451
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Matsushita A, Nakashima Y, Fujii M, Sato T, Iwamoto Y. Modular necks improve the range of hip motion in cases with excessively anteverted or retroverted femurs in THA. Clin Orthop Relat Res 2010; 468:3342-7. [PMID: 20473596 PMCID: PMC2974865 DOI: 10.1007/s11999-010-1385-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 04/29/2010] [Indexed: 01/31/2023]
Abstract
BACKGROUND Anteversion of an acetabular component often is difficult to ascertain in patients with THA in whom excessively anteverted or retroverted femurs may result in limited ROM or risk of dislocation. Restriction of motion, however, is determined by the combination of version of both components. QUESTIONS/PURPOSES We therefore determined the combined anteversion values that provide adequate ROM. We varied acetabular version by differing implantations and varied femoral version with modular necks. METHODS ROM was tested by changing cup anteversion after setting the femoral version to 20° or 60° anteversion or 20° retroversion. The angle of the modular neck was adjusted in 11 increments of 5° each. Range of internal rotation (IR) at 90° flexion, external rotation (ER) at 0° extension, and flexion (Flex) were measured when any impingement occurred before dislocation. We defined a required ROM as having 40° IR, 30° ER, and 110° Flex. RESULTS At 60° anteversion, ER was less than 10° even when the acetabular component was set at 10° retroversion because of posterior impingement. When a modular neck with 25° retroversion was used, ER improved to greater than 30°. At 20° retroversion, IR was 31° even when the acetabular component was opened to 35° anteversion. IR improved to 34° and 40° with 20° and 25° anteverted modular necks, respectively. CONCLUSIONS AND CLINICAL RELEVANCE In cases with excessive femoral anteversion or retroversion, the required ROM could not be achieved by simply changing the version of acetabular components. The adjustment of femoral versions using the modular necks allowed additional improvement of ROM.
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Affiliation(s)
- Akinobu Matsushita
- Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
| | - Yasuharu Nakashima
- Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
| | - Masanori Fujii
- Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
| | - Taishi Sato
- Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
| | - Yukihide Iwamoto
- Department of Orthopedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan
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452
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Hirasawa N, Matsubara M, Ishii K, Hagio S, Okuda N, Sekiya I, Muneta T. Effect of CT slice thickness on accuracy of implant positioning in navigated total hip arthroplasty. ACTA ACUST UNITED AC 2010; 15:83-9. [DOI: 10.3109/10929088.2010.525025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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453
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Tsukada S, Wakui M. Decreased accuracy of acetabular cup placement for imageless navigation in obese patients. J Orthop Sci 2010; 15:758-63. [PMID: 21116893 DOI: 10.1007/s00776-010-1546-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 08/11/2010] [Indexed: 11/25/2022]
Abstract
BACKGROUND Optimal acetabular cup position is an important determinant of the success of total hip arthroplasty (THA), and navigation systems have been developed and applied to improve placement precision. However, the registration method touching bony landmarks through soft tissues may decrease the accuracy in obese cases and in patients with acetabular dysplasia. METHODS Placement accuracy in 69 joints in which THA was performed with imageless navigation was calculated by comparing the placement angle in the anterior pelvic plane and the placement angle in the x-ray table plane with the patient in the supine position. We defined the difference between the placement angle in the anterior pelvic plane and the angle displayed on the navigation screen as the error and the difference between the placement angle in the plane of the x-ray table and the target angle of acetabular component position as the difference in target angle. Patients were divided into obese (BMI ≥ 25) and nonobese (BMI < 25) groups and into acetabular dysplasia and nondysplasia groups. RESULTS The mean ± SD navigation errors for all cases were 2.4° ± 2.0° for inclination and 3.7° ± 2.3° for anteversion. The mean difference in target angle for all cases was 2.8° ± 2.5° for inclination and 4.2° ± 3.0° for anteversion. The error in anteversion was significantly higher in the obese group (4.8° ± 2.5°) than in the nonobese group (3.2° ± 2.6°) (P = 0.01). No significant difference was observed between the acetabular dysplasia and nondysplasia groups. CONCLUSIONS Imageless navigation can be performed with an error of approximately 3° at the anterior pelvic plane. However, accuracy was found to decrease in obese cases.
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Affiliation(s)
- Sachiyuki Tsukada
- Department of Orthopaedic Surgery, Niigata Central Hospital, 1-18 Shinko-chou, Chuo-ku, Niigata 950-8556, Japan
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454
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Wassilew GI, Perka C, Koenig C, Janz V, Asbach P, Hasart O. 3D CT analysis of combined cup and stem anteversion in cases of cup navigation in hip arthroplasty. Orthopedics 2010; 33:48-51. [PMID: 20954630 DOI: 10.3928/01477447-20100510-53] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Navigation of the cup in total hip arthroplasty is well analyzed and shows accurate results, reducing cup outliers of Lewinnek's "safe zone." With regard to the combined anteversion of cup and stem, however, a "new" safe zone with a range of 25° to 50° has been published. The aim of this study was to analyze total anteversion (cup and stem) by postoperative 3D computed tomography in isolated cup navigation cases. In 46 patients, the mean combined anteversion was 34.4° (range, 16.3°-57.3°, SD ± 9.3°) with 10 outliers. The mean cup anteversion was 19.5° (range, 11°-27°, SD ± 3.7°). Regarding Lewinnek's "safe zone" (cup only), we observed 5 outliers. An improvement of technique of stem implantation or navigation may reduce outliers of combined anteversion.
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Affiliation(s)
- Georgi I Wassilew
- Charité Orthopaedic Department, Center for Musculoskeletal Surgery, Charité, Charitéplatz 1, 10117, Berlin, Germany
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455
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Statistically Deformable 2D/3D Registration for Estimating Post-operative Cup Orientation from a Single Standard AP X-ray Radiograph. Ann Biomed Eng 2010; 38:2910-27. [DOI: 10.1007/s10439-010-0060-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
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456
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Müller M, Crucius D, Perka C, Tohtz S. The association between the sagittal femoral stem alignment and the resulting femoral head centre in total hip arthroplasty. INTERNATIONAL ORTHOPAEDICS 2010; 35:981-7. [PMID: 20549502 DOI: 10.1007/s00264-010-1047-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 05/04/2010] [Accepted: 05/09/2010] [Indexed: 01/21/2023]
Abstract
Adequate stem alignment is essential for the success of Total Hip Arthroplasty (THA) to avoid dislocation and impingement. One factor that has not been sufficiently investigated so far is the stem tilting in the sagittal plane, which has an influence on the position of the centre of the femoral head and thus also on prosthesis torsion. We aimed to evaluate sagittal stem position using 3D-CTs in patients with THA and to develop a mathematical-geometrical model to simulate the functional correlation between sagittal stem tilting and the influence on functional anteversion. Thirty patients with THA underwent a CT-scan. By 3D-reconstruction of the CT-data, femoral-/prosthesis-axis, torsion and sagittal tilt were determined. In accordance with the position of the femoral and prosthesis axes, the rotatory (rAV) (surgically adjusted) and functional (depending on sagittal tilt) anteversion (fAV) was measured. A three dimentional-coordinate transformation was also performed using the Euler-angles to derive a mathematical-geometrical correlation between sagittal stem tilting and corresponding influence on anteversion. The mean rAV was 8° (-11.6-26°), the fAV 18° (6.2-37°), and the difference 10° (8.8-18°). The mean degree of stem tilting was 5.2° (0.7-9°) anterior towards the femoral axis. The individually measured parameters are reflected in the mathematical-geometrical model. Depending on the extent of the sagittal deviation, a clear influence on the torsion emerges. For example, a stem implanted at a 15° anteverted angle with a sagittal tilt by two degrees towards anterior results in a fAV of 20°. A clear association between the sagittal stem alignment and the impact on the fAV was demonstrated. Hence, the rotatory anteversion intended by the surgeon may be functionally significantly different. This might pose an increased risk of dislocation or impingement. The sagittal tilt of the prosthesis should therefore be considered in the context of impingement and dislocation diagnosis. In this respect, we recommend a 3D-analysis of stem alignment.
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Affiliation(s)
- Michael Müller
- Department of Orthopaedics, Charité-University Medicine, Berlin, Germany.
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457
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Kurtz WB, Ecker TM, Reichmann WM, Murphy SB. Factors affecting bony impingement in hip arthroplasty. J Arthroplasty 2010; 25:624-34.e1-2. [PMID: 19559561 DOI: 10.1016/j.arth.2009.03.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 03/28/2009] [Indexed: 02/01/2023] Open
Abstract
Computer modeling of 10 patients' computed tomographic scans was used to study the variables affecting hip arthroplasty range of motion before bony impingement (ROMBI) including acetabular offset and height, femoral offset, height and anteversion, and osteophyte removal. The ROMBI was compared with the ROM before component impingement and the native hip ROM. The ROMBI decreased with decreased total offset and limb shortening. Acetabular offset and height had a greater effect on ROMBI than femoral offset and height. The ROMBI lost with decreased acetabular offset was not fully recoverable with an increase in femoral offset or osteophyte removal. Bony impingement increased and component impingement decreased with decreased acetabular offset and increased head diameter.
