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Complications of surgical treatment for osteoporotic fractures
Published in Peter V. Giannoudis, Thomas A. Einhorn, Surgical and Medical Treatment of Osteoporosis, 2020
Paul C. Baldwin, Christian Krettek
These findings have been supported in subsequent studies evaluating the outcomes of fixed-angle locking plate fixation in osteoporotic proximal humerus fractures. Micic et al. analyzed early failure (less than 4 weeks) of fixed-angle locking plate constructs in eight osteoporotic patients and found that varus collapse and screw cut-out was the cause of failure (14). In all eight patients, medial calcar support was absent. In three of the eight patients, initial malreduction of the fracture was observed. In a second study, Oswley et al. retrospectively reviewed 53 patients treated with fixed-angle locking plates for displaced proximal humerus fractures. Of these 53 patients, 36% developed postoperative complications including screw cut-out (23%), varus displacement (25%), and AVN (4%). Revision surgery was performed in 13% of the 53 patients. When secondary analysis was performed, the observed complications disproportionately occurred in patients older than 60 years of age and with osteoporosis (57%) (15).
McMurray's osteotomy: A forgotten procedure of the hip
Published in K. Mohan Iyer, Hip Preservation Techniques, 2019
In the long term, McMurray's osteotomy patients may develop secondary osteoarthritis due to the altered biomechanics of the hip and may require total hip replacement. These cases are not straightforward and are often quite complicated to execute (Figures 19.4 and 19.5). There are several technical challenges posed by the previous osteotomy while executing a total hip replacement.6 These include: Soft tissue contractures: Various muscles around the hips are severely contracted and must be adequately released during the surgery. These muscles include iliopsoas, adductors, glutei, and short external rotators.Bony abnormalities: There is a severe distortion of the anatomy of the proximal femur with blockage of the medullary canal by the bone formed at the previously done osteotomy site. There may also be a deficiency of medial bone stock if the calcar was previously involved wholly or partially in the osteotomy.Surgical problems: It may be quite difficult to restore the hip center and fully correct the limb-length discrepancy in these cases.
Direct Anterior Approach to the Hip Joint
Published in K. Mohan Iyer, Hip Joint in Adults: Advances and Developments, 2018
The proximal femur should now be easily accessible (Fig. 17.10) to allow standard broaching and insertion of the femoral component. We use a Charnley curette to first pass along the calcar and enter the femoral canal. The curved, blunt end minimises any risk of femoral perforation. Standard femoral broaching is then undertaken.
Finite element analysis of necessity of reduction and selection of internal fixation for valgus-impacted femoral neck fracture
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Yahui Dai, Ming Ni, Bang Dou, Zhiyuan Wang, Yushan Zhang, Xueliang Cui, Wenqian Ma, Tao Qin, Xiaobin Xu, Jiong Mei
Cannulated screws and SHS are the most commonly used implants for fixation of femoral neck fractures, and we compared biomechanical characteristics of them for valgus-impacted femoral neck fractures. Our results showed that von Mises stress was concentrated at the medial and inferior sides in the intact femur, the same as the calcar femorale located. The calcar femorale acts an important role in the transmission of forces from femoral neck to the shaft. Zhang et al. stated that the calcar femorale redistributes stress in the proximal femur by decreasing the load in the posterior and medial aspects and increasing the load in the anterior and lateral aspects (Zhang et al. 2009). All 4 surgical methods increased the stress at the medial and inferior sides of the femoral neck in the rank order of Model 7 < Model 6 < Model 5 < Model 4. The stress in Model 7 (15.921 MPa) and displacements in Models 2 and 7 (0.332 and 0.329 mm, respectively) were closest to the values for the intact femur (Model 1: stress, 11.911 MPa; displacement, 0.38 mm). The latter result indicates that the valgus-impacted fracture was stable in Models 2 and 7, and explains why some patients can move the hip joint and feel no pain. Fixing the fracture by cannulated screws after reduction (Model 5) significantly increased the displacement (0.45 mm), making it the most unstable treatment option.
Computational prediction of the long-term behavior of the femoral density after THR using the Silent Hip stem
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Zainab Al-Hajaj, Pouria Tavakkoli Avval, Habiba Bougherara
The periprosthetic bone loss in the calcar zone 5 was predicated to be −14% using the Silent Hip prosthesis. Patel et al. (2013) found that zone 1 showed bone resorption of −19% after 5 years follow-up using the uncemented short stem. On the other hand, Tavakkoli Avval et al. (2014) studied the bone remodeling of a traditional long stem prosthesis using the same thermodynamic model, the results revealed that the bone loss in the calcar region was predicted to be −46.25%. Additionally, Niinimaki and Jalovaara (1995) reported that the maximum bone loss in calcar region was observed to be −40%. Zone 1 and zone 5 contain a higher percentage of trabecular bone compared to other regions, which have predominantly cortical bone. Previous studies reported that the bone density reduction for zone 1 ranges from −14.4% to −29.9%, and for zone 5 it ranges from −15.2% to −34.6% (Arabmotlagh et al. 2006; Boden and Skoldenberg 2006; Dan et al. 2006; Sköldenberg et al. 2006; Hananouchi et al. 2007), which is in line with the current results.
A simple and effective 1D-element discrete-based method for computational bone remodeling
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Diego Quexada-Rodríguez, Kalenia Márquez-Flórez, Miguel Cerrolaza, Carlos Duque-Daza, Olfa Trabelsi, M.A Velasco, Salah Ramtani, Marie Christine Ho-Ba-Tho, Diego Garzón-Alvarado
In the first medical case, a zone with less density called Ward’s triangle (in honor to Ward, who first described the internal structure of the proximal femur in 1938) can be seen between the ogival system of the trochanteric plateau and the cervicocephalic support system. This is an important region because cervicotrochanteric fractures originate here in people of advanced age (Martín and Kochen 2011). The calcar, which extends from the posteromedial cortex in the femoral neck to the distal part of the lesser trochanter, is identified with a high bone density in the final topologies. This is an important fact since this region helps to support stems from implants, which need a dense cancellous bone for a proper anchorage; for this reason, numerous fixation methods have been proposed on this zone, see (Cha et al. 2019 and Peng et al. 2020).