Dual Mobility Cup Research Articles

Wear factor comparison between single and dual mobility cup in total hip arthroplasty

Wear factor comparison between single and dual mobility cup in total hip arthroplasty

Short-term primary and revision modular dual-mobility cup total hip arthroplasty outcomes in high-risk dislocation patients: a retrospective study

PurposeModular dual-mobility cups (MDMCs) have a lower risk for dislocation after total hip arthroplasty (THA). The primary aims of our study were to analyze implant survivorship and to determine complications, especially dislocation, and revision rates of primary THAs used for hip fracture patients and for revision THAs. Secondary aims were to evaluate mortality after MDMC surgery and to find out if introduction of MDMC at our institution (Kuopio University Hospital, Finland) have decreased dislocation rate.MethodsThis retrospective cohort study consisted of 101 MDMC patients who were consecutively operated at our institution between April 1, 2018 and June 30, 2020. The implant survival rate, complications and mortality were evaluated with minimum of 2-year follow-up. Finnish Hospital Discharge Register was used to find out yearly dislocation rates following THA at our institution.ResultsThe cumulative estimate implant survival after MDMC in the primary THA group was 97% at 2 years, and in the revision THA group, it was 90% at 2 years. Dislocation was a rare complication in the primary THA group (1.4%), while it was common in revision THA group (12.9%). The cumulative estimate for mortality after MDMC in the primary THA group was 13% at 2 years, and in the revision group, it was also 13% at 2 years. The yearly number of patients who had re-hospitalization period due to THA dislocation decreased 46% after implementation of MDMC.ConclusionShort-term survival and complication rates after MDMC were excellent after primary THA and moderate after revision THA. Implementation of MDMC THA for hip fracture patients seems to have effectively decrease dislocation rate during a short follow-up.

THE EVALUATION OF TOTAL HIP ARTHROPLASTY IN THE MANAGEMENT OF SPASTIC PAINFUL HIP DISLOCATION IN CEREBRAL PALSY

Spasticity used to be considered a contraindication for total hip replacement (THR) procedures. Due to the development of implants as well as surgical skills, THR became an option for the treatment of painful dislocation of the hip joint in patients with spastic plegia. The aim of this study was an evaluation of mid-term results of THR in spastic CP adolescent patients with painful hips with hip joint subluxation or dislocation.In 2014–2022, 18 pts (19 hips) with CP aged 16 to 20 years underwent THR in our department. The mean follow-up was 4 years (range: 1 – 9 years). Results were evaluated using the Gross Motor Function Scale, VAS scale in accordance with the Ashworth scale, types of implants used (dual mobility cup and not dual mobility cup), and radiological assessment (Crowe scale). Complications have been thoroughly analyzed.In 10 pts there has been an improvement in the GMFSC scale average from 1 to 2 points observed after the surgery. All pts have improved in the VAS scale average of 8 points (from 10 to 7). According to the Crowe scale repositioning of preoperative dislocation to primary acetabulum was achieved in all cases. Complications occurred in 4 cases: dislocations of 2 THR with dual mobility cup and 2 THR with non-dual mobility cup requiring revision surgery with good final result. No statistical significance was noted according to the type of cup (Mann-Whitney U Test).The most important risk factor for complications is severe spasticity. We believe, that CP pts with painful hips should be treated using THR. We didn't observe any significant differences between the types of implants.These findings may serve as a basis for the prediction of outcomes of THR treatment in this specific group of pts.Level of evidence: Case-control or retrospective comparative study-Level III

THE COMBINED USE OF SINGLE- AND DUAL-MOBILITY CUPS IN PRIMARY TOTAL HIP ARTHROPLASTY IS SAFE IN A UNIVERSITY HOSPITAL PRACTICE

