Treatment of Recurrent Instability.
Last updated Thursday, February 10, 2005
Figure 6 - Reattachment of the glenohumeral ligaments, capsule, and labrum to the rim of the glenoid Figure 7 - Axillary incision Figure 8 - Exposing the subjacent subscapularis tendon and lesser tuberosity Figure 9 - A blunt elevator is inserted through the interval into the joint Figure 10 - Posterolateral humeral head defect Figure 11 - Bankart lesion Figure 12 - The anterior, non-articular aspect of the glenoid lip is roughened with a curette or a motorized burr. Figure 13 - Glenoid roughening Figure 14 - A 1.8-mm drill is used to make holes on the articular aspect of the glenoid Figure 15 - Continuity is established between the corresponding slots and holes Figure 16 - Sutures are passed through the glenoid lip Figure 17 - Securing the capsule to the glenoid lip Figure 18 - Securing the glenoid lip Figure 19 - Tying the sutures Figure 20 - The labrum and medial edge of the capsule are brought up on the glenoid lip Figure 22 - X-Ray of bone block Figure 23 - X-Ray of bone block Surgical techniqueGoal of surgery The goal of surgical management of traumatic anterior inferior
glenohumeral instability is the safe, secure and anatomic repair of the
traumatic lesion, restoring the attachment of the glenohumeral
ligaments, capsule, and labrum to the rim of the glenoid from which
they were avulsed. By assuring that reattachment occurs to the rim, the
effective depth of the glenoid is restored. This anatomic reattachment
should reestablish not only the capsuloligamentous check rein but also
the fossa-deepening effect of the glenoid labrum. Unnecessary steps are
avoided, such as coracoid osteotomy and splitting the subscapularis
from the capsule. No attempt is made to modify the normal laxity of the
anterior capsule in the usual case of traumatic instability. The repair
must be secure from the time of surgery so that it will allow the
patient to resume activities of daily living while the repair is
healing. Such a secure repair allows controlled mobilization, thereby
minimizing the possibility of unwanted stiffness. The tools needed for
this repair are simple and commonly available.
Anesthesia The procedure is performed under a brachial plexus block or a general
anesthetic. The glenohumeral joint is examined under anesthesia.
Although this examination rarely changes the procedure performed, it
provides helpful confirmation of the diagnosis.Positioning the patient The patient is positioned in a slight head-up position
(approximately 20 degrees) with the shoulder off the edge of the
operating table. This position provides a full range of humeral and
scapular mobility, and, if necessary, access to the posterior aspect of
the shoulder. The neck, chest, axilla, and entire arm are prepared with
iodine solution.
The procedure The shoulder is approached through the dominant anterior axillary
crease which is marked prior to the application of an adherent,
transparent plastic drape to facilitate a cosmetically acceptable scar.
(Harryman, 1992)
The skin is incised and the subcutaneous tissue are undermined up to
the level of the coracoid process, which is then used as a guide to the
cephalic vein and the deltopectoral groove. The groove is opened by
spreading with the two index fingers medial to the cephalic vein. A
neurovascular bundle (a branch of the thoracoacromial artery and the
lateral pectoral nerve) is commonly identified in the upper third of
the groove;(Grant, 1972) this bundle is cauterized and transected. It
is not necessary to release the upper pectoralis major, unless a
prominent falciform border extends up to the superior extent of the
bicipital groove.
