Modern Revision Femoral Stem Designs Have No Difference in Rates of Subsidence

BackgroundBoth modular and monoblock tapered fluted titanium (TFT) stems have gained popularity over fully porous-coated cylindrical (FPCC) femoral stem designs, but limited data exist comparing subsidence rates following revision total hip arthroplasty (THA). The purpose of this study is to determine differences in subsidence and clinical outcomes among 3 revision femoral stem designs.MethodsWe reviewed a consecutive series of 335 patients who underwent femoral component revision to a cementless modular TFT (n = 225), monoblock TFT (n = 63), or FPCC (n = 47) stem between 2012 and 2019. We evaluated radiographic subsidence rates, re-revision rates, and patient-reported outcomes between the 3 stems. A multivariate regression analysis was performed to determine the independent effect of stem type on the risk of subsidence >5 mm.ResultsAt an average follow-up of 39 months (range, 12 to 96 months), there were no differences in mean subsidence rates (3.5 vs 2.4 vs 2.1 mm, P = .14), HOOS Jr scores (78 vs 74 vs 64 points, P = .15), or aseptic re-revision rates (4% vs 3% vs 0%, P = .29) between modular TFT, monoblock TFT, and FPCC stems. Although modular TFT stems were more often used in patients with extensive femoral bone loss (Paprosky III and IV), there were no differences in subsidence rates >5 mm among the 3 stems (P > .05) in multivariate analysis.ConclusionModular TFT, monoblock TFT, and FPCC femoral stem designs all perform well in revision THA with no difference in clinical outcomes or subsidence rates. Surgeons should select the stem which they feel is the most clinically appropriate.     

A Role for Modern Primary Cementless Femoral Stems in Revision Hip Arthroplasty

BackgroundIn revision total hip arthroplasty (THA) cases with preserved femoral metaphyseal bone, tapered proximally porous-coated “primary” femoral stems may be an option. The objective of this study was to compare outcomes of patients with Paprosky I or II femoral bone loss undergoing revision THA with either a primary metaphyseal-engaging cementless stem or a revision diaphyseal-engaging stem.MethodsThis was a retrospective analysis of 70 patients with Paprosky I or II femoral bone loss who underwent femoral revision. 35 patients who were revised using a primary cementless femoral stem were compared with 35 patients who underwent femoral revision using a revision diaphyseal-engaging stem. The groups were similar regarding age, gender, body mass index, and American Society of Anesthesiologists. Clinical and radiographic outcomes and complications were compared over an average follow-up of 2.9 years (SD 1.4).ResultsRevision THA was most commonly performed for periprosthetic joint infection (N = 27, 38.6%). The groups were similar with regards to Paprosky femoral classification (P = .56), length of stay (P = .68), discharge disposition (P = .461), operative time (P = .20), and complications (P = .164). There were no significant differences between primary and revision femoral stem subsidence (0.12 vs. 0.75 mm, P = .18), leg length discrepancy (2.3 vs. 4.05 mm, P = .37), and Hip Disability and Osteoarthritis Outcome Score Jr (73.1 [SD 21.1] vs. 62.8 [SD 21.7], P = .088). No patient underwent additional revision surgery involving the femoral component.ConclusionUse of modern primary cementless femoral stems is a viable option for revision hip arthroplasty in the setting of preserved proximal femoral metaphyseal bone. Outcomes are not inferior to those of revision stems and offer potential benefits.     

A Systematic Review and Meta-Analysis of Non-database Comparative Studies on Cemented Versus Uncemented Femoral Stems in Primary Elective Total Hip Arthroplasty

BackgroundCemented and uncemented femoral stems have shown excellent survivorship and outcomes in primary total hip arthroplasty (THA). Cementless stems have become increasingly common in the United States; however, multiple large database studies have suggested that elderly patients may have fewer complications with a cemented stem. As conclusions from large databases may be limited due to variations in data collection, this study investigated femoral stem survivorship and complication rates based on cement status in non-database studies.MethodsPreferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were utilized to identify articles for inclusion up until June 2021. Included articles directly compared outcomes and complications between patients undergoing primary THA without femoral stem cementing to those with cementing. Studies were excluded if they utilized large databases or consisted of patients with a preoperative diagnosis of trauma.ResultsOf the 1700 studies, 309 were selected for abstract review and nineteen for full-text review. A total of seven studies were selected. Meta-analyses indicated substantial heterogeneity between studies. There were no differences in revision rates (cementless: 5.53% vs. cemented 8.91%, P = .543), infection rates (cementless: 0.60% vs. cemented: 0.90%, P = .692), or periprosthetic fracture rates (cementless: 0.52% vs. cemented: 0.51%, P = .973) between groups.ConclusionThere is scarce literature comparing outcomes and complications between cemented and cementless femoral stems in primary elective THA without utilizing a database methodology. In our study, there were no differences in complications detected on meta-analyses. Given previous findings in database studies, additional high-quality cohort studies are required to determine if selected patients may benefit from a cemented femoral stem.     

