Cemented Dual Mobility Cup Research Articles

Cemented dual-mobility constructs in uncemented revision acetabular components.

Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct. We identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented cups designed for liner cementing (n = 48; 74%) or retained (n = 17; 26%) acetabular components. Median outer head diameter was 42 mm. Mean age was 69 years (SD 11), mean BMI was 32 kg/m2 (SD 8), and 52% (n = 34) were female. Survival was assessed using Kaplan-Meier methods. Mean follow-up was two years (SD 0.97). There were nine cemented DM cup revisions: three for periprosthetic joint infection, three for acetabular aseptic loosening from bone, two for dislocation, and one for a broken cup-cage construct. The two-year survivals free of aseptic DM revision and dislocation were both 92%. There were five postoperative dislocations, all in patients with prior dislocation or abductor deficiency. On radiological review, the DM cup remained well-fixed at the cemented interface in all but one case. While dislocation was not eliminated in this series of complex revision THAs, this technique allowed for maximization of femoral head diameter and optimization of effective acetabular component position during cementing. Of note, there was only one failure at the cemented interface.

Use of dual mobility cup cemented into a tantalum acetabular shell for hip revision with large bone loss can decrease dislocation risk without increasing the risk of mechanical failure

BackgroundPorous tantalum components and augments have demonstrated short to midterm fixation stability in acetabular total hip arthroplasty (THA) revision but do not offer a novel option to decrease the postoperative dislocation rate. Recently, dual mobility (DM) cups have gained interest to decrease the prevalence of recurrent hip instability after revision hip arthroplasty, but this issue was not confirmed combined with use of tantalum reconstruction devices. Therefore, we did a retrospective study aiming to: (1) evaluate at a 5-year minimum follow-up period the dislocation rate (and other intra- and postoperative complications), (2) assess radiographic results specifically looking at osseointegration and restoration of the hip center, (3) and also clinical results in a cohort of patients who underwent complex acetabular reconstruction with trabecular metal revision components associated with a cemented DM socket. HypothesisUsing a DM socket cemented in porous tantalum components can reach the low risk of hip dislocation reported with DM components in revision setting without increasing the risk of a mechanical failure. MethodsA cross-sectional study identified 174 THA revision including an acetabular revision. Were excluded 118 revisions with acetabular defects Type 1, 2a or 2B according to Paprosky's classification, as well as 18 hips revised without a dual mobility and 3 patients (3 hips) lost to follow-up. Were thus included in this study 35 hips (35 patients) implanted with uncemented total hip arthroplasty revision using both trabecular metal acetabular cup-cage reconstruction and a cemented DM cup. Seven hips were classified Paprosky types 2C, 15 type 3A and 13 types 3B. Patients were followed with clinical and radiological evaluation regarding dislocation rate, infection, reoperation or re-revision, osseointegration and restoration of the hip center, and functional results according to the Harris hip score and psoas impingement presence. ResultsAt a mean follow-up of 8.1±1.8 years (5.1–12.6), one dislocation was recorded, and one acute deep infection. No patient required a cup re-revision for septic or aseptic loosening. The survivorship at 8years regarding revision for any cause as an endpoint was 96.5% (CI95%: 92–99). Osseointegration of TM implants was analyzed and found no acetabular migration at the last follow-up in the cohort. The mean hip center position was optimized from 48±7mm (37–58) to 34±5mm (29–39) vertically and from 26±5mm (–18–36) to 24±8mm (7–31) horizontally without reaching significance (p=0.1). On the last follow-up X-rays, the mean acetabular inclination was 47̊±9̊ (32̊–61̊). According to the criteria of Hirakawa, 97.1% (34/35) of the hip centers were restored. One cup (2.9%) was more than 5mm proximally from the hip center, and none more than 10mm. Clinical results assessed a Harris Hip Score improved from 36±17 (23–62) preoperatively to 82±15 (69–93) at last follow-up (p<0.0001). Two patients (2/35, 5.7%) complained of psoas impingement. ConclusionThis study suggests effectiveness of DM cups in association with a tantalum-made acetabular shell for reconstruction of large bone defect in THRs for both solving postoperative instability and aseptic loosening without increasing the re-revision rate for any reason in a midterm follow-up. Level of evidenceIV; observational study.

Removing Cemented Dual Mobility Liners From Acetabular Components: A Technical Tip for a Challenging Surgical Problem.