Dislocation after Total Hip Arthroplasty (THA) is a frequent cause of revision and patients with intrinsic risk factors have been identified. The use of dual mobility (DM) cup has shown great efficiency in preventing dislocation, with questions regarding selective or absolute use. The aim of this study was to compare the outcome of single mobility THA (SM-THA) and DM-THA, when used for selected patients.This retrospective continuous cohort study evaluated 490 patients of whom 275 received SM-THA and 215 received DM-THA. There were 304 primary osteoarthritis (62%), 121 femoral neck fractures (24%) and 65 other indications (14%). The surgical approach was anterior (AA) in 79% and posterior (PA) in 21% of cases. In the DM-THA group, 189 patients (87%) presented at least one dislocation risk factor compared to 128 patients (46%) in the SM-THA group. The primary outcome was revision for all causes, with or without implant removal. Secondary outcomes included length of hospital stay.There was no difference in all cause revision at two years follow up with 9 procedures (3.2%) in SM-THA group and 11 in DM-THA group (5.1%) (p=0.3). There were 3 dislocations in SM-THA group (3 AA) and 3 in DM-THA group (2 PA and 1 AA) (p=0.4).The length of stay was significantly longer in DM-THA group with 7 days (2–12) compared to 4 days (1–7) in SM-THA group (p=0.001).SM-THA and DM-THA are two complementary devices in the management of patients requiring primary THA. SM-THA is a safe option for patients without dislocation risk factors, especially when using AA. The identification of such factors is important to select patients requiring DM-THA and provide reproducible outcomes in a University Hospital practice including various levels of surgeon experience.

Validation of mediCAD® software for fully digital preoperative planning of total hip arthroplasty: a retrospective study

IntroductionThe planning step that precedes a total hip arthroplasty (THA) procedure is crucial. Digital planning software programs are being increasingly used, although few studies have reported on the reliability of such tools. Furthermore, no studies have been conducted on the mediCAD® software, despite it being widely used in France. This led us to conduct a retrospective study to: (1) assess the accuracy of this planning software, (2) determine the intra- and inter-rater reliability, (3) determine how obesity affects the accuracy of planning. HypothesisTHA planning is accurate and reliable when using the mediCAD® software. Patients and methodsThis was a single center, retrospective study. One hundred one consecutive cases performed by a single experienced surgeon were planned retrospectively by two blinded surgeons on two separate occasions. The acetabular cup was cemented in 90 hips (89%), cementless in 11 hips (11%). A dual mobility cup was used in 21 hips (21%). The femoral stem was cemented in 60 hips (59%). The endpoint was the number of exact plans, defined as the same size as the actual implants. An acceptable match was defined as a difference of one size. The match was unacceptable if the planned and implanted size differed by more than 2 for the acetabular cup or by more than 1 size for the femoral stem. The intra-rater and inter-rater reliability were calculated using the intraclass correlation coefficient (ICC) with 95% confidence intervals (CI). ResultsExact agreement was found by the first rater for 15 planned acetabular cups (15%) and for 45 planned femoral stems (45%) relative to the implants used. The second rater reached exact agreement for 20 planned acetabular cups (20%) and 50 planned femoral stems (50%). The intra-rater reliability for the acetabular cup was average (ICC = 0.57; 95%CI [0.43–0.69]) and poor (ICC = 0.38 95%CI [0.20–054]) for the 1st and 2nd rater, respectively. The intra-rater reliability for the femoral stem was poor for the 1st rater (ICC = 0.47 95%CI [0.30–0.61]) and the 2nd rater (ICC = 0.45 95%CI [0.29–0.60]). The interobserver reliability was low for the planned acetabular cup (ICC = 0.39 95%CI [0.21–0.54]) and the planned femoral stem (ICC = 0.42 95%CI [0.24–0.57]). Overall, when combining the two raters, exact prediction of the acetabular cup was achieved in 31 hips (19%) in non-obese patients and in 7 hips (21%) in obese patients (p = 0.62). DiscussionThis study found acceptable reliability of the mediCAD® software. Experience level, radiograph magnification affected the planning outcome in this study, but obesity did not. We currently do not have the ability to incorporate a reliable radiological scale for two-dimensional templating. Some surgeons prefer using a CT scan, but this costs more than conventional radiographs and exposes the patient to more radiation. This study shows that the mediCAD® software can provide satisfactory output for the preoperative planning of THA. Level of evidenceIII; retrospective, diagnostic, comparative study

