neck of the femur fracture is a rare injury, with a few reports described in the literature. Guidelines regarding managing this type of injury in single or multiple stages, the requirement of acetabular augmentation with plates, metal rings or cages, and the implant selection in elderly patients are not adequately defined while planning a total hip arthroplasty (THA). The successful management of such a complex fracture pattern in an elderly patient with neurodegenerative disorder is described in our case report.

Case Report

An 81-year-old male presented to our outpatient department with a 2-month-old neglected post-traumatic central fracturedislocation of the right hip with an ipsilateral femoral neck fracture. The patient had a known case of Parkinson's disease on treatment with oral medication. A single-stage hybrid THA with dual mobility (DM) prosthesis was done with femoral head autograft acetabular impaction bone grafting. The patient was mobilized full weight bearing with the support of a walker on the 2nd post-operative day. At the 1-year follow-up the functional Harris hip score was 87. Radiographs revealed a well-healed acetabular fracture with the incorporation of a bone graft. No signs of implant loosening were observed. We did not encounter any complications such as dislocation, infection, and heterotrophic ossificans.

Conclusion

Management of central fracture-dislocation of the hip with delayed one-staged THA has a good functional outcome. DM cup is essential in patients with parkinsonism and other neurodegenerative disorders.

Instantaneous Generation of Subject-Specific Finite Element Models of the Hip Capsule

Subject-specific hip capsule models could offer insights into impingement and dislocation risk when coupled with computer-aided surgery, but model calibration is time-consuming using traditional techniques. This study developed a framework for instantaneously generating subject-specific finite element (FE) capsule representations from regression models trained with a probabilistic approach. A validated FE model of the implanted hip capsule was evaluated probabilistically to generate a training dataset relating capsule geometry and material properties to hip laxity. Multivariate regression models were trained using 90% of trials to predict capsule properties based on hip laxity and attachment site information. The regression models were validated using the remaining 10% of the training set by comparing differences in hip laxity between the original trials and the regression-derived capsules. Root mean square errors (RMSEs) in laxity predictions ranged from 1.8° to 2.3°, depending on the type of laxity used in the training set. The RMSE, when predicting the laxity measured from five cadaveric specimens with total hip arthroplasty, was 4.5°. Model generation time was reduced from days to milliseconds. The results demonstrated the potential of regression-based training to instantaneously generate subject-specific FE models and have implications for integrating subject-specific capsule models into surgical planning software.

Outcome measures in total hip arthroplasty: have our metrics changed over 15 years?

INTRODUCTION

Consensus has not been reached regarding ideal outcome measures for total hip arthroplasty (THA) clinical evaluation and research. The goal of this review was to analyze the trends in outcome metrics within the THA literature and to discuss the potential impact of instrument heterogeneity on clinical practice.

MATERIALS AND METHODS

A PubMed search of all manuscripts related to THA from January 2005 to December 2019 was performed. Statistical and linear regression analyses were performed for individual outcome metrics as a proportion of total THA publications over time.

RESULTS

There was a statistically significant increase in studies utilizing outcomes metrics between 2005 and 2019 (15.1-29.5%; P < 0.001; R² = 98.1%). Within the joint-specific subcategory, use of the Harris Hip Score (HHS) significantly decreased from 2005 to 2019 (82.8-57.3%; P < 0.001), use of the Hip Disability and Osteoarthritis Outcome Score (HOOS) significantly increased (0-6.7%; P < 0.001), and the modified HHS significantly increased (0-10.5%; P < 0.001). In the quality of life subcategory, EQ-5D demonstrated a significant increase in usage (0-34.8%; P < 0.001), while Short Form-36 significantly decreased (100% vs. 27.3%; P = 0.008).

CONCLUSIONS

The utilization of outcome-reporting metrics in THA has continued to increase, resulting in added complexity within the literature. The utilization rates of individual instruments have shifted over the past 15 years. Additional study is required to determine which specific instruments are recommended.

Dual Mobility Cups as the Routine Choice in Total Hip Arthroplasty

Background and Objectives: Total hip arthroplasty (THA) is considered the most successful surgical procedure in orthopedics. However, dislocation remains the main indication for surgical revision. New designs of dual mobility cups (DMC) have lowered the classical complications and have extended the indications of DMC in elective surgeries. Our aim is to assess the trend of DMC indications in THA as well as the incidence of their dislocation. Materials and Methods: We retrospectively reviewed all patients undergoing THA with DMC during the years 2015 and 2021. The original indication for DMC included patients sustaining neck of femur fractures (NOF#) and associated risk factors for dislocations. Five years later, DMC was considered our standard of care in total hip arthroplasty. The approach (anterolateral or posterolateral) was chosen by the surgeon according to his/her preferences, as was the implant. Data collected included patients' demographics, diagnosis, admission time, surgical approach, cup models, and inclination and complications. Patients sustaining a hip dislocation were prospectively reviewed and assessed for treatment received, new dislocations, and need for surgical revision. Two groups were created for the analysis according to the presence or absence of dislocation during follow-up. Results: In the analysis, 531 arthroplasties were included (mean age 72.2 years) with a mean follow-up of 2.86 years. The trend of indications for DMC increased from 16% of THA in 2015 to 78% of THA in 2021. We found a total of 8 dislocations (1.5%), none of them associated with elective surgery. Closed reduction was unsatisfactory in four cases (50%). There was one case of intraprosthetic dislocation. Dislocations were associated to smaller heads (22 mm) (1.5% vs. 25%, p = 0.008) and cups (51.2 mm vs. 48.7 mm, p = 0.038) and posterior approach (62.5% vs. 37.5%, p = 0.011). Conclusion: Dual mobility cups are a great option to reduce the risk of dislocation after a THA both in the neck of femur fractures and elective cases. The use of an anterolateral approach in THA after a neck or femur fracture might considerably decrease the risk of dislocation.