Dislocation remains the leading cause of failure following revision total hip arthroplasty. Dual mobility (DM) constructs, including monoblock cups designed for cementation, reduce but do not eliminate this risk. Cemented DM constructs offer several unique advantages in revision total hip arthroplasty, and as such, they have gained popularity. Despite their advantages, a portion of these implants will require revision for infection or recurrent dislocation. Removal of a cemented DM cup presents numerous challenges, and there is no effective published technique. Here, we present an effective technique for the safe removal of one design of cemented DM cup.

DUAL MOBILITY CUP CEMENTED INTO POROUS TRABECULAR METAL SHELL DURING REVISION TOTAL HIP ARTHROPLASTY

Revision total hip arthroplasty (RTHA) is a challenging procedure when we speak about acetabular defects and recurrent instability. There are multiple reasons like the number of previous revisions, implant position, bone quality, patient characteristics and etc. Managing acetabular defects with porous trabecular metal augments has excellent survivorship, but when addressing instability, there are some unsolved issues. Management options include the use of large femoral heads, constrained acetabular liners, and dual mobility cups (DMC). These cups have increased jump distance and reduced likelihood of dislocation while not relying on locking mechanisms, therefore are the preferred option in RTHA. We present single-center series of 13 patients undergoing revision THA with a specific DMC cemented into a newly implanted or well-fixed trabecular metal (TM) revision shell. All patients underwent cementation of a single specific cemented DMC design (Novae Stick, SERF, Decines, France) in a Trabecular Metal Revision Shell (Zimmer Biomet, Warsaw, IN, US). The mean follow-up is 15,2 months, and there were no dislocations of the implanted DM cups. The mean HHS improved significantly from 35.9 (range 15–80) preoperatively to 80.1 (range 64-93) postoperatively (p = 0.001). The results of this small clinical series demonstrate that cementing a DMC in a well-fixed TM revision shell leads to no dislocation or dissociation of the cement interface and acetabular construct loosening in the short term.

What is the rate of successful closed reduction of dislocated dual mobility cups following complex revision hip arthroplasty?

The aim of this study was to assess the difference in success rates of closed reduction in septic and aseptic revision total hip arthroplasty (THA) performed with a dual mobility (DM) implant. Our objective was to answer the following questions: (1) Is there a difference in success rates of closed reduction between septic and aseptic revision THA with a DM implant? (2) Is closed or open reduction more successful in preventing re-dislocation? Between January 2009 and October 2021, 924 revisions were performed with a DM implant. All patients presenting to our institution with a dislocation following septic or aseptic revision THA using a cemented DM cup were included in this study. We analyzed 106 cases of dislocation in 74 patients. For all patients, we collected reason for revision, and classified index surgery as septic or aseptic. Overall, 106 dislocations occurred (106/924, 11.5%). Thirty-nine cases (52.7%) had a dislocation after a septic exchange THA, while in 35 patients (47.3%), a dislocation occurred after an aseptic rTHA. In 29 patients (39.2%), successful closed reduction under general anesthesia was feasible, while the majority of cases required open reduction. In 31 of these patients (67.4%), open reduction was combined with a revision arthroplasty. In case of DM cupdislocation, there is a low success rate of closed reduction. To prevent re-dislocation, total revision leads to a significantly reduced risk compared to open or closed reductionalone. Careful X-rayanalysis for a halo sign showingintra-prosthetic DM cupdislocation is mandatory to avoid futile reduction attempts. 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.

Cementless augmented versus cemented Dual Mobility cups: medium-term outcome of case series with a control group

BackgroundPost-operative dislocation and reconstruction of acetabular defects are two challenging topics in revision Total Hip Arthroplasty (rTHA). Cemented Dual Mobility (DM) cups on top of Kerboull Cross and bone graft have been successfully employed to overcome these challenges. The cementless augmented DM cups were recently introduced. In this study medium term results of the augmented cementless DM Coptos cups are reported and compared to the established technique of cemented DM cups and Kerboull plate.Material and methodsThis is a retrospective analysis of data collected on patients who received rTHA using DM cups in the period between June 2015 and September 2020. Two groups of patients were identified. The first group received cementless augmented DM-cups (NOVAE® Coptos TH–SERF) (Coptos TH cup group). The second comparable group who had Kerboull ring (KE ring group) and cemented DM cups (NOVAE® STICK). Demographic data, surgical technique, functional and radiological outcome as well as complications during the follow-up visits are reported.ResultsForty-two patients with a mean age at the time of revision 48.8 ± 13.6 years. 29 patients received Coptos TH DM-cup, while 13 patients had Bone Graft (BG), KE ring and cemented DM cups for acetabular reconstruction. Acetabular defects were Paprosky types IIB and IIC in 31 patients and IIIA and B in 11 patients. The follow-up was 52.8 ± 21 months (mean ± STD); and the mean Harris Hip Score (HHS) at last visit was 91 ± 5. Good stability of all cups was reported. Full integration of the impaction graft was observed in 94% of the Coptos and 92% of the KE groups. One of the Coptos cups was readjusted and one case of single dislocation was recorded in the KE group. None of the DM cups in both groups was revised or awaiting revision.ConclusionCoptos TH cups achieve similar results to the cemented DM on KE ring at the medium term but long term outcome remains to be seen.