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458
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A three-dimensional parameterized and visually kinematic simulation module for the theoretical range of motion of total hip arthroplasty. Clin Biomech (Bristol, Avon) 2010; 25:427-32. [PMID: 20189695 DOI: 10.1016/j.clinbiomech.2010.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2009] [Revised: 01/20/2010] [Accepted: 01/21/2010] [Indexed: 02/07/2023]
Abstract
BACKGROUND Proper option and optimal alignment of implants are major factors in obtaining the desired range of motion of total hip arthroplasty. It would be very useful if a tool is available to assist clinicians to preoperatively determine proper implants and their optimal intraoperative alignment for individual patient. METHODS Based on the secondary development function of ADAMS/VIEW, a three-dimensional parameterized module was developed to simulate six motions of implants for total hip arthroplasty. Total eight parameters (stem abduction, acetabular size, head size, general head-neck ratio, stem-neck angle, acetabular anteversion, acetabular inclination and femoral antetorsion) were included and three definitions of acetabular orientations (operative, radiographic and anatomical) were available. Any initial position of implants and simulation precision could be defined on the demand. FINDINGS After entering these eight parameters, a special model of total hip arthroplasty would be constructed. Single or combined motion until the prosthetic impingement could be simulated visually and the corresponding maximal rotation angle would be quantified. INTERPRETATION Clinical factors, such as patients with severe deformity of hip joint or a large range of motion demand, should be considered during total hip arthroplasty. This module can provide references for clinicians on proper option and intraoperative implantation of components, and be suitable for postoperative evaluation. Furthermore, it is a tool to investigate the "safe-zones" of total hip arthroplasty and also can be employed for the design of new implant system.
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459
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Zheng G. Effective incorporating spatial information in a mutual information based 3D-2D registration of a CT volume to X-ray images. Comput Med Imaging Graph 2010; 34:553-62. [PMID: 20413268 DOI: 10.1016/j.compmedimag.2010.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 12/28/2009] [Accepted: 03/23/2010] [Indexed: 10/19/2022]
Abstract
This paper addresses the problem of estimating the 3D rigid poses of a CT volume of an object from its 2D X-ray projection(s). We use maximization of mutual information, an accurate similarity measure for multi-modal and mono-modal image registration tasks. However, it is known that the standard mutual information measures only take intensity values into account without considering spatial information and their robustness is questionable. In this paper, instead of directly maximizing mutual information, we propose to use a variational approximation derived from the Kullback-Leibler bound. Spatial information is then incorporated into this variational approximation using a Markov random field model. The newly derived similarity measure has a least-squares form and can be effectively minimized by a multi-resolution Levenberg-Marquardt optimizer. Experiments were conducted on datasets from two applications: (a) intra-operative patient pose estimation from a limited number (e.g. 2) of calibrated fluoroscopic images, and (b) post-operative cup orientation estimation from a single standard X-ray radiograph with/without gonadal shielding. The experiment on intra-operative patient pose estimation showed a mean target registration accuracy of 0.8mm and a capture range of 11.5mm, while the experiment on estimating the post-operative cup orientation from a single X-ray radiograph showed a mean accuracy below 2 degrees for both anteversion and inclination. More importantly, results from both experiments demonstrated that the newly derived similarity measures were robust to occlusions in the X-ray image(s).
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Affiliation(s)
- Guoyan Zheng
- Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, Bern, Switzerland.
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460
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Malviya A, Lingard EA, Malik A, Bowman R, Holland JP. Hip flexion after Birmingham hip resurfacing: role of cup anteversion, anterior femoral head-neck offset, and head-neck ratio. J Arthroplasty 2010; 25:387-91. [PMID: 19285379 DOI: 10.1016/j.arth.2009.01.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 11/12/2008] [Accepted: 01/25/2009] [Indexed: 02/01/2023] Open
Abstract
We aimed to investigate the factors affecting range of flexion after hip resurfacing. A total of 82 cases, operated by a single surgeon, were assessed at a mean of 43 months. The Einzel-Bild-Roentgen-Analysis for the acetabular cup software was used to measure socket orientation. Range of flexion had a moderate positive correlation with cup anteversion (R = 0.26, P = .017), weak but significant negative correlation with neck diameter (R = -0.23, P = .042), and none with anterior femoral head-neck offset. Using multivariate analysis that adjusted for age, sex, cup anteversion and inclination, head-neck offset ratio, head-neck ratio, and neck diameter, the only significant correlate of flexion was cup anteversion (P = .017). Care should be taken during cup placement to allow adequate anteversion to be maintained in Birmingham hip resurfacing because this can affect flexion range of motion.
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Affiliation(s)
- Ajay Malviya
- Department of Orthopaedics, Freeman Hospital, Newcastle upon Tyne, United Kingdom
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461
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Tailor-made Surgical Guide Reduces Incidence of Outliers of Cup Placement. Clin Orthop Relat Res 2010; 468:1088-95. [PMID: 19629605 PMCID: PMC2835612 DOI: 10.1007/s11999-009-0994-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 07/07/2009] [Indexed: 01/31/2023]
Abstract
UNLABELLED Malalignment of the cup in total hip arthroplasty (THA) increases the risks of postoperative complications such as neck cup impingement, dislocation, and wear. We asked whether a tailor-made surgical guide based on CT images would reduce the incidence of outliers beyond 10 degrees from preoperatively planned alignment of the cup compared with those without the surgical guide. We prospectively followed 38 patients (38 hips, Group 1) having primary THA with the conventional technique and 31 patients (31 hips, Group 2) using the surgical guide. We designed the guide for Group 2 based on CT images and fixed it to the acetabular edge with a Kirschner wire to indicate the planned cup direction. Postoperative CT images showed the guide reduced the number of outliers compared with the conventional method (Group 1, 23.7%; Group 2, 0%). The surgical guide provided more reliable cup insertion compared with conventional techniques. LEVEL OF EVIDENCE Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
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462
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Zheng G, Zhang X. Computer assisted determination of acetabular cup orientation using 2D–3D image registration. Int J Comput Assist Radiol Surg 2010; 5:437-47. [DOI: 10.1007/s11548-010-0407-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 02/03/2010] [Indexed: 11/28/2022]
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463
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Cinotti G, Lucioli N, Malagoli A, Calderoli C, Cassese F. Do large femoral heads reduce the risks of impingement in total hip arthroplasty with optimal and non-optimal cup positioning? INTERNATIONAL ORTHOPAEDICS 2010; 35:317-23. [PMID: 20157813 DOI: 10.1007/s00264-010-0954-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Revised: 01/06/2010] [Accepted: 01/06/2010] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to assess whether large femoral heads (36-38 mm) improve the range of motion in total hip arthroplasty compared to standard (28-32 mm) femoral heads in the presence of optimal and non-optimal cup positioning. A mathematical model of the hip joint was generated by using a laser scan of a dried cadaveric hip. The range of motion was assessed with a cup inclination and anteversion of reference and with non-optimal cup positions. Large femoral heads increased the range of motion, compared to the 28-mm femoral head, in the presence of a hip prosthesis correctly implanted and even more so in the presence of non-optimal cup positioning. However, with respect to the 32-mm femoral head, large femoral heads showed limited benefits both in the presence of optimal and non-optimal cup positioning.
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464
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Zhu J, Wan Z, Dorr LD. Quantification of pelvic tilt in total hip arthroplasty. Clin Orthop Relat Res 2010; 468:571-5. [PMID: 19714387 PMCID: PMC2806995 DOI: 10.1007/s11999-009-1064-7] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 08/14/2009] [Indexed: 01/31/2023]
Abstract
UNLABELLED In THA, anterior or posterior tilt of the pelvis changes the position of the acetabular component on the coronal plane of the body as compared with its anatomic position in the pelvic bone. To understand the occurrence and clinical importance for patients with pelvic tilt on an operating room table in the lateral decubitus position, we studied 436 patients (477 hips) undergoing primary THA using an imageless computer navigation system that measured tilt. We determined the distribution and magnitude of pelvic tilt, especially tilt of 10 degrees or greater. The distribution of tilt had a range of 25 degrees posterior to 20 degrees anterior. Twenty-nine of 477 (6.1%) hips had zero tilt; 251 (52.6%) had tilt of 1 degrees to 5 degrees; 120 (25.2%) had tilt of 6 degrees to 9 degrees; and 77 (16.1%) had tilt of 10 degrees or greater. The conversion factor for acetabular anteversion has been determined by a mathematical formula by Lembeck et al. and was confirmed by us in practice. Measurement of pelvic tilt during the performance of THA will improve the accuracy of cup position, especially allowing anteversion to be measured on the coronal plane. LEVEL OF EVIDENCE Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Jinjun Zhu
- The Arthritis Institute, 637 S Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Zhinian Wan
- The Arthritis Institute, 637 S Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Lawrence D. Dorr
- The Arthritis Institute, 637 S Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
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465
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Bargar WL, Jamali AA, Nejad AH. Femoral anteversion in THA and its lack of correlation with native acetabular anteversion. Clin Orthop Relat Res 2010; 468:527-32. [PMID: 19714389 PMCID: PMC2806998 DOI: 10.1007/s11999-009-1040-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Accepted: 07/29/2009] [Indexed: 01/31/2023]
Abstract
Several studies support the concept that, for optimum range of motion in THA, the combined femoral and acetabular anteversion should be some constant or fall within some "safe zone." When using a cementless femoral component, the surgeon has little control of the anteversion of the component since it is dictated by native femoral anteversion. Given this constraint, we asked whether the surgeon should use the native anteversion of the acetabulum as a target for implant position in THA. Forty-six patients scheduled for primary THA underwent CT scanning and preoperative planning using a computer workstation. The native acetabular anteversion and the native femoral anteversion were measured. Prosthetic femoral anteversion was measured on the workstation by three-dimensional templating of a straight-stemmed tapered implant. The mean of the sum of the native acetabular anteversion and native femoral anteversion was 28.9 degrees; however, 17% varied by 10 degrees to 15 degrees and 11% by more than 15 degrees. The mean of native femoral anteversion and prosthetic femoral anteversion was 13.8 degrees (range, -6.1 degrees-32.7 degrees) and 22.5 degrees (range, 1 degrees-39 degrees), respectively. Based on our data, we believe the surgeon should not use the native acetabular anteversion as a target for positioning the acetabular component.
