Long-Term Clinical Results of Calcar Loading with Lateral Flare Anatomic Cementless Stem in Patients Younger Than 50 Years

Long-Term Clinical Results of Calcar Loading with Lateral Flare Anatomic Cementless Stem in Patients Younger Than 50 Years | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Long-Term Clinical Results of Calcar Loading with Lateral Flare Anatomic Cementless Stem in Patients Younger Than 50 Years Young-Hoo Kim, Jang-Won Park, Young-Soo Jang, Eun-Jung Kim This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6043438/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction The purpose of this study was to evaluate the long-term clinical results (minimum 20 years) the ultra-short anatomic cementless stem in patients < 50 years of age. Materials and Methods We reviewed the 336 patients (421 hips) who had a cementless total hip arthroplasty (THA) in patients < 50 years (46 ± 3 years) at the time of surgery. The most common diagnoses were osteonecrosis (47%) and developmental dysplasia (37%). Demographic data, the Harris hip score, Western Ontario and McMaster Universities Osteoarthritic Index (WOMAC), and the University of California, Los Angeles (UCLA) activity scores were recorded. The minimum follow-up interval was 20 years (mean, 21.5 years; range, 20 to 24 years). Results At the time of final follow-up, the mean Harris hip score, WOMAC score, and UCLA activity score were 93 points, 15 points, and 8 points, respectively. All but 7 patients had no thigh pain at the final follow-up. Seven hips (1.7%) had aseptic loosening of the stem. Survival rate at 24 years after the operation was 99.1% for the acetabular component and 96.4% for the femoral component. Conclusions These results in patients < 50 years of age suggest that this calcar loading with lateral flare anatomic cementless hip prosthesis provides good long-term fixation. Moreover, the alumina ceramic-on-alumina ceramic bearing provides a high rate of survivorship without osteolysis. Clinical results bone remodeling calcar loading lateral flare anatomic femoral stem Figures Figure 1 Figure 2 Figure 4 Figure 5 Introduction Due to improved total hip prosthesis designs and surgical techniques, indication for total hip arthroplasty (THA) now include younger and more active patients with higher demands. Considering cementless THA are used in young patients, short-stem THA has recently gained popularity as it preserves femoral bone stock and is also assumed to provide a more physiological load transfer compared to conventional cementless THA [ 1 – 4 ]. Various studies have reported a good short-and medium-term outcome [ 5 – 7 ]. Nevertheless, long-term studies (> 20 years) explicitly proofing the clinical results are not available yet. Conservative calcar loading with lateral flare anatomic cementless femoral stem (Fig. 1 ) was developed to reduce the periprosthetic fracture, thigh pain, and stress shielding. This ultra-short stem requires less resection of the upper femur and/or less reaming of the femoral shaft. This serves a dual purpose of facilitating future revision while providing a postoperative state closely mimicking originally functioning hip [ 5 , 6 , 8 – 10 ]. There is limited information on the long-term (> 20 years) clinical results of this calcar loading with lateral flare anatomic cementless femoral stem in patients < 50 years of age. The purpose of this long-term (minimum 20 years) follow-up study was to determine: (1) clinical results; (2) radiographic results, including rates of osseointegration and bone remodeling, as well as osteolysis; (3) rates of complications including thigh pain, periprosthetic fracture, and evidence of clicking or squeaking sounds; (4) rates of revision; and (5) survival rates of implants with the 4th generation of alumina ceramic-on-alumina ceramic articulation in patients < 50 years. Materials and Methods Inclusion and exclusion Criteria From January 2001 to January 2004, the senior author performed 446 cementless THAs in 361 consecutive patients who were younger than 50 years. We included all consecutive patients who had an end-stage hip disease. Exclusion criteria in this study were patients with diagnosis of active infection in the joint or body, or a neuromuscular disorder. The operations were performed by one surgeon at one institution. Demographics and Follow-up Of the 361 patients 336 patients (421 hips) were available at a mean of 21.5 years (range, 20 to 24 years) follow-up. Six patients (6 hips) declined to participate in the study, 3 (3 hips) died, and 16 (16 hips) who moved abroad were lost to follow-up (before one year) (Fig. 1 ). The study protocol, including the consent forms, was approved by the institutional review board at our patients. The study group comprised 177 male and 159 female patients. The mean age (and standard deviation) at the time of surgery was 46 ± 3 years (range, 21 to 49 years). The mean body weight was 65 ± 13 kg (range, 51 to 112 kg), the mean height was 164 ± 10 cm (range, 148 to 186 cm) and the mean body mass index was 28 ± 4 kg/m 2 (range, 21 to 38 kg/m 2 ). The preoperative diagnosis was femoral head osteonecrosis for 158 patients (47%), developmental dysplastic of the hip for 125 (37%), osteoarthritis for 31 (9%), traumatic arthritis for 12 (4%), childhood sepsis for 5 (1.5%), Legg-Perthes disease for 3 (0.8%), and rheumatoid arthritis for 2 (0.6%). The mean duration of follow-up was 21.5 years (range, 20 to 24 years). The presumed cause of the osteonecrosis was alcohol abuse in 291 (69%) of 421 hips, idiopathic in 118 (28%), chronic corticosteroid treatment for bronchial asthma or skin disease in 8 (2%), and posttraumatic in 4 (1%). No patient with alcohol or corticosteroid-induced osteonecrosis had an associated severe medical problem 11–15 (Table Ⅰ). Surgery and After care All of the procedures were performed by the senior author using a posterolateral approach. A fully porous-coated cementless pinnacle acetabular component (DePuy, Warsaw, Indiana) with a 32-mm or 36-mm (inner diameter) Biolox delta ceramic liner (Ceram Tec Ag, Polchingen, Germany) was used in all hips. All patients received a calcar loading with lateral flare anatomic cementless femoral stem (Proxima; DePuy, Leeds, United Kingdom) with a 32-mm or 36-mm Biolox delta ceramic modular head (Ceram Tec) (Fig. 2 ). The femoral neck was cut horizontally at the cervico-capital juncture, because preservation of the femoral neck is requized for axial and torsional stability of the stem [ 9 , 16 ]. A “round-the corner” technique [ 5 , 9 ] was used for femoral broaching and insertion of the implant. The patients were allowed to stand on the second postoperative day, and then progressed to full weight-bearing with crutches as tolerated. They were advised to use a pair of crutches for 6 weeks and walk with a cane thereafter as needed. Clinical Assessments We followed-up on patients at 3 