Transcript Biomechanics of fracture fixation

Anatomy, diagnosis and
classification of sports injuries in the
shoulder
Mr. Nnamdi Obi
Specialist registrar
United Kingdom
Objectives
• Review anatomy of the shoulder
• Review history and examination
• Acute traumatic shoulder instability
Introduction
• Instability
– Glenohumeral dislocation
• SLAP tears
– ACJ dislocation
30 YO male,Professional Rugby payer,
first episode
Anatomy
• Synovial ball and socket
joint
• Articular surface covered
with hyaline cartilage
• Glenoid cavity deepened
by labrum
• Articulations
Rotator cuff
• Supraspinatus
• Infraspinatus
• Teres Minor
• Subscapularis
Ligaments
• Glenohumeral
– Superior Glenohumeral ligament
– Middle Glenohumeral Ligament
– Inferior Glenohumeral Ligament
• Shoulder girdle
– Coraco clavicular
– ACJ proper
– Acromioclavicular
Biomechanics
Static restraints
Dynamic restraints
• Glenoid labrum
• Rotator cuff muscles
• Articular version +
conformity
• Biceps tendon
• Glenohumeral ligaments
• Scapular stabilizers
• Negative intra-articular
pressure
• Neuromuscular factors
History
(Acute traumatic instability)
• Age
• Mechanism
• Traumatic
• Atraumatic
• Chronicity
– Ease of dislocation
• Expectations
• Return to play
Examination
• Acutely
– Pain limits most
– Pre and post axillary nerve function
• Sensory
• Motor
• Delayed
• Hyperlaxity – predisposing
• Provocative tests
• Labral pathology (SLAP tear)
Sulcus sign
Apprehension
Relocation test
Labrum (SLAP)
• O’Brien’s
Labrum
• Load & Shift
Special investigations
• Bones
• Soft tissues
– Glenoid
– Head humerus
– Rotator cuff
– Labrum
Ultrasound – no labrum
MRI
X Ray
CT scan
CT arthrogram
MRI arthrogram
Lateral radiographs
• Posterior oblique scapular projection (“Neer lateral”, Neer 1970)
– Produces considerable image overlap
• Transthoracic (Vastamaki and Solonen 1980)
– Image overlap
• Axial (Warrick 1965)
– Requires shoulder abduction
• Modified axial (Rockwood 1984)
– Some shoulder abduction
• Velpeau lateral (Wallace and Hellier 1983)
– Patient needs to sit up
• Apical oblique (Garth, Slappey and Ochs 1984)
This is posterior dislocation
But outlines glenoid and humeral head
J Bone Joint Surg [Br] l988;70-B:457-60.
Almost normal AP
Axial view
Small Hills sachs
Anterior glenoid Fine
Same patient Apical oblique
Large Hills sachs
Blunting anterior glenoid
Bone loss
- Plain x-ray
- CT
- CT recon
30 YO male, football, first episode
Treatment
How long ?
• MRI study
– IR Labrum off glenoid
– ER tension rests on glenoid
• Randomized 40 pts
– Sling IR Vs ER
– Recurrence
• IR 6/20, 30%
• ER 0/20
J Shoulder Elbow Surg 2003;12: 413-15
JBJS – B VOL. 91-B, No. 7, JULY 2009
• Premise
– Younger = recurrent instability = immobilize longer
– Older = stiffness = mobilize sooner
• No benefit to immobilization in internal rotation > 1 week in pts
under 30 yrs of age
• Age of less than thirty years at time of injury predicts increased
recurrence.
• Best available evidence does show a clinical benefit to treatment in
external rotation over conventional sling immobilization, but this
advantage did not reach significance
• BUT most ITOI
J Bone Joint Surg Am. 2010;92:2924-33
Take Home
• Reduce
• Sling comfort
• Discard in 1 week
• Physiotherapy, strengthen dynamic stabilizers
• Under 30 years, continue contact sport
• Counsel recurrence rate
• Consider surgery following first dislocation
SLAP Lesions
• May be associated with
dislocation but commonly
due to pull on the arm,
weightlifting, throwing,
tackling
• Symptoms – clicking, pain
with overhead activities
• Clinically – pain with
eccentric biceps loading (e.g.
going down on bench press)
SLAP lesion classification
Acromioclavicular joint (ACJ) injuries
• Usually injured by a
direct fall onto the point
of the shoulder
• Scapular forced
downwards
• Clinically, lateral end of
clavicle prominent
30 YO rugby player again
Classification of ACJ Injuries
(Rockwood)
Treatment
• Non Operative
– Grade 1-3
• Operative
– Grade 4-6
Conclusions
• Acute instability common in athletes
– Glenohumeral
– ACJ
• High level of function
• Early return to play
• Axillary or modified axillary view
– Apical oblique
References
• Websites:
– https://www.shoulderdoc.co.uk
– https://www.orthobullets.com
The End
Email: [email protected]