Results of third generation dual mobility total hip arthroplasties with non-cross-linked polyethylene in patients under 60 years of age: comparative study of full pressfit vs. tripod cups after 8.6 years

BackgroundThe concept of dual mobility of total hip arthroplasties (THA) is a revolution in the prevention of dislocations and in the treatment of instability. Its use remains controversial in patients under 60 years old, providing poorer results with first generation cups coated with alumina. This study, carried out on modern dual mobility (DM) cups with a porous bilayer coating, in active patients under 60 years of age aimed to evaluate: (1) the mechanical survival of two latest generation DM THA, with failure defined as revision of acetabular or femoral implants for mechanical loosening, by comparing a tripod cup to a full pressfit cup, (2) to evaluate the complications, (3) to compare the rate of radiographic peri-prosthetic osteolysis between the 2 implants. HypothesisThe hypothesis was that the medium-term survival of modern DM cups placed in young patients was the same regardless of the type of acetabular fixation used. Materials and methodsThis was a retrospective study of 119 latest generation DM THA with standard polyethylene, composed of 66 full pressfit cups and 53 tripod fixation cups, used in primary arthroplasty in 111 patients between 2005 and 2016. The survival study was carried out using medical records. The clinical evaluation was carried out using the modified Harris Hip Score (mHHS) as well as the self-administered Hip and Osteoarthritis Outcome Score (HOOS) and Oxford-12 questionnaires. Radiological analysis was carried out on radiographs looking for bone demineralization and acetabular and femoral lines. ResultsAt 8.6 years (5–16), no revision for mechanical loosening was observed regardless of the type of cup. The prosthesis dislocation rate (large joint) was 1.7%: 1 case in each group (p = 1), including one revision required in the full pressfit group. Three revisions for mechanical complications were recorded: a recurrent dislocating hip on a full pressfit cup that was not sufficiently anteverted, an acetabular peri-prosthetic fracture on a full pressfit cup and a case of iliopsoas impingement with a retroverted tripod cup. The survival rate for all-cause revision was 93.8% for pressfit (95% CI: 88.2%–99.9%) vs. 96.2% for tripod (95% CI: 91.1%–100%) (p = 0.63) and for revision due to any cause excluding infection, 96.9% for pressfit (95% CI: 92.8%–100%) vs. 98.1% for tripod (95% CI: 94.4%–100%) (p = 0.7). The rate of periacetabular osteolysis was 11%, significantly more present amongst tripod cups (24%, 9 cases) compared to full pressfit cups (2%, 1 case) (p < 0.01). ConclusionThis series demonstrates good performance of 3rd generation DM cups with porous bilayer coating in patients under 60 years of age regardless of the type of acetabular fixation, at 8.6 years of follow-up. The rate of osteolysis around full pressfit cups remains very low, unlike that of tripod cups. The use of Double Mobility prostheses for primary hip osteoarthritis is possible in young patients, preferably with full pressfit cups (i.e., without any pegs or additional screws that may promote diffusion of polyethylene debris and osteolysis). Level of evidenceIII; comparative retrospective study.

Dual Mobility Cup in Total Hip Arthroplasty

Abstract Background Proximal femoral fractures are considered a common problem in the elderly. Osteoporosis and the risk of fall especially in old age add to the complexity of management of these types of fractures. These fractures can be managed with different types of implants e.g. Dynamic hip screw, proximal femoral nail, proximal femoral plate, etc.. Aim of the Work Prospective clinical trial study to assess the role of dual mobility unconstrained acetabular components in preventing and treating instability. Patients and Methods In the period between December 2014 to April 2017 a prospective study was conducted involving 25 patients with high risk of dislocation underwent total hip replacement using dual mobility cup either as primary hip arthroplasty or revision hip arthroplasty. All cases were operated upon in Ain Shams University Hospitals and the follow up of the cases was 1 year. Results There were no cases of prosthesis dislocation or loosening. There were only two cases of superficial wound infections who improved with wound debridement. Studies showed that the dual mobility cup did a great success in reduction in the risk of dislocation in specific conditions as patients with polio and other neuromuscular disorders and other risk factors for head dislocation. Conclusion Conversion of a failed implant to a total hip implant is a good and safe option in treatment of such cases. Dual mobility cups decreased the risk of dislocation in such cases with increased longevity of the prosthesis and a considerably accepted range of motion of the hip joint.

