Prevention of dislocation of total hip arthroplasty: the dual mobility cup

The concept of dual mobility cup has been developed to associate the advantages of the low friction total hip arthroplasty with those of large femoral head diameter, with the goal of preventing the dislocations. In this study, 100 primary THA and 34 revision THA with the use of dual mobility cup were analyzed clinically and radiological over a period of fellow up of ten years. It appears that the dual mobility cup is effective against dislocation. Any concerns regarding the survival of this type of prosthesis can be relativized. Literature datas indicate that mean total volumetric wear is of the same order as that reported for Charnley prosthesis with a head of 22,2 mm. However, uncertainty regarding the problem of intraprosthetic dislocation did persist.     

Primary total hip arthroplasty with dual mobility socket to prevent dislocation: a 22-year follow-up of 240 hips

Purpose  

The longest follow-up dual mobility series from inventor Gilles Bousquet focussing on implant survival and the incidence of dislocation.     

Acetabular revision in total hip replacement with a press-fit cup

The need for supplementary screw fixation in acetabular revisions is still widely debated. We carried out 439 acetabular revisions over an eight-year period. In 171 hips with contained or small segmental defects, the Morscher press-fit cup was used. These revisions were followed prospectively. No screws were used for additional fixation. A total of 123 hips with a mean follow-up of 7.4 years (5 to 10.5) were available for clinical and radiological review. There was no further revision of a press-fit cup for aseptic loosening. Radiological assessment revealed osteolysis in three hips. Of the original 171 hips there was cranial and medial migration of up to 6 mm at two years in 44 (26%). No further migration was seen after the second post-operative year. Acetabular revision without screws is possible with excellent medium-term results in well selected patients.     

Simultaneous bilateral dual mobility total hip arthroplasty dislocation in a patient with hepatic encephalopathy: A case report

Introduction and importanceDislocation is a severe complication after total hip arthroplasty (THA). It is one of the most common reasons for failure and revision surgery. This is the first case of a documented simultaneous bilateral dual mobility (DM) THA dislocation.Case presentationA forty-nine-year-old man presented with bilateral hip pain, immobility and deformity. X-ray images demonstrated simultaneous bilateral posterior THA dislocation. Previously, the patient had presented atraumatic dislocations recurrently. When he was thoroughly re-interrogated, he complained of uncontrolled and generalized muscle contractions, which were compatible with myoclonus due to hepatic encephalopathy (HE). Multidisciplinary treatment was performed satisfactorily to control myoclonus symptomatology and to prevent dislocation.Clinical discussionPatient’s most important risk factor was a neuromuscular disorder, which we initially gave little notice and undervalued. HE is a serious but reversible syndrome, observed in patients with liver dysfunction. It leads to a wide spectrum of neuropsychiatric abnormalities. Management is based on prevention of episodes, avoiding the underlying triggers.Due to the high risk for dislocation of our patient, we decided to use DM cups bilaterally. This system has demonstrated lower rates of dislocation.ConclusionThis case report reminds us that a careful evaluation through meticulous history and physical examination are mandatory when faced with recurrent instability. Furthermore, prevention of dislocation is vastly preferable to treating this challenging complication. High-risk patients should be identified, and appropriate surgical approach, technique and implants have to be collectively used to reach a strategy that mitigates and ideally prevents dislocation.     

髋臼假体角度与全髋关节置换术后脱位的关系

目的研究人工全髋关节置换术（THA）髋臼假体安装固定角度与术后髋关节脱位的关系。方法在X线片测量236例（248髋）THA术后的髋臼外展角和前倾角,将外展角设定为〈30°、30-50°、〉50°3组,前倾角设定为〈0°、0-25°、〉25°3组。分析以上2个因素与术后髋关节脱位的关系。结果脱位组外展角平均（39±11．88）°,非脱位组为（38．98±8．65）°,两组之间外展角差异无统计学意义（P=0．449）;脱位组前倾角平均（12．33±14．89）°,非脱位组为（13．21±11．52）°,两组之间前倾角差异无统计学意义（P=0．131）°外展角在〈30°、30-50°、〉50°不同范围的脱位率差异无统计学意义（P〉0．05）,前倾角在〈0°、0～25°、〉25°不同范围内的脱位率差异无统计学意义（P〉0．05）。结论髋臼假体外展角在14～58°范围内、前倾角在-15～350范围内与THA术后脱位之间不存在相关性。     

Severe metallosis owing to intraprosthetic dislocation in a failed dual-mobility cup primary total hip arthroplasty

We report a case of extensive metallosis owing to an intraprosthetic dislocation of a dual-mobility cup after a primary total hip arthroplasty. A 70-year-old man was referred to us from another center with a painful right hip 3 years after the arthroplasty. Initial investigations were suspicious of osteolysis secondary to metallosis with the characteristic "bubble sign" visualized on plain radiographs. At the revision procedure, widespread black staining of soft tissues and bone was noted. The polyethylene liner had dislodged leading to erosion of the metal socket by the prosthetic head. Histopathology examination of periprosthetic tissue confirmed metallosis. To our knowledge, this is the first reported case of severe metallosis owing to a known complication of dual-mobility sockets.     

