Cemented total hip arthroplasty: still relevant in the new millennium?

Total hip arthroplasty can be performed successfully using cement or cementless technology. Cemented femoral stems can achieve enduring long-term suvivorship as long as meticulous surgical technique is utilized and patient selection is appropriate. Cemented acetabular components should only be utilized in patients with less than 10 years of remaining life expectancy. Critical risk factors for cemented total hip arthroplasty include atrophic osteoarthrtis on the acetabular side and unfavorable femoral geometry for the femoral stem such as "the stove-pipe" canal. Rapid polyethylene wear and osteolysis are rarely seen in contemporary cemented total hip arthroplasty performed with a smooth, tapered, collarless femoral stem with a highly polished head and a well-designed acetabular component.     

Mid-term results of Exeter vs Endurance cemented stems

The mid-term results are reported of 2 uniquely different cemented stems implanted and followed prospectively by a single surgeon. The highly polished, collarless, tapered Exeter stem and the Endurance stem, a collared, roughened, satin finished stem, were inserted through a lateral approach using third-generation cement techniques. A total of 118 hips with the Exeter stem with an average follow-up of 7.25 years and 34 hips with the Endurance stem with an average follow-up of 4.57 years are included in the study. The Exeter patients had no revisions for aseptic loosening (0%) of the femoral stem. In contrast, the Endurance patients had 5 revisions and 2 impending revisions for aseptic loosening (20.5%) of the femoral stem with an average time to failure of 3.72 years. The excellent mid-term results of the Exeter stem support its ongoing use. By contrast, because of the poor early results of this modern cemented Endurance stem design, it is no longer used at our institution.     

Total hip reconstruction in the anatomically distorted hip

Recent reports in the literature strongly support the idea that cement is the optimum form of fixation of the femoral component in total hip replacement. For hybrid total hip arthroplasty, we used a cemented cup instead of an uncemented cup since this was inevitable in cases of poorly developed acetabulum. The uncemented cone femoral component is also beneficial in cases of extremely narrow and cylindrical configuration of the medullary cavity of untreated congenital dislocation of the hips (CDH) and tuberculosis or septic arthritis in childhood. We reviewed the clinical result of a consecutive series of patients with cemented total hip arthroplasty (THA) compared with recent studies on hybrid reconstruction using survivorship analysis. This subsequent study involved a hybrid uncemented Wagner cone femoral component and a cemented acetabular component with roof reinforcement by additional impacted cancellous allograft with hydroxyapatite (HA). We believe that early failure of the cemented components was due to an adverse effect of thin cement mantles around cemented femoral stems as well as the cemented cup in THA. In addition, 8 patients who received our modification of the Charnley CDH component had poor results even though we reduced the stem geometry and thickness. Furthermore, intraoperative fracture and splitting of the proximal femur was a major complication during implantation. Contrary to expectations, the results of these hybrid reconstructions were extremely encouraging (average follow-up period of 2–4.5 years). In addition to our experience of the cemented versus hybrid THA involving the uncemented Wagner femoral component, we have determined positive indications for the untreated and severely distorted anatomy of bilateral CDH for which surgical interventions for reconstruction were not recommended before.     

Total hip arthroplasty with a cemented, polished, collared femoral stem and a cementless acetabular component. A follow-up study at a minimum of ten years