Liner orientation change of dual mobility cup determined via 3D ultrasound imaging and motion analysis: A cadaver study

BackgroundA mobile polyethylene liner enables the dual mobility cup (DMC) to contribute to restoring hip joint range-of-motion, decreasing wear and increasing implant stability. However, more data is required on how liner orientation changes with hip joint movement. As a first step towards better understanding liner orientation change in vivo, this cadaver study focuses on quantifying DMC liner orientation change after different hip passive movements, using ultrasound imaging and motion analysis. HypothesisThe liner does not always go back to its initial orientation and its final orientation depends mainly on hip movement amplitude. Methods3D ultrasound imaging and motion analysis were used to define liner and hip movements for four fresh post-mortem human subjects with six implanted DMC. Abduction and anteversion angles of the liner plane relative to the pelvis were measured before and after hip flexion, internal rotation, external rotation, abduction, adduction. ResultsLiner orientation changes were generally defined by angle variation smaller than 5°, with the liner nearly going back to its initial orientation. However, hip flexion caused liner abduction and anteversion angle variations greater than 15°. Except for hip adduction, only weak or no correlation was found between the final angle of the liner and the maximal hip joint movement amplitude. DiscussionThis study is the first attempt to quantify liner orientation change for implanted DMC via ultrasound imaging and constitutes a step forward in the understanding of liner orientation change and its relationship with hip joint movement. The hypothesis that the final liner abduction and anteversion angles depend mainly on hip movement amplitude was not confirmed, even if hip flexion was the movement generating the most liner orientation changes over 15°. This approach should be extended to in vivo clinical investigations, as measured liner angle variation could provide important support for the wear and stability claims made for DMC. Level of evidenceIV; cadaveric study.

The Use of Dual-Mobility Implants Through a Direct Anterior Approach as a Safe and Effective Technique for Revision Hip Arthroplasty: The Two-Year Follow-Up of a Case Series.

Background Dislocation is one of the most prominent and challenging complications following the revision of total hip arthroplasty (THA). Dual-mobility cups are an option to address this problem. There is, however, little data on the outcomes of modern modular dual-mobility (MDM) cups in the revision of THA. In this study, the clinical and radiological outcomes following the revision of THA with an MDM cup using the direct anterior approach (DAA) were evaluated. Methodology We retrospectively reviewed patients who underwent a revision of THA between March 2017 and July 2019. The inclusion criteria were a revision of THA using an MDM cup through the DAA. A uniform acetabular implant was used in each revision. Outcome measures were assessed radiographically and clinically. The clinical outcome measures consisted of dislocation, infection, and re-revision. Functional assessment was performed using the Harris Hip Score preoperatively and at the last clinical examination in our department. Results This study retrospectively identified a cohort of 26 patients who underwent a revision of THA. Two patients were excluded due to incomplete follow-up because they died. Finally, 24 patients were included. A total of 17 isolated acetabular revisions and seven complete revisions were performed with a mean follow-up of 39 months (range = 29-59). No dislocations or deep infections were observed in our population to date. Except for one case of early aseptic loosening of the acetabular component, we observed no other signs of loosening, osteolysis, migration, or intraprosthetic dislocation. Conclusions THA revision through the DAA using an MDM cup is a safe and effective procedure. We observed no dislocation in a high-risk population undergoing THA revision surgery during a minimal follow-up of two years.

