Anterior Shoulder Dislocation

• Mecanisme : anteriorly directed force on the arm when the shoulder is abducted and externally rotated

• Xray is mandatory before any mobilisation to rule out associated fractures (In this case, open reduction should be done in the OR.

• Smooth closed reduction should be done (many techniques).

• Neurovascular exam should be done and noted before and after reduction.

• Xray is obtain to confirm reduction and to rule out any complication

• Immobilisation for 3 to 6 weeks (less for elderly).

• Physiotherapie is often necessary to regain complete shoulder mobility

• Recurrence rate correlates with age at first dislocation : 90% chance for recurrence in age <20: young patients should be alerted and even surgery proposed from the very first dislocation episode

• Rotator cuff may be torn, especially in elderly people (80% patients > 60 years of age) : patients who remain painful with limited range of motion should have MRI to evaluate the rotator cuff.

Recurrent dislocation is frequent, especially in very young patients, and thus patients develop chronic anterior shoulder instability.

Attention must be taken for generalized laxity : people with multidirectionnal instability should not be operated.

surgical interventions depend on ISIS score:

• Arthroscopic Bankart Repair is reserved for ISIS < 6 (and even <3). Otherwise, Latarjet procedure is performed with excellent results.

Posterior shoulder dislocation

• More than 50% of dislocation/instability can be missed

• Flexed, adducted, and internally rotated arm is a high-risk position

• Cause : trauma, seizure, electrical shock

• Always distinguish voluntary vs involuntary dislocation/instability

• Clinical presentation

  • Prominent posterior shoulder and coracoid for acute posterior dislocation

  • Limited external rotation for acute posterior dislocation (locked in internal rotation)

  • Pain on flexion, adduction and internal rotation for posterior instability

Imaging

• Xrays

• CT scan required

Treatment depends on the size of the defect and the duration of the dislocation

• If the defect <25%

  • If dislocation < 3 weeks : attempt closed reduction under anesthesia. if fails, open reduction

  • if dislocation >3 weeks: open reduction (deltopectoral approach)

• If defect >25% but <50%

  • If <6 months: Mc Laughlin transfer of the sub scapularis upper third . Bony sutures or plicature

  • auto or allo graft (bone)

• If defect >50% or dislocation > 6 months: Hemiarthroplasty or anatomical total arthroplasty (if glenoid erosion)