Executive Editor: Jörg Auer

Authors: Jeffrey Watkins

Phalanges Middle phalanx, Biaxial eminence

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Glossary

1 Principles top

Complete cartilage removal... enlarge

Complete cartilage removal

Complete cartilage removal is important to provide for maximum contact between the opposing subchondral bone plates. With compression, generated by the fixation technique, frictional forces are generated between the subchondral bone plates, which maximizes strength and stability of the fixation, providing maximum patient comfort.


Plate placement enlarge

Plate placement

The implant positioning in the middle phalanx is just distal to the proximal articular surface. The distal end of the plates should not impinge on the proximal attachment of the distal interphalangeal joint capsule and should be positioned abaxially to avoid the extensor process.The distal plate screws should engage a substantial portion of the palmar/plantar eminence fragments to provide maximum strength of the fixation.


It is important, that the screws through the distal aspect of the plates engage the eminence fragments enlarge

Further considerations

It is important, that the screws through the distal aspect of the plates engage the eminence fragments to provide for reestablishment of the palmar/plantar support and to reduce the fractures on the palmar/plantar aspect of the middle phalanx.

Two plates are necessary to neutralize the bending forces acting across the pastern joint and provide transarticular compression to encourage arthrodesis.

2 Reduction and fixation of the larger eminence fragment top

In most cases, the proximal articular... enlarge

Reduction

In most cases, the proximal articular surface of the middle phalanx is reconstructed with the joint dorsally luxated to allow direct visualization of the major fracture fragments.
Alignment is generally achieved through a combination of flexion and extension of the digit and placement of large pointed reduction forceps to engage the major eminence fragments from dorsal to palmar/plantar.


Once the larger eminence... enlarge

Fixation of the larger eminence fragment

Once the larger eminence fragment is reduced a 4.5 mm cortex screw is placed in lag fashion from dorsal to palmar/plantar to compress the reduced fracture fragments.

3 Plate selection and preparation top

Show plate enlarge

Plate selection

A combination of PIP plates and/or 4-5 hole narrow LCP are used in most cases. Other plate constructs have been used successfully, including narrow, 4.5 mm DCPs and LC-DCPs.
The technique for fixation with DCP or LC/DCP is described for uniaxial eminence fractures as an example. For more details click here.


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Plate preparation

The plates are contoured to approximate the dorsal surface of the distal proximal phalanx and proximal middle phalanx with the stacked combi-hole into the plate positioned over the proximal end of the middle phalanx.
The distal end of the plate is bent slightly to ensure that the middle phalangeal plate screw is directed into the major substance of the eminence fragment.

4 Reduction and plate fixation top

The second eminence fracture... enlarge

Application of the first plate

The second eminence fracture is reduced with a pointed reduction forceps. Once reduced, either a 5.5 mm or a 5.0 mm locking head screw is positioned through the distal hole of the first plate. This screw is located abaxial to the first screw and engages the major eminence fracture fragment that has not been stabilized by the axial lag screw.


The second plate is applied... enlarge

Application of the second plate

The second plate is applied on the opposite abaxial side and, the distal plate screw should engage the corresponding or ipsilateral eminence fragment.


The middle and proximal phalanges... enlarge

Fixation to the proximal phalanx

The middle and proximal phalanges are realigned and the plates fixed to the proximal phalanx using 5.5 mm cortex screws placed in a load position in the second hole proximal to the joint.


The remaining holes are filled... enlarge

Insertion of remaining screws

The remaining holes are filled with locking screws with both juxta-articular locking screws placed bicortically and the proximal most locking screw in a four-hole plate monocortically.


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Confirmation

The final construct configuration is checked with appropriate imaging to ensure appropriate length and positioning of all implants.

It is important that screws of appropriate length are used and that they do not protrude significantly beyond the palmar/plantar cortex of the proximal and middle phalanges.


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v1.3 2013-11-20