Acute Shoulder Pain in a Teenager After a Fall

PATIENT PROFILE:

A 16-year-old boy presents with severe left shoulder pain that began 20 minutes earlier when heslipped while walking down an incline and attempted to prevent a fall by grabbing a nearby structurewith his left hand. As his body went forward, the left shoulder was abducted and externallyrotated. The accident caused him immediate pain, and any subsequent movement of the injuredshoulder increases the pain. Previously, the patient was healthy.On examination, the left shoulder is minimally abducted and externally rotated. Instead ofits usual rounded contour, the shoulder has a square appearance. The acromion is very prominent,and below it an abnormal anterior fullness is evident. The patient holds his left arm with hisright hand to limit movement, and any attempt to move the upper extremity-especially internalrotation-is resisted because of pain. There is no sensory deficit in the shoulder area, and isometriccontraction of the deltoid muscle is normal.

WHAT WOULD YOU DO NOW?

A.

Order plain radiographs of the shoulder.

B.

Order an MRI scan of the shoulder.

C.

Attempt to reduce the dislocation immediately.

D.

Refer the patient for physical therapy

THE CONSULTANT'S CHOICE

This patient's injury is most likely an

anteriorshoulder dislocation.

The mechanism of injury is classic:forceful abduction and external rotation. The physicalfindings-squared shoulder, prominent acromion,and fullness below the acromion-are characteristic of ashoulder dislocation.It is best to reduce a dislocated shoulder as soon aspossible (choice C). Early reduction minimizes the discomfort,muscle spasm, and risk of further injury that accompanythis procedure.Delaying the reduction to obtain radiographs (choiceA) may make the reduction more difficult. Radiographsare important following reduction, both to ensure that thereduction was complete and to rule out the possibility of afracture. However, they are seldom obtained beforehand.Indications for a pre-reduction film include:

• Suspected growth plate fracture (in younger children).
• Presence of a neurologic deficit.

The most common neurologic deficit associatedwith shoulder dislocation is a motor deficit of the axillarynerve. Contraction of the deltoid is not possible when anaxillary nerve deficit is present. To test for deltoid function,place a hand on the patient's elbow and ask him orher to gently abduct the shoulder-while you resist the attempt to do so. If there is no nerve injury, you will feel thedeltoid contract. In this patient, deltoid function is intact.MRI (choice B) is more valuable in the evaluation ofchronic recurrent instability or when injury to the glenoidlabrum is suspected. It is rarely indicated in the acuteevaluation of a dislocation.Physical therapy (choice D) plays an important rolein therapy for a dislocated shoulder, but later in the courseof treatment.

METHODS FOR REDUCTION OF A DISLOCATED SHOULDER

There are multiple options for the reduction of a dislocatedshoulder. Older methods, such as placing a foot inthe axilla and exerting force, are unacceptable and canproduce further injury. The Stimson technique is most effectiveimmediately after an injury.

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This technique workswell when there is minimal swelling and spasm, and it isalmost always successful if performed soon after the dislocation.Have the patient lie prone on a flat raised surface,such as a table, with the injured limb hanging over theside

(Figure 1).

Tie a 3- to 5-lb weight (or whatever isavailable of an equivalent weight) to the arm.If more than an hour has passed since the injuryand/or if the patient has large, bulky shoulders, a narcoticsuch as morphine can help reduce muscle spasm andpain. However, reduction requires closer observation ofthe patient when narcotics have been given, and it is bestdone when an assistant can help monitor the patient.Other approaches appropriate in a more difficult reductioninclude techniques that involve use of an activecountertraction force. In one such technique, the patientsits in a chair and leans forward as an assistant places hisarms around the patient's torso to provide countertraction

(Figure 2).

Gentle traction is then applied to the injuredlimb; traction and countertraction are gradually increased until reduction is achieved. For more resistant reductions,sedation can be given.

WHAT WOULD YOU DO NOW?

A.

Prescribe 6 weeks of immobilization andextensive physical therapy.

B.

Prescribe 5 weeks of immobilization andextensive physical therapy

C.

Prescribe 4 weeks of immobilization andextensive physical therapy.

D.

Refer the patient to a surgeon for a primaryrepair of the torn structures..

THE CONSULTANT'S CHOICE

Some authorities believe that patients younger than20 years have a 70% to 85% chance of recurrent dislocation.Others think the risk is about 25%. In any event, thekey to preventing recurrence in this age group is to havepatients limit abduction for 6 weeks and do specificstrengthening exercises (choice A). Patients who returnto regular activity too early and/or who have not been diligentabout their rehabilitation routine are far more likelyto have another dislocation. The incidence of labral tearsis greater in patients who have repeated dislocations;these patients almost always require surgery.Thus, it is essential to advise patients younger than20 to wait 6 weeks before they return to any activities thatmay involve the stressful combination of shoulder abductionand external rotation. Contact sports-as well assome work-related activities-can produce this stress.Younger patients may feel capable of resuming participationafter 2 to 3 weeks, and they may seek clearance fromtheir primary care physician. However, laxity regardingthe 6-week rule increases the likelihood of repeated dislocationsin this age group.In older patients, less time is required for recovery.Garrick and Webb

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recommend 5 weeks (choice B) for20- to 30-year-olds, 4 weeks (choice C) for 30- to 40-yearolds,and 3 weeks for 40- to 50-year-olds. For patients olderthan 50 years, the shoulder can be mobilized as soon assymptoms permit.Surgery (choice D) can be considered as an initialapproach. However, most authorities recommend thatnonsurgical treatment be attempted first and that surgerybe reserved for those patients in whom conservative managementfails. Failure is usually established by the occurrenceof repeated subluxations.

Six months after he has completed his rehabilitation, thepatient begins to experience recurrent subluxation.

WHAT WOULD YOU DO NOW?

A.

Teach the patient how to self-reduce asubluxation.

B.

Obtain plain radiographs and an MRI scan.

C.

Recommend use of a harness that limitsabduction and external rotation.

D.

All of the above.

THE CONSULTANT'S CHOICE

The first 3 suggestions are all helpful in this setting(choice D). The patient can be taught to reduce a subluxationhimself (choice A) by the following method: while sittingin a chair or on a bench, simultaneously flex the knee90 on the same side as the subluxed shoulder and graspthe knee with both hands, then gradually extend the hip

(Figure 3).

At this point it is important to determine whether thesubluxations have damaged parts of the glenoid or thehumerus. Defects in the anteroinferior aspect of the glenoidrim are called Bankart lesions, and those in the posterolateralaspect of the humeral head are known as Hill-Sachs lesions. Both plain radiographs and MRI scans canreveal these lesions (choice B).Finally, if the patient participates in sports that posethe risk of repeated shoulder injury (such as football), youmay want to recommend that during play he wear a harnessthat limits abduction and external rotation (choiceC). Such a device can prevent recurrent dislocation.

Outcome of this case.

A radiograph of the patient'sshoulder revealed a Bankart lesion

(Figure 4).

The presenceof a Bankart lesion is an indication for surgical repair. The shoulder is unstable, and unless repaired surgicallyit will continue to sublux and cause further damageto the glenoid and the humeral head. The patient underwentsurgery; he also wore a harness to limit abductionwhen he played football this past season. He is now doingwell and has not had any recent subluxations.

References:

REFERENCES:

1.

Stimson LA. An easy method of reducing dislocations of the shoulder andhip.

Med Rec.

1900;57:356-357.

2.

Garrick JG, Webb DR.

Sports Injuries: Diagnosis and Management.

2nd ed.Philadelphia: WB Saunders Company; 1999:98-107.