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David J. Mayman - One of the best experts on this subject based on the ideXlab platform.

  • SAGITTAL Pelvic Tilt DOES NOT CHANGE AFTER UNILATERAL TOTAL HIP REPLACEMENT
    Journal of Bone and Joint Surgery-british Volume, 2014
    Co-Authors: Joseph D. Maratt, Christina Esposito, Alexander S. Mclawhorn, Kaitlin M. Carroll, Seth A. Jerabek, David J. Mayman
    Abstract:

    Sagittal Pelvic Tilt (PT) has been shown to effect the functional position of acetabular components in patients with total hip replacements (THR). This change in functional component position may have clinical implications including increased likelihood of wear or dislocation. Surgeons can use computer-assisted navigation intraoperatively to account for a patient9s Pelvic Tilt and to adjust the position of the acetabular component. However, the accuracy of this technique has been questioned due to the concern that PT may change after THR. The purpose of this study was to measure the change in PT after THR, and to determine if preoperative clinical and radiographic parameters can predict PT changes after THR. 138 consecutive patients who underwent unilateral THR by one surgeon received standing bi-planar lumbar spine and lower extremity radiographs preoperatively and six weeks postoperatively. Patients with prior contralateral THR, conversion THR and instrumented lumbosacral fusions were excluded. PT and Pelvic incidence (PI) were measured preoperatively for each patient, and PT was measured on the postoperative imaging. A negative value for PT indicated posterior Pelvic Tilt. Patient demographics were collected from the chart. Average age was 56.8±10.9 years, average BMI was 28.3±6.0 kg/m2, and 67 patients (48.6%) were female. Mean preoperative Pelvic Tilt was 0.6°±7.3° (range: −19.0° to 17.9°). We found greater than 10° of sagittal PT in 23 out of 138 (16.6%) patients in this sample. Mean post-operative Pelvic Tilt was 0.3°±7.4° (range: −18.4° to 15.0°). Mean change in Pelvic Tilt was −0.3°±3.6° (range: −9.6° to 13.5°). PT changed by less than 5° in 119 of 138 patients (86.2%). The mean difference in pre-operative and post-operative PT is not statistically significant (p = 0.395). Pre-operative PT was strongly correlated with post-operative PT (r2 = 0.88, p = 0.0001) (Figure 1). There was not a statistically significant relationship between PI and change in PT (r2 = −0.16, p = 0.06). In conclusion, based on the variability in Pelvic Tilt in this study population and the relatively small change in Pelvic Tilt following THA Tilt-adjustment of the acetabular component position based on standing pre-operative imaging is likely to be of benefit in the majority of patients undergoing navigated THA. However, we have been unable to predict the relatively rare occurrence of a large change in Pelvic Tilt, which would confound Tilt-adjusted component position.

  • Accuracy of Pelvic Tilt Adjusted Anteversion Measurements in Imageless Navigation
    Journal of Bone and Joint Surgery-british Volume, 2013
    Co-Authors: Benjamin A. Mcarthur, Matthew J. Grosso, Brian Michaels, David J. Mayman
    Abstract:

    Introduction Traditional methods of component positioning in total hip replacement (THR) utilize mechanical alignment guides which estimate position relative to the plane of the operating room table. However, variations in Pelvic Tilt alter the relationship between the anatomic plane of the pelvis and that of the table such that components placed in optimal position relative the table may not land within the classic anatomic “safe zone” described by Lewinnek. It has been suggested that navigation software should incorporate adjustments for the degree of Pelvic Tilt. Current imageless navigation software has this capability, however there is a paucity of data regarding the accuracy of this technology. Purpose We aimed to assess the accuracy of intra-operative Pelvic Tilt adjusted anteversion measurements as compared to unadjusted measurements. Methods 6-week post-operative Anteroposterior Pelvis radiographs from 27 consecutive primary THR were measured utilizing Ein-Bild-Roentgen-Analyse (EBRA-Cup®) hip analysis software (Figure 1) and a cross-table lateral radiograph (Figure 2). Inclination and anteversion values were recorded and direction of version was confirmed by assessment of cross-table lateral images. Values were compared with intra-operative measurements obtained via BrainLab® imageless navigation. Pelvic Tilt adjusted and unadjusted anteversion measurements were recorded. Mean measurement error and standard error of the mean were determined and Pearson correlation coefficients were calculated. Results Navigated component inclination correlated with EBRA-Cup® derived inclination measurements (r = 0.4308, p = 0.02) with a mean error of 3.8°. Similarly, Pelvic Tilt adjusted anteversion correlated with EBRA-Cup® derived measurements (r = 0.65, p Conclusions Imageless navigation based anteversion measurements are more accurate when adjusted for Pelvic Tilt.

