The usual story is that the patient visits the emergency
room and comes back to see the doctor because the patient is having constant shoulder
pain and is unable to move the shoulder. When examining the patient, the
patient will have limitation of external rotation of the shoulder. You may be
shown an x-ray, an AP view of the shoulder, and the interpretation of the x-ray
is that the shoulder appears normal. You need to get two x-ray views (orthogonal
views): AP view and axillary view. An AP view x-ray alone will not diagnose
posterior shoulder dislocation. When you have posterior dislocation of the
shoulder, the AP x-ray view will show the classic “lightbulb” humeral head due
to internal rotation of the shoulder.
The humeral head takes on a rounded
appearance. The axillary view x-ray will show dislocation of the shoulder
posteriorly. It is the best view to show the posterior shoulder dislocation. After
reduction, always get an axillary view and check concentric reduction. Locate the
coracoid (anteriorly) and outline it. Locate the acromion (posteriorly). Then locate
the glenoid and determine whether the dislocation is posterior or anterior. In posterior
dislocation of the shoulder, the axillary view will show the humeral head going
posteriorly away from the coracoid and in the direction of the acromion. With posterior
shoulder dislocation, the shoulder is locked in the internal rotation position
with prominence of the posterior shoulder, prominence of the coracoid process,
and flattening of the anterior shoulder. Posterior shoulder dislocation may be
associated with fracture of the lesser tuberosity. 50% of posterior shoulder
dislocations will have a Reverse Hill-sachs lesion or impaction fracture next
to the lesser tuberosity. When you examine the patient and you see limitation
of the range of motion, especially external rotation of the shoulder, you may
think it is adhesive capsulitis (frozen shoulder). Frozen shoulder can start by
limiting the external rotation, however it is usually a global restriction of
the range of motion.
Posterior dislocation of the shoulder is rare (about 5%)
and it is usually stable after reduction if no fracture is present. Posterior dislocation
of the shoulder usually occurs after seizures or electric shock. Why is it that
dislocation of the shoulder most commonly occurs as a posterior shoulder
dislocation with seizures and electric shock? This is a controversial subject. Some
physicians believe that this is due to the fact that the shoulder internal rotator
muscles (pectoralis major, latissimus dorsi, and subscapularis) are stronger
than the external rotator muscles. Up to 50% of posterior dislocations of the
shoulder can go undiagnosed when the patient is examined in the emergency room,
especially if dislocation results from seizures. If posterior dislocation of
the shoulder occurs due to seizures, the patient should be examined carefully
and neurology consult should be done to control the patient’s seizures. Any future
treatment of posterior dislocation of the shoulder may fail due to lack of
controlling seizures. Closed reduction is not difficult in the acute setting and
can be done up to 3 months. Instability is rare with absence of fracture. Immobilize
the arm in neutral rotation with the elbow at the side and posterior to the
plane of the body. Impaction less than 20%, do closed reduction and immobilize
in external rotation. Open reduction is done when posterior dislocation is
chronic or locked. In locked posterior dislocation, the deltopectoral approach
to the shoulder is usually used. If the defect is between 20%-40%, transpose the
lesser tuberosity or the subscapularis tendon into the defect. More than 45%
defect or if the dislocation is more than 6 months, do arthroplasty and place
the prosthesis in less retroversion.
With elbow dislocations, recognize the terrible triad: elbow
dislocation, radial head fracture, and coronoid fracture. The terrible triad is
not a simple elbow dislocation; it is a complex elbow dislocation. In addition
to these three injuries of the elbow, there is always a tear of the lateral
ulnar collateral ligament. The treatment usually is reduction and splinting of
the elbow.
