Intramedullary fixation of metacarpal and phalangeal bone fractures with bioabsorbable Mg K-wire in 20 cases

The treatment of irreducible or severely displaced metacarpal and phalangeal bone fractures is still much debated. The recent development of the bioabsorbable magnesium K-wire is thought to allow effective treatment upon insertion via intramedullary fixation by minimizing articular cartilage injuries without discomfort until pin removal and drawbacks, such as pin track infection and metal plate removal. Therefore, this study investigated and reported the effects of intramedullary fixation with the bioabsorbable magnesium K-wire in unstable metacarpal and phalangeal bone fractures.

This study included 19 patients admitted to our clinic for metacarpal or phalangeal bone fractures from May 2019 to July 2021. As a result, 20 cases were examined among these 19 patients.

Bone union was observed in all 20 cases, with a mean bone union time of 10.5 (SD 3.4) weeks. Reduction loss was observed in six cases, all showing dorsal angulation with a mean angle of 6.6° (SD 3.5°) at 4.6 weeks as compared with that noted in the unaffected side. The gas cavity upon H₂ gas formation was first observed approximately 2 weeks postoperatively. The mean DASH score was 33.5 for instrumental activity and 9.5 for work/task performance. No patient complained of notable discomfort after surgery.

Intramedullary fixation with the bioabsorbable magnesium K-wire may be used for unstable metacarpal and phalanx bone fractures. This wire is expected to be a particularly favorable indication for shaft fractures, although care should be taken due to the possibility of complications related to rigidity and deformity.