BACKGROUND: Recent studies have suggested that cemented femoral components with a polished surface may provide superior long-term fixation when compared with femoral components with a roughened surface. The purpose of this study was to evaluate the results of total hip arthroplasty with a cemented femoral component with a polished surface finish and compare them with the results of total hip arthroplasty performed with a similar design of cemented femoral component with a rougher surface finish. METHODS: We retrospectively reviewed a consecutive group of 132 patients (149 hips) in whom primary total hip arthroplasty had been performed by one surgeon using a cemented collared femoral component with a polished (0.1-microm Ra) surface finish and a cementless acetabular component. Ninety-eight patients (115 hips) were followed for a minimum of ten years. We compared the survivorship of this prosthesis with that of a femoral component of similar design but with rougher surfaces (matte or grit-blasted). RESULTS: No polished stems were revised because of aseptic loosening or demonstrated radiographic evidence of loosening; however, eight hips (5.4%) with a polished stem demonstrated osteolysis distal to the greater or lesser tro-chanter. In contrast, six stems (2.0%) with a matte surface finish of 0.8-microm Ra were revised because of aseptic loosening, and an additional five stems were seen to be loose radiographically. Eleven stems (9.2%) with a grit-blasted surface finish of 2.1-microm Ra were revised because of aseptic loosening, and an additional four stems were seen to be loose radiographically. The difference in the prevalence of revision due to aseptic loosening between the group with the 0.1-microm Ra surface and the group with the 2.1-microm Ra surface was significant (p = 0.001), as was the difference between the prevalence of revision due to aseptic loosening between the group with the 0.8-microm Ra surface and the group with the 2.1-microm Ra surface (p = 0.001). No cups were revised because of aseptic loosening, and one hip had radiographic signs of acetabular loosening. CONCLUSIONS: This study demonstrated excellent durability of a prosthesis consisting of a cemented, collared, polished femoral component and a cementless acetabular component. While no hips were revised because of aseptic loosening, distal femoral osteolysis was observed in eight hips (5.4%), a higher prevalence than has been reported by others after similar durations of follow-up of tapered, collarless, polished femoral components.     

Femoral stem dislodgement during bipolar hemiarthroplasty dislocation

Bipolar hemiarthroplasty remains a treatment option for displaced femoral neck fractures in elderly patients without pre-existing hip disease. Implant-related complications associated with this procedure include acetabular erosion, dislocation, disassembly of the modular components, polyethylene debris-induced osteolysis, metallosis from outer cup impingement, and femoral component loosening. This article presents a case of a patient in whom the polished collarless tapered femoral stem dislodged out of the cement mantle during traumatic bipolar hemiarthroplasty dislocation, 28 days after the index procedure. This complication, associated with bipolar hemiarthroplasty dislocation, was adequately managed by driving the stem back to the original cement mantle, followed by reduction of bipolar component dislocation and placing bone cement over the shoulder of the femoral stem to prevent a new dislodgement episode. Although rare, dislodgement of cemented polished collarless tapered stems from the cement mantle has been recently reported either during dislocation or, more frequently, as a complication of reduction of a dislocated total hip arthroplasty. However, its occurrence in association with bipolar hemiarthroplasty dislocation was not found to have been reported in the literature. The occurrence of femoral stem dislodgement during bipolar hemiarthroplasty dislocation should be considered as a possible complication of such a procedure and may be prevented by routinely placing bone cement over the shoulder of the femoral implant.     

Clinical and radiological results of the collarless polished tapered stem at 15 years follow-up

We prospectively followed 191 consecutive collarless polished tapered (CPT) femoral stems, implanted in 175 patients who had a mean age at operation of 64.5 years (21 to 85). At a mean follow-up of 15.9 years (14 to 17.5), 86 patients (95 hips) were still alive. The fate of all original stems is known. The 16-year survivorship with re-operation for any reason was 80.7% (95% confidence interval 72 to 89.4). There was no loss to follow-up, with clinical data available on all 95 hips and radiological assessment performed on 90 hips (95%). At latest follow-up, the mean Harris hip score was 78 (28 to 100) and the mean Oxford hip score was 36 (15 to 48). Stems subsided within the cement mantle, with a mean subsidence of 2.1 mm (0.4 to 19.2). Among the original cohort, only one stem (0.5%) has been revised due to aseptic loosening. In total seven stems were revised for any cause, of which four revisions were required for infection following revision of the acetabular component. A total of 21?patients (11%) required some sort of revision procedure; all except three of these resulted from failure of the acetabular component. Cemented acetabular components had a significantly lower revision burden (three hips, 2.7%) than Harris Galante uncemented components (17 hips, 21.8%) (p < 0.001). The CPT stem continues to provide excellent radiological and clinical outcomes at 15?years following implantation. Its results are consistent with other polished tapered stem designs.     

Normalized and proportionalized cemented femoral stem survivorship at 15 years.

We reviewed the clinical and radiographic results of a series of 215 consecutive hip arthroplasties in which a normalized, proportionalized, cemented femoral component was implanted. This component design may encourage more efficient force transmission from prosthesis to cement to bone and lessen hoop stresses and resultant interface failure. A total of 127 hips in 103 patients with a follow-up of 13 to 17 years (average, 14.8 years) were available for evaluation, which included survivorship analysis. An aseptic failure loosening rate of 3.9% at 15 years for this stem favorably compares with other reported series of first-generation and second-generation stems at similar follow-up. Excluding the 8 stems placed in varus, of which 3 required revision (failure rate, 37.5%), the series has a failure rate of 1.6%.     