This cannot be the definitive treatment; it is the initial
treatment. If no surgery is done, you will have recurrent dislocation of the
elbow. You need to do surgery for reduction and fixation of the fractures and
also to restore the elbow stability. This injury is unstable. Simple reduction
and splinting is not going to work for this injury. You have to recognize the terrible
triad which means surgery. There are multiple types of elbow dislocation based
on the position of the olecranon relative to the humerus. The most common type
of elbow dislocation is the posterolateral type. There are two basic types of
elbow dislocations: simple and complex. Simple elbow dislocations have no
fracture seen, and are usually a ligamentous injury. Complex elbow dislocations
have associated fractures in addition to the ligamentous injury. With any elbow
dislocation, you need to check the shoulder and the wrist for injuries and
fractures because it can occur in up to 15%. When you have a simple dislocation
of the elbow, you need to reduce it and then check the range of stability of
the elbow. If you find that the elbow is stable with range of motion, then you
will do a short period of immobilization with a posterior splint for
approximately one week with the elbow in about 90 degrees of flexion. Then start
active range of motion of the elbow. Recurrence of the dislocation is rare
(less than 1%). If you keep the elbow immobilized more than 3 weeks, there will
be severe stiffness of the elbow. Surgery should be done if the dislocation is
irreducible, if there is associated fracture, or if you are unable to maintain
stability of the elbow. After immobilization and early range of motion of the
elbow, you will see the patient and do follow up x-rays to check joint
congruity and to make sure that the elbow reduction is maintained. To treat the
terrible triad, you should initially do a closed reduction. Open reduction and
internal fixation of the coronoid (if possible), of the radial head or excise
the radial head with radial head arthroplasty if the radial head is
unreconstructable. In addition, you will do lateral ulnar collateral ligament (LUCL)
repair. Never excise the radial head alone in this situation. For an elbow
dislocation with olecranon fracture, do open reduction and plate fixation.
K-wires and tension band is not strong enough to hold the fracture and
stabilize the elbow at the same time. For an elbow dislocation with a radial
head fracture, do fixation or replacement of the radial head (never do excision
of the radial head alone in this situation). The LUCL is the most important
lesion in recurrence or persistence of instability of the elbow following
simple elbow dislocation.
The injury progresses from lateral to medial. The lateral
collateral ligament fails first, and it avulses proximally at the lateral
epicondyle. The medial collateral ligament (MCL) fails last. In varus
posteromedial rotary instability, there is an elbow injury plus LUCL tear, plus
coronoid fracture which involves the medial facet of the coronoid. Treatment for
chronic dislocation is open reduction capsular releases with hinge external
fixation and early range of motion. Loss of terminal extension is a
complication of elbow dislocation. Usually for decreased range of motion of the
elbow, you will do static progressive splinting between 6-10 weeks. No manipulation
of the elbow is done, which is different from the knee after total knee
replacement, where you can do manipulation up to three months. With heterotopic
ossification, do excision. Remove the myositis and excise the posterior part of
the MCL to allow more flexion. To be functional, the range of motion of the
elbow should be between 30-130 degrees. Some physicians suggest that if the
flexion is less than 100, you will do release of the posterior bundle of the
MCL in addition to release of the ulnar nerve. If you want more flexion of the elbow,
excise the posterior part of the MCL.
Congenital Dislocation of the knee is rare and may occur due
to a contracture of the quadriceps. This condition usually occurs in patients
with myelo, arthrogryposis, or Larsen’s syndrome. The patient with a congenital
dislocation of the knee may have developmental dysplasia of the hip (DDH) and
club foot. On examination, the patient will have a hyperextended knee at birth.
They may have their foot placed against their face and there will be limited
flexion at the knee. The patient may have a dimple or skin crease at the
anterior aspect of the knee. You must examine the hip to rule out ipsilateral
hip dislocation. 50% or more patients will have hip dysplasia. The etiology is
not known; however, it could be due to fetal positioning or congenital absence
of the cruciate.
There are grades, or a spectrum, for this deformity. Grade I
deformities are referred to as Severe Genu Recurvatum, and the knee is
hyperextended. If the range of passive flexion is more than 90°, it is
considered to be a simple recurvatum. Grade II deformities are identified by
subluxation with a range of 30-90° in passive flexion. Grade III deformities
are complete dislocations with a range of passive flexion being less than 30°.
