Hip Range of Motion During Daily Activities in Patients with Posterior Pelvic Tilt from Supine to Standing Position Satoru Tamura,1 Hidenobu Miki,2 Kosuke Tsuda,1 Masaki Takao,3 Asaki Hattori,4 Naoki Suzuki,4 Kazuo Yonenobu,5 Nobuhiko Sugano1 1
Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Suita, Japan, 2Department of Orthopaedic Surgery, Osaka National Hospital, Osaka, Japan, 3Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Suita, Japan, 4Institute for High Dimensional Medical Imaging, Jikei University School of Medicine, Tokyo, Japan, 5Graduate School of Health Care Sciences, Jikei Institute, Osaka, Japan Received 16 May 2013; accepted 4 December 2014 Published online 8 February 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/jor.22799
ABSTRACT: In most patients with hip disorders, the anterior pelvic plane (APP) sagittal tilt does not change from supine to standing position. However, in some patients, APP sagittal tilt changes more than 10˚ posteriorly from supine to standing position. The purpose of this study was to both examine APP sagittal tilt and investigate the hip flexion and extension range of motion (ROM) required during daily activities in these atypical patients. Patient-specific 4-dimensional (4D) motion analysis was performed for 50 hips from 44 patients who had undergone total hip arthroplasty. All patients divided into two categories, such as atypical patients for whom the pelvis tilted more than 10˚ posteriorly from supine to standing position preoperatively (19 hips from 18 patients) and the remaining typical patients (31 hips from 26 patients). The required hip flexion and extension angles did not differ significantly between atypical patients and typical patients. In conclusion, the hip flexion ROM during deep bending activities and hip extension ROM during extension activities required in those atypical patients with pelvic tilt more than 10˚ backward from supine to standing position did not shift in the direction of extension. ß 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:542–547, 2015. Keywords: pelvic tilt; total hip arthroplasty; motion analysis
In total hip arthroplasty (THA), cup mal-alignment increases the risk of implant impingement, which leads to postoperative complications such as dislocation, cup loosening and breakage or accelerated wear of the cup liner.1–3 When cup alignment is measured, the pelvic position or coordinates is need to be defined. Classically, cup orientation has been usually measured on supine antero-posterior (AP) radiographs, because the rim of most cups is easy to detect on AP radiographs and this modality is usually used for routine follow-up examination. On the other hand, Lewinnek et al. thought that the individual pelvic position is variable in the supine position and tried to adjust the X-ray beam direction perpendicular to the anterior pelvic plane (APP) to measure cup orientation.4 However, few have followed this technique of APP adjustment to take AP radiographs for cup angle measurements, probably because APP is conceptually flat in the supine position in most patients. On the other hand, many reports since the advent of CT-based navigation have noted that APP sagittal tilt to the body axis shows individual variability.5–7 Moreover, some patients with hip disorders show more than 10˚ of difference in APP sagittal tilt between supine and standing positions, although 90% of patients show 10˚ or less of difference.8,9 These atypical patients whose pelvis tilts more than 10˚ backward from supine to standing position are reportedly often elderly and show lumbar degeneration such as degenerative disc diseases
and degenerative spondylolisthesis, or compression fractures.7,10–13 With such patients, there is a concern that even if the cup is placed in a target zone in a supine pelvic position, the risk of posterior impingement and anterior dislocation may increase after THA. Some authors have recommended decreasing cup inclination and anteversion in the supine pelvis in these atypical patients.14,15 If the hip flexion range of motion (ROM) required during deep bending activities in those patients shifts in the direction of extension according the extent of further posterior pelvic tilt when standing, such recommendations may be reasonable. Otherwise, this may increase the risks of anterior impingement and posterior dislocation. Clarification of the hip flexion ROM during deep bending activities and extension ROM during hip extension activities required in these atypical patients is therefore essential for proper cup placement, but no studies have yet reported on this issue. The present study therefore examined the following: 1) postoperative APP sagittal tilt in standing position, during walking and during sitting on a chair; and 2) differences in hip flexion ROM required during walking and picking up an object while seated on a chair, plus extension ROM required during walking, stretching the Achilles tendon and bending backwards between those atypical patients and standard patients.
