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Chapter XVII

Contents

PART III

SPECIAL TYPES OF BONE AND JOINT

INJURIES

Marshall R. Urist, M. D., and Mather Cleveland, M. D.


CHAPTER XVII

Complete Dislocations of the Acromioclavicular Joint

Marshall R. Urist, M. D.

Up to the end of World War II, no single recorded series of complete dislocations of the acromioclavicular joint consisted of even a dozen cases. Orthopedic surgeons of wide experience in civilian practice seldom encountered more than 3 or 4 cases, if as many, in the course of their professional lives. The mass trauma of combat altered that situation. During the war, several times as many of these injuries were treated by single observers as would have been ordinarily observed in a lifetime of civilian practice. This chapter is based upon the author's personal observation of 41 instances of complete dislocation of the acromioclavicular joint while the 802d Hospital Center was stationed at Blanford, England, during 1944-45 and while the 97th General Hospital was stationed at Frankfurt, Germany, in 1945.

These 41 injuries (tables 7 through 10) were all war connected, though not all were battle incurred. A few were sustained on the football field and a few more in traffic accidents. The remainder were incurred in combat, chiefly during parachute jumps and in the course of hazardous engineering operations. All were of great violence, however they were incurred, as might be expected, because all the casualties were strong, active, young soldiers in the same age group.

Twenty-three of the forty-one injuries were acute and were recognized so promptly that most of the victims received first aid immediately or shortly after the injury. All of this group were evacuated from the combat zone as promptly as possible. Those who were transported by air arrived in fixed hospitals within a few hours after injury. Those transported by water or by rail arrived within 10 days.

In the other 18 cases, the injury was unrecognized or unreported, and therefore untreated, for periods of time ranging from a few weeks to 18 months after it had been sustained.

Eleven of the 41 soldiers, in addition to complete dislocations of the acromioclavicular joint, had associated fractures of various portions of the clavicle, the acromion process, and the coracoid process. One of these patients had 2 fractures. Some of them, as would be expected, were suffering from combat fatigue or other war-related psychosomatic conditions.

*Associate clinical professor of surgery, Division of Orthopedics, University of California, Los Angeles, Calif. Formerly major, MC, AUS.


192

TABLE 7.-Significant data in 18 complete dislocations of the acromioclavicular joint treated in author's splint1

Case No.

Type of joint

Associated fractures

Position at 4 weeks

Ballottement at 4 weeks


Calcification in coracoclavicular ligaments

Cosmetic results

Residual symptoms

Figure references

1

Overriding

---

Excellent

Positive

Present

Excellent

---

50

2

---do---

---

---do---

---do---

---

Good

Pain

---

3

---do---

---

Good

---

Present

Excellent

---

---

4

Overriding, nearly vertical

Acromion,chip

---do---

---

---do---

Fair

---

55

15

Nearly vertical

Clavicle, subchondral

Wide joint space

Positive

---

Subluxation

Pain

52

16

Incongruent, vertical

---

---do---

---do---

Present

Slight subluxation

---do---

---

7

Overriding

Coracoid, avulsion

Excellent

---

---do---

Perfect

---

54

8

---do---

Clavicle, avulsion

---do---

---

---

---do---

---

49

9

---do---

Clavicle, acromial end

---do---

---

---

Excellent

---

46

10

Incongruent, vertical

---

---do---

---

Present

---do---

---

---

11

Overriding

---

---do---

---

---

---do---

---

---

12

---do---

---

Slightly wide joint space

---

Present

---do---

---

---

13

---do---

---

---do---

---

---

---do---

---

---

14

---do---

---

Excellent

---

---

---do---

---

---

15

---do---

---

---do---

---

---

---do---

---

---

216

Vertical

Clavicle, avulsion

Good

---

Present

Slight subluxation

Pain

51

217

---do---

---

---do---

---

---

---do---

Slight pain

45

218

Nearly vertical

---

---do---

Positive

---

Subluxation

---do---

---


1See table 10 for details of later surgical management.
2Splint applied after 10 days of management in adhesive strappings.


193

TABLE 8.-Significant data in 11 complete, late, untreated dislocations of the acromioclavicular joint

Case No.

Type of joint

Primary treatment

Days of healing


Calcification in coracoclavicular ligaments

Osteoarthritis

Cosmetic results

Figure references

19

Overriding

Hunkin cast

56

---

Present

Subluxation

56

20

Vertical

Watson-Jones adhesive splint

58

Present

---

---do---

---

21

Congruent, vertical

---do---

35

---

Present

---do---

---

22

Overriding

Jones humeral splint

34

Present

---do---

Subluxation and Erb-Duchenne palsy

---

23

Underriding

Stimson adhesive splint

395

---do---

---do---

Subluxation

---

24

Vertical

Velpeau adhesive splint

270

---do---

---do---

Dislocation

57

25

Overriding

None

35

---do---

---do---

---do---

---

26

Vertical

Velpeau bandage

70

---do---

---do---

---do---

58

27

Overriding

None

42

---

---do---

---do---

47

28

Incongruent, overriding

---do---

300

---

---

Subluxation

---

29

---do---

---do---

330

---

Present

---do---

---


TABLE 9.-Significant data in 5 complete, variously treated, recent dislocations of the acromioclavicular joint


Case No.

Type of joint

Primary treatment

Cosmetic result

Residual symptoms

30

Overriding, nearly vertical

Skeletal traction

Excellent

Pain.

31

Overriding

---do---

---do---

Slight pain

32

---do---

Phemister transarticular wire

Slight subluxation

---

33

---do---

Coracoclavicular screw

Slight deformity

---

134

---do---

Thoracobrachial spica, 90-degree abduction

Excellent

---


1This patient also had a fissure fracture of the acromion process and an avulsion fracture of the coracoid process.


194

TABLE 10.-Significant data in 9 complete dislocations of the acromioclavicular joint eventually treated by excision of the distal end of the clavicle.   

Case No.

Type of joint

Associated fractures

Primary treatment

Interval before surgery


Operative findings

Cosmetic results

Figure references


Coracoclavicular ligaments

Joint

35

Overriding

Clavicle, subchondral

Stimson strapping

4 weeks

Stretched but intact

Fibrous adhesions

Poor

---

36

---do---

---do---

Watson-Jones strapping

4 weeks

Trapezoid stretched and frayed

Interposed capsule and fibrous adhesions

---do---

---

37

---do---

---

None

3 weeks

Intact

---do---

---do---

---

38

Incongruent, overriding

---

---do---

12 months

---do---

Chronic synovitis or fibrous ankylosis

Dislocation

---

39

---do---

---

Adhesive brachioclavicular sling

11 months

Ossified

Extra-articular new bone

Subluxation

48

40

---do---

Clavicle, transverse of shaft

Arm sling

10 months

---do---

---do---

---do---

53

41

---do---

Clavicle, subchondral

Velpeau bandage

5 months

Intact

Interposed fibrous connective tissue

---do---

---

15

Vertical

---

Author's splint

10 weeks

---do---

Interposed capsule and fibrous adhesions

---do---

52

16

Incongruent, vertical

---

---do---

10 weeks

---do---

---do---

---do---

---


1See table 7 for details of primary treatment.


