Lower limbs trauma 2010
first lecture
Dr .Alaa A. Hussein Al-algawy
Traumatic Dislocation of the Hip Joint
Traumatic dislocation of the hip joint may occur with or without fracture of the
acetabulum or the proximal end of the femur. It is most common during the active
years of life and is usually the result of high-energy trauma, unless there is preexisting
disease of the femoral head, acetabulum, or neuromuscular system. The head of the
femur cannot be completely displaced from the normal acetabulum, unless the
ligamentum teres is ruptured or deficient because of some unrelated cause. Traumatic
dislocations are classified according to the direction of displacement of the femoral
head from the acetabulum.
Posterior Hip Dislocation
Usually, the head of the femur is dislocated posterior to the acetabulum when the
thigh is flexed, for example, as may occur in a head-on automobile collision when the
knee is driven violently against the dashboard. Posterior dislocation is also a
complication of hip arthroplasty.
Clinical features :The significant clinical findings are shortening, adduction, and
internal rotation of the extremity. Anteroposterior, lateral and, if fracture of the
acetabulum is demonstrated, oblique radiographic projections (Judet views) are
required.
Common associated injuries : include fractures of the acetabulum or the femoral
head or shaft and sciatic nerve injury. The head of the femur may be displaced
through a tear in the posterior hip joint capsule. The short external rotator muscles of
the femur are commonly lacerated. Fracture of the posterior margin of the acetabulum
can create instability.
Reduction: If the acetabulum is not fractured or if the fragment is small, reduction by
closed manipulation is indicated. General anesthesia provides maximum muscle
relaxation and allows gentle reduction. Reduction should be achieved as soon as
possible, preferably within the first few hours after injury, as the incidence of
avascular necrosis of the femoral head increases with time until reduction. The main
feature of reduction is traction in the line of deformity followed by gentle flexion of
the hip to 90 degrees with stabilization of the pelvis by an assistant. While manual
traction is continued, the hip is gently rotated into internal and then external rotation
to obtain reduction.
The stability of the reduction is evaluated clinically by ranging the extended hip in
abduction and adduction and internal and external rotation. If stable, the same
movements are repeated in 90 degrees of hip flexion. The point of redislocation is
noted, the hip is reduced, and an anteroposterior radiograph of the pelvis is obtained.
Soft tissue or bone fragment interposition will be manifested by widening of the joint
space as compared to the contralateral side.
1
Indication of surgery : Irreducible dislocations, open dislocations, and those that redislocate after reduction despite hip extension and external rotation (usually because
of associated posterior wall fracture of the acetabulum) are indications for immediate
open reduction and internal fixation if necessary. Most authors agree that a widened
joint space on radiograph, despite a stable reduction, is also an indication for
immediate arthrotomy. Others prefer obtaining a CT scan first, to further delineate the
incarcerated fragments and associated injuries before surgery.
Minor fragments of the posterior margin of the acetabulum may be disregarded, but
larger displaced fragments are not usually successfully reduced by closed methods.
Open reduction and internal fixation with screws or plates is indicated.
Post reduction treatment will vary according to the type of initial surgery. A strictly
soft-tissue injury with a stable concentric reduction may be treated with light skin or
skeletal traction for a few days to a week before exercises are begun.
Complications : include infection, avascular necrosis of the femoral head, malunion,
posttraumatic degenerative joint disease, recurrent dislocation, and sciatic nerve
injury. Sciatic nerve injury is present in 10–20% of patients with posterior hip
dislocation. Although usually of the neurapraxia type, these lesions leave permanent
sequelae in about 20% of cases.
Anterior Hip Dislocation :
Anterior dislocation of the hip is rare compared to its posterior counterpart. It usually
occurs when the hip is extended and externally rotated at the time of impact.
Associated fractures of the acetabulum and the femoral head or neck occur rarely.
Usually, the femoral head remains lateral to the obturator externus muscle but can be
found rarely beneath it (obturator dislocation) or under the iliopsoas muscle in contact
with the superior pubic ramus (pubic dislocation).
The hip is classically flexed, abducted, and externally rotated. The femoral head is
palpable anteriorly below the inguinal flexion crease. Anteroposterior and transpelvic
lateral radiographic projections are usually diagnostic.
Closed reduction under general anesthesia is generally successful. Here also the
surgeon must make sure of a concentric reduction comparing both hip joints on the
post reduction anteroposterior radiograph. The patient starts mobilization within a few
days when pain is tolerable. Active and passive hip motion, excluding external
rotation, is encouraged, and the patient is usually fully weight bearing by 4–6 weeks.
Skeletal traction or spica casting may rarely be useful for uncooperative patients.
first lecture
2
Treatment
The injury follows major trauma, so initial treatment is directed at assessment and
resuscitation of the patient. Neurological injuries must be assessed and documented.
