Orthopedics 5th year, 3rd lecture (Dr. Ali A.Nabi)

Injuries of the hip

Anatomy

• Hip joint is• Ball and socket joint.• Femoral head: slightly asymmetric, forms 2/3 sphere.• Acetabulum: inverted “U” shaped articular surface.• Ligamentum teres, with artery to femoral head, passes

through middle of inverted “U”.

Joint Contact Area

40% of femoral head is in contact with acetabular articular cartilage.

10% of femoral head is in contact with labrum.

Acetabular Labrum

is Strong fibrous ring Increases femoral head coverage Contributes to hip joint stability.

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 Allows muscle relaxation with standing

Femoral Neck Anteversion

Averages 7° in Caucasian males. Slightly higher in females. Oriental males and females have been noted

to have anteversion of 14° and 16° respectively.

Femoral Neck Anteversion

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.

Blood Supply to Femoral Head

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.Perforate bone just distal to articular cartilage.

Highly susceptible to injury with hip dislocation.

Blood Supply to Femoral Head

Dislocation of the hip

Almost always due to high-energy trauma. Most commonly in MVAs. Can also occur in pedestrian-MVAs. falls from heights. industrial accidents. sporting injuries.

Dislocation of the hip

Hip dislocation classified according to the direction of dislocation

1. posterior hip dislocation.

2. anterior hip dislocation.

3. central hip dilocatrion.

Posterior hip dislocation

Posterior hip dislocation

four out of five traumatic hip dislocations are posterior.

Generally results from axial load applied to femur, while hip is flexed.

Most commonly caused by impact of dashboard on knee.

Sometimes the dislocation associated with fracture of piece from acetabulum or femoral head and this calles fracture-dislocation.

Posterior hip dislocation

Type of Posterior Dislocation depends on:

1. Direction of applied force.

2. Position of hip.

3. Strength of patient’s

bone.

Posterior hip dislocation

Hip Position vs. Type of Posterior Dislocation

1. Abduction: fracture-dislocation

2. Adduction: pure dislocation

3. Extension: femoral head fracture- dislocation.

4. Flexion: pure dislocation.

Effect of Dislocation on Femoral Head Circulation

When capsule tears, ascending cervical branches are torn or stretched. Artery of ligamentum teres is torn. Some ascending cervical branches may remain

kinked or compressed until the hip is reduced. Thus, early reduction of the dislocated hip can

improve blood flow to femoral head, otherwise avascular necrosis of the femoral head will take place.

Associated Injuries

Mechanism: high-energy trauma Thus, associated injuries are common:

1. Head and facial injuries

2. Chest injuries

3. Intra-abdominal injuries

Associated Injuries

4. Extremity fractures and dislocations5. Contusions of distal femur6. Patella fractures7. Foot fractures, if knee extended8. Sciatic nerve injuries occur in 10% of hip

dislocations. Most commonly, these resolve with reduction of hip and passage of time.

Associated Injuries

Associated Injuries

Classification

Thomas and Epstein Classification of Hip Dislocations

Most well-known1. Type I Pure dislocation with at most a small

posterior wall fragment.2. Type II Dislocation with large posterior wall

fragment.3. Type III Dislocation with comminuted posterior wall.4. Type IV Dislocation with “acetabular floor” fracture.5. Type V Dislocation with femoral head fracture.

Clinical features

1. H/O Significant trauma, usually MVA.2. Awake, alert patients have severe pain in

hip region.3. Physical Examination: Classical

Appearance of Posterior Dislocation:4. the leg is short, hip is slightly flexed,

internally rotated and adducted.

Clinical features

Clinical features

5. Unclassical presentation (posture) if:

a. femoral head or neck fracture

b. femoral shaft fracture.

In which the golden rule to x-ray the pelvis in every fracture femur to detect missed hip and pelvic injury.

– Pain to palpation of hip.– Pain with attempted motion of hip.– Neurological examination for sciatic nerve injury.

Imaging

Radiographs: AP Pelvis X-Ray Should allow diagnosis and show

1. direction of dislocation.2. Femoral head not centered in

acetabulum.3. Femoral head appears larger (anterior) or

smaller (posterior).4. Usually provides enough information to

proceed with closed reduction.

Imaging

Imaging

CT Scan Most helpful after hip reduction.Reveals:

1. Non-displaced fractures.

2. Congruity of reduction.

3. Intra-articular fragments.

4. Size of bony fragments.

CT scan

Imaging

MRI Scan

Will reveal labral tear and soft-tissue anatomy.

MRI

Treatment

Dislocated hip is a surgical emergency. Goal is to reduce risk of avasular necrosis of

femoral head. Emergent Reduction will1. Allows restoration of flow through occluded or

compressed vessels.2. Literature supports decreased AVN with earlier

reduction.3. Requires proper anesthesia usually GA.4. Requires “team” (i.e. more than one person).

Treatment

Allis Maneuver Assistant: Stabilizes pelvis Posterior-directed force on both ASIS’s Surgeon: Stands on stretcher Gently flexes hip to 90° Applies progressively increasing traction to the

extremity Applies adduction with internal rotation Reduction can often be seen and felt

Treatment

Nonoperative Treatment If hip stable after reduction, and reduction congruent. Precautions (No Adduction, Internal Rotation). No flexion > 60°. Early mobilization. Apply skeletal traction for 3 weeks and another

3weeks patient allow to partial weight bearing with crutches.

Repeat x-rays before allowing weight-bearing.

Treatment

Indications for Operative Treatment

1. Irreducible hip dislocation

2. Hip dislocation with femoral neck fracture

3. Incarcerated fragment in joint

4. Incongruent reduction

5. Unstable hip after reduction.

Complications

Early

1. sciatic nerve injury.

2. vascular injury.

3. associated fractured femoral shaft and other associated injuries.

Complications

Late

1. avascular necrosis of the femoral head. If the reduction delayed for few hours the risk of AVN increase up to 40%. The features will appear in the x-ray after 6weeks.

2. myoscitis ossificans.

3. unreduced dislocation.

4. osteoarthritis which may due toa. articular cartilage damage.

b. Retained fragment in the joint.

c. Avascular necrosis of the femoral head.