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Arthroscopy of the shoulder: diagnostic and surgical
9 Arthroscopy of the shoulder: diagnostic and surgical CHRISTOPHER
R. C O N S T A N T
Arthroscopy and arthroscopic surgery of the knee have dramatically changed knee surgery as we know it today. Dandy (1981) has described many procedures which can be undertaken either partially or completely arthroscopically. The same cannot yet be said for the shoulder joint, in which diagnostic and surgical arthroscopy still play a minor role in the overall treatment of shoulder conditions. This is likely to remain so for the foreseeable future. A R T H R O S C O P I C A N A T O M Y AND COMPLICATIONS
The relevant anatomy of the shoulder joint in relation to arthroscopy is (1) the presence of a thick and extensive cuff of musculature and tendons around the shoulder, extending anteriorly, superiorly and posteriorly, and (2) the proximity of major vessels and nerves in the brachial plexus. The anatomy of the axillary artery complex (Figure 1) must always be kept in mind when considering portals and instrument insertion. The anatomy of the nerve to infraspinatus, suprascapular nerves and vessels, and the axillary nerve, must all be carefully borne in mind, as they are never more than a few millimetres away from the instruments being used. The deep position of the shoulder joint in relation to the rotator cuff, the deltoid and the trapezius muscles make it necessary to perforate several muscle layers in order to enter the joint; this may frequently result in significant bleeding from the portals. Postoperative intramuscular collections of blood, as well as collections of blood in the subcutaneous tissues, are not uncommon but fortunately do not present a major problem. They are, however, a potential risk. Furthermore, as a tourniquet cannot be applied to the shoulder, it is necessary to use high-pressure fluid distension, with or without adrenaline, to control bleeding within the joint. This allows satisfactory visualization but, in turn, may result in the accumulation of anything from minor to massive amounts of fluid in the pericapsular tissues (Figure 2). Neurovascular compression caused by this fluid collection can occasionally occur. Needless to say, penetrating injuries of the neighbouring nerves and vessels may have catastrophic consequences. Baillibre's ClinicalRheumatology--Vol. 3, No. 3, December1989
583
584
c . R . CONSTANT
Figure 1. Relationship of the neurovascular bundle to the shoulder.
Figure 2. Fluid collection around posterior portal during shoulder arthroscopy.
ARTHROSCOPY
585
INDICATIONS FOR S H O U L D E R A R T H R O S C O P Y
Diagnostic indications for shoulder arthroscopy include, instability, subacromial impingement, rotator cuff tears, shoulder arthritides, synovitis and intra-articular loose bodies. Diagnostic arthroscopy forms part of the preoperative 'work up' in the conditions described, frequently adding important information to that already obtained by clinical history and examination, radiological investi-
Figure 3. Magnetic resonance image scan of the shoulder.
586
c.R. CONSTANT
gation, computerized tomographic scans and magnetic resonance imaging (Figure 3). The direct visualization of structures within the shoulder joint frequently gives information far superior to that obtained by other diagnostic procedures. DIAGNOSTIC ARTHROSCOPY IN SPECIFIC CONDITIONS Shoulder instability Arthroscopy of the shoulder in this condition can he used (1) to assess the direction of instability, (2) to document the lesions requiring treatment, and (3) to establish their severity. It is particularly important where the direction of instability has not been seen radiologically, as occurs when patients arrive at hospital with a history of shoulder dislocation and subsequent spontaneous reduction. The direction of instability in such cases may be obscure and routine investigations may not be specifically helpful in determining the direction. Furthermore, in some individuals it is now recognized that multidirectional instability is a feature of their condition, and reliance upon a series of X-rays, which demonstrate uni-directional instability, may result in a significant flaw in their management. The patient with multi-directional instability does not significantly benefit from stabilization of the anterior, posterior or inferior areas without appropriate management of the instabilities in other directions. Failure following surgery may result from the preoperative failure to recognize the correct direction or multiplicity of directions in which instability is occurring. In such instances, it is not uncommon for an anterior stabilization to aggravate the posterior or inferior instability. Nor is it uncommon for patients with multi-directional instability to be treated by an anterior, or perhaps posterior stabilization, following which further instability in the opposite direction to which the repair has been undertaken occurs at increasingly frequent intervals. Subluxations, clicks and clunks in the shoulder These are frequently seen in patients in whom clinical examination and radiological assessment do not provide the answer as to the source of the problem. In this situation, arthroscopy may well demonstrate an unstable biceps tendon, a detached, or bucket-handle lesion of the glenoid labrum, or a loose body. The conditions are frequently difficult to assess radiologically; arthroscopy often provides the only reliable way to diagnose such lesions. Rotator cuff tears A n o t h e r important condition in which arthroscopy may be useful is in the assessment of rotator cuff tears. A full thickness rotator cuff tear is easily seen on an arthrogram (Figure 4); however, a partial thickness tear on either the upper or lower surface of the cuff, or indeed thickening in association with an intramural tear, may be difficult to diagnose on clinical or radiological
ARTHROSCOPY
587
Figure 4. Arthrogram of shoulder showing full thickness tear in the rotator cuff.
