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.