Biomechanical analysis of two medial buttress plate fixation methods to treat Pauwels type III femoral neck fractures

Background Femoral neck fractures in young people are usually Pauwels Type III fractures. The common treatment method are multiple parallel cannulated screws or dynamic hip screw sliding compression fixation. Due to the huge shear stress, the rate of complications such as femoral head necrosis and nonunion is still high after treatment. The aim of our study was to compare the stabilities of two fixation methods in fixating pauwels type III femoral neck fractures. Methods All biomimetic fracture samples are fixed with three cannulated screws combined with a medial buttress plate. There were two fixation groups for the buttress plate and proximal fracture fragment: Group A, long screw (40 mm); Group B, short screw (6 mm). Samples were subjected to electrical strain measurement under a load of 500 N, axial stiffness was measured, and then the samples were axially loaded until failure. More than 5 mm of displacement or synthetic bone fracture was considered as construct failure. Results There were no significant differences in failure load (P = 0.669), stiffness (P = 0.842), or strain distribution (P > 0.05) between the two groups. Conclusions Unicortical short screws can provide the same stability as long screws for Pauwels Type III Femoral Neck Fractures.

Bone Mineral Density Changes in Long-Term Kidney Transplant Recipients: A Real-Life Cohort Study of Native Vitamin D Supplementation

Vitamin D insufficiency has been associated with reduced bone mineral density (BMD) in kidney transplant patients (KTRs). However, the efficacy of vitamin D supplementation on BMD remains poorly defined, especially for long-term KTRs. We aimed to investigate the effect of native vitamin D supplementation on the BMD of KTRs during a 2-year follow-up. Demographic, clinical, and laboratory data were collected. BMD was evaluated with standard DEXA that was performed at baseline (before vitamin D supplementation) and at the end of study period. BMD was assessed at lumbar vertebral bodies (LV) and right femoral neck (FN) by a single operator. According to WHO criteria, results were expressed as the T-score (standard deviation (SD) relative to young healthy adults) and Z-score (SD relative to age-matched controls). Osteoporosis and osteopenia were defined as a T-score ≤ −2.5 SD and a T-score < −1 and a > −2.5 SD, respectively. Based on plasma levels, 25-OH-vitamin D (25-OH-D) was supplemented as recommended for the general population. Data from 100 KTRs were analyzed. The mean study period was 27.7 ± 3.4 months. At study inception, 25-OH-D insufficiency and deficiency were recorded in 65 and 35 patients. At the basal DEXA, the percentage of osteopenia and osteoporosis was 43.3% and 18.6% at LV and 54.1% and 12.2% at FN, respectively. At the end of the study, no differences in the Z-score and T-score gains were observed. During linear mixed model analysis, native vitamin D supplementation was found to have a negative nitration with Z-score changes at the right femoral neck in KTRs (p < 0.05). The mean dose of administered cholecalciferol was 13.396 ± 7.537 UI per week; increased 25-OH-D levels were found (p < 0.0001). Either low BMD or 25-OH-vitamin D concentration was observed in long-term KTRs. Prolonged supplementation with 25-OH-D did not modify BMD, Z-score, or T-score.

Short-Term Clinical Efficacy of Femoral Neck System Versus Multiple Cannulated Compression Screws in the Treatment of Garden III and IV Femoral Neck Fractures

Femoral neck system (FNS) , as a novel minimally invasive internal fixation device, has been gradually applied in the treatment of femoral neck fracture.However, there are few related clinical studies on FNS at present, especially there is no clinical report on FNS in treating GardenIII and IV femoral neck fractures. The aim of the present study was to compare the short-term clinical efficacy of FNS and multiple cannulated compression screws (MCCS) in the treatment of Garden III and IV femoral neck fractures. The data of 78 patients with femoral neck fracture who were admitted to three teaching hospitals affiliated to Anhui Medical University and received internal fixation with FNS and MCCS from June 2019 to December 2020 were collected for a retrospective study. There were 39 patients in both the FNS and MCCS groups. The basic data, perioperative data were recorded and compared between the two groups of patients. The results of the study are encouraging. The operation time was shorter in FNS group than that in MCCS group (p<0.001). The post-operative partial and complete weight-bearing time was earlier in FNS group than that in MCCS group (p<0.001). The Harris hip score in FNS group was higher than that in MCCS group (p<0.001). The incidence rate of lateral thigh irritation in FNS group and MCCS group was 0 (0/39) and 33.3% (13/39), respectively (χ2=15.600, p<0.001). The length of femoral neck shortening was significantly shorter in FNS group than that in MCCS group (t=-5.093, p<0.001). In conclusion, The application of FNS for Garden III and IV femoral neck fractures can shorten the operation time, reduce the frequency of intraoperative fluoroscopy, and facilitate the recovery of hip joint function, so it provides a novel choice for the treatment of Garden III and IV femoral neck fractures in young people.

All that clots is not blood: Bone cement implantation syndrome presenting as an intracardiac mass and pulmonary embolism

Bone cement implantation syndrome (BCIS) is a rare and potentially fatal perioperative complication of cemented orthopaedics surgery. A CT-pulmonary angiogram and echocardiogram images were acquired from an 88-year-old patient who had a perioperative collapse while undergoing a revision operation for a peri-implant fracture of the right femoral neck. Findings were suggestive of an intracardiac clot connected to a saddle pulmonary artery embolus. Patient also developed disseminated intravascular coagulation. Overall findings were suggestive of bone cement implantation syndrome.