J Pierrepont - One of the best experts on this subject based on the ideXlab platform.

  • THE CLINICAL RELEVANCE OF FUNCTIONAL Pelvic Tilt: A PRE-OPERATIVE ANALYSIS OF 1517 PATIENTS
    2018
    Co-Authors: R. Reitman, J Pierrepont, S Mcmahon, Len Walter, Andrew Shimmin, E. Kerzhner
    Abstract:

    IntroductionThe pelvis is not a static structure. It rotates in the sagittal plane depending upon the activity being performed. These dynamic changes in Pelvic Tilt have a substantial effect on the functional orientation of the acetabulum. The aim of this study was to quantify the changes in sagittal Pelvic position between three functional postures.MethodologyPre-operatively, 1,517 total hip replacement patients had their Pelvic Tilt measured in 3 functional positions – standing, supine and flexed seated (point when patients initiate rising from a seated position). Lateral radiographs were used to define the Pelvic Tilt in the standing and flexed seated positions. Pelvic Tilt was defined as the angle between a vertical reference line and the anterior Pelvic plane (defined by the line joining both anterior superior iliac spines and the pubic symphysis). In the supine position Pelvic Tilt was defined as the angle between a horizontal reference line and the anterior Pelvic plane. Supine Pelvic Tilt was meas...

  • Pelvic Tilt IN THE STANDING, SUPINE AND SEATED POSITIONS
    2018
    Co-Authors: J Pierrepont, L Walter, B. Miles, E Marel, J Bare, M Solomon, S Mcmahon, A Shimmin
    Abstract:

    IntroductionThe pelvis is not a static structure. It rotates in the sagittal plane depending upon the activity being performed. These dynamic changes in Pelvic Tilt have a substantial effect on the...

  • The effect of seated Pelvic Tilt on posterior edge-loading in total hip arthroplasty: A finite element investigation.
    Proceedings of the Institution of Mechanical Engineers. Part H Journal of engineering in medicine, 2018
    Co-Authors: J Pierrepont, Long Yang, Jevan Arulampalam, Catherine Zoe Stambouzou, Brad Miles
    Abstract:

    Edge-loading of a ceramic-on-ceramic total hip replacement can lead to reproducible squeaking and revision. A patient's functional acetabular cup orientation, driven by their Pelvic Tilt, has been shown to be a significant factor in squeaking during hip flexion. The aim of this study was to investigate the effect of seated Pelvic Tilt on the contact mechanics at the ceramic bearing surface. A finite element model of a ceramic-on-ceramic total hip replacement was created. The cup was orientated at 40° inclination and 15° anteversion relative to the anterior Pelvic plane. The stem was flexed 90° to replicate sitting in a chair. The model was loaded using data from in vivo measurements taken during a sit-to-stand activity. The pelvis was modelled in seven different sagittal positions, ranging from -30° to 30° of Pelvic Tilt, where a positive value denotes anterior Pelvic Tilt. Three different head sizes were investigated: 32, 36 and 40 mm. The maximum contact pressure and contact patch to rim distance were determined for each of the 21 simulations. Edge-loading (contact patch to rim distance 

  • THE CLINICAL RELEVANCE OF FUNCTIONAL Pelvic Tilt: A PRE-OPERATIVE ANALYSIS OF 1517 PATIENTS
    Journal of Bone and Joint Surgery-british Volume, 2017
    Co-Authors: R. Reitman, J Pierrepont, S Mcmahon, Len Walter, Andrew Shimmin, E. Kerzhner
    Abstract:

    Introduction The pelvis is not a static structure. It rotates in the sagittal plane depending upon the activity being performed. These dynamic changes in Pelvic Tilt have a substantial effect on the functional orientation of the acetabulum. The aim of this study was to quantify the changes in sagittal Pelvic position between three functional postures. Methodology Pre-operatively, 1,517 total hip replacement patients had their Pelvic Tilt measured in 3 functional positions – standing, supine and flexed seated (point when patients initiate rising from a seated position). Lateral radiographs were used to define the Pelvic Tilt in the standing and flexed seated positions. Pelvic Tilt was defined as the angle between a vertical reference line and the anterior Pelvic plane (defined by the line joining both anterior superior iliac spines and the pubic symphysis). In the supine position Pelvic Tilt was defined as the angle between a horizontal reference line and the anterior Pelvic plane. Supine Pelvic Tilt was measured from computed tomography. Results The mean supine Pelvic Tilt was 4.2°, with a range of −20.5° to 24.5°. The mean standing Pelvic Tilt was −1.3°, with a range of −30.2° to 27.9°. Mean Pelvic Tilt in the flexed seated position was 0.6°, with a range of −42.0° to 41.3°. The mean absolute change from supine to stand, and supine to flexed seated was 6.0° (SD = 3.8°) and 10.7° (SD = 8.1°) respectively. 6% of patients rotated posteriorly by more than 13° from supine to stand, consequently putting them at risk of excessive functional anteversion in extension. 11% of patients rotated anteriorly by more than 13° from supine to seated, consequently retroverting their cup and putting them at risk in flexion. Therefore, 17% of patients had sagittal Pelvic rotations that could lead to functional cup malorientation even with a supposedly ideal orientation of 40°/20°. Factoring in an intraoperative delivery error of ± 5° extends this risk to 51% of patients.

  • Variation in functional Pelvic Tilt in patients undergoing total hip arthroplasty
    The bone & joint journal, 2017
    Co-Authors: J Pierrepont, J Bare, S Mcmahon, G. Hawdon, Brad Miles, B. O’ Connor, Len Walter, Ed Marel, Michael Solomon, Andrew Shimmin
    Abstract:

    Aims The pelvis rotates in the sagittal plane during daily activities. These rotations have a direct effect on the functional orientation of the acetabulum. The aim of this study was to quantify changes in Pelvic Tilt between different functional positions. Patients and Methods Pre-operatively, Pelvic Tilt was measured in 1517 patients undergoing total hip arthroplasty (THA) in three functional positions – supine, standing and flexed seated (the moment when patients initiate rising from a seated position). Supine Pelvic Tilt was measured from CT scans, standing and flexed seated Pelvic Tilts were measured from standardised lateral radiographs. Anterior Pelvic Tilt was assigned a positive value. Results The mean Pelvic Tilt was 4.2° (-20.5° to 24.5°), -1.3° (-30.2° to 27.9°) and 0.6° (-42.0° to 41.3°) in the three positions, respectively. The mean sagittal Pelvic rotation from supine to standing was -5.5° (-21.8° to 8.4°), from supine to flexed seated was -3.7° (-48.3° to 38.6°) and from standing to flexed seated was 1.8° (-51.8° to 39.5°). In 259 patients (17%), the extent of sagittal Pelvic rotation could lead to functional malorientation of the acetabular component. Factoring in an intra-operative delivery error of ± 5° extends this risk to 51% of patients. Conclusion Planning and measurement of the intended position of the acetabular component in the supine position may fail to predict clinically significant changes in its orientation during functional activities, as a consequence of individual Pelvic kinematics. Optimal orientation is patient-specific and requires an evaluation of functional Pelvic Tilt pre-operatively. Cite this article: Bone Joint J 2017;99-B:184–91.

Pedro A. López-miñarro - One of the best experts on this subject based on the ideXlab platform.

