Common Shoulder Problems

Dr. Andreas Panagopoulos, MD, Ph.D.

Upper Limb & Sports Orthopaedic Surgeon
Lecturer in Orthopaedics, Patras University Hospital
Definitions

 Limited bony contact between the humeral

head and glenoid fossa allows extended range of
motion at a cost of relative instability

 There must be a balance between mobility and

stability to maintain proper function
Anatomy SS

SSC

IS

TM
Mechanical shoulder pathology

 overuse,
 extremes of motion, or
 excessive forces

Disruption of the delicate balance of the shoulder

complex resulting in tears of the rotator cuff,
capsule, and labrum
Mechanical shoulder pathology

 Impingement – RC injury

 instability

 overhead athlete (internal impingement)

IMPINGEMENT SYNDROME
Historical perspective

Jarjavay, 1867 : first description of «subacromial bursitis»

Duplay, 1872 : described the «periarthritis humeroscapularis»

Meyer, 1931 : he attributed that RC tears caused by the trimming of the

supraspinatus tendon underneath the acromion

Codman, 1934 : described the “critical jone” of the supraspinatus tendon

near the GT insertion

Amstrong, 1949 : he introduced the term “supraspinatus syndrome” and

proposed «total acromionectomy»

McLaughin, 1951 : suggest the “lateral acromionectomy”

Etiology - pathogenesis

Narrowing of the “supraspinatous outlet”

is the most frequent cause of impingement
Neer CS, 1972

Causes:

1. Anterior acromial spurs

2. Shape and slop of the acromion

3. AC joint spurs

4. Coracoacromial ligament
Etiology - pathogenesis

Three stages of impingement syndrome (Neer)

Stage I, characterized by subacromial edema and

hemorrhage, was typical in symptomatic patients
younger than 25 years of age.

Stage II included fibrosis and tendinitis and was more

common in persons 25 to 40 years old.

Stage III characterized by partial or complete tendon

tears typically in persons older than 40 years of age.

95% of all rotator cuff lesions to primary mechanical

impingement.
 Anatomy

Layer
Layer1:1:superficial
deltoid and
layer
pectoralis
CHL major
Layer
Layer2:2:main
continuous
portion fascial
of RC (//
layer
fibers)
Layer
Layer3:3:oblique
rotatorfibers
cuff tendons
merged
Layer
Layer4:4:deep
fibrous
extension
capsular
of the
elements
CHL
Layer 5: joint capsule
Biomechanics

Coronal plane force couple (Inman 1944):

The inferior portion of the rotator cuff
(below the center of rotation) creates a
moment that must balance the deltoid
moment.

Transverse plane force couple,

(Burkhart 1994) The subscapularis
tendon anteriorly is balanced against the
infraspinatus and teres minor tendons
posteriorly.
Biomechanics

“Rotator cable” extends from its anterior attachment

just posterior to the biceps tendon to its posterior
attachment near the inferior border of the infraspinatus
tendon
Biomechanics

“Suspension bridge”, with the free margin of the tear

corresponding to the cable and the anterior and posterior
attachments of the tear corresponding to the supports at
each end of the cable’s span

Tear size is less important than tear location in terms of force

couple and kinematic preservation
Biomechanics

Detachment of 1/3 or 2/3 of the SS tendon (in the crescent area)

has only a minor effect on the force transmission of the RC (1%
and 2%) and that not until the entire supraspinatus tendon was
detached was there a significant decrease (11%) in force
transmission.

Halder AM, O’Driscoll SW, Heer G, et al: J Bone Joint Surg 84A: 780–785, 2002
Biomechanics

In small and medium-sized RC tears, the muscle forces are

effectively transmitted along the rotator cuff cable, bypassing
the tear in the crescent portion of the supraspinatus.

