Cementless dual-mobility cup in total hip arthroplasty revision

Purpose

Dislocation is a frequent complication in total hip arthroplasty (THA) revision. Cup fixation is the second concern. In order to know outcomes at two years, we prospectively followed a continuous series of 78 patients to demonstrate that cementless dual-mobility cup (DMC) used in revision THA is safe as regards dislocation risk and bone fixation.

Method

We enrolled 78 consecutive patients (79 cases) in a prospective study. Mean interval between index surgery and revision was 12.9 years. Mean age at revision was 75.5 years. Two types of cementless DMC were used: a standard DMC in 68 cases with low-grade bone defect (Paprosky grade 1 and 2), and a specific design reconstruction DMC in 11 cases with severe bone loss (Paprosky grade 3).

Results

At two years of follow-up, 68 patients were reviewed; four were lost to follow-up., and six patients were deceased. We identified three types of situations at risk:standard risk (33 cases), Paprosky grade 1 or 2; medium risk (37 cases), revision for recurrent instability (21), periprosthetic fractures (14) or severe loosening Paprosky grade 3 without femorotomy (2); high risk (nine cases), revision for severe loosening with a femorotomy. One (1.3 %) patient dislocated her hip at one month without recurrence. Revision rate for dislocation was 0 %; two (2.7 %) early mechanical failures occurred.

Conclusion

Considering outcomes of this series, cementless DMC can be suggested in THA revision surgery.     

Femoral neuropathy caused by reinforcement ring malposition and extruded bone-cement after revision total hip arthroplasty

Femoral neuropathy occurred after revision total hip arthroplasty as a result of pressure from the reinforcement ring and extruded bone-cement (polymethyl methacrylate). Four weeks after the revision surgery, we performed an operation to decompress the femoral nerve and allow neurolysis. Neuropathy improved gradually after the subsequent surgery.     

One-stage revision of infected cemented total hip arthroplasty

A prospective study of a one-stage revision of infected cemented total hip arthroplasty was carried out in 102 consecutive cases using acrylic cement with 0.5 g of gentamicin in each 40 g pack as well as systemic and oral antibiotics. Thirty percent had a sinus tract at some stage before the revision. The most common infecting organism was coagulase-negative Staphylococcus, either as a pure growth or in combination with other organisms. The success rate was 91%, with an average follow-up study of three years and two months. The infection persisted in 9% of the cases. In three cases, infection was correlated with some aspect of the revision technique. The method gave a higher success rate than that obtained without the use of an antibiotic-loaded acrylic cement. Combined systemic and oral use of antibiotics appears to reduce the recurrence rate still further.     

Displacement of a cemented socket after reduction of a dislocated total hip arthroplasty

Acute displacement of the cemented acetabular component of a hip arthroplasty after attempted reduction of a dislocation is described. The causes of displacement of the socket, which was not radiologically loose, are discussed. Potential causes include impingement of the femoral head and the ceramic screw head overhanging the acetabular bone, which was used to fix the bone graft.     

Ganz reinforcement ring for reconstruction of acetabular defects in revision total hip arthroplasty

BACKGROUND: In revision total hip arthroplasty, bone loss due to loosening and migration of the acetabular component makes fixation of a new implant difficult. The purpose of this study was to evaluate the clinical and radiographic outcomes of the use of the Ganz reinforcement ring with nonstructural allograft in the reconstruction of acetabular defects. METHODS: Sixty-one acetabular revisions performed with use of the Ganz reinforcement ring and nonstructural allograft, between 1989 and 1992, in fifty-seven patients with aseptic loosening met our selection criteria. Eleven hips in eleven patients were lost to follow-up, leaving fifty hips available for evaluation five years or more following surgery. According to the American Academy of Orthopaedic Surgeons classification, twenty-four acetabular defects were Type II, twenty-four were Type III, and two were Type IV. Clinical and radiographic evaluations were carried out at a mean of six and nine years after surgery. Twelve more patients were lost to follow-up before the most recent evaluation. RESULTS: The mean Merle d'Aubigné composite score increased significantly compared with the preoperative score (p < 0.001). There were seven failures: six cases of aseptic loosening and one case of septic arthritis. Graft incorporation and bone remodeling occurred in all hips but three in which the ring fixation had been inadequate at the time of surgery. The Kaplan-Meier survivorship rate, with use of revision or loosening of the component as the criterion of failure, was 81% at ten years. Inadequate fixation of the implant at the time of surgery was the only multivariate predictor of failure (p = 0.003). CONCLUSIONS: Patients treated with acetabular revision with a Ganz reinforcement ring had reconstitution of periacetabular bone stock as well as good clinical and radiographic results, provided that the ring had been fixed adequately at the time of surgery. This procedure may not be the preferred approach for reconstructing segmental defects of the medial wall or pelvic discontinuity.     