Anterior-approach total hip arthroplasty in patients with poliomyelitis: Long-term outcomes

ObjectiveIn patients with residual poliomyelitis-related impairments, total hip arthroplasty (THA) is challenging due to the high frequency of risk factors such as hip dysplasia, dislocation, muscle weakness, and fracture. The objective of this study was to assess the long-term functional and radiographic outcomes of anterior-approach THA with a ceramic-ceramic, dual-mobility, or constrained implant in patients with poliomyelitis sequelae. HypothesisTHA via the anterior approach with a ceramic-ceramic, dual-mobility, or constrained implant is a reliable technique that is not associated with excess risks of instability or aseptic loosening. Material and methodsThis single-centre retrospective study included consecutive patients with poliomyelitis sequelae who underwent THA between January 1998 and September 2019 via the anterior approach, with implantation of a ceramic-ceramic, dual-mobility, or constrained implant. The Harris Hip Score (HHS), implant position, and complications (e.g., infection and loosening) were collected during the most recent in-person visit. ResultsThe study included 19 patients (23 hips). Mean follow-up was 5.2 ± 4.2 years (range, 2.0–10.6 years). Only six of the 23 procedures were done on the side with greater muscle weakness. The mean HHS at last follow-up was 80.4 ± 10.4. A single procedure (1/23, 4%) was followed by a complication, consisting in intra-prosthetic dislocation 2 years after implantation of a dual-mobility cup. At last follow-up, the HHS was not associated with psoas and gluteus muscle strength (rs = 0.35, p = 0.11 and rs = 0.37, p = 0.09, respectively) and was not significantly different between the weaker vs. stronger side (82.7 ± 8.0 vs. 79.5 ± 11.3, respectively; p = 0.53). Cup position was more horizontal, thereby optimising function, when the procedure was done on the weaker vs. the stronger side (39.9° ± 4.3 vs. 45.0° ± 6.8, respectively; p = 0.02). ConclusionTHA is a good option for improving function in patients with poliomyelitis sequelae. THA via the anterior approach with a ceramic-ceramic, dual-mobility, or constrained implant is a reliable method that is not associated with an excess risk of instability or loosening. Level of evidenceIV.

The Avantage ® dual mobility cup in primary total hip arthroplasty: A registry study

BackgroundAvantage Cup has been widely used in dual mobility implants. However, in Swedish Registry, the outcome of the Avantage Cup is reported with higher implants revision compared to control. The aim of our study was to verify if the same results are present in the Registry of Prosthetic Orthopedic Implants (RIPO) of Emilia Romagna (ER, Italy), as the Avantage cup was the most implanted dual mobility cup for a long follow-up reported in this Registry (2000–2012). Furthermore, we assessed the survival rate of the implant over the time. MethodsWe included all patients that underwent a primary THA using the Avantage cup during the period 2000–2020 in RIPO Registry. The survivorship of the primary THA implants was calculated and plotted according to Kaplan-Meier method. Results886 Avantage cups were included in the analysis. During the observational period 44 hips were revised. The most common reasons for revision were: periprosthetic fractures (PPF) (n = 7, 0.8 %), deep infection (n = 7, 0.8 %), and cup aseptic loosening (n = 13, 1.5 %).The survival rate of the implant was 96.8 % (95.3–97.8) at 5 years, 95.7 at 10 years (94.0–97.0) and 92.1 at 15 years (88.5–94.6). ConclusionIn conclusion, this study has demonstrated that the Avantage cup in primary hip arthroplasty implanted with a “friendly” femoral stem granted satisfactory long-term survival. Therefore, in the Swedish Registry, the cause of the poor results presented for Avantage Cup could be the thick, rough neck stem of the widely used Lubinus stem.

Dual Mobility Cup Fixation Augmented by Pegs and Screws for Total Hip Arthroplasty in a Geriatric Population with Osteoporosis: Short- and Medium-Term Results of a Retrospective Series of 45 Patients

