Arthroscopic Management of Posterior Instability

Mike Walton@mrmikewalton mikewalton@shoulderdoc.co.uk

Santander 2015

How Common is it?

• Traditional estimates of posterior instability were 2-5%

• Often discussed with atraumatic and MDI

• Our practice seemed to be very different

• High volume of athletesAm J Sports Med. 2011 Apr;39(4):874-86. doi: 10.1177/0363546510384232. Posterior instability of the shoulder: diagnosis and management. Provencher MT1, LeClere LE, King S, McDonald LS, Frank RM, Mologne TS, Ghodadra NS, Romeo AA

How Common is it?

• 3 Surgeons, 3 years

• 442 shoulder arthroscopic stabilisations

• Specialist Shoulder practice

• Mean age 26, 87% Male

How Common is it?

• 75% Sporting Population (Recreational to Elite)

• 48% Isolated Anterior, 17% Isolated Posterior

• 35% Combined Lesions

• Non-Sporting population older with 68.5% isolated anterior labral tear

How Common is it?

• RUGBY (n=231)

• 53% Posterior labral lesion (13% Posterior, 40% combined lesions)

• If you treat these patient you MUST be able to treat this lesion.

Presentation

• Anterior instability

• Occasionally posterior dislocations

• Subluxation episodes

• WEAKNESS

• CUFF PAIN

Assessment

Lewis A, Kitmura T & Bayley JIL. The classification of shoulder instability: new light through old windows!Current Orthopaedics, 2004; 18(2):97-108.

Atraumatic Instability

Modified O’Briens Test

• Forward Elevation to 90

• Adduction / Internal Rotation

• Pain - SLAP

• WEAKNESS - Post Instability

Modified O’Briens Test

• Posterior Translation occurs in simulated Active Compression Test

J Shoulder Elbow Surg. 2013 Mar;22(3):365-74. doi: 10.1016/j.jse.2012.02.003. Epub 2012 May 19. Glenohumeral contact pressure in a simulated active compression test using cadaveric shoulders. Lin T1, Javidan P, McGarry MH, Gonzalez-Lomas G, Limpisvasti O, Lee TQ.

Investigations

• MR Arthrogram

• Accurate for isolated anterior and posterior lesions (78.5%, 69%)

• Accuracy ONLY 37% in combined lesions

Sitting or Spoons

Sitting or Spoons

DONT FORGET THE EUA

Sitting or Spoons

PosteroLateral Portals

PosteroLateral Portals

PosteroLateral Portals

If the angle is wrong..

Reverse HAGL

Reverse HAGL

Reverse HAGL

Rehabilitation

• External Rotation brace 2 weeks

• Highly specialist physiotherapy

• More Atraumatic - More Physio

• Kinetic Chain and Cuff Rehabiliation

Failures and Bone Loss

Failures and Bone Loss