Is Cemented Dual-Mobility Cup a Reliable Option in Primary and Revision Total Hip Arthroplasty: A Systematic Review.

Background: Instability is a common complication following total hip arthroplasty (THA). The dual mobility cup (DMC) allows a reduction in the dislocation rate. The goal of this systematic review was to clarify the different uses and outcomes according to the indications of the cemented DMC (C-DMC). Methods: A systematic review was performed using the keywords "Cemented Dual Mobility Cup" or "Cemented Tripolar Cup" without a publication year limit. Of the 465 studies identified, only 56 were eligible for the study. Results: The overall number of C-DMC was 3452 in 3426 patients. The mean follow-up was 45.9 months (range 12-98.4). In most of the cases (74.5%) C-DMC was used in a revision setting. In 57.5% DMC was cemented directly into the bone, in 39.6% into an acetabular reinforcement and in 3.2% into a pre-existing cup. The overall dislocation rate was 2.9%. The most frequent postoperative complications were periprosthetic infections (2%); aseptic loosening (1.1%) and mechanical failure (0.5%). The overall revision rate was 4.4%. The average survival rate of C-DMC at the last follow-up was 93.5%. Conclusions: C-DMC represents an effective treatment option to limit the risk of dislocations and complications for both primary and revision surgery. C-DMC has good clinical outcomes and a low complication rate.

Direct Cementation of Dual Mobility Cups Into the Bony Acetabulum in Primary Total Hip Arthroplasty: Clinical and Radiographic Outcomes at a Minimum 5-Year Follow-Up

BackgroundCemented dual mobility cups (DMCs) are commonly used in combination with acetabular reinforcement devices. Indeed, according to literature, direct cementation of metal-backed acetabular components into the bony acetabulum remains controversial as this technique is potentially associated with increased rates of aseptic loosening. Therefore, this study aimed to evaluate the clinical and radiographic outcomes of DMC cemented into the bony acetabulum in primary total hip arthroplasty (THA). MethodsA total of 49 THA (48 patients, mean age 78 years [range, 51 to 91]) performed with direct cementation of a DMC into the bony acetabulum were prospectively included in our total joint registry and retrospectively reviewed. The clinical outcome was assessed using the Harris hip score (HHS). The radiographic outcome included measurement of component positioning and occurrence and progression of demarcation around the cemented DMC. Complications were reported with a particular attention to cemented fixation failure and aseptic loosening. ResultsAt a 7-year mean follow-up (range, 5 to 8), the pre-to postoperative HHS improved from 47 (range, 30 to 58) to 92 points (range, 80 to 98) (P < .01). Nonprogressive and focalized demarcations were observed in 7 THA (14%). Importantly, no progressive demarcation or DMC aseptic loosening was observed. ConclusionDirect cementation of DMC into the bony acetabulum ensured a stable fixation with no progressive demarcation or aseptic loosening at midterm follow-up. Therefore, this technique can be selectively considered in primary THA, especially in elderly or frail patients to avoid potential mechanical failure of press-fit fixation due to altered bone quality or additional morbidity related to the use of acetabular reinforcement devices.

Major acetabular defects: outcomes of first revision total hip arthroplasty using Kerboull cross-plate with allograft and cemented dual mobility cup at a maximum follow-up of fourteen years.