The dislocated hip should be reduced as an emergency and other fractures
addressed subsequently.
1. Closed reduction should be performed within 6 hours of the dislocation. This
can sometimes be achieved in the emergency room, with adequate analgesia but
often a full general anesthetic is required. With a posterior dislocation, greater
mechanical advantage for traction can be achieved with the patient on the
operating room floor. If the reduction is stable, 2.5 to 5 kg of skin or skeletal traction
should be applied.
AP X-rays will confirm the reduction, and when there is doubt about the congruity
of the reduction, a CT scan should be obtained.
2. Immediate open reduction is required when the dislocation cannot be
reduced or the hip is grossly unstable. The joint should be opened, the hip reduced
and the rim fracture stabilized.
3. Retained loose fragments should be removed by arthrotomy or hip
arthroscopy. Fragments can abrade the articular surface and accelerate post traumatic
degenerative change.
4. Significant rim fractures require open reduction and internal fixation under
appropriate conditions. Where there is less than one third of the posterior rim
remaining, the hip may be unstable.
5. Mobilization can start after closed or open reduction as soon as pain allows.
patients should start to move the hip early and be mobilized when their pain permits,
usually around 5 to 10 days, with partial weight-bearing for 6 weeks, increasing to
full weight-bearing over the next 6 weeks.
Prognosis:
The prognosis is related to the period of dislocation, velocity of the trauma and
extent of any associated fracture. A simple dislocation carries a better prognosis
than a large rim fracture, and a delay in reducing the hip of greater than 24 hours
carries a poor outcome.
Excellent or good results, in terms of pain, return to function and degenerative
change, can be expected in 7 5% of patients with an anterior dislocation .
Avascular necrosis and post-traumatic osteoarthritis may occur up to 5 years
after a dislocation.
first lecture
3
Complications
1- Avascular necrosis: IO-35% .
2-Post-traumatic osteoarthritis: 20-30%.
3-Heterotopic bone formation: 3%.
4- Sciatic nerve palsy: 10-19%.
HIP FRACTURE
Fractures of the proximal femur involving the intertrochanteric and neck regions of
the femur are very common injuries. They typically occur in elderly female patients.
Anatomy, classification and epidemiology
Fractures of the hip are divided into two main groups depending on their relationship
to the capsule of the hip joint.
1 - Intracapsular fractures
Fractures of the subcapital and mid-cervical region of the femoral neck.
.2- Extracapsular fractures
Fractures at the base of the neck or in the trochanteric region .
The vascular supply of the femoral head is also of paramount importance. There are
three main sources of vascular supply: (1) the retinacular vessels arising from the
lateral femoral circumflex artery and the inferior metaphyseal artery and then running
beneath the synovium along the neck, which they penetrate proximally both anteriorly
and posteriorly; (2) the interosseous circulation crossing the marrow spaces from
distal to proximal; and (3) unreliably, the ligamentum teres artery.
Fractures of the femoral neck always disrupt the interosseous circulation; the femoral
head then relies only on the retinacular arteries, which may also be disrupted or
thrombosed . Secondary avascular necrosis of part or all of the femoral head can
result. the incidence of nonunion is very high .
Intertrochanteric fractures usually do not suffer this same fate. The capsule (and
vessels) are still attached to the proximal fragment after fracture, and thus the blood
supply remains patent.
The demographic features of both injuries are similar - they usually occur in older
female patients. The mean age is 75 years and the female male ratio is 4 to 1.
Dementia or some degree of cognitive impairment is common and typically present in
25-30% of cases. Significant medical comorbidities are present in 70% of patients
Clinical findings:
There is usually a history of a fall. In displaced Intracapsular or Extracapsular
fractures the leg is typically shortened and externally rotated. Neurovascular injury is
very rare, but about 10% of patients will have an additional fracture, usually a
proximal humeral or distal radial fracture.
first lecture
4
Management:
In the past some of these fractures were treated non-operatively in traction, but in
modern orthopaedic practice there is no role for this unless the patient is moribund
on admission and not expected to survive.
Intracapsular fractures
Femoral Neck Fractures
Femoral neck fractures are intracapsular fractures. Because of the already mentioned
unusual vascularization of the femoral head and neck, these fractures are at high risk
of nonunion or avascular necrosis of the femoral head. The incidence of avascular
necrosis increases with the amount of fracture displacement and the amount of time
before the fracture is reduced.
Fractures of the femoral neck occur most commonly in patients over age of 50 . The
involved extremity may be slightly shortened and externally rotated. Hip motion is
painful, except in the rare cases of nondisplaced or impacted fractures, where pain
may be evident only at the extremes of motion. Good quality anteroposterior and
lateral radiographs are mandatory.