Minimum 30-Year Results of Bilaterally Implanted Cemented and Cementless Total Hip Arthroplasty in Patients Younger Than 50 Years

BackgroundThe rate of failure of cemented and cementless total hip arthroplasty (THA) in younger patients is higher than that in elderly patients. The purpose of this study is to document the long-term clinical results of THA with the so-called third-generation cementing and the results of second-generation cementless THA in patients <50 years of age.MethodsThis study included 106 patients who had had bilateral THA with a cemented stem in one hip and a cementless stem in the other. There were 78 men and 28 women. Their mean age was 47 years (range, 21-49). The average follow-up duration was 31 years (range, 30-32.5).ResultsThere were similar mean Harris Hip Scores (90 versus 91 points) between the groups at the final follow-up. Forty-six acetabular components (43%) in the cemented group and 48 acetabular components (45%) in the cementless group were revised. Five femoral components (5%) in the cemented group and 4 femoral components (4%) in the cementless group were revised. Survivorship of the acetabular component at 30.8 years was similar in both groups (57% in the cemented group versus 55% in the cementless group). Survivorship of the femoral component at 30.8 years was also similar in both groups (95% in the cemented group versus 96% in the cementless group).ConclusionLong-term fixation of the cemented or cementless femoral stem was outstanding. There was a high rate of the acetabular component revision due to conventional polyethylene wear and periacetabular osteolysis in both hybrid and fully cementless THA groups.     

Cement Mantle Quality and Stem Alignment in Cemented Collarless Polished Tapered Stems Implanted via the Direct Anterior and Direct Lateral Approaches: A Single Institution Experience

BackgroundThe aim of this study was to compare the stem alignment and the quality of cement mantle of collarless polished tapered cemented stems inserted through the direct anterior approach (DAA) and the direct lateral approach (DLA).MethodsA comparative retrospective study of 232 hybrid total hip arthroplasties using a cemented collarless polished tapered stem through either the DAA (n = 147) or DLA (n = 85) was performed. Radiographic evaluation included stem alignment, cement mantle quality, and cement mantle thickness.ResultsOn anteroposterior radiographs, stems implanted through the DLA were more likely to be in neutral alignment, than those implanted through the DAA (83.5%[n = 71] versus 71.4% [n = 105]; P = <.001). No difference between approaches was noted for stem alignment on lateral radiographs or cement mantle quality. Multivariate analysis revealed factors associated with suboptimal cement mantle and included Dorr type B or C femur as well as male gender. A mean cement mantle thickness ≥2mm was achieved in all Gruen zones for both approaches.ConclusionIn our series, the DAA was associated with a higher incidence of coronal plane stem malalignment compared to the DLA when using cemented tapered polished femoral components for total hip arthroplasty. No difference in lateral stem alignment or cement mantle quality was found.     

Durability of the cemented femoral stem in patients 60 to 80 years old

The importance of surface roughness and durability of fixation of the cemented femoral stem were examined. Three cohorts of patients approximately 60 to 80 years old, had cemented total hip replacements: Charnley (1978-1983) with first-generation cement technique consisting of canal-plugging and digital packing; Omnifit (1986-1991), and Ranawat-Burstein (R-B) Interlok (1992-1994) with modified third-generation cement technique. Kaplan-Meier survivorships, using failure for all causes (best case) were 90% +/- 5.1% at 20 years for the Charnley 95.1%+/- 3.4% at 15 years for the Omnifit and 99.5% +/- 0.5% at 9 years for the R-B Interlok prosthesis. Log rank test with paired data showed no significant differences between the groups for mechanical failure as an end point. Comparisons of survivorship curves for failure from all causes showed significant differences between the Charnley compared with the Omnifit and Interlok series respectively, with no significant differences between the Omnifit and R-B Interlok series. The cemented femoral stem, with a good cement mantle and surface roughness ranging from 30 to 150 microinches, did not show any significant differences in mechanical failure. Other variables such as stem centralization and low polyethylene wear need additional evaluation in survivorship of cemented total hip replacements.     

