You are in: eMedicine Specialties > Sports Medicine > Wrist and Hand Mallet FractureArticle Last Updated: Jun 17, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 9
  Author: Michael E Robinson, MD, Consulting Staff, Department of Orthopedics, Division of Primary Care Sports Medicine, Permanente Medical Group and Kaiser Hospital Michael E Robinson is a member of the following medical societies: American Academy of Family Physicians, American Medical Society for Sports Medicine, and Wilderness Medical Society Editors: Anthony J Saglimbeni, MD, Staff Physician, Family Practice Residency, Medical Director, Center for Sports Medicine, O'Connor Hospital; Private Practice; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Henry T Goitz, MD, Chief, Sports Medicine, Associate Professor, Department of Orthopaedic Surgery, Medical College of Ohio; Jon B Whitehurst, MD, Clinical Instructor of Surgery, University of Illinois College of Medicine; Partner and Executive Board Member, Rockford Orthopedic Associates; Orthopedic Chairman, Rockford Memorial Hospital; Craig C Young, MD, Professor, Departments of Orthopedic Surgery and Community and Family Medicine, Medical Director of Sports Medicine, Sports Medicine Fellowship Director, Medical College of Wisconsin Author and Editor Disclosure Synonyms and related keywords: baseball finger, drop finger, hammer finger, swan-neck deformity, mallet finger, mallet deformity, phalangeal fractures INTRODUCTIONSection 2 of 9
  BackgroundThe term mallet finger has long been used to describe the deformity produced by disruption of the terminal extensor mechanism at the distal interphalangeal (DIP) joint.1, 2, 3 Mallet finger is the most common closed tendon injury that is seen in athletes; this injury is also common in nonathletes after "innocent" trauma. Mallet finger has also been referred to as drop, hammer, or baseball finger (although baseball accounts for only a small percentage of such injuries). Athletes and coaches often believe mallet injuries to be minor, and many cases go untreated. All individuals with finger injuries, including suspected mallet finger, should have a systematic evaluation performed. Good results can usually be obtained with early treatment of such injuries, whereas delay or lack of treatment may produce permanent disability. Functional AnatomyThe tendinous mallet injury represents a disruption of the terminal extensor tendon at its insertion on the distal phalanx. Mallet injury is most commonly caused by forced flexion against an actively extended digit (eg, when a ball strikes the end of a finger); a direct blow over the dorsum of the DIP joint may also produce a mallet finger. The resultant deformity occurs by unopposed flexion of the distal phalanx. Mallet deformity can also be associated with a fracture of the dorsal articular surface of the distal phalanx. Radiographically, these bony avulsions can be characterized into 3 common patterns, as follows:
Generally, fleck fractures and nondisplaced avulsions that involve up to 40% of the joint surface are believed to be stable injuries.2 Individuals with stable injuries are candidates for conservative treatment. CLINICALSection 3 of 9
HistoryTypically, the athlete with a mallet fracture has a history of a direct blow to the finger, followed by pain and swelling at the DIP joint and by the inability to actively fully extend the DIP joint. PhysicalThe physical examination findings of mallet finger include the following (see Images 1-5):
DIFFERENTIALSSection 4 of 9
Jammed Finger Phalangeal Fractures Swan-Neck Deformity WORKUPSection 5 of 9
Imaging Studies
TREATMENTSection 6 of 9
Acute PhaseRehabilitation ProgramPhysical TherapyTreatment of the tendinous mallet finger or stable mallet fracture (see Image 5) consists of splinting the DIP joint in full extension for 6 weeks1, 3, 4, 5; the PIP joint is allowed full motion. After 6 weeks, active range of motion (ROM) may be initiated. To ensure maximum tendon stability, most authors recommend an additional 2 weeks of night splinting and up to 8 weeks of splinting during athletic activities that may place the finger at risk of reinjury. Splinting can be accomplished with the use of an aluminum foam splint (see Image 3) that is placed either on the dorsal or volar surface of the finger and taped to hold the DIP joint in extension. Molded plastic splints (see Image 4) that have been designed specifically for the treatment of mallet injuries are commercially available. Most athletes with mallet finger are able to participate in their sport during treatment. Additional padding and support of the affected finger may be appropriate for play in contact sports. Throwing athletes who injure their dominant hand may initially miss practice and playing time. Instructing the patient in proper splint care and compliance is essential. Splints may be changed to allow for skin cleansing and drying, but the DIP joint must remain continuously in extension. Any flexion event may adversely affect the outcome. Medical Issues/ComplicationsCaution should be used when positioning the involved DIP joint during splinting. Excessive hyperextension or excessive dorsal pressure over the joint may compromise circulation and lead to skin necrosis. Surgical InterventionThe appropriate indications for surgical fixation of mallet fractures, which techniques to use, and the accuracy of outcome measures are frequently debated.1, 4, 6, 7 Most authors agree that mallet fractures that are associated with volar subluxation of the distal phalange should be referred to an orthopedic surgeon for fixation. Referral should also be considered for cases in which there are large or displaced avulsion fragments that involve more than 30-40% of the joint surface.6 Surgical fixation of a mallet fracture of the thumb is sometimes recommended due to the greater extrinsic displacing forces across the IP joint. MISCELLANEOUSSection 7 of 9
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REFERENCESSection 9 of 9
Article Last Updated: Jun 17, 2008 | ||||||||||||||||||||||||||||||||||||||||||