months and 1 year postoperatively and there every 4 or 5 years thereafter. We obtained Harris hip score [ 17 ] and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score [ 18 ] preoperatively and at each follow-up examination. Thigh pain was measured at the latest follow-up using a 10-point visual analog scale (with 0 indicating no pain and 10, severe pain). We used the University of California, Los Angeles (UCLA) activity score [ 19 ] to assess patient’s activity level. The occurrence of any clicking or squeaking sound emanating from the ceramic-on-ceramic bearing was recorded. Radiographic Analysis A research associate who had no knowledges of the patient’s identity analyzed the radiographs. A supine anteroposterior radiograph of the pelvis with both hips in neutral rotation and no abduction was made for every patient. Anterversion of the acetabular component was measured on the lateral radiograph of the hip as the angle between the horizontal line where the film cassette rested on the X-ray table and a second line marking the plane of the opening of the acetabular component. Definite loosening of the femoral component was defined as a progressive axial subsidence of > 3 mm, or a varus or valgus shift of > 3° [ 20 ]. Definite loosening of the acetabular component was diagnosed when a change in the position of the component (> 2 mm vertically and / or medially or laterally) or a continuous radiolucent line of > 2 mm on both the anteroposterior and the lateral radiographs was seen [ 21 ]. The sites of any osteolysis in the acetabulum were recorded according to the classification of De Lee and Charnley [ 22 ] and those in the femur, by the classification of Gruen et al. [ 23 ]. Proximal femoral bone resorption was graded radiographically [ 24 ]. Measurement of the linear wear of the alumina ceramic liner was attempted but was below the level of detection by method of Kim et al. [ 25 ]. Osteolysis was defined as any discretely localized radiolucency that had been absent on radiographs made immediately after the THA. Heterotopic ossification, if present, was graded according to the classification of Brooker et al. [ 26 ]. Bone Mineral Density Analysis Two hundred and eighty-six patients (85% of 336 patients) underwent dual-energy X-ray absorptiometry scanning of the pelvis and proximal femur (zones 1 and 7) between 20 and 24 years after surgery using a Hologic QDR 4500A densitometer (Hologic Inc, Waltham, MA, USA) in the metal removal hip scanning mode 2 weeks after surgery, which served as a baseline of bone mineral density (BMD) for the subsequent scans. Further scans were obtained at final follow-up [ 8 ]. (Fig. 3 ) Statistical Analysis The changes in Harris hip score were evaluated using a paired t test. WOMAC and UCLA activity scores and BMD results also were evaluated using a paired t test. The Chi square test with Yate’s correction was used to analyze complication rates and radiographic data. Kaplan-Meier survival analysis [ 27 ] was performed with revision for any cause or aseptic loosening as the end point. All statistical analyses were performed using SPSS version 14.0 (SPSS Inc, Chicago, IL, USA). Statistical significance was set at p values of < 0.05. Results Clinical Results The clinical and functional results improved for the Harris hip score, WOMAC, and UCLA activity scores (Table Ⅱ). The mean preoperative Harris hip score was 48 ± 9 points (range, 9 to 51 points), which improved to a mean of 93 ± 11 points (range, 75 to 100 points) at the time of the final-up. The mean WOMAC score was 65 ± 15 points (range, 41 to 89 points) preoperatively and 15 ± 6 points (range, 4 to 29 points) at the time of the final follow-up. The mean preoperative UCLA activity score was 3 points (range, 1 to 4 points) which improved to a mean of 8 points (range, 6 to 10 points) at the time of the final follow-up. The prevalence of thigh pain (3 points on the visual analog scale) was 1.7% (7 of 421 hips) due to aseptic loosening of the femoral component. Seventy hips (17%) displayed clicking sound and 38 hips (9%) displayed squeaking sound. (Table Ⅱ). Radiographic Results Preoperatively, 362 hips (86%) were Dorr type A, 21 (5%) were type B, and 38 (9%) were type C. As seen of the postoperative radiographs, 341 femoral stems (81%) were neutral, 72 (17%) were in varus (< 5°), and 8 (2%) were in valgus (< 5°). The mean inclination and anteversion of the acetabular component were 44° (range, 37° to 49°) and 21° (range, 17° to 25°), respectively (Table Ⅲ). All acetabular components and all but 7 femoral component had osseous integration. Three hundred and ninety-nine hips (95%) exhibited Grade 1 stress shielding in the calcar region 24 and 22 (5%) had Grade 2 stress shielding. No hip exhibited Grade 3 stress shielding. No acetabular of femoral osteolysis was identified in any hip. (Figs. 4 -A and 4 -B). Bone Mineral Density Around the femoral component, BMD was significantly reduced in zone 7 and slightly increased in zone 1 by final review (Table Ⅳ). Complications A deep early postoperative infection developed in 3 hips (0.7%), and these 3 hips were revised by 2 stage. No hip had an aseptic loosening occurred. Two hips (0.5%) had an intraoperative calcar femoral fracture, which were fixed with a cable. One hip (0.2%) had a recurrent dislocation and this was revised with a constrained cup. There was no further dislocation. No hip had a grade 3 or 4 heterotopic ossification. Revision One acetabular component (0.2%) was revised for a recurrent dislocation and 3 cups (0.7%) were revised for infection. Seven femoral stems (1.7%) were revised for aseptic loosening, 5 stems (1.2%) were revised for periprosthetic fracture and 3 stems (0.7%) were revised for infection Survivorship Kaplan-Meier survivorship analysis [ 27 ] (Fig. 5 ) revealed that the rate of survival of the femoral component at 24 years was 99.3% (95% confidence interval, 94–100%) with loosening or revision considered the end point for failure, and the rate of survival of the acetabular component was 99.1% (95% confidence interval, 94–100%) at 24 years, with loosening or revision considered as the end point for failure. Discussion Up to 24 years, in the current study, we achieved excellent clinical results, secure implant stability with reduction in adaptive bone loss, low complication rates, low revision rates, and high survival rates with this calcar loading with lateral flare anatomic cementless femoral stem in patients younger than 50 years of age. Our results are consistent with those from other studies [ 5 , 6 , 8 – 10 – 15 , 20 ]. Several authors [ 5 , 6 , 9 , 28 ] reported high Harris hip score in the younger patients. In the current study, our patients had high hip scores resulting from isolated instances of unilateral or bilateral hip disease and the absence of systemic disease, severe hip deformities preoperatively, or previous hip procedures. A tight distal