Intra- medullary nail fixation as a treatment method for impending fracture non-union of a near-total trans-metacarpal amputation initially treated with K-wire fixation – A case report

In hand and digital replantation, Kirschner wires (K-wires) osteosynthesis is regularly used for bone fixation. Percutaneous K-wire fixation (PKWF) has several disadvantages, such as restriction of range of motion (ROM)—as it often crosses the soft tissues of the joints—, need for early extraction before bone-union prolonging immobilization, potentially increasing pin tract infection, and the fact that it does not offer the strongest type of fixation construct compared to other methods.

All these factors limit early ROM rehabilitation protocols, therefore impacting functional outcomes. We present a case report of a near-total trans metacarpal (MCP) hand crush amputation by a hydraulic press injury that initially underwent PKWF. The K- wires were extracted at seven weeks post-operatively. The concern of impending non-union and the need for prolonged immobilization after K-wire extraction was addressed by intra-medullary nail fixation (IMNF).

In this case, we decided to utilize a less conventional method of osteo-synthesis IMNF to address the concern of impending non-union after initial fixation with K-wires in TMCHR. It provided a stronger fixation construct, no splint immobilization time, and early ROM rehabilitation protocol. All these factors facilitate bone union and improve functional outcomes.

This should stimulate further research for this type of situation between IMNF and other types of osteosynthesis by studying the incidence of non-union, infection rates, functional results, and other outcomes. This could also stimulate fabrication, in the laboratory, of intra-medullary nails for metacarpals with antibiotic impregnated hydroxyapatite/poly-L-lactide (HPLLA)—which are not only bioabsorbable, but also osteoconductive—for osteosynthesis in crushed amputations or comminuted fractures. There are several reports in the literature for digital replantation, but none found for amputations at the MCP level.