Diagnosis of Hip Complaints: Arthritis & Neoplasms Part I | El Paso, TX.
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Table of Contents
Degenerative Joint Disease (DJD)
Macroscopic & Microscopic Appearance of Normal vs. Damaged Articular Hyaline Cartilage by DJD
Hip Osteoarthritis (OA) aka Osteoarthrosis
Symptomatic and potentially disabling DJD
Progressive damage and loss of the articular cartilage causing denudation and eburnation of articular bone
Cystic changes, osteophytes and gradual joint destruction
Develops d/t repeated joint loading and microtrama
Obesity, metabolic/genetic factors
Secondary Causes: trauma, FAI syndrome, osteonecrosis, pyrophosphate crystal depostion, previous inflammatory arthritis, Slipped Capital Femoral Epiphysis, Leg-Calves-Perthes disease in children etc.
Hip OA, 2nd m/c after knee OA. Women>men
88-100 symptomatic cases per 100000
Radiography is the Modality of Choice for the Dx and Grading of DJD
Special imaging is not required unless other complicating factors exist
Acetabular-femoral joint is divided into superior, axial and medial compartments/spaces
Normal joint space at the superior compartment should be 3-4-mm on the AP hip/pelvis view
Understanding the pattern of hip joint narrowing/migration helps with the DDx of DJD vs. Inflammatory arthritis
In DJD, m/c hip narrowing is superior-lateral (non-uniform) vs. inflammatory axial (uniform)
AP Hip Radiograph Demonstrates DJD
With non-uniform loss of joint space (superior migration), large subcortical cysts and subchondral sclerosis
Radiographic features:
Like with any DJD changes: radiography will reveal L.O.S.S.
L: loss of joint space (non-uniform or asymmetrical)
O: osteophytes aka bony proliferation/spurs
S: Subchondral sclerosis/thickening
S: Subcortical aka subchondral cysts “geodes”
Hip migration is m/c superior resulting in a “tilt deformity”
Radiographic Presentation of Hip OA May Vary Depending On Severity
Mild OA: mild reduction of joint space often w/o marked osteophytes and cystic changes
During further changes, collar osteophytes may affect femoral head-neck junction with more significant jint space loss and subchondral bone sclerosis (eburnation)
Cyst formation will often occur along the acetabular and femoral head subarticular/subchondral bone “geodes” and usually filled with joint fluid and some intra-articular gas
Subchondral cysts may be occasionally very large and DDx from neoplasms or infection or other pahtology
Coronal Reconstructed CT Slices in Bone Window
Note moderate joint narrowing that appears non-uniform
Sub-chondral cysts formation (geodes) are noted along the acetabular and femoral head subchondral bone
Other features include collar osteophytes along head-neck junction
Dx: DJD of moderate intensity
Referral to the Orthopedic surgeon will be helpful for this patient
AP Pelvis (below first image), AP Hip Spot (below second image) CT Coronal Slice
Note multiple subchondral cysts, sever non-uniform joint narrowing (superior-lateral) and subchondral sclerosis with osteophytes
Advanced hip arthrosis
Severe DJD, Left Hip
When reading radiological reports pay particular attention to grading of hip OA
Most severe (advanced) OA cases require total hip arthroplasty (THA)
Refer your patients to the Orthopedic surgeon for a consultation
Most mild cases are good candidate for conservative care
Hip Arthroplasty aka Hip Replacement
Can be total or hemiarthroplasty
THA can be metal on metal, metal on polythelen and ceramic on ceramic
Hybrid acetabular component with polyethelen and metal backing is also used (above right image)
THA can be cemented (above right image) and non-cemented (above left image)
Non-cemented arthroplasty is used on younger patients utilizing porous metallic parts allowing good fusion and bone ingrowth into the prosthesis
Failed THA May Develop
Most develop within first year and require revision
Femoral stem may fracture (above left)
Postsurgical infection (above right)
Fracture adjacent to prosthesis (stress riser)
Particle disease
Femoroacetabular Impingement Syndrome
(FAI): abnormality of normal morphology of the hip leading to eventual cartilage damage and premature DJD
Clinically:hip/groin pain aggravated by sitting (e.g. hip flexed & externally rotated). Activity related pain on axial loading esp. with hip flexion (e.g. walking uphill)
Pincer type acetabulum: > in middle age women potentially many causes
CAM-type deformity: > in men in 20-50 m/c 30s
Mixed type (pincer-CAM) is most frequent
Up until the 90s FAI was not well-recongnised
FAI Syndrome
CAM-type FAI syndrome
Radiography can be a reliable Dx tool
X-radiography findings: osseous bump on the lateral aspect of femoral head-neck junction. Pistol-grip deformity. Loss of normal head sphericity. Associated features: os acetabule, synovial herniation pit (Pit’s pit). Evidence of DJD in advanced cases
MRI and MR arthrography (most accurate Dx of labral tear) can aid the diagnosis of labral tear and other changes of FAI
Referral to the Orthopedic surgeon is necessary to prevent DJD progression and repair labral abnormalities. Late Dx may lead to irreversible changes of DJD
AP Pelvis: B/L CAM-type FAI syndrome
Pincer-Type FAI with Acetabula Over-Coverage
Key radiographic signs: “Cross-over sign” and abnormal center-edge and Alfa-angle evaluation methods
Dx of FAI
Center-edge angle (above the first image) and Alfa-angle (above the second image)
B/L CAM-type FAI with os acetabule (above right image)
MR Arthrography
Labral tear and CAM-type FAI syndrome on axial (above left) and coronal T2 W (above right) MR arthrography
Note acetabula labral tear. Referral to orthopedic surgeon is required. For more information: