Introduction and Index

The decade of the 1980s has seen a spectacu­lar growth in the area of shoulder arthroscopy and there is no doubt that this trend will continue into the next decade. The reason for this parallels the growth of knee arthroscopy during the late 1960s, the decade of the 1970s and the early part of the 1980s. The initial reason that shoulder arthroscopy took off was that it revolutionized the diagnosis of shoulder disorders, previously a realm that could only be mastered by the elite few who had made shoulder surgery their superspecialty. One such expert was Cyriax who encapsulated the attitude of most physicians thus: 'Many doctors regard disorders of the shoulder as uninterest­ing, undiagnosable, and incurable, but tending to recover in the end. Nothing could be further from the truth.' The arthroscope gives the surgeon an extremely powerful tool which not only assists in diagnosis, but by a process of feedback hones the surgeon's own clinical diagnostic acumen, giving an ability to diagnose shoulder disorders more accurately than the superspecialists ever could from out­side the joint.

This book aims to open up this inner world of the shoulder joint and to stimulate interest in conditions around the shoulder. The book is aimed both at surgeons in training and also those experienced surgeons who are either shoulder surgeons who would like to be able to arthroscope the shoulder, or experienced arthroscopists who would like to develop a special interest in the shoulder.

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Arthroscopic surgery

During the latter half of the 1980s it became rapidly apparent that arthroscopy could not only be used as a diagnostic aid around the shoulder, but that it could be used therapeuti­cally.

Immediately a philosophical enigma arose, namely that if arthroscopic surgery was more difficult and less successful than open surgery, then how could it be justified? Avoidance of scar tissue and speed of recovery seemed to be given more emphasis than the efficacy of treatment and the long-term outcome. Added to this was the problem that patients started to vote with their feet, for they had seen how successful minimally invasive surgery had been in the knee, and wanted their shoulder surgery performed by what the media labelled 'painless, bloodless surgery'.

We have subdivided the plethora of arthro­scopic surgical procedures into five gener­ations of increasing complexity (see page 125). Generally the earlier generations of surgery are technically easier and the results are better. Removal of loose bodies and trimming of labral tears are in generation one. Both of these procedures are relatively easy to carry out and can give significant benefit to the patient, with minimal risk of morbidity.

The best of the second generation proce­dures is arthroscopic subacromial decom­pression (ASD) (Chapter 8). The medium-term results of this type of surgery in experienced hands is excellent and its popularity will increase in the next five years. However, it is technically difficult with a long learning curve.

The third and fourth generations of arthrosco­pic surgery are forms of anterior reconstruction and complex reconstruction of traumatic insta­bilities (Chapter 9). The five-year results from the pioneering centres are just becoming avail­able and these show 80-90 per cent short-term success rates4. Since these results are from the best centres, by the most skilled surgeons using the most up-to-date equipment,  in a
concentrated practice, then it is unlikely that the occasional arthroscopic shoulder surgeon will be able to achieve anything like such good results. This should be compared with the 90-95 per cent long-term success rates of open repair techniques such as the Bankart repair, and the Magnusson Stack procedure.

Arthroscopic repair, however, has a shorter learning curve than ASD. The arthroscopic views far exceed the view at open surgery and, in many ways, the procedure is 'easier' than the open procedure, which is technically deman­ding. This is the area of surgery of most rap'd change and evolution and it would be wise for the inexperienced to avoid these procedures until further data is recovered from prospective controlled studies. Whether this advice can hold back the tide of patients who will demand this type of surgery, history alone can tell.

The final and fifth generation of arthroscopic surgery includes rotator cuff repair. There is a place for the arthroscopic repair of small rotator cuff tears at present. This can be carried out either with small arthroscopic suturing instru­ments under vision, or by using arthroscopic staples which are retrieved arthroscopically at six weeks, so as not to cause any damage to the undersurface of the acromion.

Arthroscopic debridement for massive rota­tor cuff tears is stated to relieve pain, although of course it cannot increase shoulder function. Acceptable results are not presently reproduci­ble, and again this type of surgery should only be performed as part of a prospective control­led series, the patient having undergone informed consent as to the unpredictable nature of the results.

