Polyethylene wear of dual mobility cups: a comparative analysis based on patient-specific finite element modeling

Purpose Concerns remain about potential increased wear with dual mobility cups related to the multiple articulations involved in this specific design of implant. This finite element analysis study aimed to compare polyethylene (PE) wear between dual mobility cup and conventional acetabular component, and between the use of conventional ultra-high molecular weight PE (UHMWPE) and highly cross-linked PE (XPLE). Methods Patient-specific finite element modeling was developed for 15 patients undergoing primary total hip arthroplasty (THA). Five acetabular components were 3D modeled and compared in THA constructs replicating existing implants: a dual mobility cup with a 22.2-mm-diameter femoral head against UHMWPE or XLPE (DM22PE or DM22XL), a conventional cup with a 22.2-mm-diameter femoral head against UHMWPE (SD22PE) and a conventional cup with a 32-mm-diameter femoral head against UHMWPE or XLPE (SD32PE or SD32XL). Results DM22PE produced 4.6 times and 5.1 times more volumetric wear than SD32XL and DM22XL (p < 0.0001, Cohen’s d = 6.97 and 7.11; respectively). However, even if significant, the differences in volumetric wear between DM22XL and SD32XL as well as between DM22PE and SD22PE or SD32PE were small according to their effect size (p < 0.0001, Cohen’s |d|= 0.48 to 0.65) and could be therefore considered as clinically negligible. Conclusion When using XLPE instead of UHMWPE, dual mobility cup with a 22.2-mm-diameter femoral head produced a similar amount of volumetric wear than conventional acetabular component with a 32-mm-diameter femoral head against XLPE. Therefore, XLPE is advocated in dual mobility cup to improve its wear performance.

Early Complications of using Dual Mobility Cup in Total Hip Arthroplasty. A Systematic Review

Background Total hip arthroplasty (THA) is considered one of the most successful surgical procedures providing pain relief and improvement of function in patients with end-stage hip arthritis that does not respond to non-operative treatments. As health care continues to improve and life expectancy increases, the demand for total joint replacement will grow to reflect this more active, aging population. Objectives This study aims to review early complications of dual mobility cup arthroplasty. The objective is to perform a systematic review of early complications of dual mobility cup arthroplasty for primary and revision cases. Methodology Types of studies we will include randomized control trails (RCTs), controlled clinical trials, retrospective cohort studies, and we will exclude case reports, case series studies, cross sectional studies, non English studies. Search results will be conducted to systematic review management software and manually screened for eligibility to be included. PRISMA flowchart will be produced based on the search results and the inclusion/exclusion criteria. We will search the MED-LINE database, PubMed, Cochrane Bone and Muscle Trauma Group Specialized Register, Cochrane Register of Controlled Trails (The Cochrane Library) using the following keywords related to: THA, Dual mobility cup, complications, intraprosethetic dislocation. Results Early complication rate in dual mobility cups is significantly higher in revision cases compared to primary cases, with the exception of IPD which was significantly lower in revision cases. Early complication rate of conventional THA was significantly higher than both primary and revision dual mobility cups. Conclusion Dual mobility THAs are a good alternative to traditional bearing surfaces with long survivorship and low rates of instability after primary and revision THA. The rate of complications which are unique to the procedure, including intraprosthetic dislocation, is relatively low and limited mainly to earlier designs. High-quality, prospective, comparative studies are needed to further evaluate the use of dual mobility in primary and revision THA.