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.     

External wear of the polyethylene socket in cemented total hip arthroplasty

We examined 59 cemented high density polyethylene sockets removed at revision hip arthroplasty. Of these 19 showed areas of wear between the outside of the socket and the acetabular bone. This was associated with lack of acrylic cement in those areas and was also related to the depth of the wear on the articulating surface of the socket. It is suggested that, in some cases, changes at the bone-cement junction are secondary to socket loosening and abrasion against the bone of the acetabulum, rather than to particles migrating from the metal-polyethylene interface. It is therefore important that impingement of the neck of the femoral stem on the edge of the cup be avoided and that, when the socket is inserted, it is not in direct contact with the bone.     

Outcomes of dual-mobility acetabular cup for instability in primary and revision total hip arthroplasty

Background

The concept of a dual-mobility hip socket involves the standard femoral head component encased in a larger polyethylene liner, which in turn articulates inside a metal shell implanted in the native acetabulum. The aim of this study was to assess outcomes from using a Serf Novae^® Dual Mobility Acetabular cup (Orthodynamics Ltd, Gloucestershire, UK) to address the problem of instability in primary and revision total hip arthroplasty (THA).

Materials and methods

A retrospective review was carried out of all hip arthroplasties performed in a District General Hospital utilising the dual-mobility socket from January 2007 to December 2012. Clinical and radiological outcomes were analysed for 44 hips in 41 patients, comprising 20 primary and 24 revision THA. The average age of the study group was 70.8 years (range 56–84 years) for primary and 76.4 years (range 56–89 years) for revision arthroplasty. Among the primary THA, always performed for hip osteoarthritis or in presence of osteoarthritic changes, the reasons to choose a dual mobility cup were central nervous system problems such as Parkinson’s disease, stroke, dementia (10), hip fracture (5), failed hip fracture fixation (2), severe fixed hip deformity (2) and diffuse peripheral neuropathy (1). The indications for revisions were recurrent dislocation (17), aseptic loosening with abductor deficiency (4), failed hemiarthroplasty with abductor deficiency (2) and neglected dislocation (1).

Results

At a mean follow-up of 22 months (range 6–63 months), none of the hips had any dislocation, instability or infection and no further surgical intervention was required. Radiological assessment showed that one uncemented socket in a revision arthroplasty performed for recurrent dislocation had changed position, but was stable in the new position. The patient did not have complications from this and did not need any surgical intervention.

Conclusions

Even though postoperative hip stability depends on several factors other than design-related ones, our study shows promising early results for reducing the risk of instability in this challenging group of patients undergoing primary and revision hip arthroplasty.

Level of evidence

IV.     

Long-term results after cemented revision of the femoral component in total hip arthroplasty

The need for revision total hip arthroplasty has been increasing. The early results have been poor, and different revision techniques have been introduced. We report our results of 84 consecutive cemented first-time revisions of femoral components performed from 1981 through 1988 using a long-stem revision component. The average time to follow-up was 11.4 years (range, 7.9-15.0 years). Patients with 47 revisions had died; 2 of these had been rerevised. Two additional patients were lost to follow-up for other reasons. Of the living patients, 12 had been rerevised, leaving 23 patients (23 hips) for complete follow-up evaluation, including clinical and radiographic assessment. Of 23 patients, 15 reported no pain, 4 had only slight pain, and 4 had more severe pain. In 4 cases, there were definite radiographic signs of loosening of the femoral component. Kaplan-Meier survivorship analysis showed an overall 10-year survival of the femoral component of 77.9%. Using rerevision because of aseptic loosening or definite radiographic loosening as endpoint, the 10-year survival was 80.7%. Simple recementation is well indicated in elderly patients with only minor bone loss.     

The role of cemented stems in revision total hip arthroplasty

Cemented stems in revision total hip arthroplasty were reported to have unacceptably high rates of mechanical failure in early publications. This led to the development and current popularity of cementless revision stems, which have shown good results. However, there are still circumstances when cemented femoral revision can provide immediate, reliable fixation with comparatively good results, and this technique remains an important part of the arthroplasty surgeon's armamentarium. In this review, we will discuss the role of cemented stems in revision total hip arthroplasty, focusing on cement-in-cement revision, and impaction bone grafting of the femur.     