grounds, although a clinical suspicion of such lesions may be indicated by weakness on repetitive testing of abduction against resistance. The use of the arthroscope to see the subacromial surface as well as the glenohumeral surface of the rotator cuff makes the diagnosis of such lesions possible and easy. A c o m m o n cause for rotator cuffsurgery to failis poor delineation of the tear, and consequent poor repair. Accurate identification of the lesions at arthroscopy make this problem a thing of the past. A weakness of the rotator interval (between the subscapularis and supraspinatus muscles) is often only vaguely implied on an arthrogram. Arthroscopy readily demonstrates this lesion. The method used for repair of a rotator cuff depends on its size, as well as on the extent of retraction of the components of the tear. It is sometimes necessary to consider the use of such equipment as cantilever braces (Figure 5) or abduction wedges. It is usually desirable to know this in advance so that postoperative rehabilitation can be discussed and planned with the patient. Arthroscopy allows accurate identification of the size of the tear and, in turn, the planning of appropriate operative techniques, as well as postoperative rehabilitation which can then be discussed with the patient prior to undertaking such major surgery. While it is now possible, although difficult, to measure the size of a rotator cuff tear using ultrasound or double-contrast computerized axial arthrotomography, arthroscopy allows a direct visualization of the tear and direct, accurate assessment of its size.
588
C . R . CONSTANT
Figure 5. Cantilever brace. Subacromial impingement and rotator cuff tendinitis
In patients who demonstrate persistent and resistant subacromial impingement and rotator cuff tendinitis, in whom an injection test has proved positive and in whom arthrography shows no rotator cuff tear, the use of an arthroscope to undertake bursoscopy (inspection of the subacromial bursa through the arthroscope) can usually provide valuable information about the state of the subacromial surface, the coracoacromial ligament and the upper surface of the cuff. A subacromial osteophyte or roughening can easily be seen with the arthroscope, whereas X-ray and arthrogram appearances are frequently normal. A supraspinatus outlet radiograph (Figure 6), using a lateral projection of the scapula, is a useful projection for seeing the subacromial osteophytes. As will be mentioned later, the use of an arthroscopically-inserted power shaver to undertake an acromioplasty is now possible. The arthritides
Many studies have shown the value of hemi and total shoulder arthroplasty in the treatment of rheumatoid and osteoarthritis, as well as in those patients with aseptic necrosis and following four-part fractures and fracture dislocations of the shoulder. The results of such hemi or total shoulder arthroplasties depend on a combination of factors, including correct patient selection for likely patient compliance with postoperative rehabilitation, surgical technique (in particular, reconstruction of soft tissues) and the patient's motivation to get better, as described by Constant and Welsh (1985).
ARTHROSCOPY
589
Figure 6. Lateral projection of the scapula showing irregularity of the supraspinatus outlet.
