The patient is placed in the beach-chair position. A reusable arm holder,
through which 2 kg of traction is applied, maintains the elbow at a right
angle while allowing free rotation of the shoulder joint
(Fig. 1). The elbow is
carefully padded and protected. This setup facilitates control of external
rotation of the shoulder during the operation.
One posterior portal, 1 to 2 cm inferior to the posterior aspect of the
acromion and medial to the deltoid muscle, and two anterior portals, one
anterosuperior (between the coracoid process and the anterior aspect of the
acromion) and one anteroinferior (1.5 to 2 cm inferior to the coracoid
process), are utilized (Fig.
2).
The anteroinferior portal is used specifically for the trans-subscapular
approach and is placed after preparation of the labrum and the glenoid rim,
which is performed through the anterosuperior portal.
A working cannula is placed in the anterosuperior portal.
Intra-articularly, the traumatized glenoid labrum and the capsule are detached
from the glenoid rim with a sharp dissector. The glenoid rim is then abraded
with use of a 4.5-mm burr, and two or three shallow notches are created
anteriorly, at approximately five o'clock, three-thirty, and two o'clock (in a
right shoulder) (Figs. 3-A and
3-B).
At this point in the operation, the surgeon moves from a posterior to an
anterior position relative to the patient. A 10-cm-diameter roll is placed in
the axilla to act as a fulcrum in order to facilitate access to the
anteroinferior region of the shoulder joint and the glenoid rim. This lateral
distraction effect on the proximal part of the humerus can be augmented easily
by pressing the elbow toward the chest over the axillary roll.
The patient's arm is then placed in 20° to 30° of external rotation
(Figs. 4-A and 4-B).
A metal sheath with a blunt trocar is introduced through the anteroinferior
portal; the instrument is initially directed toward the lesser tuberosity.
After making contact with the insertion of the subscapularis tendon, the
trocar is redirected medially with the application of gentle pressure
(Fig. 5). As the trocar is
pushed through the subscapularis muscle medial to its tendinous attachment,
the bulge of the capsule is visualized from within the joint with the
arthroscope.
This "slalom approach," as we have called it because of the
side-to-side figure-of-S movement, protects the nearby musculocutaneous and
axillary nerves from injury because of its more lateral penetration of soft
tissues anterior to the shoulder, minimizes trauma to the rotator cuff, and
safely facilitates separation of the capsule from the subscapularis. A
Kirschner wire is introduced through the trocar, and the capsule is
perforated. The capsule can now be manipulated as the surgeon determines the
appropriate tension prior to definitive repair of the capsule back to the
glenoid rim (Figs. 6-A and
6-B).
The capsule is reapproximated to the most inferior notch on the glenoid
rim, and a capsular shift is accomplished by advancing the capsular tissue in
a superior and medial direction. The blunt trocar is then removed, and the
serrated edge of the cannula is used to temporarily hold the capsule in
position. A cannulated 2.7-mm drill and its 1.1-mm guidewire are introduced
through the cannula, with the guidewire protruding about 1 mm from the tip of
the drill. With use of the tip of the guidewire, first the capsule and then,
if possible, the dislocated labrum are pinched. The drill is then manipulated
through the pinched soft tissue and is placed in the osseous notch, close to
the rim of the glenoid articular surface, under arthroscopic control. The
drill is advanced to a maximum depth of 18 mm, after which a stop limits its
further penetration (Figs. 7-A and
7-B).
The locking mechanism is released, leaving the guidewire in place and
allowing removal of the drill. This maneuver prevents the capsule from
displacing; a tack implant is then introduced over the guidewire and is seated
into the glenoid rim with use of a cannulated driver
(Figs. 8-A and 8-B). The head
of the implant is seated outside the joint and the capsule but deep to the
fibers of the subscapularis muscle (Fig.
9).
After placement of this first tack, the roll in the axilla is removed and
the procedure is repeated, with a second tack securing the capsule to the
middle notch. If the labral detachment extends cephalad to the equator of the
glenoid, and the second tack does not secure the whole lesion, an additional
repair of the labrum is performed from within the joint with use of one or two
more tacks cephalad to the level of the equator of the glenoid (Figs.
10-A, 10-B, and
11).
CRITICAL CONCEPTSINDICATIONS:Unidirectional posttraumatic anterior instability of the shoulder jointCONTRAINDICATIONS:Multidirectional, nontraumatic instabilities of the shoulderOsseous defects or bone fragments in the anterior part of the glenoid
exceeding 10% of the glenoid
surface4Weak capsular tissues allowing the head of the tack to perforate through
the capsule after fixation to the glenoid rimPITFALLS:As the surgeon performs the critical part of the procedure standing
opposite the arthroscope, it is important to have an assistant who is familiar
with shoulder arthroscopy.The direction of the drilling must be perpendicular to the glenoid rim. If
the direction is too medial the drill will slip toward the glenoid neck, and
if the direction is too lateral there is risk of perforating the glenoid
articular surface when the tack is introduced.One additional critical stage of the procedure is removing the drill from
the glenoid rim. The unthreaded guidewire must be retained in position inside
the drill-hole to facilitate subsequent placement of the tack. It is helpful
to maintain the wire in place with a second guidewire that is placed within
the cannulated drill abutting the first while the cannulated drill is removed
over the two wires.When the tack is introduced, the opening of the cannula must be deep to the
subscapularis muscle fibers and outside the capsule; otherwise, the tack can
get caught in the subscapularis muscle or even can be tethered in the soft
tissues.If the capsular tissue is too weak, the tack may cut through the capsule.