Introduction: Total Hip Arthroplasty (THA) requires stable primary fixation of the acetabular implant. The main objective of this study was to evaluate, in a geriatric population, the radiological results and the medium-term survival of a Dual Mobility Cup (DMC) with hydroxyapatite coating and tripod fixation augmented by 2 pegs and a screw. Hypothesis: In a geriatric population prone to osteoporosis, this type of implant offers medium-term survival &gt;95% and a complication rate similar to the data from the literature. Methods: This single-center retrospective study included 45 patients (30 women and 15 men) with a mean age of 79.3±5.4 years. Patients included were over 70 years old, with this type of implant for any indication for a first-line THA (30 cases) or revision (15 cases), the initial indication was a proximal femoral fracture in 71% of cases. For each patient, X-rays, clinical scores (Oxford Hip Score, EQ-5D-5L, Parker score) and implant survival were evaluated at the last follow-up. Results: The mean radiological follow-up was 25.4±16 months. Clinical follow-up was 39.9±14 months for 30 patients. For 15 patients (4 lost to follow-up and 11 deceased), clinical data were not available. For 3 patients, periprosthetic osteolysis was observed in zones I and II, as per the DeLee and Charnley system. The Oxford Hip Score was 41.1±8.8 (range: 16-48). The mean VAS was 0.9±1.6 and the mean EQ-5D-5L was 0.6±0.3. Discussion: The use of DMC with fixation augmented by pegs and screws is safe and effective in the short and medium term for THA in a geriatric population.

ENDOPROSTHETIC REPLACEMENT FOR NON-ONCOLOGICAL CONDITIONS (EPRO) STUDY: A UK MULTICENTRE STUDY INTO CLINICAL OUTCOMES OF PROXIMAL FEMORAL REPLACEMENT

This large UK multicentre study evaluates clinical outcomes and identifies factors associated with local complication following PFR for non-oncological conditions.132 patients across four UK centres underwent PFR from 01/08/2004-28/03/2023 with median follow-up of 1.9 (Q10.5-Q34.2) years. 75 (56.8%) patients were female and the mean age was 74.0 (SD 11.7) years. 103 (78%) patients had Charleston Comorbidity Index ≥3. ASA class was III or IV in 66.6%. Indications were infected revision (39, 29.5%), periprosthetic fracture (36, 27.3%), acute trauma (30, 22.7%), aseptic revision (17, 12.9%), failed trauma (nine, 6.8%) and complex primary arthroplasty (one, 0.8%). The primary outcome was the local complication rate. Secondary outcomes were systemic complications, reoperation and mortality rates. Comparisons were made with t-tests and Chi2 tests to investigate patient and surgical factors associated with local complication. Statistical significance was p&lt;0.05.There were 37(28.0%) local complications. These were 18 (13.6%) dislocations, eight (6.1%) prosthetic joint infections, four (3.0%) haematomas, three (2.3%) superficial infections, one (0.8%) wound dehiscence, one (0.8%) sciatic nerve palsy and one (0.8%) femoral perforation. Dislocation mostly occurred in conventional articulations (12, 9.1%) followed by dual-mobility cups (three, 2.3%), constrained cups (two, 1.5%) and hemiarthroplasty (one, 0.8%). Median time to local complication was 30 (Q14-Q3 133) days. Seven (5.3%) patients developed a systemic complication. Thirty-three (25.0%) patients underwent reoperation. Thirty-day and one-year mortality rates were 3.8% and 12.1%, respectively. Longer surgical waiting times (7.9 \[SD 16.9) versus 2.6 \[SD 4.4\] days, p&lt;0.001) and longer operating times (212.5 \[SD 71.8\] versus 189.4 \[SD 59.3\] mins, p=0.0450) were associated with local complication.Due to its high complication rate, PFR should be a salvage option when performed for non-oncological indications. Conventional articulations should be avoided. PFR should be delivered in a timely manner and ideally as dual-consultant cases to reduce operating time.

Decreased Instability in High-Risk (Hip–Spine 2B) Patients After Modifications of Surgical Planning and Technique

