Dual Mobility Articulations Research Articles

Dual Mobility Articulations in Primary Total Hip Arthroplasty: Midterm Outcomes from the American Joint Replacement Registry

In recent years, there has been an increased utilization of dual mobility (DM) implants in primary total hip arthroplasty (THA) to mitigate the risk of postoperative hip instability. This study aimed to present midterm outcomes of DM bearings in primary THA using data from the American Joint Replacement Registry (AJRR). Screening was conducted on patients aged ≥ 65 years who underwent primary THA between 2012 and 2018. Patients were categorized into three groups: (1) DM articulation, (2) ≤ 32 mm femoral head, and (3) ≥ 36 mm femoral head. Multivariable statistical modeling was employed to analyze patient and hospital characteristics, minimizing potential confounding variables and identifying independent associations with revision. Cox proportional hazards regression analyses were used to assess all-cause revision and revision specifically for instability. A total of 207,526 primary total hip arthroplasties (THAs) were identified. Among them, 13,896 (6.7%) utilized dual mobility (DM) articulation, 60,358 (29.1%) had a femoral head size of ≤ 32 mm and 133,272 (64.2%) had a femoral head size of ≥ 36 mm. At the eight-year follow-up, the all-cause revision rate was higher in the DM group (3.5%, 95% confidence interval [CI] 3.1 to 4.1) compared to the ≤ 32 mm (2.6%, 95% CI 2.5 to 2.8) and ≥ 36 mm (2.7%, 95% CI 2.5 to 2.9) groups. However, the revision rate for instability was comparable among the DM (0.4%, 95% CI 0.2 to 0.5), ≤ 32 mm (0.5%, 95% CI 0.4 to 0.5), and ≥ 36 mm (0.3%, 95% CI 0.3 to 0.4) groups at eight-year follow-up. The utilization of DM was associated with higher overall revision rates. However, no significant differences in rates of revision for instability were observed among any of the bearing surface groups. These findings may be attributed to surgeons selectively utilizing DM articulations in higher-risk patients.

Dual-Mobility Articulations in Revision Total Hip Arthroplasty: A Comparison with Metal or Ceramic on Highly Cross-Linked Polyethylene and Constrained Articulations.

The increased availability of dual-mobility acetabular constructs (DMCs) provides surgeons with a newer option to increase the effective femoral head size in revision total hip arthroplasty (rTHA). We sought to evaluate risks of re-revision and prosthetic dislocation following rTHA involving a DMC compared with other articulations. A cohort study was conducted using data from a U.S. integrated health-care system's Total Joint Replacement Registry. Adult patients who underwent primary THA and went on to undergo an aseptic rTHA in 2002 to 2022 were identified. Patients who received a DMC, a constrained liner, or a metal or ceramic unipolar femoral head on highly cross-linked polyethylene (XLPE) at the time of rTHA were the treatment groups. Subsequent aseptic re-revision and dislocation were the outcomes of interest. Multivariable Cox proportional-hazards regression was used to evaluate the risks of the outcomes, with adjustment for patient, operative, and surgeon confounders. The analyzed rTHAs comprised 375 with a DMC, 268 with a constrained liner, 995 with a <36-mm head on XLPE, and 2,087 with a ≥36-mm head on XLPE. DMC utilization increased from 1.0% of rTHAs in 2011 to 21.6% in 2022. In adjusted analyses, a higher re-revision risk was observed for the constrained liner (hazard ratio [HR] = 2.43, 95% confidence interval [CI] = 1.29 to 4.59), <36 mm on XLPE (HR = 2.05, 95% CI = 1.13 to 3.75), and ≥36 mm on XLPE (HR = 2.03, 95% CI = 1.19 to 3.48) groups compared with the DMC group. A higher dislocation risk was observed in both XLPE groups (<36 mm: HR = 2.04, 95% CI = 1.33 to 3.14; ≥36 mm: HR = 2.46, 95% CI = 1.69 to 3.57) compared with the DMC group; a nonsignificant trend toward a higher dislocation rate in the group with a constrained liner than in the DMC group was also observed. In a large U.S.-based cohort, rTHAs using DMCs had the lowest re-revision risk and dislocation risk. Both outcomes were significantly lower than those using a unipolar femoral head on XLPE, re-revision risk was significantly lower than using a constrained liner, and dislocation risk trended toward a lower risk than using a constrained liner. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

FUNCTIONAL OUTCOME OF DUAL MOBILITY ARTICULATIONS: IS THERE A COMPROMISE?