METHODS Correspondence to: Nobuhiko Sugano, 2-2, Yamadaoka, Suita, Osaka 5650871, Japan. (T: þ81-6-6879-3271; F: þ81-6-6879-3272; E-mail: [email protected]) # 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
542
JOURNAL OF ORTHOPAEDIC RESEARCH APRIL 2015
All study protocols were approved by our institutional review board. Motion analysis was performed after THA using a patient-specific 4-dimensional (4D) motion analysis system in 50 hips from 44 patients who underwent primary cementless THA for osteoarthritis due to hip dysplasia between February 2007
HIP ROM AND PELVIC TILT
and February 2010. All THAs were performed through a posterolateral approach. Mean age at the time of THA was 63.7 11.5 years (range, 46 to 86 years). Mean duration from THA to 4D motion analysis was 1.8 3.6 months (range, 0.5–24 months). No complications that influenced the daily activities of patients, including infection, fracture, deep venous thrombosis, or dislocation, were encountered. No precautions regarding daily activities were given. Standard AP radiographs of the pelvis in supine and standing positions were obtained preoperatively as a routine preoperative examination. The focus of the central Xray beam was over the superior margin of the pubic tubercle, perpendicular to the line between bilateral anterior superior iliac spines (ASISs). Each patient was asked to stand in a comfortable posture while holding a supporting front or side bar when the standing radiographs were taken. Computed tomography (CT) images from the pelvis to the knee were obtained in all patients for CT-based navigation. Cup alignment was determined during preoperative planning according to stem anteversion while keeping radiographic cup inclination always aimed at 40˚. Our target cup anteversion is shown in Table 1. This technique was a simplified version of the combined anteversion theory described previously.16 This combination of cup and stem orientation provides implant-implant ROM greater than 120˚ in flexion, 40˚ in extension, 40˚ in abduction, 40˚ in external rotation and 40˚ in internal rotation at 90˚ of hip flexion.17,18 Digitally reconstructed radiography (DRR) of the pelvis was made on the sagittal plane from the preoperative CT images using 3D viewer software (3D Template; Kyocera Medical, Osaka, Japan). The APP through the most anterior aspect of the pubic tubercle and bilateral ASISs was used to measure APP sagittal tilt, which was defined as the angle between the APP and the vertical axis on the sagittal plane DRR. Preoperative APP sagittal tilt on the standing radiograph was calculated using a 2D–3D matching technique with the preoperative CT images and preoperative AP radiographs, as reported previously.8 The pelvis was rotated on the 3D viewer to match the pelvis on the AP DRR with that on the standing AP radiograph. APP sagittal tilt was then measured on the sagittal plane DRR. A positive APP sagittal tilt indicated anterior tilting (or flexion) of the pelvis as defined in previous studies.6–9,14 In all patients, the mean preoperative APP sagittal tilts in supine position was 1.3 11.6˚ (range, 30.0˚–26.0˚) and that in standing position was 8.9 18.0˚ (range, 49.0˚–24.0˚). Patients in whom the APP sagittal tilt changed more than 10˚ posteriorly from supine AP radiograph to standing AP radiograph were classified as Group P; the remaining patients were classified as Group C. Group P consisted of 18 patients (19
Table 1. Target Radiographic According to Stem Anteversion Stem anteversion (˚) 45 Stem anteversion
Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, Suita, Japan, 2Department of Orthopaedic Surgery, Osaka National Hospital, Osaka, Japan, 3Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Suita, Japan, 4Institute for High Dimensional Medical Imaging, Jikei University School of Medicine, Tokyo, Japan, 5Graduate School of Health Care Sciences, Jikei Institute, Osaka, Japan Received 16 May 2013; accepted 4 December 2014 Published online 8 February 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/jor.22799
ABSTRACT: In most patients with hip disorders, the anterior pelvic plane (APP) sagittal tilt does not change from supine to standing position. However, in some patients, APP sagittal tilt changes more than 10˚ posteriorly from supine to standing position. The purpose of this study was to both examine APP sagittal tilt and investigate the hip flexion and extension range of motion (ROM) required during daily activities in these atypical patients. Patient-specific 4-dimensional (4D) motion analysis was performed for 50 hips from 44 patients who had undergone total hip arthroplasty. All patients divided into two categories, such as atypical patients for whom the pelvis tilted more than 10˚ posteriorly from supine to standing position preoperatively (19 hips from 18 patients) and the remaining typical patients (31 hips from 26 patients). The required hip flexion and extension angles did not differ significantly between atypical patients and typical patients. In conclusion, the hip flexion ROM during deep bending activities and hip extension ROM during extension activities required in those atypical patients with pelvic tilt more than 10˚ backward from supine to standing position did not shift in the direction of extension. ß 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:542–547, 2015. Keywords: pelvic tilt; total hip arthroplasty; motion analysis
