12 Pediatric Hip Fractures



Joshua D. Harris, Robert A. Jack II

12 Pediatric Hip Fractures



Introduction



Proximal Femur Fractures




  • I. “Hip fractures” account for less than 1% of all pediatric fractures. 1 , 2



  • II. Mechanism of injury:




    1. High-energy trauma (75 −80%)



    2. Breech delivery.



  • III. High rate of complications due to age-dependent challenging blood supply.



Acetabular 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:




    1. Lateral compression injuries greater than anteroposterior (AP) injuries.



    2. Higher rate of single ring break than adults.



    3. Increased plasticity.



    4. More robust and absorbent cartilage.



    5. Sacroiliac (SI) joint and pubic symphysis are more elastic:




      1. Different injury patterns.



      2. Prior to triradiate closure: bone weaker than ligament, resulting in isolated pubic rami or iliac wing fracture, rather than pelvic ring disruption.



    6. Thickened periosteum stabilizes fractures.



    7. Lower rate of hemorrhage:




      1. Smaller blood vessels.



      2. Higher capacity for vasoconstriction.



      3. Lower likelihood of “open book” injuries.



Pelvic Avulsion Fractures 5 7




  • I. Result of low-energy trauma.



  • II. Tendon is disrupted from origin or insertion during explosive exercises:




    1. Eccentric contraction of muscle causing traction injury to cartilaginous apophysis.



    2. Sprinting.



    3. Jumping.



  • III. Multiple origins/insertions ( Fig. 12.1 ):




    1. Ischial tuberosity avulsion: hamstring (semimembranosus superolaterally and conjoint semitendinosus/biceps femoris inferomedially) or adductors.

      Fig. 12.1 (a, b) 1. The muscles of the thigh, hip, and gluteal region. (a) Shows anterior superficial and (b) shows anterior deep. The origins and insertions of the muscles are indicated by color shading (red = origin; blue = insertion). (Source: Schuenke M, Schulte E, Schumacher U. Thieme Atlas of Anatomy. General Anatomy and Musculoskeletal System. 2nd edition. ©2014, Thieme Publishers, New York. Illustrations by Voll M and Wesker K.)


    2. Anterior inferior iliac spine (AIIS) avulsion: direct head of the rectus femoris.



    3. Anterior superior iliac spine (ASIS) avulsion: sartorius, tensor fascia lata, and inguinal ligament.



    4. Lesser trochanter avulsion: iliopsoas.



    5. Pubic symphysis.



    6. Iliac crest avulsion: abdominal musculature; also crest apophysitis is a repetitive overuse traction injury; differentiate per Risser’s staging (U.S. system):




      1. Stage 0: no ossification of apophysis.



      2. Stage 1: most anterior one-fourth of apophysis ossified.



      3. Stage 2: most anterior half of apophysis ossified.



      4. Stage 3: most anterior three-fourths of apophysis ossified.



      5. Stage 4: apophysis ossified, but not yet fused to the iliac wing.



      6. Stage 5: completely ossified apophysis fuses to the iliac wing.



    7. Greater trochanter avulsion: hip abductors.



Anatomic Considerations




  • I. Unique blood supply of proximal femur ( Fig. 12.2 ) 8 , 9 :




    1. Infants:




      1. Metaphyseal vessels originating from the medial and lateral femoral circumflex arteries 10 :




        1. Transverse femoral physis and supply the proximal epiphysis.



      2. Artery of ligamentum teres.



    2. Age older than 2 years 10 :




      1. Cartilaginous physis of the proximal femur is barrier to the femoral head blood flow.

        Fig. 12.2 Anterior view of the right proximal femur demon strating the arterial blood supply.


      2. Main blood supply is via the lateral epiphyseal vessels from the medial femoral circumflex artery:




        1. Posterosuperior and posteroinferior epiphyseal vessels.



        2. Lie on the femoral neck.



        3. Vulnerable to injury with fracture.



    3. Age older than 4 years 11 , 12 :




      1. Artery of the ligamentum teres diminishes.



      2. Lateral femoral circumflex artery regresses by late childhood.



  • II. Proximal femur physes 10 :




    1. Proximal femoral epiphysis:




      1. Thirteen percent to 15% of leg length.



      2. Thirty percent length of the femur.



      3. Grows 3 mm per year.



    2. Trochanteric apophysis:




      1. Contributes to femoral neck growth.



      2. Injury can lead to coxa vara or valga.



  • III. Pelvis ossification 10 , 13 16 :