Results of cementless revision for failed cemented total hip arthroplasty

The goals of revision total hip arthroplasty (THA) are to reestablish and maintain stable implant fixation. Based upon promising early results in primary THA, porous-surfaced implants designed for bone ingrowth fixation are being increasingly used in hopes of more successfully achieving these goals than has been the case using cement. One hundred and sixty such revisions were followed for a mean of 4.4 years, with specific reference to implant fixation. Roentgenographic evaluation of implant fixation suggested four categories of femoral and acetabular components: (1) bone ingrown, (2) stable fibrous encapsulation, (3) questionable, with signs of impending instability, or (4) definitely unstable implant migration, indicative of the need for rerevision. Not surprisingly, success in achieving and maintaining stable implant fixation following revision THA is dependent upon component design, surgical technique, and preexistent bone stock damage. This classification according to bone stock damage should be borne in mind when critically evaluating the results from various revision series.     

髋关节置换术后失败原因分析

[目的]分析髋关节置换术后接受翻修手术的病例,探讨髋关节置换术后不同时期失败的原因和特点.[临床资料]回顾性分析1995年6月～2005年6月间髋关节置换术后失败接受翻修手术的病例78例.其中全髋置换术后翻修42例,股骨头置换术后翻修36例.初次髋关节置换术后5年以内翻修的共36例,5年以上翻修的42例.[结果]在早期失败(5年以内)的病例中,失败原因主要是感染(16例),其次是假体无菌性松动,髋臼磨损和机械性失败.在晚期失败(5年以上)的病例中,失败原因主要为无菌性松动,髋臼磨损.[结论]感染是全髋关节置换术后早期松动的主要原因之一.而全髋关节置换术后的主要原因是晚期无菌性松动.     

Thromboembolic complications after total hip arthroplasty

Thromboembolic disorders are worrisome complications following total hip arthroplasty, and the best way to address such complications is by prevention. Several regimens have been advocated to decrease the risk of thromboembolic disorders. A combination of pharmacologic and nonpharmacologic measures helps reduce the incidence of deep venous thrombosis and, hence, pulmonary embolization.     

Early radiographic results comparing cemented and cementless total hip arthroplasty

In a randomized clinical trial of cemented and cementless total hip arthroplasty, 147 patients (76 cemented, 71 cementless) have had a minimum 4-year clinical and radiographic follow-up evaluation. No revisions have been done in either group. Two cemented acetabular components were considered definitely loose and 18 were probably loose; 7 cemented stems were possibly loose at last follow-up examination. One cementless socket was considered unstable. Although cementless femoral component subsidence occurred in 10 cases, the sinkage always stabilized within 6 months, and no stem was considered unstable at last follow-up examination. Significant femoral bone resorption was rare, and so-called “spot welds” were uncommon using this titanium stem. Distal cortical hypertrophy was common, but the cause is uncertain. Osteolysis was seen around 10 cementless and 6 cemented sockets. A small area of lysis occurred in the proximal medial femoral neck in 15 cemented stems and 1 cementless stem. No cases of distal femoral lysis were seen in either group. Despite excellent clinical results with no difference between groups, the high rate of early radiographic failure of this metal-backed acetabulum should preclude its use. Osteolysis will continue to be a problem in both groups, and its prevention should remain the focus of future studies.     

Periprosthetic bone loss after cemented total hip arthroplasty

In this prospective 5-year study, we determined the periprosthetic bone loss after cemented total hip arthroplasty (THA) in 15 patients using dual energy X-ray absorptiometry (DXA). A reduction in the periprosthetic bone mineral density (BMD) of 5-18% occurred in all Gruen regions, or regions of interest (ROI), during the first 3 months after THA. The bone loss continued up to 6 months in almost all ROIs. From 1 to 5 years, we found only minor changes in BMD in periprosthetic bone. After the follow-up, the mean greatest bone loss (26%) was seen in the femoral calcar area. The reduction in mean BMD was 5% in men, and 16% in women. The lower the preoperative BMD, the higher was the postoperative bone loss. We found that after the phase of acute bone loss, further loss was minimal, reflecting merely the normal ageing of bone after uncomplicated THA.     

Femoral shaft fractures after cemented total hip arthroplasty

Summary Thirty-seven femoral shaft fractures occurred in 2360 cemented hip arthroplasties carried out between 1971 and 1989 at varying intervals after operation (average 3.7 years). Three types of fracture were recognised and treatment depended on the type, as did the prognosis. Good results were obtained in 70% of the cases.

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Résumé Sur une série consécutive de 2360 prothèses totales de hanche cimentées, réalisées dans notre hôpital de 1971 à 1989, on a observé 37 fractures de la diaphyse fémorale. Ces fractures sont survenues après un délai variable (3,7 ans en moyenne). Le pronostic de la consolidation de la fracture et de l'avenir de la prothèse dépend du type de la fracture, évalué selon la classification de Johansson. Le type II a été le plus fréquent (51%), suivi par le type III (30%) et le type I (19%). Le traitement a été différent selon le type de la fracture, avec 70% de bons résultats.