Halder AM, O’Driscoll SW, Heer G, et al: J Bone Joint Surg 84A: 780–785, 2002
 Etiology - pathogenesis

Degenerative factors
- Proliferative and degenerative changes of
Traumatic factors
the acromion, coracoacromial ligament,
-Rotator cuff (acute trauma, overuse, work..)
acromioclavicular joint, or greater tuberosity
-Supraspinatus outlet (AC joint separation,
- Intrinsic degenerative changes of the rotator
coracoid nonunion, GT malunion….
cuff
Developmental factors Inflammatory disease
Os acromiale Calcific tendinitis or bursitis
Coracoid malformation Rheumatoid arthritis
Type II or type III acromial morphology Crystal-induced arthropathy

Capsuloligamentous factors Iatrogenic or acquired disorders

Instability Hardware placement
Capsular contracture Foreign materials
Tight posterior capsule Inferior placement of the humeral prosthesis
Corticosteroid-induced tendonopathy
Scapulothoracic neuromuscular dysfunction
Chronic cervical spondylosis
Entrapment syndromes
Serratus anterior palsy
Axillary nerve
Trapezius nerve palsy
Suprascapular nerve
Etiology - pathogenesis

Two predominate mechanistic theories

Intrinsic impingement, theorizes that partial or full thickness tendon

tears occur as a result of the degenerative process that occurs over time
with overuse, tension overload, or trauma of the tendons. Osteophytes,
acromial changes, muscle imbalances and weakness, and altered
kinematics leading to impingement will subsequently follow

Extrinsic impingement, where inflammation and degeneration of the

tendon occur as a result of mechanical compression by some structure
external to the tendon such as faulty posture, altered scapular or
glenohumeral kinematics, posterior capsular tightness, and acromial or
coracoacromial arch pathology.
Predominate mechanistic theories

Intrinsic impingement

Degenerative process that occurs over

time with overuse, tension overload, or
trauma of the tendons. Aging, healing,
and vascularity may predispose to
tendonosis and ultimately tendon failure.

Osteophytes, acromial changes, muscle

imbalances and weakness, and altered
kinematics leading to impingement will
subsequently follow
Predominate mechanistic theories

Extrinsic impingement

The
Result Superior
of mechanical
Shoulder
compression
Suspensory
by
some structure
Complex (SSSC) external
is a bony–soft
to thetissue
tendon
ring
such asup
made faulty
by posture,
the glenoid,
alteredcoracoid,
scapular or
and
glenohumeral
acromion processes,
kinematics,
as well as posterior
the distal
clavicle,
capsular thetightness,
AC joint, and
andCCacromial
ligaments.or
coracoacromial arch pathology
Intrasubstance RC tears

Horizontal partial tears of the

rotator cuff (along the length of the
tendon) have also been described
and thought related to shear
stresses.

Shear forces are probably directed

to layer four, which is the site of
development of intratendonous cuff
tears. These tend to be degenerate
tears of the cuff.
Etiology - pathogenesis

…the question is, which comes first, tendon

degeneration or changes external to the tendon?

By the time a patient with SAIS seeks health care,

the typical examination findings reveal tendon
pathology in some form and the presence of one or
more extrinsic factors such as osteophytes or
muscle weakness.
….we believe that 90 to 95 per cent of abnormalities of the
rotator cuff are secondary to tension overload, overuse, and
traumatic injury.

There is no objective evidence that primary extrinsic factors

are involved in most disorders of the rotator cuff, as changes
within the rotator cuff often occur without accompanying
changes on the acromion
Clinical examination

Painful arc sign Drop arm sign Neer’s test Hawkin’s test

Speed’s test Cross adduction test Infraspinatus strength Supraspinatus strength

Radiological evaluation

axillary

anteroposterior Anteroposterior with

30o caudal tilt
Radiological evaluation

Acromial angle Lateral acromial angle

17%
3%

43% 24%

40% 73%

Acromial slope Acromial type

Ultrasound

Office-based ultrasonography led to the correct

diagnosis for 88% of the shoulders with a full-
thickness rotator cuff tear, 70% with a partial-
thickness rotator cuff tear only, and 80% of
normal tendons
Magnetic resonance imagine

Comparison of MRI and operative

findings in full-thickness RC tears showed
sensitivity of 85%, specificity of 83% and
PPV = 99%
In partial-thickness tears the values were
respectively 83%, 85, PPV = 39%
US or MRI?

The overall accuracy for both imaging tests was 87%.