The Exeter Universal stem: a minimum ten-year review from an independent centre

We reviewed 142 consecutive primary total hip replacements implanted into 123 patients between 1988 and 1993 using the Exeter Universal femoral stem. A total of 74 patients (88 hips) had survived for ten years or more and were reviewed at a mean of 12.7 years (10 to 17). There was no loss to follow-up. The rate of revision of the femoral component for aseptic loosening and osteolysis was 1.1% (1 stem), that for revision for any cause was 2.2% (2 stems), and for re-operation for any cause was 21.6% (19 hips). Re-operation was because of failure of the acetabular component in all but two hips. All but one femoral component subsided within the cement mantle to a mean of 1.52 mm (0 to 8.3) at the final follow-up. One further stem had subsided excessively (8 mm) and had lucent lines at the cement-stem and cement-bone interfaces. This was classified as a radiological failure and is awaiting revision. One stem was revised for deep infection and one for excessive peri-articular osteolysis. Defects of the cement mantle (Barrack grade C and D) were found in 28% of stems (25 hips), associated with increased subsidence (p = 0.01), but were not associated with endosteal lysis or failure. Peri-articular osteolysis was significantly related to the degree of polyethylene wear (p < 0.001), which was in turn associated with a younger age (p = 0.01) and male gender (p < 0.001). The use of the Exeter metal-backed acetabular component was a notable failure with 12 of 32 hips (37.5%) revised for loosening. The Harris-Galante components failed with excessive wear, osteolysis and dislocation with 15% revised (5 of 33 hips). Only one of 23 hips with a cemented Elite component (4%) was revised for loosening and osteolysis. Our findings show that the Exeter Universal stem implanted outside the originating centre has excellent medium-term results.     

The effect of a collar and surface finish on cemented femoral stems: a prospective randomised trial of four stem designs

Purpose

The optimal design for a cemented femoral stem remains a matter of debate. Over time, the shape, surface finish and collar have all been modified in various ways. A clear consensus has not yet emerged regarding the relative merits of even the most basic design features of the stem. We undertook a prospective randomised trial comparing surface finish and the effect of a collar on cemented femoral component subsidence, survivorship and clinical function.

Methods

One hundred and sixty three primary total hip replacement patients were recruited prospectively and randomised to one of four groups to receive a cemented femoral stem with either a matt or polished finish, and with or without a collar.

Results

At two years, although there was a trend for increased subsidence in the matt collarless group, this was not statistically significant (p = 0.18). At a mean of 10.1 years follow-up, WOMAC scores for the surviving implants were good, (Range of means 89–93) without significant differences. Using revision or radiographic loosening as the endpoint, survivorship of the entire cohort was 93 % at 11 yrs, (CI 87–97 %). There were no significant differences in survivorship between the two groups with polished stems or the two groups with matt stems. A comparison of the two collarless stems demonstrated a statistically significant difference in survivorship between polished (100 %) and matt (88 %) finishes (p = 0.02).

Conclusions

In the presence of a collar, surface finish did not significantly affect survivorship or function. Between the two collarless groups a polished surface conferred an improved survivorship.     

Contemporary total hip arthroplasty with and without cement in patients with osteonecrosis of the femoral head: a concise follow-up, at an average of seventeen years, of a previous report

We previously evaluated ninety-eight consecutive patients (148 hips) at mean of 9.3 years after total hip arthroplasty; the mean age at the time of the index surgical procedure was 47.3 years. Fifty patients (100 hips) had simultaneous bilateral arthroplasty with a cemented stem in one hip and a cementless stem in the contralateral hip. Forty-eight patients (forty-eight hips) had unilateral hip arthroplasty with a cementless stem. All patients had a cementless acetabular component. In our first report, we found no difference in clinical results, as measured with the Harris hip score and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), between the cementless and cemented stems. One hip (2%) in the hybrid group (a cementless cup and a cemented stem) had revision because of infection and two hips (2%) in the fully cementless group had revision of the femoral component because of a periprosthetic fracture. Between the time of follow-up in that study (at a mean of 9.3 years) and the time of follow-up in the present study (at a mean of 17.3 years), twenty-two revisions of acetabular components were performed, with eight in the hybrid group and fourteen in the fully cementless group. There was no difference in clinical results, as measured with the Harris hip score and the WOMAC, between the hybrid and fully cementless groups. At the time of the present review, forty (83%) of forty-eight acetabular components in the hybrid group and eighty (85%) of ninety-four acetabular components in the fully cementless group were intact. Most of the femoral components (98%) in both groups were intact. Wear and periacetabular osteolysis were the causes of failure in the hips requiring revision.     

