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Fig. 1 Anteroposterior radiographs of a spiral metacarpal shaft fracture. This spiral oblique fracture has several fragments (A) and was fixated with multiple interfragmentary lag screws (B) in order to provide secure fixation that could withstand early rehabilitation. Reproduced from Henry MH: Fractures of the proximal phalanx and metacarpals in the hand: Preferred methods of stabilization. 2008;16(10):586-595.

AAOS Now

Published 7/1/2017
|
Peter Pollack

Metacarpal Shaft Fractures a Challenge in Athletes

Patient needs should dictate treatment approach
During a presentation at the American Society for Surgery of the Hand Specialty Day meeting, Julie E. Adams, MD, offered advice on the treatment of metacarpal shaft fractures in athletic patients and on return to play issues. Dr. Adams stated that there are multiple options for treatment, but the optimal approach is often driven by patient needs.

"The stakes are very different for the weekend warrior and professional athletes," she noted.

Approaches and indications
Treatment options for metacarpal shaft fractures include the following:

  • splinting
  • closed reduction and pinning (longitudinal or transverse)
  • intramedullary pin
  • open reduction, lag screw, or plate fixation
  • absorbable fixation
  • external fixation

Dr. Adams' indications for fixation are as follows:

  • irreducible or unstable fractures
  • open fractures
  • multiple metacarpal fractures
  • malrotation
  • excessive angulation
  • patient needs (athletes, surgeons, etc)

Dr. Adams proffered several tips on dealing with metacarpal shaft fractures. She noted that rotational deformity can play a key role in treatment decisions. Many shaft fractures are spiral oblique fractures, when lag screw fixation may be appropriate (Fig 1). For this approach, the fracture length should be at least twice the bony diameter, and the screw diameter can vary. She noted that this approach offers a stable, low-profile fixation. However, the treatment is not appropriate for all fracture types.

Regarding transverse fractures, she stated that shortening and angulation at the neck are generally well tolerated, particularly in the ulnar digits.

"For metacarpal neck fractures, one can accept almost unlimited angulation in the small finger," she explained, "but an equal amount of angulation at the shaft has a more profound effect. I use the 10-degree and 20-degree rule in the shaft—10 degrees of angulation accepted at the index and long digits; 20 degrees at the ring and the small digits."


J Am Acad Orthop Surg

Shortening
Published literature suggests that 3 mm to 5 mm of shortening may be an indication of shaft fracture, said Dr. Adams.

"In their study, Strauch et al, found that 2 mm of shortening is associated with 7 degrees of extensor lag," she explained. "In most hands, the extrinsic extensors can compensate for that, but not always. The reality is that this is individualized according to the patient and his or her tolerance for surgery, immobilization, and other changes."

Dr. Adams cited as an example a patient with a fracture due to basketball. The patient had a torsional injury, shortening of the ring finger, and rotational deformity.

"In this patient you might consider plate fixation," she said. "The advantage is earlier motion, but the potential disadvantage is that he or she may have hardware irritation and eventual need for hardware removal."

According to Dr. Adams, absorbable plates are a technology that may not be ready for "prime time."

"There are some published case series and case studies on absorbable plates, and the findings are mixed," she noted. "On the surface it appears to be a good idea. If they work correctly, they should limit soft tissue adhesions and the need for hardware removal. The devices are designed to resorb in 2 to 4 years. However, there are reports of reactions that require extensive débridement and additional procedures down the line, and at least one study found that the risk of implant failure was higher than with conventional plates."

An excellent approach
Dr. Adams suggested that intramedullary fixation is often an excellent approach for certain metacarpal shaft fractures. It is ideal for transverse shaft fractures and avoids periosteal stripping at the fracture site. A single pin may be adequate, or multiple smaller pins using a bouquet technique may be required.

"There are purpose-made devices," she noted, "but I'm frugal, so I tend to make my own, using 0.062 K-wire or multiple smaller K-wires. I make a longitudinal incision at the base of the metacarpus, use a burr awl to create an opening in the base of the metacarpal, and pass the pin from proximal to distal. You can use single pins, but I usually prefer more than one for increased rotational stability."

Dr. Adams noted that K-wires are low-tech, inexpensive, work quite well, and can be removed in the office. She prefers to use them when the adjacent digit is not fractured. However, she noted the disadvantage of possible pin site complications.

Finally, Dr. Adams addressed the issue of return to play, which she noted can be controversial. Among high-level athletes, evidence suggests high rates of satisfaction and low complication rates even with early return to play. However, there is limited literature on the topic and no universal agreement. She recommends balancing healing time against the activity needs of the patient, with the caveat that when dealing with pediatric patients, all treatment must be approached with their long-term interests in mind.

Peter Pollack is the electronic content specialist for AAOS Now. He can be reached at ppollack@aaos.org

Bottom Line

  • Rotational deformity may play a key role in the treatment approach to metacarpal shaft fractures.
  • Shortening and angulation at the neck may be well tolerated, particularly in the ulnar digits.
  • Intramedullary fixation may often be an excellent treatment approach.
  • Absorbable plates may not be ready for "prime time."

Reference

  1. Strauch RJ, Rosenwasser MP, and Lunt JG. Metacarpal shaft fractures: the effect of shortening on the extensor tendon mechanism. J Hand Surg Am 1998 May;23(3):519-23. https://www.ncbi.nlm.nih.gov/pubmed/9620194/