Cementless Components Research Articles

Outcome of One-stage Cementless Exchange for Acute Postoperative Periprosthetic Hip Infection

Acute postoperative infection after total hip arthroplasty (THA) is typically treated with irrigation and débridement and exchange of the modular femoral head and acetabular liner. Given a rate of failure exceeding 50% in some series, a one-stage exchange has been suggested as a potential alternative because it allows more thorough débridement and removal of colonized implants. To date, most studies published on the one-stage exchange have used microbe-specific antibiotic-laden bone cement with only one small single-institution series that reported outcomes after a cementless one-stage exchange. We determined whether a one-stage cementless exchange for treating acute postoperative infection after THA would result in infection control with component retention and normalization of infection markers. We retrospectively identified 27 patients who underwent a one-stage exchange performed for an acute (≤6 weeks) postoperative infection after THA from April 2004 to December 2009. Primary cementless components were used both at the time of the index arthroplasty and the revision in all patients. Surgery was followed by a 6-week course of culture-specific antibiotics in all patients and a variable course of oral antibiotics. Our primary outcome was retention of the implants at most recent followup and our secondary outcome was normalization of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) at most recent followup. Patients were followed until failure or a minimum of 2 years. At a minimum followup of 27 months (mean, 50 months; range, 27-89 months), 19 of the 27 patients (70%) retained their implants but four required further operative débridement with component retention at a mean of 3 weeks (range, 2-6 weeks) to obtain control of infection. Thus, an isolated single-stage exchange was successful in 15 of the 27 patients (56%). Eight patients (30%) ultimately had a two-stage exchange for persistent infection; seven of these patients required no further surgery, whereas one patient required a second two-stage exchange. Of those patients retaining their prosthesis after one-stage exchange and tracked with ESR and CRP, four (33% [four of 12]) had elevated values without other signs or symptoms of recurrent infection. For acute postoperative infection after primary THA, a one-stage cementless exchange allowed 70% of patients to retain their implants at most recent followup. Of those patients who ultimately went on to a two-stage exchange, only one required a second two-stage exchange. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The assessment of total hip arthroplasty

•. Technical aspects of total hip arthroplasty (THA), such as component position or the quality of the cement mantle, can be assessed post-operatively and may affect long-term outcome.•. The radiographic appearance of THA changes over time according to well-defined biomechanical and biological principles.•. There are fundamental differences between the design principles and subsequent behaviour of cemented and cementless components.•. Microscopic wear debris (particularly polyethylene debris) causes osteolysis and may lead to loosening, implant migration or fracture.•. Identification of important radiographic features may predict failure and allow timely and appropriate intervention.Soft tissue abnormalities related to THA can be assessed with ultrasound or MRI.Total hip arthroplasty (THA) is now a common surgical procedure. Radiologists are increasingly required to assess the prosthetic hip construct, either in the immediate post-operative period or later in the life of the patient, often years or decade...

Cemented Acetabular Components May Be More Reliable Than Cementless Components Beyond the First Postoperative Decade

Cemented Acetabular Components May Be More Reliable Than Cementless Components Beyond the First Postoperative Decade

Acetabular Components in Total Hip Arthroplasty: Is There Evidence That Cementless Fixation Is Better?

