Normal Anatomical Variants

Steve CorbettGuys and St Thomas’ NHS Foundation Trust

Normal Anatomical Variants

Normal Anatomical Variants

Normal Anatomical Variants

Normal Anatomical Variants

• Superior labrum / Biceps• Anterosuperior Quadrant• AI Quadrant• PI Quadrant

• PS Quadrant

• Biceps• AS head• Superior Cuff / Head• Posterior Cuff / Head

• GHJ Surfaces• Bursa

Normal Anatomical Variants: Superior labrum/Biceps

Normal Anatomical Variants: Superior labrum/Biceps

Normal Anatomical Variants: Superior labrum/Biceps

• 15% loosely attached meniscal type labrum

• 1-5mm width

Normal Anatomical Variants: Superior labrum/Biceps

Superior labrum/Biceps: SLAP

• Anatomy

– Type I 22%– Type II 33%– Type III 37%– Type IV 8%

I II

III IV

Normal Anatomical Variants: Superior labrum/Biceps

Normal Anatomical Variants: Superior labrum/Biceps

• Vincula Biceps

– Small strands of mesentry

– Pass from biceps to surrounding capsule

• Bifid Biceps

– 1 part attached to cable

– 2nd part attached to tubercle

• Complete absence

Normal Anatomical Variants: Superior labrum

• 80% firmly attached

• 14-60% sublabral foramen (Detrisac and Johnson 20% anatomic dissections)

• 6% Burford Complex

Normal Anatomical Variants: Superior labrum

• 80% firmly attached

• 14-60% sublabral foramen (Detrisac and Johnson 20% anatomic dissections)

• 6% Burford Complex

Normal Anatomical Variants: Superior labrum

• 80% firmly attached

• 14-60% sublabral foramen (Detrisac and Johnson 20% anatomic dissections)

• 6% Burford Complex

Normal Anatomical Variants: Superior labrum

• 80% firmly attached

• 14-60% sublabral foramen (Detrisac and Johnson 20% anatomic dissections)

• 6% Burford Complex

Normal Anatomical Variants: Superior labrum

• 6% Burford Complex

– Cord like MGHL

– No labral tissue ant/sup glenoid

– Surfaces smooth

Normal Anatomical Variants: Superior labrum

• 6% Burford Complex

– Cord like MGHL

– No labral tissue ant/sup glenoid

– Surfaces smooth

Normal Anatomical Variants: Superior labrum

• 6% Burford Complex

– Cord like MGHL

– No labral tissue ant/sup glenoid

– Surfaces smooth

Normal Anatomical Variants: Superior labrum

• Divides sup. 2/5 and inf. 3/5.

• Variable in depth

Normal Anatomical Variants: Subscapularis / SGHL

• Leading edge may be split or bifid

• 3%

• SGHL present in nearly 100%, Occassionally frayed

Normal Anatomical Variants: MGHL

• Most variable of all ligaments

– Variable origin

– 70% folded thickening crossing subscapularis at 45º

– 20% cord like

– 10% thin veil or absent

Normal Anatomical Variants: MGHL

• Most variable of all ligaments

– Variable origin

– 70% folded thickening crossing subscapularis at 45º

– 20% cord like

– 10% thin veil or absent

Normal Anatomical Variants: MGHL

• Most variable of all ligaments

– Variable origin

– 70% folded thickening crossing subscapularis at 45º

– 20% cord like

– 10% thin veil or absent

Normal Anatomical Variants: Anterior Inferior Labrum

• 95% smooth attachment

• 5% meniscoid– Probe can be inserted

but labrum not detached

Normal Anatomical Variants: Anterior Inferior Labrum

• 95% smooth attachment

• 5% meniscoid– Probe can be inserted

but labrum not detached

Normal Anatomical Variants: IGHL

• aIGHL

– Variable attachment to labrum

– Distinct superior band not always present (Defined by Turkel et al)

– May hypertrophy when MGHL absent

Normal Anatomical Variants: Inferior capsular recess

• Normally smooth

• Delicate synovial covering

• Small fenestrations

• Post. Sup. Band pIGHL not always well visualised (Schwartz et al)

Normal Anatomical Variants: Bare area

• Bare area– 2-3 mm– 2-3 cm– Frequent indentations,

deep holes

– Size varies with age (De Palma)

Normal Anatomical Variants: Bare area

• Must distinguish from Hill Sachs

Normal Anatomical Variants: Superior cuff

• Layer of capsule and synovium

• Rotator cable

Normal Anatomical Variants: Posterosuperior cuff

• May have fenestrations in superficial layers

Normal Anatomical Variants: Posterior labrum / Capsule

• 95% firmly attached

• 5% meniscoid, firmly attached at periphery

Normal Anatomical Variants: Posterior labrum / Capsule

• Normal to have a deep cleft in capsule posterior to labrum

Thank you