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466
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Omlor GW, Ullrich H, Krahmer K, Jung A, Aldinger G, Aldinger P. A stature-specific concept for uncemented, primary total hip arthroplasty. Acta Orthop 2010; 81:126-33. [PMID: 20146639 PMCID: PMC2856217 DOI: 10.3109/17453671003587077] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND AND PURPOSE Variations in hip anatomy limit the femoral canal fit of standard uncemented hip stems. In addition, there are still issues with leg length discrepancy and offset reconstruction, potentially resulting in impingement, dislocation, and wear. Modular stems with different shapes for femoral canal fit and multiple neck options may improve the outcome and reduce complications. PATIENTS AND METHODS 173 patients (190 hips) received an uncemented THA with 1 of 2 different stem shapes for canal fit and a modular neck for stature-specific hip reconstruction. Median follow-up time was 9 (7-13) years. During the follow-up period, 20 patients died (22 hips) and 12 patients (13 hips) were lost to follow-up. 155 hips were available for evaluation, including clinical and radiological outcome. RESULTS 1 stem was revised for a periprosthetic fracture following trauma; 10 cups and 2 modular necks were revised (1 for breakage and 1 during cup revision). At 10 years, stem survival was 100%, modular neck survival was 99% (CI: 95-100), and cup survival was 94% (CI: 87-97). No leg length discrepancies were measured in 96% of cases. Offset with anatomic lateralization was achieved in 98%. Median Harris hip score was 94 (47-100) and median Merle d'Aubigné score was 16 (10-18). Relevant radiolucent lines and osteolysis were not found. INTERPRETATION The uncemented modular neck, dual-stem system used in this series allows accurate reconstruction of the joint by adapting the implant to the needs of the patient. This may improve the outcome of primary THA, which is supported by the results of this medium-term follow-up evaluation.
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Affiliation(s)
- Georg W Omlor
- Department of Orthopaedic Surgery, University of Heidelberg
| | - Hannah Ullrich
- Department of Orthopaedic Surgery Paulinenhilfe, Diakonie-Klinikum, StuttgartGermany
| | - Knut Krahmer
- Department of Orthopaedic Surgery Paulinenhilfe, Diakonie-Klinikum, StuttgartGermany
| | - Alexander Jung
- Department of Orthopaedic Surgery, University of Heidelberg
| | - Günther Aldinger
- Department of Orthopaedic Surgery Paulinenhilfe, Diakonie-Klinikum, StuttgartGermany
| | - Peter Aldinger
- Department of Orthopaedic Surgery, University of Heidelberg
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467
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Arai N, Nakamura S, Matsushita T, Suzuki S. Minimal radiation dose computed tomography for measurement of cup orientation in total hip arthroplasty. J Arthroplasty 2010; 25:263-7. [PMID: 19442484 DOI: 10.1016/j.arth.2009.01.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Accepted: 01/30/2009] [Indexed: 02/01/2023] Open
Abstract
We studied a computed tomography (CT) protocol with minimal radiation dose for measurements of cup orientation after total hip arthroplasty. Inclination and version angles were measured directly on cadaver pelvis fixed with an acetabular component. We performed the CT scanning on the phantom made of this model in 6 protocols as follows: tube current of 300, 100, 50, 30, 20, and 10 mA. The 30 mA protocol maintained good image quality for measurements with the smallest dose (1.1 millisievert), which corresponds to less than 2 times that of an anteroposterior radiograph of the pelvis. The differences of measured angles between direct and CT measurements on the phantom were less than 1 degrees. Measurements of cup orientation were possible by this protocol in 26 hips in 22 patients after total hip arthroplasty.
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Affiliation(s)
- Noriyuki Arai
- Department of Orthopedic Surgery, Teikyo University School of Medicine, Tokyo, Japan
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468
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Stiehl JB, Heck DA, Lazzeri M. Accuracy of acetabular component positioning with a fluoroscopically referenced CAOS system. ACTA ACUST UNITED AC 2010; 10:321-7. [PMID: 16410234 DOI: 10.3109/10929080500379499] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This study evaluated the accuracy, repeatability, and reproducibility of a fluoroscopic referenced system used for guiding acetabular component positioning. METHODS Calibration of the Medtronic StealthStation Treon Plus system was performed using a Weber gage block to assess linearity. Metrologic validation of repeatability and reproducibility was done using a cadaveric pelvis with an uncemented cup placed in the target position of 45 degrees inclination and 17.5 degrees anteversion. A baseline assessment was done with a National Institute of Standards and Technology (NIST) traceable coordinate measuring machine (CMM). RESULTS Weber gage block analysis revealed a mean bias of 0.69 mm. For the cadaveric pelvis, the anterior pelvic plane was determined using the bilateral anterior superior iliac spines with the symphysis pubis as the inferior landmark. The mean CMM measurement was inclination of 46.023 degrees (SD=1.075; range: 43.318-46.844 degrees) and anteversion of 15.787 degrees (SD=0.411; range: 15.068-16.384 degrees). One surgeon performed a repeatability assessment (n=8), finding mean inclination of 42.8 degrees (SD=1.5; range: 39.5-44.5 degrees) and anteversion of 17.5 degrees (SD=3.0; range: 14.5-22.5 degrees). Three surgeons performed a reproducibility assessment (n=24), finding mean overall inclination of 48.5 degrees (SD=0.9; range: 46-50 degrees) and anteversion of 17.8 degrees (SD=2.5; range: 13.5-23.5 degrees). All measurements were within a predefined acceptability range of+/-5 degrees. DISCUSSION The accuracy and reproducibility of the fluoroscopic referencing method was found to be suitable for determination of cup position in the surgical setting. Anteversion measurements were more variable for the fluoroscopic method and this may be related to the difficulty for the surgeon in predictably picking the anatomical points from the fluoroscopic image.
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Affiliation(s)
- James B Stiehl
- Department of Orthopaedic Surgery, Medical College of Wisconsin, Columbia St Mary's Hospital, Milwaukee, Wisconsin, USA.
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469
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Maheshwari AV, Zlowodzki MP, Siram G, Jain AK. Femoral neck anteversion, acetabular anteversion and combined anteversion in the normal Indian adult population: A computed tomographic study. Indian J Orthop 2010; 44:277-82. [PMID: 20697480 PMCID: PMC2911927 DOI: 10.4103/0019-5413.65156] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Abnormal femoral neck anteversion (FNA) and/or acetabulum anteversion (AA) have long been implicated in the etiogenesis of hip osteoarthritis (OA), developmental dysplasia of the hip (DDH), and impingement, instability and wear in total hip arthroplasty (THA). Since studies on the Indian population are sparse on this topic, the purpose of this study was to report the normal values of FNA, AA and the combined anteversion (CA= FNA+ AA) in Indian adults. MATERIALS AND METHODS FNA, AA and CA were prospectively measured in 172 normal hips in 86 Indian adults using standardized computed tomographic (CT) methods and this data was compared with the established Western values. RESULTS The median values and interquartile ranges were 8 degrees (6.5-10.0 degrees ) for FNA, 19 degrees (16.0-22.0 degrees ) for AA and 27 degrees (23.5-30.0 degrees ) for CA. AA and CA values were significantly (P<0.05) lower in males, and there was also a trend towards lower FNA in males. Although a negative correlation was observed between the FNA and AA, this was not strong and may not be clinically relevant. CONCLUSION When compared with the Western data, the FNA values were 3-12 degrees lower and the CA values were 3-5 degrees lower in Indian adults. The AA values were comparable, but were skewed towards the higher side. Further studies are needed to assess the clinical relevance of our basic science data in pathogenesis of OA, and to validate it in relation to hip surgeries like corrective osteotomies and THA.
