The Journal of Bone & Joint Surgery

The Journal of Bone & Joint Surgery, Volume 93, Issue 12

Scientific Articles | June 15, 2011

Quantitative Computed Tomography-Assisted Osteodensitometry of the Pelvis After Press-Fit Cup Fixation: A Prospective Ten-Year Follow-up

Alexander M. Kress, MD¹; Rainer Schmidt, MD, PhD¹; Tobias Vogel, MD¹; Tobias E. Nowak, MD²; Raimund Forst, MD, PhD¹; Lutz A. Mueller, MD, PhD¹

¹ Department of Orthopaedic Surgery, Friedrich-Alexander-University of Erlangen-Nuremberg, Rathsberger Strasse 57, D-91054 Erlangen, Germany. E-mail address for L.A. Mueller: ltzmll@aol.com
² Department of Trauma Surgery, Johannes-Gutenberg-University, Langenbeckstrasse 1, D-55131 Mainz, Germany

View Disclosures and Other Information

Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.

Investigation performed at the Department of Orthopaedic Surgery, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen, Germany

J Bone Joint Surg Am, 2011 Jun 15;93(12):1152-1157. doi: 10.2106/JBJS.J.01097

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Abstract

Background:

As a follow-up of a previously reported three-year study, we analyzed the periprosthetic acetabular cortical and cancellous bone density changes at ten years after implantation of a press-fit cup.

Methods:

Prospective clinical, radiographic, and quantitative computed tomography examinations were performed within ten days and at mean periods of one, three, and ten years after total hip arthroplasty with a press-fit cup, a femoral stem with a tapered design, and alumina-alumina pairing. Periacetabular cortical and cancellous bone density (mg CaHA/mL) in the cranial, ventral, and dorsal regions about the cup were measured for twenty-four hips in vivo.

Results:

All acetabular cups showed radiographic signs of stable ingrowth, and no acetabular component had to be revised. The loss of periacetabular cancellous bone density about the cup was as much as —37% cranially, —60% ventrally, and —71% dorsally; the decrease was progressive between the one-year and three-year examinations only. In contrast, cortical bone density above the dome of the acetabular cup remained constant throughout the ten-year follow-up. A moderate change in cortical bone density of —5% to —18% was seen at the level of the cup ten years postoperatively.

Conclusions:

Both periacetabular cortical and cancellous bone density changes were nonprogressive between the three-year and ten-year examinations after press-fit cup fixation.

Clinical Relevance:

Ten years postoperatively, the measured periacetabular cortical and cancellous bone density changes had no influence on the good clinical and radiographic performance of the cup.

Figures in this Article

Introduction

The remodeling pattern of periprosthetic bone after total hip arthroplasty is of major interest to basic-science researchers as reflected by numerous publications on finite element models^1-5. The clinical implication of these results is unclear as the natural long-term cause of periacetabular cancellous and cortical bone density changes has never been investigated^1-5. Dual x-ray absorptiometry studies^6-8 have shown substantial loss of pelvic bone density during the first six and twelve months after total hip arthroplasty with use of press-fit cups^6,8.

None of the above-mentioned studies or the numerous other dual x-ray absorptiometry^9-13 and finite element studies^1,2,14,15 on femoral bone density changes have been able to demonstrate any evidence-based clinical relevance of their results, and it thus remains unknown whether bone density loss compromises the longevity of a total hip replacement.

As the elastic modulus of metal-backed cups used for young and active patients is greater than the surrounding acetabular bone, stress-shielding and the periprosthetic bone resorption phenomena may, in theory, be clinically relevant for high-demand patients with long-term functional expectations^6,16,17.

In previous studies, we reported one-year and three-year quantitative computed tomography (CT) data on periprosthetic bone-density changes after total hip arthroplasty. We found a marked progressive cortical and cancellous bone density decrease in all regions of interest except for cortical bone adjacent to the dome of the cup^18,19.

On the basis of previous findings, we hypothesized there would be further substantial loss of periacetabular cancellous bone density between the three-year and ten-year follow-up evaluations and that cortical bone density changes cranial to the cup would be nonprogressive.