fill by a rigid femoral stem [ 11 – 15 , 20 , 28 , 29 ] causes thigh pain. In our current series, axial and torsional stability of the stem and absence of contact between the stem and the inner cortex of the femur contributed the low prevalence of thigh pain. It has been reported in the previous studies [ 11 – 15 , 24 , 28 , 30 , 31 ] that the current generation of cementless total hip prostheses in young patients is quite encouraging [ 11 – 15 , 24 , 28 , 30 , 31 ]. Clohisy et al. [ 28 ] suggested that cementless fixation combined with improved THA bearing materials may lead to long-term survivorship, even in the young patient population. Adelani et al. [ 32 ] concluded that radiographic loosening and revision rates have decreased substantially over time in very young patients undergoing THA with the advent of contemporary surgical techniques and implants. It has been reported in the previous studies of the cementless stem with ceramic-on-ceramic bearings in patients younger than 45 years, no hip had a mechanical failure [ 33 , 34 ]. We showed in the present study that this hip system had a low rate of mechanical failure (1.7% at 21.5 years) despite a higher activity level. Several studies of the 3rd-generation alumina ceramic bearings have found little or osteolysis [ 35 , 36 ]. In our current study, extremely low wear and the scant damage of the optimally positioned articular surfaces were insufficient to cause osteolysis. Survivorship of THA in young patients is poorer than that seen in older cohorts [ 28 – 31 ]. Younger patients may have acquired disease from varied cause, and they tend to have higher activity levels than those of older patients. Although, the majority of patient in our series continued to participate in high-demand activities, the level of activity did not seem to affect the longevity of fixation of the components. We believe several factors were responsible for our good results: the proximal fitting design of the femoral stem (including pronounced lateral flare, anteroposterior build up, and high femoral neck cut); a surgical technique that optimized fit; the strong trabecular bone in young patients; patients who were small and light; absence of comorbidities; the utilization of an alumina-on-alumina ceramic articulation; and relatively consistent and optimal alignment of the acetabular component, avoiding impingement. There are several limitations in this study. First, although the data were collected prospectively, the study was retrospective in design, not randomized, and used no control group. Second, we did not use radiostereometric analysis to evaluate for migration; radiostereometric analysis is known to be more precise than manual techniques of measurement [ 37 ]. Third, the performance of all operations by a single surgeon may introduce a bias into interpretation data. However, our findings were similar to other published results [ 5 , 6 , 9 ] between the current series and other studies appears to mitigate single-surgeon bias. Finally, one potential argument is that although the stem is short and does not violate much of the medullary canal, it is quite thick proximally and extends a good distance laterally into the greater trochanter. Thus, it might lead to more difficulties at the time of revision than more conventional proximally coated cementless components, which are thinner proximally. In conclusion, a calcar loading with lateral flare anatomic cementless stem with alumina-ceramic-on-alumina ceramic bearings in patients < 50 years of age provided outstanding long-term fixation and pain relief well into the 3rd decade after surgery and provide a high rate of survivorship without evidence of osteolysis. Declarations Funding No funding was received for this study. Author Contribution The study conception and design were contributed by Young-Hoo Kim, MD and Jang-Won Park, MD. Material preparation, data collection, and analysis were performed by Doori Kim, BA, Eun-Jung Kim, MD, and Young-Soo Jang, MD. The First draft of the manuscript was written by Young-Hoo Kim, MD, and all authors read and approved the final manuscript. Acknowledgement The authors express great thanks to Doo-Ri Kim, BA for her collection and analyzing data Data Availability “Data is provided within the manuscript or supplementary information files”. 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A five-year minimum follow-up study. J Bone Joint Surg Am 87(3):530–535 Börlin N, Thien T, Kärrholm J (2002) The precision of radiostereometric measurements. J Biomech 35(1):69–79 Tables Tables 1 to 4 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.docx Table2.docx Table3.docx Table4.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6043438","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":417882485,"identity":"9283fd06-9290-4261-b671-52611328d01e","order_by":0,"name":"Young-Hoo Kim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7klEQVRIiWNgGAWjYLACxgYGBglmBsYHDAwH4AJEaWE2IFELAwObBFFaDI73mD38usNGTrKdO63iY9sdeQb2ww8YZ+7Bo+XMGXNj2TNpxtLMvNtuzmx7ZtjAk2bAuOEZHi03csykJdsOJ84DarnNu+0w0E05wIA4QKSW4r/bDts38L8hrEXyI1DLbKAWZsZthxMbJIC2bMCjRfLMsTJpxrY0Y8lm3s2Svf8OJ7dJPDM4OAOPFr7jzdskf7bZyEmcP7vxw48zh237+ZMfPuzBo0UBKMfMgyzCxgCLHRxAvgEYcT/wqRgFo2AUjIJRAACFAVihM+bZzgAAAABJRU5ErkJggg==","orcid":"","institution":"Seoul Metropolitan Government SeoNam Hospital","correspondingAuthor":true,"prefix":"","firstName":"Young-Hoo","middleName":"","lastName":"Kim","suffix":""},{"id":417882487,"identity":"ca370081-97f0-4cff-bb4f-48cc9aa18791","order_by":1,"name":"Jang-Won Park","email":"","orcid":"","institution":"Ewha Womans University Seoul Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jang-Won","middleName":"","lastName":"Park","suffix":""},{"id":417882488,"identity":"4ba49903-0d2f-40ce-ab5b-b2fa94c72edb","order_by":2,"name":"Young-Soo Jang","email":"","orcid":"","institution":"Seoul Metropolitan Government SeoNam Hospital","correspondingAuthor":false,"prefix":"","firstName":"Young-Soo","middleName":"","lastName":"Jang","suffix":""},{"id":417882489,"identity":"3066c875-5872-45c1-b957-a22ded802598","order_by":3,"name":"Eun-Jung Kim","email":"","orcid":"","institution":"Seoul Metropolitan Government SeoNam Hospital","correspondingAuthor":false,"prefix":"","firstName":"Eun-Jung","middleName":"","lastName":"Kim","suffix":""}],"badges":[],"createdAt":"2025-02-17 00:53:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6043438/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6043438/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":77284599,"identity":"5f8d2e4b-1ec9-4b5a-87f9-b084e80bfbca","added_by":"auto","created_at":"2025-02-27 05:07:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1145162,"visible":true,"origin":"","legend":"\u003cp\u003eThe Consolidated Standards of Reporting Trials (CONSORT) flow diagram of patients in this study.