- Discussion:
- see:
elbow dislocations in children:
- elbow dislocation is the second most common major joint dislocation;
- dislocation is usually closed and posterior;
-
mechanism:
- dislocations of elbow usually result from fall onto extended elbow.
- anatomic morphology of semilunar notch may predispose to elbow dislocation;
- central angle of semilunar notch is sig large in group of pts who had dislocation of the elbow compared to normals;
-
classification:
- dislocations are classified according to direction of dislocation, namely posterior, posterolateral, posteromedial, lateral, medial, or divergent;
- elbow dislocations without fracture are termed "simple." whereas dislocations with frx are termed
complex;
-
dislocation w/ radial head frx: most common complex dislocation;
-
simple dislocation: pathoanatomy:
- rupture of capsule, rupture of
MCL, lateral ligaments, rupture of flexor pronator mass and less commonly, injury to brachialis muscle;
- rupture of brachial artery has been reported;
-
stability of elbow:
- primary stabilizers
-
MCL is the main stabilizer of the elbow joint (provides 54% valgus stability, while osseous articulation provides 33%);
- ulnohumeral articulation
- coronoid: clinical experience suggests 50% intact coronoid requirement for stability with or without ligamentous integrity
- olecranon contribution to stability inversely correlated with resection amount: >30% articular surface of olecranon needed for stability
- secondary stabilizers
- radiohumeral articulation (most important)
- capsule: greatest role in extension of elbow, insignificant role (<10%) in flexion
- musculature (dynamic)
- ref: Morrey BF, An KN: Articular and ligamentous contributions to the stability of the elbow joint. Am J Sports Med 1983;11:315-319.
- Exam:
- vascular injury:
- closed dislocations are rarely assoc w/ vascular injury, whereas open &/or ant dislocations are commonly assoc w/ such injury;
- in open dislocations,
brachial artery is disrupted by forcible hyperextension (
median nerve injury is commonly associated with such injuries);
- references:
-
Closed elbow dislocation and brachial artery damage. [Review]
- neuro injury:
-
neuropraxia is occurs in 20%, usually involving ulnar or median n (
AIN branch);
- ulnar nerve palsy may occur up to 14% of adult elbow dislocations, and the occurance of ulnar nerve palsy is much higher in pediatric
dislocations w/ an associated medial epicondyle frx;
- most neurologic deficits are transient, but entrapment of median nerve w/ elbow joint after manipulation is more common in
pediatric dislocations;
- references:
-
Median nerve palsy after posterolateral elbow dislocation.
- bony displacement:
- when nl elbow is extended, olecranon process & medial & lat form 3 points on straight line, & when nl elbow is flexed to
90 deg in lateral view, olecranon is aligned vertically w/ epicondyles;
- tip of the olecranon is, however, definitely posterior to the plane of the epicondyles;
- in post dislocation, olecranon process is displaced backward from its normal position in relation to humerus, & one can palpate
the concavity of the semilunar notch;
- increasing degree of elbow flexion exaggerates the prominence of the olecranon process
- very important to examine whole upper extremity for evaluation of
essex-lopresti lesion at wrist or associated fractures
- Radiographs:
- it is essential to obtain radiographs both before and after reduction in order to asses for associated fractures (indicating a
complex dislocations);
- note the radial head avulsion frx, seen in this example;
- Reduction of the Posterior Dislocation:
- Post Reduction Radiographs and Assessment of Stability:
- generally the elbow will be stable in 90 deg or more of flexion;
- the question is whether the elbow will be stable upto 30 deg flexion;
- if instability occurs in 30 deg of flexion, then place forearm in maximum pronation which maximizes the
stress on the MCL which reduces the posterolateral subluxation;
- if there is increased stability in pronation, then the elbow should be placed in a cast brace with the elbow in pronation;
- after clinically determining that the reduction will not be lost in 30 deg of flexion, obtain a portable lateral and AP radiograph;
- look for joint widening, joint irregularity, or malalignment;
- in difficult cases, flouroscopy can be used;
- in cases of simple dislocation, persistent instability as the elbow is extended may indicate interposition of soft tissue or an osteochondral fragment;
- Non Operative Treatment:
- stable articulation will allow for early flexion & extension if valgus stress is prevented after reduction;
- no one has demonstrated a benefit from operative repair of
MCL in simple dislocations;
- best Rx results are obtained w/ early protected ROM begun before 2 wks;
- if there is increased stability in pronation, then the elbow should be placed in a cast brace with the elbow in pronation;
- final clinical outcome for simple dislocations of the elbow is dramatically affected by the duration of immobilization;
- recurrent dislocation is unusual;
- mild loss of extension is common, prolonged immobilization over two wks is assoc w/ greater
flexion contracture;
- references:
Simple elbow dislocation among adults: A comparative study of two different methods of treatment.
- Operative Treatment of Simple Dislocations:
- redislocation of elbow w/ passive range of motion or redislocation in plaster implies severe valgus instability w/ rupture of both
MCL & flexor forearm muscles;
- under these circumstances, operative treatment is indicated;
- repair of
MCL may be attempted but is not guaranteed to restore stability;
- consider use of a hinged elbow fixator, which will allow early range of motion as well as stability;
-
arthroscopy: when exam findings unconvincing, possibility of intra-articular lesion, and reveals radiohumeral joint laxity
- Management of Complex Elbow Dislocations:
-
dislocation w/ radial head frx:
- Complications:
- valgus instability:
- patients will show a variable amount of
MCL laxity which correlates with a worse clinical and radiographic result;
- to maximize the stress on the medial collateral ligament, the forearm should be placed in full pronation, which reduces the posterolateral subluxation;
-
posterolateral instability;
-
heterotopic ossfication
- whether or not all patients with simple elbow frx dislocations should receive prophylaxis is a matter of controversy;
- chronic dislocations:
- in some cases, recurrent instability will be due to
posterolateral instability;
- management of untreated posterior dislocations of the elbow three or more wks after injury may require open reduction;
-
posterior approach: w/ lengthening of triceps, removal of fibrous tissue, & possible K-wire stabilization has been recommended.
- in the report by H. Moritomo et al. 1998, the authors discuss reconstruction of the coronoid process (w/ graft taken from the olecranon)
inorder to help block dislocation;
- Reconstruction of the coronoid process for chronic dislocation of the elbow. Use of a graft from the olecranon in two cases.
H. Moritomo et al. JBJS. Vol 80-B. No 3. May 1998. p 490.
Surgical versus non-surgical treatment of ligamentous injuries following dislocation of the elbow joint. A prospective randomized study.
Simple dislocation of the elbow in the adult. Results after closed treatment.
Ligamentous injuries in dislocations of the elbow joint.
Surgical versus nonsurgical treatment of ligamentous injuries following dislocations of the elbow joint.
Posterior dislocation of the elbow.
Posterior dislocation of the elbow in children.
Fractures and dislocations about the elbow in the head-injured adult.
Elbow dislocation in children and adults. A long-term follow-up of conservatively treated patients.
Posterior dislocation of the elbow.
Recurrent dislocation of the elbow.
Dislocations of the elbow and intraarticular fractures.
Elbow subluxation and dislocation. A spectrum of instability.
Morrey BF. Complex instability of the elbow. Instructional Course Lectures 1998;47:157-164.
Surgical treatment of persistent dislocation or subluxation of the ulnohumeral joint after fracture-dislocation of the elbow.
