Clinical considerations in intramedullary headless screw fixation of metacarpal and proximal phalanx fractures

Table 2 Technique selection guide for intramedullary headless screw fixation by bone and fracture pattern

Bone	Fracture pattern	Preferred technique	Key risk
Metacarpal	Transverse shaft, subcapital, short oblique	Technique 1 retrograde single-screw	Articular cartilage at metacarpal head (4%-5% surface)
Metacarpal	Comminuted subcapital/distal shaft	Technique 2 Y-strutting double-screw	Screw conflict; must use unequal lengths
Proximal phalanx	Extra-articular shaft/neck	Technique 3 antegrade intra-articular (preferred)	Inadequate subluxation if MCP at 90°
Proximal phalanx	Subluxation inadequate	Technique 4 antegrade trans-articular	Dual articular violation (metacarpal head + phalanx base)
Proximal phalanx	Alternative retrograde access	Technique 5 PIP retrograde	Central slip injury; larger PIP chondral defect
Proximal phalanx	Comminuted proximal third	Technique 6 dual antegrade Y-strutting	Screw conflict; 2.2 mm screws mandatory

MCP: Metacarpophalangeal joint; PIP: Proximal interphalangeal joint.