Publications by authors named "Alexander Telis"

2 Publications

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Treatment of tibial plateau fractures with a novel fenestrated screw system for delivery of bone graft substitute.

Eur J Orthop Surg Traumatol 2021 Jan 24. Epub 2021 Jan 24.

Department of Orthopaedic Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.

Purpose: The purpose of this study was to describe the incidence of subsidence in patients with AO/OTA 41 (tibial plateau) fractures which were repaired with a novel fenestrated screw system to used to deliver CaPO4 bone substitute material to fill the subchondral void and support the articular reduction.

Methods: Patients with unicondylar and bicondylar tibial plateau fractures were treated according to the usual technique of two surgeons. After fixation, the Zimmer Biomet N-Force Fixation System®, a fenestrated screw that allows for the injection of bone substitute was placed and used for injection of the proprietary calcium phosphate bone graft substitute into the subchondral void. For all included patients, demographic information, operative data, radiographs, and clinic notes were reviewed. Patients were considered to have articular subsidence if one or more of two observations were made when comparing post-operative to their most recent clinic radiographs: > 2 mm change in the distance between the screw and the lowest point of the tibial plateau, > 2 mm change in the distance between the screw and the most superior aspect of the plate. Data were analyzed to determine if there were any identifiable risk factors for complication, reoperation, or subsidence using logistic regression. Statistical significance was set at p < 0.05.

Results: 34 patients were included with an average follow-up of 32.03 ± 22.52 weeks. There were no overall differences between height relative to the medial plateau or the plate. Two patients (5.9%) had articular subsidence. Six patients (15.2%) underwent reoperation, two (6%) for manipulations under anaesthesia due to arthrofibrosis, and four (12%) due to infections. There were 6 (19%) total infections as 2 were superficial and required solely antibiotics. One patient had early failure.

Conclusion: Use of a novel fenestrated screw system for the delivery of CaPO4 BSM results in articular subsidence and complication rates similar to previously published values and appears to be a viable option for addressing subchondral defects in tibial plateau fractures.

Level Of Evidence: IV.
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http://dx.doi.org/10.1007/s00590-021-02871-yDOI Listing
January 2021

Standard Versus Low-Dose Computed Tomography for Assessment of Acetabular Fracture Reduction.

J Orthop Trauma 2020 09;34(9):462-468

Department of Orthopaedic Surgery, University of Southern California, Keck School of Medicine, Los Angeles, CA.

Objective: First, to assess the impact of varying computed tomography (CT) radiation dose on surgeon assessment of postfixation acetabular fracture reduction and malpositioned implants. Second, to quantify the accuracy of CT assessments compared with the experimentally set displacement in cadaver specimens. We hypothesized that a CT dose would not affect the assessments and that CT assessments would show a high concordance with known displacement.

Methods: We created posterior wall acetabular fractures in 8 fresh-frozen cadaver hips and reduced them with varying combinations of step and gap displacement. The insertion of an intra-articular screw was randomized. Each specimen had a CT with standard (120 kV), intermediate (100 kV), and low-dose (80 kV) protocols, with and without metal artifact reduction postprocessing. Reviewers quantified gap and step displacement, overall reduction, quality of the scan, and identified intra-articular implants.

Results: There were no significant differences between the CT dose protocols for assessment of gap, step, overall displacement, or the presence of intra-articular screws. Reviewers correctly categorized displacement as anatomic (0-1 mm), imperfect (2-3 mm), or poor (>3 mm) in 27.5%-57.5% of specimens. When the anatomic and imperfect categories were condensed into a single category, these scores improved to 52.5%-82.5%. Intra-articular screws were correctly identified in 56.3% of cases. Interobserver reliability was poor or moderate for all items. Reviewers rated the quality of most scans as "sufficient" (60.0%-72.5%); reviewers more frequently rated the low-dose CT as "inferior" (30.0%) and the standard dose CT as "excellent" (25%).

Conclusion: A CT dose did not affect assessment of displacement, intra-articular screw penetration, or subjective rating of scan quality in the setting of a fixed posterior wall fracture.
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http://dx.doi.org/10.1097/BOT.0000000000001778DOI Listing
September 2020
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