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Affiliation(s)
- Aditya V Maheshwari
- Department of Orthopedics, University College of Medical Sciences, University of Delhi – 110 095, India,Department of Orthopedics, Washington Hospital Center, 110 Irving ST NW, Washington DC, USA - 200 10,Address for correspondence: Dr. Aditya V Maheshwari, Department of Orthopedics, Washington Hospital Center, 110 Irving ST NW, Washington DC, USA, 20010. E-mail:
| | - Michael P Zlowodzki
- Department of Orthopedics, University of Minnesota, R200, 2450 Riverside Ave S, Minneapolis, MN – 554 54
| | - Gautam Siram
- Department of Orthopedics, Washington Hospital Center, 110 Irving ST NW, Washington DC, USA - 200 10,Department of Orthopedics, Howard University Hospital, 2041 Georgia Avenue, Washington, DC –20060
| | - Anil K Jain
- Department of Orthopedics, University College of Medical Sciences, University of Delhi – 110 095, India
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470
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Ryan JA, Jamali AA, Bargar WL. Accuracy of computer navigation for acetabular component placement in THA. Clin Orthop Relat Res 2010; 468:169-77. [PMID: 19629609 PMCID: PMC2795805 DOI: 10.1007/s11999-009-1003-7] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Accepted: 07/10/2009] [Indexed: 01/31/2023]
Abstract
The accuracy and precision of any computer-aided surgical device is critical to its utility. We asked the following question: how accurate and precise are the values measured by an imageless computer navigation system as compared with those measured using postoperative CT scans? Twenty-five patients (26 hips) underwent primary THA using an imageless computer navigation system for placement of the acetabular component. Inclination and anteversion were measured in the operative coordinate system as defined by Murray. Accuracy, precision, and bias were computed, and Bland-Altman analysis was used to assess levels of agreement. The accuracy (mean +/- standard deviation of the absolute difference between computer-assisted navigation and CT) was 1.8 degrees +/- 1.2 degrees for inclination and 2.0 degrees +/- 2.0 degrees for anteversion. Precision was 3.4 degrees for inclination and 5.5 degrees for anteversion. Bias was 0.52 degrees for inclination and 0.35 degrees for anteversion. Limits of agreement were 4.26 degrees for inclination and 5.58 degrees for anteversion. An imageless computer navigation system can precisely determine acetabular cup position.
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Affiliation(s)
- James A. Ryan
- Department of Orthopaedics, Hospital for Special Surgery, New York, NY USA
| | - Amir A. Jamali
- Department of Orthopaedic Surgery, UC Davis Medical Center, Sacramento, CA USA
| | - William L. Bargar
- Joint Surgeons of Sacramento, Sutter General Hospital, 1020 29th Street, Suite 450, Sacramento, CA 95816 USA
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471
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Renkawitz T, Tingart M, Grifka J, Sendtner E, Kalteis T. Computer-assisted total hip arthroplasty: coding the next generation of navigation systems for orthopedic surgery. Expert Rev Med Devices 2009; 6:507-14. [PMID: 19751123 DOI: 10.1586/erd.09.34] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This article outlines the scientific basis and a state-of-the-art application of computer-assisted orthopedic surgery in total hip arthroplasty (THA) and provides a future perspective on this technology. Computer-assisted orthopedic surgery in primary THA has the potential to couple 3D simulations with real-time evaluations of surgical performance, which has brought these developments from the research laboratory all the way to clinical use. Nonimage- or imageless-based navigation systems without the need for additional pre- or intra-operative image acquisition have stood the test to significantly reduce the variability in positioning the acetabular component and have shown precise measurement of leg length and offset changes during THA. More recently, computer-assisted orthopedic surgery systems have opened a new frontier for accurate surgical practice in minimally invasive, tissue-preserving THA. The future generation of imageless navigation systems will switch from simple measurement tasks to real navigation tools. These software algorithms will consider the cup and stem as components of a coupled biomechanical system, navigating the orthopedic surgeon to find an optimized complementary component orientation rather than target values intraoperatively, and are expected to have a high impact on clinical practice and postoperative functionality in modern THA.
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Affiliation(s)
- Tobias Renkawitz
- Department of Orthopedic Surgery, Regensburg University Medical Center, Asklepios Klinikum Bad Abbach, Kaiser-Karl V-Allee 3, 93077 Bad Abbach, Germany.
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472
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Steppacher SD, Tannast M, Zheng G, Zhang X, Kowal J, Anderson SE, Siebenrock KA, Murphy SB. Validation of a new method for determination of cup orientation in THA. J Orthop Res 2009; 27:1583-8. [PMID: 19544389 DOI: 10.1002/jor.20929] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Our goal was to validate accuracy, consistency, and reproducibility/reliability of a new method for determining cup orientation in total hip arthroplasty (THA). This method allows matching the 3D-model from CT images or slices with the projected pelvis on an anteroposterior pelvic radiograph using a fully automated registration procedure. Cup orientation (inclination and anteversion) is calculated relative to the anterior pelvic plane, corrected for individual malposition of the pelvis during radiograph acquisition. Measurements on blinded and randomized radiographs of 80 cadaver and 327 patient hips were investigated. The method showed a mean accuracy of 0.7 +/- 1.7 degrees (-3.7 degrees to 4.0 degrees) for inclination and 1.2 +/- 2.4 degrees (-5.3 degrees to 5.6 degrees) for anteversion in the cadaver trials and 1.7 +/- 1.7 degrees (-4.6 degrees to 5.5 degrees) for inclination and 0.9 +/- 2.8 degrees (-5.2 degrees to 5.7 degrees) for anteversion in the clinical data when compared to CT-based measurements. No systematic errors in accuracy were detected with the Bland-Altman analysis. The software consistency and the reproducibility/reliability were very good. This software is an accurate, consistent, reliable, and reproducible method to measure cup orientation in THA using a sophisticated 2D/3D-matching technique. Its robust and accurate matching algorithm can be expanded to statistical models.
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Affiliation(s)
- Simon D Steppacher
- Center for Computer Assisted and Reconstructive Surgery, New England Baptist Hospital, Tufts University School of Medicine, Boston, Massachusetts, USA
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473
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Activities of daily living after total hip arthroplasty. Is a 32-mm femoral head superior to a 26-mm head for improving daily activities? INTERNATIONAL ORTHOPAEDICS 2009; 35:25-9. [PMID: 20091032 DOI: 10.1007/s00264-009-0909-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 10/27/2009] [Accepted: 10/31/2009] [Indexed: 10/20/2022]
Abstract
Range of motion (ROM) of the hip joint after total hip arthroplasty (THA) could be increased by using a larger prosthetic femoral head, but it is not known whether the activities of daily living (ADL) are influenced by THA with different head sizes. Our objective was to compare postoperative ADL in patients who underwent THA using a head diameter of 26 mm or 32 mm. We assessed the range of motion and the mode of ADL after cementless primary THA. Comparison was performed between 25 joints of 24 patients who underwent THA with a 26-mm femoral head (26-mm group) and 24 joints of 20 patients with a 32-mm head (32-mm group). The postoperative range of flexion and abduction was significantly larger in the 32-mm group than in the 26-mm group. With respect to the mode of performing selected ADL such as putting on and removing pants, socks, and cutting toenails, many patients adopted the compensatory position of lumbar flexion with hip flexion plus knee extension in the 26-mm group, while a majority of the patients from the 32-mm group employed the mode of hip flexion with knee flexion. Patients with the 32-mm head showed better postoperative ADL of the ipsilateral side compared with the 26-mm head.
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474
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Dorr LD, Wan Z, Malik A, Zhu J, Dastane M, Deshmane P. A comparison of surgeon estimation and computed tomographic measurement of femoral component anteversion in cementless total hip arthroplasty. J Bone Joint Surg Am 2009; 91:2598-604. [PMID: 19884433 DOI: 10.2106/jbjs.h.01225] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The intraoperative estimation of the anteversion of the femoral component of a total hip arthroplasty is generally made by the surgeon's visual assessment of the stem position relative to the condylar plane of the femur. Although the generally accepted range of intended anteversion is between 10 degrees and 20 degrees, we suspected that achieving this range of anteversion consistently during cementless implantation of the femoral component was more difficult than previously thought. METHODS We prospectively evaluated the accuracy of femoral component anteversion in 109 consecutive total hip arthroplasties (ninety-nine patients), in which we implanted the femoral component without cement. In all hips, we measured femoral stem anteversion postoperatively with three-dimensional computed tomography reconstruction of the femur, using both the distal femoral epicondyles and the posterior femoral condyles to determine the femoral diaphyseal plane. The bias and precision of the measurements were calculated. RESULTS The surgeon's estimate of femoral stem anteversion was a mean (and standard deviation) of 9.6 degrees +/- 7.2 degrees (range, -8 degrees to 28 degrees). The anteversion of the stem measured by computed tomography was a mean of 10.2 degrees +/- 7.5 degrees (range, -8.6 degrees to 27.1 degrees) (p = 0.324). The correlation coefficient between the surgeon's estimate and the computed tomographic measurement was 0.688; the intraclass coefficient was 0.801. Anteversion measured by computed tomography found that forty-nine stems (45%) were between 10 degrees and 20 degrees of anteversion; forty-three stems (39%) were between 0 degree and 9 degrees of femoral anteversion; eight stems (7%) were in anteversion of >20 degrees; and nine stems (8%) were in retroversion. CONCLUSIONS The surgeon's estimation of the anteversion of the cementless femoral stem has poor precision and is often not within the intended range of 10 degrees to 20 degrees of anteversion. The implications of this finding increase the importance of achieving a safe range of motion by evaluating the combined anteversion of the stem and the cup.