Dislocation is still one of the more common reasons for revision of THR.Registry and large institutional data has demonstrated the effectiveness of Dual Mobility articulations in reducing revision for dislocation after THR. There is little data about whether the use of dual mobility is associated with a comprised clinical functional outcome.This study aimed to ascertain whether the use of Dual Mobility articulations (DM cups) comes within a compromise to the functional of the THR procedure as measured by the Hip disability and Osteoarthritis Outcome Score (HOOS).Utilising a retrospective design, patients were grouped into those with DM cups with 12 PROMs (Cohort 1) or a large data base of all THR procedures also with a complete set of 12 month PROMs (Cohort 2). The 2 groups were matched for age and gender through propensity score matching. The comparison focused on five domains of the HOOS: Pain, Symptoms, Activities of Daily Living (ADL), Sports and Recreation, and Quality of Life (QOL) at 6- and 12-months post-operation.12 month PROM data suggested a convergence in scores for several domains, no uniform superiority of one articulation type over the other was found across all domains. These results suggest that both DM cup and standard articulations can effectively improve patient-reported outcomes in THR surgeries, but there are variations in recovery within each cohort that are potentially influenced by factors beyond the articulation type.This study contributes to the ongoing dialogue on optimising prosthetic selection to enhance recovery trajectories and quality of life for THR patients, emphasising the critical role of evidence-based decision-making in orthopaedic surgery.

10-Year Cumulative Incidence and Indications for Revision Total Joint Arthroplasty for Patients Who Have Ehlers-Danlos Syndrome

BackgroundLong-term complications following total joint arthroplasty are not well established for patients who have Ehlers-Danlos syndrome (EDS), a group of connective tissue disorders. This study compared 10-year incidence of revision surgery after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in patients who have and do not have EDS. MethodsA retrospective cohort analysis was conducted using a national all-payer claims database from 2010 to 2021 to identify patients who underwent primary TKA or THA. Patients who had and did not have EDS were propensity score–matched by age, sex, and a comorbidity index. Kaplan-Meier analyses and Cox proportional hazard models were used to determine the cumulative incidence and risks of revision experienced by patients who have and do not have EDS. ResultsThe EDS patients who underwent TKA had a higher risk of all-cause revision (hazard ratio [HR]: 1.50, 95% confidence interval [95% CI]: 1.09 to 2.07, P < .014) and risk of revision due to instability (HR = 2.49, 95% CI: 1.37 to 4.52, P < .003). The EDS patients who underwent THA had a higher risk of all-cause revision (HR = 2.32, 95% CI: 1.47 to 3.65, P < .001), revision due to instability (HR = 4.26, 95% CI: 2.17 to 8.36, P < .001), and mechanical loosening (HR = 3.63, 95% CI: 2.05 to 6.44, P < .001). ConclusionsPatients who had EDS were found to have a higher incidence of revision within 10 years of undergoing TKA and THA compared to matched controls, especially for instability. Patients who have EDS should be counseled accordingly. Surgical technique and implant selection should include consideration for increased constraint in TKA and larger femoral heads or dual mobility articulations for THA.

Contemporary Isolated Bearing Exchange for the Management of Hip Instability Following Primary Total Hip Arthroplasty

BackgroundIsolated ball and liner exchanges (IBLEs) can be performed to increase hip joint stability, but historical results have been mixed due to a lack of head size options or dual mobility articulations. The purpose of this study was to evaluate the contemporary results of IBLEs in patients who have instability following primary total hip arthroplasty (THA). MethodsWe retrospectively reviewed 65 primary THAs from 2016 to 2020 with hip instability undergoing IBLE or conversion to dual mobility articulation. There were 31 men and 34 women who had an average age of 70 years (range, 26 to 92). The mean time to revision from primary was 40.1 months (range, 1 to 120). In 52 cases, IBLE was performed using conventional bearings, while 13 hips were converted to dual mobility. Radiographic factors, including acetabular component orientation, reproduction of hip joint offset, leg lengths, and outcomes such as recurrent instability requiring subsequent revision and patient-reported outcome measure, were recorded and compared. ResultsThere were 12 (18.4%) hips that experienced subsequent instability and required another revision (17.3% ball and liner exchange versus 23.1% dual mobility articulation, P = .615). The mean time to rerevision for instability was 17.1 months. There were no significant differences in either acetabular component anteversion (P = .25) or restoration of hip joint offset (P = .87) in patients who required another revision for instability compared to those who did not, respectively. At 1 year, patients undergoing conventional bearing exchange reported higher Hip Dysfunction Osteoarthritis Outcome Score for Joint Replacements (P = .002) and Veterans Rand physical component (P = .023) scores compared to those who underwent a conversion to dual mobility articulation. Only age > 75 years at the time of surgery was associated with increased risk for dislocation (odds ratio 7.2, confidence interval 1.2 to 43.7, P = .032). ConclusionsIsolated bearing exchanges for instability following THA remained at high risk for subsequent instability. Conversion to dual mobility articulations did not reduce the risk of reoperation.

