Arthroscopic Rotator Cuff Findings
Alessandro Castagna, MD
Marco Conti, MD
Milan, Italy


Introduction

The understanding and treatment of the pathology of the rotator cuff muscle-tendon complex is probably still the most stimulating challenge for the shoulder surgeon. Anatomy, biomechanics, presence of multiple layers of tissues, limited subacromial space make often difficult a precise assessment of the cuff disorders and therefore a proper repair.

History, clinical examination and imaging will help the surgeon for an exact diagnosis. Imaging of the rotator cuff tears improved a lot in the last years. MRI, especially with gadolinium enhancement, allows a rather precise pre-operative assessment. But other basic tests like x-rays (AP, Axillary and Arch-View) should never be skipped. Finally the surgeon should always compare the radiologist report with the history and clinical exam. This procedure allows avoiding over- or under- diagnosis of rotator cuff disorders.

Arthroscopy demonstrated a great role in the assessment of rotator cuff disorders and in the operative decision making.


General Technique of arthroscopic RC assessment

Anatomically five tendons belonging to muscles originating from the scapula form the RC.   Viewing from anterior to posterior they are:

  • Subscapularis
  • Supraspinatus
  • Intrarticular long head of the biceps
  • Infraspinatus
  • Teres minor

Many authors consider the intra-articular part of the long head of the biceps functionally a part of the RC.

The arthroscopic evaluation of RC must be done both from the articular side and the bursal side of the tendons, viewing through the standard posterior and anterior portals.  It may help also the use of the lateral portal. The assessment procedure should be performed following a systematic and complete protocol of review of the shoulder anatomy (1).  Use of a pump for distension and a controlled hypotension is very helpful (almost necessary) for a better view in the subacromial space.


Intra-articular rotator cuff evaluation

Posterior portal view (moving the scope from anterior to posterior):

  • superior margin of the subscapularis lying anteriorly between the glenoid and the humeral head
  • supraspinatus lying over the biceps tendon
  • intra-articular part of the long head of the biceps and its anchor on the glenoid
  • anterior aspect of the infraspinatus at his insertion near the bare area of the humeral head

Anterior portal view (moving the scope from posterior to anterior):

  • infraspinatus and teres minor tendons
  • supraspinatus tendon
  • long head of the biceps
  • subscapularis tendon up to its insertion on the lesser tuberosity (sliding up to this point is very critical since the scope can easily be pulled out of the joint. This manoeuvre must be performed smoothly but is very important to check the subscapularis tendon insertion to the humeral head and have a look of its relationship with the biceps entering into the groove)


Bursal side rotator cuff evaluation

Bursal tissue covering the cuff tendon may confuse the view. For this reason bursectomy and removal of frayed tissues is requested to clean the view when a rotator cuff lesion must be clearly identified.

The subacromial space assessment must be performed viewing from anterior, posterior and lateral portals.

Posterior portal view (moving the scope from anterior to posterior and then lateral to medial):
Note: the scope must be introduced forward since the bursa is an anterior structure and the posterior bursa may hide the view

  • supraspinatus tendon
  • infraspinatus tendon
  • subdeltoid shelf
  • greater tuberosity
  • musculo-tendinous junction of the cuff

Anterior portal view (moving the scope from posterior to anterior and then from lateral to medial):

  • posterior bursa ( it is very important to remove it for a clear view in case of a repair)
  • infraspinatus tendon
  • supraspinatus tendon
  • subdeltoid shelf
  • greater tuberosity
  • musculo-tendinous junction of the cuff

Lateral portal view (moving the scope from anterior to posterior):

  • supraspinatus tendon
  • infraspinatus tendon
  • subdeltoid shelf
  • greater tuberosity
  • musculo-tendinous junction of the cuff


Classification of rotator cuff tears

Lesions of the rotator cuff may present with different aspects, grades, morphology and severity. Many attempts were made to classify homogeneously the rotator cuff tears but so far no one seems to be perfect (2).

When looking at the cuff tendons it is important to understand:

  • full thickness or partial thickness
  • size of tear
  • number of tendons involved
  • side (articular and /or bursal) and depth of partial thickness
  • retraction of the tendons
  • quality of the tendon
  • shape of the full thickness tear

The use of a common standard evaluation system is important for exchanging information with other surgeons, follow-up and proper decision making. For the experienced arthroscopist it is possible to perform a precise evaluation of the rotator cuff tears. A good system of classification is the one proposed by Snyder which allows a systematic classification of the intraoperative finding (1) (Table 1).    Unfortunately the intratendinous lesions are not visible for the arthroscopist and they represent an important topic for the treatment of the rotator cuff disease as Fukuda demonstrated (3) (Fig. 1).