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Affiliation(s)
- Lawrence D Dorr
- The Arthritis Institute at Good Samaritan Hospital, 637 South Lucas Avenue, 5th Floor, Los Angeles, CA 90017, USA.
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475
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Dick C, Georgii J, Burgkart R, Westermann R. Stress tensor field visualization for implant planning in orthopedics. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 2009; 15:1399-1406. [PMID: 19834214 DOI: 10.1109/tvcg.2009.184] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate the application of advanced 3D visualization techniques to determine the optimal implant design and position in hip joint replacement planning. Our methods take as input the physiological stress distribution inside a patient's bone under load and the stress distribution inside this bone under the same load after a simulated replacement surgery. The visualization aims at showing principal stress directions and magnitudes, as well as differences in both distributions. By visualizing changes of normal and shear stresses with respect to the principal stress directions of the physiological state, a comparative analysis of the physiological stress distribution and the stress distribution with implant is provided, and the implant parameters that most closely replicate the physiological stress state in order to avoid stress shielding can be determined. Our method combines volume rendering for the visualization of stress magnitudes with the tracing of short line segments for the visualization of stress directions. To improve depth perception, transparent, shaded, and antialiased lines are rendered in correct visibility order, and they are attenuated by the volume rendering. We use a focus+context approach to visually guide the user to relevant regions in the data, and to support a detailed stress analysis in these regions while preserving spatial context information. Since all of our techniques have been realized on the GPU, they can immediately react to changes in the simulated stress tensor field and thus provide an effective means for optimal implant selection and positioning in a computational steering environment.
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Affiliation(s)
- Christian Dick
- Computer Graphics and Visualization Group, Technische Universität München, Germany.
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476
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Abstract
BACKGROUND AND PURPOSE Many studies have suggested that navigation-based implantation can improve cup positioning in total hip arthroplasty (THA). We conducted a systematic review and meta-analysis to compile the best available evidence, and to overcome potential shortcomings because of small sample sizes in individual studies. METHODS The search strategy covered the major medical databases from January 1976 through August 2007, as well as various publishers' databases. The internal validity of individual studies was evaluated independently by 3 reviewers. We used random-effects modeling to obtain mean differences in cup angulation and relative risk (RR) of cup positioning outside Lewinnek's safe zone. RESULTS Of 363 citations originally identified, 5 trials of moderate methodology enrolling a total of 400 patients were included in the analysis. Mean cup inclination and anteversion were not statistically significantly different between the conventional groups and the navigated groups. Navigation reduced the variability in cup positioning and the risk of placing the acetabular component beyond the safe zone (RR = 0.21, CI: 0.13-0.32). INTERPRETATION Based on the current literature, navigation is a reliable tool to optimize cup placement, and to minimize outliers. However, long-term outcomes and cost utility analyses are needed before conclusive statements can be drawn about the value of routine navigation in THA.
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Affiliation(s)
- Johannes Beckmann
- Department of Orthopedic Surgery, University of RegensburgBad AbbachGermany
| | - Dirk Stengel
- Depts f Trauma and Orthopaedic Surgery, Unfallkrankenhaus Berlin and University of GreifswaldGermany
| | - Markus Tingart
- Department of Orthopedic Surgery, University of RegensburgBad AbbachGermany
| | - Jürgen Götz
- Department of Orthopedic Surgery, University of RegensburgBad AbbachGermany
| | - Joachim Grifka
- Department of Orthopedic Surgery, University of RegensburgBad AbbachGermany
| | - Christian Lüring
- Department of Orthopedic Surgery, University of RegensburgBad AbbachGermany
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477
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Thorey F, Klages P, Lerch M, Floerkemeier T, Windhagen H, von Lewinski G. Cup positioning in primary total hip arthroplasty using an imageless navigation device: is there a learning curve? Orthopedics 2009; 32:14-7. [PMID: 19835301 DOI: 10.3928/01477447-20090915-52] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In this study, the success of cup positioning in total hip arthroplasty (THA) using an imageless navigation system was analyzed (1) during the learning period and (2) after the learning period for using the navigation system. Sixty THAs were performed in which threaded cups were placed with use of a computer-assisted navigation device (B. Braun Aesculap, Tuttlingen, Germany). Half of the procedures (30), group A, were done by the same surgeons under the learning curve for using the navigation system; the other half (30), group B, were done by surgeons who were no longer considered under the learning curve. Intraoperative acetabular component parameters (inclination, anteversion) for both groups were compared with postoperative radiographic alignment values. In group A, significant differences were seen between intraoperative and postoperative cup orientation. In group B, no significant differences were seen between intraoperative and postoperative cup orientation. Additionally, the percentage of outliers decreased in group B. Operating and anesthesia times significantly decreased with the surgeon's experience in imageless cup navigation. There was an individual increase of precision during the learning curve for all surgeons. Imageless navigation is a dependable and accurate method of cup positioning during THA. However, accuracy of cup placement and length of operating room time were affected by surgeons' experience using the system. Imageless navigation may lead to a reduction in the length of the learning curve for surgeons beginning to perform THAs, improvement in the surgeon's ability to perform this procedure safely, and minimization of outliers.
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Affiliation(s)
- Fritz Thorey
- Department of Orthopaedic Surgery, Hannover Medical School, 30625 Hannover, Germany
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478
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Hananouchi T, Saito M, Koyama T, Hagio K, Murase T, Sugano N, Yoshikawa H. Tailor-made surgical guide based on rapid prototyping technique for cup insertion in total hip arthroplasty. Int J Med Robot 2009; 5:164-9. [PMID: 19248055 DOI: 10.1002/rcs.243] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND A surgical guide made by the rapid prototyping (RP) technique for cup insertion in total hip arthroplasty might be useful to avoid malalignment of the cup, which indicates postoperative complications. METHODS To address this research question, we applied a RP-based guide to 24 patients with their CT images. We designed it to fit onto the acetabular edge and to insert a Kirschner wire (K-wire) which indicated a planned cup direction. We intraoperatively placed it on the acetabular edge, inserted the K-wire through the guide on the superior acetabulum and implanted the cup while observing the alignment of the K-wire. We also recorded the additional time needed to use the guide. RESULTS The mean cup accuracy between planned and postoperative alignments was 2.8 degrees (SD = 2.1 degrees ) for abduction and 3.7 degrees (SD = 2.7 degrees ) for anteversion. The mean additional time was 3.5 (range 2-6) min. CONCLUSION We can use this guide with acceptable accuracy and without consuming an excessive amount of time.
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Affiliation(s)
- Takehito Hananouchi
- Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
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479
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Heck DA, Stiehl JB. Six sigma analysis of minimally invasive acetabular arthroplasty: a preliminary investigation. Clin Orthop Relat Res 2009; 467:2025-31. [PMID: 19462215 PMCID: PMC2706362 DOI: 10.1007/s11999-009-0852-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Accepted: 04/08/2009] [Indexed: 01/31/2023]
Abstract
Minimally invasive techniques in THA may increase the difficulty of acetabular component insertion relative to the optimized position. We sought to determine the ability of eight surgeons to position an acetabular component placed using an anterior-lateral minimally invasive surgical (MIS) approach with conventional instruments or computer navigation using an optical imageless protocol compared with conventional true values determined by computed tomography (CT). We introduce a new approach, the Six Sigma process capability index, to assess outliers. Using the Six Sigma process capability index (Cp > 1.3) and the criteria of Lewinnek et al. of +/- 10 degrees for adequate precision, three-dimensional (3D) CT was capable for inclination and anteversion. Computer navigation and visual cues with conventional instrumentation were precise for anteversion but not for inclination. We conclude image-free computer navigation was not better than conventional instrumentation with the surgeons' visual cues for acetabular cup placement. Six Sigma analysis allows comparison of various methods of referencing with literature controls, and our data suggest CT referencing is the most precise method.
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Affiliation(s)
- David A. Heck
- Department of Surgery, Methodist Dallas Medical Center, Dallas, TX USA
| | - James B. Stiehl
- Department of Orthopaedic Surgery, Medical College of Wisconsin, Columbia St Mary’s Hospital, Milwaukee, WI USA ,575 W Riverwoods Parkway, #204, 53212 Milwaukee, WI USA
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480
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Abstract
The exact anatomical and biomechanical demands of correct positioning of prostheses can be critical for hip joint revision endoprosthetics. Preoperative planning cannot always be implemented due to the intraoperative situation. The reconstruction of the hip center, the correct alignment of the acetabulum and the shaft is difficult, especially in large defect situations. An exact positioning of the implant is possible for primary hip joint replacement by computer-assisted procedures. Although the potential benefits of revision endoprosthetics make sense, there are as yet only few publications which as a rule are limited to positioning of the acetabulum. It will be possible to further optimize revision endoprosthetics by analysis of the impingement, determination of alterations in leg length, measurement of shaft antetorsion and other parameters, by additionally incorporating shaft navigation and implant data. Navigation should, however, only be understood as an aid to orientation and does not supplant lack of knowledge and experience on the side of the operator. Information on positioning of the implant must therefore come from the operator.
