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

Table 1 Indications, contraindications, and key selection criteria for intramedullary headless screw vs Kirschner wire vs plate fixation in metacarpal and proximal phalanx fractures

Criterion	IMHS	K-wire	Plating
Extra-articular transverse/oblique	Preferred	Acceptable	Acceptable
Metacarpal neck	Preferred	Acceptable	Less ideal
Comminuted diaphyseal	Acceptable	Poor control	Preferred
Intra-articular	Contraindicated	Limited role	Preferred
Osteoporotic bone	Caution	Acceptable	Preferred
Open fracture Gustilo I	Acceptable	Acceptable	Acceptable
Open fracture Gustilo II/III	Contraindicated	Caution	Preferred
Pediatric (open physes)	Contraindicated	Preferred	Rarely
Need for early motion	Best	Poor	Good
Resource-limited setting	Costly	Best	Moderate cost
Learning curve	Moderate	Low	Moderate-high

IMHS: Intramedullary headless screw; K-wire: Kirschner wire.

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.

Table 3 Comparative outcomes of intramedullary headless screw vs Kirschner wire vs plate fixation for metacarpal fractures (based on meta-analyses)

Outcome measure	IMHS	K-wire	Plating	Evidence level
DASH score (mean)	0.6	7.4	9.8	Meta-analysis[7,14]
Grip strength recovery	Superior	Moderate	Comparable to IMHS	Meta-analysis[7,24]
Reoperation rate	4%	11%	11%	Meta-analysis[7]
Infection rate	< 3%	5%-15% (pin tract)	< 3%	Systematic review[14]
Union rate	> 97%	95%-98%	> 97%	Systematic review[14]
Operative time	Short	Shortest	Longest	Cohort studies[19,21]
Early mobilization	Yes (no splint)	No (splint required)	Yes	Cohort studies[43,45]
Implant removal	Rarely required	Usually required	Sometimes required	Systematic review[38,39]
Implant cost	Moderate-high	Low	Moderate-high	Cost analysis[20]

DASH: Disabilities of the arm, shoulder and hand; IMHS: Intramedullary headless screw; K-wire: Kirschner wire.