Considerations for Metacarpal Fixation

Plate Location*
ConsiderationsIndex Finger (Second) MetacarpalMiddle Finger (Third) Metacarpal
ApproachConsider soft-tissue injury2 incisions3 incisions, transposition of EPL
ReductionLigamentotaxis indirect reduction possible for some but not all fractures13Indirect vs. open reductionIndirect vs. open reduction. Additional standard incision over 4th extensor compartment may facilitate reduction of lunate facet or volar lip9,18
BiomechanicsBiomechanical stability must support loading during fracture-healingSuperior biomechanical stability to extension and flexion forces compared with external fixation16No studies specifically addressing biomechanics of plating to the 3rd metacarpal
TendonWrist joint immobilization limits motion of wrist extensor tendons but not digital extensor excursionNo tendinous entrapment in cadaveric studies33. Average length of ECRB tendon contact to plate, 6 cm34. Average ECRL tendon contact to plate, 6.5 cm34. Average index EDC and EIP contact, 0.8 cm. No middle EDC contactEPL and either APL or APB consistently entrapped in cadaveric model33. No ECRL or ECRB contact34. Average length of index finger EDC and EIP contact to plate, 5.1 cm34. Average middle finger EDC contact, 10.4 cm34. EIP and EPL tendon entrapment possible with 2-incision technique34
NerveIatrogenic nerve injury can result in poor outcomesBranches of the RSN at risk34No branches of RSN observed crossing over the middle finger metacarpal in cadaveric studies33,34. PIN lies below footprint of plate34
RetinaculumExtensor retinaculum irritation and rupture is of concernNo entrapment or injury noted in cadaveric models33,34Risk of splitting or entrapping extensor retinaculum33
  • * EPL = extensor pollicis longus, ECRB = extensor carpi radialis brevis, ECRL = extensor carpi radialis longus, EDC = extensor digitorum communis, EIP = extensor indicis proprius, APL = abductor pollicis longus, APB = abductor pollicis brevis, RSN = radial sensory nerve, PIN = posterior interosseous nerve.

  • Cadaveric model did not incorporate 3-incision technique as is used clinically.