1 Treatment principles topenlarge
A1.3 fractures are glenohumeral dislocations with associated tuberosity fractures. Almost all of these involve the greater tuberosity and those will be discussed here.
Reduction of the glenohumeral joint should be performed as an emergency procedure. Once the glenohumeral joint is reduced, A1.3 becomes an A1.2 or even an A1.1 fracture and is treated accordingly.
The greater tuberosity fragment tends to be displaced superiorly and posteriorly due to the pull of the rotator cuff (supraspinatus and infraspinatus tendon). If the greater tuberosity heals with displacement (5 mm or more), it may impinge upon the coracoacromial arch, limiting motion, and producing pain. In this position, it provides a shorter lever arm for the supra- and infraspinatus tendons, and thus weakens them.
2 Reduction of the glenohumeral joint top
Reduction of the glenohumeral joint should be performed as an emergency procedure.
There are various techniques to reduce the glenohumeral joint.
- Combined traction technique
- Modified Stimson technique
Unless reduction is carried out very soon after dislocation, analgesia or anesthesia are typically necessary. An initial attempt with conscious sedation may succeed. If not, general anesthesia with complete muscle relaxation may be required. If closed reduction is unsuccessful, open reduction may be necessary.
Combined traction technique
The patient is placed supine on a table. The injured arm is pulled longitudinally and, with the help of a second person, laterally as well.
A sheet around the chest may be used for counter-traction.
Modified Stimson technique
In the modified Stimson technique the patient is placed prone with the shoulder beyond the lateral edge of the table. A weight is attached to the wrist. Over time the musculature becomes fatigue and/or relaxed so that the humeral head reduces spontaneously, or with gentle manipulation.
Confirmation of reduction
The reduction is confirmed by x-ray. One should pay special attention to obtain a true AP view in order to confirm the glenohumeral reduction. Look carefully at the greater tuberosity, and determine its degree of displacement accurately.
3 Reduction and temporary fixation of the greater tuberosity topenlarge
Reduction of the greater tuberosity
One can try to reduce the greater tuberosity closed, though this is unlikely to succeed. A manipulative reduction with a threaded pin through a stab incision under image intensification often works. If not, open reduction is required.
Closed reduction maneuver
In a slender patient, with the arm slightly abducted, it may be possible to press the greater tuberosity fragment into position with your thumb.
Under image intensifier control, make a small stab incision over the lateral aspect of the greater tuberosity fragment. Spread the deltoid muscle gently and insert a small elevator, ball-spiked pusher, or hook. To reduce the greater tuberosity, apply the instrument to its upper border and …
… push it into its bed.
Temporary fixation of the greater tuberosity
The K-wire(s) is inserted while the reduction is maintained with the instrument.
Confirmation of reduction
Reduction and proper placement of the K-wire should be confirmed under image intensifier control.
4 Fixation of the greater tuberosity topenlarge
It is the surgeons preference whether to use 3.5 mm cannulated lag screws (as illustrated) or small fragment screws.
Note: Washers might be advisable with osteoporosis or fragmentations. Generally, they are not preferable as they make the screw heads more prominent and may result in shoulder impingement.
If the greater tuberosity fragment is large, two screws may be used for better fixation.
Note: make sure to avoid the axillary nerve by placing the second screw rather proximal.
Once osteosynthesis is completed remove all K-wires.
Check fixation by image intensification.