Materials and Methods

We recruited twenty-six consecutive patients (twenty-six hips) with degenerative hip disease who had been admitted for total hip arthroplasty. The one-year and three-year results of this group were reported previously^18,19. For this prospective study, all patients had follow-up quantitative CT examinations. Using a two-sided 95% confidence interval, we found that a comparative study with a sample size of twenty patients would have an 80% power to detect a 5% difference between serial quantitative CT measurements.

Concerning our exclusion criteria, we refer to our published three-year follow-up results¹⁸. Of the twenty-six patients, twenty-four (twenty-four hips) had postoperative one-year, three-year, and ten-year follow-up quantitative CT data sets for densitometry analysis. Two patients were excluded from the study (one patient had incomplete quantitative CT data sets, and one patient was lost to follow-up). The average age of the patients at the index operation was fifty-nine years (range, thirty-nine to seventy-seven years). There were nine women and fifteen men. The study was approved by the local ethics committee. Informed consent was obtained from all patients.

The Cerafit cup (Cerafit Triradius; Ceraver Osteal, Paris, France) is a fiber-mesh, metal-backed press-fit cup (52 to 60 mm in diameter) made of titanium alloy (Ti6Al7Nb; 3-mm thickness) with a flattened dome and a narrow equatorial rim with a matte surface finish. The cup is coated with hydroxyapatite (Ca₃[PO₄]₂). An alumina (Al₂O₃) ceramic liner and an uncemented, rough blasted, triple-taper hydroxyapatite (Ca₅[PO₄]₃[OH])-coated titanium alloy (Ti6Al7Nb) femoral stem with a 32-mm-diameter alumina (Al₂O₃) ceramic head was used in all hips. For specifications of the surgical and postoperative procedures, we refer to our prior publication¹⁸.

We obtained Harris hip scores²⁰ and administered the Oxford patient questionnaire²¹ (preoperatively and at one, three, and ten years postoperatively). Serial anteroposterior and lateral radiographs of the hip were made preoperatively and at the time of clinical follow-up. Definite radiographic loosening of the acetabular component was analyzed according to the method of Hodgkinson et al.²².

Computed tomography scans were made within the first ten days after total hip arthroplasty and subsequently at the one-year, three-year, and ten-year follow-up examinations. The protocol for CT scans has been described previously¹⁸.

Three of the six axial scans were performed above the cup; three scans were performed at the level of the cup (Fig. 1). An analysis of the ventral and dorsal regions of the retroacetabular area was performed by dividing the scan images through a coronal line passing across the center of the ceramic head of the stem (Fig. 2). The noninvolved, contralateral side was used as a control.

Fig. 1

Six CT scans of areas around the press-fit cup were used for the assessment of bone density; three were cranial, and three were on the level of the cup (horizontal lines). The axial images at the level of the cup were divided into ventral and dorsal by a coronal line crossing the center of the ceramic head of the femoral stem.

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Fig. 2

Two CT scans showing the bone density ventral and dorsal to the press-fit cup (a) and cranial to the implant (b). The dedicated quantitative CT software allows the separate assessment of cortical and cancellous bone with minimal artifact.

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To more easily interpret our data, we created three regions of interest (ROI), ventral, dorsal, and cranial to the cup, by calculating cortical and cancellous bone density (BD) values of the area (in square millimeters) of each scan under consideration according to the following expression¹⁸:{\mathop{\rm BD}\nolimits} \,{\rm of\,ROI} = {{({\mathop{\rm a}\nolimits} _1 \cdot {\mathop{\rm BD}\nolimits} _1) + ({\mathop{\rm a}\nolimits} _2 \cdot {\mathop{\rm BD}\nolimits} _2) + ({\mathop{\rm a}\nolimits} _3 \cdot {\mathop{\rm BD}\nolimits} _3)} \over {{\mathop{\rm a}\nolimits} _1 + {\mathop{\rm a}\nolimits} _2 + {\mathop{\rm a}\nolimits} _3 }}

where a = area (mm²) of the respective ROI for CT scans 1, 2, and 3, and BD = bone density (mg CaHA/mL) of the respective ROI for CT scans 1, 2, and 3.