195

The material in this chapter is presented from three points of view:

1. The anatomicopathologic, which up to the end of World War II was incompletely understood, probably because no single observer had previously encountered a large enough series of cases to permit conclusions.

2. The therapeutic, which had not previously been clarified for the same reason. Up to the end of World War II, in spite of the small number of recorded cases, more than 35 conservative methods of treatment, and at least 28 surgical methods, had been proposed for the management of these injuries. During the course of treatment of these 41 injuries, what seemed to be an improved method of conservative treatment was developed.

3. The prognostic. Up to the end of World War II, very few end results of therapy by any methods had been recorded in the literature.

Anatomic Considerations

Before discussing the pathologic process in complete dislocations of the acromioclavicular joint, certain anatomic facts must be summarized. This joint is made up of two structures, the clavicle and the acromion process, which are maintained in relationship to each other by the acromioclavicular and coracoclavicular ligaments. The coracoclavicular ligaments form a syndesmosis, the term implying a synostosis of a special type in which the skeletal elements are bound together by a continuous band of elastic connective tissue. Whether the coracoclavicular syndesmosis represents a trend toward the development of a diarthrodial joint between the coracoid process and the inferior surface of the clavicle or is simply a metamorphosed joint is still not clear. In about 1 percent of random roentgenograms of the shoulder, the coracoclavicular joint is a well-developed diarthrosis. The acromioclavicular joint itself is a true diarthrosis; the articular surfaces of the acromion process and the outer end of the clavicle, which are separated by a joint cavity, are surrounded by a capsule which is reinforced by ligaments. The motion of the acromioclavicular joint is synchronous with the motion of the shoulder joint. There is, however, no motion of the coracoacromial syndesmosis (represented by the coracoacromial ligament), and it can be sacrificed without effect on the function of the shoulder. Its functional significance is, therefore, not apparent.

As part of this study, 100 unselected roentgenograms of the shoulder area were examined, to determine possible variations in the form of the acromioclavicular joint and to confirm or disprove the impression that they are frequent. These films were all taken by the standard Army technique, and the patients on whom they were made had no symptoms referable to the shoulder. The only selective consideration was that such variations as existed be present bilaterally. The clinical impression that there are numerous variations in this joint was promptly confirmed. Only infrequently, in fact, was the roentgenogram entirely in accord with the classical anatomic description. The explanation probably is that the articulation is made up of parts which are formed at


196

different stages of the morphogenesis of the typical diarthrosis and that its normal evolutionary development is frequently interrupted.

In these particular roentgenograms, the following variations from the classic norm were observed: The articular surfaces were occasionally separated by a meniscus attached to the superior acromioclavicular ligament. Sometimes the meniscus took the form of a blade of fibrocartilage which extended halfway into the joint. Sometimes it formed a complete disk which divided the joint into two parts. In one case, no diarthrosis was present; the joint was represented merely by a pad of fibrous tissue attached to the outer end of the clavicle, with no evidence of an articular cavity. This is not an uncommon observation. The joint surfaces were often incongruent. The outline of the articular surface of the acromion process sometimes corresponded to the outline of the clavicle, but often it did not. Sometimes no part of the clavicle opposed the end of the acromion; then the patient, for all practical purposes, had a congenital subluxation or relaxation of the acromioclavicular joint. The clinical prominence of the acromioclavicular joint was usually determined by the degree of overriding of the acromial end of the clavicle. Sometimes the joint surfaces lay in a vertical plane (fig. 45, case 17). Sometimes the acromion partly overlay the clavicle (fig. 46, case 9). In the majority of roentgenograms, some overriding of the clavicle on the acromion was observed (fig. 47, case 27).

FIGURE 45 (case 17).-Roentgenogram of severe dislocation of right acromioclavicular joint sustained in motorcycle accident. Joint is of vertical type. Interposition of capsular ligament was suspected in this case, because joint space was greatly increased on affected side after reduction of dislocation.


197

FIGURE 46 (case 9).-Roentgenogram showing dislocation of right acromioclavicular process, with minute fracture of distal end of inferior margin of clavicle, 7 weeks after injury was sustained in tank striking tree in combat. Note calcification of inferior capsular ligament. At this time, the patient complained of pain and had limitation of abduction of arm beyond 90 degrees. The intact joint is partly underriding at the inferior margin because the articular surface of the clavicle is concave and the acromial surface is convex.

The shape of the distal end of the clavicle also varied, being bulbous, square, fusiform, flattened, or cylindrical.

When the material was analyzed statistically, it was found that the articular surface of the clavicle overrode the articular surface of the acromion process in 29 of the 100 roentgenograms. The articular surfaces of the acromion and clavicle were nearly vertical and lay in the same plane in 27 cases. The inferior margin of the articular surface of the clavicle overrode the superior margin of the acromion in 3 cases. In 21 cases, the articular surfaces were incongruent. In 9 the clavicle overlay the acromion. In 6 the inferior margin of the clavicle underrode the superior margin of the acromion. In 6 cases, finally, the articular surfaces were not in contact at any point.

Mechanism of Injury and Nature of Lesion

It would be a far simpler matter to explain the mechanism of injury in these 41 dislocations of the acromioclavicular joint if the soldiers had been able to supply more information. They knew the general circumstances of


198

FIGURE 47 (case 27).-Roentgenogram showing dislocation of left acromioclavicular joint 4 months after injury had been sustained in fall from moving tank. Note calcification of capsular ligament (indicated by arrow) which was associated with mild symptoms of traumatic arthritis. This patient presented an extreme example of the overriding type of joint with nearly horizontal articular surfaces.

injury but most of them could provide no precise details. In two cases, ecchymoses and abrasions indicated the point of contact of external force. One patient (case 40) had a discoloration over a fracture of the clavicle, and the other (case 34) had been struck over the acromion process by a falling steel beam. In most cases, reconstruction of the injury in correlation with the clinical and roentgenologic findings suggested that the men had been struck (or had fallen) on the dorsum or the anterior aspect of the shoulder and that the scapula had thus been forced downward or backward.

There were no illustrations in this series of two mechanisms of injury which have been reported in the literature. In one, the scapula is drawn forcibly inferiorly and anteriorly by a sudden change in the position of a heavy burden that is being carried; in the other, the coracoid process comes into contact with the clavicle, and the joint is literally pried apart by force transmitted through the arm.

