IOA 2022

Foot Surgery using Magnesium Resorbing Screws

Tomer Gazit Muhammed Eisa Kefah Khawalde Dror Robinson Eyal Heller Mustafa Yassin
The Department of Orthopedics,, Hasharon Hospital, Rabin Medical Center Affiliated to Tel Aviv University School of Medicine, Israel

Introduction:
Magnesium is a relatively new metal used in orthopedic surgery. The advantage of these screws is the ability to release magnesium ions, enabling better mitochondrial function and possibly faster callus formation. Another advantage is the self-absorption of the implants. However the disadvantages are the inflammatory process likely to be associated with implant absorption and the loss of mechanical integrity within a short period of time.

The following investigation compared results of hallux valgus surgery using a minimally invasive technique comparing standard titanium screws to magnesium screws.

Methods:
The magnesium screws used were 3.2 cannulated screws by Magnzix, the titanium screws used were 4 mm in diameter. 26 cases of Magnezix and 34 cases of titanium screws were compared. The assessment included interfoot difference in 5th metatarsal base circumference (IF5C), AOFAS hallux valgus score, intermetatarsal angle (IMA), hallux valgus angle (HVA), visual analogue scale (VAS) and PGIC (patient centered asessement)

Results:
There were no technical complications during surgery in either group. The pre-op HVA (45±8) was similar in both groups, as was IMA (12±4). At one year the HVA was similar in both groups (18±5) as was the IMA 8±3). Healing of osteotomies was apparent at one month in the HVA group and by 3 months in the titanium group.

The IF5C was increased in the Magnezix group at 4 weeks post surgery by 8±2 millimeters (p<0.05), the difference at 6 weeks, 3 months and 6 months as well as 1 year was not significant. AOFAS score at 6 months was similar. PGIC at 6 months was similar in both groups. VAS at one month averaged 1±1 in the magnesium group versus 5±2 (p<0.01)

Conclusion:
Using magnesium screws is safe in hallux valgus surgery. The radiological results are comparable at one year follow-up as are the foot validated scores and the PGIC. There was less pain one month after surgery in the magnesium group perhaps due to slightly faster healing of the osteotomies. It is possible to conclude that using the magnesium screws is not inferior to the traditional titanium screws. The loss of mechanical integrity does not seem to jeopardize the results.