DipMSK Revision Guide · Chapter 4 of 18

Shoulder Instability

Traumatic and atraumatic instability, labral pathology and the Stanmore polar types.

Syllabus: Shoulder Instability

Written by Dr David Palethorpe, MBBS, BSc (Hons), MRCGP · NHS GP PartnerReviewed 14 September 202618 min readChapter 4 of 18

Before you start

Try this first

Within two years, what is the recurrence risk for a male first dislocating at 15, 20 and 30?

Around 86% at 15, 72% at 20 and 41% at 30. The female figures are lower at every age — 54%, 40% and 19%. Almost 90% of recurrences happen inside those two years.

2 more warm-up questions in the full chapter.

What this chapter covers

  • 4.1Acute traumatic anterior dislocationArm abducted and externally rotated with a squared-off deltoid contour. Two views before reduction and two after, neurov…Preview below
  • 4.2Recurrent anterior instability and who needs stabilisingMembers
  • 4.3Labral and capsular pathology — what the arthrogram looks forMembers
  • 4.4Atraumatic instability and the Stanmore polar typesMembers
  • 4.5Posterior instability and the dislocation you will missMembers
  • —Referral, by timeframeRed flags below

Acute traumatic anterior dislocation

Core Lens — the takeaway

Arm abducted and externally rotated with a squared-off deltoid contour. Two views before reduction and two after, neurovascular status documented both times, and immobilisation for comfort only — beyond a week it does not reduce recurrence.

Recognise

  • Arm abducted and externally rotated, supported by the other hand, deltoid contour squared off.
  • Incidence 8.2–23.9 per 100,000 per year, male to female 2.55:1, almost half aged 15–29.
  • About 16% have a greater tuberosity fracture. Nerve injury is clinically apparent in 13.5%, two-thirds of it axillary.

The rest of this chapter is in the DipMSK guide

4 more topics, every section opened up, the recall questions and the guidance summaries — written and reviewed by practising UK doctors.

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Referral, by timeframe

Same day · Emergency
  • Unreduced dislocation, or any dislocation with vascular compromise
  • Any suspected acute posterior dislocation — same-day referral for reduction
  • A suspected septic joint
  • A nerve deficit with the dislocation — reduce immediately, then refer to a nerve injury service
  • A shoulder locked in internal rotation missed for days or weeks — discuss the same day

Also in the full chapter: Urgent · Routine.

← Chapter 3Shoulder Osteoarthritis

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