Yohei Ohyama1, Yukihide Minoda2, Yoichi Ohta1, Ryo Sugama1, Susumu Takemura3, Hiroaki Nakamura1. 1. Department of Orthopaedic Surgery, Osaka Metropolitan University Graduate School of Medicine, 1-4-3 Asahi-Machi Abeno-Ku Osaka-City, Osaka, 545-8585, Japan. 2. Department of Orthopaedic Surgery, Osaka Metropolitan University Graduate School of Medicine, 1-4-3 Asahi-Machi Abeno-Ku Osaka-City, Osaka, 545-8585, Japan. yminoda@omu.ac.jp. 3. Department of Orthopedic Surgery, Osaka Rosai Hospital, 1179-3 Nagasone-Cho Sakai-City, Osaka, 591-8025, Japan.
Abstract
INTRODUCTION: It is clinically important to analyze the initial contact state between an implant and femoral cortical bone as it affects clinical outcomes, such as stress shielding, stem subsidence, thigh pain, and patient-reported outcomes after total hip arthroplasty. Whether the initial contact state of a double-tapered fully hydroxyapatite (HA)-coated stem is achieved with the preserved cancellous or cortical bone remains to be established. This study aimed to compare the contact area with the femoral cortical bone between a double-tapered fully HA-coated stem (HA group) and a tapered wedge cementless stem (TW group) using three-dimensional computed tomography (3DCT)-based templating software. MATERIALS AND METHODS: Forty-seven total hip arthroplasties in the HA and TW groups each were retrospectively analyzed. The contact area between the implant and femoral cortical bone in the whole stem and at each Gruen zone was measured using density mapping with 3DCT-based templating software. RESULTS: The demographic data were not significantly different between the two groups. The contact area in the whole stem area was lower in the HA group (HA 5.4 ± 1.8% vs. TW 9.0 ± 4.8%, p < 0.01). The HA group had a lower contact area in zone 2 (HA 6.7 ± 6.5% vs. TW 15.6 ± 10.8%, p < 0.01) and zone 6 (HA 1.8 ± 3.5% vs. TW 6.3 ± 3.6%, p < 0.01) than the TW group. The implant type (β = 0.41, p < 0.01) and stem coronal alignment (β = - 0.29, p < 0.01) were significant predictors of the contact area in the whole stem area in a multiple regression analysis (adjusted R2 = 0.27, p < 0.01). CONCLUSION: The contact area of the double-tapered fully HA-coated stem was significantly lower than that of the tapered wedge cementless stem.
INTRODUCTION: It is clinically important to analyze the initial contact state between an implant and femoral cortical bone as it affects clinical outcomes, such as stress shielding, stem subsidence, thigh pain, and patient-reported outcomes after total hip arthroplasty. Whether the initial contact state of a double-tapered fully hydroxyapatite (HA)-coated stem is achieved with the preserved cancellous or cortical bone remains to be established. This study aimed to compare the contact area with the femoral cortical bone between a double-tapered fully HA-coated stem (HA group) and a tapered wedge cementless stem (TW group) using three-dimensional computed tomography (3DCT)-based templating software. MATERIALS AND METHODS: Forty-seven total hip arthroplasties in the HA and TW groups each were retrospectively analyzed. The contact area between the implant and femoral cortical bone in the whole stem and at each Gruen zone was measured using density mapping with 3DCT-based templating software. RESULTS: The demographic data were not significantly different between the two groups. The contact area in the whole stem area was lower in the HA group (HA 5.4 ± 1.8% vs. TW 9.0 ± 4.8%, p < 0.01). The HA group had a lower contact area in zone 2 (HA 6.7 ± 6.5% vs. TW 15.6 ± 10.8%, p < 0.01) and zone 6 (HA 1.8 ± 3.5% vs. TW 6.3 ± 3.6%, p < 0.01) than the TW group. The implant type (β = 0.41, p < 0.01) and stem coronal alignment (β = - 0.29, p < 0.01) were significant predictors of the contact area in the whole stem area in a multiple regression analysis (adjusted R2 = 0.27, p < 0.01). CONCLUSION: The contact area of the double-tapered fully HA-coated stem was significantly lower than that of the tapered wedge cementless stem.
Authors: Silje Marie Melbye; Sofie Cecilia Dietrich Haug; Anne Marie Fenstad; Ove Furnes; Jan-Erik Gjertsen; Geir Hallan Journal: Clin Orthop Relat Res Date: 2021-10-01 Impact factor: 4.755
Authors: Charles Rivière; Guido Grappiolo; Charles A Engh; Jean-Pierre Vidalain; Antonia-F Chen; Nicolas Boehler; Jihad Matta; Pascal-André Vendittoli Journal: EFORT Open Rev Date: 2018-02-26