Cementless total hip arthroplasty with a threaded acetabular cup

Summary. Eighty cementless total hip arthroplasties, using smooth threaded cups (Lord universal model), were carried out between 1985 and 1988. Sixty of these patients were available for clinical and radiological study with a mean follow up of 6 years. Five cups were revised for aseptic loosening and another 6 are awaiting revision, so 18% of the cups have failed. Fixation was classified as stable, fibrous-stable and unstable on radiographs. Twenty-six (43%) had fibrous-stable fixation and most were satisfactory clinically. This type of fixation must be carefully watched for signs of osteolysis, especially around the threads, as this precedes failure. Smooth threaded cups have good short term results, but deteriorate because of deficient osteointegration and later from wear debris. This type of cup does is not a good alternative to cemented cups.

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Résumé. Etude rétrospective de 80 arthroplasties totales par prothèse non cimentée utilisant une cupule vissée lisse (de type LORD) faite entre 1985 et 1988. 60 cupules vissées ont pu faire l’objet d’une étude clinique et radiologique avec une durée d’observation moyenne de 6 ans (4 à 10). 5 cupules ont été reprises pour un descellement aseptique et 6 autres doivent être révisées prochainement. Si l’on considère ces deux groupes, il y a donc 18% d’échec pour ces cupules. Une classification radiologique de la fixation de la cupule a été retenue en 3 types: fixation stable, fixation fibreuse stable et fixation instable. Seulement 23 hanches (38%) montraient radiologiquement une fixation stable de la cupule. 26 (43%) avaient une fixation fibreuse stable correspondant à un bon résultat clinique dans la majorité des cas. Ce type de fixation doit être observé attentivement en recherchant des signes discrets d’ostéolyse notamment le long du filtage, car c’est habituellement un stade précédant l’échec de fixation. D’après notre étude, nous pensons que les cupules lisses vissées permettent un bon résultat clinique et radiologique à court terme mais que la qualité de la fixation se détériore rapidement, probablement à la suite de défaut d’intégration puis comme résultat de la réaction aux débris d’usure. Au total, nous pensons que ce type de cupule ne constitue pas une bonne alternative aux cupules cimentées.

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Accepted: 26 November 1996     

Acetabular cup position and risk of dislocation in primary total hip arthroplasty

Background and purpose — Hip dislocation is one of the most common complications following total hip arthroplasty (THA). Several factors that affect dislocation have been identified, including acetabular cup positioning. Optimal values for cup inclination and anteversion are debatable. We performed a systematic review to describe the different methods for measuring cup placement, target zones for cup positioning, and the association between cup positioning and dislocation following primary THA.

Methods — A systematic search of literature in the PubMed database was performed (January and February 2016) to identify articles that compared acetabular cup positioning and the risk of dislocation. Surgical approach and methods for measurement of cup angles were also considered.

Results — 28 articles were determined to be relevant to our research question. Some articles demonstrated that cup positioning influenced postoperative dislocation whereas others did not. The majority of articles could not identify a statistically significant difference between dislocating and non-dislocating THA with regard to mean angles of cup anteversion and inclination. Most of the articles that assessed cup placement within the Lewinnek safe zone did not show a statistically significant reduction in dislocation rate. Alternative target ranges have been proposed by several authors.

Interpretation — The Lewinnek safe zone could not be justified. It is difficult to draw broad conclusions regarding a definitive target zone for cup positioning in THA, due to variability between studies and the likely multifactorial nature of THA dislocation. Future studies comparing cup positioning and dislocation rate should investigate surgical approach separately. Standardized tools for measurement of cup positioning should be implemented to allow comparison between studies.     

Benefit and risk in short term after total hip arthroplasty by direct anterior approach combined with dual mobility cup

Purpose

No previous reports have described the benefits and risks associated with the dual mobility cup (DMC) in primary THA via direct anterior approach (DAA). The aim of this study was to compare the safety and rate of early postoperative complication of the DAA with the DMC for THA with those of the DAA with a single standard cup, and to investigate the influence of the learning curve of the use of DMC on intra- and perioperative outcomes.

