Rotator cuff tears

epidemiology

· older patients

· average age is 60

· uncommon before age 40

· incidence in cadavers is 30%

· 70% in age > 80

· most commonly involves supraspinatus

· infraspinatus and teres minor may be torn

· subscapularis seldom torn

pathogenesis

Impingement

· part of advanced impingement (stage III)

· causative factors are

· ischaemia from hypovascularity

· wear from mechanical encroachment

· trauma from overuse

Injury

· acute episode of trauma may precipitate tear

· tear usually occurs through diseased tendon

· patient usually > age 40

· tear in normal tendon uncommon

· accounts for 5% of cuff tears

· most common injury is anterior shoulder dislocation

· may be mistaken for axillary nerve palsy

· may be associated with fracture of greater tuberosity

classification

Size

Small

· < 1 cm

Moderate

· 1-3 cm

Large

· 3-5 cm

Massive

· > 5 cm

Extent

Incomplete

Intratendinous

· within tendon

· no communication with bursa or joint

Joint side

· on articular (deep) surface

· blood supply poorer

· healing impaired by synovial fluid

Bursal side

· on subacromial surface

· less common

Complete

One tendon

· tear of supraspinatus only

Multiple tendons

· tear of supraspinatus plus

· infraspinatus

· subscapularis

Secondary OA

· cuff arthropathy

Topography

Sagittal plane

Superior

· supraspinatus alone

Anterosuperior

· supraspinatus plus subscapularis

Posterosuperior

· supraspinatus plus upper half or all of infraspinatus

Total cuff

· all 3 tendons

· usually with cuff arthropathy

Frontal plane

Proximal stump close to insertion

· little retraction

Proximal stump at humeral head

· moderate retraction

Proximal stump at glenoid

· significant retraction

clinical features

· two groups

1. due to inflammation (see impingement)

2. due to tear (below)

History

Pain

· usually related to cuff inflammation rather than tear

Weakness

· usually related to tear

Examination

Wasting

· of supraspinatus and infraspinatus

· rapid wasting with acute tears

· more gradual wasting with chronic tears

Weakness

· findings related to

· size of lesion

· amount of pain

· supraspinatus

· patient’s arm held elevated at 90^o with arm in 30^o forward flexion and palm down

· test resistance to downward pressure

· infraspinatus

· patient’s arm held by side in neutral

· test resisted external rotation

· subscapularis

· lift-off test

· ahoulder internally rotated and elbow flexed

· back of hand rests on lower lumbar area

· test ability to lift hand off back

Palpable gap

· defect may be palpable

· anterior to acromion with extension of shoulder

Drop arm sign

· inability to maintain passively elevated arm

· may be absent with small tear

· may be present with intact cuff if pain extreme

· persistence of drop arm sign after injection of local anaesthetic suggests large cuff tear

Crepitus

· suggestive of complete cuff tear

approach

Acute tear

· acute tear suspected if

· history of injury (esp. dislocation)

· minimal or intermittent symptoms of impingement preinjury

· significant atrophy and weakness of cuff

· drop arm sign after injection with local anaesthetic

· no degenerative changes on x-ray

· x-ray shows superior migration of humeral head

· early intervention indicated

· investigation with ultrasound, CT-arthrogram, MRI, arthroscopy

· prompt repair if significant cuff tear identified

· repair within 6 weeks

· is technically easier because defect from retraction minimised

· gives better movement and strength

Chronic tear

· chronic tear suspected if

· long history of continuous symptoms of impingement

· no history of injury

· minimal weakness of cuff

· degenerative changes on x-ray

· may be difficulty in differentiating cuff tear from tendinitis alone

· if diagnosis unclear, initial treatment as for impingement

· rest and activity modification

· NSAIDs

· steroid injection

· stretching and strengthening

· satisfactory outcome in 50%

· tears do not heal because of presence of synovial fluid

· if not improved in 3 months, further investigation warranted

· ultrasound or CT-arthrogram

· if tear identified, surgical repair if significant disability from pain or weakness

treatment

Nonoperative

· as for impingement

Operative

Technique

· anterosuperior approach through sabre incision

· acromioplasty performed in most cases

· not necessary in acute tear in normal tendon

· coracoacromial ligament is important passive constraint to upward movement of humeral head

· rotator cuff freed from scar and carefully inspected

· humeral rotation and abduction

Incomplete tears

· normal shiny surface replaced by hyperaemic roughened area

· most common in supraspinatus just lateral to bicipital groove

· abnormal tendon excised as ellipse

· tendon edges directly repaired with absorbable 1 sutures

Complete tears

· may be longitudinal split in normal tendon of young people

· usually L-shaped in diseased tendon

· longitudinal split

· transverse avulsion from insertion

· chronic tears may appear rounded

· secondary to proximal retraction of tendon

· tear completely identified

· edges trimmed

· tendon mobilised

· digital stripping of upper and lower surfaces from scar

· insertion of traction sutures

· primary repair of cuff preferable

· use combination of

· direct suture of tendon

· suture of tendon to bone

· for suture of tendon to bone

· trough made in bone in anatomical neck near tuberosities

· drill-holes made in trough

· tendon sutured through drill-holes

· repair should be performed with arm by side

· arm may be abducted during procedure to aid repair

· should be able to be brought by side at completion

· if direct suturing unfeasible, Y closure performed (McLaughlin technique)

· tendon defect made triangular with base at insertion

· apex closed as far as possible with shoelace suture

· unclosed tendon edges sutured to cancellous bone of humeral head

· in massive tear, more aggressive methods

· advancement of supraspinatus

· transposition of subscapularis

· biceps tendon graft

· free graft with coraco-acromial ligament, fascia lata or synthetic materials

· simple debridement of tear in older patients for pain relief

· subscapularis transposition

· subscapularis exposed by flexing and externally rotating arm

· subscapularis detached starting at medial corner of defect and continuing inferiorly and medially

· tendon detached from capsule

· tendon-to-tendon repair superiorly to remaining supraspinatus

· tendon-to-bone repair at site of avulsion from humerus

Postoperative

· arm in shoulder immobiliser for 2-3 weeks

· arm in abduction splint only if repair tight and tissues poor

· start hand and elbow exercises on first postoperative day

· passive ROM exercises within limits of repair after 1 week

· active assisted and isometric exercises after 3 weeks

· wait 6 weeks before active elevation allowed

· return to light activities after 8 weeks

· return to sport after 4 months

Results

· satisfactory outcome in 60-80%

Prognosis

· repair more difficult with

· large tear

· neglected tear

· older patient (>60)

· poor results likely

· unrecognised AC jt pathology

· inadequate subacromial decompression

· damage to deltoid

· excessive acromionectomy

· improper rehabilitation

· repeat tear likely with

· massive tear

· poor quality tendon

· inadequate repair

· persistent subacromial impingement

complications

Cuff arthropathy

· syn. Milwaukee shoulder

· collapse of humeral articular surface in association with massive cuff tear

· occurs in 5% of patients with massive cuff tear

· result of rubbing of uncovered and upwardly displaced humeral head on undersurface of coracoacromial arch

· loss of articular surface of humeral head leads to destruction of glenoid surface

· best treated with humeral hemiarthroplasty