\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/89154a476cb1f052cd205791.png"},{"id":77284285,"identity":"a5bf4c83-9835-496b-a6cc-45c019edb5fd","added_by":"auto","created_at":"2025-02-27 04:59:45","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":4764742,"visible":true,"origin":"","legend":"\u003cp\u003eA photograph of the calcar loading with lateral flare ultra-short anatomic cementless femoral stem. This stem is designed with longer proximomedial portion and a highly pronounced lateral flare and allows for preservation of the femoral neck.\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/22e65944013f635a60626fe7.png"},{"id":77283365,"identity":"e967deed-904e-4854-b427-32c3685e9de4","added_by":"auto","created_at":"2025-02-27 04:51:45","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":800752,"visible":true,"origin":"","legend":"\u003cp\u003eAnteroposterior and lateral radiographs of a 38-year-old man with osteonecrosis of both femoral heads taken 21 years after the operation. The acetabular and femoral components are well fixed in a satisfactory position without osteolysis.\u003c/p\u003e","description":"","filename":"Fig.4A.png","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/25cf4c5b7957a7f01c9abaca.png"},{"id":77284288,"identity":"d31139aa-9ef6-444d-9fc3-3b77b9ca8412","added_by":"auto","created_at":"2025-02-27 04:59:45","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":980029,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier survival rate at 0-24 years with the total hip arthroplasty components.\u003c/p\u003e","description":"","filename":"Fig.5.png","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/3883412083e054d150ccef7e.png"},{"id":77286211,"identity":"8160ddb7-e025-4d27-9e4d-1d7a3b532b25","added_by":"auto","created_at":"2025-02-27 05:33:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":8405371,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/d177f7f4-6ea5-4015-beca-a86b392ff792.pdf"},{"id":77283358,"identity":"ae687ee4-c47d-414b-ab1d-9e0c6a264347","added_by":"auto","created_at":"2025-02-27 04:51:45","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":15687,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/8215eff9274d23582253423f.docx"},{"id":77284597,"identity":"ffbe9712-1f14-47ee-89eb-941430ec4a98","added_by":"auto","created_at":"2025-02-27 05:07:45","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":17791,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/7d7384a874f9f154f97d20f8.docx"},{"id":77283367,"identity":"5c924fff-9682-43f3-9ecf-03c4c6185d40","added_by":"auto","created_at":"2025-02-27 04:51:45","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":16205,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.docx","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/e2a0a35fb86147337d5d8bea.docx"},{"id":77284279,"identity":"2f214d64-4c50-432d-a2be-529765894f9c","added_by":"auto","created_at":"2025-02-27 04:59:45","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":13962,"visible":true,"origin":"","legend":"","description":"","filename":"Table4.docx","url":"https://assets-eu.researchsquare.com/files/rs-6043438/v1/ea5ceccbc7dedb6679996291.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Long-Term Clinical Results of Calcar Loading with Lateral Flare Anatomic Cementless Stem in Patients Younger Than 50 Years","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDue to improved total hip prosthesis designs and surgical techniques, indication for total hip arthroplasty (THA) now include younger and more active patients with higher demands. Considering cementless THA are used in young patients, short-stem THA has recently gained popularity as it preserves femoral bone stock and is also assumed to provide a more physiological load transfer compared to conventional cementless THA [\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Various studies have reported a good short-and medium-term outcome [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Nevertheless, long-term studies (\u0026gt;\u0026thinsp;20 years) explicitly proofing the clinical results are not available yet.\u003c/p\u003e \u003cp\u003eConservative calcar loading with lateral flare anatomic cementless femoral stem (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) was developed to reduce the periprosthetic fracture, thigh pain, and stress shielding. This ultra-short stem requires less resection of the upper femur and/or less reaming of the femoral shaft. This serves a dual purpose of facilitating future revision while providing a postoperative state closely mimicking originally functioning hip [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. There is limited information on the long-term (\u0026gt;\u0026thinsp;20 years) clinical results of this calcar loading with lateral flare anatomic cementless femoral stem in patients\u0026thinsp;\u0026lt;\u0026thinsp;50 years of age.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe purpose of this long-term (minimum 20 years) follow-up study was to determine: (1) clinical results; (2) radiographic results, including rates of osseointegration and bone remodeling, as well as osteolysis; (3) rates of complications including thigh pain, periprosthetic fracture, and evidence of clicking or squeaking sounds; (4) rates of revision; and (5) survival rates of implants with the 4th generation of alumina ceramic-on-alumina ceramic articulation in patients\u0026thinsp;\u0026lt;\u0026thinsp;50 years.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eInclusion and exclusion Criteria\u003c/h2\u003e \u003cp\u003eFrom January 2001 to January 2004, the senior author performed 446 cementless THAs in 361 consecutive patients who were younger than 50 years. We included all consecutive patients who had an end-stage hip disease. Exclusion criteria in this study were patients with diagnosis of active infection in the joint or body, or a neuromuscular disorder. The operations were performed by one surgeon at one institution.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eDemographics and Follow-up\u003c/h3\u003e\n\u003cp\u003eOf the 361 patients 336 patients (421 hips) were available at a mean of 21.5 years (range, 20 to 24 years) follow-up. Six patients (6 hips) declined to participate in the study, 3 (3 hips) died, and 16 (16 hips) who moved abroad were lost to follow-up (before one year) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The study protocol, including the consent forms, was approved by the institutional review board at our patients.