Patient selection on the basis of the diagnosis is generally not a problem, and it is usually quite clear on clinical and radiological grounds whether a shoulder replacement would be an appropriate procedure to undertake. What is frequently more difficult to assess is the patient's motivation to undergo the extensive and often long rehabilitation following such surgery. Preoperative assessment by the physiotherapist is now a routine in those cases where motivation is not clearly defined. If compliance with physiotherapy is unlikely to be forthcoming, then major shoulder surgery in the form of arthroplasty is probably better withheld in favour of other methods of treatment for pain relief. Occasionally, shoulder replacement for pure pain relief and nothing more may be considered, but it is important for both patient and surgeon to be aware of this prior to the procedure being undertaken. In those in whom it is unclear whether or not they will comply with physiotherapy postoperatively, an arthroscopy can provide a valuable indication. As well as providing important information regarding the joint surfaces and the condition of the soft tissue, in particular the cuff, an
590
c.R. CONSTANT
arthroscopy allows the doctor to assess patient response to physiotherapy after such a relatively minor procedure. It is the author's experience that patients who do not comply with the relatively simple rehabilitation programme following an arthroscopy of the shoulder in the presence of arthritis, will not undertake the more major rehabilitation requested following major shoulder surgery in the form of arthroplasty. OPERATIVE P R O C E D U R E
The arthroscopic examination is undertaken with the patient under full general anaesthetic; the arm is supported at 45-60 ~ of abduction with slight forward flexion of, perhaps, 30 ~. This position is held either by an assistant or by single or double traction units. The use of a second traction device lifting the arm away from the side helps to achieve better visualization of the joint. The traction weight applied to the arm should be carefully monitored as a brachial plexus palsy may result if excessive traction is applied. A posterior portal is used for the insertion of the scope; a standard arthroscope (30 ~ 5 mm) is used by the author. Prior to insertion of the scope, the joint is distended with saline. A detailed and systematic examination of the shoulder joint, beginning with the biceps tendon and proceeding to the glenoid, surrounding labrum, joint surfaces, soft tissues including glenohumeral ligaments and inferior recess, and finally the posterior aspect of the shoulder joint, is undertaken. Examination of the under-surface of the rotator cuff is followed by insertion of the scope into the subacromial bursa through a rotator cuff tear, if this is present, or through a separate route if the rotator cuff is intact. Assessment of the under-surface of the acromion and the inferior surface of the acromioclavicular joint, as well as the superior surface of the cuff, is made. By rotating the arm in the position of traction, it is possible to visualize the entire surface of the humeral head. It should be noted that there is normally a small bare area in the posterior part of the anatomical neck of the humerus; this should not be confused with a significant Hill-Sachs deformity (depressed crush fracture of the posterior aspect of the anatomical neck associated with anterior dislocation of the shoulder). Instrumentation through a superior portal, between the outer end of the clavicle and the medial part of the acromion, or, more usually, through an anterior portal, inserting the instrument between the middle glenohumeral ligament and the biceps tendon, allows probing and instrumentation within the shoulder joint. The use of hydrodistension, with or without adrenaline, allows adequate haemostasis within the joint while arthroscopy and arthroscopic surgery are being undertaken. The use of an irrigation/drainage cannula with a tap is useful, though not essential. Joint laxity can also be assessed using the probe. The rotator interval is easily seen and can be probed, so that weaknesses in this area, frequently not seen on an arthrogram, can be detected without difficulty. Arthroscopic anatomy of the shoulder and lesions seen arthroscopically were well described by Detrisac and Johnson (1986).