This is a rare occurrence in posttraumatic cases (see Contraindications).AUTHOR UPDATE:Because of the disappointing long-term results of the technique as
described in the original scientific article, it has been modified
substantially. Today we most commonly use knotless anchors at the most
cephalad (three-thirty and two o'clock) positions because it is easier to
balance the capsulorrhaphy in this part of the shoulder with these
implants.For this modified technique, a second working cannula directly anterior to
the long head of the biceps tendon is introduced for suture management. A
suture hook is used to deliver the sutures through the capsule and the labrum,
and two self-locking suture anchors are used to secure the tissue to the
anterior aspect of the glenoid rim along its middle and upper portions
(Figs. 12-A and 12-B). We
continue to use the tack in the five o'clock position as described in the
present report.We believe that there is an advantage associated with this extra-articular
technique as it provides for a substantial decrease in the volume of the
anterior capsule and produces only one minor hole in the capsule at the repair
site in the anterior inferior part of the shoulder. One additional advantage
as seen in the present study is that the polymer implants are more fully
absorbed after extra-articular placement. In the event that future revision
surgery is needed, it is important not to have cysts in the most important
inferior part of the glenoid rim. The formation of cysts, at least in the
short term, in the anterior aspect of the glenoid after using absorbable
implants has been reported
previously5,6.
Furthermore, it is our opinion that the degenerative changes seen in the long
term in the present study do not depend on whether the implant is placed
intra-articularly or extra-articularly.
CRITICAL CONCEPTS
INDICATIONS:
Unidirectional posttraumatic anterior instability of the shoulder joint
Unidirectional posttraumatic anterior instability of the shoulder joint
CONTRAINDICATIONS:
Multidirectional, nontraumatic instabilities of the shoulderOsseous defects or bone fragments in the anterior part of the glenoid
exceeding 10% of the glenoid
surface4Weak capsular tissues allowing the head of the tack to perforate through
the capsule after fixation to the glenoid rim
Multidirectional, nontraumatic instabilities of the shoulder
Osseous defects or bone fragments in the anterior part of the glenoid
exceeding 10% of the glenoid
surface4
Weak capsular tissues allowing the head of the tack to perforate through
the capsule after fixation to the glenoid rim
PITFALLS:
As the surgeon performs the critical part of the procedure standing
opposite the arthroscope, it is important to have an assistant who is familiar
with shoulder arthroscopy.The direction of the drilling must be perpendicular to the glenoid rim. If
the direction is too medial the drill will slip toward the glenoid neck, and
if the direction is too lateral there is risk of perforating the glenoid
articular surface when the tack is introduced.One additional critical stage of the procedure is removing the drill from
the glenoid rim. The unthreaded guidewire must be retained in position inside
the drill-hole to facilitate subsequent placement of the tack. It is helpful
to maintain the wire in place with a second guidewire that is placed within
the cannulated drill abutting the first while the cannulated drill is removed
over the two wires.When the tack is introduced, the opening of the cannula must be deep to the
subscapularis muscle fibers and outside the capsule; otherwise, the tack can
get caught in the subscapularis muscle or even can be tethered in the soft
tissues.If the capsular tissue is too weak, the tack may cut through the capsule.
This is a rare occurrence in posttraumatic cases (see Contraindications).
As the surgeon performs the critical part of the procedure standing
opposite the arthroscope, it is important to have an assistant who is familiar
with shoulder arthroscopy.
The direction of the drilling must be perpendicular to the glenoid rim. If
the direction is too medial the drill will slip toward the glenoid neck, and
if the direction is too lateral there is risk of perforating the glenoid
articular surface when the tack is introduced.
One additional critical stage of the procedure is removing the drill from
the glenoid rim. The unthreaded guidewire must be retained in position inside
the drill-hole to facilitate subsequent placement of the tack. It is helpful
to maintain the wire in place with a second guidewire that is placed within
the cannulated drill abutting the first while the cannulated drill is removed
over the two wires.
When the tack is introduced, the opening of the cannula must be deep to the
subscapularis muscle fibers and outside the capsule; otherwise, the tack can
get caught in the subscapularis muscle or even can be tethered in the soft
tissues.
If the capsular tissue is too weak, the tack may cut through the capsule.
This is a rare occurrence in posttraumatic cases (see Contraindications).
AUTHOR UPDATE:
Because of the disappointing long-term results of the technique as
described in the original scientific article, it has been modified
substantially. Today we most commonly use knotless anchors at the most
cephalad (three-thirty and two o'clock) positions because it is easier to
balance the capsulorrhaphy in this part of the shoulder with these
implants.
For this modified technique, a second working cannula directly anterior to
the long head of the biceps tendon is introduced for suture management. A
suture hook is used to deliver the sutures through the capsule and the labrum,
and two self-locking suture anchors are used to secure the tissue to the
anterior aspect of the glenoid rim along its middle and upper portions
(Figs. 12-A and 12-B). We
continue to use the tack in the five o'clock position as described in the
present report.
We believe that there is an advantage associated with this extra-articular
technique as it provides for a substantial decrease in the volume of the
anterior capsule and produces only one minor hole in the capsule at the repair
site in the anterior inferior part of the shoulder. One additional advantage
as seen in the present study is that the polymer implants are more fully
absorbed after extra-articular placement. In the event that future revision
surgery is needed, it is important not to have cysts in the most important
inferior part of the glenoid rim. The formation of cysts, at least in the
short term, in the anterior aspect of the glenoid after using absorbable
implants has been reported
previously5,6.
Furthermore, it is our opinion that the degenerative changes seen in the long
term in the present study do not depend on whether the implant is placed
intra-articularly or extra-articularly.