Previous reports regarding rotator cuff tears have stated that most tears
primarily involve the supraspinatus and not the
infraspinatus1-3.
In the present study, however, the footprint of the supraspinatus was found to
be limited to the anteromedial aspect of the superior facet (the highest
impression) of the greater tuberosity, while that of the infraspinatus
occupied the majority of the greater tuberosity including the anterolateral
aspect of the superior facet (Fig. 1-A and
1-B). These results imply that the infraspinatus tendon may be
involved in small to medium-size rotator cuff tears in a much higher
proportion than previously appreciated.
On the basis of these findings, when we repair full-thickness rotator cuff
tears, we believe that it is very important to bring the posteromedial leaf
anterolaterally and reattach it to the anterior portion of the greater
tuberosity in order to achieve a balanced anatomical repair.
In the present report, we describe the pearls and pitfalls for the balanced
anatomical repair of full-thickness rotator cuff tears on the basis of the
results of our anatomical study.
Arthroscopic Evaluation
The patient is seated in the beach-chair position while under general
anesthesia. A posterior portal is established for the initial assessment of
the glenohumeral joint. An anterior portal through the rotator interval is
established as the working portal for the treatment of intra-articular
lesions. The tear size and the presence of delamination are carefully
determined. The arthroscope is then removed from the glenohumeral joint and is
redirected into the subacromial space. A lateral portal and a posterolateral
portal are also established. Any pathological bursal tissue that impedes
clearance of the space is removed, and an arthroscopic subacromial
decompression is performed to create a flat acromial undersurface. Osteophytes
extending from the inferior part of the acromioclavicular joint and the distal
end of the clavicle are also removed as necessary. The posterolateral portal
is used mainly as a viewing portal in these procedures.
Repair of a Full-Thickness Tear
The tear size and pattern are again evaluated, and the mobility and
repairability of the torn rotator cuff are then estimated.
When a full-thickness tear is repaired, the mobility of the posterior leaf
is typically better than that of the central or anterior leaf. If the tear is
a full-thickness u-shaped tear (Fig. 2,
A), it is easily reduced by pulling the posterior leaf
anterolaterally toward the anterior edge of the greater tuberosity (Figs.
2, B and
3). If the mobility of the
tendon is insufficient in a larger tear, a tendon mobilization procedure is
performed. This includes a capsulotomy at the undersurface of the
supraspinatus and infraspinatus and release of the coracohumeral ligament at
the origin of the posterior aspect of the coracoid process. However, we do not
perform the so-called rotator interval slide. The footprint of the greater
tuberosity is débrided in order to expose cortical bone, but excessive
removal of bone is avoided. A double row repair of the posterior leaf as well
as a side-to-side repair are then performed
(Fig. 2, C), instead
of performing a so-called margin convergence repair.
Advance the Posterior Leaf Anterolaterally
In our anatomical study, the supraspinatus inserted into the most anterior
aspect of the greater tuberosity in normal specimens without a rotator cuff
tear (Fig. 1-A and 1-B). In
addition, in most cadaver specimens with a rotator cuff tear, the
infraspinatus was torn and retracted posteromedially
(Fig. 4). Therefore, the most
critical concept in our procedure is to bring the torn edge of the
infraspinatus anterolaterally and reattach it to the anterior area of the
greater tuberosity (Figs. 2-A, 2-B and
2-C and 3).
Margin Convergence Repair May Not Be the Preferred Procedure
In the repair of the so-called u-shaped tear and some of the crescent-type
tears (Fig. 2-A, 2-B and 2-C),
the margin convergence procedure, which is a direct side-to-side suture of
both the anterior and posterior leafs, is commonly preferred by many
surgeons4. It is
true that the margin convergence procedure is sometimes very effective in
reducing the size of the u-shaped tear. However, on the basis of our
anatomical study, it is evident that the posterior leaf of a so-called
L-shaped tear has retracted posteromedially to alter the final configuration
of the tear to a u-shaped lesion in the chronic stage. Therefore, we think
that surgeons should be more careful in choosing to apply the margin
convergence technique in u-shaped
tears5. We strongly
recommend that the mobility of the torn rotator cuff be evaluated to determine
the repair design because the posterior leaf is normally very mobile compared
with the anterior or the central leaf; this would allow conversion of many
u-shaped lesions to L-shaped tears that are amenable to successful anatomical
repair by mobilization of the posterior infraspinatus and supraspinatus
flap.