ARTHROSCOPY
591
ARTHROSCOPIC SURGERY OF THE SHOULDER
Arthroscopic surgery of the shoulder should only be considered by those who are fully competent in the art of diagnostic arthroscopy and who are totally familiar with the arthroscopic anatomy of the shoulder, triangulation techniques and the significance of the intra-articular pathology seen. The following arthroscopic surgical techniques may be undertaken in the shoulder joint with varying degrees of success, depending on the skill of the operator. Synovectomy, synovial biopsy and removal of loose bodies
This involves the use of two portals and is probably the simplest of all arthroscopic procedures undertaken in the shoulder. Removal of loose bodies is not as difficult as in the knee because the recesses in which they usually settle are more accessible in the shoulder. Division of the glenohumeral ligaments
Tight glenohumeral ligaments, in particular the middle glenohumeral ligament, are seen in patients with adhesive capsulitis. Following gentle manipulation and hydrostatic distension, division of these ligaments using a retractable arthroscopic knife usually provides significant improvement in passive range of movement under anaesthesia. The division of such ligaments should not extend beyond the shoulder capsule. Fixation of a Bankart labral detachment
Screw, staple or suture fixation of a Bankart labral detachment can be undertaken arthroscopically, although the results have not yet been satisfactorily evaluated in the longer term. The procedures involved in Bankart fixation are difficult and frequently time consuming. The operator should be aware of the need sometimes to revert to an open operation to succeed in stabilizing the joint if arthroscopic methods fail. Subacromial decompression and acromioplasty
Using bursoscopy, either through a rotator cuff tear or by direct insertion of the scope into the bursa, in combination with a power shaver, the subacromial surface may be shaved down to provide a satisfactory acromioplasty/ decompression of the rotator cuff. Bleeding from the marginal artery on the front of the acromion may present a significant problem. Extension of the acromioplasty for the partial excision of the coracoacromial ligament can also be undertaken. An associated rotator cufftear, if not severely retracted, or an interval rotator cuff weakness can be sutured satisfactorily arthroscopically. This particular procedure requires a great deal of experience to achieve a rotator cuff repair successfully.
592
c.R. CONSXANT
CONCLUSION Shoulder arthroscopy can be considered to be a valuable m e t h o d of investigating problems in specific instances. Surgical arthroscopy of the shoulder has a limited place in the treatment of some shoulder disorders. Neither are particularly easy procedures. Arthroscopic surgery requires a great deal of experience and should not be undertaken until total familiarity with diagnostic arthroscopy has been achieved. Complications, when they occur, can be serious and relate entirely to operator inexperience.
REFERENCES Constant CR & Welsh RP (1985) Shoulder Replacement. Berlin: Springer. Dandy DJ (1981) Arthroscopic Surgery of the Knee. Edinburgh: Churchill Livingstone. Detrisac DA & Johnson LL (1986) Arthroscopic Shoulder Anatomy. New Jersey: Slack.
R. C O N S T A N T
Arthroscopy and arthroscopic surgery of the knee have dramatically changed knee surgery as we know it today. Dandy (1981) has described many procedures which can be undertaken either partially or completely arthroscopically. The same cannot yet be said for the shoulder joint, in which diagnostic and surgical arthroscopy still play a minor role in the overall treatment of shoulder conditions. This is likely to remain so for the foreseeable future. A R T H R O S C O P I C A N A T O M Y AND COMPLICATIONS
The relevant anatomy of the shoulder joint in relation to arthroscopy is (1) the presence of a thick and extensive cuff of musculature and tendons around the shoulder, extending anteriorly, superiorly and posteriorly, and (2) the proximity of major vessels and nerves in the brachial plexus. The anatomy of the axillary artery complex (Figure 1) must always be kept in mind when considering portals and instrument insertion. The anatomy of the nerve to infraspinatus, suprascapular nerves and vessels, and the axillary nerve, must all be carefully borne in mind, as they are never more than a few millimetres away from the instruments being used. The deep position of the shoulder joint in relation to the rotator cuff, the deltoid and the trapezius muscles make it necessary to perforate several muscle layers in order to enter the joint; this may frequently result in significant bleeding from the portals. Postoperative intramuscular collections of blood, as well as collections of blood in the subcutaneous tissues, are not uncommon but fortunately do not present a major problem. They are, however, a potential risk. Furthermore, as a tourniquet cannot be applied to the shoulder, it is necessary to use high-pressure fluid distension, with or without adrenaline, to control bleeding within the joint. This allows satisfactory visualization but, in turn, may result in the accumulation of anything from minor to massive amounts of fluid in the pericapsular tissues (Figure 2). Neurovascular compression caused by this fluid collection can occasionally occur. Needless to say, penetrating injuries of the neighbouring nerves and vessels may have catastrophic consequences. Baillibre's ClinicalRheumatology--Vol. 3, No. 3, December1989
583
584
c . R . CONSTANT
Figure 1. Relationship of the neurovascular bundle to the shoulder.