The use of dual mobility cups (DMC) has been shown to reduce hip instability after revision surgery. For severe acetabular bone loss, reconstruction with a Kerboull cross-plate and bone allograft would contribute to restoring native hip position and bone stock. Only two papers reported on the combination of Kerboull cross-plate with bone allograft and cemented DMC in revision total hip arthroplasty (THA). This is a monocentric retrospective study (28 cases) of first-time revision THA using such a construct in American Association of Orthopaedic Surgeons (AAOS) grade III and IV acetabular bone defect. Detailed demographic, clinical and radiographic results were recorded and evaluated. With a mean follow-up of six ± 3.63years, no case of instability was reported. The modified Harris Hip Score (mHHS) was 88.4 ± 10.1. No hook fracture or mechanical failure was observed. Non-progressive radiolucent lines were recorded. Osteointegration of the allografts was observed in all cases with a mean Grodet score of 7.9 ± 0.97. In first revision THA, the use of a Kerboull cross-plate with allograft and a cemented DMC in AAOS grade III and IV acetabular bone defects demonstrated excellent clinical and radiological outcomes with no recorded cases of dislocation or mechanical failure.

Dual mobility cup as a treatment of displaced femoral neck fractures in elderly

Background The main goal in the treatment of femoral neck fractures in the elderly is to enable early mobilization. Hemiarthroplasty is considered the gold standard line of treatment. In the past decade, total hip replacement (THR) was introduced to the orthopedic community with the advantage of better pain relief and functional outcome. However, the reported dislocation rates after THR in femoral neck fractures remained higher than the rates after hemiarthroplasty. Nowadays, there is renewed interest in dual mobility cups to solve the problems of hip instabilities for various reasons. Dual mobility cups aim to decrease the dislocation rate by associating two articular surfaces: one with a larger diameter situated between a metallic cup and a polyethylene insert, thus utilizing the concept of a large head size to reduce dislocation, and the other one with a smaller diameter situated between the femoral head and the retentive polyethylene insert to achieve more mobility. The authors believe that the results of the dual mobility concept after femoral neck fractures are under-reported, with few papers discussing the outcome specifically in the Egyptian population. Aim This study was carried out to assess the dislocation rate and clinical results for cemented THR with a dual mobility cup as the treatment of femoral neck fractures in elderly patients, after a minimum period of 1 year. Settings and design A prospective case series study was carried out at El Hadara University Hospital, Alexandria University. Patients and methods This study included 31 patients (32 hips) with displaced femoral neck fractures who were admitted to El Hadara University Hospital, Alexandria, Egypt. Their mean age was 66.6±6.3 years. There were 15 females and 16 males. All the patients were treated using a cemented dual mobility cup for THR using the standard posterior approach. Functional assessment was performed using the Harris hip score (HHS) with the assistance of physiotherapists to avoid bias. Results No dislocations were encountered in this series over 1 year of follow-up. The mean operative time was 136.9 min. The average blood loss was 756.3 ml. The mean HHS improved over the follow-up period from 80.3±7.9 (95% confidence interval: 74–86) at 12 weeks to an average of 92.6±11.1 (95% confidence interval: 88.7–96.5) at the 1-year follow-up. This increase in HHS was not statistically significant (P=0.143). Conclusions Dual mobility cup THR is a good method for the treatment of displaced femoral neck fractures in the elderly as it provides good stability, pain relief, and good function.

Cemented Dual Mobility Cup for Primary Total Hip Arthroplasty in Elder Patients with High-Risk Instability.

Several studies have shown that double mobility (DM) cups reduce postoperative dislocations. Does the cemented dual mobility cup reduce dislocations in a specific cohort of elder patients with a high dislocation risk? Our hypothesis is that this implant is optimal for elder patients because it reduces early dislocation. We have retrospectively reviewed elder patients who underwent total hip arthroplasty (THA) with cemented double mobility cup between March 2009 and January 2018. The inclusion criteria were patients (>75 years) who were operated on for primary THA (osteoarthritis or necrosis) with a cemented dual mobility cup and a high-risk instability (at least two patient-dependent risk factors for instability). The exclusion criteria were revision surgeries or hip fracture. In all the cases, the same surgical approach was performed with a Watson Jones modified approach in supine position. We have collected demographic data, instability risk factors. Patients were classified using the Devane’s score, Merle d’Aubigné score and the patient’s likelihood of falling with the Morse Fall Scale. Surgical and follow-up complications were collected from their medical history. Sixty-eight arthroplasties (68 patients) were included in the study. The median age was 81.7 years (SD 6.4), and the American Society of Anesthesiologists (ASA) score showed a distribution: II 27.94%, III 63.24% and IV 8.82%. Devane’s score was less than five in all of the cases. At least two patient-dependent risk factors for instability (87% had three or more) were present in each case. The median follow-up time was 49.04 months (SD 22.6). Complications observed were two cases of infection and one case of aseptic loosening at 15 months which required revision surgery. We did not observe any prosthetic dislocation. The cemented dual mobility cup is an excellent surgical option on primary total hip arthroplasties for elder patients with high-risk instability.