The use of cementless acetabular components in total hip arthroplasty has gained popularity over the past decade. Most total hip arthroplasties being performed in North America currently use cementless acetabular components. The objective of this systematic review and meta-analysis was to compare the survivorship and revision rate of cemented and cementless acetabular components utilized in total hip arthroplasty. A primary literature search in PubMed identified 3488 articles, of which 3407 did not meet the inclusion criteria and were excluded. Only English-language articles on either the survivorship or revision rate of primary total hip arthroplasty at a minimum of ten years of follow-up were included. The present study analyzed forty-five articles reporting the long-term outcome of cementless acetabular components, twenty-nine reporting the outcome of cemented acetabular components, and seven comparing cemented and cementless acetabular components. Meta-analysis (with a random-effects model) was performed on the data from the seven comparative studies, and study-level logistic regression analysis (with a quasibinomial model) was performed on the pooled data on the eighty-one included articles to determine a consensus. The studies were weighted according to the number of total hip arthroplasties performed. The meta-analysis did not reveal any effect of the type of acetabular component fixation on either survivorship or revision rate. The regression analysis revealed the estimated odds ratio for survivorship of a cemented acetabular component to be 1.60 (95% confidence interval, 1.32 to 2.40; p = 0.002) when adjustments for factors including age, sex, and mean duration of follow-up were made. The preference for cementless acetabular components on the basis of improved survivorship is not supported by the published evidence. Although concerns regarding aseptic loosening of cemented acetabular components may have led North American surgeons toward the nearly exclusive use of cementless acetabular components, the available literature suggests that the fixation of cemented acetabular components is more reliable than that of cementless components beyond the first postoperative decade.

Atypical Femoral Fractures: What Do We Know About Them?

Background: The use of cementless acetabular components in total hip arthroplasty has gained popularity over the past decade. Most total hip arthroplasties being performed in North America currently use cementless acetabular components. The objective of this systematic review and meta-analysis was to compare the survivorship and revision rate of cemented and cementless acetabular components utilized in total hip arthroplasty. Methods: A primary literature search in PubMed identified 3488 articles, of which 3407 did not meet the inclusion criteria and were excluded. Only English-language articles on either the survivorship or revision rate of primary total hip arthroplasty at a minimum of ten years of follow-up were included. The present study analyzed forty-five articles reporting the long-term outcome of cementless acetabular components, twenty-nine reporting the outcome of cemented acetabular components, and seven comparing cemented and cementless acetabular components. Meta-analysis (with a random-effects model) was performed on the data from the seven comparative studies, and study-level logistic regression analysis (with a quasibinomial model) was performed on the pooled data on the eighty-one included articles to determine a consensus. The studies were weighted according to the number of total hip arthroplasties performed. Results: The meta-analysis did not reveal any effect of the type of acetabular component fixation on either survivorship or revision rate. The regression analysis revealed the estimated odds ratio for survivorship of a cemented acetabular component to be 1.60 (95% confidence interval, 1.32 to 2.40; p = 0.002) when adjustments for factors including age, sex, and mean duration of follow-up were made. Conclusions: The preference for cementless acetabular components on the basis of improved survivorship is not supported by the published evidence. Although concerns regarding aseptic loosening of cemented acetabular components may have led North American surgeons toward the nearly exclusive use of cementless acetabular components, the available literature suggests that the fixation of cemented acetabular components is more reliable than that of cementless components beyond the first postoperative decade.

Cemented polyethylene and cementless porous-coated acetabular components have similar outcomes at a mean of seven years after total hip replacement

The aim of this prospective randomised study was to compare the clinical and radiological results of a cemented all-polyethylene Ultima acetabular component with those of a cementless porous-coated acetabular component (PFC) following total hip replacement (THR). A total of 287 patients received either a polyethylene acetabular component (groupA) or a cobalt-chromium porous-coated component (group B) with an identical cemented femoral component and 28 mm cobalt-chromium head, thus making it the largest study of its type. Patients were evaluated radiologically and clinically using the Harris hip score (HHS). Group A comprised 183 patients (73 male, 110 female) with a mean age of 71.3 years (55 to 89). Group B comprised 104 patients (48 male, 56 female) with a mean age of 69.8 years (56 to 89). A total of 16 patients (13 in Group A, three in Group B) did not have post-operative data for analysis. The mean follow-up in group A was 7.52 years (0.4 to 15.0) and in Group B 7.87 years (0.5 to 14.0). At final follow-up the mean HHS was similar between groups A and B (74.5 (25 to 100) and 78.0 (37 to 100), respectively; p = 0.068). The total number of revisions for any cause was 28, 17 of which were in group A and 11 in group B. The ten-year survivorship was 86.8% (95% confidence interval (CI) 78.4 to 92.1) and 89.2% (95% CI 78.3 to 94.8) for groups A and B, respectively (log-rank p-value = 0.938). A total of 20 cemented and two cementless acetabular components had evidence of acetabular radiolucencies or acetabular component migration at last follow-up (p = 0.001). These results indicate that patients with a cemented all-polyethylene and cementless porous-coated polyethylene lined acetabular component have similar long-term clinical outcomes.

