12 Pediatric Hip Fractures
Proximal Femur Fractures
I. Comprise 1 to 15% of pediatric pelvic fractures. 3
II. Triradiate cartilage injuries (below age 12–14 years) can cause growth arrest and deformities.
III. Often lower energy than adult fractures.
IV. Associated with femoral head fractures and dislocations.
Pelvic Ring Fractures 4
I. Result of high-energy trauma
II. Commonly motor vehicle collision or automobile–pedestrian collision.
III. Differences from adult fractures:
Lateral compression injuries greater than anteroposterior (AP) injuries.
Higher rate of single ring break than adults.
More robust and absorbent cartilage.
Sacroiliac (SI) joint and pubic symphysis are more elastic:
Different injury patterns.
Prior to triradiate closure: bone weaker than ligament, resulting in isolated pubic rami or iliac wing fracture, rather than pelvic ring disruption.
Thickened periosteum stabilizes fractures.
Lower rate of hemorrhage:
Smaller blood vessels.
Higher capacity for vasoconstriction.
Lower likelihood of “open book” injuries.
I. Result of low-energy trauma.
II. Tendon is disrupted from origin or insertion during explosive exercises:
Eccentric contraction of muscle causing traction injury to cartilaginous apophysis.
III. Multiple origins/insertions ( Fig. 12.1 ):
Ischial tuberosity avulsion: hamstring (semimembranosus superolaterally and conjoint semitendinosus/biceps femoris inferomedially) or adductors.
Anterior inferior iliac spine (AIIS) avulsion: direct head of the rectus femoris.
Anterior superior iliac spine (ASIS) avulsion: sartorius, tensor fascia lata, and inguinal ligament.
Lesser trochanter avulsion: iliopsoas.
Iliac crest avulsion: abdominal musculature; also crest apophysitis is a repetitive overuse traction injury; differentiate per Risser’s staging (U.S. system):
Stage 0: no ossification of apophysis.
Stage 1: most anterior one-fourth of apophysis ossified.
Stage 2: most anterior half of apophysis ossified.
Stage 3: most anterior three-fourths of apophysis ossified.
Stage 4: apophysis ossified, but not yet fused to the iliac wing.
Stage 5: completely ossified apophysis fuses to the iliac wing.
Greater trochanter avulsion: hip abductors.
Metaphyseal vessels originating from the medial and lateral femoral circumflex arteries 10 :
Transverse femoral physis and supply the proximal epiphysis.
Artery of ligamentum teres.
Age older than 2 years 10 :
Cartilaginous physis of the proximal femur is barrier to the femoral head blood flow.
Main blood supply is via the lateral epiphyseal vessels from the medial femoral circumflex artery:
Posterosuperior and posteroinferior epiphyseal vessels.
Lie on the femoral neck.
Vulnerable to injury with fracture.
Artery of the ligamentum teres diminishes.
Lateral femoral circumflex artery regresses by late childhood.
II. Proximal femur physes 10 :
Proximal femoral epiphysis:
Thirteen percent to 15% of leg length.
Thirty percent length of the femur.
Grows 3 mm per year.
Contributes to femoral neck growth.
Injury can lead to coxa vara or valga.
Primary ossification centers (triradiate cartilage): endochondral ossification:
Ilium appears on radiographs at 3 weeks.
Ischium appears on radiographs at 16 weeks.
Pubis appears on radiographs at 20 weeks.
Fusion of centers at 12 years in females and at 14 years in males.
Secondary ossification centers of the acetabulum:
Os acetabuli (anterior wall).
Acetabular epiphysis (superior acetabulum).
Secondary ossification center of the ischium (posterior wall).
Appear at 8 years.
Fuse at 17 to 18 years.
Secondary ossification centers of the pelvis:
Iliac crest: appears at 13 years and fuses at 15 to 17 years.
Ischial apophysis: appears at 15 years and fuses at 19 to 25 years.
AIIS: appears at 14 years and fuses at 16 years.
Angle of pubis.
Lateral wing of the sacrum.
History and Examination
I. Information from emergency medical transport professionals:
Mechanism of injury.
Level of consciousness.
Initial physical examination.
II. Initial assessment:
Exposure and environment.
Inability to bear weight.
Hearing a “pop” during exercise.
IV. Physical examination:
Abnormal lower extremity positioning:
External rotation of one or both extremities.
Leg length shortening.
Degloving injury (Morel–Lavallée).
Evaluate for crepitus and tenderness.
Test pelvis stability with gentle lateral compressive or rotational force.
Point tenderness for avulsion injuries.
Lower extremity motor examination.
Lower extremity sensory examination.
Palpate and/or Doppler dorsalis pedis and posterior tibial arteries.
Table 12.2 Bucholz’s classification for pediatric acetabulum fractures
Salter Harris I or II
Salter Harris V
Table 12.4 Torode–Zieg classification for pediatric pelvic ring fractures
Fracture of the iliac wing
Fracture of the pelvic ring without segmental instability
Fracture of the pelvic ring with segmental instability
Scrotal/labial or perineal hematoma.
Blood at urethral meatus.
Traumatic laceration of perineum.
Vaginal/rectal examination for open fracture.
For low-energy mechanisms, suspicion of avulsion fracture.
Resisted activation of muscle group implicated.