Cementation of a Dual Mobility Cup Into an Existing Well-Fixed Metal Shell: A Reliable Option to Manage Wear-Related Recurrent Dislocation in Patients With High Surgical Risk

BackgroundDuring revision total hip arthroplasty (THA), the “double-socket” technique has been proposed as a straightforward solution in order to reduce the overall perioperative morbidity in patients with high surgical risk. However, the option of cementing a dual mobility cup into an existing well-fixed metal shell was sparsely reported. Therefore, this study aimed to evaluate the outcome of a “double-socket” technique performed with a cemented dual mobility cup in revision THA for late instability. MethodsTwenty-eight revision THAs (28 patients) were performed for wear-related recurrent dislocation using a “double-socket” technique with a cemented dual mobility cup and retrospectively reviewed. The age at revision averaged 82 years (range 74-93). According to the American Society of Anesthesiologists (ASA) physical status classification, 12 patients (43%) were ASA II and 16 patients (57%) were ASA III before revision. ResultsAt a mean follow-up of 3.5 years (range 2-5), the mean preoperative to postoperative functional outcome improved significantly (P < .01). The mean operative time was 107 minutes (range 75-140). The mean intraoperative bleeding was 200 mL (range 110-420). No postoperative complication, reoperation, or re-revision was reported. Importantly, no dislocation, dissociation of the cemented dual mobility cup construct, or aseptic loosening of the retained metal shell was observed. ConclusionThe “double-socket” technique with a dual mobility cup cemented into an existing well-fixed and well-positioned metal shell ensured a straightforward and blood-sparing revision technique that was efficient to restore stability and provide a secure acetabular construct in frail patients with high surgical risk and/or older than their natural life expectancy.

Comparison of functional outcome of cemented total hip replacement versus cemented dual-mobility cup total hip replacement for the management of displaced femoral neck fractures in the active elderly patients.

Current guidelines recommend treating displaced femoral neck fractures with a total hip replacement in fit and active elderly patients. Dislocation remains the main complication. Dual-mobility cup (DMC) hip replacements maybe a solution to decrease dislocation, with the benefit of increasing stability, achieving better range of motion and functional outcomes. This is a prospective randomised controlled trial which included 62 patients with Garden III and IV femoral neck fractures. The mean age was 67.2 years. 30 males and 32 females were included, randomised and allocated to 2 treatment groups; a cemented DMC replacement group, or a cemented 32-mm head total hip replacement (THR). The posterior approach was used in all patients. Postoperative functional outcome was assessed using Harris Hip Score (HHS). Health-related quality of life (HRQoL) was assessed using the SF-36 questionnaire. The mean HHS for the DMC group at 4, 6 and 12 months were higher than mean HHS scores for the THR group (p < 0.001). The range of motion at 1 year was statistically better in the DMC group compared to the THR group (p < 0.001). The DMC showed a statistically better effect on the HRQoL measurements as compared to the THR group. There were no dislocations in both groups. DMC hip replacements provide better functional, patient reported outcomes, and range of motion than the conventional THR. Combined with its stability, DMC replacements are a useful solution in managing femoral neck fractures in active elderly patients.Trial serial number 020841 (IRB Number 00007555).

Inferior stabilization of cementless compared with cemented dual-mobility cups in elderly osteoarthrosis patients: a randomized controlled radiostereometry study on 60 patients with 2 years’ follow-up