Cost Comparison of Cementless Versus Cemented Hemiarthroplasty for Displaced Femoral Neck Fractures

Hip hemiarthroplasties are frequently performed for displaced femoral neck fractures. The purpose of this study was to identify the costs associated with cementless and cemented hemiarthroplasties, compare operative times, and identify complications. The hypothesis was that cementless hemiarthroplasties cost less than cemented hemiarthroplasties, require less operative time, and have fewer perioperative complications. A retrospective review was conducted of 2 surgeons' patients admitted for displaced femoral neck fractures between 2006 and 2010. Group 1 included 45 patients who underwent monopolar hemiarthroplasties with cementless femoral components via a standard posterior approach by a single surgeon. Group 2 included 49 patients who underwent monopolar hemiarthroplasties with cemented femoral components via a modified lateral approach by a single surgeon. Surgical and anesthesia times and the cost of implants and accessories were recorded. The cost for cementless components was $3275.60 (femoral stem, $2800; monopolar head, $400; sleeve, $75.60), whereas the cost of cemented components was $3694.47 (femoral stem, $1800; monopolar head, $400; sleeve, $75.60, 3 Simplex with tobramycin cement packets, $1221; cement mixer/irrigator with tip/centralizer and plug/pressurizer, $197.87), a cost savings of 12.7% ($418.87). Operative time was significantly reduced in group 1 vs group 2 (mean, 32.9 vs 56.1 minutes, respectively; P<.01). Anesthesia time was also significantly reduced in group 1 (mean, 82.3 vs 102.9 minutes, respectively; P<.01). The difference in mean anesthetic times demonstrates an overall cost savings of 18.6%, or $1161.30. No difference in complications was noted between the groups perioperatively. Regional cost variances, vendor-hospital contracts, and surgeons' operative times are factors that may influence cost savings. This study demonstrates significantly lower operative and anesthetic times and observable cost savings with cementless femoral implants.

Reply to Letter to the Editor: Treatment of Early Postoperative Infections After THA: A Decision Analysis

We appreciate the opportunity to reply to the comments of Drs Wolf, Leithner, and Clar. Their comments regarding our study [1] are centered on the concept of applying risk stratification for patients being treated for an infected THA during the early postoperative period. They state that our study does not account for patient-related risk factors in its analysis and that we overlooked two studies [2, 3] that might have contributed insight into this element of the analysis. As is known, the success or failure of any medical intervention in general, and the treatment of periprosthetic joint infections in particular, are predicated on many factors. The concept of Bayes’ theorem and a priori risk are highlighted in this clinical scenario and are mentioned in our article. We believe strongly that risk stratification has an extremely important role in deciding a treatment regimen. What Wolf et al. fail to mention is that these are just concepts. Even for common orthopaedic procedures such as THA, the elements that lead to meaningful risk stratification are not fully understood or implemented, and moreover, in complex clinical scenarios such as with a periprosthetic joint infection, these elements and their application become even more challenging. The two studies referenced by Wolf et al. [2, 3] serve to highlight the lack of information on this concept in the literature. The study by McPherson et al. [3] reports on a staging system for patients with chronic infection who have had a resection arthroplasty as the first stage of a two-stage procedure. McPherson et al. report that the staging system they used correlated with the ultimate ability to successfully reimplant a prosthesis. Although this study provides insight into the specific clinical scenario of patients with a resection arthroplasty after a chronic infection awaiting a second-stage reimplantation, this does not in apply to the hypothetical clinical scenario of our patient 3 weeks after THA. In addition, although elements of this staging system might be useful for acute postoperative infections, the study by McPherson et al. [3] cannot be applied to fundamentally different clinical scenarios. In the study by DeMan et al. [2], no elements of risk stratification are provided, but rather this is a study reporting on the results of a specific algorithmic approach to infection. In addition and similar to the study by McPherson et al., DeMan et al. do not report on the outcomes of acute postoperative infection, but rather a combination of acute and chronic infections they treated. They also report the use of antibiotic cement for fixation of the femoral and acetabular components in approximately half of their cohort. The use of antibiotic cement for the single-stage approaches is mentioned specifically in our study with reported infection control rates. In addition, we discussed the concept of single- and two-stage exchanges being performed using cementless components. The study by De Man et al. does not apply to the clinical scenario presented by an acute postoperative infection. Although we fundamentally agree with Wolf et al. in their desire to use risk stratification in the analysis of different treatment algorithms, there are no published data that establish these parameters. We agree that prospective studies are warranted to better answer this question.

