Fractures of the metaphysis can be transverse, oblique, or comminuted. Obliquity of the fracture is possible either in the plane visible in the AP view, or in the plane visible in the lateral view. Always confirm the fracture configuration with views in both planes.
Indirect reduction is achieved by traction and digital manipulation. When the fracture is stable, it can be treated nonoperatively. If the fracture is irreducible, ORIF is indicated. Other indications for ORIF are open fractures, or soft-tissue lacerations.
For this procedure the following approaches may be used:
Reduction can be obtained by traction and flexion exerted by the surgeon. Confirm reduction under image intensification. Sometimes, these fractures are stable after reduction if the obliquity is minimal. In this case, nonoperative treatment is indicated.
Direct reduction is necessary when the fracture can not be reduced by traction and flexion, or is unstable. When indirect reduction is not possible, this is usually due to interposition of parts of the extensor apparatus. Use a pointed reduction forceps for direct reduction.
Retain the pointed reduction forceps for preliminary fixation, or insert a 1.0 mm K-wire.
At this stage, after provisional fixation, 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 the fingers in a degree of flexion, and never in full extension. Malrotation may manifest itself by overlap of the flexed finger over its neighbor. Subtle rotational malalignments can often be judged by tilting 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.
Using the tenodesis effect when under anesthesia
Under general anesthesia, the tenodesis effect is used, 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.
4. Plate selection
Fracture oblique in AP view
In case of an oblique fracture as illustrated, there are two options:
1) Minicondylar plate This plate allows axial compression and, because of its lateral placement, the additional insertion of a lag screw across the fracture plane through the plate, improving the quality of fixation. This is the preferred option.
2) T-Plate (adaption plate) In this case, the lag screw must be inserted independently of the plate. The plate is added as a second step and acts as a protection plate. This choice calls for additional soft-tissue dissection for the insertion of the lag screw.
Fracture oblique in the lateral view
If the fracture line is oblique as in this illustration, the same options, but with different implications, apply:
1) Minicondylar plate Because of the lateral plate placement, an additional lag screw has to be inserted independently of the plate. The plate itself has only a protection function.
2) T-plate (adaption plate) The dorsal placement of this plate permits insertion of a lag screw through the plate, in this fracture configuration. This is the preferred choice because of the better stability and lesser soft-tissue dissection.
Bending and contouring the plate
The dorsal surface of the proximal phalanx is gently convex. If the straight T-plate is not adequately contoured to follow this convexity, tightening of the distal screw will open the fracture on its palmar aspect. To overcome this, the plate is slightly overcontoured so that when the distal load screw is tightened, compression is generated evenly over the whole fracture surface.
The plate is placed dorsally on the phalanx, as proximally as possible, without interfering with the joint. Ensure that the plate is centered on the diaphysis in the coronal plane.
Order of screw insertion
The screws are inserted in an order that is determined by the direction of the oblique fracture plane. If the fracture runs from dorsal/proximal to volar/distal, the proximal screws are inserted first, and the distal screws second.
If the fracture line runs from dorsal/distal to volar/proximal, the distal screw is inserted first, and the proximal screws afterwards.
In our example, we will show an oblique fracture running from dorsal/proximal to palmar/distal.
Using a drill guide, carefully drill a first hole for a screw through the transverse part of the plate with a 1.0 mm drill bit. Repeat for the second hole in the transverse part.
Pitfall Be sure not to injure the flexor tendons and digital artery and nerve.
Use a depth gauge to determine screw length.
Screw insertion (proximal)
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. The digital nerve and artery are also at risk of injury. Insert a second screw into the opposite end of the transverse plate section in the same fashion, alternately tightening both screws.
Pitfall: bad plate adaptation
Check for perfect adaptation of the plate to the diaphysis and metaphysis. If it is not perfectly adapted, take out the screws and recontour the plate to avoid fracture displacement or malrotation.
Pitfall: Interfering screws
Conflict of tips of the screws in the transverse part of the plate and joint penetration must be avoided.
Eccentrically drill for distal screw
Use a drill guide and 1.0 mm drill bit to prepare an eccentric hole for the distal plate screw.
Measure screw length
Use a depth gauge to determine screw length.
Screw insertion and compression
Insert the distal, self-tapping screw eccentrically and tighten it, thereby compressing the fracture.
Lag screw insertion
Using a 1.5 mm drill guide, drill a gliding hole in the near (cis) cortex, through the plate as perpendicularly to the fracture line as possible. Then drill a 1.1 mm threaded hole down to the far (trans) cortex. Insert the lag screw and tighten it, giving additional stability to the fracture by applying interfragmentary compression.
Insert an additional neutral diaphyseal screw to complete the fixation.
Protect the digit with buddy strapping to the adjacent finger, to neutralize lateral forces on the finger.
The patient can begin active motion (flexion and extension) immediately after surgery.
See patient after 5 days 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’s restricting finger movement, tenolysis, or arthrolysis become necessary. In these circumstances, take the opportunity to remove the implants.