Preserve the "Comma" During a Repair Involving the
Subscapularis
Lo and Burkhart reported on the utility of the comma sign, which is a
comma-shaped arc of tissue located at the superolateral border of the
subscapularis, delineating the retracted edge of the
subscapularis6
(Fig. 5, A). They also
suggested that the comma is actually the remnant of the medial sling of the
biceps, which is composed of fibers of the medial head of the coracohumeral
ligament as well as a portion of the superior glenohumeral ligament. We
reported that the supraspinatus has a long intramuscular tendinous portion
located in the anterior half of the muscle, which was found to insert into the
most superior area of the lesser tuberosity in 21% of our specimens
(Fig. 5, B). We
believe that the comma represents this tendinous portion of the supraspinatus,
which connects the supraspinatus and the subscapularis. Therefore, when we
repair the subscapularis, it is very important to preserve this connecting
tissue to avoid postoperative structural failure as well as to restore the
function of the supraspinatus.
Rotator Interval Slide May Not Be a Preferable Procedure
The interval slide, either anteriorly or posteriorly, has been reported to
be a very effective procedure for mobilization of retracted massive rotator
cuff
tears7,8.
However, as we demonstrated in our anatomical study, the distal end of the
infraspinatus tendon courses anterolaterally and inserts into the
anterolateral portion of the superior facet. Further, some of the tendinous
fibers of the supraspinatus run across the bicipital groove and insert into
the lesser tuberosity. We believe that these structures work as a horizontal
link of each rotator cuff tendon, especially in large retracted tears.
Therefore, it is very important to preserve these structural interconnections
in order to avoid failures after repair.
CRITICAL CONCEPTSINDICATIONS:This procedure is applicable for every reparable rotator cuff tear.CONTRAINDICATIONS:There is no specific contraindication to this procedure if the tear is
reparable.PITFALLS:Margin convergence repair is not the preferred method for repairing
u-shaped rotator cuff tears because most u-shaped types of tears are chronic
and represent an advanced stage of the L-shaped tear. Surgeons should evaluate
the mobility of the posterior leaf of the tear before applying the margin
convergence technique.The rotator interval slide as a method to increase mobility in large
retracted tears is not preferred because the tendinous fibers intermingle with
each other and work as a horizontal link at the distal end of the rotator cuff
tear. If surgeons violate this structure, the risk of postoperative failure
may be increased.AUTHOR UPDATE:Through our clinical experience, we believe that, normally, the posterior
leaf of the torn rotator cuff is more mobile compared with the anterior or
central leaf. Furthermore, we have wondered why the integrity of the repair is
relatively poor after the use of the margin convergence suture technique and
the rotator interval slide in larger tears. Therefore, we are very reluctant
to use the margin convergence technique for large u-shaped tears or to use the
rotator interval slide as a mobilization procedure for large retracted
tears.
CRITICAL CONCEPTS
INDICATIONS:
This procedure is applicable for every reparable rotator cuff tear.
CONTRAINDICATIONS:
There is no specific contraindication to this procedure if the tear is
reparable.
PITFALLS:
Margin convergence repair is not the preferred method for repairing
u-shaped rotator cuff tears because most u-shaped types of tears are chronic
and represent an advanced stage of the L-shaped tear. Surgeons should evaluate
the mobility of the posterior leaf of the tear before applying the margin
convergence technique.
The rotator interval slide as a method to increase mobility in large
retracted tears is not preferred because the tendinous fibers intermingle with
each other and work as a horizontal link at the distal end of the rotator cuff
tear. If surgeons violate this structure, the risk of postoperative failure
may be increased.
AUTHOR UPDATE:
Through our clinical experience, we believe that, normally, the posterior
leaf of the torn rotator cuff is more mobile compared with the anterior or
central leaf. Furthermore, we have wondered why the integrity of the repair is
relatively poor after the use of the margin convergence suture technique and
the rotator interval slide in larger tears. Therefore, we are very reluctant
to use the margin convergence technique for large u-shaped tears or to use the
rotator interval slide as a mobilization procedure for large retracted
tears.