\u003c/p\u003e \u003cp\u003eThe study group comprised 177 male and 159 female patients. The mean age (and standard deviation) at the time of surgery was 46\u0026thinsp;\u0026plusmn;\u0026thinsp;3 years (range, 21 to 49 years). The mean body weight was 65\u0026thinsp;\u0026plusmn;\u0026thinsp;13 kg (range, 51 to 112 kg), the mean height was 164\u0026thinsp;\u0026plusmn;\u0026thinsp;10 cm (range, 148 to 186 cm) and the mean body mass index was 28\u0026thinsp;\u0026plusmn;\u0026thinsp;4 kg/m\u003csup\u003e2\u003c/sup\u003e (range, 21 to 38 kg/m\u003csup\u003e2\u003c/sup\u003e). The preoperative diagnosis was femoral head osteonecrosis for 158 patients (47%), developmental dysplastic of the hip for 125 (37%), osteoarthritis for 31 (9%), traumatic arthritis for 12 (4%), childhood sepsis for 5 (1.5%), Legg-Perthes disease for 3 (0.8%), and rheumatoid arthritis for 2 (0.6%). The mean duration of follow-up was 21.5 years (range, 20 to 24 years). The presumed cause of the osteonecrosis was alcohol abuse in 291 (69%) of 421 hips, idiopathic in 118 (28%), chronic corticosteroid treatment for bronchial asthma or skin disease in 8 (2%), and posttraumatic in 4 (1%). No patient with alcohol or corticosteroid-induced osteonecrosis had an associated severe medical problem\u003csup\u003e11\u0026ndash;15\u003c/sup\u003e (Table Ⅰ).\u003c/p\u003e\n\u003ch3\u003eSurgery and After care\u003c/h3\u003e\n\u003cp\u003eAll of the procedures were performed by the senior author using a posterolateral approach. A fully porous-coated cementless pinnacle acetabular component (DePuy, Warsaw, Indiana) with a 32-mm or 36-mm (inner diameter) Biolox delta ceramic liner (Ceram Tec Ag, Polchingen, Germany) was used in all hips. All patients received a calcar loading with lateral flare anatomic cementless femoral stem (Proxima; DePuy, Leeds, United Kingdom) with a 32-mm or 36-mm Biolox delta ceramic modular head (Ceram Tec) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The femoral neck was cut horizontally at the cervico-capital juncture, because preservation of the femoral neck is requized for axial and torsional stability of the stem [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. A \u0026ldquo;round-the corner\u0026rdquo; technique [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] was used for femoral broaching and insertion of the implant.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe patients were allowed to stand on the second postoperative day, and then progressed to full weight-bearing with crutches as tolerated. They were advised to use a pair of crutches for 6 weeks and walk with a cane thereafter as needed.\u003c/p\u003e\n\u003ch3\u003eClinical Assessments\u003c/h3\u003e\n\u003cp\u003eWe followed-up on patients at 3 months and 1 year postoperatively and there every 4 or 5 years thereafter. We obtained Harris hip score [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] preoperatively and at each follow-up examination. Thigh pain was measured at the latest follow-up using a 10-point visual analog scale (with 0 indicating no pain and 10, severe pain). We used the University of California, Los Angeles (UCLA) activity score [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] to assess patient\u0026rsquo;s activity level.\u003c/p\u003e \u003cp\u003eThe occurrence of any clicking or squeaking sound emanating from the ceramic-on-ceramic bearing was recorded.\u003c/p\u003e\n\u003ch3\u003eRadiographic Analysis\u003c/h3\u003e\n\u003cp\u003eA research associate who had no knowledges of the patient\u0026rsquo;s identity analyzed the radiographs. A supine anteroposterior radiograph of the pelvis with both hips in neutral rotation and no abduction was made for every patient. Anterversion of the acetabular component was measured on the lateral radiograph of the hip as the angle between the horizontal line where the film cassette rested on the X-ray table and a second line marking the plane of the opening of the acetabular component.\u003c/p\u003e \u003cp\u003eDefinite loosening of the femoral component was defined as a progressive axial subsidence of \u0026gt;\u0026thinsp;3 mm, or a varus or valgus shift of \u0026gt;\u0026thinsp;3\u0026deg; [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Definite loosening of the acetabular component was diagnosed when a change in the position of the component (\u0026gt;\u0026thinsp;2 mm vertically and / or medially or laterally) or a continuous radiolucent line of \u0026gt;\u0026thinsp;2 mm on both the anteroposterior and the lateral radiographs was seen [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The sites of any osteolysis in the acetabulum were recorded according to the classification of De Lee and Charnley [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] and those in the femur, by the classification of Gruen et al. [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Proximal femoral bone resorption was graded radiographically [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Measurement of the linear wear of the alumina ceramic liner was attempted but was below the level of detection by method of Kim et al. [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Osteolysis was defined as any discretely localized radiolucency that had been absent on radiographs made immediately after the THA. Heterotopic ossification, if present, was graded according to the classification of Brooker et al. [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eBone Mineral Density Analysis\u003c/h2\u003e \u003cp\u003eTwo hundred and eighty-six patients (85% of 336 patients) underwent dual-energy X-ray absorptiometry scanning of the pelvis and proximal femur (zones 1 and 7) between 20 and 24 years after surgery using a Hologic QDR 4500A densitometer (Hologic Inc, Waltham, MA, USA) in the metal removal hip scanning mode 2 weeks after surgery, which served as a baseline of bone mineral density (BMD) for the subsequent scans. Further scans were obtained at final follow-up [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eThe changes in Harris hip score were evaluated using a paired t test. WOMAC and UCLA activity scores and BMD results also were evaluated using a paired t test. The Chi square test with Yate\u0026rsquo;s correction was used to analyze complication rates and radiographic data. Kaplan-Meier survival analysis [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] was performed with revision for any cause or aseptic loosening as the end point. All statistical analyses were performed using SPSS version 14.0 (SPSS Inc, Chicago, IL, USA). Statistical significance was set at p values of \u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eClinical Results\u003c/h2\u003e \u003cp\u003eThe clinical and functional results improved for the Harris hip score, WOMAC, and UCLA activity scores (Table Ⅱ). The mean preoperative Harris hip score was 48\u0026thinsp;\u0026plusmn;\u0026thinsp;9 points (range, 9 to 51 points), which improved to a mean of 93\u0026thinsp;\u0026plusmn;\u0026thinsp;11 points (range, 75 to 100 points) at the time of the final-up. The mean WOMAC score was 65\u0026thinsp;\u0026plusmn;\u0026thinsp;15 points (range, 41 to 89 points) preoperatively and 15\u0026thinsp;\u0026plusmn;\u0026thinsp;6 points (range, 4 to 29 points) at the time of the final follow-up. The mean preoperative UCLA activity score was 3 points (range, 1 to 4 points) which improved to a mean of 8 points (range, 6 to 10 points) at the time of the final follow-up. The prevalence of thigh pain (3 points on the visual analog scale) was 1.7% (7 of 421 hips) due to aseptic loosening of the femoral component. Seventy hips (17%) displayed clicking sound and 38 hips (9%) displayed squeaking sound. (Table Ⅱ).