Adolescent Female with Hip Pain
Radiology Cases in Pediatric Emergency Medicine
Volume 4, Case 19
Collin S. Goto, MD
Children's Medical Center of Dallas
University of Texas Southwestern School of Medicine
     This patient is a previously healthy 11 year old 
female who presents to the emergency department with 
a 2 week history of gradually worsening bilateral hip 
pain, left greater than right.  She denies involvement of 
any other joints.  There is no history of trauma, fever, 
weight loss, recent illness, and the patient denies 
sexual activity.  The family history is negative for 
rheumatologic disease.
     Exam:  VS T 36.7 (Tympanic), P 72, RR 18, BP 
110/68.  She is of average body build, with a weight of 
38 kg.  She is alert and not ill-appearing.  Head, neck, 
lung, heart, abdominal, and neurologic exams are all 
within normal limits.  On examination of the lower 
extremities, she has pain with both active and passive 
range of motion in both hips, left greater than right.  
Pain is elicited with all movements, including flexion, 
extension, adduction, abduction, and internal/external 
rotation.  Nearly full passive range of motion can be 
attained, but with difficulty and pain.  There is no 
erythema, swelling, or increased warmth.  There is no 
muscle atrophy distally.  She walks with a slow, stiff, 
antalgic gait (see Case 16 in Volume 4, A Limping 
6-Year Old).  The remaining joints of the upper and 
lower extremities are not involved.
     Laboratory Results:  CBC WBC 8,800, 44% 
neutrophils, 41% lymphocytes, 5% monocytes, 8% 
eosinophils, and 2% basophils.  The hemoglobin, 
hematocrit, and platelet count are normal.  The 
erythrocyte sedimentation rate is 9 mm/hr, and the 
C-reactive protein is < 1mg/dL.  Hip radiographs are 

View hip radiographs.

     Do you see anything abnormal about these 
radiographs.  Clinically, we would expect to find 
potential abnormalities in both hips, with the left worse 
than the right.  Thus comparing one side to the other 
may not be as helpful as in a unilateral problem.
     AP and frogleg views of the hips demonstrate 
bilateral joint space narrowing, left greater than right.  In 
addition, there are early subchondral cysts seen on the 
left within the femoral head.  There is no evidence of 
fracture, dislocation, or slipped capital femoral 
epiphysis.  This condition is known as idiopathic 
chondrolysis of the hips.

Teaching points and Discussion:
     1.  Idiopathic chondrolysis of the hip was first 
described by Jones in 1971 as a condition 
characterized by an extensive loss of articular cartilage 
of the femoral head and acetabulum, in the absence of 
known etiologies of chondrolysis, such as slipped 
capital femoral epiphysis (SCFE), prolonged 
immobilization, infection, rheumatoid arthritits, and 
     2.  The typical presentation of idiopathic 
chondrolysis of the hip is that of an afebrile, previously 
healthy, adolescent female with an insidious onset of 
hip, thigh, or knee pain, associated with a limp and 
progressive loss of movement of the affected hip.  
Patients often have restricted hip movements at the 
time of presentation, with fixed flexion, abduction, or 
adduction deformities.  Hip radiographs show a 
characteristically narrowed joint space.  The disease 
process may involve one or both hips.  Infectious 
workup, including white blood cell counts, blood 
cultures, and ESR are normal.  Rheumatologic workup 
similarly is negative.
     3.  The differential diagnosis for hip pain in 
adolescents includes septic arthritis, toxic synovitis, 
trauma, SCFE, Legg-Calve-Perthes disease (juvenile 
idiopathic avascular necrosis of the femoral head), 
monoarticular rheumatoid arthritis, tuberculosis, 
leukemia, synovioma, and other neoplasms.  Narrowing 
of the hip joint space is an important finding that 
virtually excludes acute synovitis, bacterial and viral 
arthritis, trauma, or the early stages of juvenile 
rheumatoid arthritis (JRA) or spondyloarthritis.  In the 
early stages of these disorders, the hip joint space is 
normal or widened.  In addition, monoarticular JRA is 
predominantly a disease of the knee, ankle, or wrist.  
The hip joint is very rarely affected, especially in girls.  
The radiographic diagnosis of fractures, neoplasms, 
SCFE, and Legg-Calve-Perthes disease should be 
readily apparent.
     4.  Early radiographic findings of idiopathic 
chondrolysis of the hip include symmetrical joint space 
narrowing (due to loss of articular cartilage), 
periarticular osteoporosis, erosions of the articular 
cartilage of the acetabulum and femoral head, blurring 
of the subchondral line, subchondral cyst formation, and 
protrusio acetabuli (as noted by a progressive increase 
in the center edge of Wiberg).  Late changes include 
marginal osteophyte formation, lateral buttress 
formation, early closure of capital and trochanteric 
epiphyseal plates, widening of the femoral head and 
neck, and ankylosis.
     5.  The method of measurement of the width of the 
femoral head and neck is described in Bleck (1983).

View diagram of this method.

     The center of the head (O) is located by the method 
of Wiberg.  The femoral neck is bisected through the 
center (line ab).  Line cd runs perpendicular to line ab 
through the center of the head.  The length of line cd to 
the margins of the head is the width.  Line ef is drawn 
perpendicular to line ab at the junction of the head and 
neck to measure the width of the femoral neck.
     6.  The method of measurement of the width of the 
hip joint space on an anteroposterior radiograph of the 
hips is also described in Bleck (1983).