Metal artifact reduction sequence-MRI abnormalities in asymptomatic patients with dual-mobility hip prostheses.

Modular dual-mobility (DM) articulations are increasingly used during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS)-MRI abnormalities with serum metal ion levels in patients with DM articulations. A total of 45 patients (50 hips) with a modular DM articulation were included with mean follow-up of 3.7 years (SD 1.2). Enrolled patients with an asymptomatic, primary THA and DM articulation with over two years' follow-up underwent MARS-MRI. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels. Overall, two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels > 3.0 μg/l. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels < 1.0 μg/l. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels < 1.0 μg/l, while one (2.6%) had a cobalt level of 1.4 μg/l. One patient (2.2%) had a chromium level > 3.0 μg/l and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels > 5.0 μg/l without associated MARS-MRI abnormalities. Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic DM articulations occur infrequently (4.4%), but further assessment is necessary due to implant heterogeneity.

Dual Mobility Articulation in Total Hip Arthroplasty: Mixed Femoral and Acetabular Components are a Feasible Option

BackgroundThe utilization of a different manufacturer for the prosthetic femoral head and the polyethylene insert in dual mobility (DM) for total hip arthroplasty (THA) may be necessary, especially in the revision setting. However, there is no data in the literature about this application. This study evaluated the outcomes of mixed manufacturer components, with the hypothesis that there would be no difference in measured outcomes compared to matched components. MethodsThe DM articulations implanted during THA revision were retrospectively reviewed from 2011 to 2017. The study group was then stratified into 2 cohorts: matching components or mixed components. Of 130 hips included in the study with DM articulations with average follow-up of 7 years, 103 had mixed and 27 had matching manufacturer components. Rates of all cause reoperation and revision, intraprosthetic dislocation, dislocation, and aseptic loosening were compared using Chi-squared and Fisher’s exact test; survival analysis was also performed. ResultsMatched and mixed manufacturer implants had no significant difference between all cause reoperation (33 versus 25.2%), dislocation (14.8 versus 7.7%), and aseptic loosening (3.7 versus 3.9%), respectively. Higher rates of intraprosthetic dislocation (11 versus 0.97%) were observed in the matching component cohort. Survival analysis showed similar outcomes at 2, 5, and 10 years. ConclusionsMixed-component DM articulations show similar results compared to matching components. The off-label use of mixed manufacture DM articulation in THA is a feasible and safe option in the correct patient. Furthermore, when encountering a well-fixed femoral stem or acetabular shell, the use of a mixed component DM articulations may reduce the morbidity for the patient and prevent revision of all components.

Medium-term outcome of the Libra® cemented versus cementless stems in primary dual mobility total hip arthroplasty

IntroductionDespite the increasing use of cementless stems in total hip arthroplasty, the cemented stem has played a valuable role in the armamentarium of orthopedic surgeons. This study aims to compare two types of Libra® stems SERF, one cemented (Libra® C) and the other cementless hydroxyapatite coated (Libra® HA) that were conducted to analyze the medium-term outcome regarding their behavior and longevity.MethodsThis is a retrospective study for patients who received primary total hip arthroplasty with Dual Mobility (DM) articulation in the period between January 2014 to January 2020 with a minimum of two years follow-up. Two-hundred hips have been identified in 196 patients. One hundred forty-three Libra® cementless versus fifty-seven Libra cemented stems were implanted and the outcome of these stems is reported. All procedures were performed through the posterior approach and cemented stems were selected for elderly patients with wide medullary canals Dorr Type C. The indications for the index procedure were fractures, avascular necrosis, rheumatoid, and osteoarthritis. One hundred thirty-nine cementless DM cups were used while sixty-one hips had cemented Novae stick cups. Radiological evaluation for cup and stem positions, cement mantle, and radiolucent lines was performed, besides clinical function using the Harris Hip Score.ResultsThe average age of patients was 60 ± 14.8. At the latest review, none of the cemented stems was revised or awaiting revision. One cementless stem was revised because of cortical perforation. Five intraoperative fractures were observed in the cementless group, but none of them needed revision or affected the stem stability. Readmission to theatre occurred in four patients to evacuate hematoma in two, a reduction of dislocation in one, and grafting bone lysis in one.ConclusionCemented stems have an important role in osteoporotic patients with wide medullary canals with excellent outcomes and minimal risk of fracture.Level of evidenceLevel IV.