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eRadiographic Results\u003c/h2\u003e \u003cp\u003ePreoperatively, 362 hips (86%) were Dorr type A, 21 (5%) were type B, and 38 (9%) were type C. As seen of the postoperative radiographs, 341 femoral stems (81%) were neutral, 72 (17%) were in varus (\u0026lt;\u0026thinsp;5\u0026deg;), and 8 (2%) were in valgus (\u0026lt;\u0026thinsp;5\u0026deg;). The mean inclination and anteversion of the acetabular component were 44\u0026deg; (range, 37\u0026deg; to 49\u0026deg;) and 21\u0026deg; (range, 17\u0026deg; to 25\u0026deg;), respectively (Table Ⅲ). All acetabular components and all but 7 femoral component had osseous integration. Three hundred and ninety-nine hips (95%) exhibited Grade 1 stress shielding in the calcar region 24 and 22 (5%) had Grade 2 stress shielding. No hip exhibited Grade 3 stress shielding. No acetabular of femoral osteolysis was identified in any hip. (Figs.\u0026nbsp;\u0026lt;link rid=\"fig4\"\u0026gt;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u0026lt;/link\u0026gt;\u003c/span\u003e-A and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e-B).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eBone Mineral Density\u003c/h2\u003e \u003cp\u003eAround the femoral component, BMD was significantly reduced in zone 7 and slightly increased in zone 1 by final review (Table Ⅳ).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eComplications\u003c/h2\u003e \u003cp\u003eA deep early postoperative infection developed in 3 hips (0.7%), and these 3 hips were revised by 2 stage. No hip had an aseptic loosening occurred. Two hips (0.5%) had an intraoperative calcar femoral fracture, which were fixed with a cable. One hip (0.2%) had a recurrent dislocation and this was revised with a constrained cup. There was no further dislocation. No hip had a grade 3 or 4 heterotopic ossification.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eRevision\u003c/h2\u003e \u003cp\u003eOne acetabular component (0.2%) was revised for a recurrent dislocation and 3 cups (0.7%) were revised for infection. Seven femoral stems (1.7%) were revised for aseptic loosening, 5 stems (1.2%) were revised for periprosthetic fracture and 3 stems (0.7%) were revised for infection\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eSurvivorship\u003c/h2\u003e \u003cp\u003eKaplan-Meier survivorship analysis [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e] (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e) revealed that the rate of survival of the femoral component at 24 years was 99.3% (95% confidence interval, 94\u0026ndash;100%) with loosening or revision considered the end point for failure, and the rate of survival of the acetabular component was 99.1% (95% confidence interval, 94\u0026ndash;100%) at 24 years, with loosening or revision considered as the end point for failure.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eUp to 24 years, in the current study, we achieved excellent clinical results, secure implant stability with reduction in adaptive bone loss, low complication rates, low revision rates, and high survival rates with this calcar loading with lateral flare anatomic cementless femoral stem in patients younger than 50 years of age. Our results are consistent with those from other studies [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan additionalcitationids=\"CR11 CR12 CR13 CR14\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSeveral authors [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] reported high Harris hip score in the younger patients. In the current study, our patients had high hip scores resulting from isolated instances of unilateral or bilateral hip disease and the absence of systemic disease, severe hip deformities preoperatively, or previous hip procedures.\u003c/p\u003e \u003cp\u003eA tight distal fill by a rigid femoral stem [\u003cspan additionalcitationids=\"CR12 CR13 CR14\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] causes thigh pain. In our current series, axial and torsional stability of the stem and absence of contact between the stem and the inner cortex of the femur contributed the low prevalence of thigh pain.\u003c/p\u003e \u003cp\u003eIt has been reported in the previous studies [\u003cspan additionalcitationids=\"CR12 CR13 CR14\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] that the current generation of cementless total hip prostheses in young patients is quite encouraging [\u003cspan additionalcitationids=\"CR12 CR13 CR14\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Clohisy et al. [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] suggested that cementless fixation combined with improved THA bearing materials may lead to long-term survivorship, even in the young patient population. Adelani et al. [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] concluded that radiographic loosening and revision rates have decreased substantially over time in very young patients undergoing THA with the advent of contemporary surgical techniques and implants. It has been reported in the previous studies of the cementless stem with ceramic-on-ceramic bearings in patients younger than 45 years, no hip had a mechanical failure [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. We showed in the present study that this hip system had a low rate of mechanical failure (1.7% at 21.5 years) despite a higher activity level.\u003c/p\u003e \u003cp\u003eSeveral studies of the 3rd-generation alumina ceramic bearings have found little or osteolysis [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. In our current study, extremely low wear and the scant damage of the optimally positioned articular surfaces were insufficient to cause osteolysis.\u003c/p\u003e \u003cp\u003eSurvivorship of THA in young patients is poorer than that seen in older cohorts [\u003cspan additionalcitationids=\"CR29 CR30\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Younger patients may have acquired disease from varied cause, and they tend to have higher activity levels than those of older patients. Although, the majority of patient in our series continued to participate in high-demand activities, the level of activity did not seem to affect the longevity of fixation of the components. We believe several factors were responsible for our good results: the proximal fitting design of the femoral stem (including pronounced lateral flare, anteroposterior build up, and high femoral neck cut); a surgical technique that optimized fit; the strong trabecular bone in young patients; patients who were small and light; absence of comorbidities; the utilization of an alumina-on-alumina ceramic articulation; and relatively consistent and optimal alignment of the acetabular component, avoiding impingement.