Bicortical Contact Predicts Subsidence of Modular Tapered Stems in Revision Total Hip Arthroplasty

BackgroundWe describe the intraoperative parameters that affect stem subsidence rates in tapered modular femoral stems for revision total hip arthroplasty (THA). We also determine the effect of the stem bicortical contact on subsidence rates and whether there is a minimum threshold bicortical contact that must be achieved to avoid the complication of subsidence.MethodsThis is a retrospective cohort study consisting of 109 hips in 105 patients (53 males and 52 females) at a minimum of 2 years of follow-up. All revisions were carried out for Paprosky type 3A and 3B femoral deficits. Clinical outcomes included the indication for revision, aseptic re-revision surgery, specifications of the stem inserted, and specifications of the femoral head and acetabular components implanted. Radiographic outcome measures included subsidence (mm) and bicortical contact (mm).ResultsUsing multivariate regression analysis, 3 parameters were associated with an increased rate of stem subsidence. A reduced bicortical contact distance (P < .001) and a stem length of ≤155 mm (P < .001) were both associated with higher subsidence rates. We also demonstrated a novel threshold of 20-mm bicortical contact which must be achieved to significantly reduce subsidence rates in these modular femoral stems for revision THA.ConclusionSubsidence rates of modular tapered femoral stems for revision THA can be significantly reduced by increasing the initial bicortical contact of the stem within the diaphysis and the overall length of the femoral stem >155 mm. We describe a minimum threshold bicortical contact distance of 20 mm that should ideally be exceeded to significantly reduce the risk of stem subsidence within the femoral canal.     

Femoral Stem Survivorship in Dorr Type A Femurs After Total Hip Arthroplasty Using a Cementless Tapered Wedge Stem: A Matched Comparative Study With Type B Femurs

Background

There is a lack of understanding on relationship between the femoral geometry and outcomes of total hip arthroplasty (THA). We investigated clinical and radiographic outcomes of THA using a cementless tapered wedge stem in patients with Dorr type A proximal femoral morphology and compared with those of type B femurs at a minimum follow-up of 5 years.

Novel measurement method on plain radiographs to predict postoperative stem anteversion in cementless THA

Preoperative knowledge of femoral stem anteversion can reduce instability and impingement especially using the standard “cup first” technique in cementless total hip arthroplasty (THA). In this study, we asked whether stems at risk of retroversion or high anteversion (>20°) can be detected preoperatively using hip radiographs in two planes (anteroposterior and Lauenstein). In 123 patients undergoing cementless THA using a non‐anatomic, non‐modular, straight stem, low centered hip radiographs in two planes were obtained preoperatively and three‐dimensional computed tomography (3D‐CT) 6 week postoperatively. The novel developed Isthmus Ratio (iRatio) as the relation between canal isthmus and calcar isthmus in the anteroposterior and Lauenstein view was calculated by two observers twice in a 6‐week interval. iRatio was compared to postoperative 3D‐CT stem version measured by an independent and blinded, external institute. We found a correlation between mean radiographic iRatio and 3D‐CT stem torsion of r = 0.578 (p < 0.0001). The observers had excellent agreements within (ICC ≥0.918) and between (mean CCC = 0.967) radiographic iRatio measurements. Eighty‐one percent (21/26) of the retroverted cementless stems had a preoperative iRatio below 0.35 and 91% (10/11) of stems with an anteversion exceeding 20° an iRatio above 0.55, respectively. The novel iRatio represents a feasible and reliable method for analyzing anteversion of the final stem on plain radiographs before cementless THA with a straight, tapered stem. iRatios below 0.35 and above 0.55 represent a warning of retroversion and anteversion more than 20° of the final stem, respectively. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2025–2030, 2016.     