Single center evaluation of outcomes of modular dual mobility liners during revision total hip arthroplasty: A five-year follow-up

IntroductionRevision total hip arthroplasty (rTHA) is at increased risk for postoperative instability when compared to primary cases, which has been mitigated to some extent with the introduction of dual mobility (DM) reconstructions. These constructs were designed to lower dislocation rates and to improve impingement-free range of motion. As a follow-up to our prior institutional study, we expanded on a cohort of DM reconstructions compared to non-DM constructs. We examined a modular dual mobility system in rTHA to measure loosening of the acetabular component, as well as revision and dislocation rates in comparison to an historical cohort of single articulation prostheses.Materials/Methods: This retrospective cohort study from a single center included 254 patients who underwent rTHA with a dual mobility liner by three fellowship-trained surgeons between January 1, 2014 and December 1, 2019. This was a follow-up to an historical cohort of revisions performed with a single articulation prosthesis (n = 120) from the same surgeons performed between January 1, 2011 and December 23, 2013. The inclusion criteria included consecutively performed rTHAs that had a minimum follow-up of 2 years. We excluded patients who had femoral revisions and head/liner revisions only. The average follow-up in the dual mobility cohort and the single articulation cohort was 5 years (range, 2–10 years) and 2.5 years (range, 1.5–4.3 years), respectively. The primary outcomes were dislocation, aseptic loosening, and re-revision rates. Secondary outcomes were radiographic analyses of cup migration and osteolysis. ResultsThere were 4 out of 256 (1.6%) dislocations from the dual mobility cohort compared to 7 out of 120 (5.8%), P < 0.001 from the single articulation cohort. The rates of aseptic loosening were 3.2% (8 out of 254) and 4.2% (5 out of 120), P = 0.124, respectively, between the cohorts. The re-revision rate was 5.9% for the DM liners and 8.3% in the control cohort, P = 0.38. Radiographic analyses revealed no cup migration and osteolysis in any of the patients that had no dislocations. ConclusionThe dual mobility articulations in rTHA demonstrated improved results in terms of lower dislocations rates when compared to a single articulation prostheses. Our center uses these articulations for revisions and surgeons should consider the use of these bearings when performing rTHA.

METAL ARTIFACT REDUCTION SEQUENCE MRI ABNORMALITIES IN ASYMPTOMATIC PATIENTS WITH DUAL MOBILITY HIP PROSTHESES

Modular dual mobility (DM) articulations are increasingly utilized during total hip arthroplasty (THA). However, concerns remain regarding the metal liner modularity. This study aims to correlate metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) abnormalities with serum metal ion levels in patients with DM articulations.All patients with an asymptomatic, primary THA and DM articulation with &gt;2-year follow-up underwent MARS-MRI of the operative hip. Each patient had serum cobalt, chromium, and titanium levels drawn. Patient satisfaction, Oxford Hip Score, and Forgotten Joint Score-12 (FJS-12) were collected. Each MARS-MRI was independently reviewed by fellowship-trained musculoskeletal radiologists blinded to serum ion levels.Forty-five patients (50 hips) with a modular DM articulation were included with average follow-up of 3.7±1.2 years. Two patients (4.4%) had abnormal periprosthetic fluid collections on MARS-MRI with cobalt levels &gt;3.0 μg/L. Four patients (8.9%) had MARS-MRI findings consistent with greater trochanteric bursitis, all with cobalt levels &lt; 1.0 μg/L. A seventh patient had a periprosthetic fluid collection with normal ion levels. Of the 38 patients without MARS-MRI abnormalities, 37 (97.4%) had cobalt levels &lt;1.0 μg/L, while one (2.6%) had a cobalt level of 1.4 μg/L. One patient (2.2%) had a chromium level &gt;3.0 μg/L and a periprosthetic fluid collection. Of the 41 patients with titanium levels, five (12.2%) had titanium levels &gt;5.0 μg/L without associated MARS-MRI abnormalities.Periprosthetic fluid collections associated with elevated serum cobalt levels in patients with asymptomatic dual mobility articulations occur infrequently (4.4%), but further assessment of these patients is necessary.Level of Evidence: Level IV

Is Modular Dual Mobility Superior to Standard Bearings for Reducing Dislocation Risk after Primary Total Hip Arthroplasty? A Retrospective Comparative Multicenter Study.

