This lecture describes the dislocation of hip and fracture of femur, along with their types, mechanism involved, effects, evaluation and treatment.
Outine of Lecture
Dislocation of hip and Fractures of the femur
Hip Joint
Ball and socket joint.
Ligamentum teres, with artery to femoral head, passes through middle of inverted “U”.
Hip Joint Capsule
Extends from intertrochanteric ridge of proximal femur to bony perimeter of acetabulum
Has several thick bands of fibrous tissue
Iliofemoral ligament
Upside-down “Y”
Blocks hip extension
Blood Supply to Femoral Head
Artery of Ligamentum Teres
Most important in children.
Its contribution decreases with age, and is probably insignificant in elderly patients.
2. Ascending Cervical Branches
Arise from ring at base of neck.
Ring is formed by branches of medial and lateral circumflex femoral arteries.
Penetrate capsule near its femoral attachment and ascend along neck.
Highly susceptible to injury with hip dislocation and Fr of neck.
Sciatic Nerve
Passes posterior to posterior wall of acetabulum.
Sciatic nerve injuries occur in 10% of hip dislocations.
Classification of hip dislocation
Anterior Hip Dislocation
Posterior Hip Dislocation
On X-Ray: Femoral head appears larger (anterior) or smaller (posterior).
Hip Dislocation: Mechanism of Injury
Almost always due to high-energy trauma.
Most commonly involve unrestrained occupants in MVAs.
Can also occur in pedestrian-MVAs, falls from heights, industrial accidents and sporting injuries.
Mechanism of Posterior Dislocation
Generally results while hip is flexed.
Most commonly caused by impact of dashboard on knee.
Mechanism of Anterior Dislocation
Extreme abduction with external rotation of hip.
Anterior hip capsule is torn or avulsed.
Femoral head is levered out anteriorly.
Effect of Dislocation on Femoral Head Circulation
Artery of ligamentum teres is torn.
Some ascending cervical branches may remain kinked or compressed until the hip is reduced.
Sciatic nerve may get direct or comperession injury.
Thus, early reduction of the dislocated hip can improve blood flow to femoral head and reduce the chances of permanent demage to sciatic nerve.
Associated Injuries with femur fractures and dislocations
Mechanism: high-energy, unrestrained occupants
Thus, associated injuries are common:
Head and facial injuries
Chest injuries
Intra-abdominal injuries
Evaluation: History
Significant trauma, usually MVA.
Awake, alert patients have severe pain in hip region.
Physical Examination: Classical Appearance Posterior Dislocation
Hip flexed, internally rotated, adducted.
Physical Examination: Classical Appearance Anterior Dislocation:
Extreme external rotation, less-pronounced abduction and flexion.
Unclassical presentation if:
femoral head or neck fracture
femoral shaft fracture
Physical Examination
Pain to palpation of hip.
Pain with attempted motion of hip.
Possible neurological impairment:
Thorough exam essential!
Radiographs: AP Pelvis X-Ray
Should allow diagnosis and show direction of dislocation.
Femoral head not centered in acetabulum.
Femoral head appears larger (anterior) or smaller (posterior).
Clinical Management:
Treatment
Dislocated hip is an emergency.
Goal is to reduce risk of AVN to the head.
Evaluation and treatment must be prompt.
Reduction
Allows restoration of flow through occluded or compressed vessels.
Requires proper anesthesia.
Requires “team” (i.e. more than one person).
Complications of Hip Dislocation
-Avascular Necrosis (AVN): 1-20%
Results are best if hip reduced within six hours.
-Post-traumatic Osteoarthritis
-Recurrent Dislocation—Rare
-Sciatic Nerve Injury—10%
Fractures of the Femur
Proximal femur (Neck)
Shaft of femur
Distal femur
Fractures of the proximal femur—Neck of femur
Femoral neck fractures that are intracapsular may threaten blood supply to the femoral head:
-the cervical vessels in the retinaculum of the joint capsule – usually damaged if the fracture is displaced
-intramedullary vessels – always torn
-from the ligamentum teres – usually contributes minimally in the elderly and not uncommonly, may be non-existent
Incidence and Mechanism
The fracture of the neck of femur is common in the elderly. It does occur occasionally in young adults and even in children. It occurs more frequently in women.
The fracture may result either from rotation violence at the hip due to tripping over something on the floor and falling or a direct violence over the lateral aspect of the hip by a fall on the side.
Types/Classification
1. Intracapsular Fractures
These are diveded according to the level of the fracture line in the neck as follows.
1) Subcapital
2) Transcervical
3) Basal
the proximal fragment often loses part of its blood supply and hence, the union of this fracture is difficult.
2. Extracapsular Fractures
- These are all grouped as Trochanteric fractures of various types.
Intracapsular Fractures
Clinical Features
The patient is usually an elderly person with a history of a fall and inability to walk.
On inspection, the injured leg lies in a position of external rotation and there is shortening of the leg.
Radiological Features
An anteroposterior view of the whole pelvis to show both the hips must be taken. It shows the level and the type of fracture.
CT
MRI
Management
Conservative Treatment ?
Fractures at this level have a poor capacity for union due to the following factors.
a) interference with the blood supply to the proximal fragment.
b) difficulty in controlling the small proximal fragment.
c) the lack of organisation of the fracture haematoma due to the presence of the synovial fluid.
Surgical Treatment
Two essential principles to be followed in the surgical management of this fracture are
– perfect anatomical reduction.
rigid internal fixation.
Extra Capsular Fracture neck of femur
These are also called low fractures
In this group, the blood supply to the proximal fragment is not interfered with and there is a greater area of contact between the two fragments; hence the fractures unite easily.
These fractures occur in the elderly and the nature of the violence is the same as in the intracapsular fracture.
Management
The principle of the treatment is reduction of the fracture and maintenance of the fragments in good position till union occurs.
Conservative Treatment
This consists of the application of continuous skeletal traction. The fracture unites in about 12 weeks.
Operative Treatment
This consists of manipulative reduction and internal fixation. The internal fixation is done by a nail plate as shown in the figure.
Femoral Shaft Fractures
Common injury due to major violent trauma
1 femur fracture/ 10,000 people
More common in people < 25 yrs or >65 yrs
Femur fracture leads to reduced activity for 107 days, the average length of hospital stay is 25 days
Motor vehicle, motorcycle, auto-pedestrian, aircraft, and gunshot wound accidents are most frequent causes
Anatomy
Long tubular bone, anterior bow, flair at femoral condyles
Blood supply
Metaphyseal vessels
Single nutrient artery in diaphysis enters through the linea aspera
Nutrient artery communicates with medullary arteries in intramedullary canal
Medullary arteries supply 2/3 of endosteal blood supply
Management of fracture shaft of femur
Management of the trauma—A B C D—upto 3 Liters of blood may be lost in fracture of the shaft of femur!
Conservative—with traction to immobilize the fracture (Prolonged treatment and poor results.)
Surgical fixation of the fracture.
Femur Fractures
Traction splint for initial reduction of femur fractures prior to OR or skeletal traction
Open Reduction with Internal Fixation
External Fixator for Femoral Shaft Fracture
Femur Fracture
Complications
Hardware failure
Nonunion – less than 1-2%
Malunion – shortening, malrotation, angulation
Infection
Neurologic, vascular injury
Heterotopic ossification
