Shoulder Pain

Abstract

Introduction Shoulder pain following trauma is a common chief complaint of competitive athletes in the training room and office setting. Acute shoulder injury occurs regularly in high-impact collision sports such as ice hockey and constitutes about 10% of youth tournament injuries [1]. Differentiating acute traumatic injury from chronic overuse injury is important, and an accurate diagnosis is the key to rehabilitation and timely return to competition. Case Report History A 20-year-old Division III collegiate hockey player sustained a game-ending right shoulder injury midway through the second period from a body check into the boards. He described the impact to his shoulder as a high-energy collision into the boards and acrylic glass protective risers at a 90° angle. He felt immediate pain in his shoulder and had to leave the ice. Physical examination His initial examination was in the rink training room. He held his right arm tightly adducted against his body with his left arm holding his injured arm firmly against his abdomen. On inspection, there was neither an obvious bony deformity nor a step off at the acromioclavicular (AC) joint. There was pain to palpation at the AC joint and just distal to the joint on the acromion process. Pain was also pronounced over the deltoid muscle, the supraspinatus muscle, the trapezius muscle, and the boney spine of the scapula. Any movement of the scapula, including cross-body adduction, elicited intense pain in the shoulder area. Testing of the rotator cuff muscle function was difficult due to the player's level of pain but there did not appear to be any muscle or tendon disruption. He was given a sling for comfort and support while he watched the rest of the game. He was instructed to report to the local emergency department after the game for shoulder radiographs to rule out a fracture. En route to the facility, his father arranged for him to see his family physician. Diagnostic imaging Anteroposterior (AP) and trans-scapular views, of the right shoulder were taken at his family physicians office. The axillary lateral view could not be done due to discomfort with the required positioning. The initial radiograph showed a slight widening of the right AC joint with no widening of the coracoclavicular space. There was no obvious fracture on the plain films (see Fig. 1, which shows an injury similar to that of the patient in this case, who gave permission for use of his case but not his radiographs).Figure 1: Undisplaced fracture of the glenoid neck (arrow).Working diagnosis and care plan Given the mechanism of injury, the results of physical examination, and radiographic findings, the player was diagnosed with a type II AC sprain injury. He was discharged from the physician's office with instructions to use the sling for relative rest, support, and pain control; to ice the injured area intermittently for pain control and to reduce swelling; to use nonsteroidal anti-inflammatory medications for pain; and to follow-up with the team athletic trainer for rehabilitation and early mobilization. The player stayed in a sling for 2 weeks and was hesitant to initiate range of motion activity because of continued pain with abduction. There was no joint instability on repeated examinations and immobilization for the type II AC injury was continued. After 2 more weeks of relative immobilization and only mild improvement, repeat radiographs with comparison AP films were taken. On this set of films, it was evident the right and left AC joints were equally widened. An area of hypertrophic bone callous was noted along the scapular neck (Fig. 2 shows a similar injury). The previous films of the shoulder were reviewed and a nondisplaced fracture was noted in the same area as the area of new bone formation.Figure 2: Callous formation in glenoid neck fracture about 1 month after injury.Outcome The player remained in a sling and was slowly able to increase his activity and comfortable range of motion. He added light weight lifting at 4 weeks and was able to return to activities of daily living. He did not heal in time to return to regular season play or the Division III playoffs. He plans to return for next season. Discussion Acute traumatic shoulder injuries are common in contact sports. The severity of the injury can often be determined by history and physical examination. On the sideline or in the training room, a definitive diagnosis may not be determined if imaging is necessary to rule out a fracture. Patients younger than 30 years of age presenting with acute traumatic shoulder injury most commonly have glenohumeral dislocations, clavicle fractures, or AC joint sprains [1]. A shoulder separation is almost always the result of direct trauma to the shoulder. The two most common descriptions of mechanism for a shoulder separation are either a direct blow to the shoulder (football, hockey, mountain biking) or a fall on the outstretched hand (roller-blading, bicycling). The generally accepted classification is a modification of the Allman scale by Rockwood, describing six types of injury [2]. In type II injuries, as initially suspected in this case, there is partial rupture of the AC ligament and joint capsule with a sprained but intact coracoclavicular ligament. These injuries are usually treated with cryotherapy, pain medication, and early range of motion. Functional recovery may take up to 6 weeks and it probably takes 12 weeks for full healing of the ligaments. The athlete may return to participation when pain free with full range of motion and strength equal to the uninjured contralateral side is achieved. The AC joint can be padded for extra protection if needed. Surgery is rarely indicated in this injury. Fractures of the scapula are far less common and receive little attention because they account for less than 1% of all fractures [3,4]. The low incidence is likely due to the relative protection of the bony structure by the rib cage and surrounding musculature. The scapula serves as an attachment site for 18 muscles, linking it to the spine, upper extremity, and thorax [5], and is critical to scapulothoracic motion and shoulder function. Typically, scapula fractures result from high-impact trauma and direct forces. Indirect mechanisms are also possible, albeit much less common, such as a fall on an outstretched arm. A fall on the outstretched are drives the humeral head directly into the glenoid cavity [6]. Scapula fractures are often associated with life-threatening injuries because the force required to fracture the scapula commonly causes associated rib fractures and, on occasion, pneumothoracies. Concurrent head injuries are also common. Rowe's case series [7] reported that 71% of the patients had associated injuries: 45% sustained fractures of other bones, including the spine, sternum, and ribs; 3% sustained a pneumothorax; 4% sustained brachial plexus injuries; and 19% sustained other shoulder girdle dislocations [7,8]. In reviewing radiographs of the scapula in adolescent and young adult athletes, it is important to note that many of the scapula apophyses do not fuse until 23 to 25 years of age. Because of this, contralateral comparison films are helpful to distinguish a scapular fracture from an unfused apophysis [9]. A CT scan of the scapula can pick up most undetected scapular fractures and can be considered if fracture is suspected but not documented with plain films. Most scapula fractures can be managed with closed, conservative treatment. Surgical management is reserved for only significantly displaced fractures that involve more than 25% of the glenoid articular surface [10] or greater than 1 cm medial displacement of the glenoid neck [6]. The musculature around the scapula makes nonunion rare. To avoid shoulder stiffness, most physicians recommend sling, ice, and supportive measures until the initial pain subsides. Early mobilization and gradual introduction of strength training is also supported [8]. Conclusions Common things are common. This is a mantra heard throughout the field of medicine. AC injury was a logical initial diagnosis given the athlete's mechanism of injury as well as physical and radiographic findings. However, closer attention to imaging detail would have alleviated a delayed diagnosis in this player, although it would not have changed his outcome or time course of management. An initial comparison radiograph, looking at both AC joints, would have shown equal spacing between the two. With that information earlier discovery of the scapular fracture would have been likely. When the athlete varies from the normal recovery course and is compliant with the treatment plan, reassessment is necessary to confirm or refute the initial diagnosis. Fortunately in this case, the treatment for both conditions is quite similar. Immobilization until initial pain subsides then slow return to activity. This case illustrates the importance of thorough examination and history while still looking for some zebras along the way. Acknowledgments Thank you to Justin Byers, ATC, for assistance with the case history, and John Knoedler, MD, for allowing us to use his teaching radiographs.