Congenital dislocation of the knee will take priority over
treatment of hip dysplasia or club foot. The Pavlik harness and club foot cast
will require knee flexion, so the physician will need to treat the knee
dislocation first. With Grade I deformities, the initial treatment will be
stretching of the knee and serial casting with the knee in flexion. In serial
stretching and casting, the goal is to obtain at least 90° of flexion and
reduction of the deformity over the course of several weeks. The physician
should avoid pseudo-correction through an iatrogenic fracture of the proximal
tibial physis. The prognosis is usually good if reduction is achieved without
surgery. With Grade II deformities, if the infant is less than 1 month old, you
will do serial casting first followed by percutaneous quadriceps recession,
especially if the flexion is less than 90°. In Grade III deformities, a V-Y
quadricepsplasty with above the knee cast is done in Grade III (frank dislocation),
especially if nonsurgical treatment fails to reduce the tibia on the femur. The
result of open surgery is better when it is done in children younger than 6
months. In general, open reduction is reserved for children who did not respond
to stretching and cast immobilization. It is important that the hip dysplasia
is recognized and the knee dislocation is corrected early. This will help in
early reduction of the hip.
An Elbow dislocation occurs when the radius and ulna bones
of the forearm move out of place from the humerus bone of the upper arm. There
are two basic types of elbow dislocations:
Simple
No fracture of the bones around the elbow
joint
Usually ligamentous injury
Complex
Fracture has occurred along with ligamentous
injury
Simple elbow dislocations typically occur when the patient
falls onto an outstretched hand. Injury progression from lateral to medial in
most patients. Posterolateral simple dislocations are the most common, occurring
approximately 90% of the time.
The proximal ulna and radius are displaced
posterolaterally relative to the distal humerus. Postemedial dislocations occur
at the proximal ulna and radius and are displaced posteromedially relative to
the distal humerus. In medial dislocations, the proximal ulna and radius are
displaced medially relative to the distal humerus. With lateral dislocations,
the proximal ulna and radius are displaced laterally relative to the distal
humerus. Anterior dislocations are rare, as they result from a direct force
applied to the posterior aspect of the forearm with the elbow in a flexed
position. Anterior dislocations occur when the proximal ulna and radius are
displaced anteriorly relative to the distal humerus. If stable, simple acute
fractures can be treated with a closed reduction and a splint for two to three
days (no more than two weeks) in addition to range-of-motion exercises and
physical therapy. Unstable simple fractures are rare, but can be stabilized by
ligament repair and/or by the use of an external fixator or cross pinning of
the joint in the elderly.
Chronic Elbow dislocations will need to be treated with an
open reduction and external fixator and is usually hinged. Recurrent elbow
dislocations (diagnosed by pivot shift) occurs due to a deficiency of the
lateral collateral ligament and is treated by a reconstruction of the
ulnohumeral ligament with a tendon graft.
Hip dislocations can occur posteriorly or anteriorly;
however, any type of hip dislocation is considered an emergency.
Posterior hip dislocations are more common and the lower
limb will be flexed, adducted, and internally rotated. Posterior dislocations
are frequently caused by dashboard injuries. The impact with the car dashboard
drives the femoral head backwards out of the acetabulum. The physician will
want to observe sciatic nerve function and examine the knee to rule out a PCL
injury as well. Weakness of the ankle and toe dorsiflexion due to an injury to
the peroneal division of the sciatic nerve may result in foot drop. The patient
will also be unable to dorsiflex the ankle.
Anterior hip dislocation is rare. Superior Anterior hip
dislocation results from the lower limb being extended, abducted, and
externally rotated. Inferior Anterior Hip Dislocations (obturator type) results
from the lower limb being flexed, abducted, and externally rotated.
An emergency reduction of dislocations is needed in less
than 8 hours of the injury. An urgent reduction is mandatory to avoid avascular
necrosis and interruption of the blood supply, which leads to a collapse of the
femoral head. AVN is the death of a segment of bone.
Treatment
A CT scan should be obtained after reduction to evaluate the
presence of fragments in the joint and access stability of the joint. Hip joint
dislocations may be associated with acetabular or femoral head fractures (Pipkin).