Classification
The Garden classification for acute fractures is the most widely used system:
Type 1: Valgus impaction of the femoral head
Type 2: Complete but nondisplaced
Type 3: Complete fracture, displaced less than 50%
Type 4: Complete fracture displaced greater than 50%
This classification is of prognostic value for the incidence of avascular necrosis: The
higher the Garden number, the higher the incidence. The benefits of either skeletal or
skin traction are unclear prior to definitive treatment. Traction may offer comfort in
some patients but do not improve overall outcome.
Undisplaced intracapsular fractures are generally treated by internal fixation using
screws. Although they can be treated non-operatively, 15% will displace and it is
safer to treat these injuries surgically. Avascular necrosis occurs in 5% of cases and
conversion to arthroplasty may be required later if this is symptomatic,
Displaced intracapsular hip fractures are almost always in the subcapital region of the
femoral neck. Reduction and fixation is possible, but there is a high rate of early nonunion and fixation failure. Avascular necrosis affects about 15% of those that do
unite. Overall, 40% of patients treated in this way will require conversion to some
form of hip arthroplasty at a later stage.
first lecture
5
Most surgeons, therefore, choose to treat the majority of these patients with an
arthroplasty in the first instance. Reduction and fixation should be considered in
younger patients (<60 years). However, many younger patients with these injuries
have risk factors that predispose to osteoporosis (alcohol abuse, steroid treatment,
epilepsy treatment, renal or other metabolic bone disease). If risk factors are present
then arthroplasty should be considered
For most displaced intracapsular hip fractures, hip arthroplasty is the treatment
of choice. The choices are either some form of hemi-arthroplasty or a total hip
arthroplasty
Complications
The most common sequelae of femoral neck fractures are loss of reduction with or
without hardware failure, nonunions or malunions, and avascular necrosis of the
femoral head. This latter complication can appear as late as 2 years after injury.
According to different series, the incidence of avascular necrosis for Garden type 1
fractures varies from 0 to 15%, for type 2 fractures 10–25%, for type 3 fractures 25–
50%, and for type 4 fractures 50–100%. Secondary degenerative joint disease appears
somewhat later.
Extracapsular fractures
Extracapsular hip fractures in the trochanteric region of the proximal femur. The
clinical features are the same as for subcapital hip fractures. Characteristically, the
fracture occurs in an elderly female and the leg is shortened and externally rotated at
presentation
Since the blood supply of the femoral head is not endangered, internal fixation is the
treatment of choice. The most commonly used device is a sliding hip screw and plate.
Alternative devices that involve intramedullary fixation are also commonly used,
particularly for subtrochanteric fractures, especially if they extend a long way down
the femoral shaft
The main complications of surgery are failure of fixation (<5%), non-union (1-2%)
and infection (<5%).
Treatment
The aim of treatment is to achieve early mobilization of the patient, avoiding the
attendant complications of prolonged bed rest. Young patients should be treated in
the same manner. Rehydration and urgent medical assessment of all patients is
vital. Surgery should be performed within 48 hours of the fracture, as confusion,
pneumonia, the incidence of pressure sores and the duration of hospital stay all
increase significantly after a period if surgery is further delayed.
first lecture
6
1. Closed treatment, with
skin or skeletal traction for 6-8 weeks will usually
achieve sound union and should be reserved for the 2 or 3% of patients where
surgery is contraindicated or declined.
Undisplaced fractures can be treated with early mobilization and partial
weight-bearing. The fracture should be reassessed regularly with X-rays. Where
pain persists, the fracture displaces or the patient is unable to cooperate with
mobilization, internal fixation should be performed.
2. Internal fixation is
the treatment of choice, followed by early mobilization and
weight-bearing as tolerated. Careful placement of the patient on the fracture table
is essential and an anatomical reduction can often be achieved before opening the
fracture.
A variety of devices may be used a sliding hip screw-plate system a ( dynamic
hip screw) is the most popular.
Short intramedullary devices may be used, but are less popular. Flexible IM
nails, inserted into the femoral neck and head from the condylar region.
Subtrochanteric fractures can be treated with a sliding hip screw or
of an intramedullary device by closed means with sound fixation by locking screws
into the femoral head is preferable.
3. Isolated greater and lesser trochanter fractures
are rare and can usually be
treated symptomatically
Outcome after hip fracture:
Irrespective of the location of the hip fracture, the outcome is frequently poor. This is
more a reflection of the frail medical state of these patients, rather than the nature of
the surgery required. The 1-year mortality rate for all hip fractures is 30%, but in
demented patients it is 50% .
Rehabilitation in a non-acute institution is required in 35-40% of patients. Ultimately
70% of patients return home, but the remainder require some form of residential care.
first lecture
7