Illustrations in current textbooks were of little help in dealing with complete dislocations of the acromioclavicular joint, since they were (and continue to be) based on the concept that this injury cannot occur without tearing of the conoid and trapezoid ligaments. Neither past experience, as derived from the literature, nor the evidence of these 41 cases supports that point of view. When the distance between the clavicle and the coracoid process is greatly increased, as it may be in this type of injury, in comparison with the


199

distance between these structures in the uninjured shoulder, the coracoclavicular ligaments are correspondingly stretched and may be sprained, but it does not follow that they must be torn. In some cases in this series, in fact, in which force was transmitted through the arm, it was entirely conceivable that the joint capsule took the full force of the blow or fall and that the ligaments suffered no damage at all.

In unreduced dislocations of the acromioclavicular joint, the deformity was maintained by three factors, (1) gravity, (2) the pull of the trapezius on the distal end of the clavicle, and (3) the absence of counterpull by the aponeurosis of the anterior portion of the deltoid. When the arm on the affected side was weighted, the scapula, and with it the acromion process, was drawn downward and forward, so that the gap in the joint was increased both anteroposteriorly and superoinferiorly. In several doubtful cases in this series, this maneuver was used to accentuate the suspected lesions in the roentgenograms.

Pathologic Process

No fresh material was available for examination, since United States Army Medical Department policy was to treat acromioclavicular dislocations conservatively and not to resort to surgery until the lapse of a sufficient time after injury to permit healing or to establish the existence of a residual disability. It was possible, however, to study the process of healing after complete dislocation in 9 cases in which resection of the distal end of the clavicle was necessary at intervals varying from 3 weeks to 1 year after injury.

In each of these nine specimens the coracoclavicular ligaments, while stretched and elongated, had healed in complete continuity. The texture of the ligaments ranged from cicatricial induration to bony hardness. Elongation and scarification were proportional to the distance between the outer end of the clavicle and the coracoid process, but bony tissue was not always identified. The joint capsule, as the result of the healing process, showed an increase of thickness in every specimen, sometimes up to 4 mm.

Late changes were less uniform. In five cases, the articular surfaces were obliterated and replaced by fibrous connective tissue. In two of these cases, interposed flakes of cartilage, fibrocartilage, and necrotic hyalinized material were regarded as remnants of capsular ligament and meniscus, presumably separated at injury. In five cases, osteoarthritic changes, such as bony eburnation and marginal spurs, were observed. In two cases, there was evidence, which had not been present in the roentgenograms, of subchondral compression fractures of the clavicles and acromion processes. In one case (fig. 48, case 39), loose osteocartilaginous bodies were present.

The changes observed in these late specimens were in accord with those observed by Gurd1 in fresh cases. In 1 of his cases, complete dislocation of the

1Gurd, F. B.: The Treatment of Complete Dislocation of the Outer End of the Clavicle. A Hitherto Undescribed Operation. Ann. Surg. 113: 1094-1098, June 1941.


200

FIGURE 48 (case 39).-Roentgenogram showing healed dislocation of acromioclavicular joint 10 months after patient was kicked squarely on point of shoulder in football game. Note loose osteocartilaginous bodies in joint (indicated by arrow) and ossification of insertions of trapezoid ligament. The patient was subjected to surgery because of annoying crepitations, with pain, while doing heavy work, and because he had 30 degrees of limitation of abduction.

clavicle occurred without complete rupture of the coracoclavicular ligaments. In other cases, stretched or ruptured ligaments were found at open operation for repair of conoid and trapezoid ligaments with fascia lata.

Experimental observations-For further elucidation of the mechanism of injury in complete dislocations of the acromioclavicular joint, a number of observations were made on cadavers:

1. The coracoclavicular ligaments were transected through a stab incision, after which the acromial end of the clavicle was grasped with bone forceps and tested for motion. The motion produced did not differ perceptibly from the motion possible on the opposite, intact side, nor did subluxation occur on the transected side when strong traction was applied to the arm.

2. The superior acromioclavicular ligament and the entire joint capsule were transected through an incision overlying the joint. It was then possible to produce an incomplete dislocation of approximately 50 percent. The incision was next carried around the outer end of the clavicle in U-shaped fashion, and the attachments of the deltoid and trapezius muscles to the clavicle were divided. The end of the clavicle was then drawn upward and posteriorly. This made it possible to accomplish complete disarticulation. When, however, the end of the clavicle was pulled straight upward, only incomplete disarticulation could be produced. When the coracoclavicular ligaments on the same


201

side were cut, as previously described, the entire outer end of the clavicle could be disarticulated farther upward than when only the attachments of the deltoid and trapezius muscles were divided.

3. The trapezoid ligament, the deltoid and trapezius attachments to the clavicle, and the superior acromioclavicular ligaments were all dissected and divided. It was then possible to move the clavicle posteriorly or superiorly and produce complete dislocation.

4. The experiment just described was repeated, except that the conoid ligament was sectioned instead of the trapezoid. The same results were accomplished as in the previous experiment, except that the acromial end of the clavicle could be dislocated farther upward.

5. The third and fourth experiments were repeated, except that the coracoacromial ligament was sectioned, first alone and then in combination with each of the other ligaments. There was no perceptible alteration in the stability of the acromioclavicular joint.

Similar observations had been reported in the literature before these were undertaken, and the same conclusions had been drawn from them, with one exception: The observations made in World War II were thought to emphasize the predominant role played in complete dislocation of the acromioclavicular joint by the joint capsule and the attachments of the deltoid and trapezius muscles. When these structures were severed, to simulate the tearing or stretching which they undergo in dislocation of the joint, the outer end of the clavicle could be completely dislocated without injury to the conoid or trapezoid ligaments. Greater displacement of the clavicle was possible when the conoid and trapezoid ligaments were sectioned, but the alteration was quantitative not qualitative. Section of the conoid or the trapezoid ligament alone had no perceptible effect, as might have been expected, since there is no separate excursion of the bones united by these structures. In the interpretation of these results, however, it was necessary to bear in mind Cadenat's2 warning that in the living subject the relationships of parts in the functioning joint are probably altered by the tone and action of surrounding muscles and that the elasticity of individual ligaments may vary, depending upon the necessity for synchronizing the motions of the clavicle with those of surrounding parts.

Both the pathologic and the experimental observations in this series of dislocations suggested that the clavicle can become completely dislocated without rupture of the coracoclavicular ligaments. It was also apparent that the trapezoid ligament is occasionally stretched in acromioclavicular dislocations and that still more infrequently it is grossly ruptured. Microscopically, it had to be assumed that individual fibers of both the conoid and the trapezoid ligaments are torn during injury, but the observations made in this study indicated that the capacity of these ligaments for both healing and repair is excellent and can be relied upon for reconstitution of the joint relationships.

2Cadenat, F. M.: The Treatment of Dislocations and Fractures of the Outer End of the Clavicle. Internat. Clin., Series 27, 1: 145-169, 1917.


202

Diagnosis

Diagnosis in this series of cases was made on the history of the injury, the clinical evaluation of the symptoms, the physical findings supplemented by certain objective tests, and the roentgenologic findings.

