Multidirectional Instability

 

 

 

Definition

 

Instability in at least 2 planes

- postero-inferior

- antero-inferior

- antero-postero-inferior

 

Epidemiology

 

Pathology

 

Inherent ligament laxity / collagen abnormality

 

- patulous capsule anterior and posterior

- enlarged inferior axillary capsular pouch

 

History

 

Often bilateral

 

Instability of other joints

 

Severe instability

- feeling of shoulder "slipping down" while carrying heavy loads

- with sleeping

- subluxation with shoulder movement

 

Examination

 

Ligamentous laxity / Beightons score

 

Sulcus Sign - pull inferiorly on the arm, humerus subluxes inferiorly

 

 

Anterior instability - anterior draw / anterior load and shift / anterior apprehension + positive Jobe's relocation

 

Posterior instability - posterior draw / posterior load and shift / posterior apprehension / jerk test

 

Severe MDI - shoulder is anteroinferiorly subluxed at rest

 

Xray

 

Traction xray

- patient standing with 5-10 kg in each hand

- inferior subluxation of head

 

 

CT / MRI

 

 

Non-operative management

 

Mainstay of treatment

 

Operative results poor

 

Operative management

 

Options

 

Arthroscopic capsular plication

 

Open Neer and Foster inferior capsular shift

- anterior approach - anteroinferior instability

- posterior approach - posteroinferior instability

 

 Arthroscopic capsular plication

 

Technique

 

Anterior capsular plication

- option 1:  Suture plicate capsule to labrum

- option 2:  Anchors in glenoid and use to plicate capsule to labrum

 

Anterior capsular plication with sutures

 

Anterior capsular plication with suture anchors

 

Posterior capsular plication

- option 1:  Suture plicate capsule to labrum

- option 2:  Anchors in glenoid and use to plicate capsule to labrum

 

 

 

 

Results

 

Baker et al Am J Sports Med 2009

- 43 patients average age 19 years

- 86% return to sport

 

Open Anteroro - Inferior Capsular Shift

 

 

Technique

 

Principle

- detach capsule from neck of humerus

- shift capsule superiorly to obliterate the inferior pouch and decrease joint volume

 

Deltopectoral approach

- split subscapularis

- can perform subscapularis tenotomy and later tighten / Putti Platt

- T shape capsulotomy of capsule

- vertical component on articular margin humeral insertion all the way posterior

- transverse component to midpoint glenoid making superior and inferior flaps

- superior advancement inferior capsular flap

- eliminate inferior pouch and reduce posterior capsular redundancy

- then suture down superior flap

 

Open capsular plication

 

 

Open anterior capsular plication with subscapularis tenotomy and lateral advancement / Putti Platt

 

Results

 

Bigliani et al JBJS Am 2000

- 52 shoulders with open inferior capsular shift

- approach posterior or anterior depending on greatest instability

- 96% remained stable at average 61 months

- 60% excellent and 30% good results

- 70% athletes able to return to sport at same level

 

Ogilvie-Harris Br J Sports Med 2002

- contact athletes

- antero-inferior capsular shift in 37 with 3 recurrences (8%)

- posterior-inferior capsular shift in 16 with 2 recurrences (1 anterior / 1 posterior)(12%)

- 80% return to sport in antero-inferior capsular shift

- 75% return to sport in postero-inferior capsular shift

- only 17% return to sport if bilateral procedures

 

 Open posterior capsular plication

 

Technique

 

AO surgical foundation posterior approach glenoid / scapula

 

Lateral Position

- vertical incision over glenohumeral joint

- elevate deltoid or split deltoid

- interval: between supraspinatus and infraspinatus

- interval: between infraspinaus and teres minor

- can detach infraspinatus tendon and elevate off capsule

- suprascapular nerve 1.5cm medial to glenoid

- axillary nerve below teres minor

- perform capsular plication / capsular shift

- +/- lateral advancement of infraspinatus

 

Open posterior capsular plication in lateral position

 

Open posterior approach in beach chair with detachment of deltoid

 

Infraspinatus tenotomy

 

 

 

Posterior glenohumeral capsule reconstruction with allograft

 

Indication

 

Recurrent posterior instability

Ligamentous laxity

 

Technique

 

Arthroscopic posterior capsule reconstruction with acellular dermal allograft PDF

 

Open posterior capsular reconstruction with acellular dermal allograft PDF / video

 

Thermal Capsular Shrinkage

 

Results

 

Miniaci et al JBJS Am 2003

- 19 patients with MDI

- 9 recurrent instability

- 4 had parasthesia in AXN, one had deltoid weakness, all resolved

- worse results in posteroinferior compared with anteroinferior