Dual mobility (DM) has been proven to reduce dislocation risk after total hip arthroplasty (THA). In the last decade modular DM (modDM) constructs have been introduced to allow the use of DM articulation with standard cementless acetabular shells. However, clinical evidence of modDM effectiveness is still low in primary THA and concerns about implant-related complications are increasing. This retrospective comparative multicenter study is aimed to investigate if the dislocation rate after primary THA could be reduced with modDM in comparison to standard bearing (SB). 262 THAs were performed between 2017 and 2019, using SB (129 hips) or modDM (133) with the same cementless highly porous modular acetabular cup. Dislocations, complications and revisions were recorded and implant survival was analyzed. At 2.5-year mean follow-up, dislocation occurred in 4 hips (3.1%) within the SB group while intraprosthetic dislocation in 2 hips (1.5%) within the modDM group (p = 0.44). Implant survivals with revision due to dislocation were 95.2% and 95.9% at 4-year follow-up for SB and modDM, respectively (p = 0.50). modDM used in primary THA might reduce dislocation rate in comparison to SB, even in high-risk patients, however, caution is advocated due to specific intraprosthetic dislocation.

Dual Mobility Articulation in Revision Total Hip Arthroplasty: An American Joint Replacement Registry Analysis of Patients Aged 65 Years and Older

BackgroundIncreasingly, dual mobility (DM) articulations have been used in revision total hip arthroplasty (THA), which may prevent postoperative hip instability. The purpose of this study was to report on outcomes of DM implants used in revision THA from the American Joint Replacement Registry (AJRR). MethodsRevision THA cases performed between 2012 and 2018 Medicare were eligible and categorized by 3 articulations: DM, ≤32 mm, and ≥36 mm femoral heads. The AJRR-sourced revision THA cases were linked to Centers for Medicare and Medicaid Services (CMS) claims data to supplement (re)revision cases not captured in the AJRR. Patient and hospital characteristics were described and modeled as covariates. Using multivariable Cox proportional hazard models, considering competing risk of mortalities, hazard ratios were estimated for all-cause re-revision and re-revision for instability. Of 20,728 revision THAs, 3,043 (14.7%) received a DM, 6,565 (31.7%) a ≤32 mm head, and 11,120 (53.6%) a ≥36 mm head. ResultsAt 8-year follow-up, the cumulative all-cause re-revision rate for ≤32 mm heads was 21.9% (95%-confidence interval (CI) 20.2%-23.7%) and significantly (P < .0001) higher than DM (16.5%, 95%-CI 15.0%-18.2%) and ≥36 mm heads (15.2%, 95%-CI 14.2%-16.3%). At 8-year follow-up, ≥36 heads had significantly (P < .0001) lower hazard of re-revision for instability (3.3%, 95%-CI 2.9%-3.7%) while the DM (5.4%, 95%-CI 4.5%-6.5%) and ≤32 mm groups (8.6%, 95%-CI 7.7%-9.6%) had higher rates. ConclusionThe DM bearings are associated with lower rates of revision for instability compared to patients who had ≤32 mm heads and higher revision rates for ≥36 mm heads. These results may be biased due to unidentified covariates associated with implant selection.

Incidence of Instability Following Primary Total Hip Arthroplasty Continues to Decline in the Medicare Population

BackgroundInstability has been the primary cause of failure following primary total hip arthroplasty (THA) leading to revision hip surgery. The purpose of this study was to determine if instability rates have further declined following advances in primary THA, including dual mobility articulations, direct anterior approaches, advanced technologies, and improved knowledge of the hip-spine relationships. MethodsUsing the 5% Medicare Part B claims data from 1999 to 2019, we identified 81,573 patients who underwent primary THA for osteoarthritis. Patients who experienced instability at 3 months, 6 months, 1 year, and 2 years were identified. Multivariate cox regression analyses evaluated the effect of patient and procedure characteristics on the risk of instability. ResultsInstability at 1 year following primary THA declined from approximately 4% in 2000 to 2.3% in 2010 and 1.6% in 2018. The leading cause of revision surgery was infection (18.6%), followed by periprosthetic fracture (14%), mechanical loosening (11.5%), and instability (9.4%). High-risk groups for instability continue to include increased age, higher Charlson index, obesity, lumbar spine pathology, and neurocognitive disorders. ConclusionInstability is no longer the leading etiology of failure following primary THA with a decline of approximately 40% over the past decade. Infection, periprosthetic fracture, mechanical loosening, and then instability are now the leading causes of failure. Multiple factors may play a role in the decline of instability, including increased use of dual mobility articulations, direct anterior approaches, improved knowledge of the hip-spine relationships, and use of advanced technologies.