Methods

We retrospectively investigated 60 hips treated in the single-DAA group and 60 hips treated in the dual-DAA group. A primary/secondary outcome variable was the presence of any intra- or perioperative complication within the first 6 months/the operative time and hip function at 6 months postoperatively. We also analyzed influence of the learning curve of the use of DMC on intra- and perioperative outcomes.

Results

No intraoperative complications were observed in either group. One anterior dislocation and one periprosthetic hip fracture were occurred in the single-DAA group. The surgical times in the single-DAA and dual-DAA groups were 112.0 ± 20.9 and 121.0 ± 26.9 min (p < 0.001). There was no significant difference in the 6-month postoperative hip function scores between the two groups. There was no influence of the learning curve of the use of DMC on intra- and perioperative outcomes.

Conclusion

We have demonstrated the short-term safety and lack of inferiority of using the DMC in the DAA compared with the standard single mobility cup.

     

Treatment of recurrent dislocation of total hip arthroplasty using a ligament prosthesis

Recurrent dislocation of total hip arthroplasty (THA) has a poor prognosis when the cause of dislocation cannot be ascertained. We present the successful use of a synthetic ligament prosthesis to treat 4 patients with recurrent posterior dislocation of THA. After an average follow-up period of 28 months, none of the patients had any further episode of dislocation. We believe that this is a simple and low-risk method of treating selected patients and avoids the poor outcome associated with surgery to revise components.     

Treatment of recurrent dislocation associated with impingement after revision total hip arthroplasty

The authors report a case of total hip replacement in which, following several revision operations ending up in a Girdlestone arthroplasty, a patient presented recurrent episodes of posterior dislocation of his total hip prosthesis after revision using an antiprotrusio cage. The main causes for dislocation were anterior impingement of the neck against the anterior wall of the antiprotrusio cage and slackness of the periarticular musculature, due to shortening and reduced femoral offset. In order to avoid further major reconstruction and minimise the risk of infection recurrence, a limited revision operation was performed to address the factors responsible for the instability: the anterior wall of the antiprotrusio cage was removed and an extension module was added to the femoral component. Good stability of the arthroplasty was achieved with this limited procedure.     

Comparison of dual-mobility cup and unipolar cup for prevention of dislocation after revision total hip arthroplasty

Background and purpose — Revision total hip arthroplasty (THA) is associated with higher dislocation rates than primary THA. We compared the risk of dislocation within 6 months and all-cause re-revision during the whole study period using either the dual-mobility cup or the unipolar cup.

Methods — We used a prospective hospital registry-based cohort including all total and cup-only revision THAs performed between 2003 and 2013. The cups used were either dual-mobility or unipolar; the choice was made according to the preference of the surgeon. 316 revision THAs were included. The mean age of the cohort was 69 (25–98) years and 160 THAs (51%) were performed in women. The dual-mobility group (group 1) included 150 THAs (48%) and the mean length of follow-up was 31 (0–128) months. The unipolar group (group 2) included 166 THAs (53%) and the mean length of follow-up was 52 (0–136) months.

Results — The incidence of dislocation within 6 months was significantly lower with the dual-mobility cup than with the unipolar cup (2.7% vs. 7.8%). The unadjusted risk ratio (RR) was 0.34 (95% CI: 0.11–1.02) and the adjusted RR was 0.28 (95% CI: 0.09–0.87). The number of patients needed to treat with a dual-mobility cup in order to prevent 1 case of dislocation was 19. The unadjusted incidence rate ratio for all-cause re-revision in the dual-mobility group compared to the unipolar group was 0.6 (95% CI: 0.3–1.4).

Interpretation — Use of a dual-mobility rather than a unipolar cup in revision THA reduced the risk of dislocation within 6 months.     

The outcomes of constrained total hip arthroplasty for recurrent dislocation of hip hemiarthroplasty

