Acute Shoulder Injuries


Ovid: Manual of Orthopaedics

Editors: Swiontkowski, Marc F.; Stovitz, Steven D.
Title: Manual of Orthopaedics, 6th Edition
> Table of Contents > 15 – Acute Shoulder Injuries

15
Acute Shoulder Injuries
I. General Principles
  • Anatomy. The
    ability to place your hand functionally above your head, behind your
    back, and at all points in between is largely dependent on the
    shoulder’s extreme range of motion. This degree of flexibility defines
    it as an unconstrained joint. The stability can be divided into static
    and dynamic constraints. Statically, there is a small flat glenoid
    surface articulating with the large humeral head. The depth of the
    glenoid cavity is augmented by the labrum, which also serves as the
    anchor point for the capsular ligaments to the glenoid and the origin
    of the biceps. The glenoid articulation and the labrum in themselves
    have little constraint to the glenoid humeral joint. The ligaments
    serve as additional static restraints at the extreme range of motion.
    The dynamic component of stability for the glenohumeral joint comes
    from the surrounding musculature. The rotator cuff muscles
    (supraspinatus, infraspinatus, and teres minor) plus the subscapularis
    and the long head of the biceps are very important dynamic stabilizers (3).
    Another degree of dynamic stability comes through the scapulothoracic
    articulation which provides one third of the total active motion of the
    shoulder girdle. The position of the scapula is the foundation off
    which the glenohumeral joint functions. The periscapular muscles are
    extremely important in positioning the glenoid cavity correctly as well
    as providing a stable platform from which the glenohumeral joint
    functions. The neurovascular bundle lies directly anterior and inferior
    to the glenohumeral joint, which accounts for the frequency of
    neurovascular injuries, especially with anterior dislocations that are
    associated with shoulder trauma.
  • Differential diagnosis.
    The majority of patients presenting with acute shoulder pain are
    suffering from either a dislocation, fracture, or muscle rupture.
    Still, it is important to consider that a variety of other entities may
    cause acute shoulder pain including:
    • Cervical disc disease (C5 nerve root)
    • Thoracic outlet
    • Brachial neuritis
    • Diaphragmatic irritation
    • Pleural irritation
    • Superior sulcus tumors (Pancoast tumor or metastatic disease)
    • Cholecystitis (right shoulder)
    • Cardiac symptoms (typically left shoulder)
  • The majority of shoulder disorders can be
    managed and produce a good outcome by nonsurgical treatment which
    centers around physical therapy to regain the strength of muscles
    around the joint and range-of-motion exercises to maintain flexibility.
II. Shoulder Dislocations
  • Classification.
    Approximately 50% of all major joint dislocations involve the
    glenohumeral joint. Dislocations are commonly classified by direction
    (anterior, inferior, posterior, or multidirectional), onset (acute,
    recurrent, chronic), and by etiology (traumatic, minimally traumatic,
    atraumatic, microanterior instability). Anterior dislocations are the
    most common. Dislocations that occur in patients younger than 20 years
    old typically involve an avulsion of the ligaments and labrum from the
    glenoid. Dislocations that occur in patients older than 30 years of age
    tend to involve interligamentous tears. Dislocations in patients older
    than 50

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    are
    often associated with rotator cuff tears and/or greater tuberosity
    fractures. The older the patient, the lower the rate of recurrence of
    dislocations, but older patients also have a higher rate of
    posttraumatic shoulder stiffness (13).

