Keywords:
Bones, Musculoskeletal joint, Musculoskeletal system, MR, Conventional radiography, Staging, Statistics, Diagnostic procedure, Developmental disease, Pathology, Inflammation
Authors:
A. Chellathurai; Chennai/IN
DOI:
10.26044/ecr2019/C-3003
Results
The findings obtained were grouped under three stages on the radiological progression of appearances.
STAGE I
- Variable Radiographic joint space narrowing,
- Wedge shaped focal area of T2 hyper/ T1 hypointensity ( Characterstic and Earliest finding in MRI) centered in the middle one third of the femoral head in coronal images
- ±Synovial hypertrophy and joint effusion.
STAGE II
- Superomedial Acetabular edema along the triradiate cartilage in the affected hip in addition to the Stage I findings.
- Protrusio acetabuli may be seen
- ± Synovial hypertrophy and joint effusion
STAGE III
- Widening of the T2 hyperintensity of the proximal femoral epiphysis,
- Collapse of the femoral head,
- Extensive acetabular involvement,
- Osteoporotic changes and
- Degenerative changes with loss of joint space (fibrous ankylosis).
- ± Overgrowth of femoral head on the neck called “buttress” sign, osteophyte formation
STATISTICAL ANALYSIS
- Gender wise grade analysis shows that there is no significant gender predilection (p> 0.05)
- All the 14 cases showed unilateral hip involvement
- The x ray findings of protrusio acetabuli and degenerative changes were useful for staging with p value of <0.05.
- MRI findings of geographic rectangular femoral head hyperintensity,
flattening of femoral head,
acetabular abnormal signal intensity can significantly (p-value < 0.05) differentiate various stages.
- Plain radiograph and MRI studies of fourteen patients were evaluated by two independent radiologists.
The overall interobserver concordance between radiologists for the staging of ICH as analysed by a statistician was very good (kappa value,
0.901).
TABLE 1:DISTRIBUTION OF FINDINGS IN VARIOUS STAGES AND THEIR STATISTICAL SIGNIFICANCE
No
|
Modality
|
Findings
|
Stage I
|
Stage II
|
Stage III
|
Fisher's Exact Test P-Value
|
1
|
Radiograph
|
Joint space narrowing
|
5/9
|
3/3
|
2/2
|
0.365
|
2
|
Protrusio acetabuli
|
0/9
|
2/3
|
0/2
|
0.043
|
3
|
Degenerative changes
|
0/9
|
0/3
|
2/2
|
0.011
|
4
|
MRI
|
Geographic Rectangular Femoral head hyperintensity without acetabular changes.
|
9/9
|
0/3
|
0/2
|
0.001
|
5
|
Hyperintensity in the aetabulam
|
0/9
|
3/3
|
2/2
|
0.001
|
6
|
hyperintensity in the aetabulam without flattening of femoral head /degenerative changes
|
0/9
|
3/3
|
0/2
|
0.004
|
7
|
Flattening of femoral head +
Fibrous ankylosis
|
0/9
|
0/3
|
2/2
|
0.011
|
8
|
Mild joint effusion
|
3/9
|
3/3
|
2/2
|
0.083
|
9
|
Synovial thickening
|
2/9
|
2/3
|
2/2
|
0.119
|
10
|
Fibrous ankylosis
|
0/9
|
0/3
|
1/2
|
0.143
|
DIFFERENTIAL DIAGNOSIS:
INFECTION : the hip joint space is usually increased.
Culture of joint fluid helps.
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.
The radiographic diagnosis of fractures,
neoplasms,
SCFE,
and Legg-Calve-Perthes disease should be readily apparent.
RADIOLOGIC DIAGNOSTIC CRITERIAE:
- 9-12 year old (girls) presenting with unilateral hip pain
- The radiograph showing concentric diminution of the joint space to < 3 mm with periarticular osteopenia and pelvic tilting without osteophyte formation is a diagnostic criterion of chondrolysis.
OR
- The geometric rectangular wedge shaped T2 hyper/ T1 hypointense lesion centered in the middle one third of the proximal femur in coronal images is the earliest and the diagnostic feature in MRI.
- HPE not required.
Table 2. Stage,
treatment and outcome in idiopathic chondrolysis of hip
Stage
|
Institution Treatment protocol
|
Outcome
|
Follow-up imaging
|
STAGE I
|
Control of synovial inflammation with non-steroidal anti-inflammatory drug/TNF inhibitor,
protect weight bearing and maintenance of range of motion
|
significant improvement
|
complete disappearance of femoral head oedema in MRI in few patients
|
STAGE II
|
Partial capsulectomy followed by traction and aggressive rehabilitation,
soft tissue release with anti-inflammatory agents.
|
Clinical satisfactory improvement.
Long-time outcome is poor.
|
No significant radiological improvement in early imaging,
|
STAGE III
|
Arthrodiastasis with external fixation
Total Hip Replacement
|
Poor
|
|