Cortical Strut Allograft Support of Modular Femoral Junctions During Revision Total Hip Arthroplasty

Background

There is risk of junction failure when using modular femoral stems for revision total hip arthroplasty (THA), especially with loss of bone stock in the proximal femur. Using a cortical strut allograft may provide additional support of a modular femoral construct in revision THA.

Conical Primary Cementless Stem in Revision Hip Arthroplasty: 94 Consecutive Implantations at a Mean Follow-Up of 12.7 years

BackgroundRevision of a failed total hip arthroplasty (THA) poses technical challenges. The use of primary stems for revision can be advantageous for maintaining bone stock and reducing complications: small case series have reported promising results in the short-term to mid-term follow-up. The aim of this study was to evaluate the long-term clinical and functional results and survivorship of a consecutive series of THA femoral component revisions using a conical primary cementless stem (PCS).MethodsNinety-four stem revisions with a preoperative Paprosky I or II defect were analyzed at an average follow-up of 12.7 ± 5.4 years. Aseptic loosening was the reason for revision in 92.5% of cases. Twenty patients were lost to follow-up. Two subgroups were created: Group 1 (n = 59) underwent isolated stem revision; Group 2 (n = 15) underwent complete THA revision. All were evaluated preoperatively and postoperatively based on the Harris Hip Score (HHS), the Western Ontario and McMaster Universities Index (WOMAC) score, and the visual analog scale for pain (VAS). Residual trochanteric pain and length discrepancies were recorded. Radiographic evaluation included signs of osteolysis, subsidence, loosening, and heterotopic ossification.ResultsPCS survivorship was 100% at 5 years and 95.9% at 10 years. Overall, significant postoperative improvements (P < .01) were observed on the HHS (44.3 vs 86.9), WOMAC (42.8 vs 82.8), and VAS (7.0 vs 3.0). Postoperative scores on all scales were higher for Group 1 (P < .01). Three patients (4.1%) underwent further stem revision. Demarcation lines (1 mm) were found in 12 (16.2%) patients and significant heterotopic ossifications in 22 (29.7%).ConclusionThe use of PCS for stem revision in failed THA with a limited femoral bone defect is a reliable option for both isolated stem revision and concomitant cup revision in well-selected patients.     

Periprosthetic Femoral Fractures in Cementless Short Versus Straight Stem Total Hip Arthroplasty: A Propensity Score Matched Analysis

BackgroundRecent studies indicate a decreased risk of periprosthetic femoral fractures (PFFs) in cementless total hip arthroplasty (THA) for short compared to straight stems. However, the results are still inconclusive. Therefore, we retrospectively investigated the rate of PFFs within the first year between cementless short and straight stem THA.MethodsA 1:1 propensity score matching of 3,053 THAs was performed. Two groups including 1,147 short stem THAs implanted through a minimally invasive antero-lateral approach and 1,147 straight stem THAs implanted through a transgluteal Hardinge approach were matched. The rates of PFFs and fracture patterns were compared between both stem types. Risk factors for PFFs were analyzed by multivariate regression analyses.ResultsThe overall rate of PFFs was 1.7% in short stem THA and 3.2% in straight stem THA (P = .015). Postoperatively detected Vancouver A fractures occurred significantly more often in straight stem THA (P = .002), while the occurrence Vancouver B fractures did not differ significantly (P = .563). The risk of PFFs was significantly increased for women in straight stem THA (Odds ratio (OR) 2.620; Confidence Interval (CI) 1.172-5.856; P = .019). Increasing age showed a significantly increased odds ratio in short stem (OR 1.103; CI 1.041-1.169, P < .001) and straight stem THA (OR 1.057; CI 1.014-1.101, P = .008).ConclusionShort stem THA reduces Vancouver Type A PFFs in the trochanteric region compared to straight stem THA, while Vancouver Type B fractures are comparable. Increasing age is a significant risk factor for both stem types, while the risk for PFFs in women was only significantly increased in the straight stem group.     