What affects the biocompatibility of polymers?

In recent decades synthetic polymers have gained increasing popularity, and nowadays they are an integral part of people's daily lives. In addition, owing to their competitive advantage and being susceptible to modification, polymers have stimulated the fast development of innovative technologies in many areas of science. Biopolymers are of particular interest in various branches of medicine, such as implantology of bones, cartilage and skin tissues as well as blood vessels. Biomaterials with such specific applications must have appropriate mechanical and strength characteristics and above all they must be compatible with the surrounding tissues, human blood and its components, i.e. exhibit high hemo- and biocompatibility, low or no thrombo- and carcinogenicity, foreign body response (host response), appropriate osteoconduction, osteoinduction and mineralization. For biocompatibility improvement many surface treatment techniques have been utilized leading to fabricate the polymer biomaterials of required properties, also at nanoscale. This review paper discusses the most important physicochemical and biological factors that affect the biocompatibility, thus the reaction of the living organism after insertion of the polymer-based biomaterials, i.e. surface modification and/or degradation, surface composition (functional groups and charge), size and shapes, hydrophilic-hydrophobic character, wettability and surface free energy, topography (roughness, stiffness), crystalline and amorphous structure, nanostructure, cell adhesion and proliferation, cellular uptake. Particularly, the application of polysaccharides (chitosan, cellulose, starch) in the tissue engineering is emphasized.

Dual Mobility Reduces Dislocations-Why I Use It in All Revisions

BACKGROUND

Instability remains the most common complication after revision total hip arthroplasty (THA) and presents a unique treatment dilemma for the orthopedic surgeon. Dual mobility (DM) bearing articulations have been used in France since the 1970s, but have only become more widely adopted in the United States over the last decade. The purpose of this symposium was to discuss the role for DM bearings in revision THA.

METHODS

We reviewed the existing literature on outcomes after DM bearing articulations in revision THA. We also report several case examples of the use of DM in difficult revision THA cases, including acetabular bone loss, failed constrained liner, and adverse local tissue reaction. Finally, we briefly discuss the limitations associated with the use of DM.

RESULTS

Several large retrospective series demonstrate that DM bearings reduce the incidence of dislocation after revision THA when compared with conventional single bearing THA. Specific complications related to DM bearings including polyethylene wear, loosening, intraprosthetic dislocation, and corrosion remain a concern, but appear to have drastically improved over time with modern implant designs.

CONCLUSION

Contemporary DM designs have been established as an effective bearing option to reduce instability in revision THA, although concerns do exist. High-quality prospective studies are necessary to further define the role this bearing option has in the coming years.

Risk Factors for Revision After Early and Delayed Total Hip Arthroplasty Dislocation. An Analysis of Lithuanian Arthroplasty Register

Introduction: Despite relatively low incidence, dislocation remains one of the main reasons for total hip arthroplasty (THA) revision. It is a devastating complication for a patient and a surgeon, and has high burden on the healthcare system. The aim of the present study was to assess and compare the risk factors for revision after early and delayed THA dislocations.

Methods: Some 3403 THA through posterior approach for primary osteoarthritis were retrospectively studied in the Lithuanian Arthroplasty Register from 2011 to 2018. Three months after THA was the splitting time between the first event of early and delayed dislocations. Revision was set as outcome measure. Gender, affected side, number of dislocations, femoral head and neck size, and prosthesis fixation type were tested as risk factors for revision after early and delayed THA dislocations.

Results: Dislocation occurred in 108 patients (3.2%), and 26 cases (0.8%) required revision. Men had statistically significant higher risk for revision due to early dislocation [hazard ratio (HR) 4.7; 1.3-17.7 confidence interval (CI)] and considerably lower risk for revision due to delayed dislocation (HR 0.5; 0.1-1.7 CI). The left side THA had twice the risk as compared to the right in the early settings (HR 2.1; 0.6-6.9 CI) which equalized after three months (HR 1.1; 0.4-3.1 CI). Some 32 mm femoral head had significantly lower risk in the early group as compared to 28 mm head (HR 0.3; 0.1-0.5 CI). Short head was associated with increased risk for revision after early dislocation, although, not statistically significant. Prosthesis fixation type was not a risk factor for revision surgery neither after early nor after delayed dislocation.

Conclusion: The unique finding of gender separation was found -- men tend for revision after early dislocation and women after delayed dislocation. In early stage, additional precautions should be considered when 28 mm short metal heads are used.