Cementless total hip arthroplasty in rheumatoid arthritis: a systematic review of the literature

BackgroundCompromised rheumatic bone is a potential risk factor for mechanical complications in cementless total hip arthroplasty (THA) in cases of rheumatoid arthritis (RA). Increased rates of intra-operative fractures, component migration and (early) aseptic loosening are to be expected. Despite this, cementless THA is performed in cases of RA.MethodsA literature search on cementless THA in RA was performed in EMBASE (1993–2011), Medline (1966–2011) and the Cochrane Library. A systematic review was conducted with a special emphasis on mechanical complications.ResultsTwenty-three case series and five studies of implant registries were included. Acetabular fractures and/or migration of the cup were reported in 9 out of 22 studies of the cup. Proximal femoral fractures and/or subsidence of the stem were reported in 14 out of 20 studies of the stem. Six studies compared failure rates of uncemented and cemented components due to aseptic loosening. The overall failure rate ratio (uncemented/cemented) for the cup was 0.6 (95% CI: 0.14–2.60) and for the stem 0.71 (95% CI: 0.06–8.55), both favoring uncemented fixation. The failure rates in case series without a control group were compared to the NICE criteria (failure rate/1). The overall failure rate for the cup was 0.97 (95% CI: 0.50–1.88) and for the stem 0.79 (95% CI: 0.44–1.41). Failure rates of aseptic loosening of higher than 1 (favoring cemented fixation) were reported in 6 out of 26 studies of the cup and in 2 out of 25 studies of the stem. In all these studies, the inferior implant designs were blamed, and not the type of fixation or the quality of the bone.ConclusionsDespite substantial rates of mechanical stem complications, no evidence was found to establish that cementless components perform less well than cemented components. The results justify the use of cementless THA in RA patients.

Bone remodelling around a cementless glenoid component

Post-operative change in the mechanical loading of bone may trigger its (mechanically induced) adaptation and hamper the mechanical stability of prostheses. This is especially important in cementless components, where the final fixation is achieved by the bone itself. The aim of this study is, first, to gain insight into the bone remodelling process around a cementless glenoid component, and second, to compare the possible bone adaptation when the implant is assumed to be fully bonded (best case scenario) or completely loose (worst case scenario). 3D finite element models of a scapula with and without a cementless glenoid component were created. 3D geometry of the scapula, material properties, and several physiological loading conditions were acquired from or estimated for a specific cadaver. Update of the bone density after implantation was done according to a node-based bone remodelling scheme. Strain energy density for different loading conditions was evaluated, weighted according to their frequencies in activities of daily life and used as a mechanical stimulus for bone adaptation. The average bone density in the glenoid increased after implantation. However, local bone resorption was significant in some regions next to the bone-implant interface, regardless of the interface condition (bonded or loose). The amount of bone resorption was determined by the condition imposed to the interface, being slightly larger when the interface was loose. An ideal screw, e.g. in which material fatigue was not considered, was enough to keep the interface micromotions small and constant during the entire bone adaptation simulation.