Background and purpose — Elderly patients may benefit from a dislocation low-risk dual-mobility (DM) articulation in total hip arthroplasty, but the best cup fixation method is unknown. We compared cup migration for cemented and cementless DM cups using radiostereometry.Patients and methods — In a patient-blinded randomized trial, 60 patients (33 female) with osteoarthritis were allocated to cemented (n = 30) or cementless (n = 30) Avantage DM cup fixation. Criteria were age above 70 years, and T-score above –4. We investigated cup migration, periprosthetic bone mineral density (BMD), and patient-reported outcome measures (PROMs) until 24 months postoperative follow-up.Results — At 24 months mean proximal cup migration was 0.11 mm (95% CI 0.00–0.23) for cemented cups and 0.09 mm (CI –0.09 to 0.28) for cementless cups. However, cementless cups generally migrated more than cemented cups at 12 and 24 months. Cemented cups had no measurable migration from 3 months’ follow-up, while cementless cups had not yet stabilized at 24 months in all rotations. Cementless cups showed statistically significantly more maximum total point motion (MTPM) at 12- and 24-month follow-up compared with cemented cups in patients with low systemic BMD (p = 0.01). Periprosthetic BMD changes did not statisticially significantly correlate to proximal migration in either cup fixation group (p > 0.05). PROMs improved similarly in both groups.Interpretation — Cemented cups were well fixed at 3 months. The cementless cups migrated more in patients with low BMD, showed an inconsistent pattern of migration, and migrated in different directions during the first and second year without tendency to stabilization. Cemented fixation of the Avantage DM cup seems safer in elderly patients

Dual-mobility cups in revision acetabular reconstructions: Short-term outcomes in high-risk patients for instability

ObjectiveThe aim of this study was to evaluate the performance of dual-mobility (DM) cup systems for revision total hip arthroplasty (rTHA) in patients who had high risk for instability. MethodsWe prospectively followed up 34 hips of 30 patients (27 females, 3 males; mean age: 66.1 (range: 33 to 89) years) who underwent rTHA with DM cups for aseptic loosening in 23 hips, infection treatment as second or single stage in nine hips, and instability in two hips. Clinical functions of the patients were evaluated using the Harris Hip Score (HHS), and radiological migration or loosening of the DM cups were recorded. The survival of the components was calculated with the Kaplan-Meier survival analysis and failure was defined as any dislocation of the polyethylene (PE) insert, intraprosthetic dislocation (IPD), aseptic loosening of any component or total hip system revision due to any reason. ResultsThe mean duration of follow-up was 3.52 (range: 2.05 to 6.26) years. There was one dislocation of PE insert (2.9%), which was treated with closed reduction. There were two (5.8%) re-revisions for cemented DM cup due to migration. There was one PE insert and head change due to subacute infection. The mean HHS increased from 42.8 ± 6.7 (range: 34 to 60) points preoperatively to 87.3 ± 5.8 (range: 75 to 98) points postoperatively. The cumulative survival rate of the DM cup system was 91.2% (95% CI: 81.6–100%) with any revision, 94.1% (95% CI: 86.2–100%) with aseptic loosening and %97.1 (%95 CI: 91.4–100%) with dislocation as the end point at 3.5 years. ConclusionDual-mobility cups may provide good stability and represent a good option for revision acetabular reconstruction in patients who have high risk for instability. Level of evidenceLevel IV, therapeutic study.

Cementation of a monoblock dual mobility bearing in a newly implanted porous revision acetabular component in patients undergoing revision total hip arthroplasty.

BackgroundThe most common indications for revision total hip arthroplasty are instability/dislocation and mechanical loosening. Efforts to address this have included the use of dual mobility (DM) articulations. The aim of this study is to report on the use of cemented DM cups in complex acetabular revision total hip arthroplasty cases with a high risk of recurrent instability.MethodsA multicenter, retrospective study was conducted. Patients who received a novel acetabular construct consisting of a monoblock DM cup cemented into a fully porous metal shell were included. Outcome data included 90-day complications and readmissions, revision for any reason, and Harris Hip Scores.ResultsThirty-eight hips in 38 patients were included for this study. At a median follow-up of 215.5 days (range 6-783), the Harris Hip Score improved from a mean of 50 ± 12.2 to 78 ± 11.2 (P < .001). One (2.6%) patient experienced a dislocation on postoperative day 1, and was closed reduced with no further complications. There was 1 (2.6%) reoperation for periprosthetic joint infection treated with a 2-stage exchange.ConclusionsIn this complex series of patients, cementation of a monoblock DM cup into a newly implanted fully porous revision shell reliably provided solid fixation with a low risk of dislocation at short-term follow-up. Although longer term follow-up is needed, utilization of this novel construct should be considered in patients at high risk for instability.