Table. I

Classification of Rotator Cuff Tears as proposed by Snyder.
It makes possible a standard evaluation for the arthroscopist

 

Tendon(s) involved in tear

  • SS = Supraspinatus tendon
  • IS = Infraspinatus tendon
  • SbS =  Subscapularis tendon
  • RI =  Rotator interval

Location of tear

  • A = Articular surface
  • B = Bursal surface
  • C = Complete tear, connecting A to B

Severity of tear

0 =  Normal cuff, with smooth coverings of synovium and bursa

I = Minimal superficial bursal or synovial irritation or slight capsular fraying in a small localised area; usually < 1cm

II = Actual fraying or failure of some rotator cuff fibers in addition to synovial, bursal or capsular injury; usually < 2 cm

III = More severe rotator cuff injury, including fraying and fragmentation of tendon fibers, often involving the whole surface of a cuff tendon (most often the supraspinatus); usually < 3 cm

IV = Very severe partial rotator cuff tear that usually contains, in addition to fraying and fragmentation of tendon tissue, a sizeable flap tear; usually larger in size than grade I-III and often encompass more than a single tendon

cuff_fig1.gif (10946 bytes)

Fig. 1
Intratendinous partial RCT are not visible to the arthroscopist
and represent a problem both for diagnosis and treatment


Technical pearls

Full thickness and partial thickness

Sometimes is not so easy to understand the severity of a rotator cuff tear. Finding intra-articular erosion in the critical zone is rather common but if we don’t see an obvious communication with the subacromial space we don’t know how important is that erosion. Viewing the bursal side of the same area is very important for an adequate assessment and decision making. For this reason the surgeon should be confident with the use of the "suture marker technique" (2). With a spinal needle an absorbable suture is passed trough the lesion intra-articular. Moving the scope to the subacromial space, the suture will allow the evaluation of the tendon corresponding exactly with the articular lesion. (Fig 2, Fig 3)

cuff_fig2.jpg (13780 bytes)

Fig. 2
Inta-articular view of the suture marker

 

cuff_fig3.jpg (12257 bytes)

Fig. 3
Bursal view of the same suture marker

Retraction, mobility and shape of tear

The retraction of the tear is important for surgical choice. But retraction itself is not enough for a final judgement. Sometimes a tendon retracted beyond the long head of the biceps is still mobile and can be easily brought back to the greater tuberosity.

This can be tested with a grasper inserted in the lateral portal and testing tendon mobility (Fig. 4).

cuff_fig4.jpg (14888 bytes)

Fig. 4
The grasper test to verify the mobility of the RCT

Also the shape of the tear is important. Often large tears (mostly the "V" shaped) can be reduced in size with some side-to side suture. After it they will appear smaller and can be repaired more easily to bone with reduced tension. (Fig 5, Fig. 6). To understand the shape of the tear is important to take a view from different portals

cuff_fig5.jpg (15452 bytes)

Fig. 5
Full thickness RCT

 

cuff_fig6.jpg (14671 bytes)

Fig. 6
Same tear after a side-to-side partial repair: obvious size reduction

Quality of tendon

This is the most difficult evaluation (unless the obvious conditions) especially for partial thickness and / or intratendinous lesions.

To evaluate the tendon that appear inserted to the bone and with no evident erosion in the articular face, but looks not good, I try to understand the situation with a test that I called the "flag test".

While watching carefully with the scope I turn off and on the pump. A good tendon responds smoothly to the reduction of intrarticular shape. A bad tendon reacts quickly moving up and down like a flag in the wind. If it happens, it is my feeling that the tendon may have an intratendinous degeneration and may need a repair after inducing a full thickness tear.

Long head of the biceps and subscapularis

Tear of the subscapularis tendon is rare but it is significant for the shoulder function and frequently related to LHB lesion (4).

Some aspects of these lesions may be subtile and must be carefully evaluated.

From the posterior portal the superior margin of the subscapularis tendon can be seen and its angle of incidence with the LHB observed. When the two tendons look in touch, or overlapping at the apex of the triangle, a medial luxation of the LHB must be suspected.

Looking from the anterior portal the subscapularis tendon can be followed up to the lesser tuberosity (though it is a manoeuvre that must be performed carefully since it’s easy to pull out the scope from the joint) continuing to the LHB at the entrance of the groove.

From the posterior portal it is useful to apply a little traction with a probe on the LHB in order to verify the quality of the tendon at the entrance of the groove. A good looking intra-articular biceps tendon may become a frayed (and painful) tendon into the groove.

Sometimes a medial dislocation of the LHB may cut the upper part of the subscapularis tendon that will appear like a meniscal bucket-handle tear inside the joint, confusing the surgeon (Fig 7).

cuff_fig7.jpg (14545 bytes)

Fig. 7
Torn subscapularis tendon inside the joint

Impingement

True impingement as described by Neer (5) can be recognised watching at the inferior aspect of coraco-acromial ligament and anterior acromion. When they look frayed a mechanical impingement with the underlying bursa and cuff (frayed too) must be considered. When they look smooth probably the cause of pain should be searched somewhere else.

 

References

1) Snyder S.J., Shoulder arthroscopy, McGraw-Hill,1993

2) Ciepiela MD, Burkhead WZ. Classification of rotator cuff tears, in Burkhead WZ, ed. Rotator cuff disorders, Baltimora:Williams & Wilkins, 1996:100 -107

3) Fukuda H, Craig EV, Yamanaka K, Partial thickness cuff tears, in Burkhead WZ, ed. Rotator cuff disorders, Baltimora: Williams & Wilkins, 1996:174-181

4) Habermeyer P, Walch G, The biceps tendon and rotator cuff disease, in Burkhead WZ, ed. Rotator cuff disorders, Baltimora: Williams & Wilkins, 1996:142-159

5) Neer CS. Impingement lesions. Clin. Orthop.1983;173:70






Last updated December 10, 1999 by webguru@shoulder.com
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