Midterm Outcomes and Frequency of Osteolysis of Total Hip Arthroplasty Using Cementless Modular Stem for Asian Patients

BackgroundModular stems are useful for total hip arthroplasty (THA) in anatomically difficult dysplasia. Here, we present mean 6.8-year outcomes of cementless primary THA using S-ROM-A (modified modular stem for Asian patients) femoral prosthesis in anatomically difficult cases.MethodsCharts of 373 patients (461 hips) undergoing THA (mean age, 58 years) were reviewed for clinical evaluation of modified Merle d’Aubigné-Postel score and Kaplan-Meier survivorship with revision for any reason as the end point. For radiographic analysis, 331 patients (412 hips) followed up for ≥5 years were included. Bearing couples were metal-on-metal (n = 145), metal-on-polyethylene (n = 120), and ceramic-on-polyethylene (n = 147). Radiography and multiplanar computed tomography were performed.ResultsNo postoperative dislocation or deep infection occurred. Mean modified Merle d’Aubigné-Postel score improved significantly (10.9 points preoperatively, 16.7 points at last follow-up; P < .001). Cumulative 5- and 10-year stem survival rates were 100% and 84%, respectively (95% confidence interval, 75%-93%). All stems were classified as bone ingrown fixation. Osteolysis occurred in metal-on-metal (42.8%) and metal-on-polyethylene (15.8%) groups. Mean time to osteolysis was ~3 years, with no significant difference between 3 groups (P = .264). In logistic regression, lower cup inclination angle was significantly associated with osteolysis (odds ratio, 0.914; 95% confidence interval, 0.84-0.99; P = .029).ConclusionS-ROM-A femoral prosthesis achieved excellent midterm fixation, and the modular system was useful in primary THA with severe deformity. Bearing couples are potentially associated with adverse reactions to metal debris. S-ROM-A with ceramic-on-polyethylene bearing couples may be an option for anatomically difficult THA.     

Long-Term Results of Revision Total Hip Arthroplasty Using a Modern Extensively Porous-Coated Femoral Stem

BackgroundThe use of an extensively porous-coated uncemented cobalt-chrome monoblock femoral stem for revision total hip arthroplasty (THA) is well established with excellent mid-term results. The aim of this study is to report the long-term survivorship of these implants in femoral stem revisions.MethodsThis is a long-term retrospective review of prospectively collected data of 55 femoral stem revisions in 55 patients using a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem. All patients between 2001 and 2006 who underwent first time femoral stem revision with a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem were included. Harris Hip Score, Western Ontario and McMaster Universities Index, and University of California Los Angeles activity scores were recorded preoperatively and at latest follow-up. Radiographs were analyzed for evidence of loosening, subsidence, osteolysis, and bony union. This study included 55 patients, comprising of 36 females (66%) and 19 males (34%) with a mean age of 66.4 ± 9.3 years at the time of surgery. The mean time interval from index procedure was 9.8 ± 2.9 years. Mean time from revision THA to final follow-up was 13.2 ± 2.17 years with a minimum of 10 years of follow-up.ResultsIndications for revision included aseptic loosening (33), prosthetic joint infection (13), and periprosthetic fracture (10). Significant improvement in Harris Hip Score (85.1 ± 1.77 vs 51.8 ± 2.3, P < .001), Western Ontario and McMaster Universities Index (17.6 ± 0.77 vs 33.3 ± 0.8, P < .001), and University of California Los Angeles (5.25 ± 0.2 vs 2.7 ± 0.36, P < .001) scores were found at latest follow-up compared to preoperative. Fifty-four patients (98%) achieved stable bony ingrowth on radiographic analysis. All 10 patients treated for periprosthetic fractures achieved bony union of their fractures. Two patients suffered intraoperative periprosthetic fractures and were treated with a cable-plating system. There were no mechanical failures and no femoral stem re-revisions. One patient was diagnosed with a deep infection and was treated with chronic suppressive antibiotic therapy due to significant medical comorbidities.ConclusionRevision of the femoral component with a contemporary extensively porous-coated cobalt-chrome femoral stem has excellent functional outcomes, radiographic outcomes, and long-term survivorship with minimal complications.     

Long-Term Outcomes of Revision Total Hip Arthroplasty Using a Tapered and Fluted Modular Stem: A Mean Follow-Up of 16 Years

