Fracture Metacarpal

Most metacarpal shaft fractures are spiral, indicating a torsional injury (Rajesh et al. 2001). As in the phalanges, careful assessment is required of rotational deformity, although this is probably more easily performed clinically than radiologically. Treatment is similar to phalangeal injuries. If stabilisation of the metacarpal is required to maintain reduction, K-wires which pass from the fractured metacarpal across to the adjacent, intact metacarpal can be inserted. 

Daniell, H., Osteoporosis and the slender smoker vertebral compression fractures and loss of metacarpal cortex in relation to postmenopausal cigarette smoking and lack of obesity, Archives of Internal Medicine, 136, 298, 1976. 

Fig. 7.25. Accessory ossification centres at the bases of the index and little finger metacarpals (arrows) that can simulate fractures...

The Metacarpals 289 Metacarpal Epiphysis and Physis 289 Metacarpal Ne Fractures 290 Metacarpal Shaft Fractures 290 Fractures of the Base of the Metacarpal 290 Metacarpophalangeal Dislocations 291 Carpometacarpal Dislocations 291... 

The Thumb 291 Paediatric Skier s Thumb 292 Dislocation of the Thumb MCP Joint 292 Fractures of the Thumb Metacarpal Base 293... 

Relative to the phalanges the metacarpals are reasonably protected, although several series of hand fractures found the fifth metacarpal to be the most frequently injured bone (Rajesh et al. 2001 Vadivelu et al. 2006). Incidence peaks in older schoolchildren, when the mechanism of injury is usually punching, or involvement in contact sports. 

Fractures involving the epiphysis and physis of the finger metacarpals are uncommon (Mahabir et al. 2001). Epiphyseal fractures are rare, and non displaced fractures may heal well (Fig. 19.19). Displaced split fractures of the epiphysis may need open reduction to restore articular congruity (Graham and Waters 2001). Intra-articular fractures of the epiphysis are important to identify as they are associated with joint effusions. If these effusions are under enough pressure, blood flow to the epiphysis maybe sufficiently compromised to cause avascular necrosis. Preventative joint aspiration may be considered (McElfresh and Dobyns 1983). 

Of the finger metacarpal fractures involving the physis, 85% are Salter-Harris type II, with a simi-... 

Fig. 19.19. Healing fractures of the index finger metacarpal head and neck...

Fig. 19.21. A 7-year-old boy punched his brother, sustaining a transverse buckle fracture of the index metacarpal neck...

Fig. 19.20. Salter-Harris II fracture of the little finger metacarpal...

Injuries at this site are not common. The little finger sustains more metacarpal base fractures than the other... 

These are rare injuries. If associated with fractures of the metacarpal base, the dislocations are analogous to Bennett s fractures of the thumb (Sandzen 1973). Post-reduction these injuries tend to redislocate, and often require stabilisation (Graham and Waters 2001). 

Fractures of the head and shaft of the thumb metacarpal are similar to those seen in the other digits in terms of treatment. Fractures of the base of the metacarpal, however, deserve special attention due to their potential impact on thumb function (Graham and Waters 2001). Four categories are described. Type A fractures are extra-articular fractures of the shaft, usually in the proximal third of the metacarpal with a transverse or oblique orientation (Fig. 19.28). There is often apex lateral angulation, with medial impaction. Good remodelling can be expected due to the proximity to the physis. 

TypeD fractures are intra-articular Salter-Harris 111 or IV injuries of the proximal thumb metacarpal, resembling the adult Bennett s fracture (Fig. 19.32). These injuries are fortunately not common, as they can be very difficult to treat. Open reduction and internal fixation are often required... 

Fig. 19.28. Type A fracture ofthe thumb metacarpal proximal third...

Fig. 19.29. Type B fracture of the thumb metacarpal base with a medial metaphyseal spur...

Fig. 19.31. Type C fracture of the thumb metacarpal base, lateral view reveals marked displacement...

Fig. 19.32. Small Salter-Harris 111 fracture at the base of the thumb metacarpal, type D fracture...

Cornwall R (2006) Finger metacarpal fractures and dislocations in children. Hand Clin 22 1-10 Cornwall R, Ricchetti ET (2006) Pediatric phalanx fractures unique challenges and pitfalls. Clin Orthop Relat Res 445 146-156... 

Letts M, Rowhani N (1993) Galeazzi-equivalent injuries of the wrist in children. J Pediatr Orthop 13 561-566 Light TR, Ogden JA (1987) Metacarpal epiphyseal fractures. J Hand Surg [Am] 12 460-464... 

McElfresh EC, Dobyns JH (1983) Intra-articular metacarpal head fractures. J Hand Surg [Am] 8 383-393 Mizuta T, Benson WM, Foster BK, Paterson DC, Morris LL (1987) Statistical analysis of the incidence of physeal injuries. J Pediatr Orthop 7 518-523... 

Salter RB, Harris WR (1963) Injuries involving the epiphyseal plate. J Bone Joint Surg Am 45-A 587-622 Sandzen SC (1973) Fracture of the fifth metacarpal resembling Bennett s fracture. Hand 5 49-51 Seymour N (1966) Juxta-epiphysial fracture of the terminal phalanx of the finger. J Bone Joint Surg Br 48 347-349 Vadivelu R, Dias JJ, Burke ED, Stanton J (2006) Hand injuries in children a prospective study. J Pediatr Orthop 26 29-35... 

Fig. 21.17. Leukaemia. Pathological fracture developing through leukaemic deposit in the first metacarpal. The differential diagnosis would include dactylitis due to other causes. (Case courtesy of Dr. K Johnson)...

Fig.l0.81a-d. Occult trapezium fracture. Coronal a gray-scale and b power Doppler 12-5 MHz US images obtained over the lateral aspect of the distal wrist with corresponding c reformatted 2D CT coronal image and d 3D CT image reveal the lateral dislocation of the distal fracture fragment (arrow) of the trapezium (asterisk) with secondary displacement of the adjacent radial artery (arrowheads). M, first metacarpal... 

Fig. 11.58a-e. Posterior fracture dislocation of the fourth metacarpal bone in a young patient who hit a wall with his fist, a Longitudinal and b transverse 12-5 MHz US images obtained over the base of the fourth metacarpal bone (4 Met) reveal its posterior displacement associated with an avulsion fracture of the dorsal hamate (arrows). 5 Met, fifth metacarpal. Corresponding c,d two-dimensional and e three-dimensional reconstructed CT images confirmed the US diagnosis. Previous standard radiographs were considered normal... 

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