Proximity of Metacarpal Plates to Adjacent Joints Increases Risk of Implant Removal

Two views of X-ray of human hand with fracture in fifth metacarpal highlighted red

Internal fixation with plates and screws is commonly used to treat isolated metacarpal fractures. It has the theoretical advantage of stable osteosynthesis, which allows for early digital motion. However, there is potential for adhesion of the extensor tendons to the plate, which can cause stiffness and requires subsequent hardware removal.

Dafang Zhang, MD, a specialist in the Department of Orthopaedic Surgery at Brigham and Women’s Hospital, Phillip T. Grisdela, MD, a resident in the department, and colleagues studied factors associated with implant removal in this setting. In The Journal of Hand Surgery, they caution that shorter distances between the plate and adjacent metacarpophalangeal and carpometacarpal joints, as measured on radiography, were independently associated with implant removal.

Methods

The team queried a database of patients who underwent open metacarpal fracture treatment with a plate-and-screw construct between January 1, 2000, and April 30, 2019. To study a homogeneous group with comparable soft tissue injury, they included only 138 patients with single-digit (non-thumb), isolated, displaced metacarpal fractures.

The final cohort was 81 patients who had the plate-and-screw construct removed or had at least two years of follow-up without removal of the hardware. The mean length of follow-up was eight years (range, 82 days to 19 years).

Results

23 patients (28%) underwent implant removal by their final follow-up visit: three because of an infection, two because of hardware failure, and the others because of stiffness or other symptoms attributed to the hardware.

The mean time until implant removal was 16 months. 50% of plates positioned ≤10 mm from the metacarpophalangeal (MCP) joint and 30% of plates positioned ≤5 mm from the carpometacarpal (CMC) joint were removed within two years after surgery.

In multivariable analysis, factors independently associated with implant removal were:

  • The distance between the distal-most extent of the plate and the MCP joint of the affected digit (OR for each increase by 1 mm, 0.86)
  • The distance between the proximal-most extent of the plate and the CMC joint (OR for each increase by 1 mm, 0.96)
  • Current smoking (OR, 5.35)

Advice for Surgeons

Placement of plate-and-screw constructs is principally dictated by the fracture pattern, and priority should be given to stable fixation. However, it’s important to stay aware of the implant’s proximity to the joints and intraoperatively adjust its position where possible.

For treating fractures close to the MCP or CMC joint, other methods of fixation, such as percutaneous pinning or intramedullary screw fixation, may be preferable.

In some cases, it will be prudent to counsel patients about the higher risk of subsequent implant removal when periarticular metacarpal plating is performed.

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