 Small <1 cm
ASES
Medium 1-3 cm
Large 3-5 cm
Massive > 5 cm
 Partial articular side tear Partial bursal side tear

PASTA

Partial Articular Supraspinatus Avulsion Tear Intratendinous tear

Classification of large tears based on shape and retraction

4 basic patterns

Crescent-shaped U-shaped L-shaped Massive, contracted,

immobile tears

Burkhart SS: Arthroscopic treatment of massive rotator cuff tears. Clin

Orthop 390: 107–118, 2001
Initial nonoperative care can be safely undertaken in:

• in older patients (>70 years old) with chronic tears

• patients with irreparable rotator cuff tears with irreversible changes,
• patients of any age with small (<1 cm) full-thickness tears or in
• patients with partial-thickness tears

Early surgical treatment can be considered in

significant (>1 cm–1.5 cm) acute tears or young patients with full-
thickness tears who have a significant risk for the development of
irreparable rotator cuff changes.
Calcified tendinitis supraspinatus
Conclusions

SIS and RC tearing appear to result

from a variety of factors.

- anatomical factors of inflammation of

the tendons and bursa,
- degeneration of the tendons,
- weak or dysfunctional rotator cuff
musculature,
- weak or dysfunctional scapular
musculature,
- posterior glenohumeral capsule
tightness,
- postural dysfunctions of the spinal
column and scapula and
- bony or soft tissue abnormalities of
the borders of the subacromial outlet
GLENOHUMERAL INSTABILITY
Definition

Glenohumeral laxity is the ability of the

humeral head to be passively translated on
the glenoid fossa

Glenohumeral instability is “a clinical

condition in which unwanted translation of
the head on the glenoid compromises the
comfort and function of the shoulder.”

Matsen FA III, Harryman DT, II Sidles JA. Mechanics of glenohumeral

instability. Clin Sports Med. 1991;10:783-788
Classification (Matsen)

TUBS or “Torn Loose”

Traumatic etiology
Unidirectional instability
Bankart lesion
Surgery is required

AMBRI or “Born Loose”

Atraumatic: minor trauma
Multidirectional instability may be present
Bilateral: asymptomatic shoulder is also loose
Rehabilitation is the treatment of choice
Inferior capsular shift: surgery may needed
Classification Dislocation
Subluxation
Degree Subtle

Acute (primary)
Frequency
Chronic
Recurrent
Fixed

Etiology

Traumatic (macrotrauma)
Direction
Atraumatic 1.Unidirectional
Voluntary (muscular) -Anterior
Involuntary (positional) -Posterior
Acquired (microtrauma) -Inferior
Congenital 2. Bidirectional
Neuromuscular -Anteroinferior
(Erb's palsy, cerebral palsy, seizures) -Posteroinferior
3. Multidirectional
Classification
significant trauma
often a Bankart’s defect
usually unilateral
no abnormal muscle patterning

no trauma
no trauma (habitual)
structural damage to joint surfaces
no structural damage to joint surfaces
capsular dysfunction
capsular dysfunction
no abnormal muscle patterning
abnormal muscle patterning
not uncommonly bilateral
often bilateral
1st law of glenohumeral stability

The GH joint will not dislocate as long as the

net humeral joint reaction force is directed
within the effective glenoid arc

- This force is the resultant of all muscular,

ligamentous, inertial, gravitational, and other
external forces applied to the head of the
humeral head (other than the force applied by
the glenoid)
2nd law of glenohumeral stability

The humeral head will remained centered in

the glenoid fossa if the glenoid and humeral
joint surfaces are congruent and if the net
humeral joint reaction force is directed
within the effective glenoid arc.

- The "effective glenoid arc" is the arc of

the glenoid available to support the humeral
head under the specified loading conditions
Balance stability ratio & angle

The stability ratio is the force necessary to

displace the head from the glenoid divided
by the load compressing the head into the
concavity. Clinically, the stability ratio can be
sensed using the "load and shift" test

- Resection of the labrum has been shown to

reduce the stability ratio by 20 per cent. (Lippitt,
Vanderhooft, Harris et al, 1993)

The balance stability angle is the maximal

angle between the glenoid center line and the
net humeral joint reaction force before the
humeral head dislocates from the glenoid

- A 3 mm anterior glenoid defect has been shown

to reduce the balance stability angle over 25 per
cent. (Matsen, Lippitt, Sidles et al, 1994)
Factors maintaining shoulder stability

