Two of the most important phases in the operation are the proper drilling of the guide pin through the clavicle and coracoid and the repositioning of the distal clavicle. One might think that these are the simple tasks in the operation – but they are not and they are the fundamental its success.
1. DRILLING THE GUIDE PIN THROUGH THE CLAVICLE AND CORACOID
The most difficult part of the operation
Quite often, drilling of the 2.4-mm guide pin is conducted more or less blindly. The problem is that the C-arch can bend while clenching it, and the guide pin changes direction. It is difficult to aim the drill guide so that the pin penetrates both bones in the ideal direction. Reattempting this process, makes it even more difficult and may result in more than one drill hole being made in the coracoid, which poses risks. The clavicular drill hole should be in the middle of the bone, while the coracoid drill hole should be in the most proximal part and in the middle of the bone.
The drilling must be conducted with visual control. There is mostly fat and connective tissue between the clavicle and coracoid. The coracoid should be exposed sufficiently in order to visualize the drilling site. There is no harm in exposing the coracoid properly. This procedure should be pretty simple but without good visibility it becomes impossible.
If the guide pin seems to miss the coracoid or hits it too laterally or medially, there is a trick to it. The clavicular drill hole may be enlarged with a 3–4-mm cannulated drill, which gives some freedom to move the guide pin to a proper position on the coracoid and finish the drilling. A drill hole of that size poses no risk for clavicular fracture.
THE TRICKS
1. Properly expose of the coracoid for aiming of the drill hole.
2. Enlarge the clavicular drill hole with a 3–4-mm cannulated drill, if needed.
3. Always use needles to position your portals. Do not rely on skin marks.
2. USING THE LASSO-GUIDES
Placing the Curved Lasso-Guide in front of the clavicle and behind the coracoid
Probe with a switching stick along a straight line from the anterior clavicular cortex to the medial coracoid cortex. Check anteriorly that you have an access to the medial coracoid space where the stick is. Stay with the bone. The neural structures are not THAT near, and you should stay above the subscapularis tendon structure. With proper technique, there is no risk for neural or vascular damage. Push the nitinol wire through the guide with the welded end first.
The Curved Lasso-Guide is designed to be used with the stem upright. With the curved tip, slide the device along the medial coracoid cortex until you see the tip of the guide beneath the coracoid. Stay with the bone.
Placing the Curved Lasso-Guide behind the clavicle
Make a blunt passageway with a switching stick behind the clavicle. Push the Curved Lasso-Guide along the posterior cortex and bring it to the coracoid. Push the nitinol wire through with the guide the loop-end first.
Placing the Straight Lasso-Guide though the drill holes
This part is easy. Push the Nitinol wire through the guide the welded end first.
3. RELEASING AND REPOSITIONING THE DISTAL CLAVICLE
The second hardest part of the operation
In chronic cases, the dislocated distal clavicle has been out of use for a long time. The shoulder may have slightly turned anteriorly in its posture and it may be difficult to reduce the distal clavicle without force. There are scars and connective-tissue attachments around the AC joint, and even trapezius muscle fibers may have even pushed underneath the dislocated clavicle. Any interconnective suture will fail or the clavicle will remain elevated if repositioning is done against force.
THE TRICKS
1. A moderate distal clavicle resection is recommended. There is no healthy AC joint left.
2. Release of the pectoralis minor may even be considered, while preparing the coracoid.
3. Attachments around the distal clavicle are released.
4. Mobilize the distal clavicle for easy repositioning.
Once the reduction is conducted and an assistant is holding the distal clavicle down while supporting from the elbow, slack is removed from the interconnective suture and the sutures are tied. The tendon graft is then tensioned, and tied, and secured with sutures.