Shoulder

Rotator Cuff

Impingement.

Causes:

1. Internal Factors
   • Age
   • Use
2. External Factors
   • Acromial Hypertrophy
   • Osteophytes from ACJ
   • Hooked Acromion (= Type 3)
   • Os Acromiale.

Definitions

Use Tendinosis or tendonopathy.

Massive

More than 2 tendons involved.
or, >5cm in AP dimension.

Goutalier Classification of Muscle Atrophy.

Grade	Description	Notes
0	Normal Muscle
1	Some Fatty streaks
2	<50% Fatty Atrophy
3	50% Fatty Atrophy	Poor prognosis for repair
4	>50% Fatty Atrophy	Poor Prognosis for repair

Designed for CT but used in MR.

Surgery & Post-Op appearances.

1. Subacromial Acromial Decompression ( with subacromial bursectomy and acromioplasty )
   -- Shave Undersurface of Acromion.
   -- Resect part of anterolateral acromion.
   -- Resect inferior Osteophytes from ACJ.
   -- Resect coracoacromial ligament.
   -- +/- Distal Clavicle resection. (Mumford)

Thus, normal post-op = flat undersurface.
+/- Windowing of ACJ if Mumford.
+/- Fluid in region of resection is normal.

1. Rotator Cuff Tendon Repair.
   How it is done is f(age, activity level, location, type, size of tear)
   -- <30% of thickness = Debride.
   -- 30-70% = Debride to the cuff and suture the tendon.
   -- >70% = Treated as an FTT.
   -- FTT = Reattach at the GT with suture anchors.

Thus, normal post-op = Intermediate T1 + T2 ( = granulation tissue & fibrosis ).
But, NOT fluid signal in the tendon. However can have fluid in SASD bursa.

And, normal for fluid from GHJ to entor ACJ as no longer water-tight.

Suture Anchors
- Often biodegradeable.
- Often osteolysis/cystic change = Inflam reaction.

Post-Op Retears

FTT = Abnormal fluid signal in the tendon defect. Or, non-visualisation of the tendon.

PTT = DIFFICULT.

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Biceps Tendon

Anatomy

Biceps Pulley

= Transition of the intra and extra-articular at lateral edge of the rotator interval.

The superior glenohumeral ligament (SGHL) and coracoacromial (CHL), and a few fibres of supraspinatus and subscapularis wrap around the biceps tendon to form the "biceps pulley"

Partial Tendon Thickness

Rad:
- Diffuse thinning or attenuation of the tendon.
- Linear High T2 signal clefts usually 2-3 cm from origin at the border.

Displacement

Displacement is related to subscapularis tendon tear. Thus,
If tear in biceps pulley and subscapularis => Intra-articular dislocation of LHBT.
If tear in biceps pulley but no subscapularis tear => LHBT tends to dislocate medially but superficial to the subscapularis tendon.
If tear in biceps pulley but transverse humeral ligament + Subscapularis tendon are intact => LHBT dislocates into substance of the subscapularis tendon and can cause interstitial tearing.

Rx: Tendonosis + Low grade injuries => Conservative +/- injection.
Severe Injuries => Debridement or tendon.....

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Labrum & SLAP

SLAP = Focal tear in the superior labrum centred at origin of the LHBT and extending in an anterior to posterior dimension with or without extension into periarticular soft tissues.
eg LHBT, GHL, Rotator interval.

Main issues is Normal variants:
i) Sublabral Recess
- 11 to 1 o'clock.
- Smooth margin
- Parallel to glenoid margin
- No extension into labral substance.

ii) Sublabral Foramen
- Focal detachment of the labrum.
- Only from 1 to 3 o'clock.
- Anymore is a tear.

iii) Buford Complex
- Congenital absence of anteriosuperior labrum from 1 to 3 o'clock.
- With thick, cord like MGHL
- On axial it is NOT a tear because of blending of the MGHL with underlying subscapularis tendon.

Snyder started the whole SLAP thing with >10 now but old skool rools.
Original Classification.

Type	Path	Notes
I	Wearing / fraying Superior labrum.	Often asymptomatic in old.
II	Separation of biceps anchor/superior labrum from underlying glenoid	Most Common
III	Displaced bucket handle tear without extension into LHBT.
IV	Bucket handle tear in the LHBT	Just describe the extension of the tear

Assess on coronal plane but axial also useful for adjacent structures.
Tear = abnormal high signal in substance of labrum +/- displaced fragments.