Extended sagittal saw cut significantly reduces fracture load in cementless unicompartmental knee arthroplasty compared to cemented tibia plateaus: an experimental cadaver study

Periprosthetic tibial plateau fractures represent a rare but serious complication in unicompartmental knee arthroplasty and are associated with extended sagittal tibial bone cuts. These can occur during the surgery, weaken the posterior cortex of the tibia and are associated with periprosthetic tibial plateau fractures. Although excellent long-term results have been reported with cemented unicompartmental knee arthroplasty, there is high interest in cementless fixation. The aim of the study was to compare fracture loads of cementless and cemented unicompartmental knee arthroplasty. Tibial components of the Oxford Uni were implanted in six paired fresh-frozen tibiae with a defined extended saw cut (10°) at the dorsal cortex of each specimen. In one set, surgery was performed with cement fixation, and in the other, cementless components were implanted. Vertical loads were then applied under standardised conditions to fracture the specimens. Median loads of 3.7 (0.7-6.9) kN led to fractures in the cemented group, whereas cementless fixated tibiae fractured with a median load of 1.6 (0.2-4.3) kN (P = 0.02). The loading capacity in tibiae with cementless components is significantly less compared to cemented fixation. The results show that in case of an extended sagittal bone cut patients especially those with poor bone quality who are treated with a cementless unicompartmental knee arthroplasty are at higher risk for periprosthetic tibial fractures.

Clinical Review of the Zweymuller Femoral Stem

This review summarizes published literature from a range of reputable sources regarding hip prostheses (stems) utilized currently in cementless Total Hip Arthroplasty. The critical review of published clinical studies shows Zweymuller style (Alloclassic and SL-Plus) stems in all critical characteristics.Since the introduction of cementless total hip arthroplasty in the 1970s, a range of design philosophies for femoral and acetabular components have demonstrated variable clinical success1,3. Recently cementless components have been yielding clinical results on par and in some cases even surpassing their cemented predecessors2,4,6. As a result, cementless THA is gaining in popularity1,7. The short-term results of four of the best cementless femoral components recorded in the Norwegian Arthroplasty Register as described by Havelin et al, included the Corail, lMT, Profile and Zweymuller stems with revision for loosening &lt;1% at 4.5 years which was comparable to cemented counterparts.

Total Hip Arthroplasty in Patients with High Dislocation

We report the updated results at a minimum of fifteen years after eighty-four consecutive total hip arthroplasties performed in sixty-seven female patients with high dislocation of the hip. Sixty-four arthroplasties were performed in forty-nine patients, between 1976 and 1994, with Charnley low-friction acetabular and femoral components inserted with cement; nineteen arthroplasties were performed in seventeen patients, between 1990 and 1994, with the hybrid technique (acetabular component inserted without cement and femoral component inserted with cement); and one arthroplasty was done in 1991, with cementless acetabular and femoral components. All patients were followed prospectively on the basis of clinical assessment according to the Merle D'Aubigné and Postel scoring system, as modified by Charnley, and with radiographic analysis. At the time of the latest follow-up, twenty-six hips (41%) in the low-friction arthroplasty series, ten hips (53%) in the hybrid series, and the one hip with the cementless components had been revised for various reasons. The primary reason for revision in the low-friction arthroplasty group was aseptic loosening of the components (twenty-four hips), whereas the predominant reason for the revisions in the hybrid series and in the hip with cementless components was progressive polyethylene liner wear (six hips). After the minimal follow-up of fifteen years, twenty-five low-friction hip replacements and eight hybrid-type hip replacements had remained intact for an average of twenty-one years (range, seventeen to thirty-two years) and sixteen years (range, fifteen to nineteen years), respectively. These findings may be used in comparisons of results with newer techniques and designs.

