of the Shoulder and Humeral Shaft

Fig. 18.1

Anatomy of the superior shoulder suspensory ring

Treatment of this injury is controversial, but fractures with minimal displacement, <5 mm in the scapula and up to 10 mm in the clavicle, will reportedly do well with nonoperative care [3, 4]. Fractures with greater displacement should be considered for surgical stabilization. Clavicle fixation with a plate and screws is often sufficient to reduce the glenoid displacement and stabilize the ring. It has been suggested that both fractures in the ring need internal fixation, but each case must be evaluated individually [4].

The most severe form is the scapulothoracic dissociation, in which the entire scapula–humerus–clavicle complex is “avulsed” from the chest wall, either through disruption of the bone or soft tissues. This requires high energy, and the clinical diagnosis is not always easy but is important to recognize, as there is a high incidence of associated neurovascular injuries. Close monitoring for vascular complications is necessary. Unless arterial repair is needed, the treatment is conservative.

Rotator Cuff Tendon Injuries

The rotator cuff tendon, made up of the conjoined tendons of the supraspinatus, infraspinatus, and teres major muscles, engulfs the humeral head and is responsible for the smooth abduction of the glenohumeral joint. Disruption of the tendon may occur from acute trauma in younger people or from a degenerative tear in people over 60 years of age. Acute tears associated with major trauma to the shoulder area may need surgical repair. Chronic degenerative tears are preceded by pain with shoulder abduction and tenderness beneath the acromion. Begin treatment with rest, range of motion exercise, muscle strengthening, and anti-inflammatory medication.

Glenohumeral Dislocations

Anterior Dislocations

Anterior dislocations outnumber posterior dislocations by about 8:1, and the two can be distinguished by both history and physical exam. The initial anterior dislocation usually follows trauma with forced abduction and external rotation of the arm [5]. The patient maintains his arm in slight abduction and external rotation; internal rotation is blocked, and there is a “squared-off” appearance to the shoulder. Anterior shoulder dislocations may have associated axillary nerve or brachial plexus injuries, making an initial neurovascular exam necessary.

Appropriate X-ray views including a scapular AP, trans-scapular lateral (or Y), and axillary lateral (Fig. 18.2) should be done to confirm the diagnosis and rule out associated fractures before closed reduction. The humeral head is seen anterior to the “Mercedes Benz sign” in the trans-scapular view (video of basic X-ray anatomy of the shoulder: http://www.youtube.com/watch?v=h-cA9hYp0Ok) (http://www.youtube.com/watch?v=GtwONEsPLjc).

../images/270913_2_En_18_Chapter/270913_2_En_18_Fig2_HTML.png — Fig. 18.2

(a) Illustration of how to take axillary lateral view of shoulder with minimal shoulder abduction. The patient’s head and neck are bent away from the X-ray plate, the elbow is flexed, and the injured extremity is stabilized by holding an IV stand. (b) X-ray shows coracoid process, the acromium overlying the humeral head and true lateral views of both humeral head and glenoid

Posterior Dislocations

Posterior dislocations result from trauma in about two-thirds of cases, but the remainder occurs during seizures or electrical injuries. Since the dislocation is directly posterior, the shoulder deformity is not as obvious as with anterior dislocation and is often missed. The classic findings are shoulder pain with loss of external rotation and fullness over the coracoid. X-rays often appear normal in the anterior–posterior view, making axillary or scapular lateral views necessary. Closed reduction for acute posterior dislocations is usually successful. The “lightbulb” sign seen on the anterior–posterior view of a posterior dislocation may be helpful (https://www.imageinterpretation.co.uk/shoulder.php#Post_dislocation).

Closed reduction within <3 weeks for both anterior and posterior dislocations is usually successful. If closed reduction is not possible, the two remaining options are open reduction and early rehabilitation allowing the shoulder to remain dislocated. While many surgical approaches have been described [6, 7], all report difficulty re-placing the humeral head into the glenoid and having it stay. Some have used pins through the head into the glenoid to secure the reduction. Most report limited range of motion post-op, while injury to the axillary nerve is common. Results are worse the longer the shoulder has been dislocated.

