Objectives. This biomechanical study was conducted to compare fixation stability of the proximal fragments and their mechanical characteristics in proximal femur models of unstable basicervical IT fractures fixed by cephalomedullary nailing using 3 different types of the femoral head fixation.Methods. A total of 36 composite femurs corresponding to osteoporotic human bone were used. These specimens were fixed with Gamma 3 (hip screw type; group 1) in 12, Gamma 3 U-blade (screw-blade hybrid type; group 2) in 12, and proximal femoral nail antirotation-II (helical blade type; group 3) in 12, respectively, and an unstable basicervical IT fracture was created by an engraving machine. After preloading and cyclic loading, the migration of the proximal fragment according to 3 axes was assessed by the stereophotogrammetric method and the migration of screw or blade tip within the femoral head was measured radiographically. Next, the vertical load was continued at a speed of 10 mm/min until the construct failure occurred. Finite element analysis was additionally performed to measure the stress and compressive strain just above the tip of screw or blade within the femoral head.Results. The rotational change of the proximal fragment according to the axis of screw or blade was much greater in group 1 than in groups 2 and 3 (p=0.016 and p=0.007, respectively). Varus collapse was greater in group 3 than in group 2 (p=0.045). Cranial and axial migration of screw or blade within the femoral head were significantly greater in group 3 than in both group 1 (p=0.001 and p=0.002, respectively) and group 2 (p=0.002 and p=0.016, respectively). On finite element analysis, group 3 showed the highest peak von-Mises stress value (13.3 MPa) and compressive strain (3.2%) just above the tip of the blade within the femoral head. Meanwhile, groups 1 and 2 showed similar results on two values.Conclusions. Screw-blade hybrid type and blade type would be more effective in minimizing rotation instability of the proximal fragment in unstable basicervical IT fractures. However, varus collapse of the proximal fragment and cranial and axial migration within the femoral head were greater with blade type than screw-blade hybrid type.
1 November 2017 in Clinical Interventions in Aging
Purpose: Postoperative delirium is a risk factor for worse outcome after hip fracture surgery in elderly patients. Postoperative delirium is associated with anesthesia, postoperative pain, and patient factors. We investigated the incidence, predictors, and prognostic implications of postoperative delirium after hemiarthroplasty (HA) in elderly patients with femoral neck fracture. Patients and methods: A total of 356 consecutive patients aged >70 years who underwent HA for femoral neck fracture were enrolled. Diagnosis of delirium was made by a psychiatrist based on patient status and an objective scoring system. The patients were divided into 2 categories according to the HA onset time (immediate [≤24 h after surgery] vs delayed delirium [>24 h after surgery]) and its incidence, predictors and mortality were evaluated. Results: Postoperative delirium was diagnosed in 110 patients (30.9%) during hospitalization. Immediate and delayed delirium occurred in 59 (53.6%), and 51 (46.4%) patients, respectively. The independent predictors of immediate delirium included age (odds ratio [OR] 1.47, 95% CI 0.98–2.23, p=0.066), and general anesthesia (OR 2.25, 95% CI 1.17–4.43, p=0.015). The independent predictors of delayed delirium were parkinsonism (OR 5.75, 95% CI 1.66–19.96, p=0.006), intensive care unit stay (OR 1.85, 95% CI 0.97–3.56, p=0.064), and higher American Society of Anesthesiologists grade (OR 2.33, 95% CI 0.90–6.07, p=0.083). On Kaplan–Meier survival analysis, the 2-year survival rate was significantly lower in the immediate delirium group than those in the delayed and control groups (71.0% vs 83.6% vs 87.8%, respectively; p=0.031). Conclusion: Immediate and delayed delirium after HA for femoral neck fracture had different predictors and immediate delirium was associated with worse prognosis.
Elderly patients undergoing hip fracture surgery (HFS) are at increased risk of postoperative venous thromboembolism (VTE). To reduce this risk, combined postoperative mechanical and chemical thromboprophylaxis has been routinely performed after HFS in these patients. This retrospective case-control study was conducted to evaluate the additional effectiveness of preoperative mechanical thromboprophylaxis for the prevention of VTE following HFS in elderly patients. Of 539 consecutive patients aged 70 years or older undergoing HFS, 404 (control group) did not receive preoperative mechanical thromboprophylaxis, while 135 (study group) received mechanical thromboprophylaxis using an intermittent pneumatic compression device and graduated compression stockings from the time of admission until surgery. All patients received combined postoperative mechanical and chemical thromboprophylaxis following HFS in accordance with the same protocol. The incidence of symptomatic VTE confirmed based on clinical symptoms and 3-dimensional CT angiography within one month of surgery was investigated in both groups. The American Society of Anesthesiologists grade was higher (p = 0.016) in the study group and more patients in this group had concomitant cardiovascular and neurologic diseases (p = 0.005 and p = 0.009, respectively). In addition, more patients in the study group had received anticoagulant medication preinjury owing to comorbidities (39% vs 28%, p = 0.025). The overall incidences of symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) were 7.4% and 3.7%, and 2.2% and 1.5% in the control and study groups, respectively. According to multiple logistic regression, symptomatic DVT significantly reduced in the study group (OR 0.28, p = 0.042), while there was no significant difference in the incidence of symptomatic PE between the two groups (p = 0.223). Preoperative mechanical thromboprophylaxis may confer an additional benefit by preventing postoperative VTE without adding more risk of perioperative bleeding in elderly patients with hip fracture.