German Clinical Trials Register

Acronym/abbreviation of the study

SCAMAG

URL of the study

No Entry

Brief summary in lay language

The scaphoid bone is the second largest of the eight carpal bones. It is located in the second row closest to the thumb. Scaphoid fractures account for approximately 5% of all carpal fractures. Primarily males are affected with an age between 20 and 29 years. Scaphoid fractures often need to be treated by surgery, where a screw is inserted into the bone for fixation and subsequent healing. Commonly, titanium screws are used for fixation, which remain in the body or are removed after healing. An alternative is MAGNEZIX CS, a magnesium-based screw which degradates over time in hte body. Aim of this tria is to show that MAGNEZIX CS screws are not inferior to titanium screws with respect to mobility of the hand and possible complications during healing. Concurrently, the aim is to show in a smaller group of patients undergoing MRI that MAGNEZIX CS screws are superior to titanium screws because of their degradation property. This is to be demonstrated by fewer disturbances, i.e., artifacts in the MRIs.

Brief summary in scientific language

Scaphoid fractures are the most common carpal fractures. Surgeons may choose between different implant materials, including conventional metal implants, such as titanium, or absorbable implants, such as magnesium-based material. Magnesium-based implants have beneficial material properties, such as higher stability than polymer implants, osteoconductivity, inhibition of infections and almost no artifacts in MRI scans. The aim of this trial is demonstrate non-inferiority of MAGNEZIX CS screws compared to classical titanium Herbert screws for scaphoid fractures of types A2, B1, B2 and B3. The trial is a multicentre, blinded observer, randomized controlled parallel group post market trial with two groups. Approximately 190 patients with scaphoid fractures will be randomized in a 1:1 ratio with stratification by centre either to MAGNEZIX CS or titanium screws. Each patient will be followed up for 1 year. Inclusion criteria include normal wrist function prior to fraction, no previous surgery of the wrist, no complex regional pain syndrome, no simultaneous fractures on both arms and no ligamentary concomitant injuries. Surgical procedures and aftercare will be performed according to the S3 AWMF guideline for scaphoid fractures. There are three primary endpoints: 1. patient related wrist evaluation (PRWE) total score 6 months after randomization, 2. safety event, i.e., evidence of bone union until 6 months, no adverse device effect during surgery, no adverse device effect during wound healing, no reoperation within 1 year, no serious adverse device effect within 1 year, and 3. artifacts in magnet resonance imaging (MRI) as measured by difference between maximum length of an artifact between 1-year follow-up and baseline. Non-inferiority of MAGNEZIX CS compared to titanium screws will be investigated for primary endpoints 1 and 2 using the full analysis set based on the intention to treat population (FAS) and the per protocol population at the one-sided 2.5% test level. Superiority of MAGNEZIX CS over titanium screws will be established using the FAS population at the two-sided 5% test level only if non-inferiority has been established for primary endpoints 1 and 2. The t-test-based confidence interval based will be used for analyzing endpoint 1, Wilson's score interval for endpoint 2 and the Welch test for endpoint 3. The ethics commission's statement of the MHH for amendment 3 (age >= 16, recruitung time extended) is available since 09.10.2019 at the number 7614.