In total hip arthroplasty (THA), cup mal-alignment increases the risk of implant impingement, which leads to postoperative complications such as dislocation, cup loosening and breakage or accelerated wear of the cup liner.1–3 When cup alignment is measured, the pelvic position or coordinates is need to be defined. Classically, cup orientation has been usually measured on supine antero-posterior (AP) radiographs, because the rim of most cups is easy to detect on AP radiographs and this modality is usually used for routine follow-up examination. On the other hand, Lewinnek et al. thought that the individual pelvic position is variable in the supine position and tried to adjust the X-ray beam direction perpendicular to the anterior pelvic plane (APP) to measure cup orientation.4 However, few have followed this technique of APP adjustment to take AP radiographs for cup angle measurements, probably because APP is conceptually flat in the supine position in most patients. On the other hand, many reports since the advent of CT-based navigation have noted that APP sagittal tilt to the body axis shows individual variability.5–7 Moreover, some patients with hip disorders show more than 10˚ of difference in APP sagittal tilt between supine and standing positions, although 90% of patients show 10˚ or less of difference.8,9 These atypical patients whose pelvis tilts more than 10˚ backward from supine to standing position are reportedly often elderly and show lumbar degeneration such as degenerative disc diseases
and degenerative spondylolisthesis, or compression fractures.7,10–13 With such patients, there is a concern that even if the cup is placed in a target zone in a supine pelvic position, the risk of posterior impingement and anterior dislocation may increase after THA. Some authors have recommended decreasing cup inclination and anteversion in the supine pelvis in these atypical patients.14,15 If the hip flexion range of motion (ROM) required during deep bending activities in those patients shifts in the direction of extension according the extent of further posterior pelvic tilt when standing, such recommendations may be reasonable. Otherwise, this may increase the risks of anterior impingement and posterior dislocation. Clarification of the hip flexion ROM during deep bending activities and extension ROM during hip extension activities required in these atypical patients is therefore essential for proper cup placement, but no studies have yet reported on this issue. The present study therefore examined the following: 1) postoperative APP sagittal tilt in standing position, during walking and during sitting on a chair; and 2) differences in hip flexion ROM required during walking and picking up an object while seated on a chair, plus extension ROM required during walking, stretching the Achilles tendon and bending backwards between those atypical patients and standard patients.
METHODS Correspondence to: Nobuhiko Sugano, 2-2, Yamadaoka, Suita, Osaka 5650871, Japan. (T: þ81-6-6879-3271; F: þ81-6-6879-3272; E-mail: [email protected]) # 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
542
JOURNAL OF ORTHOPAEDIC RESEARCH APRIL 2015
All study protocols were approved by our institutional review board. Motion analysis was performed after THA using a patient-specific 4-dimensional (4D) motion analysis system in 50 hips from 44 patients who underwent primary cementless THA for osteoarthritis due to hip dysplasia between February 2007
HIP ROM AND PELVIC TILT
and February 2010. All THAs were performed through a posterolateral approach. Mean age at the time of THA was 63.7 11.5 years (range, 46 to 86 years). Mean duration from THA to 4D motion analysis was 1.8 3.6 months (range, 0.5–24 months). No complications that influenced the daily activities of patients, including infection, fracture, deep venous thrombosis, or dislocation, were encountered. No precautions regarding daily activities were given. Standard AP radiographs of the pelvis in supine and standing positions were obtained preoperatively as a routine preoperative examination. The focus of the central Xray beam was over the superior margin of the pubic tubercle, perpendicular to the line between bilateral anterior superior iliac spines (ASISs). Each patient was asked to stand in a comfortable posture while holding a supporting front or side bar when the standing radiographs were taken. Computed tomography (CT) images from the pelvis to the knee were obtained in all patients for CT-based navigation. Cup alignment was determined during preoperative planning according to stem anteversion while keeping radiographic cup inclination always aimed at 40˚. Our target cup anteversion is shown in Table 1. This technique was a simplified version of the combined anteversion theory described previously.16 This combination of cup and stem orientation provides implant-implant ROM greater than 120˚ in flexion, 40˚ in extension, 40˚ in abduction, 40˚ in external rotation and 40˚ in internal rotation at 90˚ of hip flexion.17,18 Digitally reconstructed radiography (DRR) of the pelvis was made on the sagittal plane from the preoperative CT images using 3D viewer software (3D Template; Kyocera Medical, Osaka, Japan). The APP through the most anterior aspect of the pubic tubercle and bilateral ASISs was used to measure APP sagittal tilt, which was defined as the angle between the APP and the vertical axis on the sagittal plane DRR. Preoperative APP sagittal tilt on the standing radiograph was calculated using a 2D–3D matching technique with the preoperative CT images and preoperative AP radiographs, as reported previously.8 The pelvis was rotated on the 3D viewer to match the pelvis on the AP DRR with that on the standing AP radiograph. APP sagittal tilt was then measured on the sagittal plane DRR. A positive APP sagittal tilt indicated anterior tilting (or flexion) of the pelvis as defined in previous studies.6–9,14 In all patients, the mean preoperative APP sagittal tilts in supine position was 1.3 11.6˚ (range, 30.0˚–26.0˚) and that in standing position was 8.9 18.0˚ (range, 49.0˚–24.0˚). Patients in whom the APP sagittal tilt changed more than 10˚ posteriorly from supine AP radiograph to standing AP radiograph were classified as Group P; the remaining patients were classified as Group C. Group P consisted of 18 patients (19
Table 1. Target Radiographic According to Stem Anteversion Stem anteversion (˚) 45 Stem anteversion