BackgroundTapered modular stems are increasingly used in revision total hip arthroplasty (THA) with deficient femoral bone stock. This study aimed to report the long-term outcomes of revision THA using a tapered and fluted modular stem.MethodsBetween December 1998 and February 2006, 113 revision THAs (110 patients) were performed with a tapered and fluted modular stem at a single institution. Hip radiographs were used to identify stem subsidence, stability, and femoral radiolucency. Final outcomes were assessed in 72 hips (70 patients), with a minimum follow-up of 10 years.ResultsThe mean follow-up duration was 16 years (range, 10-23). At the final evaluation, the Harris Hip Score improved from a mean of 41 points (range, 10-72) preoperatively to 83 points (range, 56-100) (P < .001). Six femoral re-revisions were performed for the following reasons: 1 aseptic loosening, 2 stem fractures, and 3 infections. One stem fracture occurred at the modular junction after 14 years, and the other at a more distal location after 15 years. Stem subsidence was >5 mm in 6 hips (9.1%), but secondary stability was achieved in all stems. Osseointegration was observed in 63 (95.5%) hips. Stem survivorship was 91.1% with an end point of any re-revision and 94.6% for aseptic re-revision.ConclusionA tapered and fluted modular stem demonstrated excellent implant survivorship with reliable bony fixation at a mean follow-up of 16 years. This type of stem can be a durable option for revision THA in patients who have femoral defects.     

Cemented Polished Tapered Stems Have Lower Revision Rates Than Commonly Used Cementless Implant up to 17 Years of Follow-Up: An Analysis of 201,889 Total Hip Replacements From the Australian Orthopedic Association National Joint Replacement Registry

BackgroundData assessing femoral stems may be influenced by grouping together matt and polished stems, despite their differing reported survivorship. The aim of this study is to assess the difference in revision rates between commonly used cemented and cementless stems when polished tapered stems are assessed independently of matt stems.MethodsAustralian Orthopaedic Association National Joint Replacement Registry data from 1999 to 2019 were used to assess difference in revision rates between the 5 most commonly implanted femoral cemented and cementless stems for osteoarthritis. Cemented matt femoral stems, stems using line-to-line cementing techniques and procedures using non-cross-linked polyethylene, large head (>32 mm) metal-on-metal bearing surfaces or exchangeable necks were excluded. Cumulative percent revision was used to help compare survivorship between stems.ResultsThere were 201,889 total hip replacements meeting the inclusion criteria, of which 50.0% were cemented and 50.0% cementless. Cemented stems had a lower rate of revision at all time points compared to cementless stems. This was most significant during the first 2 weeks (hazard ratio 0.48, 95% confidence interval 0.40-0.58, P < .001) compared to 2 weeks postoperatively and onwards (hazard ratio 0.85, 95% confidence interval 0.81-0.90, P < .001). A subanalysis of head size, bearing type, and surgeon volume further supported the use of a cemented stem.ConclusionCommonly used cemented polished tapered stems have a lower revision rate when compared to commonly used cementless prostheses, and are recommended in all age groups for both low-volume and high-volume surgeons especially when head size 32 mm or smaller is used.     

Results of a hydroxyapatite-coated modular femoral stem in primary total hip arthroplasty. A minimum 5-year follow-up

The use of a modular metaphyseal-diaphyseal femoral stem in primary total hip arthroplasty is infrequent. We analyze 94 ESOP (Fournitures Hospitalieres, Heimsbrunn, France) cementless 2-piece modular stems after a minimum 5 years of follow-up. There were 2 aseptic femoral stem loosenings and no cases with thigh pain. Mean femoral canal filling was 90%. Radiographic ingrowth was obtained in 83 (P < .001). At 7 years, the survival rate for femoral aseptic loosening was 97.8% and no stem was at risk for revision (95% confidence interval, 94.8%-100%). This prosthesis provides good clinical results with absence of pain and excellent radiographic results. It is an option in femora with good bone quality. Femoral osteopenia and cortical widening were infrequent, and the modular metaphyseal-diaphyseal junction was not a problem in vivo.     

Cementless Modular Total Hip Arthroplasty in Patients Younger than Fifty with Femoral Head Osteonecrosis: Minimum Fifteen-Year Follow-Up

This study aimed to report the outcome of total hip arthroplasty (THA) with a modular femoral component in patients younger than fifty years with osteonecrosis of femoral head. Sixty-four osteonecrotic hips in fifty-five patients were available for clinical and radiographic analyses at minimum follow-up of fifteen-years. The mean Harris hip score improved from 36 points preoperatively to 92.7 points at final follow-up. Sixty-two (95.3%) hips demonstrated stable bone ingrowth. No hips showed loosening or required revision for aseptic loosening. Survivorship with an end point of stem revision for any reason was 93.8% and for aseptic loosening was 100% at 16.8 years. We believe that cementless THA with a modular stem is a promising procedure for young and active patients with osteonecrosis of the femoral head.     