Analysis of cement mantles in collared versus collarless femoral components

The purpose of this study was to compare the cement mantles of 100 consecutive collared cemented stems with those of 100 consecutive collarless cemented stems of similar design. All stems were implanted by the same surgeon. Two independent examiners retrospectively reviewed the results. Between the 2 femoral stem types, there was no statistical difference in proximal medial cement mantle size, stem orientation, canal-fill percentage, or cement mantle grade, and there was no radiographic difference in cement mantle quality or stem position.     

Results of cemented metal-backed acetabular components: A 10-year-average follow-up study

The clinical and radiographic results of 86 primary total hip arthroplasties performed in 74 patients from 1983 to 1987 with a cemented metal-backed acetabular component and a cemented collared straight femoral stem with a 32-mm head were reviewed at a mean follow-up of 10.1 years. Seven patients (9.2%) underwent acetabular component revision at a mean of 9.0 years after implantation; an additional 24 components (31.6%) demonstrated evidence of radiographic loosening, resulting in a total failure rate of 40.8%. Periacetabular radiolucencies were noted in Charnley zones at the following rates: 34.2% in zone I, 18.4% in zone II, and 27.6% in zone III. In addition, 18.4% and 38.2% of implants demonstrated evidence of migration and excessive polyethylene wear. Excessively vertical cup placement (>49° inclination) at the time of initial arthroplasty was statistically correlated with polyethylene wear, implant migration, and fixation failure. A trend of increasing implant failure was also noted with decreasing polyethylene liner thickness. Periacetabular cement mantle thickness was not statistically correlated with subsequent component loosening or failure. Results of Kaplan-Meier survivorship analysis using revision as an endpoint showed 93.6% survivorship at 10 years and 88.4% at 12 years. The mean modified Harris hip scores were 46.9 preoperatively and 81.8 at final follow-up. The significant overall rates of radiographic loosening, migration, polyethylene wear, and implant revision confirm the suspected trend of increasing failure rates of cemented metal-backed acetabular components over time.     

Comparison between straight- and curved-stem Müller femoral prostheses. 5- to 10-year results of 545 total hip replacements

Between 1977 and 1982, 545 cemented femoral prostheses were implanted, in combination with a noncoated cementless polyethylene acetabular component (RM cup). Three hundred and eighty-one straight-stem and 76 curved-stem Müller femoral components were implanted, as well as 88 collared components with a 130-mm stem and a 130 degrees neck-shaft angle, derived from a long-stem steel prosthesis. Survivorship analysis of revisions for aseptic loosening at 10 years revealed 97% straight-stem survival, 91.6% curved-stem survival, and 88.3% 130 degrees stem survival. "Survival" curves were also constructed for radiological loosening, and the survival rates (patients without radiological evidence of loosening) were 69.8%, 78.8%, and 63.1% respectively at 10 years. The 130 degrees collared stem was associated with significantly less acetabular loosening than the other prostheses. This resulted in less calcar resorption, but there was a higher rate of stem loosening. Acetabular loosening and associated wear products appear to be responsible for calcar resorption, and stress shielding of the calcar appears to be of minor importance in the pathogenesis of aseptic stem loosening. Better cementing techniques have improved survivorship of the curved-stem prosthesis, and early fears of high rates of radiological loosening with the straight stem have not been substantiated.     

Clinical outcome of total hip arthroplasty using the normalized and proportionalized femoral stem with a minimum 20-year follow-up

Currently, there are several femoral stem designs available for use, but few have an extended track record. We have previously reported on 10- and 15-year outcome studies of total hip arthroplasty (THA) using a cemented normalized and proportionalized femoral stem from a single surgeon series. This is a follow-up study reporting the minimum 20-year outcome of this femoral stem design. The study began with THA performed in a consecutive series of 184 patients; stem fixation was achieved using first-generation cementing techniques. The overall early complication rate was 10%. There were 23 patients (31 hips) who had been followed-up for a minimum 20-year period (average 21.3 years). Mean d'Aubigne and Postel scores improved from 5.9 to 11.3; mean Harris hip scores improved from 43.8 to 92.8. Kaplan-Meier survivorship was 93% at 20 years (95% confidence interval); there were no stem failures. The use of a cemented normalized and proportionalized femoral stem in primary THA provides satisfactory long-term clinical and radiological outcomes in patients.     