BackgroundPatients undergoing primary total hip arthroplasty (THA) who have spinal deformity and a stiff spine are the highest-risk group for instability. Despite the increasing use of dual-mobility cups and large femoral heads, dislocation remains a major complication after THA. Preoperative planning becomes a critical aspect of ensuring precise component positioning within a safe zone. The purpose of this study was to investigate dislocation rates over a 9-year period. MethodsA retrospective review of 4,731 THAs performed by 3 orthopaedic surgeons between January 2014 and March 2023 was performed. Spinopelvic measurements were conducted to determine the hip–spine classification group for each patient. Only patients classified as 2B (pelvic incidence-lumbar lordosis > 10° and Δsacral slope < 10°) were eligible. Both absolute and relative dislocation frequencies were then analyzed using time-series analysis techniques and Fisher’s exact tests. ResultsA total of 281 hip–spine 2B patients undergoing primary THA were eligible for analysis (57% women; mean age, range: 66 years, 23 to 87; mean body mass index, range: 28, 16 to 45). The overall dislocation rate was 4.3%. Use of femoral head sizes ≥ 40 mm increased from 4% in 2014 to 2019 to 37% in 2020 to 2023 (P < .001), while the use of dual-mobility cups decreased from 100% in 2014 to 2019 to 37% in 2020 to 2023 (P < .001). Acetabular component planning was changed from the supine plane to the standing plane in February 2020. Those changes in surgical practice were notably correlated with a significant decrease in dislocation rates from 6.8% in 2014 to 2019 to 1.5% in 2020 to 2023 (P = .03). ConclusionsOur study demonstrates that the introduction of advanced preoperative THA planning to the standing plane, coupled with precise intraoperative technology for implant placement, can significantly reduce the risk of instability in high-risk THA patients. Notably, we observed a significant decrease in dislocation rates, which aligned with the shift in surgical practice. Level of EvidenceIV.

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.

FUNCTIONAL OUTCOME OF TOTAL HIP ARTHROPLASTY WITH DUAL MOBILITY CUPS IN HIP ARTHRITIS-A PROSPECTIVE COHORT STUDY

Background: Dual mobility (DM) total hip arthroplasty (THA) has gained popularity due to its potential to enhance stability and reduce dislocation rates compared to traditional THA constructs. However, there is a need for further investigation into its functional outcomes, complications, and implant survivorship. Method: We conducted a hospital-based prospective study involving 50 patients undergoing total hip replacement over a one-year period. Functional outcomes were assessed using the Harris Hip Score (HHS) and Posterior Muscle Endurance (PME) Score. Descriptive statistics were used for data analysis. Results: The study population consisted predominantly of older patients (mean age 64.30 years), with a higher representation of males (56%). The most common diagnosis was neck of femur fracture (NOF#) (75%), with a balanced distribution of cemented (40%), uncemented (40%), and hybrid (20%) fixation techniques. HHS and PME scores showed significant improvements over 12 months, with excellent outcomes observed in 61.1% of participants. Complications occurred in 14% of patients, with peri-prosthetic fracture and surgical site infection being the most common. Implant survivorship at final follow-up was 94%. Conclusion: Dual mobility cup total hip replacement demonstrates promising outcomes in terms of functional improvement, low complication rates, and high implant survivorship. It represents a viable option for patients undergoing THA, particularly those at risk of dislocation. Further research, including prospective comparative studies, is needed to better understand its long-term efficacy and suitability across different patient populations.

Assessment of polyethylene wear in dual mobility implant for Asians on various head-to-liner ratios: A finite-element analysis

Based on several references, Asians carry out several daily activities that are different from Westerners, which require a greater range of motion. Because of that, a dual mobility (DM) implant was created that was adapted to the activities of Asian people. One of the factors that might shorten the life of a hip implant is wear. Simulations of wear that are based on computation can guide product design to reduce the amount of adhesive and abrasive wear. Even though advanced modeling approaches have been established, a great deal of wear is still not understood, especially regarding the metal-on-polyethylene articulations found on DM cups. It is critical to examine the wear on the DM cup's head-to-liner ratio to determine the proper head diameter and liner thickness for this DM cup. In this work, wear was analyzed using finite-element analysis and compared between three different femoral head diameters matched with different thicknesses of the polyethylene liner on DM cups. Wear was analyzed throughout the regular walking cycle at each head-to-liner ratio. The findings of this study can be used to develop a dual-mobility artificial hip joint for Asians with the slightest wear.