Modular dual mobility articulation in primary and revision hip arthroplasty: lights and shadows

PurposeThe use of dual mobility cups in total hip arthroplasty has gained popularity in light of the fact it enables to reduce dislocation through increased jumping distance (JD) and impingement-free arc of movement. Modular Dual Mobility Cup (modular DMC) systems have been recently introduced to enable the use of dual mobility cups with standard metal-backed shells. The objective of this study was twofold: calculate the JD for each modular DMC system and conduct a systematic literature review to report clinical outcomes and reasons for failure of this construct.MethodsThe JD was calculated using the Sariali formula: JD = 2Rsin [(π/2 − Ψ − arcsin (offset/R))/2]. A qualitative systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive search for English and French articles between January 2000 and July 2020 was run on PubMed, EMBASE, Google Scholar, and Scopus with the primary objective of finding articles about modular DMC systems.ResultsWe identified eight 8 different manufacturers of modular DMC systems and 327 publications on the subject. After screening for duplicates and eligibility, we identified 229 publications: 206 articles were excluded because they contained no reports on modular DMC systems, whereas other three were not included because they focused on biomechanical aspects. Among the 11 included articles, 2 were prospective case series, 9 were retrospective case series. True dislocation occurred in 25 cases (0.9%), and six of them were solved by closed reduction without necessity of revision, while all 5 intraprosthetic dislocations were operated.ConclusionsModular DMCs are a valid method to deal with complex THA instability, with good clinical and patient-reported outcomes, low complication rates, and low revision rates at early follow-up. We would advise cautious optimism on the role of modular DMC implants, as it seems safer to use ceramic instead of metallic heads whenever possible to avoid the increase cobalt and chromium trace ion serum levels.

Outcomes of total hip arthroplasty with a standard prosthesis for the affected hip in patients with poliomyelitis sequelae: a mid-term retrospective follow-up study

IntroductionTotal hip arthroplasty for poliomyelitis sequelae could be a technical challenge due to the higher risk for prosthetic dislocation and degenerative changes in the affected limbs. This study aimed to analyse the mid-term outcomes of primary total hip arthroplasty on the affected hip with standard prosthesis.Materials and MethodsFrom January 2008 to January 2018, 32 patients with poliomyelitis sequelae underwent total hip arthroplasty on the affected hip with standard prosthesis. Clinical and radiographical outcomes, complications, and prosthesis survival rates were evaluated.ResultsAfter a mean follow-up of 7.9 (4.4–13.1) years, the Harris Hip Score, University of California Los Angeles activity level rating, and 12-item Short Form Health Survey Questionnaire scale score significantly improved. The abduction and flexion motions of the hip joint improved dramatically, and the visual analogue scale pain score decreased significantly. The leg length discrepancy was effectively corrected. During the follow-up, one patient experienced prosthetic dislocation, one underwent revision surgery due to acetabular component loosening, two had osteolysis, four had heterotopic ossification, two experienced transient sciatic nerve palsy, and one had intermuscular vein thrombosis. The prosthesis survival rate was 96.9% at 5 years postoperatively. No periprosthetic infection occurred.ConclusionTotal hip arthroplasty with standard prosthesis could be an effective treatment for hip arthropathy on the affected hip of patients with poliomyelitis sequelae, resulting in good clinical outcomes and few complications. Constrained liner and dual mobility articulation are not recommended unless the hip muscle strength of the abductor is < III.

What Is the Risk of Dislocation and Revision in Proximal Femoral Replacement with Dual-mobility Articulation After Two-stage Revision for Periprosthetic Hip Infection?

