Table 5. Various Forms of Shoulder Instability Described using the FEDS System.

There are 36 potential classes of shoulder instability.

Solitary, Traumatic, Anterior Subluxationa	Solitary, Traumatic, Anterior, Dislocationa	Solitary, Traumatic, Inferior, Subluxation	Solitary, Traumatic, Inferior, Dislocationb	Solitary, Traumatic, Posterior, Subluxation	Solitary, Traumatic, Posterior, Dislocatione
Solitary, Atraumatic, Anterior, Subluxation	Solitary, Atraumatic, Anterior, Dislocation	Solitary, Atraumatic, Inferior, Subluxationc	Solitary, Atraumatic, Inferior, Dislocationd	Solitary, Atraumatic, Posterior, Subluxation	Solitary, Atraumatic, Posterior, Dislocation
Occasional, Traumatic, Anterior Subluxationa	Occasional, Traumatic, Anterior, Dislocationa	Occasional, Traumatic, Inferior, Subluxation	Occasional, Traumatic, Inferior, Dislocation	Occasional, Traumatic, Posterior, Subluxation	Occasional, Traumatic, Posterior, Dislocation
Occasional, Atraumatic, Anterior, Subluxation	Occasional, Atraumatic, Anterior, Dislocation	Occasional, Atraumatic, Inferior, Subluxationc	Occasional, Atraumatic, Inferior, Dislocation	Occasional, Atraumatic, Posterior, Subluxation	Occasional, Atraumatic, Posterior, Dislocation
Frequent, Traumatic, Anterior Subluxationa	Frequent, Traumatic, Anterior, Dislocationa	Frequent, Traumatic, Inferior, Subluxation	Frequent, Traumatic, Inferior, Dislocation	Frequent, Traumatic, Posterior, Subluxation	Frequent, Traumatic, Posterior, Dislocation
Frequent, Atraumatic, Anterior, Subluxation	Frequent, Atraumatic, Anterior, Dislocation	Frequent, Atraumatic, Inferior, Subluxationc	Frequent, Atraumatic, Inferior, Dislocation	Frequent, Atraumatic, Posterior, Subluxation	Frequent, Atraumatic, Posterior, Dislocation

Uncommon classes (N=15) are in italics. Some commonly used terms for shoulder instability would be reclassified in this system:

^aTUBS (Traumatic Unidirectional Bankart Surgery ³⁹),

^bLuxio Erectae,

^cAMBRI (Atraumatic, Multidirectional, Bilateral, Rehabilitation, Inferior capsular shift ³⁹),

^dNeurologic Shoulder