Outcomes for cemented dual mobility cup to treat recurrent instability; A UK case series

ObjectivesRecurrent dislocation of Total Hip Replacement (THR) is often multifactorial and remains a significant surgical challenge with a significant risk of further instability. Dual Mobility Cups (DMC) have been used widely with good long term results in France with few studies in the British literature, especially assessing their use for recurrent instability. We set out to assess whether recurrent instability can be successfully treated solely with revision of acetabular component to a dual mobility cup. MethodsWe retrospectively reviewed a prospectively collected electronic database for all consecutive dual mobility cups implanted to address recurrently instability in THR. Radiological and clinical data have been analysed. ResultsFrom September 2013 to September 2017 54 dual mobility cups have been implanted, mean age 78 (range 49–97). 47 were 1st time revision procedures, 7 were following previous revisions including 5 failed PLADs. Average time post primary was 10 years (range 8 months–23 years). Twenty cases are cement in cement revisions which has become our primary technique for revision of cemented cups. Mean follow up is 1.9 years (range 6 months-5 years), 37 cases have 2 year follow up available. 8 patients have died. There have been no episodes of further instability. One patient has had reoperation for infection (1st stage revision). ConclusionsThis series demonstrates satisfactory early to mid-term results for the use of dual mobility cups to treat recurrent instability. The technique is particularly useful when femoral components are well fixed and can be used with monoblock implants such as the Charnley stem. Cement in cement revision is a convenient technique and potentially reduces complications and cost. Further analysis of longer term data is required but these results suggests this could be a valid solution to a complex problem.

The use of cemented dual mobility acetabular cup in revision hip arthroplasty

Purpose Instability is always an important problem after both primary and revision total hip arthroplasty (rTHA). Dual mobility or tripolar unconstrained acetabular components give a solution for preventing and treating instability. Results of many studies using dual mobility cups (DMC) with mid-term to long-term follow-up support their effectiveness. Complications such as intraprosthetic dislocation (IPD) and accelerated wear have been studied, although they seem to be less significant in older, low-demand patients. However, their use in younger patients should be with caution owing to the lack of current data concerning this high-demand patient population. The aim of this study is to analyze the short-term results of cemented DMCs in rTHA. Specifically, we evaluated the following: clinical outcomes and scoring, dislocation, IPD rates, and other complications. Patients and methods The results of a single design of DMC was prospectively evaluated in a continuous series of 20 rTHAs. Follow-up period was of at least 2 years. Mean age of the patients was 66.8 years old. Results At the 2-year mean follow-up, the dislocation rate was 5%, and the IPD rate was 0%. Improvement of the hip score, function, pain, and range of motion was noticed. Conclusion DMCs demonstrated a low dislocation rate in rTHA but did not solve problems related to perioperative technical errors. Moreover, IPD did not appear to be a concern when compared with the gain of preventing instability.

Revision total hip arthroplasty with a Kerboull plate: comparative outcomes using standard versus dual mobility cups

Instability is a major complication in revision total hip arthroplasty (THA). Dual mobility (DM) cups were shown to reduce the risk of post-operative implant dislocation. Few case-series studies assessed the outcomes of cemented DM cups when associated to acetabular reconstruction antiprotrusio cages. No published comparative studies were found to look for outcome differences between standard cups (SC) and DM cups in first revision THA associated witha Kerboull plate (KP) and acetabular bone grafting. This is a retrospective comparative study of two groups of patients in two institutions. All cases were first revision THA with KP reconstruction; a cemented standard cup (SC) was used in one institution (THA-SC group) while a cemented DM cup was used in the second institution (THA-DM group). The posterolateral approach and the same technique for KP placement, the cross technique, were performed in both groups. Primary outcomes were dislocation and revision rates. Survivorship and clinical and radiological results were set to be secondary outcomes. There were ten patients (13 hips) in the first group and 16 patients (16 hips) in the second with a mean follow-up clinical and radiological evaluation of 74.2 ± 47.9months. Besides age, no significant demographic differences were present between both groups. There were three dislocations (23%) in the first group treated with close reduction compared to none in the second (p = 0.04). No further episode of dislocation or revision surgery occurred until the last follow-up in both groups. The mean Harris Hip Scores for the THA-SC and THA-DM groups were 87.5 ± 10.9 and 87.4 ± 12.1, respectively. When present, radiolucent lines were less than 1mm thick and were non-progressive in both groups. In all patients, complete trabeculation remodeling or cortical repair of the graft was observed. The cup type was the single variable which could account for the observed dislocation rate difference. The mid-term results of using DM cups with KP in first revision THA seem very encouraging. Our findings add to the previously published results on the excellent outcomes in terms of stability in revision THA when using DM cups.