An extended CT scale was used to reduce metal artifacts and to allow better delineation of the prosthesis-bone interface²³. The evaluation of data was performed with a specialized software tool (CAPPA postOP; CAS Innovations, Erlangen, Germany) and a calibration phantom for both the involved and the noninvolved side^18,24.

The relative change in periprosthetic bone density was measured as a function of time with the initial postoperative bone density value as the baseline value²⁵.

Statistical Analysis

We describe the quantitative bone density measurements as the mean values and standard deviations. The target measurement was the intra-individual difference between the ten-day postoperative measurement and the one-year, three-year, and ten-year evaluations. The comparison of paired data with non-normally distributed differences was made with use of the Wilcoxon signed-rank test. A p value of ≤0.05 was considered significant. All calculations were made with use of SPSS (version 10; SPSS, Chicago, Illinois).

Source of Funding

There was no external funding for this study.

Results

The mean Harris hip score was 44 points (range, 23 to 55 points) before the index operation and 94 points (range, 32 to 98 points) at the ten-year follow-up. Twenty-two hips (92%) were rated as good or excellent, two (8%) were rated as fair, and none was rated as poor. All hips were radiographically stable at the ten-year follow-up; all acetabular cups showed radiographic signs of osteointegration²⁰. No hip required revision surgery.

For all twenty-four acetabular components inserted without cement, fixation was good without a change in position on radiographs at a mean of 10.5 years (range, 10.1 to 11.4 years) of follow-up. Mean lateral inclination was 35° (range, 25° to 48°) at two weeks postoperatively and 35° (range, 25° to 47°) at the time of ten-year follow-up. Three cups had zone-II gaps with initial radiolucencies at two weeks postoperatively; two had closed the gap at the ten-year follow-up, and one had a nonprogressive zone-II radiolucency. No osteolysis was detected on radiographs.

We observed a substantial decrease of cancellous bone density in all regions of interest adjacent to the cup, whereas cortical bone density changes were minimal cranial to the cup. The mean change in cancellous bone density about the cup was −33% (range, −28% to −37%) cranially, −38% (range, −2% to −60%) ventrally, and −32% (range, −16% to −71%) dorsally at the time of the ten-year follow-up. The mean cortical bone density showed little change cranial to the cup (−2%; range, 0% to −15%), while the mean change was −16% (range, −15% to −18%) ventral and −13% (range, −5% to −18%) dorsal to the cup at the time of the ten-year follow-up (Fig. 3; see Appendix).

Fig. 3

The average percentage changes of the cortical and cancellous bone density (BD) under consideration in each area (in square millimeters) at one, three, and ten years after total hip arthroplasty¹⁸. ROI = region of interest.

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Bone density changes were highest between the ten-day and one-year control, moderate between the one-year and three-year follow-up examination, and minimal between the three-year and ten-year evaluation: cancellous bone density loss was progressive between the one-year and three-year postoperative evaluation cranial and dorsal to the cup. Between the three-year and ten-year evaluation, cancellous bone density values remained constant cranial and ventral to the cup and even slightly increased dorsal to the cup. Cortical bone density cranial and ventral to the cup slightly decreased between the three-year and ten-year follow-up, while little change was observed dorsal to the cup (Fig. 3; see Appendix).

On the noninvolved side, the mean change in cortical bone density was −3% (range, −1% to −6%) and the mean change in cancellous bone density was −6% (range, −4% to −12%) at the time of the ten-year follow-up. The mean changes of cortical and cancellous bone density of the noninvolved side were not significant.

As no cup showed radiographic signs of loosening and the clinical outcome was rated as good or excellent for all patients, a statistical analysis of the effect that bone density changes might have on the clinical or radiographic outcome was not done.