Dislocation is a major complication of revision THA after two-stage exchange for periprosthetic joint infection (PJI). The likelihood of dislocation can be particularly high if megaprosthetic proximal femoral replacement (PFR) has been performed during a second-stage reimplantation. Dual-mobility acetabular components are an established way of reducing the instability risk in revision THA; however, the likelihood of dislocation for dual-mobility reconstructions in the setting of a two-stage PFR has not been studied systematically, although patients with these reconstructions might be at an increased risk. (1) What is the risk of dislocation and revision for dislocation in patients who underwent PFR with a dual-mobility acetabular component as part of two-stage exchange for hip PJI? (2) What is the risk of all-cause implant revision and what other procedures were performed (apart from revision for a dislocation) in these patients? (3) What potential patient-related and procedure-related factors are associated with dislocation? This was a retrospective study from a single academic center including procedures performed between 2010 and 2017. During the study period, 220 patients underwent two-stage revision for chronic hip PJI. Two-stage revision was the approach of choice for chronic infections, and we did not perform single-stage revisions for this indication during the study period. Thirty-three percent (73 of 220) of patients underwent second-stage reconstruction with a single-design, modular, megaprosthetic PFR because of femoral bone loss, using a cemented stem. A cemented dual-mobility cup was the approach of choice for acetabular reconstruction in the presence of a PFR; however, 4% (three of 73) were reconstructed with a bipolar hemiarthroplasty to salvage an infected saddle prosthesis, leaving 70 patients with a dual-mobility acetabular component and a PFR (84% [59 of 70]) or total femoral replacement (16% [11 of 70]). We used two similar designs of an unconstrained cemented dual-mobility cup during the study period. The median (interquartile range) patient age was 73 years (63 to 79 years), and 60% (42 of 70) of patients were women. The mean follow-up period was 50 ± 25 months with a minimum follow-up of 24 months for patients who did not undergo revision surgery or died (during the study period, 10% [seven of 70] died before 2 years). We recorded patient-related and surgery-related details from the electronic patient records and investigated all revision procedures performed until December 2021. Patients who underwent closed reduction for dislocation were included. Radiographic measurements of cup positioning were performed using supine AP radiographs obtained within the first 2 weeks after surgery using an established digital method. We calculated the risk for revision and dislocation using a competing-risk analysis with death as a competing event, providing 95% confidence intervals. Differences in dislocation and revision risks were assessed with Fine and Gray models providing subhazard ratios. All p values were two sided and the p value for significance was set at 0.05. The risk of dislocation (using a competing-risks survivorship estimator) was 17% (95% CI 9% to 32%) at 5 years, and the risk of revision for dislocation was 12% (95% CI 5% to 24%) at 5 years among patients treated with dual-mobility acetabular components as part of a two-stage revision for PJI of the hip. The risk of all-cause implant revision (using a competing-risk estimator, except for dislocation) was 20% (95% CI 12% to 33%) after 5 years. Twenty-three percent (16 of 70) of patients underwent revision surgery for reinfection and 3% (two of 70) of patients underwent stem exchange for a traumatic periprosthetic fracture. No patients underwent revision for aseptic loosening. We found no differences in patient-related and procedure-related factors or acetabular component positioning for patients with dislocation with the numbers available; however, patients with total femoral replacements had a higher likelihood of dislocation (subhazard ratio 3.9 [95% CI 1.1 to 13.3]; p = 0.03) and revision for a dislocation (subhazard ratio 4.4 [95% CI 1 to 18.5]; p = 0.04) than those who received PFR. Although dual-mobility bearings might be an intuitive potential choice to reduce the dislocation risk in revision THA, there is a considerable dislocation risk for PFR after two-stage surgery for PJI, particularly in patients with total femoral replacements. Although the use of an additional constraint might appear tempting, published results vary tremendously, and future studies should compare the performance of tripolar constrained implants to that of unconstrained dual-mobility cups in patients with PFR to reduce the risk of instability. Level III, therapeutic study.

Is Outcome of Total Hip Arthroplasty for Hip Fracture Inferior to That of Arthritis in a Contemporary Arthroplasty Practice?

BackgroundOutcome of total hip arthroplasty (THA) for femoral neck fractures (FNF) has been associated with higher complication rates. However, THA for FNF is not always performed by arthroplasty surgeons. This study aimed to compare THA outcomes for FNF to osteoarthritis (OA). In doing so, we described contemporary THA failure modes for FNF performed by arthroplasty surgeons. MethodsThis was a retrospective, multisurgeon study from an academic center. Of FNFs treated between 2010 and 2020, 177 received THA by an arthroplasty surgeon [mean age 67 years (range, 42 to 97), sex: 64.4% women]. These were matched (1:2) for age and sex with 354 THAs performed for hip OA, by the same surgeons. No dual-mobilities were used. Outcomes included radiologic measurements (inclination/anteversion and leg length), mortality, complications, reoperation rates and patient-reported outcomes including Oxford Hip Score. ResultsPostoperative mean leg-length difference was 0 mm (range, −10 to −10 mm), with a mean cup inclination and anteversion of 41 and 26°, respectively. There was no difference in radiological measurements between FNF and OA patients (P = .3). At a 5-year follow-up, mortality rate was significantly higher in the FNF-THA group compared to the OA-THA group (15.3 versus 1.1%; P < .001). There was no difference in complications (7.3 versus 4.2%; P = .098) or reoperation rates (5.1 versus 2.9%; P = .142) between the groups. Dislocation rate was 1.7%. Oxford Hip Score at the final follow-up was similar [43.7 points (range, 10 to 48) versus 43.6 points (range, 10 to 48); P = .030]. ConclusionTHA for the treatment of FNF is a reliable option and is associated with satisfactory outcomes. Instability was not a common reason of failure, despite not using dual-mobility articulations in this at-risk population. This is likely due to THAs being performed by the arthroplasty staff. When patients live beyond 2 years, similar clinical and radiographic outcomes with low rates of revision can be expected compared to elective THA for OA. Level of evidenceIII, case-control study.