Hüftgelenkinfektionen – Ergebnisse einer Umfrage unter 28 orthopädischen Universitätskliniken

Despite numerous prophylactic measures infections still remain a hazardous complication in orthopedic surgery. A questionnaire about hip joint infections was sent to all university orthopedic departments in Germany and Austria. The questionnaire included 33 questions with respect to demographic data, causative organisms, diagnostic measures, treatment options for early and late infections, antibiotic therapy and prosthesis reimplantation. The participation rate was 70%. The most frequent primary surgical indication was primary total hip replacement and Staphylococcus aureus and S. epidermidis were the most common pathogens identified. All departments performed a joint aspiration for diagnosis confirmation but for other diagnostic measures a great discrepancy could be observed. In the treatment of early infections removable components were always exchanged, whereas a local antibiotic therapy was not always employed. With regard to late infections a two-stage protocol was more frequently used than a one-stage treatment, whereby the implantation of a cement spacer was more commonly performed than a resection arthroplasty. The time between stages varied between 6 and 12weeks and systemic antibiotics were administered for a mean time of 6 weeks. For prosthesis reimplantion cementless components were mostly used but no clear tendency could be determined for systemic antibiotic therapy. Treatment of hip joint infections among German and Austrian university orthopedic departments is only partly carried out in a similar manner.

Options for Acetabular Component Fixation

Selection of an acetabular component for total hip arthroplasty that can achieve initial stability and then remain stable for long-term fixation to occur requires specific implant design features. In this work, the authors describe the stages of implant fixation for cemented and cementless components, identify the key design characteristics of an acetabular component that will ensure stability as bone remodeling or osseointegration occurs, and review the clinical results of various cup designs. The authors recommend an acetabular component that offers good initial fixation, limits migration during the intermediate stage, provides a mechanism for osseointegration, and resists tensile loads.

Impacted Autograft and Cementless Components in Acetabular Revision: A Retrospective Series

A retrospective review of the short- to medium-term results of acetabular revision using impacted autograft combined with cementless acetabular components is reported. Twenty-five cases with aseptic acetabular loosening and associated bone defects were revised using impacted autograft and a cementless acetabular component. Twenty-five patients were followed for a minimum of 4 years. Mean follow-up was 5.5 years (range 4.0-8.0 years). Radiographs showed that good incorporation of autograft occurred in all cases. Mean Harris hip score improved from 36.0 points (range 20.0 to 50.0) pre-operatively to 85.7 points (range 50.0 to 91.0) at latest follow-up. Outcome was Excellent in 8 cases, Good in 13 cases and Fair in 4 cases. No cases required further revision. The use of impacted autograft in combination with cementless components for acetabular revision can achieve good short- to medium-term result in patients with acetabular bone deficiency.

Cementless Femoral Reconstruction in Patients With Proximal Femoral Deformity

Distorted proximal femoral anatomy can pose a great technical challenge during total hip arthroplasty. Fifty-eight total hip arthroplasty were performed in 51 patients with proximal femoral deformity from 1998 to 2006. All hips except 2 were treated with cementless prosthesis. Twenty-three patients had a retained hardware that had to be removed. Nonprimary cementless components were used in 22 (25%) femurs. In 21 (23%) hips, osteotomy was required to properly fit the cementless stem in the femur. At the time of latest follow-up (4 years on average), functional scores showed significant improvement. Radiographically, all femoral components showed stable bone ingrowth except 2 hips (3.5%) with stable fibrous ingrowth and 1 hip (2%) with loosening. There were 2 (3.5%) revisions in 2 patients for periprosthetic fracture and femoral loosening. The mechanical failure rate was 9% (5 hips). Despite technical difficulties, cementless femoral reconstruction provides a reliable and durable result in patients with proximal femoral deformity.