Discussion

Little is known about the in vivo load transfer of periprosthetic cortical and cancellous bone after press-fit acetabular cup insertion^18,19,26. In vitro analysis suggests a correlation between bone density changes and mechanical loading of the bone^27-29. Studying the current literature, we expected the insertion of a press-fit cup to alter the physiological stress transfer at the ilium, thus leading to marked bone density changes of certain anatomic areas and structures of the pelvis^{18,19,26,29,30}. Specifically, we expected to find substantial loss of periacetabular cancellous bone density and an increase in cortical bone density cranial to the cup. We anticipated the cancellous bone density loss to be progressive after the third postoperative year^8,18,31 and to perhaps compromise the longevity of the implant.

Our results confirmed some, but not all, of our hypotheses. First, we found no marked decrease in cancellous bone density in any areas surrounding the cup between the three-year and ten-year follow-up. The clinical and radiographic results and the longevity of the implant were not compromised. Second, although cortical bone density slightly decreased cranial to the cup between the three-year and the ten-year analysis, a homeostatic strain configuration was seen in this area as no significant cortical bone density changes were observed in that region at the ten-year follow-up.

The low bone density decrease on the noninvolved side might be attributed to the high activity level of the study group (the patients had an average age of sixty-nine years and an average Harris hip score of 94 points at the time of the ten-year follow-up) as well as to the fact that we investigated the bone density changes of fifteen men and only nine women.

High radiation exposure and time-consuming manual segmentation of cortical and cancellous bone are the major limitations of quantitative CT osteodensitometry. Nonetheless, quantitative CT is suitable for repeated longitudinal measurements in clinical research studies. The effective dose of radiation received during one periacetabular quantitative CT examination is 0.8 to 1.6 mSv, approximately 30% to 60% of the natural yearly radiation exposure in Central Europe^23,32. Exposure to serial quantitative CT with twelve-month intervals has been considered acceptable by our local ethics committee who approved osteodensitometry studies²⁶.

Quantitative CT-assisted osteodensitometry and dual x-ray absorptiometry are sensitive and precise tools for detecting changes in periprosthetic bone density^33-36. Measurement of the changes in bone density after the surgical procedure provides a good indication of the pattern of load transfer between implant and host bone⁴. However, in the pelvic region, dual x-ray absorptiometry is limited by low resolution and the lack of three-dimensional information⁷. Computed tomography is a standardized imaging method for assessment of bone structures with high validity and resolution, which also allows separation of cortical and cancellous bone structures^19,36,37. Thus far, both dual x-ray absorptiometry and quantitative CT-assisted osteodensitometry studies have lacked clinical relevance, as they have been unable to predict early failure of the prostheses before it is imminent clinically or radiographically^8,19,26,31.

Some finite element analyses have suggested major changes in acetabular load transmission pattern after uncemented total hip arthroplasty^3,4, while others have noted little change in bone density of the ilium after simulated press-fit cup fixation⁵. Recent finite element studies have pointed out that the simulation results are highly dependent on the chosen boundary conditions and on a differentiation between the elastic properties for cancellous and cortical bone^1,2,14. Nevertheless, to date, computational bone-remodeling simulations have primarily been compared with dual x-ray absorptiometry results, a method that lacks the ability to differentiate between cortical and cancellous bone^1,2,4,14,38. Long-term quantitative CT-assisted osteodensitometry studies are necessary to calibrate the bone adaptation laws for cortical and cancellous bone density changes and thus validate the finite element calculations, which may then generate accurate patient-specific meshes for simulation of acetabular components and their effect on pelvic bone remodeling^39,40. This technology would be useful for a radiation-free prediction of bone remodeling and quality of implant fixation with use of prostheses with different designs and biomaterials. In the future, this tool could be applied for preclinical validation of new implants before their widespread use³⁵. As the Cerafit cup is a made of a 3-mm-thick metal-backed titanium alloy, we believe that the measured bone density changes are independent of the used pairing.