In the acute case, there was considerable pain. In the untreated or recurrent case, after joint effusion and periarticular swelling and tenderness had disappeared, which was usually by the end of the third week, there was little pain in a complete dislocation with overriding if there was no contact between the clavicle and the acromion process. Unless they were called upon to do hard work, most soldiers with nonacute injuries tended to make light of their symptoms.

In some cases, residual subluxation following the conservative treatment of complete acromioclavicular dislocations gave rise to pain, annoying crepitation, and sometimes limitation of joint motion. In such cases, there was an unsightly protrusion of bone on the shoulder. Some soldiers, like men in civil life, were willing to disregard the deformity if the symptoms were not severe. In other cases, the complaints were disproportionately greater than the clinical and roentgenologic evidence indicated that they should be.

In these circumstances, a number of simple tests proved useful. When they were positive, it was assumed that there was a physical basis for the complaints.

1. When the man leaned against the wall, so that the inferior angle of the scapula was firmly and sharply pressed into the posterior aspect of the thorax, pain was felt in the acromioclavicular joint.

2. When the man elevated his arm and pain was experienced on the affected side, it was assumed that synovitis, fibrous ankylosis, or arthritis of the injured joint was present. Full elevation of the arm was sometimes impossible.

3. When the man shrugged his shoulder, rotated the arm internally, or carried a weight, palpable crepitations or subjective grating sensations were accentuated. A 35-pound bucket of sand in each hand was used routinely to amplify the deformity for roentgenologic purposes.

4. Crossing the elbows on the chest in the position of adduction might be impossible because of pain in the joint or ankylosis.

Management

As in all injuries of this kind, the purpose of treatment in dislocations of the acromioclavicular joint was twofold, to secure anatomic reposition and to relieve symptoms. Unfortunately, although the objectives are obviously interrelated, the accomplishment of one objective did not necessarily result in the accomplishment of the other. After perfect anatomic restoration of the joint, symptoms sometimes persisted in these cases, as in many other reported cases, because there was residual damage to the articular surface and joint capsule. In other instances, there were no residual symptoms, but the anatomic result was poor.


203

Recurrence of the dislocation furnished the same problems that it does in civilian practice. In a number of instances, although clinically and roentgenologically the bones were in perfect position after immobilization for the accepted length of time, the dislocation recurred as soon as the splint was removed, showing that healing had not yet been sufficient to reestablish the continuity of the periarticular ligaments. Subluxation recurred in 5 of the 18 cases treated conservatively in this series (table 7). According to the literature, residual subluxation or some degree of disability occurs in 10 to 20 percent of all cases managed by this method.

Conservative Management

The necessity for standardization of treatment underlay all Army policies, including the policy that complete dislocations of the acromioclavicular joint should be treated conservatively for a certain period of time before it was concluded that this method would not be effective. Some of the data in this series suggest that there may be ways of determining in advance which cases will, and which will not, be responsive to conservative measures. It was found, for instance, that men who had overriding clavicles frequently were symptomless after conservative treatment (table 7), while those with vertical or partially overriding joints presented complications (table 9). Two patients with this type of joint (case 5, table 7 and case 41, table 10) had subchondral compression fractures.

Although conservative treatment was necessarily used in fresh cases because of Army policies, better results might have been obtained if more flexibility had been permitted. It would probably have been wiser to resort to surgery at once in untreated cases and neglected cases.3 It would also have been wiser to resort to it without further delay, if improvement was not evident at the end of 3 or 4 weeks of properly applied conservative measures. Finally, complete dislocation of the outer end of the clavicle did not respond well to conservative methods, and some degree of deformity was inevitable if surgery was not done. A correct evaluation of the patient was, of course, an essential part of the decision to undertake operative measures.

Conservative management included various techniques of manipulation and reduction, followed by various methods of immobilization.

Manipulation and reduction-The following methods of manipulation were employed in this series to correct the deformity and reduce the dislocation before the application of splints:

1. Pressure was exerted with the thumb over an appropriately placed small felt pad, in order to depress the prominent distal end of the clavicle.

2. The scapula and acromion process were elevated by elevation of the flexed elbow.

3This argument is necessarily theoretical. As long as combat conditions prevailed in the European Theater of Operations, no elective surgical procedure was permitted unless the soldier could be returned to full field duty after it within 120 days. (Editor's note.)


204

3. These two methods were used in combination in most cases to obtain the desired position for immobilization in a brachioclavicular splint. The patient's role in both was passive.

4. The patient, lying supine, threw his shoulders back and abducted his arm 90 degrees or more, or hyperextended his head, to relax the pull of the trapezius on the outer end of the clavicle.

5. The patient, standing erect, either threw his shoulders upward and backward or abducted the injured shoulder 90 degrees or more. This maneuver, as well as the maneuver described under heading 4, could be carried out by the surgeon rather than performed actively by the patient, if that was more convenient.

Reduction of the dislocated joint was, as a rule, easier than maintenance of the optimum position for the necessary 6 weeks. In the occasional case, however, there were several obstacles to successful reduction. Sometimes the clavicle slid into position and rotated on its long axis (case 5, table 7). Sometimes it lay posterior to the acromion process, even when held down at the correct level by manual pressure (case 4, table 7). As has already been intimated, it was found, when some of these patients came to surgery for excision of the distal end of the clavicle, that the source of these difficulties was interposition of meniscus, frayed ends of capsular ligament, and flakes of articular cartilage between the joint surfaces.

6. If the acromioclavicular joint was ruptured as well as dislocated, the deformity could be overcorrected by pushing the clavicle down below the level of the acromion process. In the two cases in this series (fig. 49, case 8; cases 8 and 18, table 7) in which immobilization was carried out in this position, both cosmetic and functional results were excellent.

Immobilization-Various types of splints and other techniques of immobilization were used to maintain the extremity in position until healing oc-

FIGURE 49 (case 8).-Roentgenogram [retouched] of left acromioclavicular dislocation sustained in motorcycle accident, after reduction and overcorrection in author's splint. Arrows indicate points of main pressure of shoulder strap on clavicle. The clavicle has been depressed below the level of the acromion process.


205

curred, which was theoretically at the end of 6 weeks, or until it was evident that conservative management would not be successful.

One of the eleven patients seen late and not treated (case 26, table 8) had been put up in a Velpeau bandage, which had had no effect on the dislocation. Otherwise, slings and bandages were not used in this series except immediately after injury, for first aid. Some of the older surgeons devised complicated bandages to be applied by complicated techniques, but modern orthopedic surgeons had had little experience with these methods. They give very uneven results and have the additional disadvantage that if the bandages and slings are to be effective for any length of time, they must be painfully tight.

Four of the eleven patients seen late and not treated had been put up in various types of adhesive splints by the surgeons who first treated them, but in no instance had the result been satisfactory (cases 20, 21, 23, and 24, table 8). Otherwise, adhesive dressings and strappings were not used in this series for definitive treatment. Even the use of protective felt boards, coaptation splints, elastoplast, and other modern elastic materials does not eliminate the fundamental objection to this method, namely, that perspiration and skin irritation make the patient extremely uncomfortable and that removal and reapplication of the dressing, which is necessary at intervals if position is to be maintained, are unpleasant procedures for physician as well as for patient.