  • COMPARISON OF SAGITTAL SPINAL CURVATURES AND Pelvic Tilt IN HIGHLY TRAINED ATHLETES FROM DIFFERENT SPORT DISCIPLINES
    Kinesiology, 2017
    Co-Authors: Pedro A. López-miñarro, Fernando Alacid, Raquel Vaquero-cristóbal, Manuel Isorna, José M. Muyor
    Abstract:

    The aim of this study was to compare the thoracic and lumbar curvatures and Pelvic Tilt in relaxed standing and maximal trunk flexion among highlytrained young athletes from three different sports disciplines. Thirty-two male canoeists, 30 male kayakers and 24 male tennis players were recruited for the study. The Spinal Mouse® system was used to measure the thoracic and lumbar sagittal spinal curvatures and Pelvic Tilt in relaxed standing and maximal trunk flexion in sitting with the flexed (McRae & Wright test) and extended knees (sit-and-reach test). Significant differences were found in maximal trunk flexion tests among athletes. Kayakers and canoeists showed increased anterior Pelvic Tilt compared to tennis players in the McRae & Wright (p

  • SAGITTAL SPINAL CURVATURES AND Pelvic Tilt OF FEMALE DANCERS IN STANDING POSTURE
    British Journal of Sports Medicine, 2014
    Co-Authors: Francisco Esparza-ros, Fernando Alacid, Raquel Vaquero-cristóbal, E Martínez-ruiz, Pedro A. López-miñarro
    Abstract:

    Background A good control of the spinal posture may induce greater ability to change spinal angles in several positions. The spinal posture influences vertebral loading during daily activities. Neutral postures have been associated to lower spinal forces in the intervertebral joints. Objective To compare the spinal posture and Pelvic Tilt between relaxed standing and active alignment while standing in elementary education dancers. Design Comparative study. Setting Dance Conservatory professional. The sample included dance students of 4th year. Participants 46 female dancers (mean±SD, age: 12.07±1.01 years-old) were recruited for this study. All participants had at less 4 years of experience in the Dance Conservatory. Risk factor assessment Not applicable. Main outcome measurements Thoracic kyphosis, lumbar lordosis and Pelvic Tilt were measured in relaxed standing and during active alignment of spinal curvatures using a Spinal Mouse ® . Results Thoracic and lumbar curvatures and Pelvic Tilt values while relaxed standing were 18.72±11.11°, -25.52±7.14° and 19.52±5.10°, respectively. Mean values in the active alignment were: 4.96±13.54°, -3.76±12.12° and 4.57±7.06°, respectively. Significant differences between both postures were found in the thoracic (t=6.39; P Conclusions Dance is associated with a large control of spinal posture in standing position. Dance training is related to a great curvature change when active alignment of spinal curves is required. This control of spinal curvatures may reduce the risk of injury in dance and daily activities.

  • Acute Effects of Hamstring Stretching on Sagittal Spinal Curvatures and Pelvic Tilt
    Journal of Human Kinetics, 2012
    Co-Authors: Pedro A. López-miñarro, José M. Muyor, Felipe Belmonte, Fernando Alacid
    Abstract:

    The aim of this study was to determine acute effects of hamstring stretching in thoracic and lumbar spinal curvatures and Pelvic Tilt. Fifty-five adults (29.24 ± 7.41 years) were recruited for this study. Subjects performed a hamstring stretching protocol consisting of four exercises. The session consisted of 3 sets of each exercise and subjects held the position for 20 seconds with a 30-second rest period between sets and exercises. Thoracic and lumbar spinal angles and Pelvic Tilt were measured with a SpinalMouse in relaxed standing, sit-and-reach test and Macrae & Wright position. Hamstring extensibility was determined by active straight leg raise test and sit-and-reach score. All measures were performed before and immediately after the hamstring stretching protocol. Active straight leg raise angle and sitand-reach score significantly improved immediately after the stretching protocol (p

Stephan Tohtz - One of the best experts on this subject based on the ideXlab platform.