Figure 2. Fluid collection around posterior portal during shoulder arthroscopy.
ARTHROSCOPY
585
INDICATIONS FOR S H O U L D E R A R T H R O S C O P Y
Diagnostic indications for shoulder arthroscopy include, instability, subacromial impingement, rotator cuff tears, shoulder arthritides, synovitis and intra-articular loose bodies. Diagnostic arthroscopy forms part of the preoperative 'work up' in the conditions described, frequently adding important information to that already obtained by clinical history and examination, radiological investi-
Figure 3. Magnetic resonance image scan of the shoulder.
586
c.R. CONSTANT
gation, computerized tomographic scans and magnetic resonance imaging (Figure 3). The direct visualization of structures within the shoulder joint frequently gives information far superior to that obtained by other diagnostic procedures. DIAGNOSTIC ARTHROSCOPY IN SPECIFIC CONDITIONS Shoulder instability Arthroscopy of the shoulder in this condition can he used (1) to assess the direction of instability, (2) to document the lesions requiring treatment, and (3) to establish their severity. It is particularly important where the direction of instability has not been seen radiologically, as occurs when patients arrive at hospital with a history of shoulder dislocation and subsequent spontaneous reduction. The direction of instability in such cases may be obscure and routine investigations may not be specifically helpful in determining the direction. Furthermore, in some individuals it is now recognized that multidirectional instability is a feature of their condition, and reliance upon a series of X-rays, which demonstrate uni-directional instability, may result in a significant flaw in their management. The patient with multi-directional instability does not significantly benefit from stabilization of the anterior, posterior or inferior areas without appropriate management of the instabilities in other directions. Failure following surgery may result from the preoperative failure to recognize the correct direction or multiplicity of directions in which instability is occurring. In such instances, it is not uncommon for an anterior stabilization to aggravate the posterior or inferior instability. Nor is it uncommon for patients with multi-directional instability to be treated by an anterior, or perhaps posterior stabilization, following which further instability in the opposite direction to which the repair has been undertaken occurs at increasingly frequent intervals. Subluxations, clicks and clunks in the shoulder These are frequently seen in patients in whom clinical examination and radiological assessment do not provide the answer as to the source of the problem. In this situation, arthroscopy may well demonstrate an unstable biceps tendon, a detached, or bucket-handle lesion of the glenoid labrum, or a loose body. The conditions are frequently difficult to assess radiologically; arthroscopy often provides the only reliable way to diagnose such lesions. Rotator cuff tears A n o t h e r important condition in which arthroscopy may be useful is in the assessment of rotator cuff tears. A full thickness rotator cuff tear is easily seen on an arthrogram (Figure 4); however, a partial thickness tear on either the upper or lower surface of the cuff, or indeed thickening in association with an intramural tear, may be difficult to diagnose on clinical or radiological
ARTHROSCOPY
587
Figure 4. Arthrogram of shoulder showing full thickness tear in the rotator cuff.
grounds, although a clinical suspicion of such lesions may be indicated by weakness on repetitive testing of abduction against resistance. The use of the arthroscope to see the subacromial surface as well as the glenohumeral surface of the rotator cuff makes the diagnosis of such lesions possible and easy. A c o m m o n cause for rotator cuffsurgery to failis poor delineation of the tear, and consequent poor repair. Accurate identification of the lesions at arthroscopy make this problem a thing of the past. A weakness of the rotator interval (between the subscapularis and supraspinatus muscles) is often only vaguely implied on an arthrogram. Arthroscopy readily demonstrates this lesion. The method used for repair of a rotator cuff depends on its size, as well as on the extent of retraction of the components of the tear. It is sometimes necessary to consider the use of such equipment as cantilever braces (Figure 5) or abduction wedges. It is usually desirable to know this in advance so that postoperative rehabilitation can be discussed and planned with the patient. Arthroscopy allows accurate identification of the size of the tear and, in turn, the planning of appropriate operative techniques, as well as postoperative rehabilitation which can then be discussed with the patient prior to undertaking such major surgery. While it is now possible, although difficult, to measure the size of a rotator cuff tear using ultrasound or double-contrast computerized axial arthrotomography, arthroscopy allows a direct visualization of the tear and direct, accurate assessment of its size.
