eMedicine Specialties > Orthopedic Surgery > Hand & Upper Extremity

Bennett Fracture

Author: Steven V Priano, MD, Assistant Professor of Orthopedic Surgery, Department of Orthopedics and Sports Medicine, Ohio State University College of Medicine and Public Health
Coauthor(s): Mark E Baratz, MD, Professor, Department of Orthopaedics, Drexel University College of Medicine; Residency Director, Department of Orthopaedics, Allegheny General Hospital; Consulting Staff, Allegheny Orthopaedic Associates
Contributor Information and Disclosures

Updated: Jan 11, 2008

Introduction

In 1882, Edward Hallaran Bennett, MD, described the fracture of the base of the first metacarpal that bears his name. Bennett described the anatomic details of the fracture and suggested that early diagnosis and treatment are imperative to prevent loss of function of this highly mobile joint.1,2,3,4,5

Problem

Unless properly recognized and treated, this intra-articular fracture subluxation may result in an unstable arthritic joint with secondary loss of motion and pain. Because the thumb carpometacarpal (CMC) joint is critical for pinch and opposition, this injury may severely affect function.

Frequency

The thumb is a highly mobile border digit. For that reason, injury to this ray is common.

Etiology

Axial loading of a partially flexed thumb metacarpal causes this injury.

Pathophysiology

Thumb CMC joint stability is maintained by 5 ligaments and the articular contours. The most critical of these stabilizers is the volar oblique ligament. This ligament courses from the volar lip of the trapezium to the volar ulnar corner of the thumb metacarpal base. The injury occurs when an axial force is transmitted through a partially flexed thumb metacarpal. The portion of the metacarpal onto which the volar oblique ligament inserts remains in anatomic position, and the remainder of the articular base subluxates in a dorsal, radial, and proximal direction because of the pull of the abductor pollicis longus (APL).

Presentation

Patients present with swelling and pain at the thumb base. On examination, motion is limited and CMC instability is frequently noted with gentle stress of the thumb metacarpal.

Indications

Closed reduction and thumb spica cast immobilization can be effective in the treatment of some Bennett fractures. Generally, cases characterized by small avulsion fractures and minimal articular incongruity and instability can be managed in this fashion. These patients must be carefully monitored with serial radiography. The strong pull of the abductor pollicis longus (APL) frequently leads to displacement. As a result, open or closed reduction combined with internal fixation is frequently required. More than 1 mm of articular incongruity after closed reduction is an indication for operative intervention. This degree of articular incongruity is associated with an increased rate of articular degeneration in the thumb CMC joint over time.2,3,5,6

Relevant Anatomy

The thumb affords prehensile abilities that were essential in human evolution. The bony anatomy of the thumb consists of 2 phalanges and a metacarpal, which articulates with the trapezium bone in the distal carpal row. The metacarpal is actually a primordial phalanx.

The CMC joint consists of an articulation between the trapezium and the metacarpal base composed of 2 reciprocally interlocking saddles with perpendicular longitudinal axes. Ligamentous stability at the trapeziometacarpal joint is maintained by the anterior (volar) and posterior oblique ligaments, the anterior and posterior intermetacarpal ligaments, and the dorsal radial ligament. The anterior (volar) oblique ligament originates on the trapezium and inserts into the volar ulnar beak of the thumb metacarpal. This is the most important ligament in maintaining CMC stability. The dorsal ligament is not as strong as the volar ligament but is reinforced by the APL.

Contraindications

Contraindications to closed treatment include an open fracture, an unstable fracture, unsuccessful closed reduction with residual articular incongruity greater than 1 mm, or instability and joint subluxation.

More on Bennett Fracture

Overview: Bennett Fracture
Workup: Bennett Fracture
Treatment: Bennett Fracture
Follow-up: Bennett Fracture
Multimedia: Bennett Fracture
References
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References

  1. Bennett EH. Fractures of the Metacarpal Bones. Dublin Med Sci J. 1882;73:72-75.

  2. Green DP, Stern PJ. Fractures of the metacarpals and phalanges. In: Green's Operative Hand Surgery. New York, NY. Churchill Livingstone;1999:711-772.