Dual-Mobility Cups in Patients Undergoing Primary Total Hip Arthroplasty with Prior Lumbar Spine Fusion: A Systematic Review

Spine and hip abnormalities frequently occur together in most of the orthopedic population; therefore, both of these abnormalities impact the outcomes of the modalities that are being used. Few studies have reported reduced dislocation and revision rates with the use of dual-mobility cups (DMCs) in high-risk lumbar spine fusion (LSF) patients undergoing primary total hip arthroplasty (THA). This study aims to clarify the relationship between pre-existing lumbar spinal fusion and the outcomes of THA with dual-mobility constructs. We systematically reviewed the current literature through several online databases following PRISMA protocol and the Cochrane Handbook for Systematic Reviews of Interventions. We used the methodological index for non-randomized studies (MINORS) to evaluate the methodological quality of the included trials. Four studies examined the feasibility and effectiveness of dual-mobility cups in patients undergoing primary THA with prior LSF. Two studies were conducted in the United States, while the other two originated in Finland and France, respectively. The included studies enrolled 284 patients. Most of these patients had instrumented fusions. Seventy-eight percent of patients received one- or two-level fusions. The average age across the studies was 68.22 and the mean body mass index was 28. No cases of postoperative DMC implant dislocations were identified. The incidence of postoperative complications was 6% (10/173), including deep venous thrombosis, periprosthetic loosening, infection, and fracture, greater trochanteric fracture, and superficial wound infections. Most included studies had some methodological limitations, with an average MINORS score of 10.5 ± 5.8. The use of dual-mobility cups in these high-risk patients undergoing total hip arthroplasty may lead to reduced dislocation rates and postoperative complications. Further long-term follow-up studies are warranted to support these findings.

Acorn Traser dual mobility cup: Osseo Integration signs

The use of 3D-printed highly porous titanium acetabular cups is becoming popular in Total Hip Arthroplasty (THA) [1,2]. Their porosity mimics that of natural cancellous bone, leading to hopes for more rapid and effective osseo integration compared to traditional titanium and HA-coated implants [1,2]. The Acorn Traser cup (Permedica Orthopaedics S.p.A., Merate, Italy) is a new cement less monobloc Dual Mobility Cup (DMC) recently introduced to the market [3,4]. The cup features a highly porous trabecular structure (Traser) on the bone-cup surface and a titanium-niobium nitride (TiNbN) ceramic coating on the articular side to improve tribological behavior of the titanium shell against the mobile liner.

DUAL-MOBILITY ARTICULATION CONFERS LOWER DISLOCATION AND REVISION RATES: A STUDY USING REVIEW OF REVIEWS METHODOLOGY

Dislocation post THA confers a higher risk of re-dislocation (Kotwal et al, 2009). The dual mobility (DM) cup design (1974) was aimed at improving the stability by increasing the femoral head to neck ratio (Cuthbert et al., 2019) combining the ideas of low friction arthroplasty with increased jump distance associated with a big head arthroplasty.Understand the dislocation rates, rates of aseptic loosening, infection rate and revision rates between the 2 types of constructs to provide current and up-to date evidence.Medline, pubmed, embase and Cochrane databases were used based on PRISMA guidelines. RevMan software was used for the meta-analysis. Studies (English literature) which used DM construct with atleast 6 months follow-up used as intervention and non DM construct as control were included. 2 independent reviewers conducted the review with a third reviewer in case of difference in opinion regarding eligibility. Primary outcome was dislocation rate and secondary outcome was rate of revision.564 articles identified out of which 44 articles were screened for full texts and eventually 4 systematic review articles found eligible for the study. Thus, study became a review of systematic reviews. From the 4 systematic reviews, another 35 studies were identified for data extraction and 13 papers were used for meta-analysis. Systematic reviews evaluated, projected an average follow up of 6-8 years with significantly lower dislocation rates for DM cups. The total number of patients undergoing DM cup primary THA were 30,559 with an average age 71 years while the control group consisted of 218,834 patients with an average age of 69 years. DM group had lower rate of dislocation (p &lt; 0.00001), total lower rate of cup revision (p &lt; 0.00001, higher incidence of fracture (p&gt;0.05).DM THA is a viable alternative for conventional THA. The long-term results of DM cups in primary THA need to be further evaluated using high quality prospective studies and RCTs.