How Superior Placement of the Joint Center in Hip Arthroplasty Affects the Abductor Muscles

Delp, Scott L.; Wixson, Richard L.; Komattu, Abraham V.; Kocmond, Jonathan H.

doi:10.1097/00003086-199607000-00022

Cited by 151 publications

(102 citation statements)

References 24 publications

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“…None of the patients with a hip center above 35 mm failed, the grade of osseointegration was 5 in one patient, 4 in two patients, and 3 in two patients. Although a purely elevated hip center of rotation may not necessarily lead to poor hip abductor function if an increased neck length is used [12], the increased lever arm acting on the head/neck taper in this situation is a potential cause for concern. Elevation of the hip center may also require trochanteric advancement and pelvic osteoplasty to restore the abductor function and prevent impingement and instability [11].…”

Section: Discussionmentioning

confidence: 99%

Continued Good Results With Modular Trabecular Metal Augments for Acetabular Defects in Hip Arthroplasty at 7 to 11 Years

Whitehouse

Masri

Duncan

et al. 2015

Clinical Orthopaedics &Amp; Related Research

103

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Background Reconstruction of large acetabular defects remains a substantial challenge in hip arthroplasty. There remains a paucity of data on the long-term results of acetabular trabecular metal augments. Questions/purposes The purpose of this study was to assess the survivorship, clinical outcomes, restoration of center of rotation of the hip, and radiological signs of component fixation of trabecular metal augments in the context of reconstruction of acetabular defects. Methods Between 2002 and 2005, we performed 56 revision (n = 53) and primary (n = 3) THAs using trabecular metal augments in combination with a trabecular metal acetabular component. Of the 56 patients, 16 (29%) died during followup. Of the 40 surviving patients, 37 (93%) had complete radiological followup, 23 (58%) had complete outcome questionnaire followup, and 17 (42%) provided partial questionnaire responses in the clinic or over the telephone. Median followup was 110 months (range, 88-128 months). During that period, we used these implants when preoperative templating indicated that an augment would be required to achieve acetabular implant stability with restoration of the hip center of rotation. We also chose during surgery to use an augment when we could not achieve a stable acetabular trial component without one. The combination of trabecular metal augments and trabecular metal shells was used in 18% (53 of 292) of our acetabular revisions during that time. Survivorship, functional outcome (WOMAC and Oxford hip score), health status (SF-12), and osseointegration according to the criteria of Moore and presence of radiolucencies were determined.

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Section: Discussionmentioning

confidence: 99%

Continued Good Results With Modular Trabecular Metal Augments for Acetabular Defects in Hip Arthroplasty at 7 to 11 Years

Whitehouse

Masri

Duncan

et al. 2015

Clinical Orthopaedics &Amp; Related Research

103

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“…The effects of gait on hip loading are not as well understood as the effects of joint positioning, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] even though gait deficits after THR have been repeatedly observed. [20][21][22][23] Joint positions linked to high forces or adverse THR outcome include superior or lateral hip joint center, a small abductor moment arm, and a small offset.…”

mentioning

confidence: 99%

“…The hypothesis was that gait parameters would be better predictors of implant force (peak contact forces and peak twisting moment during walking) than joint positioning parameters. The joint positioning parameters, selected based on the literature, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] were the horizontal and vertical position of the hip center, the length of the abductor moment arm, and the offset. The hypothesis was tested using standard gait analysis techniques, clinical radiographs, and a parametric hip force model.…”

mentioning

confidence: 99%

Relative importance of gait vs. joint positioning on hip contact forces after total hip replacement

Foucher

Hurwitz

Wimmer

2009

Journal Orthopaedic Research

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Implant loosening is a common indication for total hip replacement (THR) revision. High contact forces and implant twisting moments are thought to be associated with implant loosening. Relationships between joint positioning and hip forces, or outcomes, have been investigated through in vivo and in vitro modalities. Relationships between hip forces and gait are less understood, despite repeated findings that gait following a THR does not fully return to normal. We tested the hypothesis that gait parameters would be better predictors of implant force (peak contact forces and peak twisting moment during walking) than joint positioning parameters. Subjects underwent gait analysis, hip force modeling, and measurement of clinical radiographs 1 year after successful THR surgery. Gait parameters were consistently more influential in determining hip forces. Alone, gait explained as much as 67% of the variation in force, compared to a maximum of 33% by joint geometry. Combinations of gait and joint positioning parameters together explained up to 86% of the variation in hip force parameters. Results suggest that gait may provide a valuable postoperatively modifiable target to improve hip loads and potentially reduce the risk for implant loosening. ß

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“…The position of the hip center is crucial for optimal functioning of the hip musculature [2,[10][11][12], for reducing joint contact forces [18], and for avoiding accelerated wear, impingement, and loosening [9,22,28]. Its accurate determination is a major variable over which the surgeon has some control in reconstructive surgery around the hip.…”

Section: Discussionmentioning

confidence: 99%

“…The joint contact forces about a reconstructed hip are greater when the hip center is located superiorly, laterally, and posteriorly compared with the original location [18]. Moreover, the force-and momentgenerating capacities of the hip muscles are sensitive to the location of the hip center [2,[10][11][12]. A 2-cm superior displacement, for instance, decreases abduction force by 44% and moment by 49%, whereas a 2-cm medial displacement decreases adduction force by 26% and moment by 40% [10].…”

Section: Introductionmentioning

confidence: 99%

Can the Acetabular Position be Derived from a Pelvic Frame of Reference?

Dandachli

Nakhla

Iranpour

et al. 2008

Clin Orthop Relat Res

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Acetabular center positioning has an effect on hip function. However, reported clinical and plain radiographic methods are inaccurate and unreliable for ascertaining acetabular implant location. In an exploratory study we asked whether the normal acetabular position can be derived from simple radiographically measurable pelvic dimensions. We analyzed computed tomographic scans of 37 normal hips using a pelvic frame of reference centered on the ipsilateral anterior-superior iliac spine. We defined the x-, y-, and z-coordinates of the hip center (C x ,C y ,C z ) as a percentage of the corresponding pelvic dimensions (D x ,D y ,D z ). C x /D x averaged 9%, C y /D y 34%, and C z /D z 37%. These ratios had narrow distributions with small confidence intervals. Interobserver agreement tests showed a mean intraclass correlation coefficient of 0.95. We observed gender differences in the ratios of as much as 4%, which correspond to differences of as much as 9 mm in the hip center position. The ratios provide a simple and reliable way of deriving the normal position of the hip center from the pelvic dimensions alone. This gives the surgeon a simple way of planning where the hip center should be and may be particularly helpful in revision hip arthroplasty or in cases involving extensive osteophytes, dysplasia, or protrusio.

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How Superior Placement of the Joint Center in Hip Arthroplasty Affects the Abductor Muscles

Cited by 151 publications

References 24 publications

Continued Good Results With Modular Trabecular Metal Augments for Acetabular Defects in Hip Arthroplasty at 7 to 11 Years

Continued Good Results With Modular Trabecular Metal Augments for Acetabular Defects in Hip Arthroplasty at 7 to 11 Years

Relative importance of gait vs. joint positioning on hip contact forces after total hip replacement

Can the Acetabular Position be Derived from a Pelvic Frame of Reference?

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