Static Factors Dynamic Factors

Articular version-conformity Rotator cuff

Glenoid labrum Coracoacromial arc
Capsule and ligaments Biceps brachii
Adhesion–cohesion & suction cup Proprioception
Negative intraarticular pressure
Rotator cuff (static contribution)

no single factor is responsible for glenohumeral joint stability

and no single lesion is responsible for clinical instability
Articular version - conformity
Scapula: a. faces 300 anteriorly on the chest wall
b. tilts 3 degrees upward relative to the transverse plane
c. 20 degrees forward relative to the sagittal plane
Glenoid has a superior tilt of 5 degrees and 70 retroversion in 75% of patients

Scapular inclination may have a contributory role in controlling inferior stability.

Articular version- conformity

Dias et al (1993) & Dowdy and O'Driscoll (1994) found no

difference or only minor variances in apparent glenoid version
between normal subjects and recurrent anterior dislocators.

Hirschfelder and Kirsten (1991) found increased glenoid

retroversion in both the symptomatic and unsymptomatic
shoulders of individuals with posterior instability

Grasshoff et al (1991) found increased anteversion in

shoulders with recurrent anterior instability.

When it is important to know the orientation of

the cartilaginous joint surface in relation to the
scapular body a double contrast CT scan is
necessary
Articular version - conformity

the humeral head has a surface area that is three times that of the glenoid

48

35
25
45

golfball sitting on a tee

In fact, the articular surfaces of the humeral head and glenoid are almost perfectly matched
with a congruence within 3 mm, with deviations from sphericity of less than 1%

Soslowsky L, Flatow E, Bigliani L, et al. Articular geometry of the

glenohumeral joint. Clin Orthop 1992;285:181–190.
Glenoid labrum
1. Anchor point for capsuloligamentous structures
2. It doubles the anteroposterior depth of the glenoid from 2.5 to 5
mm and deepens the concavity to 9 mm in the superior-inferior plane.
3. Enhances stability of the joint by increasing the surface area of contact
for the humeral head.
4. The labrum is analogous to a chock-block preventing an automobile’s
wheel from rolling downhill
Capsule/Glenohumeral Ligaments

SGHL (together with the CHL) constrain the humeral

head on the glenoid, limit inferior translation and
external rotation of the adducted shoulder and posterior
translation of the flexed, adducted, internally rotated
shoulder.
*
MGHL limits anterior translation of the humeral head
* when the arm is abducted between 60° and 90°. The
MGHL dominant” individuals with a cord-like MGHL
* * * may be more dependent on this structure to provide a
protective role against anterior instability

IGHL complex acts like a hammock in preventing

increased translation of the humeral head on the
glenoid.

- abduction moves beneath the humeral head and becomes taut

- internal rotation moves posteriorly and limits posterior translation

- external rotation moves anteriorly and limits anterior translation

Adhesion-Cohesion & the Suction Cup

Neither the adhesion-cohesion nor the suction-cup

mechanism consumes energy, and both provide so
called low-cost centering when the arm is at rest.

These mechanisms also have the convenient property

of working in any position of the shoulder.

The suction-cup mechanism is enhanced by the slightly

negative intra-articular pressure within the joint.
Muscles
Concavity compression is the primary mechanism by which
the head of the humerus is centered and stabilized in the
glenoid fossa to resist the upward pull of the deltoid. The cuff
muscles provide stability by functioning as "compressors"
than as depressors

subscapularis muscle is the primary

anterior compressor (lumbar push-off test)

supraspinatus muscle is the primary

superior compressor (supraspinatus test)

infraspinatus is the primary posterior

compressor, assisted to a degree by the
teres minor (infraspinatus test)
 Muscles

The RC muscles they can function as head compressors in almost any position of the
glenohumeral joint.

Other muscles, such as the deltoid, long head of the biceps, pectoralis, latissimus,
teres major, and pectoralis major, can contribute to humeroglenoid compression in
certain glenohumeral positions.