IntroductionThe incidence of hemiarthroplasty dislocation for fracture neck of femurs ranges between 1 and 15% and the one-year mortality is 49- 70%. Revision of hemiarthroplasty to total hip replacement using a constrained liner has shown to improve the morbidity and mortality rates. The aim of the study was to assess whether conversion of dislocated hemiarthroplasty to total hip replacement improve functional and one year mortality.MethodsA retrospective analysis of the number of patients who had recurrent dislocations of hemiarthroplasty for fracture neck of femurs were carried out. The data were obtained from NHFD (National Hip Fracture Database) and internal hospital computer systems (Medway, Theatre notes and PACS) between Dec 2008 and Dec 2020. Patient demographics including age, sex, Abbreviated Mental Test Score (AMTS), functional assessment, mortality at one and two years were documented. The risk factors which led to dislocations such as Parkinsons disease, Cerebrovascular accidents, Musculo-neuropathies and Alzheimer`s disease was also noted.ResultsA total of 3994 patients were admitted during the study period of which 1735 (43.4%) patients had hemiarthroplasty. Fifty-six (3.23%) patients had dislocation of hemiarthroplasty. The mean age was 81.4 years (range – 61 to 95). There were 40 (71.4%) females and 16 males (28.6%). The average AMTS score was 5.3. All 56 patients had closed manipulative reduction under anaesthesia within in 12 h of admission. Thirty-one patients (55.4%) went on to have recurrent dislocations of which 18 patients (58.4%) had total hip replacement using captive cup, 6 patients (19.4%) had open reduction,3 patients (9.7%) had excision arthroplasty procedure and four patients (12.5%) had no intervention, Eighteen patients who had total hip replacement with constrained captive for followed up to a minimum of two years (range2- 12 years). There were no intraoperative complications, dislocation or periprosthetic fractures in the follow up period. There was no mortality at the end of two years of follow up in this group, two-year mortality for the patients with alternative management for dislocated hemiarthroplasty was 76.67.ConclusionTreatment of recurrent hemiarthroplasty dislocation by revising to a total hip replacement with a constrained liner gives good functional and mortality outcomes.     

Uncemented primary press-fit total hip arthroplasty: a 3 to 6 years of experience

PURPOSE: To analyse the 3 to 6 years' clinicoradiological outcome of 45 uncemented total hip arthroplasties performed in 37 patients using cementless Spotorno stem and St Nabor cup. METHODS: The main indications for surgery were avascular necrosis of the femoral head and rheumatoid arthritis. Younger patients with good bone quality and a trumpet-shaped femur were eligible. A single surgeon performed all the operations using a posterolateral approach. Patients were reviewed at 6 weeks, 3 months, 6 months, and yearly thereafter. The clinical status was recorded using the Harris Hip Score. All radiographs were analysed by 2 independent blinded observers on 2 separate occasions. RESULTS: The mean follow-up period was 49 months and the mean Harris Hip Score at the latest follow-up was 94. Osseointegration in the form of trabeculae running from the endosteum to the prosthesis surface along with tropism of the calcar was evident in 73% of the hips. None of the remaining hips showed any continuous radio-opaque lines suggestive of a lack of bone ongrowth. Patients with endosteal condensation had better Harris Hip Scores. Intra-operative stability of the implants could fairly predict outcome. CONCLUSION: Initial clinicoradiological results of uncemented total hip arthroplasty are promising in younger patients with good bone quality and a trumpet-shaped femur.     

The use of a dual mobility cup in the management of recurrent dislocations of hip hemiarthroplasty

Background

Dislocation is one of the most frequent causes of failure of hemiarthroplasties of the hip, which is the most common treatment for femoral neck fractures in elderly patients. A revision with conversion to total hip arthroplasty is the gold standard in case of failure of closed reduction: however, the use of standard or modular components shows variable outcomes. The use of a dual mobility cup has been evaluated in patients with unstable implants, given the good outcomes obtained in primary and revision surgery. The aim of this study was to assess the results of revisions by dual mobility cups in unstable hemiarthroplasties.

Materials and methods

Thirty-one patients (mean age 75.4 years) were retrospectively evaluated between 2006 and 2010 after conversion to total hip arthroplasty with dual mobility cups for recurrent dislocations. The mean number of dislocations was 2.6 (range 2–5). The evaluation was performed by the American Society of Anesthesiologists physical function score (ASA) and the Harris hip score, and several radiologic criteria.

Results

The mean follow-up was 3.8 years. No recurrence of dislocation was recorded. The ASA score remained unchanged, and the mean Harris hip score improved from 62.2 before dislocation to 76.0 points postoperatively.

Conclusions

Dual mobility cups may be a useful option in the treatment of a hemiarthroplasty dislocation. No risk of a new revision due to instability after insertion of dual mobility cups resulted in our experience, and this option may be strongly considered in cases of revisions of unstable hemiarthroplasties. Level of evidence IV.

     

Bipolar hip arthroplasty for recurrent dislocation after total hip arthroplasty. A report of three cases.

Recurrent dislocation after total hip arthroplasty is often a difficult complication to manage. Bipolar prostheses may be useful in these cases because motion can occur at two bearing surfaces and thus permit the greater range of motion necessary to dislodge the head from the acetabulum. The bipolar head is also larger than a conventional total hip femoral component, so a greater volume must be displaced from the acetabulum for dislocation to occur. Three patients with recurrent dislocation of a total hip prosthesis were successfully treated by conversion to bipolar devices after failure of multiple surgical procedures and treatment even with braces.