Magnesium Bioabsorbable vs Titanium Screws in Hallux Valgus Surgery: A Prospective, Randomized Medium-term Trial

Metal implants, the gold standard for osteotomy fixation in foot surgery, do have inherent problems. A relatively high percentage of patients undergoing hallux valgus correction require secondary surgery for metal implant removal. Although available since the 1980s, bioabsorbable implant use in foot surgery has been limited because of concerns of osteolysis and inferior strength. Magnesium screws are bioabsorbable implants without the inherent risks associated with other bioabsorbable implants. We prospectively compared outcomes of MAGNESIX to metal implants in hallux valgus deformity correction.

A prospective, randomized study comparing radiographic and clinical outcomes between hallux valgus corrections fixated with magnesium (24 feet) or titanium (25 feet) screws, with an average follow-up of 44 and 35 months, respectively. Clinical outcomes were assessed using the American Orthopaedic Foot & Ankle Society (AOFAS) forefoot score and radiographic parameters measured on weightbearing radiographs pre-operatively and at final follow-up. All complications were documented.

Both magnesium and titanium cohorts showed statistically significant improvements in radiographic parameters (P < .05) and AOFAS scores (P < .05), with no statistically significant difference between cohorts.All post-operative radiographs in the magnesium cohort had visible gas formation at 6 weeks, resolving by 12 weeks, and all screws fully resorbed on final radiographs with no evidence of osteolysis (more than 1 year). Four recurrences occurred in the magnesium cohort vs 3 in the titanium cohort. A single case of hallux varus was noted in the magnesium group and 1 incidence of screw removal for symptomatic hardware in the titanium group.

We found no difference between bioabsorbable magnesium screws and titanium screws for fixation in hallux valgus surgery, although small between-group differences may not have been detectable given the relatively small sample size. Magnesium screws appeared safe with no allergic reactions or wound complications and may offer added benefits of not interfering with advanced imaging, decreasing the need for hardware removal and likely easier revision surgery.

Level II, randomized controlled trial.