Bioabsorbable magnesium screw versus conventional titanium screw fixation for medial malleolar fractures

Abstract

Background It is still unknown whether bioabsorbable magnesium (Mg) screws provide an advantage over titanium screws in the treatment of medial malleolar (MM) fractures. The purpose of this retrospective study is to compare the clinical and radiological outcomes of MM fractures fixed with either bioabsorbable Mg screws or conventional titanium screws. Materials and methods A cohort of 48 patients with MM fractures who underwent compression screw fixation was retrospectively reviewed. Twenty-three patients (16 male, 7 female; mean age: 37.9 ± 17.7 years) were treated with bioabsorbable Mg screws, and 25 patients (14 male, 11 female; mean age: 45.0 ± 15.7 years) were treated with conventional titanium screw fixation. All patients were followed up for at least 1 year, with a mean time of 24.6 ± 10.5 months (12–53 months). The American Orthopedic Foot and Ankle Society (AOFAS) scale was used to evaluate the clinical results. The Kellgren–Lawrence (KL) osteoarthritis grading was used to evaluate posttraumatic osteoarthritis on final ankle radiographs. Fracture union, rate of implant removal, and complications were recorded. Comparative analysis of two independent groups was performed using the chi-squared test and the Mann–Whitney U-test. Results The two groups were comparable concerning demographic and clinical characteristics. Age (p = 0.146), sex (p = 0.252), side (p = 0.190), MM fracture type (p = 0.500), associated fractures (p = 0.470), and follow-up period (p = 0.903) were similar between the groups. At final follow-up examination, AOFAS score (p = 0.191) was similar between groups. Fracture union was achieved in all cases. Grade of posttraumatic osteoarthritis, according to KL, was equally distributed in both groups (p = 0.074). No deep infection or osteomyelitis was seen. Five patients in the titanium screw group underwent implant removal, due to pain in three of them and difficulty in wearing shoes in the other two (p = 0.031). Implant removal was performed after a mean of 14.2 ± 3.1 months (12–19 months). Conclusions Bioabsorbable Mg and titanium screws had similar therapeutic efficacy in MM fracture fixation regarding functional and radiological outcomes. However, the rate of implant removal was higher with titanium screws. Bioabsorbable Mg screws may be a favorable fixation option since secondary implant removal procedures can be prevented. Level of evidence Level IV, Retrospective case series.

Bioresorbable Magnesium-Based Alloys as Novel Biomaterials in Oral Bone Regeneration: General Review and Clinical Perspectives

“…These zones are localized around the screws and slightly increase during the first 6 months after implantation. However, radiolucent zones decreased afterwards and were not related to complications [ 85 , 87 , 90 , 93 , 101 , 105 , 107 ]. Physicians and surgeons have to be aware of this radiographical aspect of product accumulation around the implanted Mg-based material as well as the rare possibility of subcutaneous gas accumulation.…”

Can Hardware Removal be Avoided Using Bioresorbable Mg-Zn-Ca Screws After Medial Malleolar Fracture Fixation? Mid-Term Results of a First-In-Human Study

“…According to a recent systematic review and meta-analysis including eight clinical trials and reviewing a total number of 230 patients, the estimated complication rate for Mg-based implants was 13.3% [29] . In the current literature a total of five clinical studies including prospective and retrospective clinical trials investigating Mg-based alloys implanted in foot ankles are registered and exhibit similar clinical and functional outcomes [30][31][32][33][34] . All of these studies aimed on the clinical implementation of Mg implants alloyed with REEs.…”

In Vivo Imaging of Biodegradable Implants and Related Tissue Biomarkers

“…Notable examples for this approach is the use of calciu aluminium and various rare metals to adjust the degradation properties of ma implants [4,11] and hydroxyapatite composites that include collagen, poly( (PLLA), polydiolcitrates, polyvinyl alcohol or other polymers [12][13][14]. Figure 4 an example of clinical application of a specially designed compression scre MgYREZr alloy (magnesium with yttrium, rare earth metal, and zirconium) and treatment to possess an oxide film and to combine both material and production to optimize their performance [15]. Mechanically, implants differ according to production methods, geometry face treatment.…”

“…( a , d ) are radiographs; ( b , c , e , f ) are taken using CT. White arrows point at gas formation around implant. Reproduced from May et al (2020) [ 15 ]. Copyright Springer Nature, 2020.…”