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Affiliation(s)
- P A Grützner
- Klinik für Unfallchirurgie und Orthopädie, Klinikum Stuttgart-Katharinenhospital, Kriegsbergstrasse 60, 70174 Stuttgart, Deutschland.
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481
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Cup positioning in THA: current status and pitfalls. A systematic evaluation of the literature. Arch Orthop Trauma Surg 2009; 129:863-72. [PMID: 18600334 DOI: 10.1007/s00402-008-0686-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Indexed: 10/21/2022]
Abstract
The correct determination of cup orientation in THA regarding the intraoperative as well as the postoperative assessment due to the pelvic tilt and rotation with inexact incorporation of the pelvis is uncertain. The anterior pelvic plane (APP) seems to be the most reliable reference frame and computer-assisted navigation systems seem to provide the best tool for correct implantation to date. For the intraoperative assessment of the APP, the exact determination of the bony landmarks is mandatory. For the standard plain radiography, standardized positioning of the patient and approximation of pelvic tilt by a lateral view are mandatory. An additional CT must be carried out for certain indications. More emphasis has to be given to the individuality of pelvic tilt and range of motion.
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482
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Sugano N, Takao M, Sakai T, Nishii T, Miki H, Nakamura N. Comparison of mini-incision total hip arthroplasty through an anterior approach and a posterior approach using navigation. Orthop Clin North Am 2009; 40:365-70. [PMID: 19576404 DOI: 10.1016/j.ocl.2009.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This study reports on differences in the use of minimally invasive surgery for total hip arthroplasty related to the direction of cup insertion against the operating table, intraoperative hip range of motion, stability, and a choice of cup liners for both a mini-incision posterior approach (MPA) and a mini-incision anterior approach (MAA) using Stryker Navigation's CT-Hip system. The MPA group consisted of 39 consecutive patients and the MAA group consisted of 33 consecutive patients. Clinically, there was no significant difference in the average Japanese Orthopedic Association hip score or the Oxford hip score preoperatively and at 6 months and 2 years follow-up. The intraoperative joint stability measurements showed no large difference between the two groups when malpositioning of the cup was eliminated.
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Affiliation(s)
- Nobuhiko Sugano
- Department of Orthopedic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
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483
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Upward and inward displacements of the acetabular component increase stress on femoral head in single endoprothesis models. INTERNATIONAL ORTHOPAEDICS 2009; 34:479-83. [PMID: 19424694 DOI: 10.1007/s00264-009-0788-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 04/08/2009] [Accepted: 04/09/2009] [Indexed: 10/20/2022]
Abstract
The centre of rotation of the hip can be displaced in hip dysplasia and revision arthroplasty. This study examined the effect of artificial femoral head load after acetabular component displacement in total hip arthroplasty. Sixteen total hip arthroplasty models of human cadaver specimens were reconstructed, and under different acetabular component position, the load around the femoral head was evaluated by strain gages. The results showed that the load was higher in the same specimens when the cup was moved 2 mm inward or upward, especially after the cup was moved more than 6 mm, and the load had an increasing effect in the inward group. In the upward group, an increasing effect happened at 8 mm upward displacement, but the stress value decreased from 4 mm to 6 mm upward displacement. In the same moving distance, the stress of inward displacement is obviously higher than upward displacement. Altogether, the results suggested that for both inward displacement and upward displacement of the acetabular cup, the load around the femoral head increased gradually, while the distance of the inward displacement and the superior displacement was increased. The greater the displacement, the bigger the loading contact stress. The upward displacement caused less stress change on the femoral head. The stress of the 6 mm upward position was lower than nearby positions; perhaps this site represented a stress buffering zone.
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484
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Archbold HAP, Slomczykowski M, Crone M, Eckman K, Jaramaz B, Beverland DE. The relationship of the orientation of the transverse acetabular ligament and acetabular labrum to the suggested safe zones of cup positioning in total hip arthroplasty. Hip Int 2009; 18:1-6. [PMID: 18645966 DOI: 10.1177/112070000801800101] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND There is a need to develop and validate a method for establishing cup orientation that is patient specific and independent of the anterior pelvic plane. It is our hypothesis that the transverse acetabular ligament and acetabular labrum can be used to do this. The objective of this study is to define the orientation of the plane formed by the transverse acetabular ligament and acetabular labrum and to examine whether these local landmarks lie within the limits of acceptance for cup positioning. METHODS Twenty-five consecutive patients, who were being investigated for labral tears with a MRI arthrogram of the hip, were enrolled in this prospective study. The orientation of the transverse acetabular ligament-labrum plane was determined by manually selecting points on the transverse acetabular ligament and labrum. The best-fit plane through these points was determined and its operative orientation expressed with respect to a constructed pelvic coordinate system. RESULTS The operative anteversion of the transverse acetabular ligament-labrum plane ranged from 5.3-36.1 inverted exclamation mark (mean 23.0 inverted exclamation mark + or - 7.4 inverted exclamation mark standard deviation). The inclination ranged from 38.4-50.3 inverted exclamation mark (mean 45.6 inverted exclamation mark + or - 3.2 inverted exclamation mark standard deviation). CONCLUSIONS The transverse acetabular ligament and acetabular labrum offer a possible solution to the many difficulties involved in cup placement during total hip arthroplasty. This paper highlights the variation in the orientation of these local acetabular landmarks and questions the logic of a set target for cup positioning.
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Affiliation(s)
- H A P Archbold
- Outcomes Unit, Musgrave Park Hospital, Belfast, Northern Ireland, UK.
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485
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Malik A, Dorr LD, Long WT. Impingement as a mechanism of dissociation of a metasul metal-on-metal liner. J Arthroplasty 2009; 24:323.e13-6. [PMID: 18562156 DOI: 10.1016/j.arth.2008.05.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Accepted: 05/19/2008] [Indexed: 02/01/2023] Open
Abstract
This case report is of a patient with disassociation of the acetabular cup liner caused by impingement. The cup inclination (39 degrees) and anteversion (24 degrees) were good as measured by computer navigation. Impingement occurred because the head-neck ratio was 2.0, and the hip length and offset were short by one head length. Successful revision without intraoperative impingement was accomplished with one size head larger (32 mm; head-neck ratio, 2.3) and one size longer to correct hip length and offset.
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Affiliation(s)
- Aamer Malik
- The Arthritis Institute, Inglewood, California 90301, USA
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486
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Patient specific cup anteversion in total hip arthroplasty: a computed tomography study investigating the use of the transverse acetabular ligament to control cup placement. CURRENT ORTHOPAEDIC PRACTICE 2009. [DOI: 10.1097/bco.0b013e3181944dd2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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487
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Najarian BC, Kilgore JE, Markel DC. Evaluation of component positioning in primary total hip arthroplasty using an imageless navigation device compared with traditional methods. J Arthroplasty 2009; 24:15-21. [PMID: 18534411 DOI: 10.1016/j.arth.2008.01.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 01/01/2008] [Indexed: 02/01/2023] Open
Abstract
Acetabular orientation affects the success of total hip arthroplasty. Computer-assisted navigation systems may reduce positional errors. Total hip arthroplasty results were analyzed using an imageless navigation system. We hypothesized that reliability and accuracy would improve. One hundred forty-nine total hip arthroplasties were performed using minimally invasive surgical techniques in 3 cohorts: manual (n = 53), initial navigation cases (n = 49), navigation second series (n = 47). Manual patients' cup orientation variation from desired range was -19 degrees to +18 degrees anteversion (SD, 9.1 degrees ), -11 degrees to +25 degrees abduction (SD, 6.7 degrees ). Navigation variation from desired was -18 degrees to +15 degrees (SD, 7.3 degrees ) in group 1 and -15 degrees to +9 degrees (SD, 5.9 degrees ) in group 2 in anteversion and -15 degrees to +13 degrees (SD, 6.1 degrees ) in group 1 and -15 degrees to +11 degrees (SD, 4.7 degrees ) in group 2 in abduction. Results were statistically significant. There were significant differences for operating room time and estimated blood loss, but not incision size or body mass index. Navigation provided controlled, reproducible acetabular alignment; but a learning curve existed in terms of accuracy, estimated blood loss, and operating room time.
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Affiliation(s)
- Brian C Najarian
- Department of Orthopaedic Surgery Wayne State University School of Medicine, Detroit, Michigan, USA
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488
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Wan Z, Malik A, Jaramaz B, Chao L, Dorr LD. Imaging and navigation measurement of acetabular component position in THA. Clin Orthop Relat Res 2009; 467:32-42. [PMID: 18979147 PMCID: PMC2600979 DOI: 10.1007/s11999-008-0597-5] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Accepted: 10/14/2008] [Indexed: 01/31/2023]
Abstract
There are six different definitions of acetabular position based on observed inclination and anteversion made in either the (1) anterior pelvic plane or (2) coronal planes and based on whether each of the observations made in one of these two planes is (1) anatomic, (2) operative, or (3) radiographic. Anteroposterior pelvic tilt is the angle between the anterior pelvic plane and the coronal plane of the body. The coronal plane is a functional plane and the anterior pelvic plane is an anatomic pelvic plane. A cup may be in the "safe zone" by one definition but may be out of the "safe zone" by another definition. We reviewed published studies, analyzed the difference in varying definitions, evaluated the influence of the anterior pelvic tilt, and provided methods to convert from one definition to another. We recommend all inclination and anteversion measurements be converted to the radiographic inclination and anteversion based on the coronal plane, which is equivalent to the inclination and anteversion on the anteroposterior pelvic radiograph.
