A 3D-printed migration assay for analysis of chemotactic response in the presence of spatially-distributed sources of chemoattractants is presented. The assay enables multiplexed studies with on-plate controls. The assay was applied to the analysis of glioma cell chemotactic response in the presence of competing gradients of bradykinin (BK) and epidermal growth factor (EGF). The device has broad applications ranging from analysis of competitive chemotactic responses associated with diseases and development of 3D printed constructs.
Objectives:
To evaluate the rate of reoperation in patients without sagittal plane malalignment who underwent percutaneous screw fixation of a valgus-impacted femoral neck fracture.
Design:
Retrospective case series.
Setting:
Two Level 1 academic trauma centers.
Patients and Intervention:
Two hundred seven patients >50 years of age with valgus-impacted femoral neck fractures treated with at least 3 large-diameter (>6.5 mm) cancellous screws from 2013 to 2019. Patients were excluded if there was a sagittal plane fracture deformity.
Main Outcome Measurements:
The primary outcome was reoperation. Secondary outcomes considered “major complications” included: avascular necrosis, varus collapse or implant cutout, nonunion, deep infection, and hematoma requiring reoperation. Surgical fixation strategies (screw configuration, aim) and implant type (partial vs. fully threaded cancellous screws) were secondarily compared.
Results:
Average patient age was 77 years, and median clinical follow-up was 658 days. Thirty-one patients (15%) required reoperation, and the major complication rate was 17.3% (36 complications in 33 patients). Logistic regression analysis demonstrated a higher risk of reoperation with constructs consisting of all partially threaded screws (17.0%) compared with the use of at least 1 fully threaded screw (7.5%) when an inverted triangle configuration was used (odds ratio, 2.50; 95% CI, 0.81–7.77).
Conclusions:
This study demonstrated a relatively high rate of reoperation and major complications in patients with valgus-impacted femoral neck fractures without sagittal malalignment treated with in situ percutaneous screw fixation.
Level of Evidence:
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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