What Is the Difference Between Modular and Nonmodular Tapered Fluted Titanium Stems in Revision Total Hip Arthroplasty

Background

Both modular and nonmodular tapered fluted titanium stems are used in revision total hip arthroplasty (THA), with follow-up showing good results for both stems. We aimed to determine whether there were any differences in clinical outcomes, survivorship, or frequency of complications.

A prospective outcomes analysis of femoral component fixation in revision total hip arthroplasty

A prospective, surgeon-allocated, matched cohort analysis of patient outcomes compared cementless, modular metaphyseal and cemented femoral fixation used for revision total hip arthroplasty. First-time femoral revision operations (with and without acetabular revision) with Paprosky types I and II femoral bone stock were included. This series of 86 patients was matched for age, weight, diagnosis, Charnley class, Demand category, femoral bone stock, and outcome measures. At 8-year average follow-up (range, 4-13 years), there were no significant differences in visual analog pain scores (VAPS), Harris Hip Scores (HSS), and SF-36 Physical Function and Bodily Pain scores. One femoral rerevision (2.3%) occurred in the cementless group, and 2 (4.6%) occurred in the cemented group (P = .557). Five-year survivorship for femoral rerevision was 94% for patients with cementless, modular metaphyseal fixation and 92% for patients with cemented fixation. In this study, cementless, modular metaphyseal fixation and cemented femoral fixation were both successful at intermediate-term follow-up in Paprosky types I and II femoral bone (level of evidence: therapeutic study; level II, prospective comparative study).     

Intermediate-term radiographic and patient outcomes in revision hip arthroplasty with a modular calcar design and porous plasma coating

This study is a retrospective evaluation of the intermediate-term results of 26 consecutive revision total hip arthroplasties performed with a modular titanium, uncemented femoral component. The average patient age at the time of revision total hip arthroplasty was 72 years, and there were an equal number of males and females. The mean follow-up was 5.7 years (ranging from 4 to 11 years). No re-revision was necessary during this follow-up time. The mean Harris hip score improved significantly (preoperative and postoperative score was 50.7 and 89.6, respectively; P < .001). Postoperatively, Short Form 36 functional scores averaged 67.7 across 9 functional parameters. Our observed low revision rate and favorable patient-reported outcome scores support the continuous use of modular titanium, uncemented femoral components in revision total hip arthroplasty.     

The Effect of Size for a Hydroxyapatite-Coated Cementless Implant on Component Revision in Total Hip Arthroplasty: An Analysis of 41,265 Stems

BackgroundThe cementless Corail is one of the most commonly used stems in total hip arthroplasty (THA). The aim of this study was to investigate whether there was a difference in revision rate for smaller stems.MethodsAll primary THA procedures recorded by the Australian Joint Replacement Registry from September 1999 to December 2017 performed for osteoarthritis using the Corail stem, a cementless acetabular cup, modern bearing surfaces (ceramic/ceramic, ceramic/cross-linked polyethylene, and metal/cross-linked polyethylene), and 28 mm, 32 mm, and 36 mm head sizes were included. The primary outcome measure was femoral component revision. Data were analyzed and adjusted for age, gender, and head size. Further analysis investigated the effects of surgical approach.ResultsThere was 41,265 primary THAs recorded. The cumulative percent revision (CPR) at 13 years was 7.7% (5.5, 10.7) for stem sizes 8 and 9 and 3.0% (2.4, 3.8) for sizes 10-20 (P < .001). When adjusted for age and gender, the sizes 8 and 9 collared (hazard ratio [HR]: 6.22 [3.84-10.06], P < .001) and collarless (HR: 3.28 [2.41-4.45], P < .001) had a higher CPR than the collared and collarless size 10-20. The size 8 and 9 stems performed with an anterior approach had the highest CPR (HR: 14.44 [6.21-33.56], P < .001). The main reason for revision of size 8 and 9 femoral stems was loosening (65.2%, compared to 31.5% for 10-20 femoral stems).ConclusionsSmaller Corail stems have 4 times the rate of revision compared with the larger femoral sizes with loosening being the most common diagnosis. This is most evident when using an anterior approach.     

Impact of Femoral Stem Design on Failure After Anterior Approach Total Hip Arthroplasty

Background

An increased rate of complications related to femoral component failure has been described with less invasive total hip arthroplasty (THA). This study evaluated the incidence of femoral complications associated with the direct anterior approach for THA.