  • Anterior dislocations
    • Mechanism of injury.
      The injury usually results from a traumatic event in which the position
      of the arm is in an externally rotated and forward-flexed or an
      abducted position.
      • In patients younger than 20 years of age,
        the anterior capsule and labrum are avulsed from the glenoid,
        occasionally with a small fragment of bone (Bankart lesion). The
        humeral head dislocates anterior to the glenoid fossa and under the
        coracoid process. A compression fracture may occur on the
        posterolateral humeral head (Hill-Sachs lesion) from impaction of the
        head on the anterior edge of the glenoid (2).
      • In patients older than 40 years of age,
        intrasubstance failure of the anterior capsule and an acute rotator
        cuff tear can occur. An acute rotator cuff tear can be difficult to
        repair if not detected within the first 6 weeks postinjury.
      • Recent basic science studies have shown
        that sectioning of the anterior capsule alone does not cause gross
        anterior instability. Damage to the posterior or superior capsule must
        also occur for a complete anterior dislocation to occur.
    • Examination.
      Individuals with an acute dislocation hold their arm in an adducted
      position. There is a loss of symmetry of their shoulders and the
      humeral head can be palpated anterior and inferior to the coracoid
      process. Any attempt at range of motion of the shoulder is extremely
      painful. A thorough neurovascular check of the upper extremity is
      necessary before any attempt is made to reduce the dislocation.
      Attention to checking the sensory function of the axillary nerve over
      the lateral aspect of the shoulder is important.
    • Roentgenograms. In all patients with a suspected initial dislocation of the shoulder, a standard trauma series should be obtained (10).
      This series includes an anteroposterior and a transscapular lateral
      (“Y”) view. If the presence and direction of the dislocation are not
      clearly evident, an axillary view is obtained. This view is difficult
      to obtain and painful for the patient; it may require physician
      assistance to position the patient’s shoulder. Any associated
      tuberosity fractures or epiphyseal injuries should be clearly
      visualized.
    • Treatment of the first dislocation
      • Reduction without general anesthesia.
        Prompt reduction of the dislocation provides a great deal of pain
        relief. To achieve a gentle and pain-free reduction, muscle relaxation
        and pain relief are required. Multiple methods of reduction have been
        described, but the author prefers one of the following methods:
        • Prone reduction under lidocaine block (14).
          The patient is allowed to remain sitting on the examination table, and
          the posterior aspect of the shoulder is sterilely prepped. Ten to 20 mL
          of 1% lidocaine are injected into the glenohumeral joint posteriorly.
          The patient is then placed prone on the examination table with the
          involved arm and shoulder hanging in a dependent position over the edge
          of the table. A 10-lb weight is suspended from the patient’s wrist.
          After 10 to 15 minutes, good analgesia and relaxation are present and
          the shoulder can be reduced by elevation and forward rotation of the
          medial border of the scapula.
        • Reduction by traction.
          If the first method fails, the patient is repositioned supine and
          additional intravenous (IV) sedation is administered. A sheet is placed
          around the patient centered in the axillary region. An assistant holds
          the two ends of the sheet above the patient and provides
          countertraction while the physician grasps the forearm of the involved
          shoulder and gently pulls in a line of 30 degrees of abduction and 20
          to 30 degrees of forward flexion. Sustained traction for 5 minutes may
          be necessary. Vigorous and forceful attempts

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          at reduction are to be avoided since this may result in a fracture, especially in older osteopenic patients.

      • Reduction under anesthesia.
        If the aforementioned methods fail or if a significant fracture is
        present, a reduction under general anesthetic with complete muscle
        relaxation is indicated. The shoulder typically reduces easily with
        little risk of further damage to the glenohumeral joint or its
        surrounding structures.
    • Postreduction treatment. The length of immobilization has no effect on the incidence of redislocations (12).
      The shoulder should be immobilized for a brief period as needed for
      pain control after a dislocation or subluxation episode. A
      range-of-motion and rotator cuff strengthening program is initiated
      early, but the extremes of range of motion for forward flexion or
      external rotation are avoided. Patients are allowed to return to sports
      and other activities when the shoulder has good strength and minimal
      apprehension in an abducted, externally rotated position (1, 6). A general rule is the younger the patient, the higher the possibility of recurrent instability (9).
    • Recurrent dislocations or subluxations. If necessary, the shoulder is reduced as in B.4
      (above). Occasionally, if witnessed “on the field” and the evaluation
      suggests a recurrent dislocation without fracture, then an attempt for
      reduction can be made prior to radiographic imaging. If anesthesia is
      not available, reduction is the best pain relief. A postreduction,
      physical therapy program is prescribed as in B.5
      (above). Recurrent instability episodes may be painful and disabling.
      Many different types of surgical repairs have been described (12,15,16,19). The author prefers either an open or arthroscopic Bankart repair or capsular shift reconstruction (15,17).
      The open type of repair has been associated with success rates of 97%
      with few significant complications. Arthroscopically assisted repairs
      are technically possible but have not yet achieved success rates
      comparable to open capsular repairs, especially in athletes in high
      contact sports.
    • Complications
      • Damage to the nerves
        originating with the brachial plexus occurs in 5% to 14% of shoulder
        dislocations. The axillary nerve and musculocutaneous nerve are most
        commonly injured. Most injuries are a neuropraxia, and a full recovery
        is typical. The same is true with postoperative neurologic injuries.
        While the injured nerve is recovering, it is important not to allow any
        secondary contractures of the joint to develop.
      • Rotator cuff tears
        are common in patients older than 40 years with an anterior
        dislocation. If good range of motion and strength have not returned
        within 3 to 4 weeks after the injury, visualization of the rotator cuff
        with magnetic resonance imaging (MRI) or ultrasound is indicated.
  • Posterior dislocations
    • Mechanism of injury.
      Posterior instability results from a fall on an adducted and forward
      flexed arm, which drives the head of the humerus posterior to the
      glenoid fossa. A compression fracture of the anterolateral aspect of
      the humeral head may develop (reverse Hill-Sachs lesion). In younger
      individuals, an avulsion of the posterior labrum with a small fragment
      of the posterior glenoid rim (reverse Bankart lesion) may occur.
      Seizures or electrocution are other mechanisms that often produce
      posterior instability (7).
    • Examination.
      An obvious clinical deformity is typically not present and the patient
      may be complaining of only minimal symptoms. Many posterior
      dislocations are not diagnosed and reduced in the emergency department.
      External rotation of the shoulder is limited and painful, and is the
      hallmark of a posterior shoulder dislocation.
    • Roentgenograms.
      Anteroposterior views often are normal and misleading except that the
      arm is positioned in a markedly internally rotated position, which
      produces a “light bulb sign” with the proximal humerus. A transscapular
      “Y” view and an axillary view show the posterior position of the
      humeral head.
    • P.226


