Apophysitis and Apophyseal Avulsion of the Pelvis

PHYSICIAN PERSPECTIVE
Verle Valentine, MD, Report Editor
Apophysitis and Apophyseal Avulsion
of the Pelvis
Rebecca L. Carl, MD • Children’s Memorial Hospital Chicago
T
he phrase “children are not little adults” is
a popular adage among health professionals
caring for children. This saying holds true for
overuse injuries in young athletes. Children
and adolescents, with their immature skeletons, have different injury patterns than
those exhibited by skeletally mature individuals. Strains of muscles that span the hip
and attach to the pelvis
are a common cause
Key Points
of hip pain in adult
athletes, and these
Young athletes have distinctive patterns
injuries can occur in
of injury.
younger patients as
well. In young athletes,
Irritation and injury to the pelvic growth
irritation of the accesareas can cause hip pain.
sory growth areas of
Apophyseal injuries in young athletes are
the pelvis (i.e., pelvic
often mistakenly diagnosed as muscle
apophysitis) and avulinjuries.
sion fractures of the
pelvic apophyses are
often mistakenly diagnosed as muscle strains
or hip pointers. Most clinicians are familiar
with Osgood-Schlatter disease, which is an
irritation of the apophysis of the tibial tuberosity. Conditions affecting the apophyses of
the pelvis are less well known. Clinicians who
care for pediatric, adolescent, and young
adult athletes should be familiar with the
pathophysiology of apophysitis and apophyseal avulsion injuries.
Skeletal Development
and Pathophysiology
The skeleton forms in the first weeks of
fetal development and is initially composed
entirely of cartilage. During subsequent fetal
development, and continuing after birth and
into childhood and adolescence, the soft cartilage skeleton is transformed into a skeleton
made of mineralized bone. This transformation process is known as endochondral ossification. The physis, or growth plate, is the
site where endochondral ossification occurs.
The cartilage cells of the physis produce an
extracellular matrix that ossifies, thereby
forming hard bone tissue. This process results
in longitudinal bone growth that increases
its length. Long bones have a physis at one
or both ends. Many bones of the immature
skeleton have apophyses, which are growth
areas that have muscle attachments in close
proximity. Bone growth at the apophyses fills
out surface contours, but does not contribute
to linear growth. Having open growth plates
has many advantages, e.g., fracture healing
and remodeling are accelerated in young
patients; however, because apophyses and
physes are composed of cartilage, they are
susceptible to injury. Whereas adults are
more likely to experience disruption of ligaments, muscles, and tendons with overuse,
© 2012 Human Kinetics - IJATT 17(2), pp. 5-9
international journal of Athletic Therapy & training
march 2012  5
children are more likely to have injuries to the physes
and apophyses. Apophysitis refers to irritation of the
apophysis, due to repetitive microtrauma that can
occur during participation in athletics. With repeated
muscle contractions, the apophysis can become irritated and may widen. Apophyseal avulsion fractures
generally result from sudden traction generated by a
strong eccentric contraction of a muscle group attached
adjacent to the affected apophysis.
Case #1
A 15-year-old male track athlete presents to the training
room with acute onset of right hip pain. He had sudden
onset of his pain while sprinting during practice. He
recalls feeling a “pop” at the time of injury. He is able
to bear weight. On physical exam, he is tender over the
anterior superior iliac spine (ASIS). Hip range-of-motion
is symmetric, except for slightly decreased extension
on the right. He reports pain with passive hip extension
and resisted hip flexion. The athletic trainer refers him
for radiographs; these demonstrate the presence of an
avulsion fracture of the ASIS (Figure 1).
iliac crest. Hip range of motion is full and symmetric.
Subsequent radiographs demonstrate widening of the
iliac crest apophysis on the left.
Anatomy
The apophyses of the hip and pelvis are located at the
anterior superior iliac spine (ASIS), anterior inferior
iliac spine (AIIS), ischial tuberosity (IT), pubic symphysis, iliac crest, and greater and lesser trochanters.
Knowledge of the bone structure of the hip and pelvis,
and muscle origins and insertions, is critical for understanding apophysitis. For example, the iliopsoas is the
most powerful of the hip flexors, which inserts on the
lesser trochanter. With acute, forceful hip flexion, as
the patient in case #1 experienced, the contraction of
the iliopsoas can cause avulsion of the lesser trochanter
of the apophysis.
The internal and external abdominal oblique muscles insert onto the iliac crest. Repeated trunk rotation
puts traction on the iliac crest, which can cause iliac
apophysitis, as seen in case #2. Table 1 lists the sites
of pelvic apophyses and associated muscles that attach
in close proximity.
Epidemiology
Figure 1 Avulsion of the anterior superior iliac spine (large white
arrow). Other sites where apophysitis can occur are indicated with
arrows as follows: Iliac crest (gray arrow), ischium (small white arrow),
and anterior inferior iliac spine (black arrow).
Case #2
A 16-year-old female soccer player presents to the
training room with a two-week history of left hip pain.
She reports that her pain had an insidious onset; she
believes it started while doing soccer kicking drills. She
indicates the lateral aspect of the hip as the location
of her pain. On physical exam, she is tender along the
6  march 2012
The exact incidence of pelvic apophysitis is unknown.
There are data available for other sites of apophysitis. For example, Kujala et al. surveyed nearly 200
individuals who had been active in athletics during
childhood and adolescence and found that 21% had
experienced symptoms of Osgood-Schlatter Disease
(OSD).1 Prevalence of OSD was elevated among siblings
of athletes with OSD and individuals with a history of
Sever Disease (apophysitis of the calcaneus). These
data suggest that individuals with apophysitis at one
site are more vulnerable to apophysitis at other sites.
Poor flexibility is a risk factor, particularly in a muscle
attached near the affected apophysis. The individuals with Sever Disease were more likely to have poor
flexibility, which may be associated with increased
susceptibility to apophysitis at other sites.
Athletes are vulnerable to apophyseal injuries
during the time that these growth areas are active.
The apophyses of the hip and pelvis generally appear
between 13 and 15 years of age, and they close in the
early to mid-twenties. The lesser trochanter apophysis
international journal of Athletic Therapy & training
Table 1. Apophyses of the Pelvis and Their Muscle Attachments
Bone Landmark
Muscle
Muscle Function
Anterior superior iliac spine
Sartorius (O)
Hip, knee flexion, external hip location
Anterior inferior iliac spine
Rectus Femoris (O)
Hip flexion, knee extension
Ischial Tuberosity
Hamstrings (O)
Hip extension, knee flexion
Iliac Crest
Abdominal Muscles (I)
Trunk rotation
Greater Trochanter
Gluteus medius, Gluteus minimus (I)
Hip abduction
Lesser Trochanter
Iliopsoas (I)
Hip flexion
Pubic ramus
Adductor longus, brevis, magnus,
pectineus, and gracilis (O)
Hip adduction
O-originates, I-inserts
is active earlier, usually appearing between 9 and 13
years of age and closing by 17.2
Rossi and Dragoni3 reviewed the records of over
1200 athletes between the ages of 11 and 35 who
had radiographs performed for assessment of hip
pain. They found pelvic apophysis avulsion fractures
in 16% of these athletes. The average age of the
patients with avulsion fractures was 13 (range of 11
to 17), and 68.5% of affected patients were male.
Additionally, there were 25 adult patients (ranging in
age from 22 to 35) with radiographic evidence of “old”
avulsion injuries. Athletes who participated in soccer
and gymnastics were most likely to be affected. The
ischial tuberosity was the most commonly affected site,
followed by the ASIS and the AIIS.3 In another study
of 27 patients with apophyseal avulsion fractures, the
ASIS was the most commonly affected site.4
Clinical History and Physical Examination
Apophysitis
Apophysitis results from repetitive muscle tension at
its attachment site. Patients tend to report an insidious
onset of pain. On physical exam, tenderness is elicited
by palpation over the apophysis. Pain is often elicited
by passive stretch and resisted manual muscle testing,
which puts traction on the irritated apophysis. Range of
motion is generally unaffected, or minimally reduced.
Apophyseal Avulsion
Patients with apophyseal avulsion commonly describe
acute onset of pain during an activity that involved
forceful muscle contraction. Many recall having felt a
“pop” at the time of injury. Athletes may demonstrate
international journal of Athletic Therapy & training
an antalgic gait or difficulty ambulating following an
avulsion injury. On physical exam, crepitus, swelling,
and/or bruising may be apparent. Most patients exhibit
significant tenderness in response to palpation of the
affected apophysis. They often experience pain during
passive stretching and difficulty in actively contracting the muscles attached near the affected apophysis.
Range of motion is often limited by pain during the
acute postinjury period.
Diagnostic Imaging
Apophysitis
Clinical history and examination provide the primary
findings for the diagnosis of apophysitis. In some
patients, radiographs demonstrate widening of the
apophysis. When radiographs are obtained, they should
include the contralateral pelvis and hip for comparison.