Suspension of the extremity in 90 degrees or more of abduction, by means of the Balkan frame or some similar device, is a useful method in the management of incomplete dislocations in bedridden patients but of rather doubtful value in complete dislocations. It was not indicated in any case in this series. Harnesses and braces were also avoided. The patient must be under constant supervision when they are used; they require a considerable degree of cooperation from him, which is not always forthcoming, and better results can be secured by less complicated methods.

Plaster immobilization-Nineteen of the patients in this series who were seen early or relatively early (within 10 days) were treated conservatively, with immobilization in plaster splints for approximately 6 weeks. Another patient (case 19, table 8) who was seen late, had also been treated by plaster immobilization, in a sort of hanging (Hunkin) cast, which had left him with a subluxation. This cast is a loose, plaster torso cast, suspended from a webbed shoulder strap. It has the serious disadvantage that the effort to maintain reduction is relaxed when the patient is recumbent. The Gibben splint has the same objection. The Gibben, a hanging arm cast suspended from an elastic band over the shoulder, functions on the same principle as the Hunkin splint-that the weight of the plaster will depress the outer edge of the clavicle.

The thoracobrachial spica, with 90-degree abduction, recommended by Key and Conwell,4 was used in one fresh case (case 34, table 9) with excellent results.

4Key, John A., and Conwell, H. Earle: The Management of Fractures, Dislocations, and Sprains, 3d ed. St. Louis: The C. V. Mosby Co., 1942.


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Case 34.-An engineer, working with a crane, was struck on the left shoulder by a falling steel beam. Roentgenologic examination an hour later showed a linear fracture of the acromion process without displacement, avulsion of the coracoid process, and acromioclavicular separation. The plaster abduction splint of Key and Conwell was considered more practical in this case, because of the swelling and ecchymosis over the dorsum of the shoulder, than a splint which required the pressure of a shoulder strap to be effective. The dorsal section of the cast was removed at the end of 2 weeks, and massage and biceps-setting exercises were ordered. The remainder of the cast was removed 4 weeks later, and limited exercises were undertaken. At 8 weeks, use of the shoulder wheel was begun. Roentgenologic examination at this time showed union of the coracoid process and the scapula, with complete healing of the fracture of the acromion process. When the man returned to duty 12 weeks after the accident, he had a slight subluxation but was free of symptoms. When the cast was first removed his shoulder had been painful and stiff.

The Key-Conwell cast only partially reduces the acromioclavicular separation, because the distal end of the clavicle is displaced slightly posteriorly, and the distance between the clavicle and the acromion process is undesirably increased. It should therefore be employed only on special indications, such as existed in this case. This case is an excellent illustration of the justification for the general policy in military practice that a sufficient period of conservative therapy be tried before surgery is resorted to. The dislocation was associated with fractures of the coracoid and acromion processes, and, as in all such cases, management was a compromise, in an endeavor to secure comfortable immobilization.

A number of available casts were considered and deliberately rejected for these fresh cases. Legg, among others, devised a brachioclavicular cast which is a Velpeau bandage with an elastic shoulder strap added to depress the clavicle. The objection to the use of such casts in combination with shoulder straps is that the pressure of the strap in brachioclavicular slings, when the scapula is not elevated, is usually too much for skin tolerance over a 6-week period. This is particularly true if techniques which utilize suspension and gravity are employed.

The torso cast recommended by Dillehunt5 elevates the acromion process until it is alined with the distal end of the clavicle, by fixation and elevation of the arm at the side of the chest (fig. 50B). Reduction and immobilization are accomplished with the expenditure of very little force, because the pull of the trapezius is counteracted, while at the same time the weight of the arm is canceled out.

The author's splint (fig. 50) was devised to incorporate the most desirable features of the splints devised by Dillehunt and Howard. As in Dillehunt's splint, elevation of the scapula is maintained by anchoring the body plaster to the iliac crests, to provide the necessary counterbalance. Neither of these splints, however, provides for overcorrection of the deformity by depression of the clavicle below the level of the acromion process, which is necessary for optimum cosmetic and functional results. In the author's modification, a broad elastic shoulder strap, made of a strip of salvaged inner tube, provides

5Dillehunt, R. B.: Luxation of the Acromioclavicular Joint. S. Clin. North America 7: 1307-1313, October 1927.


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the necessary clavicular depression, while at the same time excessive cutaneous pressure is avoided. The main objection to this splint seems to be that it restricts movement of the arm and chest.

This splint was used in 18 cases in this series (table 7), in 15 of which it was applied promptly after injury.

Results-The 15 patients just referred to were evacuated promptly from forward areas in first-aid bandages or temporary adhesive splints. They wore the author's splint for 6 weeks and had had 2 weeks of physical therapy before the first record of results was made, though in each instance, after the splint had been worn for 3 to 4 weeks, the shoulder strap was turned medially on itself, and the mobility of the acromial end of the clavicle was determined.

In no instance did the splint cause any disability in the elbow. Twelve patients were returned to duty completely cured after a period of physical therapy and rehabilitation (table 7). Another (case 4) was left with a subluxation but without significant pain or limitation of motion. He was also returned to unrestricted military duty, and followup showed that activity had not increased the deformity.

The two remaining patients (cases 5 and 6) presented subluxations associated with pain, swelling, tenderness, and deformity after several days of physical therapy. When they were operated on later, the capsular ligaments were found interposed between the joint structures, and interference with satisfactory reduction of the dislocations was evident, although it had not been observed in the anteroposterior roentgenograms. This finding, as will be pointed out later, could have been predicted.

Twelve successes in fifteen early cases handled by the author's splint are about in accord with the results of other observers with newer methods of conservative treatment. It should be emphasized, however, that this report concerns only complete dislocations. Many successes reported with strapping and similar obviously inadequate methods of treatment concern only sprains, subluxations, or incomplete dislocations of minor degree, such as the football type of injury sustained in blocking.

The three other patients treated by the author's splint (cases 16, 17, and 18, table 7) were seen 10 days after injury, when they were transferred to it from the adhesive strappings originally applied for first aid. At the end of 6 weeks of immobilization, all presented subluxation of some degree, but associated symptoms were neither severe nor disabling. One of these patients (case 16) who also had an avulsion fracture of the clavicle, had more pain than the other two patients, whose dislocations were uncomplicated, but all three were perfectly satisfied to return to full duty without further treatment.