The interplay between muscular and capsular tension

As the humerus is passively externally

rotated, the force that the subscapularis can
generate drops off while the force
generated by the anterior capsular
ligaments increases in a complementary
manner.
The Coracoacromial Arch

The centers of rotation for the humeral head,

the proximal humeral convexity, the glenoid
fossa, and the coracoacromial arch are all
superimposed in the normal stable shoulder

The critically important stabilizing effect of the

the coracoacromial arch is demonstrated by the
devastating anterosuperior instability that
results when an acromioplasty is performed in
the presence of rotator cuff deficiency
Biceps tendon

The biceps tends to stabilize the joint anteriorly with the arm in
internal rotation, and it acted as a posterior stabilizer with the arm
in external rotation.
Pathoanatomy, diagnostic imaging
and related lesions
Normal labral variations (13.5-25%)

a. A cord-like middle glenohumeral ligament

(MGHL)
b. Sublabral foramen in the anterosuperior
quadrant of the shoulder.
c. The Buford complex (cord-like MGHL in
conjunction with an absent anterosuperior
labrum complex
Pathologic lesions in shoulder instability

a. Bankart, bony-Bankart
b. PERTHES
c. ALPSA
d. HAGL
e. GLAD
f. SLAP
g. Hill - Sacks
Bankart lesion

A Bankart lesion is a tear of the anterioinferior glenoid labrum with an associated tear of
the anterior scapular periosteum, with or without associated fracture of the anterior
inferior glenoid rim.
Bony - Bankart lesion

Type I: 0-12.5%

Type II: 12.5-25%

Type III: >25%

A Bony - Bankart lesion is a tear of the anterioinferior glenoid labrum with an associated
tear of the anterior scapular periosteum, with associated fracture of the anterior inferior
glenoid rim.
ALPSA lesion

An ALPSA lesion is an anterior labroligamentous periosteal sleeve avulsion. ALPSA is a

variation of the Bankart lesion where the anterior inferior labrum is torn and the labrum,
inferior glenohumeral ligament and intact scapular periosteum are stripped and displaced
medially on the glenoid neck.

POLPSA is similar to ALPSA and is associated with posterior dislocation

Perthes lesion

An Perthes lesion is a variant of the Bankart, where the anterioinferior labrum is avulsed
from the glenoid and the scapular periosteum remains intact but is stripped medially.
HAGL lesion

A HAGL lesion is humeral avulsion of the glenohumeral ligament that occurs from
shoulder dislocation, with avulsion of the inferior glenohumeral ligament from the
anatomic neck of the humerus (J sign).
A BHAGL is a bony HAGL, or a HAGL lesion that involves a bone fragment
SLAP lesion Type II SLAP

Additional categories of SLAP tears were described

SLAP is an acronym for superior labral tears, that propagate anterior and posterior in
by Maffet et al , Morgan et al , Resnick and Beltran
reference to the biceps anchor. Originally, SLAP lesions were classified by Snyder et al,
based on arthroscopic evaluation
GLAD lesion

IGHL disruption

Glenoid cartilage
injury
Normal glenoid
cartilage

The GLAD lesion refers to glenolabral articular disruption, which involves a tear of the
anterior inferior labrum with an associated glenoid chondral defect.
Hill-Sachs lesion

< 20% leave alone

20-40% grey zone
> 40% need to treat
Engaging Burkhart
engages in functional position

The Hill-Sachs lesion is a cortical depression in the humeral head. It

results from its forceful impaction against the anteroinferior rim of the
glenoid when the shoulder is dislocated anteriorly

(reverse Hill-Sachs in posterior dislocation).

Open Surgical repair: categories

Anatomic
Capsulolabral reconstruction Bankart-Perthes, Rockwood,
DuToit staple capsulorrhaphy,
inferior capsular shift

Non -anatomic

Subscapularis procedures Putti-Plat, Magnuson-Stuck

Bone block procedures Oudard and Trillat, Eden-

Hybinette, J-graft

Coracoid transfer Bristow, Latarget-Patte

Osteotomy of Humerus Weber, Cautilli, Joyce and Mackell

 Capsulolabral reconstruction

“Bankart repair (1923, 1939)”

- first performed by Perthes (1906)

- shave off bone from the anterior glenoid

- reconstruction of the avulsed capsule and labrum at

the glenoid lip, using simple drill holes

- subscapularis, which is carefully divided to expose the

capsule, is re-approximate without shortening

- osteotomy of the coracoid

Subscapularis procedures

“Subscapularis shortening Putti-Platt (1925)”

“The rate of glenohumeral arthrosis is increased in patients who
have undergone a Putti-Platt procedure and is positively correlated
with the length of time since surgery”
Bone block procedures

“Eden-Hybinette Procedure (1932)”

- creation of a trough through the

capsule and into the anteroinferior
aspects of the scapula neck.