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Affiliation(s)
- Zhinian Wan
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Aamer Malik
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Branislav Jaramaz
- Simulation and Interactive Media, Innovation Center, Magee Womens Hospital of UPMC, 3380 Boulevard of the Allies, Suite 270, Pittsburgh, PA 15213 USA
| | - Lisa Chao
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Lawrence D. Dorr
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
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489
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Computer-assisted versus manual alignment in THA: a probabilistic approach to range of motion. Clin Orthop Relat Res 2009; 467:50-5. [PMID: 18941857 PMCID: PMC2600980 DOI: 10.1007/s11999-008-0561-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 09/23/2008] [Indexed: 01/31/2023]
Abstract
Dislocation remains a major complication after THA, and range of motion before impingement is important in joint stability. Variability in implant alignment affects resultant range of motion. We used a probabilistic modeling approach to assess the effects of implant alignment variability based on manual and computer-assisted surgical (CAS) techniques on resultant range of motion after THA. We implemented a contact detection algorithm within a probabilistic analysis framework. The normally distributed alignment variables (mean +/- 1 standard deviation) were cup abduction (manual = 45 degrees +/- 7.6 degrees , CAS = 45 degrees +/- 5.7 degrees ), cup anteversion (manual = 20 degrees +/- 9.6 degrees , CAS = 20 degrees +/- 4.5 degrees ), and stem anteversion (manual and CAS = 10 degrees +/- 1.5 degrees ). The outcomes of the probabilistic analysis were range of motion distributions with 1% and 99% bounds. The upper bounds of motion for manual and CAS alignment were similar because bony impingement was the limiting factor. The lower bounds of range of motion were substantially different depending on the type of surgical alignment; manual alignment produced a smaller range of motion in 3% to 5% of cases. CAS implant alignment produced range of motion values above minimum acceptable levels in all cases simulated.
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490
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Dorr LD, Malik A, Dastane M, Wan Z. Combined anteversion technique for total hip arthroplasty. Clin Orthop Relat Res 2009; 467:119-27. [PMID: 18979146 PMCID: PMC2600986 DOI: 10.1007/s11999-008-0598-4] [Citation(s) in RCA: 306] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 10/14/2008] [Indexed: 01/31/2023]
Abstract
UNLABELLED Combined cup and stem anteversion in THA based on femoral anteversion has been suggested as a method to compensate for abnormal femoral anteversion. We investigated the combined anteversion technique using computer navigation. In 47 THAs, the surgeon first estimated the femoral broach anteversion and validated the position by computer navigation. The broach was then measured with navigation. The navigation screen was blocked while the surgeon estimated the anteversion of the broach. This provided two estimates of stem anteversion. The navigated stem anteversion was validated by postoperative CT scans. All cups were implanted using navigation alone. We determined precision (the reproducibility) and bias (how close the average test number is to the true value) of the stem position. Comparing the surgeon estimate to navigation anteversion, the precision of the surgeon was 16.8 degrees and bias was 0.2 degrees ; comparing the navigation of the stem to postoperative CT anteversion, the precision was 4.8 degrees and bias was 0.2 degrees , meaning navigation is accurate. Combined anteversion by postoperative CT scan was 37.6 degrees +/- 7 degrees (standard deviation) (range, 19 degrees -50 degrees ). The combined anteversion with computer navigation was within the safe zone of 25 degrees to 50 degrees for 45 of 47 (96%) hips. Femoral stem anteversion had a wide variability. LEVEL OF EVIDENCE Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Lawrence D. Dorr
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Aamer Malik
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Manish Dastane
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
| | - Zhinian Wan
- The Arthritis Institute at Good Samaritan Hospital, 637 S. Lucas Avenue, 5th Floor, Los Angeles, CA 90017 USA
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491
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Optimal orientation of implanted components in total hip arthroplasty with polyethylene on metal articulation. Clin Biomech (Bristol, Avon) 2008; 23:996-1003. [PMID: 18550233 DOI: 10.1016/j.clinbiomech.2008.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 04/15/2008] [Accepted: 04/17/2008] [Indexed: 02/07/2023]
Abstract
BACKGROUND In many studies related to the total hip arthroplasty, it has been found that incorrect alignment of the total hip component is one of the major factors influencing mechanical failures. Although various recommendations for cup orientation have been presented, there were few studies that seek to determine a proper orientation of the implants based on the human motion data. The objective of this study is to determine an optimum orientation of the hip implant considering various daily activities. METHODS Firstly, the cup orientations free of impingement were calculated for a given set of implant geometric parameters and the required range of motion for daily activities measured in 10 subjects. Next, the optimum values for the cup orientation and stem anteversion avoiding impingement and minimizing cup wear were determined for the proposed motion criteria. FINDINGS Different cup orientation was obtained as optimum for each combination of the neck angles (40 degrees and 50 degrees) and oscillation angles (120 degrees and 135 degrees). The corresponding optimum stem anteversion was also different when different neck angle was used. INTERPRETATION As the margin for the impingement-free orientation of the cup was small, the optimum cup orientation and stem anteversion should be adopted specific for each combination of the neck angle and oscillation angle.
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492
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Amuwa C, Dorr LD. The combined anteversion technique for acetabular component anteversion. J Arthroplasty 2008; 23:1068-70. [PMID: 18534533 DOI: 10.1016/j.arth.2008.04.025] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Accepted: 04/13/2008] [Indexed: 02/01/2023] Open
Abstract
The combined anteversion technique for acetabular component placement of total hip arthroplasty is beneficial because of the surgeons' limited ability to control the anteversion of a cementless femoral stem. Our data show that the cementless stem anteversion can be 15 degrees different than anticipated. By determining femoral stem anteversion before positioning cup anteversion, the cup anteversion can be adjusted for the stem anteversion. The combined anteversion technique should provide a mean near 35 degrees with a safe zone of 25 degrees to 50 degrees.
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Affiliation(s)
- Christopher Amuwa
- The Arthritis Institute at Good Samaritan Hospital, Los Angeles, California 90017, USA
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493
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Affiliation(s)
- Lawrence D Dorr
- The Arthritis Institute at Good Samaritan Hospital, 637 S Lucas Ave, 5th Floor, Los Angeles, CA 90017, USA
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494
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An in vivo model for intraoperative assessment of impingement and dislocation in total hip arthroplasty. J Arthroplasty 2008; 23:714-20. [PMID: 18534546 DOI: 10.1016/j.arth.2007.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Accepted: 07/07/2007] [Indexed: 02/01/2023] Open
Abstract
We have developed an intraoperative model to quantify total hip arthroplasty impingement and dislocation mechanics using fluoroscopy and shape-matching techniques. Two patient groups were investigated: group 1 consisted of 12 hips using 28- or 32-mm femoral heads and an anterolateral surgical approach, and group 2 consisted of 17 hips using 22- or 26-mm femoral heads and a posterolateral surgical approach. During intraoperative hip stability testing consisting of extension and external rotation motions, group 1 was more unstable, and prosthetic impingement was the major reason for dislocation. With flexion and internal rotation motions, group 2 was more unstable, and superior-lateral impingement or soft tissue traction was the major reason for dislocation. Intraoperative quantitative assessment of hip mechanics provides a safe and clinically relevant method to characterize potential complications and evolve techniques to prevent them.
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495
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McMinn DJW, Daniel J, Ziaee H, Pradhan C. Results of the Birmingham Hip Resurfacing dysplasia component in severe acetabular insufficiency. ACTA ACUST UNITED AC 2008; 90:715-23. [DOI: 10.1302/0301-620x.90b6.19875] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The dysplasia cup, which was devised as an adjunct to the Birmingham Hip Resurfacing system, has a hydroxyapatite-coated porous surface and two supplementary neutralisation screws to provide stable primary fixation, permit early weight-bearing, and allow incorporation of morcellised autograft without the need for structural bone grafting. A total of 110 consecutive dysplasia resurfacing arthroplasties in 103 patients (55 men and 48 women) performed between 1997 and 2000 was reviewed with a minimum follow-up of six years. The mean age at operation was 47.2 years (21 to 62) and 104 hips (94%) were Crowe grade II or III. During the mean follow-up of 7.8 years (6 to 9.6), three hips (2.7%) were converted to a total hip replacement at a mean of 3.9 years (2 months to 8.1 years), giving a cumulative survival of 95.2% at nine years (95% confidence interval 89 to 100). The revisions were due to a fracture of the femoral neck, a collapse of the femoral head and a deep infection. There was no aseptic loosening or osteolysis of the acetabular component associated with either of the revisions performed for failure of the femoral component. No patient is awaiting a revision. The median Oxford hip score in 98 patients with surviving hips at the final review was 13 and the 10th and the 90th percentiles were 12 and 23, respectively.