Two tests used in the course of conservative therapy seemed useful in determining the results being accomplished:

In some patients (fig. 51, case 16; fig. 45, case 17) roentgenograms taken 1 week after reduction showed measurable widening or separation of the joint space. These were cases in which the outer end of the clavicle was characteristically above and posterior to the acromion process and in which it had ap-


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FIGURE 50 (case 1).-Application of author's splint. A. Separate application of padded arm and body plasters. B. Elastic shoulder strap, made of strip of salvaged inner tube, is stretched tightly over clavicle. The tube ends are doubled back on themselves between layers of plaster bandage, to maintain constant pressure.

FIGURE 50.-Continued. C. Elastic shoulder strap in place. Scapula elevated, as in method of Dillehunt. Arm section of plaster fixed to body section and elevated so that shoulder on affected side is 1 to 2 inches higher than shoulder on intact side. D. Continuous pressure maintained by wide area of shoulder strap. Support of body plaster on iliac crests furnishes countertraction and aids in maintaining elevation of arm on body.


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FIGURE 50.-Continued E. Roentgenogram of patient shown in figure 50A through 50D, showing dislocated left clavicle before treatment. Note overriding type of joint. F. Roentgenogram showing reduction of dislocation in Urist splint. Note slight over-correction of dislocation, as shown by comparison of distances between coracoid process and clavicle in reduced joint in this roentgenogram and intact right joint shown in figure 50E.

parently been possible to reduce the dislocation and obliterate the deformity. In these cases, when both clavicles were outlined with the fingertips, it could easily be demonstrated that, while the upward displacement of the dislocated clavicle had been corrected, there was still slight posterior displacement. These were both delayed cases, in which further manipulations would not have been effective. In earlier cases it should be possible to correct the position.

In five cases in this series, ballottement or free floating of the distal end of the clavicle was observed after 3 weeks or more of conservative treatment. It was particularly striking in two cases (cases 4 and 5), both of which were instances of posterior displacement. In each case, ballottement was evident when, at the end of 3 weeks, the shoulder strap of the splint was turned back and the distal end of the clavicle was pushed inferiorly and anteriorly, in an attempt at adjustment. When the splints were removed at the end of 6 weeks, the dislocation in each case was only partially corrected, and subluxation was evident during the 3 weeks of rehabilitation. In both cases, pain and a sense of instability later required excision of the distal end of the clavicle. In both cases, as already noted, the interposition between the joint surfaces of fibrous connective tissue, capsular ligament, and torn meniscus, clearly prevented accurate reposition and presumably accounted for the ballottement observed earlier. In three other cases, there were similar but less conspicuous findings at operation.

At the end of 3 weeks, uncomplicated or well-reduced dislocations of the acromioclavicular joint ordinarily become stable, because the capsular ligament has healed and the attachments of the deltoid muscle are repaired. This is not a large enough number of cases to warrant conclusions, but it may well be that the finding of a free-floating clavicular end at this time indicates the unlikelihood of success with conservative measures and the necessity for an early resort to surgery.


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FIGURE 51 (case 16).-Roentgenogram showing severe dislocation of right acromioclavicular joint after reduction in author's splint. The injury was sustained in a fall over a fence, on a dark battlefield. A false impression of overcorrection of deformity may be obtained when, as in this case, the clavicle is displaced posterior to the acromion but is actually farther from the coracoid process than on the opposite side.

The following case history is another illustration of the good results which can follow properly applied conservative treatment:

Case 1.-A soldier who was sitting in the front seat of a jeep was thrown out after a head-on collision with another vehicle, striking his left shoulder on the pavement and sustaining a complete dislocation of the clavicle (fig. 50E). A Velpeau bandage applied in a local dispensary did not maintain satisfactory reduction. Twenty-four hours later, the dislocation was reduced and the shoulder put up in the author's splint (fig. 50A, B, C, and D), in which it was maintained for 6 weeks. Physical therapy was carried out for 10 days, and 4 days later the man was discharged to full duty, with no restrictions on calisthenics or sports. Roentgenographic examination at this time (fig. 50F) showed the structures in correct anatomic position. There was slight induration on palpation of the joint, with slight crepitus, but the patient had no symptoms and had full range of motion.

Surgical Measures

The end results in arthrotomy, internal fixation, and other surgical measures used in acromioclavicular dislocations depend, just as the end results of nonsurgical measures, upon healing of the ligaments and periarticular structures. In neglected and old lacerations, good results are unlikely. The theoretic advantages of management by arthrotomy include accurate fixation of the nonosseous parts of the joint by reposition and suture under direct vision, but the literature does not suggest that the results are any better cosmetically, symptomatically, or functionally than are achieved by improved conservative measures.

Arthrodesis was a fairly popular method of management in the days when suture operations on the joint frequently resulted in ankylosis. It was the practice in these cases to resect the articular cartilages later, to insure bony fusion, correct deformity, and relieve pain. Limitation of motion of the shoulder, particularly abduction, was explained by experimental observations on the cadaver, which showed that the articulations of the clavicle, scapula, and humerus must function independently for elevation of the arm. Arthrodesis


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continues to be mentioned by occasional observers as a solution of the problem of complete dislocation, but it is not an acceptable procedure in modern orthopedic surgery, and it was not performed, or even contemplated, in any case in this series.

Syndesmoplasty and ligamentopexy were also not employed in this series. No conclusive data on the results of syndesmoplasty had been reported up to World War II, and there are theoretic objections to the operation, the chief being that repair of the conoid and trapezoid ligaments is probably impossible because they are still inaccessible after the widest possible exposure. Suture has been accomplished by indirect methods, such as binding the clavicle to the coracoid process with heavy silk or wire, or repairing the periarticular ligaments by transfer of fascia or tendons at the site of the lesion.

There has never been agreement about the value of ligamentopexy. Reconstruction of the conoid and trapezoid ligaments with an isograft of fascia lata is theoretically valuable in old dislocations with extreme deformity, but if the grafts stretch, the deformity will recur and will be increased by postoperative stiffness of the shoulder. Furthermore, the fascia or old ligaments frequently calcify, and the resulting synostosis limits abduction.

One patient in this series (case 32, table 9) was treated by open reduction and internal fixation with Phemister's transarticular wire. He was left with slight luxation but no residual symptoms.

Two patients were treated by skeletal traction (cases 30 and 31, table 9). They had excellent cosmetic results but some residual pain. This is an excellent method for patients who have sustained other injuries which require confinement to bed, since it assures maintenance of the anatomic position continuously for the desired length of time. It is not, however, suitable for either industrial or military practice; it requires great skill and judgment, and it carries the risk of infection and of injury to nerves and blood vessels. Finally, it can be used only in fresh injuries, and even in them it is associated with all the disadvantages inherent in the use of external skeletal fixation.

When skeletal traction is correctly employed, traction is obtained by the use of small threaded pins; two are inserted into the outer third of the clavicle and another is inserted into the coracoid process, all three being tied into a triangle with rubber bands. These bands serve, in effect, as a second, external set of ligaments, and reduction is obtained by continuous skeletal traction. The patient, to relieve the tension, involuntarily elevates the shoulder on the affected side and thus actively aids in maintaining the reduction.

