Compression plate and lag screw

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

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.

This procedure is normally performed with the patient either in a lateral position or in a supine position for posterior access.

For this procedure a posterolateral approach is normally used.

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.

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.

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.

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.

Tightening of the second screw creates compression across the fracture.

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.

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

Postoperatively, the elbow may be placed for a few days in a posterior splint for pain relief and to allow early soft tissue healing, but this is not essential. To help avoid a flexion contracture, some surgeons prefer to splint the elbow in extension.

If drains are used, they are removed after 12–24 hours.

Active assisted motion is encouraged within the first few days including gravity-assisted elbow flexion and extension. Encourage the patient to move the elbow actively in flexion, extension, pronation and supination as soon as possible. Delay exercises against resistance until healing is secure.

Use of the elbow for low intensity activities is encouraged, but should not be painful.

Range of motion must be monitored to prevent soft tissue contracture.

Prevent loading of the elbow for 6–8 weeks.

Monitor the patient to assess and encourage range of motion, and return of strength, endurance, and function, once healing is secure.

The patient is seen at regular intervals (every 10–20 days at first) until the fracture has healed and rehabilitation is complete.

As the proximal ulna is subcutaneous, bulky plates and other hardware may cause discomfort and irritation. If so, they may be removed once the bone is well healed, 12–18 months after surgery, but this is not essential.