- a tricortical iliac crest bone graft

was then wedged into the trough
without fixation
Coracoid transfer

“Bristow - Helfet procedure (1958)”

- coracoid tip is transferred to the

anteroinferior glenoid neck and
serves as a bone block

- the transferred conjoined tendon

acts as a strong dynamic buttress
across the anterior and inferior
aspects of the joint
Humerus osteotomy

- subcapital osteotomy
- medial rotation of the head (250)
- shortening of the subscapulanis
tendon and capsule anteriorly

average loss of external rotation >5 degrees,

without noticeable diminution of power or
function in most patients. The results as
graded by a standard rating scale were good
to excellent in 90 per cent
Combination of capsulolabrar techniques

Repair of Bankart lesion

Inferior capsular shift

Neer CS, Foster CR :
Inferior capsular shift for involuntary inferior and
multidirectional instability of the shoulder. JBJS Am 1980

Reinforced cruciate repair

Neer CS, Fithian TE:
Reinforced cruciate repair for anterior dislocation of the
shoulder. Orthop Trans 1985

120 pt at Patras University Hospital (5% recurrences)

Clinical examination

History

Clinical tests
- apprehension test
- drawer sign

- sulcus sign
X-Rays
CT arthrogram
MRI arthrogram
Surgical steps beach chair position

axillary approach
(Ryan-Lesley)

Direction of the instability

(under anesthesia)
Subscapularis cut (leave 1/3 attached to the capsule)
The capsule is opened in “ T-shape”
Repair of capsulolabral detachment

Three holes with drill 2,5mm (3:00, 5:00, 7:00)

Glenocapsular reattachment with ethibon No 2 (Mitec G ΙΙ)
Inferior capsular shift
Cruciate repair
...to reinforce anterior capsule

arm position

Elbow flexion 90°

Shoulder lift

External rotation 10°

Subscapularis is reattached in its anatomical insertion
(without shortening)

No functional limitation of external

rotation
 POST OPERATIVELY
First 48 hours : Velpeau Till 4th week : controlled ext
rotation gradually to neutral
position
4th to 6th week : active After 6th week :
assisted immobilization muscular strengthening
Coracoid transfer

“Latarzet procedure (1958)”

- the gold standard treatment for

anterior glenohumeral instability in
the presence of glenoid bone loss
CA ligament

- 3 stabilizing mechanisms
- coracoid process acts as a bony extension
- conjoint tendon act as a soft tissue sling
preventing anterior subluxation
- the capsule can be repaired to the stumb of CA
ligament, thus providing a new, strong, inferior
glenohumeral ligament
Coracoid transfer

“Latarzet procedure (1958)”

The Latarjet reconstruction extends the

glenoid articular arc so that

1. off-axis loads are resisted by bone

rather than soft tissue

2. the humerus cannot externally

rotate enough to cause engagement
of the Hill-Sachs lesion over the
front of the graft.
CA ligament
Conclusions

A delicate balance between dynamic and static stabilizing factors

allow the arm to be placed in extreme positions for athletic and
work-related activities.

This concavity-compression mechanism is dependent on the

integrity of the glenoid and the coracoacromial arch, muscular
compression, and restraining ligaments of the shoulder.

Loss of any of these elements due to developmental,

degenerative, traumatic, or iatrogenic factors may compromise
the ability of the shoulder to center the humeral head in the
glenoid.
Conclusions

The questions to answer during an evaluation of a patient with

suspected instability are:

(1) Is the problem in the glenohumeral joint?

(2) Is the problem one of failure to maintain the humeral head in
its centered position?
(3) What mechanical factors are contributing to this instability?
(4) Are the identified mechanical factors amenable to surgical
repair or reconstruction?

This evaluation is based primarily on a carefully elicited

history, a physical examination of the stability mechanics, plain
radiographs and MRI scan
Conclusions

For surgical treatment of glenohumeral instability to be

appropriate, the instability must be attributable to
mechanical factors that can be modified by surgery.