Failure of a Highly Cross-Linked Polyethylene Liner After Spine Fusion.

A 73-year-old woman, 11 years after total hip arthroplasty and 2 years after a multilevel lumbar spine fusion, presented with a 2-month history of anterior hip and gluteal pain. She was diagnosed with an acetabular liner fracture that occurred through the high wall, likely related to repetitive impingement on the neck of the femoral implant, as notable burnishing was observed on the explanted femoral head. The acetabulum was successfully revised to a dual-mobility articulation. Spinal fusion after total hip arthroplasty can alter the acetabular implant position and was seen in our patient whose previously functional high-walled liner failed. Surgeons may consider alternative techniques, including a change in acetabular implant's anteversion to mitigate the need for a high-walled liner or the use of a dual-mobility bearing.

Large Femoral Heads and Select Dual-Mobility Bearings Are Associated With Reduced Instability in Contemporary Posterior Approach Total Hip Arthroplasty

BackgroundPostoperative dislocation is considered the main drawback of posterior approach total hip arthroplasty (THA). Thinner highly cross-linked polyethylene and dual-mobility bearings allow maximizing femoral head diameter per a given cup size. This study evaluated dislocation rates as large femoral head bearings were introduced into a practice over an 11-year period. MethodsA total of 1,511 consecutive primary THAs were retrospectively reviewed. Demographics, implant sizes, femoral head-acetabular cup ratio, and dislocation status were collected from the electronic medical record. Data were evaluated using time series analysis techniques as larger femoral heads, thinner polyethylene liners, and dual-mobility bearings were introduced. The cohort was 57% women with mean age and body mass index of 62 years (range, 13 to 93) and 31 kg/m2 (range, 13 to 54), respectively. ResultsThe overall dislocation rate was 0.98%. Use of femoral head sizes ≥ 40 millimeters increased from 4% in the years 2010 to 2016 to 51% in the years 2017 to 2021, correlating with a 50% reduction in dislocation rate from 1.4% to 0.7% (P = .279). Also, no dislocations occurred in patients who had dual-mobility bearings or ≥ 40-millimeter femoral heads (P = .007). Twelve of 14 dislocations occurred in cases with head-cup ratio < 0.7 (P = .013). Thirteen of 14 dislocations were in women (P = .005). ConclusionMaximizing the femoral head diameter per given cup size correlated with a decrease in dislocation rate in modern posterior approach THA. Furthermore, these results suggest that dual-mobility articulations should be reserved for high-risk patients or patients in whom a 40-millimeter femoral head is not possible. Level of EvidenceIV–consecutive case series; no control group.

Is the Revision Rate for Femoral Neck Fracture Lower for Total Hip Arthroplasty Than for Hemiarthroplasty?: A Comparison of Registry Data for Contemporary Surgical Options.

When arthroplasty is indicated for a femoral neck fracture (FNF), it is unclear whether total hip arthroplasty (THA) or hemiarthroplasty (HA) is best. This study compares data from the Australian Orthopaedic Association National Joint Replacement Registry using contemporary surgical options. Patients from 60 to 85 years old who were treated with arthroplasty for FNF, between September 1999 and December 2019, were included if the femoral stems were cemented. Only THAs with femoral heads of ≥36 mm or dual-mobility articulations were included. Patients who had monoblock HA were excluded. Rates of revision for all aseptic failures and dislocation were compared. Competing risks of revision and death were considered using the cumulative incidence function. Subdistribution hazard ratios (HRs) for revision or death from a Fine-Gray regression model were used to compare THA and HA. Interactions of procedure with age group and sex were considered. Secondary analysis adjusting for body mass index (BMI) and American Society of Anesthesiologists (ASA) classification was also considered. There were 4,551 THA and 29,714 HA procedures included. The rate of revision for THA was lower for women from 60 to 69 years old (HR = 0.58 [95% confidence interval (CI), 0.39 to 0.85]) and from 70 to 74 years old (HR = 0.65 [95% CI, 0.43 to 0.98]) compared with HA. However, women from 80 to 85 years old (HR = 1.56 [95% CI, 1.03 to 2.35]) and men from 75 to 79 years old (HR = 1.61 [95% CI, 1.05 to 2.46]) and 80 to 85 years old (HR = 2.73 [95% CI, 1.89 to 3.95]) had an increased rate of revision when THA was undertaken compared with HA. There was no difference in the rate of revision for dislocation between THA and HA for either sex or age categories. When contemporary surgical options for FNF are used, there is a benefit with respect to revision outcomes for THA in women who are <75 years old and a benefit for HA in women who are ≥80 years old and men who are ≥75 years old. There is no difference in dislocation rates. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.