Executive Editor: Peter Trafton, Michael Baumgaertner

Authors: Peter Kloen, David Ring

Proximal forearm Ulna, extraarticular, simple

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1 Compression plate principles top

Ulna oblique metaphyseal plate enlarge

In simple oblique fractures, compression can be achieved by combining axial compression with interfragmentary compression using a plate and a lag screw.

2 Plate selection top

Ulna oblique metaphyseal plate – Plate selection enlarge

Use a seven-hole plate. The plate may be a small fragment (3.5 mm) dynamic compression plate (DCP), or limited contact dynamic compression plate (LC-DCP), or (contoured) locking plate (LCP).

Note: In osteoporotic bone there is an indication for the use of a LCP in combination with locking head screws and/or using a longer plate that cradles the olecranon tip.

3 Reduction and preliminary fixation top

Cleaning the fracture site

Expose the fracture ends with minimal soft tissue dissection off the bone. Remove hematoma and irrigate. Reduction can be achieved by direct or indirect reduction techniques.

Ulna oblique metaphyseal plate – Direct reduction enlarge

Direct reduction

Reduce the fracture with the help of small pointed reduction forceps and provisionally fix it with pointed reduction forceps or small K-wires. It is helpful to anticipate plate position when placing reduction forceps and/or K-wires so that they do not interfere with positioning the plate and drilling.

Ulna oblique metaphyseal plate – Reduction using plate enlarge

Reduction with a plate

Fix the contoured plate with one screw to the appropriate fragment. Then reduce the distal fragment against plate and proximal fragment by manipulation of the distal ulna, possibly aided by a clamp outside the fracture site. Final adjustment of the screw may affect reduction, and may be delayed until a screw is placed in the opposite fragment.

4 Creating compression with the plate top

Ulna oblique metaphyseal plate - Compression enlarge

Apply a 3.5 mm cortical screw in neutral position next to the fracture into the proximal fragment.

Note: To avoid the risk of shortening the plate has to be attached to the correct fragment first. The first screw should attach the plate to the fragment which forms an angle >90 degrees beneath the plate. The next screw is inserted into the opposite fragment.

Insert a second 3.5 mm cortical screw in eccentric position next to the fracture into the opposite fragment.

Ulna oblique metaphyseal plate - Compression enlarge

Tightening of the second screw creates compression across the fracture.

5 Insertion of a lag screw top

Ulna oblique metaphyseal plate – Insertion of lag screw enlarge

Further compression can then be achieved by inserting a lag screw through the plate as perpendicularly as possible to the fracture plane, or through the center of the fracture line.

6 Finish plate fixation and final assessment top

Ulna oblique metaphyseal plate – Complete fixation enlarge

Insert the rest of the screws in neutral position.

After fixation of the ulna, assess the range of motion in pronation, supination, flexion and extension. Fixation should be stable and crepitus or restricted motion should be absent. Radiocapitellar and ulnohumeral joints should remain located through a full range of motion.

Check results with image intensifier or x-ray

v2.0 2018-04-30