Comparison of SCAphoid fracture osteosynthesis by MAGnesium-based headless Herbert screws with titanium Herbert screws: protocol for the randomized controlled SCAMAG clinical trial

Abstract

Background Scaphoid fractures are the most common carpal fractures. They often need to be treated by surgery, where the use of a compression screw is the globally accepted gold standard. Surgeons may choose between different implant materials including titanium alloys, which remain in the body or are removed after healing. An alternative are biodegradable magnesium-based implants. Properties of magnesium alloys include high stability, osteoconductivity, potential reduction of infections and few artifacts in magnetic resonance imaging (MRI). The aim of this trial is to demonstrate non-inferiority of magnesium-based compression screws compared with titanium Herbert screws for scaphoid fractures. Methods The trial is designed as a multicenter, blinded observer, randomized controlled parallel two-group post market trial. Approximately 190 patients will be randomized (1:1) with stratification by center either to titanium or magnesium-based compression screws. Follow-up is 1 year per patient. Surgical procedures and aftercare will be performed according to the German treatment guideline for scaphoid fractures. The first primary endpoint is the patient-rated wrist evaluation (PRWE) score after 6 months. The second primary endpoint is a composite safety endpoint including bone union until 6 months, no adverse device effect (ADE) during surgery or wound healing and no serious ADE or reoperation within 1 year. The third primary endpoint is the difference in change MRI artifacts over time. Non-inferiority will be investigated for primary endpoints 1 (t-test confidence interval) and 2 (Wilson’s score interval) using both the full analysis set (FAS) and the per protocol population at the one-sided 2.5% test-level. Superiority of magnesium over titanium screws will be established using the FAS at the two-sided 5% test-level (Welch test) only if non-inferiority has been established for both primary endpoints. Secondary endpoints include quality of life. Discussion This study will inform care providers whether biodegradable magnesium-based implants are non-inferior to standard titanium Herbert screws for the treatment of scaphoid fractures in terms of wrist function and safety. Furthermore, superiority of magnesium-based implants may be demonstrated using MRI, which is used as surrogate endpoint for screw degradation. Trial registration DRKS, DRKS00013368 . Registered Dec 04, 2017. Electronic supplementary material The online version of this article (10.1186/s12891-019-2723-9) contains supplementary material, which is available to authorized users.

Research status of biodegradable metals designed for oral and maxillofacial applications: A review

“…Mg-based BMs with excellent mechanical strength and good biocompatibility are considered promising candidates for biodegradable bone fixation screws and plates. Mg-based alloys screws are the only BM bone fixation device that have achieved clinical translation [ 23 , 72 ]. The elastic modulus of Mg-based alloys is very close to those of natural bone, especially natural cortical bone, which greatly weakens the “stress shielding” effect, thus, decreasing bone resorption [ 19 , 73 ].…”

A Modular Approach to Combine Postmarket Clinical Follow-Up Studies and Postmarket Surveillance Studies

“…Starting point for template development were CIPs developed by the authors. [20][21][22]29 One of the published protocols was used as prototype for developing the CIP template. The authors next expanded the CIP template to a full protocol.…”

“…A.Z. is board-certified trial statistician 19 and has extensively worked on medical devices, including planning [20][21][22] and analysis of randomized controlled trials, 23 methodological work on medical devices, and its regulatory affairs 24,25 and publication recommendations. 26,27 K.K.…”

“…is involved in the quality management of trials for approximately 20 years. Her work includes a doctoral thesis and publications on standard operating procedures (SOPs) for clinical trials, 28 the publication of study protocols, [20][21][22] and methodological work on medical device trials. 25…”

Translational status of biomedical Mg devices in China

“…1 shows some representative Mg-based implants cross the world.

Fig. 1Some representative Mg-based implants [[11], [12], [13], [14], [15], [16], [17], [18]].

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