Preoperative templating is an important part of a THA. The ability to accurately determine magnification of the hip on the radiograph and apply identical magnification to the radiograph and template will improve accuracy of preoperative templating of THA. We designed a templating method using a new way of determining the hip magnification with a linear relationship between magnification of the hip and the reference object on top of the pubis symphysis; the relationship was determined on 50 radiographs. We then compared our method with two other templating methods: an analog method assuming an average hip magnification of 15% and a digital method determining the hip magnification with a one-to-one relationship between the reference object and the hip. All methods were reproducible. Uniform undersizing occurred when templating with the digital method based on the oneto-one relationship; the analog method best predicted the implanted prosthesis size, closely followed by our new digital templating method; the new method will be particularly applicable for preoperative THA when analog methods are replaced by digital methods.
Total hip arthroplasty in young patients is associated with high failure rates and the best option for this demanding group of patients remains controversial. We report the long-term results of 73 consecutive Zweymüller total hip arthroplasties with a titanium threaded cup and a polyethylene insert in 67 patients aged under 50 years at the time of surgery (mean 43 years, range 23-49). Independent assessment was performed clinically and radiographically, and Kaplan-Meier analysis was used to determine survival for different end-points. Three hips were revised for septic loosening, three cups for aseptic loosening and one hip because of a periprosthetic fracture. Three patients (3 hips) died and seven patients (8 hips) were lost to radiographic follow-up without any reoperation. The mean follow-up was 17.5 (15-21) years and the mean HHS was 90 (52-100). Survival with an end-point of revision for any reason was 89% (95% C.I. 85-93) and of revision for aseptic loosening was 94% (C.I. 95-99) at 17 years. Zweymüller total hip arthroplasty with a titanium threaded cup and a polyethylene insert showed good long-term results, even in this group of young patients.
Purpose To optimize our standard full-spine radiography with respect to diagnostic quality and dose. Methods A phantom study was performed to establish an optimal posterior-anterior view (PA) full spine protocol having the lowest dose with non-inferior quality compared to standard. We then applied this protocol in 40 pediatric patients (group B). The radiographs were scored on six criteria by a pediatric radiologist and orthopedist and compared to the scores of 40 PA full spine radiographs performed in 2013 with standard protocol (group A). Radiation dose was assessed by dose area product (DAP) and effective dose (E). Statistical analysis included independent samples t test, Mann-Whitney U test and intra-class correlation coefficient (ICC). Results An optimized protocol was defined (0.2 mm Cu filter, 0.87 relative exposure, with grid). Mean age was 13.3 ± 1.6 years for group A and 13.4 ± 1.7 years for group B. For group B, the mean DAP was 47.0 µGy m 2 with an E of 0.13 mSv. For group A, the mean DAP was 85.3 µGy m 2 with an E of 0.24 mSv. This represents a dose reduction of 45%. Mean image quality scores for group A (27.9 ± 2.4) and group B (28.1 ± 2.3) were similar (p = 0.612). Interobserver agreement was observed to be excellent (ICC 0.92). Conclusion This study demonstrates that a low-dose full-spine radiograph can be performed in patients with idiopathic scoliosis without loss of image quality.Graphical abstract These slides can be retrieved under Electronic Supplementary Material. Key points1. RadiaƟon safety is an important aspect, in parƟcular when imaging children.2. Phantom studies can help to understand the impact of technical radiography parameters on image quality and dose.3. RadiaƟon dose could be dramaƟcally decreased (45%) to 0.13 mSv.
The current retrospective study investigates the natural evolution of head-shaft angle (HSA) and neck-shaft angle (NSA) in childhood. It is not known if a high HSA in early childhood leads to a high HSA in adulthood. This study aims to characterize the evolution of HSA and compares it with the more commonly known NSA in healthy children. We measured radiographs of 84 different healthy hips of children between 3 and 14.5 years old who underwent at least 2 radiographs of the pelvis, corresponding to 286 measurements. We used a linear mixed model to determine the covariance between random intercept and slope while allowing each individual hip to change over time. The covariance for HSA between random intercept and random slope was -4.262 (p < 0.001), corresponding to a high negative correlation of -0.717, for NSA -2.754 (p = 0.031) or a high negative correlation of -0.779. HSA and NSA were strongly correlated, a value of 0.736 (p < 0.001) was measured. The high negative correlation for random intercept and random slope means that the higher the initial value (intercept), the steeper the decline (slope). Therefore HSA decreases faster in hips with high HSA at an early age. Hips with high HSA in early childhood do not necessarily lead to hips with high HSA in adulthood. Our results may aid in future clinical decision making in patients with developmental dysplasia of the hip (DDH) with high HSA in particular.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.