  3. Peimer CA, Wolfe SW, Elliot AJ. Metacarpal and carpometacarpal trauma. In: Surgery of the Hand and Upper Extremity. 1st ed. New York, NY. McGraw-Hill;1996:883-920.

  4. Rockwood CA, Green DP, Butler TE Jr. Fractures and dislocations of the hand. In: Rockwood and Green's Fractures in Adults. Philadelphia, Pa. Lippincott-Raven;1996:607-744.

  5. Soyer AD. Fractures of the base of the first metacarpal: current treatment options. J Am Acad Orthop Surg. Nov-Dec 1999;7(6):403-12. [Medline].

  6. Nagaoka M, Nagao S, Matsuzaki H. Trapeziometacarpal joint instability after Bennett's fracture-dislocation. J Orthop Sci. Jul 2005;10(4):374-7. [Medline].

  7. Sawaizumi T, Nanno M, Nanbu A, Ito H. Percutaneous leverage pinning in the treatment of Bennett's fracture. J Orthop Sci. 2005;10(1):27-31. [Medline].

  8. Lutz M, Sailer R, Zimmermann R, Gabl M, Ulmer H, Pechlaner S. Closed reduction transarticular Kirschner wire fixation versus open reduction internal fixation in the treatment of Bennett's fracture dislocation. J Hand Surg [Br]. Apr 2003;28(2):142-7. [Medline].

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Further Reading

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Keywords

thumb CMC fractures, thumb carpal-metacarpal fracture, thumb carpometacarpal fracture, Bennett's fracture, Bennett's fractures, thumb injury, thumb fracture

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Contributor Information and Disclosures

Author

Steven V Priano, MD, Assistant Professor of Orthopedic Surgery, Department of Orthopedics and Sports Medicine, Ohio State University College of Medicine and Public Health
Steven V Priano, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons
Disclosure: Nothing to disclose.

Coauthor(s)

Mark E Baratz, MD, Professor, Department of Orthopaedics, Drexel University College of Medicine; Residency Director, Department of Orthopaedics, Allegheny General Hospital; Consulting Staff, Allegheny Orthopaedic Associates
Mark E Baratz, MD is a member of the following medical societies: Allegheny County Medical Society, American Academy of Orthopaedic Surgeons, American Association for Hand Surgery, American Orthopaedic Association, American Society for Surgery of the Hand, Orthopaedic Research Society, and Pennsylvania Orthopaedic Society
Disclosure: Nothing to disclose.

Medical Editor

Michael S Clarke, MD, Clinical Associate Professor, Department of Orthopedic Surgery, University of Missouri-Columbia School of Medicine
Michael S Clarke, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Academy of Pediatrics, American Association for Hand Surgery, American College of Surgeons, American Medical Association, Arthroscopy Association of North America, Clinical Orthopaedic Society, Mid-Central States Orthopaedic Society, and Missouri State Medical Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Thomas R Hunt III, MD, John D Sherrill Professor and Director of Orthopaedic Surgery, Surgeon in Chief of UAB Highlands Hospital, Director of Hand and Upper Extremity Fellowship, University of Alabama at Birmingham
Thomas R Hunt III, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association for Hand Surgery, American Orthopaedic Association, American Orthopaedic Society for Sports Medicine, American Society for Surgery of the Hand, AO Foundation, Mid-America Orthopaedic Association, and Southern Orthopaedic Association
Disclosure: Tornier Consulting fee Review panel membership; Tornier Royalty None; Tornier Ownership interest None

CME Editor

Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital
Dinesh Patel, MD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association of Physicians of Indian Origin, American College of International Physicians, and American College of Surgeons
Disclosure: Nothing to disclose.

Chief Editor

Harris Gellman, MD, Consulting Surgeon, Broward Hand Center; Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine
Harris Gellman, MD is a member of the following medical societies: American Academy of Medical Acupuncture, American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Society for Surgery of the Hand, and Arkansas Medical Society
Disclosure: Nothing to disclose.

 
 
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