An urgent closed reduction of the hip dislocation followed by stabilization of
either of the fractures if needed according to the protocols.
Proximal interphalangeal (PIP) dorsal fracture dislocations
can be challenging in management. In PIP dorsal fracture dislocations, there
is an involvement of the articular surfaces of the joint. These injuries are the
most disabling PIP joint injuries. A reduction of the middle phalanx on the
condyles of the proximal phalanx is the primary goal of treatment. The patient
frequently presents with a chronic dorsal subluxation due to delay in seeking
treatment or from failed treatment.
85% of motion for grasping objects occurs at the PIP joint.
The PIP joint has the largest arc of motion (120 degrees) of the three joints
in each digit.
There are three different types of injury:
Hyperextension
Impact Shear
Pylon
In cases of Hyperextension injuries, the size of the
fragment can range from a small piece of bone, up to 30% of the joint surface
with minimal comminution (usually stable).In order to provide accurate treatment, the physician will want to test
the stability of the fracture and apply a dorsal blocking splint. It is
important to observe the lateral view for any subluxation.
Impaction/Shear injuries are produced by an axial load
applied to a slightly extended or flexed PIP joint. The middle phalanx is
driven over the head of the proximal phalanx with comminution and impaction of
the base of the middle phalanx. These injuries are characterized by the loss of
the volar plate tether. A 50% loss of the palmar of the middle phalanx base
will make the PIP joint unstable. The extensor tendon and superficialis tendon
will aggravate the dorsal subluxation. Splints will be inadequate if the injury
is not stable. Treatment will include skeletal traction and early range of
motion. An open reduction and internal fixation may be necessary if the
fragment is large enough. A Palmar Plate Arthroplasty may be considered to
advance the palmar plate into the defect. This procedure will support the
palmar plate by filling the defect behind it with fracture chips, bone graft,
or by a superficialis slip. Chronic impaction/shear cases are a difficult
problem and can be treated with an arthrodesis or volar plate arthroplasty.
A pylon fracture results from an axial force that fractures
the volar and dorsal articular surfaces with impaction on the central part. A
pylon fracture is not a true fracture dislocation and will not have a good
outcome. Dynamic external traction should be done in order to help in
ligamentotaxis. Early range of motion is important for remodeling of the joint.
Classification of a PIP Dorsal Fracture Dislocation will
depend on the degree of involvement of the articular surface.
Type I (stable) <30%
Type II (tenuous)= 30-50%
Type III (unstable) > 50%
Treatment will consist of a Dorsal Extension Blocking Splint
if the PIP can be reduced in less than 30% of flexion. If less than 40%, the
joint involved and stable. For Type I and Type II fractures, decrease the
flexion gradually every week. Type III fractures will require ORIF, volar plate
arthroplasty, or hemi-hamate graft (if >40% joint involved and unstable).
With a Hemi-Hamate Graft, the damaged palmar lip of the
middle phalanx with a size matched portion of the hamate bone obtained from its
distal dorsal articular surface between the 4th and 5th
metacarpals. It restores both articular congruity and osseous stability.
Extension block pinning is probably a helpful technique. Treatment must provide
stable reduction to allow for early mobilization.
Stability of the reduction depends on the size of the
avulsed fragment and the amount of ligament remaining attached to the middle
phalanx. If less than 40% of the articular segment is avulsed, some of the
collateral ligament will be intact. This will keep the reduction stable. If
more than 40% of the articular segment has avulsed, only very little or none of
the ligament will remain attached to the base of the middle phalanx, rendering
the reduction unstable.
Recognizing Subluxation
AP and lateral x-rays are necessary for diagnosis. An AP
view will help to recognize impaction fractures.Subluxation can be missed on x-rays. The
physician will want to look for the characteristic “V” sign of diverging joint
surfaces, which indicates injury and subluxation.
If a reduction of the avulsion fracture is achieved with
less than a 30 degree bend, nonoperative treatment is a good choice. However,
if it takes more than 30 degrees of flexion to reduce the fragment, this may be
an indication for surgery.