In all of our patients, the cups had radiographic signs of osseous ingrowth at the time of the ten-year follow-up, no osteolysis or progressive radiolucent lines were detected, and the clinical results were good or excellent. Our data present the natural course of periacetabular cortical and cancellous bone density changes over a ten-year follow-up period for well-fitting hydroxyapatite-coated, fiber-mesh press-fit components. Even cancellous bone density loss of as much as —71% and a cortical bone density loss of as much as —18% at the time of the ten-year follow-up appear not to be concerning in relation to the survival of the implants, and this finding needs to be considered for all bone density studies suggesting the use of bone-modulating drugs to enhance the longevity of total hip replacement⁸.

To our knowledge, this study is the first prospective long-term observation of periacetabular cortical and cancellous bone density changes after fixation of a press-fit acetabular cup. Nevertheless, the number of patients included in this study is too small to allow evidence-based conclusions as to whether the described bone density losses play or will play any clinically relevant role. Only future studies with much larger patient cohorts might clarify whether cortical and cancellous periacetabular bone density loss will compromise implant longevity and especially whether the observed substantial loss of cancellous bone density is one of several concurrent factors predisposing to osteolysis adjacent to the implants.

Appendix

A table showing postoperative and follow-up mean cancellous and cortical bone density measurements and pairwise difference is available with the online version of this article at jbjs.org.

References

Jonkers I; Sauwen N; Lenaerts G; Mulier M; Van der Perre G; Jaecques S. Relation between subject-specific hip joint loading, stress distribution in the proximal femur and bone mineral density changes after total hip replacement. J Biomech. 2008;41:3405-13.[CrossRef][PubMed]

Behrens BA; Nolte I; Wefstaedt P; Stukenborg-Colsman C; Bouguecha A. Numerical investigations on the strain-adaptive bone remodelling in the periprosthetic femur: influence of the boundary conditions. Biomed Eng Online. 2009;8:7.[CrossRef][PubMed]

Huiskes R; Weinans H; Dalstra M. Adaptive bone remodeling and biomechanical design considerations for noncemented total hip arthroplasty. Orthopedics. 1989;12:1255-67.[PubMed]

Kerner J; Huiskes R; van Lenthe GH; Weinans H; van Rietbergen B; Engh CA; Amis AA. Correlation between pre-operative periprosthetic bone density and post-operative bone loss in THA can be explained by strain-adaptive remodelling. J Biomech. 1999;32:695-703.[CrossRef][PubMed]

Levenston ME; Beaupré GS; Schurman DJ; Carter DR. Computer simulations of stress-related bone remodeling around noncemented acetabular components. J Arthroplasty. 1993;8:595-605.[CrossRef][PubMed]

Digas G; Kärrholm J; Thanner J. Different loss of BMD using uncemented press-fit and whole polyethylene cups fixed with cement: repeated DXA studies in 96 hips randomized to 3 types of fixation. Acta Orthop. 2006;77:218-26.[CrossRef][PubMed]

Shetty NR; Hamer AJ; Kerry RM; Stockley I; Eastell R; Wilkinson JM. Bone remodelling around a cemented polyethylene cup. A longitudinal densitometry study. J Bone Joint Surg Br. 2006;88:455-9.[PubMed]

Wilkinson JM; Eagleton AC; Stockley I; Peel NF; Hamer AJ; Eastell R. Effect of pamidronate on bone turnover and implant migration after total hip arthroplasty: a randomized trial. J Orthop Res. 2005;23:1-8.[CrossRef][PubMed]

Albanese CV; Santori FS; Pavan L; Learmonth ID; Passariello R. Periprosthetic DXA after total hip arthroplasty with short vs. ultra-short custom-made femoral stems: 37 patients followed for 3 years. Acta Orthop. 2009;80:291-7.[CrossRef][PubMed]

Alm JJ; Mäkinen TJ; Lankinen P; Moritz N; Vahlberg T; Aro HT. Female patients with low systemic BMD are prone to bone loss in Gruen zone 7 after cementless total hip arthroplasty. Acta Orthop. 2009;80:531-7.[CrossRef][PubMed]