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Affiliation(s)
- D. J. W. McMinn
- The McMinn Centre, 25 Highfield Road, Edgbaston, Birmingham B15 3DP, UK
| | - J. Daniel
- The McMinn Centre, 25 Highfield Road, Edgbaston, Birmingham B15 3DP, UK
| | - H. Ziaee
- The McMinn Centre, 25 Highfield Road, Edgbaston, Birmingham B15 3DP, UK
| | - C. Pradhan
- The McMinn Centre, 25 Highfield Road, Edgbaston, Birmingham B15 3DP, UK
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496
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THA using an anatomic stem in patients with femoral head osteonecrosis. Clin Orthop Relat Res 2008; 466:1141-7. [PMID: 18327627 PMCID: PMC2311464 DOI: 10.1007/s11999-008-0202-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Accepted: 02/19/2008] [Indexed: 01/31/2023]
Abstract
Treating young patients with femoral head osteonecrosis (ON) remains challenging. Anatomic stems were introduced in the 1980s and 1990s to improve the proximal canal fit in an attempt to enhance long-term implant survival, an important aspect of treating young patients. We began using one design in 1993 and asked three questions to confirm whether the design criteria improved outcomes in patients with ON: (1) What is the long term survivorship of these implants?; (2) What is the amount and rate of wear?; and (3) What is the incidence of osteolysis? We retrospectively reviewed 56 patients (69 hips) who underwent THA for femoral head ON with a cementless anatomic stem proximally coated with hydroxyapatite. Four patients (four hips) were lost to followup and 16 patients (19 hips) died. In the remaining 36 patients (46 hips) the minimum followup was 10 years (mean, 11.2 years; range, 10-13 years). The mean age at operation was 48.6 years. The average Harris hip score at last followup was 87 points. Worst-case survivorship was 58.1% at 13 years and best-case was 93.3%. The average linear wear of the polyethylene liner was 2.02 mm and the average annual wear was 0.18 mm per year. Thirty-seven hips (80%) had femoral osteolysis and 14 (30%) had acetabular osteolysis. One patient who had extensive femoral osteolysis and stem loosening was revised at 11.2 years postoperatively. The high rates of polyethylene wear and osteolysis are of concern.
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497
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Kessler O, Patil S, Wirth S, Mayr E, Colwell CW, D'Lima DD, D'Lima DD. Bony impingement affects range of motion after total hip arthroplasty: A subject-specific approach. J Orthop Res 2008; 26:443-52. [PMID: 18050356 DOI: 10.1002/jor.20541] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hip range of motion after total hip arthroplasty has been shown to be dependent on prosthetic design and component placement. We hypothesized that bony anatomy would significantly affect range of motion. Computer models of a current generation hip arthroplasty design were virtually implanted in a model of pelvis and femur in various orientations ranging from 35 degrees to 55 degrees cup abduction, 0 degrees to 30 degrees cup anteversion, and 0 degrees to 30 degrees femoral anteversion. Four head sizes ranging from 22.2 to 32 mm and two neck sizes ranging from 10-mm and 12-mm diameter were tested. Range of motion was recorded as maximum flexion-extension, abduction-adduction, and axial rotation of the femur before any contact between prosthetic components or bone was detected. Bony impingement preceded component impingement in about 44% of all conditions tested, ranging from 66% in adduction to 22% in extension. Range of motion increased as head size increased. However, increasing head size also increased the propensity for bony impingement, which tended to reduce the beneficial effect of increased head size on range of motion. Reducing neck diameter had a greater effect on prosthetic impingement (mean, 3.5 degrees increase in range of motion) compared to bone impingement (mean, 1.9 degrees ). This model allowed for a clinically relevant assessment of range of motion after total hip arthroplasty and may also be used with patient-specific geometry [such as that obtained from preoperative computed tomography (CT) scans] for more accurate preoperative planning.
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Affiliation(s)
- Oliver Kessler
- Scientific Affairs, Stryker Europe, Thalwil, Switzerland
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498
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Yoon YS, Hodgson AJ, Tonetti J, Masri BA, Duncan CP. Resolving inconsistencies in defining the target orientation for the acetabular cup angles in total hip arthroplasty. Clin Biomech (Bristol, Avon) 2008; 23:253-9. [PMID: 18069102 DOI: 10.1016/j.clinbiomech.2007.10.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 10/25/2007] [Accepted: 10/26/2007] [Indexed: 02/07/2023]
Abstract
BACKGROUND Dislocation following total hip arthroplasty is a major complication and malorientation of the acetabular cup is one of the primary factors affecting dislocation. Different conventions used to describe the cup orientation produce significant variations in the recommendations for correct positioning, which in turn make it difficult for clinicians to properly interpret and apply previously reported studies. METHODS We examined nine articles presenting recommendations for the range of target orientations of the acetabular cup to minimize the risk of dislocation (referred to as the 'safe zone'). Those studies included five ways to define the cup orientation and two methods to define the reference frame. We converted those recommendations to a single representation based on the radiographic angles expressed in the pelvic frame reference. FINDINGS After conversion, the mean recommended anteversion angle was shifted downward by 5 degrees (P<0.01). Also, the target orientation recommendations became more consistent, especially for the anteversion angles where the standard errors of the upper and lower limits were reduced by 61% (P=0.02) and 23% (P=0.04), respectively. INTERPRETATION The choice of reference frame and the definition for acetabular cup orientation angles can have a significant effect on the target orientation for the acetabular cup. Recommendations for the target orientation should always explicitly state which reference frame and angle definition is being used. The averaged recommendation of the studies assessed here is 41 degrees inclination and 16 degrees anteversion in radiographic angles or 39 degrees inclination and 21 degrees anteversion in operative angles, both expressed in the pelvic reference frame.
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Affiliation(s)
- Yong-San Yoon
- Department of Mechanical Engineering, KAIST, Daejeon, Republic of Korea.
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499
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Koo KH, Ha YC, Jung WH, Kim SR, Yoo JJ, Kim HJ. Isolated fracture of the ceramic head after third-generation alumina-on-alumina total hip arthroplasty. J Bone Joint Surg Am 2008; 90:329-36. [PMID: 18245593 DOI: 10.2106/jbjs.f.01489] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND While most reports of component fracture following alumina-on-alumina total hip arthroplasty have involved the acetabular liner, few have involved fracture of the alumina femoral head. In the present multicenter study, we investigated ceramic head fractures in a cohort of patients who underwent third-generation alumina-on-alumina total hip arthroplasty. METHODS We performed a retrospective study of 312 patients (367 hips) who underwent alumina-on-alumina total hip arthroplasty without cement at four participating centers with the use of a 28-mm BIOLOX forte femoral head and a BIOLOX forte liner from July 2001 to October 2003. Three hundred and five patients (359 hips) were evaluated at a mean of forty-five months postoperatively. Clinical follow-up with use of the Harris hip score and radiographic evaluation were performed at six weeks; at three, six, and twelve months; and every six months thereafter. Retrieved ceramic implants were examined by means of visual inspection. RESULTS Five hips (1.4%) in five patients were revised because of a ceramic head fracture during the follow-up period. The ceramic head fractures occurred during normal daily activities at a mean of 22.6 months postoperatively. A short neck had been used in all five hips in which a fracture occurred, compared with 121 (34.2%) of the 354 hips in which a fracture did not occur (p = 0.009). The fracture involved a circular crack along the circumference of the thinnest portion of the head component at the proximal edge of the bore. The fracture also involved multiple vertical cracks extending radially along the longitudinal axis from the circumference of the circular crack line to the lower edge of the head component. CONCLUSIONS In the present study, the rate of ceramic head fracture associated with one design of a short-neck modular alumina femoral head was 1.4% (five of 359). The extent to which these findings are generalizable to other designs that utilize this type of femoral head is unknown.
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Affiliation(s)
- Kyung-Hoi Koo
- Department of Orthopaedic Surgery, Seoul National University College of Medicine, 28 Yeongeon-dong, Jongno-gu, Seoul 110-744, South Korea
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500
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Wan Z, Boutary M, Dorr LD. The influence of acetabular component position on wear in total hip arthroplasty. J Arthroplasty 2008; 23:51-6. [PMID: 18165028 DOI: 10.1016/j.arth.2007.06.008] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 06/18/2007] [Indexed: 02/01/2023] Open
Abstract
Our experience has implicated cup inclination as an important factor in wear, whereas others have suggested that the hip center of rotation (COR) must be closely reestablished to reduce wear. We conducted a retrospective study to determine the relative importance of these 2 factors. One hundred thirty-nine total hip arthroplasties were studied after a mean follow-up of 9.2 years (range, 6-3 years). Forty-nine of 139 operated hips had a contralateral normal hip, which allowed the most accurate measurement of the influence of change in the COR. Wear was related to the inclination of the cup but not to a change in the COR. Secondarily, wear was less with a ceramic-polyethylene polyarticular surface than with metal-polyethylene. The importance of this data is related to cup implantation techniques. The hip COR can be moved superiorly and/or medially to permit cup inclination below 45 degrees with correct cup coverage.
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Affiliation(s)
- Zhinian Wan
- Arthritis Institute, Inglewood, CA 90301, USA
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