View diagram of this method.

     The center of the femoral head is located and the 
line for measurement of the width of the femoral head is 
marked.  The femoral head is bisected by a line 
perpendicular to the line for measurement of the width.  
Each half segment (90 degrees) is divided into four 
quarters of 22.5 degrees.  The width of the joint within 
the first lateral quadrant of the bisected head is 
     By this method, our patient's hip joint width 
measured 1 mm on the left and 2-3 mm on the right.  
Normal hip joint width is reported to be 3-5 mm.
     7.  Histologic features of idiopathic chondrolysis of 
the hip include thickening of the capsule with 
edematous changes in the capsule and synovium.  
There are articular surface changes with fibrillation, 
fragmentation, and progressive loss of cartilage.  An 
infiltration of lymphocytes is seen within the synovium, 
and there may be degeneration of chondrocyte nuclei 
and loss of cells in the lacunae.
     8.  Early reports suggested that therapy should 
consist of physical therapy, non-weightbearing, and 
non-steroidal anti-inflammatory drugs.  Soft tissue 
releases and traction were occasionally used to treat 
contractures.  However, many cases resulted in a poor 
outcome with fibrous ankylosis and loss of movement in 
the hip.  More recently, it has been suggested that 
non-weightbearing does not adequately unload the hip, 
and the positioning of the hip when crutches are used 
may actually potentiate the flexion contracture.  Casting 
or any other immobilization is contraindicated as the 
pathologic process involving the articular cartilage may 
be compounded.  Roy and Crawford reported a small 
series of patients treated with subtotal circumferential 
capsulectomy and muscle release, followed by an 
aggressive rehabilitation program consisting of split 
Russell's traction, continuous passive motion, and 
limited weightbearing.  This was supplemented by 
active and passive range of motion exercises, resulting 
in a resolution of symptoms, improvement in range of 
motion and widening of the joint space, rather than the 
usual progressive course.
     9.  Our patient's presentation was typical of 
idiopathic chondrolysis of the hip.  The history, physical 
examination, laboratory data, and radiographs all 
supported this diagnosis.  The diagnosis is suggested 
when an adolescent patient presents with insidious 
onset of hip pain, radiographs show a narrowed hip joint 
space, and known causes of chondrolysis, such as 
SCFE, prolonged immobilization, or trauma are absent.  
Infection is unlikely if the patient is afebrile, with a 
normal white blood cell count, ESR, and CRP.  In 
addition, the hip joint space is usually increased with 
infection, rather than decreased.  Monoarticular JRA 
rarely affects the hip, and in the early stages, typically 
demonstrates a widened joint space with an effusion, 
and an increased ESR and CRP.  Thus, the 
radiographic finding of a narrowed hip joint space in 
patients presenting with hip pain is clearly an important 
distinction which limits the differential diagnosis 
significantly.  Awareness of the clinical entity of 
idiopathic chondrolysis of the hip is important because 
of the loss of function and severe disability often 
associated with it.  

     1.  Bleck EE:  Idiopathic chondrolysis of the hip.  J 
Bone Joint Surg 1983;65(9):1266-1275.
     2.  Daluga DJ, Millar EA:  Idiopathic chondrolysis of 
the hip.  J Pediatr Ortho 1989;9(4):405-411.
     3.  Duncan JW, Nasca R, Schrantz J:  Idiopathic 
chondrolysis of the hip.  J Bone Joint Surg 
     4.  Hughes AW:  Idiopathic chondrolysis of the hip:  
A case report and review of the literature.  Ann Rheum 
Dis 1985;44:268-272.
     5.  Jones BS:  Adolescent chondrolysis of the hip 
joint.  SA Med J 1971;45:196-202.
     6.  Kozlowski K, Scougall J:  Idiopathic chondrolysis 
- diagnostic difficulties.  Pediatr Radiol 
     7.  Moule NJ, Golding JSR:  Idiopathic chondrolysis 
of the hip.  Clin Radiol 1974;25:247-251.
     8.  Roy DR, Crawford AH:  Idiopathic chondrolysis of 
the hip:  Management by subtotal capsulectomy and 
aggressive rehabilitation. J Pediatr Ortho 
     9.  Sartoris DJ, Resnick D:  Radiologic vignette;  
primary disorders of articular cartilage in childhood.  J 
Rheum 1988;15(5):812-819.
     10.  Sivanantham M, Kutty MK:  Idiopathic 
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the literature.  Aust NZ J Surg 1977;47(2):229-231.
     11.  Smith EJ, Ninin DT, Keays AS:  Idiopathic 
chondrolysis of the hip:  A case report.  SA Med J 
     12.  Sparks LT, Dall G:  Idiopathic chondrolysis of 
the hip joint in adolescents:  Case reports.  SA Med 
J 1982;63(23):883-886.
     13.  van der Hoeven H, Keessen W, Kuis W:  
Idiopathic chondrolysis of the hip:  A distinct clinical 
entity?  Acta Orthop Scand 1989;60(6):661-663.
     14.  Wenger DR, Mickelson MR, Ponseti IV:  
Idiopathic chondrolysis of the hip:  Report of two cases.  
J Bone Joint Surg 1975;57(2):268-271.

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Loren Yamamoto, MD, MPH
Associate Professor of Pediatrics
University of Hawaii John A. Burns School of Medicine