Magnetic resonance imaging (MRI) is rarely warranted
for patients with a clinical history that is strongly suggestive of apophysitis. When performed, MRI may
show edema surrounding the affected growth area.5
Apophyseal Avulsion
Following an acute injury, radiographs will clearly
demonstrate an avulsion fracture.6 With chronic injury,
the affected areas may look bulkier than normal, due
to new bone formation. The periosteal reaction and
new bone formation associated with healing of such
an injury may create an appearance that can be confused with a malignant neoplasm (Figure 2). Computed
tomography (CT) may be a helpful to ensure the correct
diagnosis in such cases.7-9
march 2012  7
conditions (e.g., radiculopathy) may cause pain that
is referred to the hip and pelvis.
Treatment
Apophysitis
Figure 2 The right ischium has a hazy, bubbly appearance consistent
with periosteal reaction secondary to apophyseal injury (white arrow).
The appearance of this lesion can be confused with that of a malignant
neoplasm.
Treatment includes cryotherapy and rest from activity.
Athletes can begin gentle stretching when daily activities become pain free, with subsequent progression to
strengthening exercises. Activity progression should
be gradual, with explosive, plyometric movements
involving muscles attached to a site near the affected
apophysis added last. Livel et al10 recently reported the
use of bone stimulator treatment to accelerate healing
in two patients with iliac crest apophysitis.
Apophysis Avulsion
Differential Diagnosis
For symptoms of apophysis over the anterior pelvis,
hip, and proximal thigh, including the ASIS, AIIS, pubic
ramus, and lesser trochanter, the differential diagnosis
includes adductor muscle strain, tendinopathy, snapping hip syndrome, labral tear, and femoroacetabular
impingement. Stress fracture, or stress reaction, of
the pubic ramus, acetabulum, or femoral neck can
also cause pain in this region. Slipped Capital Femoral
Epiphysis (SCFE) can be responsible for groin pain in
preadolescent and adolescent patients, which must be
ruled out in such patients.
Ischial tuberosity apophysitis or apophseal avulsion
may present similar symptoms to those associated
with hamstring strain, tendinopathy, or myofascial
pain. Referred pain from the lumbar spine can mimic
symptoms of apophysitis affecting the ischial tuberosity, lesser trochanter, or greater trochanter. Symptoms
associated with iliac crest apophysitis can be confused
with those of a strain of an abdominal muscle or irritation of the proximal portion of the iliotibial band. The
differential diagnosis for greater trochanter avulsion or
apophysitis includes greater trochanteric bursitis and
lateral snapping hip syndrome.
For any patient who presents with symptoms associated with pelvic apophyseal irritation or avulsion,
clinicians must consider the existence of systemic
conditions, such as inflammatory arthritis, malignancy,
or infection as potential causes of pain. Intraabdominal
abnormalities (e.g., appendicitis) and lumbar spine
8  march 2012
Avulsion of a pelvic apophysis generally heals with conservative therapy, including activity restriction and protected weight bearing when the patient has difficulty
with ambulation. If pain free after two to four weeks
of rest, the patient can progress to gentle stretching
and light resistance exercises. Athletes are generally
able to return to light sport-specific drills at six weeks
after injury and capable of return to full participation
at two months after injury if asymptomatic. Clinicians
should consider referral for surgical fixation of the
avulsed fragment if separated from its normal position
by more than 2.5 cm. Most apophysis avulsion injuries
heal with conservative treatment, but surgery may be
indicated for nonunion or excessive bone formation at
the injury site.11 Rossi and Dragoni3 reported that only
three out of 198 patients required surgery.
Conclusions
Sports medicine clinicians should suspect pelvic
apophysitis and apophyseal avulsion fracture in an
adolescent or young adult athlete who presents gluteal
or hip pain. Individuals with skeletal maturity tend to
experience injury to the musculotendinous junction,
because it is the weakest portion of the muscle-tendonbone unit. Individuals with incomplete skeletal growth
are more likely to experience injury to the cartilaginous
apophysis. Generally, this type of injury heals with conservative therapy, and athletes are eventually capable
of returning to the preinjury level of performance. 
international journal of Athletic Therapy & training
References
1.Kujala UM, Kvist M, Heinonen O. Osgood-Schlatter’s disease in adolescent athletes. Retrospective study of incidence and duration. Am J
Sports Med. Jul-Aug 1985;13(4):236-241.
2.Moeller JL. Pelvic and hip apophyseal avulsion injuries in young athletes. Curr Sports Med Rep. Apr 2003;2(2):110-115.
3. Rossi F, Dragoni S. Acute avulsion fractures of the pelvis in adolescent
competitive athletes: prevalence, location and sports distribution of
203 cases collected. Skeletal Radiol. Mar 2001;30(3):127-131.