It has to be said that there is increasing concern expressed by all shoulder surgeons about the insertion of metal around the shoulder joint. Metal implants of all types (staples and screws) are known to move frequently from their initial position if placed around the shoulder. Presumably this occurs because of the shoul­der's large range of motion and the excessive forces which will occur as a consequence on these metal implants. The shoulder also seems to attract metal implants, and once metal enters the shoulder joint it can lead to rapid and devastating loss of the articular surface. In order to circumvent this problem, biodegrad­able staples are currently being tested.

Naturally, arthroscopic surgery should not be attempted without adequate training. Hopefully this and other books will be a good starting point for surgeons in training, or for surgeons who want to develop the techniques of diagnostic shoulder arthroscopy. The next stage is to attend a shoulder arthroscopy course and then to work with an experienced shoulder arthroscopic surgeon. Only after per­forming some 50 diagnostic arthroscopies should the aspiring shoulder arthroscopist attempt the more simple 'first generation' tech­niques. Second generation surgery should only be undertaken after 100 diagnostic arthrosco­pies have been performed, and presently third generation surgery and upwards should only be performed by skilled shoulder arthroscop-ists as part of prospective controlled studies.

Finally, it must be remembered, that arthro­scopy alone may help the patient but it is not a cure. Most cures for the shoulder still require the skills of open shoulder surgery and it must be stressed that shoulder arthroscopy should not be used unless the surgeon has, or develops, the skills of open shoulder surgery. Over the last few years, minimally invasive surgery of the shoulder using the arthroscope has begun to show promise. Just as arthrosco­pic meniscectomy popularized the use of the arthroscope in the knee, this ability to treat shoulder disorders arthroscopically may well drive shoulder arthroscopy in the coming years. For this reason, we have included three chap­ters on arthroscopic surgery of the shoulder, while realizing that this is such a rapidly changing field that methods outlined in this book will inevitably be replaced by even better techniques in years to come.

Indications

Initially  shoulder  arthroscopy was  used  for diagnostic purposes alone. Such studies soon showed that clinical diagnosis was often incor­rect and that shoulder arthroscopy could diagnose many conditions accurately. Cofield1 reviewed 74 diagnostic arthroscopies and found that in 32 per cent, arthroscopy was important in making, confirming or modifying the diagnosis or in altering the course of treatment. In a further 45 per cent, it was optional and in only 23 per cent was it unneces­sary. In trying to establish which modality gave a firm diagnosis, Cofield found that arthroscopy was twice as accurate as a combination of history, examination and routine radiographs.

The author's experience with the first 50 shoulder arthroscopies2 was similar. In 27 cases out of 50, the diagnosis was changed or refined. In particular, dual or even triple pathol­ogy was found, and unexpected rotator cuff tears and loose bodies were not uncommon findings. Such a high diagnostic score has brought some shoulder surgeons to contem­plate the need for shoulder arthroscopy in the majority of patients presenting with significant shoulder disorders. Logistically of course, this is not possible and so we have to consider which particular groups of patient can benefit most by diagnostic shoulder arthroscopy. There are four groups in whom shoulder arthroscopy is most helpful:

Patients aged 18-35, with recurrent shoul­der discomfort following trauma: It is becoming clearer that pain following trauma to the shoul­der in young people is often due to instability. Rowe and Zarins' classic paper3 describing transient subluxation and the dead arm syn­drome initially brought this to the attention of the general orthopaedist, but this can be a difficult diagnosis to confirm.

Shoulder arthroscopy can be useful in this group, particularly if a Bankart lesion is present.

Damage to the inferior glenohumeral ligament, with or without a Bankart lesion, and damage to the middle glenohumeral ligaments are further pointers. There may be a Hill-Sachs lesion on the humeral head, some of which may be cartilaginous only, and therefore not show up on a Stryker Notch (West Point) radiograph. A loose body in the joint is most commonly associated with a Hill-Sachs lesion following an episode of dislocation, and damage to the anterior glenoid rim may be a further indication of recurrent subluxation.