\u003c/p\u003e \u003cp\u003eThere are several limitations in this study. First, although the data were collected prospectively, the study was retrospective in design, not randomized, and used no control group. Second, we did not use radiostereometric analysis to evaluate for migration; radiostereometric analysis is known to be more precise than manual techniques of measurement [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Third, the performance of all operations by a single surgeon may introduce a bias into interpretation data. However, our findings were similar to other published results [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] between the current series and other studies appears to mitigate single-surgeon bias. Finally, one potential argument is that although the stem is short and does not violate much of the medullary canal, it is quite thick proximally and extends a good distance laterally into the greater trochanter. Thus, it might lead to more difficulties at the time of revision than more conventional proximally coated cementless components, which are thinner proximally.\u003c/p\u003e \u003cp\u003eIn conclusion, a calcar loading with lateral flare anatomic cementless stem with alumina-ceramic-on-alumina ceramic bearings in patients\u0026thinsp;\u0026lt;\u0026thinsp;50 years of age provided outstanding long-term fixation and pain relief well into the 3rd decade after surgery and provide a high rate of survivorship without evidence of osteolysis.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eNo funding was received for this study.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eThe study conception and design were contributed by Young-Hoo Kim, MD and Jang-Won Park, MD. Material preparation, data collection, and analysis were performed by Doori Kim, BA, Eun-Jung Kim, MD, and Young-Soo Jang, MD. The First draft of the manuscript was written by Young-Hoo Kim, MD, and all authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors express great thanks to Doo-Ri Kim, BA for her collection and analyzing data\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003e\u0026ldquo;Data is provided within the manuscript or supplementary information files\u0026rdquo;.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSumner DR (2015) Long-term implant fixation and stress-shielding in total hip replacement. J Biomech 48(5):797\u0026ndash;800\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKobayashi S, Saito N, Horiuchi H, Iorio R, Takaoka K (2000) Poor bone quality or hip structure as risk factors affecting survival of total hip arthroplasty. Lancet 355(9214):1499\u0026ndash;1504\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDecking R, Rokahr C, Zurstegge M, Simon U, Decking J (2008) Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis. BMC Musculoskelet Disord 9:17\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLerch M, von der Haar-Tran A, Windhagen H, Behrens BA, Wefstaedt P, Stukenborg-Colsman CM (2012) Bone remodeling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study. Int Orthop 36(3):533\u0026ndash;538\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Kim J-S, Joo J-H, Park J-W (2012) A prospective short-term outcome study of a short metaphyseal fitting total hip arthroplasty. J Arthroplasty 27(1):88\u0026ndash;94\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Park J-W, Kim J-S (2013) Behavior of the ultra-short anatomic cementless femoral stem in young patients and elderly patients. Int Orthop 37(12):2323\u0026ndash;2330\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchmidutz F, Graf T, Mazoochian F, Fottner A, Bauer-Melnyk A, Jansson V (2012) Migration analysis of a metaphyseal anchored short-stem hip prosthesis. Acta Orthop 83(4):360\u0026ndash;365\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Choi Y-W, Kim J-S (2011) Comparison of bone mineral density changes around short, metaphyseal-fitting and conventional cementless anatomical femoral components. J Arthroplasty 26(6):931\u0026ndash;940\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSantori FS, Santori N (2010) Mid-term results of a custom-made short proximal loading femoral component. J Bone Joint Surg Br 92(9):1231\u0026ndash;1237\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBraud P, Freeman MA (1990) The effect of retention of the femoral neck and of cement upon the stability of proximal femoral prosthesis. J Arthroplasty 5 Suppl: S5-10\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Kim J-S, Park J-W, Joo J-H (2011) Comparison of total hip replacement with and without cement in patients younger than 50 years of age: the results at 18 years. J Bone Joint Surg Br 93(4):449\u0026ndash;455\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Kook H-K, Kim J-S (2002) Total hip replacement with a cementless acetabular component and a cemented femoral component in patients younger than fifty years of age. J Bone Joint Surg Am 84(5):770\u0026ndash;774\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Kim J-S, Yoon S-H (2007) Long-term survivorship of the Charnley Elite Plus femoral component in young patients. J Bone Joint Surg Am 89(4):449\u0026ndash;454\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Oh S-H, Kim J-S (2003) Primary total hip arthroplasty with a second-generation cementless total hip prosthesis in patient younger than fifty years of age. J Bone Joint Surg Am 85(1):109\u0026ndash;114\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Choi Y, Kim J-S (2010) Cementless total hip arthroplasty with ceramic-on-ceramic bearing in patients younger than 45 years with femoral-head osteonecrosis. Int Orthop 34(8):1123\u0026ndash;1127\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWhiteside LA, White SE, McCarthy DS (1995) Effect of neck resection on torsional stability of cementless total hip replacement. Am J Orthop 24(10):766\u0026ndash;770\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHarris WH (1969) Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by mold arthroplasty. An end-result study using a new method of result evaluation. J Bone Joint Surg Am 51(4):737\u0026ndash;755\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBellamy N, Buchanan WW, Goldsmith CH, Campbell J, Stitt LW (1988) Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol 15(12):1833\u0026ndash;1840\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZahiri CA, Schmalzried TP, Szuszczewicz ES, Amstutz HC (1998) Assessing activity in joint replacement patients. J Arthroplasty 13(8):890\u0026ndash;895\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Kim