4. Metzmaker JN, Pappas AM. Avulsion fractures of the pelvis. Am J Sports
Med. Sep-Oct 1985;13(5):349-358.
5. Sanders TG, Zlatkin MB. Avulsion injuries of the pelvis. Semin Musculoskelet Radiol. Mar 2008;12(1):42-53.
6. Fernbach SK, Wilkinson RH. Avulsion injuries of the pelvis and proximal femur. AJR Am J Roentgenol. Sept 1981;137(3):581-584.
7. Bahk WJ, Brien EW, Luck JV, Jr., Mirra JM. Avulsion of the ischial tuberosity simulating neoplasm: a report of 2 cases. Acta Orthop Scand. Apr
2000;71(2):211-214.
8. Stevens MA, El-Khoury GY, Kathol MH, Brandser EA, Chow S. Imaging
features of avulsion injuries. Radiographics. May-Jun 1999;19(3):655672.
9.Yamamoto T, Akisue T, Nakatani T, et al. Apophysitis of the ischial
tuberosity mimicking a neoplasm on magnetic resonance imaging.
Skeletal Radiol. Dec 2004;33(12):737-740.
10.Kivel CG, d’Hemecourt CA, Micheli LJ. Treatment of iliac crest apophysitis in the young athlete with bone stimulation: report of 2 cases. Clin
J Sport Med. Mar 2011;21(2):144-147.
11. McKinney BI, Nelson C, Carrion W. Apophyseal avulsion fractures of
the hip and pelvis. Orthopedics. Jan 2009;32(1):42.
Rebecca Carl is an attending physician in Pediatric Sports Medicine
at Children’s Memorial Hospital in Chicago. She is also an assistant
professor of Pediatrics at Northwestern University Feinberg School
of Medicine.
Don’t miss a single issue!
Frequency: Bimonthly
(January, March, May, July,
September, November)
ISSN (print): 2157-7277
ISSN (online): 2157-7285
International Journal of Athletic Therapy & Training
(IJATT) is dedicated to the unique needs of athletic
trainers and therapists. IJATT provides insights into
professional practice issues, highlights sports health
care techniques, shares experiential knowledge, and
presents practical applications of current research. IJATT
strives to present these subjects in a simple, streamlined
format that focuses on clinical applications and athlete
and patient care practices.
IJATT is also available in an online format that offers the
same great content available in the print edition with all
the convenience of electronically formatted material.
______ I already subscribe to IJATT. Please renew my subscription.
______ Yes! Please start my one year subscription to IJATT.
Print and online version ISBN: 978-0-7360-5309-9
Individual
Institution
US
❑ $57.00
❑ $342.00
International
❑ $72.00
❑ $357.00
Canada
❑ $69.00 CDN
❑ $417.00 CDN
UK
❑ £54.00 UK
❑ £270.00 UK
Europe
❑ €64.00 EURO
❑ €319.00 EURO
Australia
❑ $75.00 AUS
❑ $414.00 AUS
New Zealand
❑ $102.00 NZ
❑ $562.00 NZ
Subscription Total
Student
❑ $42.00
❑ $57.00
❑ $51.00 CDN
❑ £43.00 UK
❑ €51.00 EURO
❑ $55.00 AUS
❑ $75.00 NZ
$
Please visit the website for additional pricing and information.
Name ________________________________________________________________________
Institution _____________________________________________________________________
Advisor’s Name_________________________________Year In School ____________________
(students only)
(students only)
Address ______________________________________________________________________
City ______________________________________State______________ Zip _____________
Phone __________________________ E-mail (for journal online access)
____________________________________
Personal Orders (Prepayment in U.S. funds is required)
 My check or money order is enclosed. (A fee of $25.00 will be charged for checks returned for insufficient funds)
Charge my
❑Visa ❑ American Express ❑ Mastercard Exp. Date _______________
Cardholder Name _______________________________________________________________
Account No. ___________________________________________________________________
Human Kinetics
www.ATT-Journal.com
Access your journal through
the HK Journals app!
Available from the Apple App Store.
Signature _____________________________________________________________________
(Required for credit card orders)
Prices subject to change.
12/11
(800) 747-4457 US • (217) 351-5076 INT • (800) 465-7301 CDN • 44 (0) 113 255-5665 UK
(08) 8372-0999 AUS • 0800 222 062 NZ • Human Kinetics • P.O. Box 5076 • Champaign, IL 61825-5076
international journal of Athletic Therapy & training
march 2012  9