Early results using a biodegradable magnesium screw for modified chevron osteotomies

Abstract

This is the first larger study analyzing the use of magnesium-based screws for fixation of modified Chevron osteotomies in hallux valgus surgery. Forty-four patients (45 feet) were included in this prospective study. A modified Chevron osteotomy was performed on every patient and a magnesium screw used for fixation. The mean clinical follow up was 21.4 weeks. The mean age of the patients was 45.5 years. Forty patients could be provided with the implant, in four patients the surgeon decided to change to a standard metallic implant. The AOFAS, FAAM and pain NRS-scale improved markedly. The hallux valgus angle, intermetatarsal angle and sesamoid position improved significantly. Seven patients showed dorsal subluxation, rotation or medial shifting of the metatarsal heads within the first 3 months. One of these patients was revised, in all others the findings were considered clinically not significant or the patients refused revision. This study shows the feasibility of using magnesium screws in hallux valgus-surgery. Surgeons starting with the use of these implants should be aware of the proper handling of these implants and should know about corrosion effects during healing and its radiographic appearance. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2207-2214, 2016.

Magnesium-Based Absorbable Metal Screws for Intra-Articular Fracture Fixation

“…Reports currently focus on elective foot surgery such as Chevron-type osteotomies of the first metatarsal bone [2, 13]. Our report now expands the application into the field of trauma surgery.…”

“…Comparing the results to a control group fixed with titanium alloy screws, no disadvantages were identified [2]. Early results (1-year experience) have recently been published, reporting good clinical outcome after distal metatarsal osteotomies for hallux valgus in the short term and a high patient satisfaction [13]. Up to now, there are no clinical reports whatsoever on trauma applications.…”

A detailed microstructural and corrosion analysis of an additively manufactured magnesium alloy produced by selective laser melting

“…1) is notable [35,51]. There have been few investigations on the use of such Mg-based implants in chevron osteotomies for hallux valgus corrective surgery [52], reporting significant functional outcomes, which were maintained for a period of at least 3 to 6 months postoperative. The authors of cited clinical studies utilising the newly manufactured Mg implants have however noted "signs of early corrosion with subsequent (bone) disintegration" [52].…”

“…There have been few investigations on the use of such Mg-based implants in chevron osteotomies for hallux valgus corrective surgery [52], reporting significant functional outcomes, which were maintained for a period of at least 3 to 6 months postoperative. The authors of cited clinical studies utilising the newly manufactured Mg implants have however noted "signs of early corrosion with subsequent (bone) disintegration" [52]. The recent studies have thus specified a need for further considerations on "corrosion effects during healing and radiographic appearance" and "a fastrelease of hydrogen gas", which is considered to be non-toxic but could cause local tissue and bone displacement via subcutaneous gas cavities [52,53].…”

“…The authors of cited clinical studies utilising the newly manufactured Mg implants have however noted "signs of early corrosion with subsequent (bone) disintegration" [52]. The recent studies have thus specified a need for further considerations on "corrosion effects during healing and radiographic appearance" and "a fastrelease of hydrogen gas", which is considered to be non-toxic but could cause local tissue and bone displacement via subcutaneous gas cavities [52,53]. Thus, understanding of the corrosion process is of great importance in future implementation of the SLMed Mg-based alloys, certainly not only in the biomedical but also structural applications.…”