Metacarpal fractures

Classification

Usually descriptive

• Transverse
• Oblique (short/long)
• Spiral
• Displacement/ angulation/ shortening

What is acceptable angulation/ displacement?

• Any rotational deformity is poorly tolerated and should be corrected.
• shortening > 4 mm should be corrected as it affects intrinsic muscle function. (Shortening is often resisted if splinted by intact adjacent metacarpals if the transverse intermetacarpal ligament is intact)
• Palmar angulation- the, long flexors and interossei, can accomodate 10 degrees of angulation. The 5th metacarpal is more mobile than the second and can accomodate more angulation. Similarly a higher level of angulation can be accommodated at the neck level than fractures of the shaft.

There is no absolute degree of angulation once again it is important to look at function and expectation. As a guide:

• Shaft fractures- 10 to15 degrees of dorsal angulation may be accepted for the second and third metacarpals, 20 degrees for the 4th and 30 degrees for the 5th metacarpal shaft
•  Subcapital (neck) fractures - As much as 50° of dorsal angulation in the fourth metacarpal and 70° in the fifth metacarpal have healed without pain or subjective functional deficit, although with varying degrees of cosmetic deformity.

 Rockwood and Green suggests:

Treatment

If the fracture is minimally displaced symptomatic treatment alone is required with return of motion and early function. For mild displacement some form of external protection and early mobilisation is required. If the fracture is at shaft level a short forearm cast will suffice. For stable fractures of the neck the protection should extend to the PIP level with dorsal control of the MP joints in full flexion. (for 3-4 weeks)

If the fracture is displaced and reduction is required then some form of fixation is often required to maintain the position.

Methods of fixation

• Closed reduction and transverse percutaneous k -wire fixation into adjacent intact metacarpal (4 weeks)
• Closed  reduction and intramedullary fixation (k-wire or steinman pin)
• Open reduction and internal fixation with interfragmentary screws and/ or plate (metallic or bioabsorbable)

Freeland, Alan E. MD. Geissler, William B. MD. Weiss, Arnold-Peter C. MD. Operative Treatment of Common Displaced and Unstable Fractures of the Hand. Journal of Bone & Joint Surgery - American Volume. 83-A(6):927-945, June 2001.
 

Waris, Eero. Ashammakhi, Nureddin. Happonen, Harri. Raatikainen, Timo. Kaarela, Outi. Tormala, Pertti. Santavirta, Seppo. Konttinen, Yrjo T. Bioabsorbable Miniplating Versus Metallic Fixation for Metacarpal Fractures. Clinical Orthopaedics & Related Research. 1(410):310-319, May 2003.

Mockford, Brian J. F.R.C.S.. Thompson, Neil S. F.R.C.S.. Nolan, Paul C. F.R.C.S.. Calderwood, James W. F.R.C.S.. Antegrade Intramedullary Fixation of Displaced Metacarpal Fractures: A New Technique. Plastic & Reconstructive Surgery. 111(1):351-354, January 2003.

Klein, David M.; Belsole, Robert J.; Percutaneous Treatment of Carpal, Metacarpal, and Phalangeal Injuries. Clinical Orthopaedics & Related Research. (375):116-125, June 2000.

Drenth, D. J.. Klasen, H. J.. External fixation for phalangeal and metacarpal fractures. Journal of Bone & Joint Surgery - British Volume. 80-B(2):227-230, March 1998

Gonzalez, Mark H.; Hall, Robert F.; Intramedullary Fixation of Metacarpal and Proximal Phalangeal Fractures of the Hand. Clinical Orthopaedics & Related Research. (327):47-54, June 1996.

Last updated 11/09/2015