     

Walking efficiency after cemented and noncemented total hip arthroplasty

Clinical evaluation using the Harris hip score has been supplemented with analysis of walking capacity before and after total hip arthroplasty (THA). Twenty patients were studied, ten of whom were treated with a cemented Charnley prosthesis and ten with a noncemented HP-Garches prosthesis. Tests were performed preoperatively and three, six, and 12 months postoperatively. Harris hip scores increased from a mean of 35 points preoperatively to 85 one year after surgery. Patients with a Charnley prosthesis had significantly higher scores than those with an HP-Garches prosthesis. The hip score did not differ between patients with uni- and bilateral disease. Mean maximum walking speed before surgery was 62 m/minute and increased to 80 m/minute one year after THA. The mean oxygen cost preoperatively was 0.267 ml/kg/m and decreased to 0.221 ml/kg/m one year after surgery. A weak correlation was found between differences in Harris hip scores and the corresponding oxygen cost. The onset of and the recovery from complications as well as differences between patients with uni- and bilateral diseases were reflected in changes in oxygen cost in contrast to clinical scores. The measurement of oxygen cost gave objective and valuable information about walking efficiency after THA.     

Factors affecting socket fixation after cemented revision

Summary. Factors influencing the radiographic outcome of revised cemented sockets have been investigated in 360 cases; 70 with radiological signs of failure were analysed. The acetabular bone stock at revision and preparation of the acetabular floor were the two factors which had a significant influence on the outcome. The thickness of the cement mantle around the socket also had an influence. Young patients were at a higher risk of failure. The use of a flanged socket and an acetabular cement pressuriser appeared to improve the radiographic result, but this was not statistically significant.

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Résumé. Nous étudions les facteurs influen*ant l’évolution radiologique des cupules cimentées après changement. Dans cette étude, 360 cupules cimentées dont 70 présentant un descellement radiologique ont eu à une analyse statistique. Le capital osseux de l’acétabulum et la préparation du fond du cotyle lors du changement de la prothèse se sont révélés être les deux facteurs ayant une influence hautement significative (p = 0.0001) sur l’évolution de ces cupules. Nous avons aussi constaté que l’épaisseur du manteau de ciment autour de la cupule influence le pronostic. En outre, les patients jeunes présentent un risque élevé de descellement radiologique. L’utilisation du pressurisateur à ciment et des cupules avec rebord tend à améliorer l’évolution radiologique, mais de fa*on non significative statistiquement.

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Accepted: 12 July 1996     

骨水泥型与非骨水泥型人工全髋关节置换术的比较

目的评价骨水泥型和非骨水泥型人工全髋关节置换术的术中、术后临床效果。方法对52例患者(54髋)进行人工髋关节置换治疗,其中骨水泥组20例(20髋),非骨水泥组32例(34髋)。术后随访进行髋关节Harris评分、自主功能恢复Parker评分,并观察术后死亡率、假体翻修率及其他并发症的发生情况。结果与骨水泥型组相比,非骨水泥型组术中手术时间短、失血量少,两组差异有显著性(P0.05)。骨水泥组1例患者住院时出现深静脉血栓形成,非骨水泥组有3例住院时出现深静脉血栓形成。骨水泥组置换后3个月,14例患者可独立行走,5例需助步器辅助行走,1例仅能活动(卧床活动);非骨水泥组23例患者可独立行走,9例需助步器辅助行走。置换后1年,在患者髋关节Harris评分和患者自主功能恢复Parker评分方面,两组之间均无显著差异。置换后3年,骨水泥组有4例翻修(均为假体松动),翻修率20%。而非骨水泥组仅有3例翻修(均为假体松动),翻修率9.37%,但两组之间差异无显著性(P0.05)。另外,随访期间骨水泥组有1例患者死亡。结论应用非骨水泥假体可明显降低全髋关节置换术的手术时间和失血量。随访期内骨水泥型和非骨水泥型双动头假体置换术的临床疗效无显著差异。     

The use of dual-mobility components in total hip arthroplasty

Dual-mobility hip components provide for an additional articular surface, with the goal of improving range of motion, jump distance (ie, vertical or inferior head displacement required for dislocation), and stability of the total hip arthroplasty. A large polyethylene head articulates with a polished metal acetabular component, and an additional smaller metal head is snap-fit within the polyethylene. New components have recently been released for use in North America. Although these devices are routinely used in some European centers for primary hip arthroplasty, their greatest utility may be to manage recurrent dislocation in the setting of revision hip arthroplasty. Several small retrospective series have shown satisfactory results for this indication at short- to midterm follow-up. Polyethylene wear and intraprosthetic dislocation are concerns, as is the lack of long-term data. Caution is thus advised in the routine use of dual-mobility components in primary and revision total hip arthroplasty.