Grochola LF; Habermann B; Mastrodomenico N; Kurth A. Comparison of periprosthetic bone remodelling after implantation of anatomic and straight stem prostheses in total hip arthroplasty. Arch Orthop Trauma Surg. 2008;128:383-92.[CrossRef][PubMed]

Glassman AH; Bobyn JD; Tanzer M. New femoral designs: do they influence stress shielding?Clin Orthop Relat Res. 2006;453:64-74.[CrossRef][PubMed]

Hayaishi Y; Miki H; Nishii T; Hananouchi T; Yoshikawa H; Sugano N. Proximal femoral bone mineral density after resurfacing total hip arthroplasty and after standard stem-type cementless total hip arthroplasty, both having similar neck preservation and the same articulation type. J Arthroplasty. 2007;22:1208-13.[CrossRef][PubMed]

Turner AW; Gillies RM; Sekel R; Morris P; Bruce W; Walsh WR. Computational bone remodelling simulations and comparisons with DEXA results. J Orthop Res. 2005;23:705-12.[CrossRef][PubMed]

Taylor M; Tanner KE; Freeman MA; Yettram AL. Finite element modelling—predictor of implant survival?J Mater Sci. 1995;6:808-12.[CrossRef]

Bizot P; Hannouche D; Nizard R; Witvoet J; Sedel L. Hybrid alumina total hip arthroplasty using a press-fit metal-backed socket in patients younger than 55 years. A six- to 11-year evaluation. J Bone Joint Surg Br. 2004;86:190-4.[CrossRef][PubMed]

Currey JD. The effect of porosity and mineral content on the Young's modulus of elasticity of compact bone. J Biomech. 1988;21:131-9.[CrossRef][PubMed]

Mueller LA; Voelk M; Kress A; Pitto RP; Schmidt R. An ABJS Best Paper: Progressive cancellous and cortical bone remodeling after press-fit cup fixation: a 3-year followup. Clin Orthop Relat Res. 2007;463:213-20.[PubMed]

Mueller LA; Nowak TE; Mueller LP; Schmidt R; Ehrmann C; Pitto RP; Pfander D; Forst R; Eichinger S. Acetabular cortical and cancellous bone density and radiolucent lines after cemented total hip arthroplasty: a prospective study using computed tomography and plain radiography. Arch Orthop Trauma Surg. 2007;127:909-17.[CrossRef][PubMed]

Harris WH. 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. 1969;51:737-55.[PubMed]

Dawson J; Fitzpatrick R; Carr A; Murray D. Questionnaire on the perceptions of patients about total hip replacement. J Bone Joint Surg Br. 1996;78:185-90.[PubMed]

Hodgkinson JP; Shelley P; Wroblewski BM. The correlation between the roentgenographic appearance and operative findings at the bone-cement junction of the socket in Charnley low friction arthroplasties. Clin Orthop Relat Res. 1988;228:105-9.[PubMed]

Kalender WA. A phantom for standardization and quality control in spinal bone mineral measurements by QCT and DXA: design considerations and specifications. Med Phys. 1992;19:583-6.[CrossRef][PubMed]

Schmidt R; Muller L; Kress A; Hirschfelder H; Aplas A; Pitto RP. A computed tomography assessment of femoral and acetabular bone changes after total hip arthroplasty. Int Orthop. 2002;26:299-302.[CrossRef][PubMed]

Schmidt R; Pitto RP; Kress A; Ehremann C; Nowak TE; Reulbach U; Forst R; Müller L. Inter- and intraobserver assessment of periacetabular osteodensitometry after cemented and uncemented total hip arthroplasty using computed tomography. Arch Orthop Trauma Surg. 2005;125:291-7.[CrossRef][PubMed]

Mueller LA; Kress A; Nowak T; Pfander D; Pitto RP; Forst R; Schmidt R. Periacetabular bone changes after uncemented total hip arthroplasty evaluated by quantitative computed tomography. Acta Orthop. 2006;77:380-5.[CrossRef][PubMed]