Custom Cementless THA in Patients with Skeletal Dysplasia Results in Lower Apparent Revision Rates than Other Types of Femoral Fixation

Patients with skeletal dysplasia are prone to degenerative hip disease thus requiring THA at a younger age than the general population. This is a technically demanding procedure with high complication and revision rates. Achieving good femoral fixation can be challenging because of the abnormal features of the hip. We therefore determined: (1) survivorship, (2) function, (3) radiographic findings, and (4) complications associated with a cementless custom-made femoral component used in THAs for patients with skeletal dysplasia and compared these parameters with those from other types of femoral fixation. Between 1992 and 2005, 40 THAs were performed in 25 patients with skeletal dysplasia using custom-made cementless femoral components. There were 15 men and 10 women with a mean age of 37.5 years (range, 18-61 years) and a mean height of 145 cm (range, 120-173 cm). Patients were followed clinically and radiographically for a minimum of 4.3 years (mean, 10.1 years; range, 4.3-18.2 years). The survivorship rates for the femoral and acetabular components were 92% and 70%, respectively, at 220 months. Revision arthroplasty was performed in four of 40 hips (10%). In two, the acetabular component was revised for aseptic loosening, one had both components revised for aseptic loosening, and one had an isolated femoral component revision for deep infection. The mean Harris hip score improved from 41 (range, 27-57) preoperatively to 80 (range, 51-94) at final followup. There were two intraoperative proximal femoral fractures and one dislocation. When compared with studies with equal followup, custom-made cementless components in THAs for patients with skeletal dysplasia apparently had lower revision and complication rates with comparable function and higher midterm survival.

Impaction morselized allografting combined with cementless long stem for femoral defects in femoral component revision

To retrospectively analyze the clinical and radiological results of the impaction morselized allografting combined with cementless long stem for femoral component revision in patients with significant bone loss. From July 2003 to June 2009, 27 patients (27 hips) underwent revision hip arthroplasty in femurs with bone defect using impaction allografting and cementless components. There were 15 male and 12 female with mean age of 67 years. According to the Paprosky classification system, the bone defects in femur were classified into type II in 3 cases, type III in 21 cases and type IV 3 cases. The patients were followed up postoperatively to observe the clinical and radiological results, and if there had the stem subsidence, periprosthetic fracture, infection and other complications. Twenty-three patients were followed up. The mean follow-up time was 26 months. Harris score improved from 43 points pre-revision to 83 points at the final follow-up. No femoral stem loosening and failure occurred. There were 4 stem with a mean 3.3 mm subsidence. One case had an acute infection after revision and treated successfully by debridement and drainage, antibiotics. No stem need further revision. Radiographic analysis showed all the revised stem was stable, and graft incorporation was seen in at least 1 zone in 100% of the femurs. The results of this study demonstrates that femoral support and vigorous impaction grafting combined with cementless long stem results in an good intermediated-term clinical effects.

Fracture of a Modular Femoral Neck After Total Hip Arthroplasty

The use of modularity in femoral stem designs for total hip arthroplasty has increased substantially over the past several years. The theoretical advantages of this design include the optimization of femoral anteversion, limb length, and offset of the femoral component. We report on a previously unreported fracture of a modular femoral neck device. The patient was informed that data concerning the case would be submitted for publication, and he consented. A forty-nine-year-old man underwent a primary total hip arthroplasty of the left hip, in June 2005, because of degenerative osteoarthritis and received a size-4 PROFEMUR Z femoral stem (Wright Medical Technology, Arlington, Tennessee) and a 64-mm CONSERVE acetabular component (Wright Medical Technology). The patient was 6 ft 6 in (198 cm) tall and weighed 340 lb (154.2 kg). An anterolateral surgical approach was utilized, and the bearing surface chosen was metal on metal. This proximal femoral cementless component is a dual-tapered rectangular stem that has a modular neck. The modular neck has an oval taper distally that is inserted into the femoral stem at a fixed angle. This allows the surgeon to independently adjust the offset and length as it is available in six different neck geometries and two lengths. Five different head options, ranging from –3.5 mm to +10.5 mm, are also available with this design. The head and neck are connected by means of a standard 12/14 Morse taper. Both the femoral stem and the modular neck are manufactured from a titanium alloy (Ti-6Al-4V). The patient had a 56-mm head with a –3.5-mm neck length. The neck geometry was a long varus anteverted neck (AR/VV2). The patient was otherwise healthy. The postoperative course was uneventful, and he was pain-free within three months after the procedure. In January 2009 (four years postoperatively), the patient slipped on ice and fell …