Comparison between straight- and curved-stem Müller femoral prostheses

Summary Between 1977 and 1982, 545 cemented femoral prostheses were implanted, in combination with a noncoated cementless polyethylene acetabular component (RM cup). Three hundred and eighty-one straight-stem and 76 curved-stem Miller femoral components were implanted, as well as 88 collared components with a 130-mm stem and a 130° neck-shaft angle, derived from a long-stem steel prosthesis. Survivorship analysis of revisions for aseptic loosening at 10 years revealed 97% straight-stem survival, 91.6% curved-stem survival, and 88.3% 130° stem survival. Survival curves were also constructed for radiological loosening, and the survival rates (patients without radiological evidence of loosening) were 69.8%, 78.8%, and 63.1% respectively at 10 years. The 130° collared stem was associated with significantly less acetabular loosening than the other prostheses. This resulted in less calcar resorption, but there was a higher rate of stem loosening. Acetabular loosening and associated wear products appear to be responsible for calcar resorption, and stress shielding of the calcar appears to be of minor importance in the pathogenesis of aseptic stem loosening. Better cementing techniques have improved survivorship of the curved-stem prosthesis, and early fears of high rates of radiological loosening with the straight stem have not been substantiated.     

High failure rate of a modern, proximally roughened, cemented stem for total hip arthroplasty

The role of surface finish on the survivorship of cemented femoral stems continues to be debated. A total of 34 proximally roughened cemented stems were implanted in 33 consecutive patients undergoing total hip arthroplasty by a single surgeon. An alarmingly high failure rate was observed, prompting a retrospective chart review, analysis of radiographs, and evaluation of retrieved stems and pathological specimens. Nineteen patients were available with more than two years follow-up. Of these 19 patients, nine stems had failed (47%) due to severe osteolysis and stem loosening. Failures were significantly more common in the male gender (p<0.005), and young (p=0.05), tall (p<0.002), and heavy patients (p<0.004). All failed revised hips showed severe metallosis, with both gross and microscopic evidence of metallic shedding from the stems. Our findings suggest that this proximally roughened stem is susceptible to early failure. Failure is characterized by stem debonding, subsidence within the cement mantle, shedding of metallic and cement particles due to fretting, and rapidly progressive osteolysis. These findings have been observed with other rough surface finish cemented stems.     

Cemented collarless (exeter-CPT) versus cementless collarless (PCA) femoral components: A 2- to 14-year follow-up evaluation

The purpose of this study was to compare the intermediate results of total hip arthroplasty with a cemented, collarless, femoral prosthesis design (Exeter, Howmedica, Middlesex, UK and CPT, Zimmer, Warsaw, IN) with those of a cementless, collarless, porous-coated femoral component (PCA, Howmedica). A total of 151 hips in 128 patients were reviewed. In the cemented group, 85 Exeter-CPT prostheses were used in 71 patients with an average follow-up period of 6.5 years. In the uncemented group, 66 PCA prostheses were placed in 57 patients with an average follow-up period of 7 years. Harrington hip scores improved from 50.1 to 80.7 for the PGA group and from 49.5 to 87.3 for the Exeter-CPT group. The patient satisfaction rates were 89 and 96%, respectively. Sixty-eight patients with Exeter or CPT prostheses had excellent function and no significant thigh pain after 2 years. One Exeter stem was revised 10 years after the primary surgery because of localized osteolysis due to cement defect. Two Exeter sockets were revised because of aseptic loosening. In the PCA group, the incidence of thigh pain that persisted beyond 2 years was 39.4%, and there were high incidences of distal cortical hypertrophy (66.6%) and bead loosening (45.5%). Sixteen hips were revised for aseptic stem loosening, uncontrollable thight pain, or stem fracture (1 hip), and seven were revised because of migration and aseptic loosening of the socket. The cementless ingrowth stems failed earlier (around 5 years), whereas the cemented stems continued to perform well past 14 years. In this study, the cemented, collarless, collarless, porous-coated anatomic design at an average follow-up period of 7 years (range, 2–14 years).