Transverse and slightly oblique extraarticular metacarpal fractures may be fixed with compression plating using a T-plate.
Select a plate according to the size of the bone, fracture geometry, and surgeon’s preference. The variable-angle (VA) plate shown on the left can be used for reconstruction of rotational malalignment.
The T-plate is available as a plate with VA locking-head screws. This plate type has the advantage of allowing the insertion of two or three screws at variable angles into the articular block. The rounded plate edges avoid soft-tissue irritation and adhesion.
The plate needs to be contoured to fit the anatomy of the end segment.
Place the patient supine with the arm on a radiolucent hand table.
For this procedure, the following approaches may be used:
Reduction can be obtained by traction and flexion of the metacarpophalangeal (MCP) joint exerted by the surgeon.
Confirm reduction with an image intensifier.
If the fracture reduction appears stable, nonoperative treatment may be considered. In this case, confirming reduction with an image intensifier is essential.
Pointed reduction forceps can be used for reduction.
In very unstable situations, insert a K-wire across the fracture plane for preliminary stabilization.
Be aware that the cortical bone in the metacarpals is dense and thick, so the K-wire tip gets very hot. Irrigation during K-wire insertion is essential to avoid thermal necrosis of the bone around the wire track.
At this stage, it is advisable to check the alignment and rotational correction by moving the finger through a range of motion.
Rotational alignment can only be judged with flexed metacarpophalangeal (MCP) joints. The fingertips should all point to the scaphoid.
Malrotation may manifest by an overlap of the flexed finger over its neighbor. Subtle rotational malalignments can often be judged by a tilt of the leading edge of the fingernail when the fingers are viewed end-on.
If the patient is conscious and the regional anesthesia still allows active movement, the patient can be asked to extend and flex the finger.
Any malrotation is corrected by direct manipulation and later fixed. Flexing the MCP joints while preventing overlap of the fingers will reduce rotational displacement.
Under general anesthesia, the tenodesis effect is used, with the surgeon fully flexing the wrist to produce extension of the fingers and fully extending the wrist to cause flexion of the fingers.
Alternatively, the surgeon can exert pressure against the muscle bellies of the proximal forearm to cause passive flexion of the fingers.
Adapt the plate length to the length of the metacarpal. Avoid sharp edges, which may be injurious to the tendons. There should be at least 3 plate holes distal to the fracture available for fixation in the diaphysis. At least two screws need to be inserted into the diaphysis.
If the plate is perfectly adapted to fit the dorsal surface of the proximal end of the metacarpal, tightening the screws may result in distraction of the metaphyseal fracture, creating a gap in the opposite cortex.
The plate is not contoured, so that it is “overbent” relative to the bone surface. When screws are tightened, compression is then applied across the whole fracture plane including the opposite cortex.
Check for perfect adaptation of the plate to the end segment of the metacarpal.
If it is not perfectly adapted, fracture displacement or malrotation may occur.
Compression plating of a simple transverse or oblique extraarticular fracture follows standard techniques:
Place the plate dorsally on the bone, as proximally as possible, without interfering with the joint.
Ensure that the plate is centered on the diaphysis in the coronal plane.
Keep the plate in place with the atraumatic forceps.
Start with inserting two screws into the articular block:
Carefully drill the first screw hole through the transverse plate part with a 1.5 mm drill bit. The drill bit should engage but not penetrate the far cortex.
Insert the first screw. Ensure that it engages the far cortex but does not protrude into the fibro-osseous flexor digital channel, where the flexor tendons run.
Insert a second screw into the opposite end of the transverse plate section in the same fashion, alternately tightening both screws.
Insert a cortical screw in compression mode in the oblong hole.
After inserting the second screw, check the rotational alignment again.
Prepare and insert another, more proximal diaphyseal locking screw.
Cover the plate with periosteum to avoid adhesion between the tendon and the implant leading to limited finger movement.
Confirm correct rotational alignment by clinical examination.
Image intensification may be used to confirm anatomical reduction and correct placement of implants in two views.
The aftercare can be divided into four phases of healing:
Full details on each phase can be found here.
If there is swelling, the hand is supported with a dorsal splint for a week. This would allow for finger movement and help with pain and edema control. The arm should be actively elevated to help reduce the swelling.
The hand should be splinted in an intrinsic plus (Edinburgh) position:
The reason for splinting the MCP joint in flexion is to maintain its collateral ligament at maximal length, avoiding scar contraction.
PIP joint extension in this position also maintains the length of the volar plate.
After subsided swelling, protect the digit with buddy strapping to a neighboring finger to neutralize lateral forces on the finger.
To prevent joint stiffness, the patient should be instructed to begin active motion (flexion and extension) immediately after surgery.
See the patient after 5 and 10 days of surgery.
The implants may need to be removed in cases of soft-tissue irritation.
In case of joint stiffness or tendon adhesion restricting finger movement, arthrolysis or tenolysis may become necessary. In these circumstances, the implants can be removed at the same time.