One case (case 33, table 9) was managed primarily by a coracoclavicular screw. The patient was left with a slight deformity but no residual symptoms. Because of bone resorption, however, the screw became loose 4 weeks after it was inserted. It had to be removed and another splint applied. This method was introduced by Boardman M. Bosworth6 in 1941 and, therefore, had not

6Bosworth, B. M.: Acromioclavicular Separation. New Method of Repair. Surg., Gynec. & Obst. 73: 866-871, December 1941.


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had a wide trial when the United States entered World War II. Watson-Jones,7 who recommends the removal of the screw in most cases after 4 to 6 weeks, considers the results better than those accomplished by conservative methods. Since he advanced this opinion in 1943, he was presumably referring to the use of adhesive strappings, not to the newer conservative techniques.

The coracoclavicular screw is applicable only to fresh injuries. It seems highly doubtful that patients who do not respond to conservative therapy, because of the interposition of soft parts between the joint structures, will be benefited by it. Theoretically, it is open to all the objections applicable to operative methods which do not include arthrotomy. Since the clavicle rotates on its long axis with abduction, it is hard to see how it could move normally when this method of fixation has been employed. The effect on the shoulder as a whole, in fact, seems the same as the effect of fusion of the acromioclavicular joint. Fixation of the clavicle to the scapula limits abduction of the arm and causes pain if motion is attempted beyond 90 degrees.

Surgical excision of the outer end of the clavicle was used in nine cases in this series (table 10) after conservative methods had failed. The cosmetic results (fig. 52, case 5) were excellent in all cases, the contour of the dorsum of the shoulder being maintained by the acromion process. Neither the function nor the appearance of the shoulder, however, could be described as normal in any case.

Prior to World War II, this operation had frequently been used in such conditions as osteomyelitis, arthritis, and tumors, and it had been used, though less frequently, in both fresh and old dislocations of the acromioclavicular joint. These experiences, as well as observations on persons with partial or complete congenital absence of the clavicle, had led to the conclusion that the patient with this type of defect was far better off than the patient with acromioclavicular ankylosis, and that the only disability after operation is a possible slight impairment of the muscular coordination needed for forceful forward thrusts of the arm or for acrobatics.

The results in these nine cases, while satisfactory, do not fully bear out these observations. Careful study of these men showed that the intact clavicle acts as a kind of yardarm, which prevents the shoulder from falling anteriorly and inferiorly onto the chest wall (fig. 52A). This is probably its most important function in man. These were all young men, and the musculature of the shoulder girdle compensated for the stability lost with excision of the clavicle. All of them, however, admitted to rapid fatigue or slight weakness of the affected shoulder as compared with the intact shoulder when they engaged in prolonged vigorous exercise, though within a few weeks of surgery all had been relieved of pain and disability.

In all nine cases, the operation consisted of resection of from 6 to 8 cm. of clavicle, which excluded the clavicular stump from interference with the motions of the scapulohumeral joint. Suture of the cut end of the clavicle to

7Watson-Jones, Reginald: Fractures and Joint Injuries, 3d ed. Baltimore: Williams & Wilkins Co., 1943, vol. 2, pp. 433-435.


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FIGURE 52 (case 5).-Results of excision of outer end of clavicle in complete dislocation of the left acromioclavicular joint, sustained in football game, after failure of management in author's splint. A. Photograph 10 days after operation and just after removal of sutures from incision, through which coracoclavicular ligaments were also explored. Note that affected shoulder is slightly lower than intact shoulder as scapula falls forward and lower on thorax. B. Photograph 15 days after operation. Range of active abduction is 90 degrees. C. Photograph 21 days after operation. Full elevation of arm is now possible.  D. Photograph 28 days after operation. Painless crossing of elbows on the chest, which is now possible in this case, is seldom possible with any appreciable acromioclavicular separation.

the coracoid process with nylon sutures, as advised by Rowe,8 was not regarded as an essential part of the procedure and was omitted in all cases.

The following case reports illustrate both the indications and the results of this method of surgery:

Case 5-This soldier was injured when, in the course of a football game, he was struck sharply over the dorsum of the shoulder by an opponent who blocked him out of a line play. A Velpeau bandage was applied as a first-aid measure and was replaced 2 days later by the author's splint. Roentgenograms showed excellent reduction, but there was slight widening of the acromioclavicular joint as compared with the joint on the opposite, intact side. Examination 4 weeks after injury showed the distal end of the clavicle to be abnormally mobile and apparently floating free. The splint was removed at 6 weeks, and daily exercises were begun at the shoulder wheel. At 8 weeks, there was 30 degrees of limitation of motion

8Rowe, M. J.: Nylon Bone Suture. Surgery 18: 764-768, December 1945.


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FIGURE 53 (case 40).-A. Roentgenogram of old dislocation of left acromioclavicular joint with linear fracture at junction of middle and outer thirds of clavicle. Ecchymosis and marked swelling were present over lateral aspect of neck and dorsum of shoulder immediately after injury. Note synostosis (indicated by arrow) at site of fracture. B. Roentgenogram [retouched] after excision of outer third of clavicle. Patient had complete relief of symptoms and returned to full duty in 12 weeks. C. Superior and inferior aspects of excised clavicle. Note new bone formation on anteroinferior attachments of trapezoid ligament.

when the arm was elevated, and pain and crepitus were experienced during exercises at the shoulder wheel. When the arms were folded across the chest, the distal cud of the clavicle rose out of the joint. Ten weeks after injury, when it was evident that the man had full justification for his continued complaints, the distal end of the clavicle was resected. Shoulder exercises were begun even before the sutures were removed. Three weeks after operation there was no evidence of deformity or disability, and all symptoms had disappeared. The soldier cheerfully returned to full duty. This case is an instance of failure to heal under conservative therapy, even when conditions are ideal.

Case 40.-This soldier sustained a fracture of the left clavicle, with separation of the acromioclavicular joint, produced by a direct blow over the shoulder in a jeep accident 10 months earlier in France. The fracture healed uneventfully and in good position, and the man was returned to combat. Nine and a half months after the accident, he began to experience pain in the left shoulder. It increased in severity and was aggravated by exercise in games and calisthenics. The acromioclavicular joint was painful to palpation but was not abnormally mobile. The clavicle on the injured side was more prominent than on the intact side. The limitation of abduction of the arm was 30 degrees. Roentgenograms (fig. 53) showed a well-healed fracture at the junction of the middle and outer thirds of the clavicle, with synostosis between the fracture site and the coracoid process and ossification of the conoid and trapezoid ligaments.

The operative findings clarified the pain and disability from which the patient had suffered. A mass of bone and scar tissue was found throughout the insertion of the subclavius muscle and in the area of the coracoclavicular ligaments. A bridge of bone was palpable between the coracoid process and the site of the old fracture. The distal third of the clavicle and the ossified coracoclavicular ligaments and regional scar tissue were


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removed en masse (fig. 53C), with a minimum of dissection. Physical therapy was begun as soon as the sutures had been removed. At the end of 3 months, when the patient had complete range of motion and was able to lift heavy weights, he was discharged to unrestricted duty.

