•Acute dislocation of elbow occurs frequently accounting for upto28% of all injuries to the elbow, second in frequency only to shoulder dislocation.
•Elbow dislocation usually is a high energy episode usually sustained by active adolescents.
•Ulno humoral articulation is the cornerstone of osseous stability & mobility in flexion & extension plane
•Additional stability to elbow is brought about by locking mechanism of coronoid & olecranon process
•Lateral collateral ligament is the main lateral stabilizer in both flexion and extension and contributes to 14% of varusstability in full extension & 9% of varusstability in 90 degree flexion
•Anterior band of medial collateral ligament provides 55% valgus stability in 90 degree flexion
•Stimson classified elbow dislocations into following types:
1)Proximal radio ulnar joint intact:
A)Posterior dislocation (90%)
-Lateral (more common)
i) Recurrent posterior dislocation
ii) Old unreduced posterior dislocation
B) Anterior dislocation
C) Medial or lateral dislocation
2) Proximal radio ulnar joint displaced:
A) Antero posterior -Radius is anterior Ulna is posterior
B) Transvers -Radius is lateral Ulna is medial
POSTERIOR ELBOW DISLOCATION
•This is most common dislocation of elbow constitutes about 90% of elbow dislocation.
•Posterolateral is more common
Mechanism of injury :
•Commonly caused by fall on outstretched hand.
•So abduction and extension forces generated due to fall will be transmitted to hyperextended elbow leading to rupture of the ulnar collateral ligament.
•Elbow is held in slight flexion and supported with other hand.
•The forearm is shortened with prominence of olecranon and radial head posteriorly. So triangular relationship is lost.
•Neurovascular function is usually intact but needs to be accurately assessed.
•Crepitus or extensive ecchymosis implies a fracture dislocation of elbow.
Radiographic and other imaging studies :
•AP & Lateral Xrays
Special views –
1.Jones view -to visualize posteriormedial degenerative osteophyte and loose bodies in old unreduced dislocation.
2.Medial oblique view -to visualize radial head, coronoid process of ulna and medial epicondyle.
Arthroscopy : To assess ligamental tear and repair, to remove, loose bodies.
MRI, CT: To evaluate for complete or incomplete
Closed reduction :
Elbow should be reduced quickly under short GA
Principle of close reduction :
1)Forearm should be hypersupinatedin slight flexion to dislodge the coronoid process and radial head from their position behind distal humerus.
2) Simultaneously force must be applied proximally along the long axis of the humerus and distally along the long axis of forearm
3) Once it is reduced elbow is flexed to 90°to stabilize reduction.
TECHNIQUES OF REDUCTION:
1) PULLER technique:
In supine position: With elbow flexed to almost 90 a force is applied to the anterior portion of the forearm with one hand while the other hand pulls the forearm distally.
In prone position : Same forces are applied to the proximal portion of the anterior and distal forearm -in this position table provides a counter force against anterior portion of distal humerus.
2) PUSHERS technique:
- Meynand Quingley'smethod :
In this method forearm hangs by the side of the table &
traction is applied to wrist with
other hand olecranon process is pushed downwardsto get reduction.
The patient lies prone on the table & traction is given with one hand over the wrist for few minutes,
as olecranon begins to slip distally, the arm is pushed up with other hand of the physician to get reduction.
ANTERIOR ELBOW DISLOCATION
•Are rare but they are associated with complications such as brachial artery injury
Mechanism of injury : hyperextension of the elbow
Clinical features :
•Elbow is in extension with fullness in the antecubital fossa
•Swelling present due to marked soft tissue injury.
•Severe pain on movement.
•Closed reduction : Reduced under short GA.
With elbow semiflexed, a longitudinal force is applied along the long axis of humerus & at the same time pulling of forearm is necessary to initially dislodge the olecranon.
Once olecranon is distal to humerus, the distal humerus is pushed anteriorly, at the same time proximally directed force is applied along the long axis of forearm.
Finally elbow is immobilized in extension.
•Open reduction :
Is not required generally unless it is a open dislocation or with neurovascular injury or associated with fractures which are interfering with reduction.
MEDIAL OR LATERAL ELBOW DISLOCATION
•These are rare dislocations, lateral is more common then medial which may be incomplete or complete.
•In incomplete lateral dislocation semilunar notch of ulna articulates
with capitillo-trochler groove and radial head
•In complete variety olecranon is totally lateral to the capitulum this gives elbow a markedly widened appearance.
Reduced by giving longitudinal traction along the long axis of humerus to distract elbow and then direct medial or lateral pressure applied over proximal forearm.