    • Treatments.
      Muscle relaxation via IV sedation is recommended. Reductions can
      usually be obtained by gentle traction on the arm with an additional
      anterior and laterally directed force applied to the posterior aspect
      of the humeral head. Postreduction treatment is similar to that for
      anterior dislocation (B.5.)
      except internal rotation and adduction extremes are avoided. If the
      shoulder dislocates immediately after being reduced, the arm should be
      braced in a neutral rotation and an abducted position for 4 weeks to
      maintain stability. Posterior dislocations that result from seizures or
      electrocutions may have large or reverse Hill-Sachs lesions that lead
      to further instability episodes.
    • Recurrent dislocations
      that occur as a result of traumatic events and have evidence of
      ligament damage may be treated with a reverse capsular shift. Many
      patients with posterior instability do not have a history of a
      significant traumatic event that initiated the instability and may be
      able to voluntarily dislocate or sublux
      their shoulder. These patients have poor operative results and should
      undergo treatment with physical therapy and activity or lifestyle
      restrictions (5).
  • Multidirectional instability (MDI)
    • Mechanism of injury.
      MDI is diagnosed when there is clinical evidence that the shoulder is
      unstable in two or more directions. There is often no history of
      significant trauma and the patient may be able to voluntarily dislocate
      the shoulder.
    • Examination.
      The typical patient is a “double-jointed” adolescent female. A sulcus
      sign is present and the patient is apprehensive with the arm in
      positions that stress both the anterior and posterior capsule.
    • Roentgenograms.
      Often, radiographs are normal. The presence of a Hill-Sachs or a
      reverse Hill-Sachs lesion is detected on a Stryker notch view but often
      is not in fact present.
    • Treatment. Nonoperative treatment is strongly advised because operative management has a high failure rate (18).
      A procedure using thermal energy to arthroscopically “shrink” the
      redundant capsule has not proven successful and has been associated
      with significant complications including capsular necrosis and
      chondrolysis (8).
  • Inferior dislocations.
    Inferior dislocations are rare. The patient’s arm is locked in an
    overhead position. Reduction is obtained by IV sedation and relaxation.
    The arm is then reduced with lateral distraction while the arm is
    brought out of an abducted position.
III. Acute Tears Of The Rotator Cuff
  • Mechanism of injury.
    Acute tears of the rotator cuff are rare and occur mainly in
    individuals younger than 40 years old who have a history of significant
    trauma. Attritional tears of the rotator cuff are more common and occur
    in older individuals (see Chap. 16).
  • Examination (see Chap. 16).
  • Roentgenograms.
    Damage to the glenohumeral joint, including the greater tuberosity, is
    best assessed on an anteroposterior view, obtained with the arm in 30
    degrees of external rotation. An outlet view and an axillary view
    should also be obtained. Young individuals who are suspected of having
    a rotator cuff tear on history or examination should undergo an MRI
    scan or an ultrasound evaluation to assess the status of their rotator
    cuff.
  • Treatment. In
    young or active patients with a true acute rotator cuff tear, early
    (within 3 months) operative repair is indicated. Early repair is also
    indicated in those cases associated with a displaced avulsion fracture
    of the greater tuberosity (4). Displacement of a greater tuberosity fragment by more than 1 cm correlates highly with an acute rotator cuff tear.
IV. Ruptures of the long head of the biceps brachii
  • Mechanism of injury.
    Injuries of the long head of the biceps (LHB) tendon may occur with
    forceful elbow flexion or hand supination. Eighty percent of the cases
    are associated with ongoing rotator cuff problems and shoulder
    impingement syndrome. Steroid use for body conditioning is an
    increasingly common etiology.
  • P.227