Krischak GD; Augat P; Wachter NJ; Kinzl L; Claes LE. Predictive value of bone mineral density and Singh index for the in vitro mechanical properties of cancellous bone in the femoral head. Clin Biomech (Bristol, Avon). 1999;14:346-51.[CrossRef][PubMed]

Krischak GD; Wachter NJ; Zabel T; Suger G; Beck A; Kinzl L; Claes LE; Augat P. Influence of preoperative mechanical bone quality and bone mineral density on aseptic loosening of total hip arthroplasty after seven years. Clin Biomech (Bristol, Avon). 2003;18:916-23.[CrossRef][PubMed]

Wachter NJ; Krischak GD; Mentzel M; Sarkar MR; Ebinger T; Kinzl L; Claes L; Augat P. Correlation of bone mineral density with strength and microstructural parameters of cortical bone in vitro. Bone. 2002;31:90-5.[CrossRef][PubMed]

Vasu R; Carter DR; Harris WH. Stress distributions in the acetabular region—I. Before and after total joint replacement. J Biomech. 1982;15:155-64.[CrossRef][PubMed]

Sabo D; Reiter A; Simank HG; Thomsen M; Lukoschek M; Ewerbeck V. Periprosthetic mineralization around cementless total hip endoprosthesis: longitudinal study and cross-sectional study on titanium threaded acetabular cup and cementless Spotorno stem with DEXA. Calcif Tissue Int. 1998;62:177-82.[CrossRef][PubMed]

Kalender WA. Effective dose values in bone mineral measurements by photon absorptiometry and computed tomography. Osteoporos Int. 1992;2:82-7.[CrossRef][PubMed]

Kröger H; Venesmaa P; Jurvelin J; Miettinen H; Suomalainen O; Alhava E. Bone density at the proximal femur after total hip arthroplasty. Clin Orthop Relat Res. 1998;352:66-74.[PubMed][CrossRef]

Mirsky EC; Einhorn TA. Bone densitometry in orthopaedic practice. J Bone Joint Surg Am. 1998;80:1687-98.[PubMed]

Pitto RP; Mueller LA; Reilly K; Schmidt R; Munro J. Quantitative computer-assisted osteodensitometry in total hip arthroplasty. Int Orthop. 2007;31:431-8.[CrossRef][PubMed]

Schmidt R; Nowak TE; Mueller L; Pitto RP. Osteodensitometry after total hip replacement with uncemented taper-design stem. Int Orthop. 2004;28:74-7.[CrossRef][PubMed]

Houde J; Marchetti M; Duquette J; Hoffman A; Steinberg G; Crane GK; Baran D. Correlation of bone mineral density and femoral neck hardness in bovine and human samples. Calcif Tissue Int. 1995;57:201-5.[CrossRef][PubMed]

Bitsakos C; Kerner J; Fisher I; Amis AA. The effect of muscle loading on the simulation of bone remodelling in the proximal femur. J Biomech. 2005;38:133-9.[PubMed][CrossRef]

Shim VB; Pitto RP; Streicher RM; Hunter PJ; Anderson IA. The use of sparse CT datasets for auto-generating accurate FE models of the femur and pelvis. J Biomech. 2007;40:26-35.[CrossRef][PubMed]

Viceconti M; Davinelli M; Taddei F; Cappello A. Automatic generation of accurate subject-specific bone finite element models to be used in clinical studies. J Biomech. 2004;37:1597-605.[CrossRef][PubMed]

Topics

bone mineral density ; cranium ; hip replacement arthroplasty ; pelvis ; compact bone ; trabecular bone ; component fixation, press-fit

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Alexander M. Kress, Rainer Schmidt, Tobias Vogel, Tobias E. Nowak, Raimund Forst, Lutz A. Mueller; Quantitative Computed Tomography-Assisted Osteodensitometry of the Pelvis After Press-Fit Cup FixationA Prospective Ten-Year Follow-up. The Journal of Bone & Joint Surgery. 2011 Jun;93(12):1152-1157.

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