The causes may be deficiencies of the glenoid concavity,

deficiencies in the muscles that compress the head into
the socket, and/or deficiencies in the capsule and
ligaments
INTERNAL IMPINGEMENT
Definition

Injury and dysfunction due to

repeated contact between the
undersurface of the rotator cuff
tendons and the posterosuperior
glenoid

Walch JSES 1992

 For undefined reasons this
Some contact between these contact in some athletes
structures is physiologic but become pathologic and
repetitive contact with altered produces symptoms
shoulder mechanics may be
pathologic
Mechanisms

Two major theories:

• Andrew
• Burkhart & Morgan

May co-exist
 Mechanism of Internal Impingement
Andrew Theory:

Repeated Dynamic Increase stress to

ABER stabilizers anterior & IGHL
fatigue

Anterior
Internal
capsule laxity
Impingement
to allow max
ABER

Increased contact of
undersurface of RC and Reduction of posterior &
posterosuperior glenoid inferior translation of HH
 Mechanism of Internal Impingement
Burkhart & Morgan Theory:

Repeated Tight posterior Superior

ABER capsule translation of
Humeral Head

Torsional
Increased contact of Internal stress to
undersurface of RC and Impingement biceps
posterosuperior glenoid
anchor

Peel-off
SLAP II and
Pseudolaxity Mechanism
 Internal Impingement

It is essentially an overuse injury associated with

overhead athletes
 Internal Impingement

• Typically symptoms are present only while playing

• No symptoms with activities of daily living

• Represents about 80% of the problems seen in the overhead

athletes
 during deceleration shortly after
Consequently, these forces may lead toball
maximal external rotation subacromial impingement
release where compressive
where 310 N translation
(superior of anteriorly of humeral headforces
fromreachcompressive forces),
1090 N and posterior
directed forces were generated forcesthe
reach labrum),
400 N
labral
along withtears
67 Nm of(torsional
torque forces grinding and cuff
failure (large tensile forces with collagen failure).
History

• Insidious onset

• Increases as the season progresses

• Dull posterior pain

• Worse at late cocking phase

• Rarely can remember any traumatic episode

• Loss of control and velocity

 Clinical Examination

Provocative tests:

– Internal Impingement test = positive

(patient supine, 90 deg abduction and max external rotation. If pain
experienced at the posterior part of the joint = positive, 90%
sensitive)

– Relocation test = positive,

(different from relocation test for anterior translation)
 Clinical Examination

Relocation test of Jobe:

Pain in the posterior joint line when
the arm is brought in abduction
external rotation with the patient
supine that is relieved when a
posterior directed force is applied to
the shoulder
MRI findings
Internal Impingement – Bennett’s Lesion
 Differential Diagnosis

• SLAP lesions
 Pain more anterior than Internal Impingement.
 Positive O’Brien test and SLAPrehension test. These
tests are negative for internal impingement.
 Coronal oblique MRI can help

• Isolated posterior labrum tear

 The most difficult to differentiate from internal imp.
 Both posterior pain in the abducted and ext rotated
position.
 Arthroscopy can help
 Conservative Treatment

• Rest (complete stop of throwing is critical)

• Rehabilitation (physical therapy as soon as possible) to
– improve posterior flexibility
– improve dynamic stabilization
– increase strength of rot cuff muscles

• Then gradual return to throwing

• Improvement of throwing technique
• +/- NSAID
• Most athletes return to sport
 Surgical Treatment

• Diagnostic arthroscopy
(other pathology
found…SLAP, biceps
tendonitis, rot cuff tears etc)

• Arthroscopic Debridement
25-85% return to pre-injury
activity => effective ?
 Surgical Treatment

• Open/Arthroscopic Capsulolabral
Reconstruction

– Arthrolysis of posterior capsule tightness

– Repair of SLAP lesions
– Repair of the rot cuff
– Address anterior capsule laxity
(50 - 81% pre-injury level)
 Conclusions

• Internal Impingement is a • Initial treatment:

relatively common problem in • Complete REST +
overhead athletes PHYSIOTHERAPY

• Difficult to treat • If symptoms persists:

• Multiple surgical
• Caused by repetitive contact techniques
between the undersurface of • Repair all lesions if
the rot cuff and possible
posterosuperior glenoid