J-S, Oh S-H, Kim J-M (2003) Comparison of porous-coated titanium femoral stems with and without hydroxyapatite coating. J Bone Joint Surg Am 85(9):1682\u0026ndash;1688\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSutherland CJ, Wilde AH, Borden LS, Marks KE (1982) A ten-year follow-up of one hundred consecutive M\u0026uuml;ller curved-stem total hip-replacement arthroplasties. J Bone Joint Surg Am 64(7):970\u0026ndash;982\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeLee JG, Charnley J (1976) Radiological demarcation of cemented sockets in total hip replacement. Clin Orthop Relat Res (121): 20\u0026ndash;32\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGruen TA, McNeice GM, Amstutz HC (1979) Modes of failure of cemented stem-type femoral components: a radiographic analysis of loosening. Clin Orthop Relat Res (141): 17\u0026ndash;27\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEngh CA, Bobyn JD, Glassman AH (1987) Porous-coated hip replacement. The factors governing bone ingrowth, stress shielding, and clinical results. J Bone Joint Surg Br 69(1):45\u0026ndash;55\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H, Kim J-S, Cho S-H (2001) A comparison of polyethylene wear in hips with cobalt-chrome or zirconia heads. A prospective, randomised study. J Bone Joint Surg Br 83(5):742\u0026ndash;750\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrooker AF, Bowerman JW, Robinson RA, Riley LH Jr (1973) Ectopic ossification following total hip replacement. Incidence and a method of classification. J Bone Joint Surg Am 55(8):1629\u0026ndash;1632\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaplan EL, Meier P (1958) Nonparametric estimation from incomplete observations. J Am Stat Assoc 53(282):457\u0026ndash;481\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eClohisy JC, Oryhon JM, Seyler TM, Wells CW, Liu SS, Callaghan JJ, Mont MA (2010) Function and fixation of total hip arthroplasty in patients 25 years of age or younger. Clin Orthop Relat Res 468(12):3207\u0026ndash;3213\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBourne RB, Rorabeck CH, Ghazal ME, Lee MH (1994) Pain in the thigh following total hip replacement with a porous-coated anatomic prosthesis for osteoarthrosis. A five-year follow-up study. J Bone Joint Surg Am 76(10):1464\u0026ndash;1470\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD`Ambrosi R, Marciandi L, Frediani PV, Facchini RM (2016) Uncemented total hip arthroplasty in patients younger than 20 years. J Orthop Sci 21(4):500\u0026ndash;506\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFinkbone PR, Severson EP, Cabanela ME, Trousdale RT (2012) Ceramic-on-ceramic total hip arthroplasty in patients younger than 20 years. J Arthroplasty 27(2):213\u0026ndash;219\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAdelani MA, Keeney JA, Palisch A, Fowler SA, Clohisy JC (2013) Has total hip arthroplasty in patients 30 years or younger improved? A Systematic Review. Clin Orthop Relat Res 471(8):2595\u0026ndash;2601\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H (2002) Cementless total hip arthroplasty with a close proximal fit and short tapered distal stem (third-generation) prosthesis. J Arthroplasty 17(7):841\u0026ndash;850\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim Y-H (2008) The results of a proximally-coated cementless femoral component in total hip replacement: a five-to 12-year follow-up. J Bone Joint Surg Br 90(3):299\u0026ndash;305\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBierbaum BE, Nairus J, Kuesis D, Morrison JC, Ward D (2002) Ceramic-on-ceramic bearings in total hip arthroplasty. Clin Orhtop Relat Res (405): 158\u0026ndash;163\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYoo JJ, Kim YM, Yoon KS, Koo KH, Song WS, Kim HJ (2005) Alumina-on-alumina total hip arthroplasty. A five-year minimum follow-up study. J Bone Joint Surg Am 87(3):530\u0026ndash;535\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eB\u0026ouml;rlin N, Thien T, K\u0026auml;rrholm J (2002) The precision of radiostereometric measurements. J Biomech 35(1):69\u0026ndash;79\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 4 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Clinical results, bone remodeling, calcar loading, lateral flare, anatomic, femoral stem","lastPublishedDoi":"10.21203/rs.3.rs-6043438/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6043438/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction\u003c/h2\u003e \u003cp\u003eThe purpose of this study was to evaluate the long-term clinical results (minimum 20 years) the ultra-short anatomic cementless stem in patients\u0026thinsp;\u0026lt;\u0026thinsp;50 years of age.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e \u003cp\u003eWe reviewed the 336 patients (421 hips) who had a cementless total hip arthroplasty (THA) in patients\u0026thinsp;\u0026lt;\u0026thinsp;50 years (46\u0026thinsp;\u0026plusmn;\u0026thinsp;3 years) at the time of surgery. The most common diagnoses were osteonecrosis (47%) and developmental dysplasia (37%). Demographic data, the Harris hip score, Western Ontario and McMaster Universities Osteoarthritic Index (WOMAC), and the University of California, Los Angeles (UCLA) activity scores were recorded. The minimum follow-up interval was 20 years (mean, 21.5 years; range, 20 to 24 years).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eAt the time of final follow-up, the mean Harris hip score, WOMAC score, and UCLA activity score were 93 points, 15 points, and 8 points, respectively. All but 7 patients had no thigh pain at the final follow-up. Seven hips (1.7%) had aseptic loosening of the stem. Survival rate at 24 years after the operation was 99.1% for the acetabular component and 96.4% for the femoral component.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThese results in patients\u0026thinsp;\u0026lt;\u0026thinsp;50 years of age suggest that this calcar loading with lateral flare anatomic cementless hip prosthesis provides good long-term fixation. Moreover, the alumina ceramic-on-alumina ceramic bearing provides a high rate of survivorship without osteolysis.\u003c/p\u003e","manuscriptTitle":"Long-Term Clinical Results of Calcar Loading with Lateral Flare Anatomic Cementless Stem in Patients Younger Than 50 Years","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-27 04:51:40","doi":"10.21203/rs.3.rs-6043438/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"af6c7c98-a22d-4d26-8dd2-b89abeaa814b","owner":[],"postedDate":"February 27th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-27T04:59:43+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-27 04:51:40","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6043438","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6043438","identity":"rs-6043438","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}