  • Influence of Pelvic Tilt on functional acetabular orientation.
    Technology and health care : official journal of the European Society for Engineering and Medicine, 2017
    Co-Authors: Robert K. Zahn, Sarah Grotjohann, Matthias Pumberger, Heiko Ramm, Stefan Zachow, Michael Putzier, Carsten Perka, Stephan Tohtz
    Abstract:

    BACKGROUND Pelvic Tilt influences acetabular orientation (AO). Anatomical AO can be measured in relation to the anterior Pelvic plane (APP), functional AO can be calculated relative to table's plane. OBJECTIVE To assess to what extent functional AO is determined by Pelvic Tilt and if APP and table plane give equal information for correct AO. METHODS AO was evaluated by computed tomography (CT) scans of 138 patients. Pelvic Tilt, anatomical and functional AO were measured, differences between the two reference planes were calculated. RESULTS Anatomical and functional acetabular anteversion (AA) were found to be different in 21% of individuals with an enhanced extent of Pelvic Tilt. Functional AA was increased compared to anatomical AA at high posterior Pelvic Tilt (p < 0.001). Enlarged anterior Tilting of the pelvis reduced APP-related AA (p < 0.002). Anatomical AA positively correlated with Pelvic Tilt, particularly in females (p < 0.01, correlation coefficient = 0.698, R2 = 0.523). CONCLUSIONS APP and table plane do not provide equal information about AO at enhanced Pelvic Tilt. Functional orientation of the acetabulum is dependent on Pelvic Tilt, which itself is influenced by anatomical AA and should therefore be analyzed for precise AO.

  • Pelvic Tilt compensates for increased acetabular anteversion
    International Orthopaedics, 2016
    Co-Authors: Robert K. Zahn, Sarah Grotjohann, Heiko Ramm, Stefan Zachow, Michael Putzier, Carsten Perka, Stephan Tohtz
    Abstract:

    Purpose Pelvic Tilt determines functional orientation of the acetabulum. In this study, we investigated the interaction of Pelvic Tilt and functional acetabular anteversion (AA) in supine position. Methods Pelvic Tilt and AA of 138 individuals were measured by computed tomography (CT). AA was calculated in relation to the anterior Pelvic plane (APP) and relative to the table plane. We analysed these parameters for gender-specific and age-related differences. Results The mean Pelvic Tilt was -0.1 ± 5.5°. Pelvic sagittal rotation displayed no gender nor age related differences. Females showed higher angles of AA compared with males (20.0° vs 17.2°, p  

  • Pelvic Tilt compensates for increased acetabular anteversion
    International orthopaedics, 2015
    Co-Authors: Robert K. Zahn, Sarah Grotjohann, Heiko Ramm, Stefan Zachow, Michael Putzier, Carsten Perka, Stephan Tohtz
    Abstract:

    Purpose Pelvic Tilt determines functional orientation of the acetabulum. In this study, we investigated the interaction of Pelvic Tilt and functional acetabular anteversion (AA) in supine position.

Anna Gogola - One of the best experts on this subject based on the ideXlab platform.

  • The impact of core muscles training on the range of anterior Pelvic Tilt in subjects with increased stiffness of the hamstrings
    Human Movement Science, 2017
    Co-Authors: Michał Kuszewski, Rafał Gnat, Anna Gogola
    Abstract:

    The aim of this study is to verify the hypotheses that muscular coordination training of the core region in subjects showing increased hamstring stiffness results in an increase in anterior Pelvic Tilt and that there is a correlation between hamstring stiffness and anterior Pelvic Tilt. The two-group, non-blinded experimental controlled trial with three repeated measurements of the dependent variables. The experimental group received muscular coordination training during a period of two weeks, control group - no training. Thirty generally healthy subjects (9 women) were randomly assigned to the two equal groups. Passive knee extension test (hamstring stiffness); the range of anterior Pelvic Tilt (as measured in neutral standing position and during forward bending of the trunk). A significant decrease in the level of hamstring stiffness was recorded in the experimental group accompanied by an increase in anterior Pelvic Tilt. No significant changes were observed in the control group. There was a significant, negative, and moderate correlation between hamstring stiffness and anterior Pelvic Tilt with forward bending of the trunk).