Fractures associated with shoulder dislocations commonly involve the glenoid rim, impression fractures of the humeral head (Hill–Sachs and reverse Hill–Sachs lesions), the greater tuberosity, the humeral neck, and shear injuries of the humeral head. Glenoid and impression fractures of the head are associated with recurrent dislocations but rarely need immediate treatment. Tuberosity fractures usually reduce when the dislocation is reduced and will heal spontaneously. If the residual displacement is more than 3–4 mm, they may cause impingement symptoms and need surgical correction [5]. Shoulder dislocations associated with humeral neck and articular surface fractures are usually treated initially with attempted closed reduction. If successful the fractures are treated individually as described in the next section. If unsuccessful the options are the same as for isolated dislocations.

Chronic Dislocations

Shoulder dislocations presenting late are common in low resource environments and more challenging. The usual definition of “acute” is within 3 weeks of injury [5]. Dislocations seen in this time period will often reduce with closed treatment, although as time goes on more muscle relaxation might be needed, including general anesthesia. A closed reduction can be successful up to 4 weeks, but be gentle and take increased care to avoid fracturing the humerus, especially avoid forced rotation (Fig. 18.3).

../images/270913_2_En_18_Chapter/270913_2_En_18_Fig3_HTML.jpg — Fig. 18.3

(a) This farmer fell out of a tree in his orchard 6 weeks before and sustained right and left anterior shoulder dislocations. (b) Shoulder X-rays. He came to the orthopedic clinic because he was having some difficulty doing his farm work due to limited motion, and traditional therapy had not improved the function. He had no pain and therefore no surgery was offered. (c) He also had a complex dislocation of his left index MP 8 years previously and had no complaints regarding it. (Courtesy of Dr. Sam Baker)

Advice from surgeons in developing countries suggests that beyond 3 months, open reduction is extremely difficult and should not be attempted. It is better to begin physical therapy for range of motion and muscle strengthening. The patient will not regain full abduction or forward elevation but will have satisfactory function otherwise as the case illustrates (Box 18.1).

Box 18.1 Case Illustration

A 26-year-old male came to the orthopedic clinic with a chief complaint of inability to use his right upper extremity to reach or perform activities at or above shoulder level. He had injured his shoulder 7 years before and was told later that it was dislocated, but he had not been treated. The right shoulder had an active range of motion of 30° abduction, 40° forward elevation, and full internal and external rotation. This appeared to be performed with minimal discomfort. Elbow and hand function were normal. X-rays showed an anterior glenohumeral dislocation. Although he wanted to have improved “use” of his shoulder, he was employed and stated that pain was not a problem. The clinic staff felt that no further treatment was indicated.

If closed reduction is not possible, the two remaining options are open reduction and early rehabilitation allowing the shoulder to remain dislocated. While many surgical approaches have been described [6, 7], all report difficulty replacing the humeral head into the glenoid and having it stay. Some have used pins through the head into the glenoid to secure the reduction. Most report limited range of motion post-op, while injury to the axillary nerve is common. Results are worse the longer the shoulder has been dislocated.

We advise against simple humeral head resection as a flail shoulder is not functional. Patients with a chronically displaced shoulder usually adapt fairly well from a functional point of view, but if residual pain is truly disabling, two surgical options remain. Arthrodesis is technically challenging if the displacement is long standing. The second option, “shoulder Girdlestone” or Laurence Jones procedure, is a trade-off between pain and weakness/instability but may allow better function (see Chap. 41) (Video of one surgical technique for treatment of chronic dislocation of shoulder for which the authors have no personal experience https://www.vumedi.com/video/surgical-reduction-of-chronic-shoulder-dislocation/).

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