588
C . R . CONSTANT
Figure 5. Cantilever brace. Subacromial impingement and rotator cuff tendinitis
In patients who demonstrate persistent and resistant subacromial impingement and rotator cuff tendinitis, in whom an injection test has proved positive and in whom arthrography shows no rotator cuff tear, the use of an arthroscope to undertake bursoscopy (inspection of the subacromial bursa through the arthroscope) can usually provide valuable information about the state of the subacromial surface, the coracoacromial ligament and the upper surface of the cuff. A subacromial osteophyte or roughening can easily be seen with the arthroscope, whereas X-ray and arthrogram appearances are frequently normal. A supraspinatus outlet radiograph (Figure 6), using a lateral projection of the scapula, is a useful projection for seeing the subacromial osteophytes. As will be mentioned later, the use of an arthroscopically-inserted power shaver to undertake an acromioplasty is now possible. The arthritides
Many studies have shown the value of hemi and total shoulder arthroplasty in the treatment of rheumatoid and osteoarthritis, as well as in those patients with aseptic necrosis and following four-part fractures and fracture dislocations of the shoulder. The results of such hemi or total shoulder arthroplasties depend on a combination of factors, including correct patient selection for likely patient compliance with postoperative rehabilitation, surgical technique (in particular, reconstruction of soft tissues) and the patient's motivation to get better, as described by Constant and Welsh (1985).
ARTHROSCOPY
589
Figure 6. Lateral projection of the scapula showing irregularity of the supraspinatus outlet.
Patient selection on the basis of the diagnosis is generally not a problem, and it is usually quite clear on clinical and radiological grounds whether a shoulder replacement would be an appropriate procedure to undertake. What is frequently more difficult to assess is the patient's motivation to undergo the extensive and often long rehabilitation following such surgery. Preoperative assessment by the physiotherapist is now a routine in those cases where motivation is not clearly defined. If compliance with physiotherapy is unlikely to be forthcoming, then major shoulder surgery in the form of arthroplasty is probably better withheld in favour of other methods of treatment for pain relief. Occasionally, shoulder replacement for pure pain relief and nothing more may be considered, but it is important for both patient and surgeon to be aware of this prior to the procedure being undertaken. In those in whom it is unclear whether or not they will comply with physiotherapy postoperatively, an arthroscopy can provide a valuable indication. As well as providing important information regarding the joint surfaces and the condition of the soft tissue, in particular the cuff, an
590
c.R. CONSTANT
arthroscopy allows the doctor to assess patient response to physiotherapy after such a relatively minor procedure. It is the author's experience that patients who do not comply with the relatively simple rehabilitation programme following an arthroscopy of the shoulder in the presence of arthritis, will not undertake the more major rehabilitation requested following major shoulder surgery in the form of arthroplasty. OPERATIVE P R O C E D U R E
The arthroscopic examination is undertaken with the patient under full general anaesthetic; the arm is supported at 45-60 ~ of abduction with slight forward flexion of, perhaps, 30 ~. This position is held either by an assistant or by single or double traction units. The use of a second traction device lifting the arm away from the side helps to achieve better visualization of the joint. The traction weight applied to the arm should be carefully monitored as a brachial plexus palsy may result if excessive traction is applied. A posterior portal is used for the insertion of the scope; a standard arthroscope (30 ~ 5 mm) is used by the author. Prior to insertion of the scope, the joint is distended with saline. A detailed and systematic examination of the shoulder joint, beginning with the biceps tendon and proceeding to the glenoid, surrounding labrum, joint surfaces, soft tissues including glenohumeral ligaments and inferior recess, and finally the posterior aspect of the shoulder joint, is undertaken. Examination of the under-surface of the rotator cuff is followed by insertion of the scope into the subacromial bursa through a rotator cuff tear, if this is present, or through a separate route if the rotator cuff is intact. Assessment of the under-surface of the acromion and the inferior surface of the acromioclavicular joint, as well as the superior surface of the cuff, is made. By rotating the arm in the position of traction, it is possible to visualize the entire surface of the humeral head. It should be noted that there is normally a small bare area in the posterior part of the anatomical neck of the humerus; this should not be confused with a significant Hill-Sachs deformity (depressed crush fracture of the posterior aspect of the anatomical neck associated with anterior dislocation of the shoulder). Instrumentation through a superior portal, between the outer end of the clavicle and the medial part of the acromion, or, more usually, through an anterior portal, inserting the instrument between the middle glenohumeral ligament and the biceps tendon, allows probing and instrumentation within the shoulder joint. The use of hydrodistension, with or without adrenaline, allows adequate haemostasis within the joint while arthroscopy and arthroscopic surgery are being undertaken. The use of an irrigation/drainage cannula with a tap is useful, though not essential. Joint laxity can also be assessed using the probe. The rotator interval is easily seen and can be probed, so that weaknesses in this area, frequently not seen on an arthrogram, can be detected without difficulty. Arthroscopic anatomy of the shoulder and lesions seen arthroscopically were well described by Detrisac and Johnson (1986).