Associated Fractures

Fractures were associated with the acromioclavicular dislocations in 11 cases in this series, there being 2 fractures in 1 instance (case 34, table 9). They were distributed as follows:

Four subchondral compression fractures of the clavicle (case 5, table 7; cases 35, 36, and 41, table 10).

Two avulsion fractures of the trapezoid ridge (cases 8 and 16, table 7).

A transverse fracture at the junction of the middle and outer thirds of the shaft of the clavicle (case 40, table 10).

A chip fracture of the acromial end of the inferior margin of the clavicle, in a partially overriding joint (case 9, table 7).

A chip fracture of the acromion process (case 4, table 7).

A fissure fracture of the acromion process (case 34, table 9). This patient also had a subchondral compression fracture of the clavicle.

Two avulsion fractures of the coracoid process (fig. 54, case 7; see also case 7, table 7; case 34, table 9), one of them in a patient who also had a subchondral compression fracture of the clavicle.

FIGURE 54 (case 7).-Roentgenogram showing avulsion fracture of medial aspect of right coracoid process sustained in jeep accident. This patient had a perfect cosmetic and functional result after immobilization for 6 weeks in author's splint.


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As in similar traumatic dislocations in other areas of the body, the ligaments presumably suffered less damage when their bony insertions were avulsed. In both avulsion fractures of the coracoid process (cases 7 and 34), healing was not influenced adversely, and conservative treatment produced good results, though ossification of the coracoclavicular ligaments occurred. The same course of events was observed in the single avulsion fracture of the inferior aspect of the clavicle. Abduction was painful in 3 of the 5 cases in which articular surfaces were involved in the injury, and all 5 patients had painful joints for varying periods of time, though in only 1 instance (case 5, table 7) did the pain persist and eventually require excision of the outer third of the clavicle.

Complications and Sequelae

As this series shows, pain and limitation of motion may follow any type of complete acromioclavicular dislocation, whether the patient is seen early or late and whether the treatment is good, bad, or lacking altogether. Symptoms and disability in this series were, as is usually the case, chiefly the result of the development of arthritis, calcification, and ossification of the soft parts, and synovitis and adhesions in the joint.

Arthritis.-Osteoarthritic changes (see fig. 47, case 27), calcifications of the capsular ligament (fig. 55, case 4), and loose osteocartilaginous bodies (see fig. 48, case 39) were found on the roentgenograms in 12 cases in this series.

FIGURE 55 (case 4).-Roentgenogram showing dislocation of right acromioclavicular joint 8 weeks after injury in motorcycle accident. Ossification of coracoclavicular ligaments and calcification of meniscus, with chip fracture of acromion, have been demonstrated by soft-tissue technique. Note nearly vertical joint line.


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Five of the twelve were treated by excision of the distal end of the clavicle. All had complete relief of symptoms within 3 weeks.

Atrophy or rarefaction of the acromial end of the clavicle was apparent in the roentgenograms in almost all the severe recent dislocations as well as in the cases seen late. If the dislocation remained reduced and normal function was resumed, the density of the bone gradually returned to normal.

So-called avascular necrosis or osteochondritis was observed in two cases (cases 35 and 36, table 10). In both, subchondral compression fractures were found at operation. Gross examination and roentgenologic examination of the excised specimens showed sclerosis of old bone, irregular areas of resorption, and new periosteal bone formation, typical of the process of healing in crushed spongiosa. Avascular necrosis is a complication which must be expected in a certain proportion of complete acromioclavicular dislocations, especially in severe cases, whether or not reduction is accomplished.

Only 7 of the 12 patients who presented these various changes had genuine pain, and only 5 of these, as already mentioned, had pain severe enough to require operation. There seems logic, therefore, in the position of some observers that the phenomena are not necessarily evidence of traumatic arthritis.

Calcification and ossification of soft parts-Calcification of the conoid and trapezoid ligaments was demonstrated by roentgenograms in 18 cases (figs. 56, 57, and 58). (See figs. 47, 48, 53, and 55 for further examples.)

FIGURE 56 (case 19).-Roentgenogram showing dislocation of left acromioclavicular joint, 7 weeks after fall from motorcycle. Note calcification under clavicle, which had been evident since 3 weeks after injury, but at that time did now show up clearly enough for reproduction.


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These deposits first appeared within 3 or 4 weeks after injury and increased in density and extent during the several months that healing was in progress. They varied widely in their final size. In some instances, the deposit was a mere fleck, which could be observed only in oblique roentgenograms made by a special soft-tissue technique. In other instances, it took the form of massive ossification of the coracoclavicular ligaments and synostosis of the clavicle and scapula. Gross and roentgenologic examination of excised specimens containing new bone showed that in some instances the calcification appeared as an outgrowth from the periosteum of the clavicle or the coracoid process, while in other specimens it was a completely detached body.

Until actual fusion of the clavicle and scapula occurred, these deposits, judging by the patients' complaints and the physical findings, were not of clinical significance. When the synostosis was nearly complete (see case 24 in table 8 and fig. 57), range of motion of the coracoclavicular syndesmosis was diminished, and the effect on function was that of ankylosis of the acromioclavicular joint. In the case just mentioned, abduction beyond 90 degrees was painful and limited, although subluxation was only moderate. Both symptoms and deformity were relieved by excision of the outer end of the clavicle.

FIGURE 57 (case 24).-Roentgenogram showing dislocation of left acromioclavicular joint 9 months after injury sustained when jeep rolled down embankment under enemy fire. Note coracoclavicular synostosis, which was associated with moderate pain and inability to abduct arm beyond 80 degrees.


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FIGURE 58 (case 26).-Roentgenogram showing dislocation of  right acromioclavicular joint 10 weeks after automobile accident caused by artillery blast. Note coracoclavicular synostosis (indicated by arrow) which was associated with slight pain and limitation of abduction.

Synovitis and joint adhesions.-When vague pains and uncomfortable crepitations are present in complete dislocations of the acromioclavicular joint in the absence of demonstrable roentgenologic changes in the bone or the joint, it may be assumed that synovitis and articular adhesions are present. Swelling over the acromioclavicular articulation is sometimes observed in such cases. The patients may complain of instability with extreme motions of the shoulder, though this complaint usually disappears as time passes. These complications, as has already been noted, may occur whether or not the dislocation has been successfully reduced.

In the only case (case 6, tables 7 and 10) in this series in which these particular complications were evident, conservative treatment with the author's splint had apparently been successful for a year after treatment. Then the man, who was a stevedore, began to be incapacitated for his duties. When the outer end of the clavicle was eventually resected, the joint cavity was found obliterated by intra-articular fibrous connective tissue, calcified capsular ligament, and torn meniscus.

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