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Authors of section


Jonas Andermahr, Michael McKee, Diane Nam

Executive Editor

Joseph Schatzker

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ORIF - Lag screw fixation

1. Principles/Introduction

In a multifragmentary fracture of the glenoid fossa, the small fragments are often too small to fix with the standard 3.5 conventional/cannulated screws. Typically, the following mini-fragment screws are then used:

  • Conventional 2.0 or 2.7 lag screws
  • Headless 2.4 screws (cannulated)

Headless screws are preferable where fixation involves putting them through capsule or labrum.

In addition, they are the smallest cannulated screw system.

orif lag screw fixation

In fractures of the glenoid rim where the glenoid fragments are too small to fix with screws, the glenoid labrum still needs to be reduced and fixed to obtain a stable shoulder. This can be performed using suture anchors.

glenoid fossa partial articular posterior multifragmentary

2. Patient preparation

Depending on the approach, the patient may be placed in the following positions:

3. Approach

An anterior approach to the shoulder joint is easier to perform. It may therefore be easier to fix large posterior fragments through an anterior approach.

In a posterior fracture dislocation, the anterior deltopectoral approach is chosen because it offers better dual opportunities, not only to restore posterior lesions but also allows restoration of humeral head impaction lesions which involve the anterior part of the head.

orif lag screw fixation

If the fragments are small and lag screw fixation from anterior is not possible, a posterior approach and fixation is carried out.

4. Reduction

One K-wire is partially inserted in the main fragment and is used as a joystick for reduction. If conventional screws are to be used for fixation, make sure that the fragment is big enough to take the head. Otherwise use the headless screw.

K-wires and screws must be extra articular.

orif lag screw fixation

When reduction is completed, insert the K-wires further to secure temporary fixation of the fracture.

orif lag screw fixation

The size of the fragments determines their fixation. At times, if the fragment is very small, a K-wire will serve as its definitive fixation. Otherwise, use either the headless screw or the small fragment cannulated screws.

Depending on the size of the main fragments, one or two appropriate length screws are then inserted…

orif lag screw fixation

... and the K-wires are removed. Smaller fragments may be keyed into place and held by the larger fragments.

Sometimes one must resort to an anchor if the fragment is very small as well as a small spring plate.

glenoid fossa partial articular posterior multifragmentary

Use the image intensifier to check your reduction prior to any definitive fixation. At the end, check once again with the image intensifier to make sure that there is no intra articular metal.

orif lag screw fixation

5. Aftercare

The aftercare can be divided into 4 phases:

  1. Inflammatory phase (week 1–3)
  2. Early repair phase (week 4–6)
  3. Late repair and early tissue remodeling phase (week 7–12)
  4. Remodeling and reintegration phase (week 13 onwards)

Full details on each phase can be found here.