Postoperative radiographic evaluation and simulation study for optimal cup placement in high-hip centre total hip arthroplasty

Abstract

Background: Achieving favourable outcomes in high-hip centre reconstruction in hip dysplasia requires the optimal cup height and size, which can provide sufficient bone coverage for stable cup fixation that fits the anteroposterior acetabular rim without increasing the cup height more than necessary. Methods: We retrospectively reviewed 214 patients who underwent primary total hip arthroplasty (THA) and identified 30 hips with Crowe II ( n = 15) or III ( n = 15) developmental dysplasia of the hip (DDH). We measured the cup-centre-edge angle (cup-CE) and the vertical and horizontal distances from the teardrop. In a simulation study, we examined the cup-CE and optimal cup size by changing the cup height in 5-mm increments over a distance of 15–40 mm above the inter-teardrop line using a 3-dimensional template system. Results: Postoperative radiographic evaluation revealed a mean cup-CE of 19.9° in Crowe II hips and 15.2° in Crowe III hips; the respective mean vertical distances were 26.6 mm and 27.6 mm ( p = 0.511). There was no evidence of cup loosening or lateralisation at a minimum of 7 years (7–11 years) follow-up. Simulation showed that the hip centre needed to be elevated to 20 mm to acquire a cup-CE of more than 0°. More than 10° of cup-CE could be expected by elevating the hip centre to 25 mm in both Crowe II and III. Conclusions: Even in severe DDH, a high-hip centre positioned approximately 25 mm superior to the inter-teardrop line was sufficient to achieve optimal bone coverage, which could lead to more secure cup fixation.

Acetabular Revision Arthroplasty Based on 3-Dimensional Reconstruction Technology Using Jumbo Cups

“…Increasing the contact area between the acetabular cup and the host bone can ensure good initial stability, which is a crucial success factor of hip arthroplasty revision. CC is usually used to evaluate this contact area and in DDH hip replacement ( Yang et al, 2017 ; Liu et al, 2018 ; Mou et al, 2020 ; Takasago et al, 2021 ). Generally, insufficient CC will increase the stress at the bone cup interface, thus increasing the probability of mechanical failure ( Apostu et al, 2018 ; Zuo et al, 2021 ).…”

Computer simulation study of cementless cup placement for dysplastic hip osteoarthritis using subluxation percentage of Crowe classification

“…15 The anteroposterior diameters of the true acetabulum were measured using CT horizontal section, and the cup size was chosen to best accommodate the true acetabulum from a range of 42-66 mm at 2-mm intervals. The 3D cup template was placed based on previous reports, 10,14 at an inclination of 40°and anteversion of 20°in a radiographic definition, as medial as possible, adjacent to the medial wall of the pelvis to obtain maximum bone coverage. The AHC was defined as 15 mm above the inter-teardrop line, 16,17 and cup placement was simulated at the AHC and 10-mm HHC (Figure 1).…”

“…Although certain simulation studies have reported cup coverage in THA for DDH, most have classified Crowe II and III into one collective group, and few studies have quantitatively evaluated subluxation. [12][13][14] We hypothesized that a boundary exists, indicating sufficient coverage to fix a cementless cup between Crowe II and III. We consider this to be a useful indicator for planning cementless cup placement, especially to evaluate the relationship between the hip's subluxation percentage according to the Crowe classification and cup coverage.…”

How to Develope a Novel 3D Printed Integral Customized Anatomical Acetabular Prosthesis in Hip Arthroplasty for Crowe Type II and III Developmental Dysplasia of the Hip?

“…It has been accepted that high placement of hip rotation center could simply the operation, increase the coverage rate of acetabular prosthesis, and improve the initial stability of the acetabular cup. However, it is impossible to avoid the improvement of biological stress of the hip joint , the increase of wear rate of the prosthesis, the secondary complications of lower limb length discrepancy, impingement, gluteus medius fatigue, gait changes, dislocation due to the upward migration of the hip rotation center (7)(8)(9). Currently, more and more scholars (6,10,11) proposed anatomical restoration of rotation center in THA for patients with Crowe type II/III DDH, which is beneficial to balance the stress of ligaments and muscles surrounding the hip joint, reduce the wear rate and loosening of the hip prosthesis, whereas it is difficult to restore the hip rotation center and reconstruct the bone defect during the operation.…”