    1. Primary ossification centers (triradiate cartilage): endochondral ossification:




      1. Ilium appears on radiographs at 3 weeks.



      2. Ischium appears on radiographs at 16 weeks.



      3. Pubis appears on radiographs at 20 weeks.



      4. Fusion of centers at 12 years in females and at 14 years in males.



    2. Secondary ossification centers of the acetabulum:




      1. Os acetabuli (anterior wall).



      2. Acetabular epiphysis (superior acetabulum).



      3. Secondary ossification center of the ischium (posterior wall).



      4. Appear at 8 years.



      5. Fuse at 17 to 18 years.



    3. Secondary ossification centers of the pelvis:




      1. Iliac crest: appears at 13 years and fuses at 15 to 17 years.



      2. Ischial apophysis: appears at 15 years and fuses at 19 to 25 years.



      3. AIIS: appears at 14 years and fuses at 16 years.



      4. Pubic tubercle.



      5. Angle of pubis.



      6. Ischial spine.



      7. Lateral wing of the sacrum.



Classification




  • I. Delbet’s classification of pediatric proximal femur fractures 17 ( Table 12.1 ).



  • II. Bucholz’s classification of pediatric acetabulum fractures 18 ( Table 12.2 ).



  • III. Letournel’s classification of acetabulum fractures 19 23 ( Table 12.3 ).



  • IV. Torode–Zieg classification of pediatric pelvic ring injuries 24 ( Table 12.4 ).



History and Examination




  • I. Information from emergency medical transport professionals:




    1. Mechanism of injury.



    2. Level of consciousness.



    3. Initial physical examination.



  • II. Initial assessment:




    1. Airway.



    2. Breathing.



    3. Circulation.



    4. Disability/neuro status.



    5. Exposure and environment.



  • III. Symptoms:




    1. Pain.



    2. Inability to bear weight.



    3. Hearing a “pop” during exercise.



  • IV. Physical examination:




    1. Inspection:




      1. Abnormal lower extremity positioning:




        1. External rotation of one or both extremities.



        2. Leg length shortening.



      2. Skin:




        1. Degloving injury (Morel–Lavallée).



        2. Flank hematoma.



    2. Palpation:




      1. Evaluate for crepitus and tenderness.



      2. Test pelvis stability with gentle lateral compressive or rotational force.



      3. Point tenderness for avulsion injuries.



    3. Neurological examination:




      1. Lower extremity motor examination.



      2. Lower extremity sensory examination.



      3. Rectal examination.



    4. Vascular examination:




      1. Palpate and/or Doppler dorsalis pedis and posterior tibial arteries.
















































        Table 12.1 Delbet’s classification of pediatric proximal femur fractures

        Type


        Description


        Incidence (%)


        AVN rate (%)


        I


        Transphyseal separation


        8


        80


        IA


        Without dislocation of epiphysis from acetabulum

           

        IB


        With dislocation of epiphysis

           

        II


        Transcervical fracture


        40–50


        50


        III


        Cervicotrochanteric (basicervical) fracture


        30–35


        25


        IV


        Intertrochanteric fracture


        10–20


        <10


        Abbreviation: AVN, avascular necrosis.

















        Table 12.2 Bucholz’s classification for pediatric acetabulum fractures

        Type


        Fracture pattern


        Shearing


        Salter Harris I or II


        Crushing/impaction


        Salter Harris V





























































        Table 12.3 Letournel’s classification system for acetabulum fractures in skeletally mature patients

        Type


        Notes


        Frequency (%)


        Elementary

           

        Posterior wall


        Most common


        25


        Posterior column


        Detachment of ischioacetabular segment from innominate bone


        3–5


        Anterior wall


        Rare


        1–2


        Anterior column


        Anterior border of innominate bone displaced form intact ilium


        3–5


        Transverse


        Only elementary fracture to involve both columns


        5–19


        Associated

           

        Associated both columns


        Acetabulum is completely separate from axial skeleton. “Spur sign” on obturator oblique


        23


        Transverse and posterior wall


        Transverse component may be transtectal, juxtatectal, or infratectal


        20


        T-shaped


        T portion is an inferior vertical fracture


        7


        Anterior column/wall and posterior hemitransverse


        75% will involve anterior column and not wall


        7


        Posterior column and posterior wall


        Only associated fracture that does not involve both columns


        3–4























        Table 12.4 Torode–Zieg classification for pediatric pelvic ring fractures

        Type


        Description


        I


        Avulsion injury


        II


        Fracture of the iliac wing


        III


        Fracture of the pelvic ring without segmental instability


        IV


        Fracture of the pelvic ring with segmental instability



    5. Urogenital examination:




      1. Scrotal/labial or perineal hematoma.



      2. Blood at urethral meatus.



      3. Traumatic laceration of perineum.



      4. Hematuria.



      5. Vaginal/rectal examination for open fracture.



    6. Special tests:




      1. For low-energy mechanisms, suspicion of avulsion fracture.



      2. Resisted activation of muscle group implicated.

Only gold members can continue reading. Log In or Register to continue

Dec 29, 2020 | Posted by in ORTHOPEDIC | Comments Off on 12 Pediatric Hip Fractures
Premium Wordpress Themes by UFO Themes