The clavipectoral fascia is incised just lateral to the short head
of the biceps, up to but not through the coracoacromial ligament,
entering the humeroscapular motion interface and exposing the subjacent
subscapularis tendon and lesser tuberosity. The axillary nerve is
routinely palpated as it crosses the anteroinferior border of the
subscapularis. At this point it is useful to insert a self-retaining
retractor, with one blade on the deltoid muscle and the other on the
coracoid muscles. Care must be taken to assure the medial limb of this
retractor does not compress the brachial plexus. Rotating the arm from
internal to external rotation reveals, in succession, the greater
tuberosity, the bicipital groove, the lesser tuberosity, and the
subscapularis. The anterior humeral circumflex vessels can usually be
protected by bluntly dissecting them off of the subscapularis muscle at
its inferior border. The interval between the supraspinatus and
subscapularis tendons is identified by palpation, and a blunt elevator
is inserted through this interval into the joint. This elevator brings
the upper subscapularis into the incision. With care to protect the
tendon of the biceps, the subscapularis tendon and subjacent capsule
are then incised together approximately 1 cm medial to the lesser
tuberosity, beginning at the superior rounded edge of the tendon. A tag
suture is placed in the upper rolled border of the subscapularis to
mark it for subsequent repair. The incision is then extended inferiorly
to the level of the anterior circumflex humeral vessels. It is
important that the incision through the subscapularis tendon leaves
strong tendinous material on both sides of the incision to facilitate a
secure repair at the conclusion of the procedure.
Without separating them, the subscapularis tendon and anterior
shoulder capsule are retracted medially, providing an excellent view of
the joint. If necessary for greater exposure, the joint capsule may be
further divided parallel to the upper rolled border of the
subscapularis. The biceps tendon is inspected and note taken of the
integrity of the transverse humeral ligament. Particularly in patients
over 40 years of age the shoulder is inspected for evidence of rotator
cuff tears. In traumatic anterior instability, a posterolateral humeral
head defect is usually palpable by passing an index finger over the top
of the humeral head. If the humeral head defect is so large that it
contributes to instability in functional positions, anterior capsular
tightening may be necessary to keep the defect from entering the joint
on external rotation.
The capsule and subscapularis are retracted together medially and a
humeral head retractor is placed so that it leans on the posterior
glenoid lip and pushes the humeral head posterolaterally. This reveals
the anterior inferior glenoid lip from which the labrum and capsule are
avulsed in the great majority of patients with anterior traumatic
instability. The labrum usually remains attached to the capsular
ligaments but may remain on the glenoid side of the rupture, may be a
separate ("bucket handle") fragment, or may be absent. Occasionally
flimsy attempts to heal the lesion will temporarily obliterate the
defect. However, in these cases a blunt elevator will easily separate
the capsule from the glenoid lip, revealing the typical lesion in the
anterior-inferior quadrant of the glenoid. A spiked retractor is then
placed through the capsular avulsion to expose the glenoid lip. The
glenohumeral joint is inspected thoroughly for loose bodies, defects of
the bony glenoid, and loss of cartilage from the remaining anterior
glenoid.
The reconstruction of the capsulolabral detachment from the glenoid
is necessary and sufficient for the surgical management of most cases
of traumatic instability. This repair is carried out from inside the
joint, without needing to separate the capsule from the subscapularis
muscle and tendon. The glenoid is well exposed by a humeral head
retractor laterally and a sharp-tipped levering retractor inserted
through the capsular defect onto the neck of the glenoid. Bucket handle
or flap tears of the glenoid labrum. (Adams, 1891; Barrett, 1971) are
preserved for incorporation into the reconstruction of the glenoid lip.
The anterior, non-articular aspect of the glenoid lip is roughened
with a curette or a motorized burr, taking care not to compromise the
bony strength of the glenoid lip. A 1.8-mm drill is used to make holes
on the articular aspect of the glenoid 3 to 4 mm back from the edge of
the lip to ensure a sufficiently strong bony bridge. We place these
holes 5 to 6 mm apart; thus the size of the defect dictates the number
of holes used for the reconstruction. Corresponding slots are placed on
the anterior non-articular aspect of the glenoid.Using a 000 angled
curette, continuity is established between the corresponding slots and
holes.
A strong #2 absorbable braided suture is passed through the holes in
the glenoid lip using a trocar needle and an angled needle holder.
After each suture is placed through the glenoid lip, the integrity of
the bony bridge is checked by a firm pull on the suture.
