UNIVERSAL DEVICE FOR ORTHOPEDIC SCREW EXPLANTATION: A descriptive and comparative analysis of its applicability, effectiveness, and reproducibility across different systems and metal alloys

• Grant number: 25/09726-1
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2025
• End date: February 28, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Luis Gustavo Gosuen Gonçalves Dias
• Grantee: Luis Gustavo Gosuen Gonçalves Dias
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated researchers: Alefe Luiz Caliani Carrera ; Bruno Watanabe Minto ; Renato Barroco Neto

Abstract

Orthopedic demand in small animal practice increases the need for proper management of surgical implants. The removal of orthopedic implants, especially locked plates and screws, is common, though often hindered by the wide range of implant designs and frequent screw head stripping due to complications during application. Therefore, this study aims to evaluate and compare the applicability, effectiveness, and reproducibility of a universal device for explantation of stripped orthopedic screws across different metal alloy scenarios.To this end, a universal explantation kit made of stainless steel will be tested by three different orthopedic surgeons on screw systems of 1.5, 2.0, 2.7, and 3.5 mm, from three different manufacturers, produced in two distinct materials: stainless steel and titanium. Two groups of test specimens will be created-one made of stainless steel and one of titanium. Each group will consist of a straight locked plate with 10 holes and 10 screws (12 mm in length) locked to the plate, all of which will have their drive recesses mechanically stripped, rendering standard screwdriver engagement unfeasible.Each group will include two subgroups: a control subgroup (screws removed using the original screwdriver from the system) and a test subgroup (screws removed using the universal device). Each subgroup will include implants from three different suppliers. The analysis will be conducted by the three evaluators, who will attempt to remove 10 screws per system and material group. Parameters assessed will include the quality of fit between the explantation device and the screw, the feasibility of screw removal, the time required to initiate unscrewing, and the time to complete screw removal.The resulting numerical data will undergo statistical analysis to assess the repeatability of the device's performance, as well as correlations between variables across groups and implant systems. The study is expected to validate and confirm the applicability, effectiveness, and repeatability of the universal explantation device for removing orthopedic screws that do not permit screwdriver engagement, and to establish its efficacy across different implant manufacturers. (AU)