ARTHROSCOPY
591
ARTHROSCOPIC SURGERY OF THE SHOULDER
Arthroscopic surgery of the shoulder should only be considered by those who are fully competent in the art of diagnostic arthroscopy and who are totally familiar with the arthroscopic anatomy of the shoulder, triangulation techniques and the significance of the intra-articular pathology seen. The following arthroscopic surgical techniques may be undertaken in the shoulder joint with varying degrees of success, depending on the skill of the operator. Synovectomy, synovial biopsy and removal of loose bodies
This involves the use of two portals and is probably the simplest of all arthroscopic procedures undertaken in the shoulder. Removal of loose bodies is not as difficult as in the knee because the recesses in which they usually settle are more accessible in the shoulder. Division of the glenohumeral ligaments
Tight glenohumeral ligaments, in particular the middle glenohumeral ligament, are seen in patients with adhesive capsulitis. Following gentle manipulation and hydrostatic distension, division of these ligaments using a retractable arthroscopic knife usually provides significant improvement in passive range of movement under anaesthesia. The division of such ligaments should not extend beyond the shoulder capsule. Fixation of a Bankart labral detachment
Screw, staple or suture fixation of a Bankart labral detachment can be undertaken arthroscopically, although the results have not yet been satisfactorily evaluated in the longer term. The procedures involved in Bankart fixation are difficult and frequently time consuming. The operator should be aware of the need sometimes to revert to an open operation to succeed in stabilizing the joint if arthroscopic methods fail. Subacromial decompression and acromioplasty
Using bursoscopy, either through a rotator cuff tear or by direct insertion of the scope into the bursa, in combination with a power shaver, the subacromial surface may be shaved down to provide a satisfactory acromioplasty/ decompression of the rotator cuff. Bleeding from the marginal artery on the front of the acromion may present a significant problem. Extension of the acromioplasty for the partial excision of the coracoacromial ligament can also be undertaken. An associated rotator cufftear, if not severely retracted, or an interval rotator cuff weakness can be sutured satisfactorily arthroscopically. This particular procedure requires a great deal of experience to achieve a rotator cuff repair successfully.
592
c.R. CONSXANT
CONCLUSION Shoulder arthroscopy can be considered to be a valuable m e t h o d of investigating problems in specific instances. Surgical arthroscopy of the shoulder has a limited place in the treatment of some shoulder disorders. Neither are particularly easy procedures. Arthroscopic surgery requires a great deal of experience and should not be undertaken until total familiarity with diagnostic arthroscopy has been achieved. Complications, when they occur, can be serious and relate entirely to operator inexperience.
REFERENCES Constant CR & Welsh RP (1985) Shoulder Replacement. Berlin: Springer. Dandy DJ (1981) Arthroscopic Surgery of the Knee. Edinburgh: Churchill Livingstone. Detrisac DA & Johnson LL (1986) Arthroscopic Shoulder Anatomy. New Jersey: Slack.