When sufficient sutures have been placed to span the capsular
defect, the sharp-tipped levering retractor is removed and replaced by
a right-angled retractor positioned to reveal the trailing medial edge
of the avulsed capsule. This edge is most easily identified by tracing
the intact labrum around the glenoid to its point of detachment at the
Bankart defect. Next, using the trocar needle, the anterior end of the
suture (the limb exiting the anterior non-articular aspect of the
glenoid lip) is passed through the trailing medial edge of the capsule,
taking care to incorporate the glenoid labrum, if present, and the
strong medial edge of the capsule. No more capsule is taken than
necessary to obtain a firm purchase. This prevents unwanted tightening
of the anteroinferior capsule. In larger glenohumeral ligament
avulsions, the detached medial edge of the capsule tends to sag
inferiorly; in this situation an effort is made to pass each suture
through the capsule slightly inferior to the corresponding bony hole in
the glenoid lip. Thus, when the sutures are tied, the inferiorly
sagging medial capsule is repositioned anatomically.
Once the sutures have been passed through the capsule, they are tied
so that the labrum and medial edge of the capsule are brought up on the
glenoid lip to restore the fossa-deepening effect of the labrum.
(Lazarus, Sidles, Harryman et al, 1996) The knots are tied so that they
come to rest over the capsule, rather than on the articular surface of
the glenoid. Because they lie over soft tissue, these sutures do not
present a mechanical problem, even though they lie within the joint.
Once these sutures are tied, the smooth continuity between the
articular surface of the glenoid fossa and the capsule should be
reestablished along with a reconstructed labrum-like structure. No
stepoff or discontinuity in the capsule should be present. If a
substantial anterior capsular defect exists anywhere but at the normal
subcoracoid recess, it is closed.
Approximately 10 per cent of TUBS patients have fractures or
deficiencies of the anterior bony lip of the glenoid. At the initial
surgery, it usually seems reasonable to attempt reconstruction by
attaching the avulsed anterior capsule to the lip of the remaining
glenoid articular surface. Anterior glenoid deficiencies greater than
33 per cent or those associated with previous surgical failure may
require that the repair of the capsule to the edge of the remaining
articular cartilage be backed up by the reconstruction of the lip of
the glenoid using an iliac bone block. The iliac bone block is
contoured flush with the normal glenoid curvature and held to the
anterior glenoid with two screws placed securely and well away from the
humeral joint surface. By placing the graft outside the repaired
capsule, it becomes covered with periosteum or joint capsule preventing
direct contact with the humeral head.
At the conclusion of the surgical repair the capsule and
subscapularis tendon are repaired anatomically to their mates at the
lesser tuberosity, using the upper rolled border of the subscapularis
as a reference. At least six sutures of number two braided
non-absorbable suture are used in this repair, assuring good bites in
both the medial and lateral aspects of the repair. If the tissue on the
lateral side is insufficient, the tendon and capsule are repaired to
drill holes at the base of the lesser tuberosity. A strong
subscapularis and capsular repair is essential to early rehabilitation.
The shoulder should have at least 30 degrees of external rotation at
the side after the subscapularis/capsular repair. Once this repair has
been completed, the shoulder stability is examined. If excessive
anterior laxity remains, for example external rotation in excess of
45° (which is rarely the case), the lateral capsular and
subscapularis reattachment may be advanced laterally or superolaterally
as desired.
In the highly unusual situation in which a shoulder with the TUBS
syndrome is found not to have capsular detachment, the shoulder should
be inspected carefully for mid substance capsular defects. If none is
found, the anterior instability may be treated by reefing the anterior
capsule and the subscapularis tendon. Shortening these structures by 1
cm limits external rotation of the humerus by approximately 20 degrees.
Generally, restricting external rotation to 30 degrees at the operating
table will permit a very functional shoulder after rehabilitation is
complete. If the patient has marked anterior ligamentous laxity,
proportionately greater anterior tightening may be necessary, although
the surgeon must be certain that the patient does not have
multidirectional laxity before a unidirectional tightening is carried
out.
A standard wound closure is carried out, using a subcuticular suture, which is removed at three days.
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