Just as important as shoulder arthroscopy in this group is the examination under anaesthetic (EUA). This is a load and shift test and is described on page 36. To many surgeons, the EUA is actually more important than arthro­scopy in recurrent subluxation. Certainly it should never be omitted. EUA should be performed before the arthroscopy, as it is easier in a fresh joint, before distension has been carried out. The problem with performing the EUA first is that it may cause intra-articular bleeding, but this can be controlled by adequ­ate lavage (Figure A).

Patients over 35, with chronic subacromial impingement: To the shoulder surgeon, the painful arc is one of the most common presen­tations. Typically, patients complain of a painful arc of movement in the range of 70 to 120 degrees of elevation. If this does not settle within six months, with either physiotherapy or local installation of one injection of steroid, then arthroscopy is indicated (Chapter 8).

In particular, the surgeon will be looking for evidence of a rotator cuff tear (Figures B and C). Arthroscopically, the insertion of both supraspinatus (Figure D) and infraspinatus can be seen at the synovial reflection onto the humeral neck. Supraspinatus inserts onto the greater tuberosity behind the tunnel of the long head of biceps, the tendon being used as a landmark. Infraspinatus inserts onto the bare area of the posterior humeral head (Figure E).

The arthroscopist has the advantage over the radiologist in that the superior surface of the rotator cuff can be visualized as well, by performing a bursal endoscopy. The classic impingement lesion, an area of 'hairy degener­ation' of the superior surface of the rotator cuff, may be seen (Figure F), or there may be a partial tear or ruffling up of the cuff. Any abnormality of the cuff can be probed, giving further tactile information. Partial thickness tears, which would not be visualized arthro-graphically, or areas of inflammation can be seen (Figure G) and probed. Tendinitis of the long head of biceps (Figure H) may be a marker of impingement and cuff tear.

Fig A: Bleeding from a Bankart lesion following examination under anaesthetic can be controlled by lavage.

Figure B: A full thickness rotator cuff tear above the humeral head.

Figure C: The rolled mature edge of a rotator cuff tear next to the long head of the biceps tendon

Figure D: The insertion of supraspinatus next to the long head of biceps

Figure E: The bare area of the humeral head

Figure F: The impingement lesion  a hairy degeneration of the superior surface of the rotator cuff

Figure G: Synovitis of the superior half of the biceps tendon.

Figure H: Repairs of the rotator cuff can be difficult to see (and therefore to photograph). Seen here is an Ethibond suture of a rotator cuff repair just above the long head of the biceps tendon.

Atypical shoulder pain: In the past, this had to be managed empirically, for a definite diagnosis could not be made. Under these circumstances, arthroscopy can be of great value. In particular, the following diagnoses can often be missed clinically:

• glenoid labral tears, which may give inter­mittent shoulder pain or unpredictable lock­ing or catching of the joint
• instability with no good history of initial dislocation
• loose bodies
• early degenerative arthritis.

Failed previous shoulder surgery: With patients whose symptoms persist after open shoulder surgery, the first factor to be consi­dered is whether the original diagnosis was correct. As discussed, Cofield's work1 makes clear that clinical diagnosis is an unpredictable art. For this reason, shoulder arthroscopy can be useful. Diagnosis may be changed or confirmed, or a second pathology revealed.

However, assessment of the rotator cuff can be very difficult after previous open surgery. For example, the arthroscopist may be misled when thin scar tissue gives the impression that the cuff is intact, although mechanically the cuff behaves as if it were disrupted. Cuff function is dependent on a good mechanical reconstruc­tion with full thickness cuff material. Furth­ermore, adhesions may develop in the sub­acromial bursa, making visualization of the cuff repair difficult (Figure I).

Other areas where symptoms may remain following open surgery are unrecognized loose bodies, labral tears and early degenerative arthritis

Index: Extracapsular Anatomy for Shoulder Arthroscopy Assessment of the shoulder Imaging the shoulder Clinical procedure Normal arthroscopic examination Abnormal findings Arthroscopic surgery Arthroscopic Subacromial Decompression Arthroscopic Management of Traumatic Shoulder Dislocations