An Arthroscopic Coracoclavicular Ligament Reconstruction: A Technique Using Novel Button Devices
The Calvicular Clip
The Sub-Coracoid Clip
An acromioclavicular joint (AC-joint) separation typically occurs after falling on the shoulder. In type III-V dislocations surgical intervention is often considered. A new arthroscopic double bundle coracoclavicular (CC) ligament reconstruction technique using a semitendinosus tendon (ST) autograft has been introduced to treat AC dislocations. The tendinous reconstruction may be used both in acute and chornic cases.
The key element in this technique is the positioning of the hamstring tendon graft. The anterior limb of the graft projects superiorly and replaces the trapezoid ligament. The dorsal limb of the graft is wrapped around the dorsal edge of the clavicle reconstructing the conoid ligament. As the ST graft shares the same drill holes with the temporary fixation apparatus, there is only one 6-mm drill hole in the clavicle and a 4.5-mm drill hole in the neck of the coracoid. This effectively stabilizes the AC- joint and prevents anterior-posterior translation(Fig 1.)
For additional fixation, titanium buttons connected with double number 5 Fiberwire or Fibertape has been utilized.
The Graft Washer has earlier been used as a button on top of the clavicle. A significant problem in the technique was big number 5 Fiberwire or Fibertape knots on top of the clavicular Graft
Washer which caused irritation to the overlying tissues. Sometimes the knots had to be removed due to irritation or even an infection. Furthermore the buttons used underneath the coracoid, sometimes seemed to grind the sutures broken due to movement and friction against the sub- coracoid button.
The devices and the technique
A set of new buttons made of medical titanium was designed. The clavicular button was designed to resemble a paper clip in which the anterior edge forms a loop which dives 5 mm deep into the 6 mm clavicular drill hole (Fig 2.). The implant was named the Calvicular Clip
Fig 2. The Clavicular Clip
The number 5 Fiberwire or Fibertape knot is hidden into the loop (Fig 3.). The loop is pushed into the clavicular drill hole when no protruding knot over the clavicle exists any more (Fig 4.). The metal loop is 2 mm wide and 1 mm thick, which is also enough to squeegee the tendon graft against the bone walls of the drill hole. Therefore, there is no need for an ￼interference screw which also reduces the amount of foreign material needed.
The Sub-Coracoid Button was designed to be a simple ring with a smooth cross-bar. The number 5 Fibertape is attached to the button using a double folded lasso around the cross-bar. Therefore any movement does not introduce any friction to the knot: a fact known for sailors (Fig 5.).
Using these implants the connecting Fiberwire/ Fibertape sutures are projected straight from the sub-coracoid button to the clip-loop. Therefore no funneling shape of the connecting suture-material occurs, risking widening of the clavicular drill hole, as when using the Graft Washer .
The Calvicular Clip comes in three different sizes: 20 mm, 16 mm and 14 mm. The idea is that the clips are long enough to spread the pressure on the bone and therefore reduce risk of a fracture to the bone. The subcoracoid implants com in two types. The Sub-Coracoid Button for single suture attachments, usually when using the tendon graft. The Sub-Coracoid Clip is for double Fibertape attachments in acute cases when the tendon graft is not needed.
￼Fig 3. The knot is sunken into the Clip loop. Note the lack of funnel shape of the sutures.
￼Fig 4. As assembled, the Fiberwire knot is completely hidden under the surface of the clavicular cortex and does not protrude by any means.
￼Fig 5. The double folded loop attachment.
In acute cases The tendinous reconstruction is not always necessary. The Calvicular Clip may also be used without any tendon graft. For example single or double Fibertape may be used (Fig 6.). Then the smallest size of the clips comes into question. The Clavicular Clips come in three different sizes: 20 mm, 16 mm and 14 mm. The idea is that the clips are long enough to spread the pressure on the bone and therefore reduce risk of a fracture to the bone. The Sub-Coracoid Clip allowes the use of double Fibertape fixation.
Fig 6. In acute cases the button may be used also without any tendon graft
The novel buttons made a significant improvement to the CC-ligament reconstruction technique previously described.
The advantages achieved:
1. No protruding heavy knots on top of the clavicle
2. No need for an interference screw
3. No funneling shape of the connecting suture-material
4. Better stability for the sub-coracoid button
5. Simple and easy to handle