  • Examination.
    A visible asymmetry of the injured versus noninjured upper arm is
    evident when the patient is asked to “make a biceps” muscle. This
    deformity is called a “Popeye” sign.
  • Treatment.
    Ruptures of the LHB tendon are treated nonoperatively. The indications
    for repair are mainly cosmetic in nature because little functional
    disability results. In patients with evidence of impingement syndrome,
    an appropriate workup of the rotator cuff is indicated, particularly in
    active patients or those under 60 years of age.
V. Rupture of The Pectoralis Major
The pectoralis major muscle or tendon typically ruptures
with a bench press lift, a seated fly lift, or a similar functional
maneuver. The patient has pain and an ecchymosis in the anterior
shoulder. On examination, there is a loss or defect in the anterior
axillary line. Treatment is usually symptomatic except in the heavy
laborer or athlete in whom early operative repair is indicated.
Ruptures at the muscle tendon junction are difficult to repair and have
a worse outcome than tears at the bone/tendon or tendon/tendon
interface. A preoperative MRI scan is indicated in those individuals
for whom operative repair is being considered to determine at what
level the defect has occurred.
VI. Scapular Fractures
These injuries are frequently treated nonoperatively,
with early range of motion of the shoulder girdle. Displaced fractures
involving greater than 25% percent of the articular surface of the
glenoid or glenoid neck fractures with medial displacement are
generally treated operatively to reduce the risk of glenohumeral
instability or arthritis (11).
References
1. Arciero
RA, Wheeler JH, Ryan JB, et al. Arthroscopic bankart repair vs.
non-operative treatment for acute, initial, anterior shoulder
dislocations. Am J Sports Med 1994;22:589–594.
2. Baker CL, Uribe JW, Whitman C. Arthroscopic evaluation of acute initial anterior shoulder dislocations. Am J Sports Med 1990;28:25–28.
3. Bassett RW, Browne AO, Morrey BF, et al. Glenohumeral muscle force and moment mechanics in a position of shoulder instability. J Biomech 1990;23:405–415.
4. Bassett RW, Cofield RH. Acute tears of the rotator cuff: the timing of surgical repair. Clin Orthop 1983;175:18–24.
5. Bigliani
LU, Pollock RG, McIlveen SJ, et al. Shift of the posteroinferior aspect
of the capsule for recurrent posterior glenohumeral instability. J Bone Joint Surg (Am) 1995;77:1011–1020.
6. Bottoni
CR, Wilckens JH, DeBeradino TM, et al. A prospective, randomized
evaluation of arthroscopic stabilization versus nonoperative treatment
in patients with acute, traumatic, first-time shoulder dislocations. Am J Sports Med 2002;30: 576–580.
7. Buhler M, Gerber C. Shoulder instability related to epileptic seizures. J Shoulder Elbow Surg 2002;11:339–344.
8. Burkhead WZ, Rockwood CA. Treatment of instability of the shoulder with an exercise program. J Bone Joint Surg (Am) 1992;74:890–896.
9. Deitch J, Mehlman CT, Obbehat A, et al. Traumatic anterior shoulder dislocation in adolescents. Am J Sports Med 2003;31:758–763.

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10. Engebretsen L, Craig EV. Radiologic features of shoulder instability. Clin Orthop 1993;291:29–44.
11. Hardegger FH, Simpson L, Weber BG. The operative treatment of scapular fractures. J Bone Joint Surg (Br) 1984;66:725–731.
12. Hovelius L. Anterior dislocation of the shoulder in teenagers and young adults: five-year prognosis. J Bone Joint Surg (Am) 1987;69:393–399.
13. Johnson
JR, Bayley JI. Early complications of acute anterior dislocation of the
shoulder in the middle-aged and elderly patient. Injury 1982;13:431–434.
14. Lippitt
SB, Kennedy JP, Thompson TR. Intraarticular lidocaine verses
intravenous analgesia in the reduction of dislocated shoulders. Orthop Trans 1992;16:230.
15. Morgan CD, Bodenstab AB. Arthroscopic bankart suture repair: technique and early results. Arthroscopy 1987;3:111–122.
16. Morrey
BF, James JM. Recurrent anterior dislocation of the shoulder: long-term
follow up of the putti-platt and bankart procedures. J Bone Joint Surg (Am) 1976;58:252–256.
17. Rowe CR, Pierce DS, Clark JG. Voluntary dislocation of the shoulder. J Bone Joint Surg (Am) 1973;55:445–460.
18. Rowe CR. Acute and recurrent dislocations of the shoulder. J Bone Joint Surg (Am) 1962;44:998–1008.
19. Torg
JS, Balduini FC, Bonci C, et al. A modified Bristow-Helfet-May
procedure for recurrent dislocation and subluxation of the shoulder:
report of two hundred and twelve cases. J Bone Joint Surg (Am) 1987;69:904–913.
Selected Historical Readings
Bankart ASB. Recurrent or habitual dislocation of the shoulder joint. BMJ 1923;2:1132.
Mosley HF. The basic lesions of recurrent anterior dislocation of the shoulder. Surg Clin North Am 1963;43:631.

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