The Neck of Femur Fracture in an Elderly Patient with Schizophrenia and Parkinsonism Managed with Dual Mobility Total Hip Replacement – A Rare Case Report

Introduction: Neck of femur fractures is the most common fractures in elderly people as they present with osteoporosis. There is a higher chance of proximal femur fracture in a schizophrenic patient as there is a loss of bone mineral density due to a drug-induced increase in the level of prolactin and immobility. Patients with Parkinson’s disease were at higher risk for the development of hip fractures due to gait disturbances and instability. Case Report: A 63-year-old male patient presented with complaints of the right arm pain, swelling, deformity of the right arm, and difficulty in extending the wrist for 3 days. The patient had a history of falls and trauma to the left arm at home. X-ray right arm showed distal one-third spiral humerus fracture for which intramedullary nailing was done. X-ray of the pelvis with both hips showed right neck of femur fracture with associated greater trochanter (GT) fracture. We managed with total hip replacement using a dual mobility cup and tension band wiring for GT fracture. Postoperatively, the patient has a good range of motion at the hip. The functional outcome is good as per Harris’s hip score. Conclusion: Neck femur fractures in elderly patients with associated comorbidities such as schizophrenia and parkinsonism are best managed with total hip replacement using a dual mobility cup. It avoids the risk of dislocation in high-risk patients and prevents secondary procedures. Careful clinical and radiological examination of the pelvis is very essential even in asymptomatic patients with a history of trauma to prevent delayed diagnosis of these types of fractures in patients with schizophrenia and parkinsonism. Keywords: Neck of femur fracture, Parkinsonism, schizophrenia, dual mobility cup, total hip replacement.

Zurich Cementless Dual Mobility Cup for Canine Total Hip Prosthesis: Implant Characteristics and Surgical Outcome in 105 Cases

Dislocation after total hip arthroplasty (THA) remains a troublesome complication, and a source of frustration for the owner and the surgeon. The dislocation rate of hip prostheses in dogs is reported to range from 4 to 15%, representing the most common short-term complication. This is especially true in large and giant breed dogs, usually requiring revision surgery. With the increase in the number of THA being performed in veterinary surgery, reducing or preventing complications such as postoperative THA dislocation will be of paramount importance. The Zurich cementless dual mobility (DM) system allows impingement-free range of angulation of 80 to 132 degrees between the ceramic head and the polyether ether ketone (PEEK) cup when combined with the range of the PEEK cup in the outer metal cup. In this article, we review the use of the DM cup in THA in large and giant breed dogs, in terms of its history, biomechanics, outcomes and complications based on 105 cases.

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.

Iatrogenic Intraprosthetic Dislocation of Dual Mobility Cup. Case Study

Intra-prosthetic dislocation of the dual-mobile acetabular cup is a rare complication. Most often, it is the result of wear of the polyethylene liner. It can also occur during a closed reduction of a dislocated dual-mobile cup. It is extremely important to recognize this complication immediately in order to avoid the consequences. This paper presents the first case of iatrogenic intraprosthetic dislocation at the Traumatology and Orthopaedics Department of the Military Medical Institute, our management of the case and suggestions for treating patients with a dislocation of the dual-mobile acetabular cup.

Preliminary Results of Total Hip Arthroplasty in Subjects at Risk for Dislocation Using a Novel Modular Cementless Dual-Mobility Cup. A Single-Center Prospective Study

Nowadays total hip arthroplasty (THA) is widely considered the operation of the century in orthopedic and traumatological fields. Despite this fact, instability and dislocation after THA are a common reason for revision surgery. The purpose of this prospective study is to evaluate the preliminary clinical and radiological results of a novel dual mobility cup. We evaluated 32 consecutive cases of patients who underwent THA using a novel dual mobility cup—with holes in the cup, a modular metallic inlay and a crosslinked polyethylene. All of them were considered at risk of instability of the implant due to primary or concomitant diagnosis. The preoperative Harris hip score was 54.7 on average. At a minimum 2 years follow-up, the mean HHS raised up to a mean value of 88.4; this improvement was statistically significant (p < 0.0001). None of the patients enrolled in this study sustained a postoperative dislocation at a mean follow-up of 39.6 months. Furthermore, no patients sustained modular liner dissociation or an intraprosthetic dislocation. As such, survivorship free from dislocation was 100% at both 2 and 5 years. This study demonstrates that the modular dual mobility (DM) socket provides dual articulation, larger jump distance, and greater range of motion before impingement, which significantly reduce the rate of dislocation.