2. INTRODUCTION:
• Synovial chondromatosis is a rare condition in which foci of cartilage
develop in the synovial membrane as a result of benign metaplasia of
the subsynovial connective tissue.
• Countless tiny fronds of synovial membrane undergo cartilage
metaplasia at their tips; these tips break free and may ossify.
• Self-limited and non-aggressive.
• Also known as primary synovial osteochondromatosis, synovial
chondrometaplasia and Reichel syndrome.
3. INCIDENCE AND DEMOGRAPHICS:
• Exact prevalence is unknown.
• Male-to-female ratio of 2:1.
• Patients are usually aged 20-40 years.
4. ETIOLOGY
• Primary synovial chondromatosis
• Etiology unknown.
• Secondary synovial chondromatosis
• more common.
• Free chondral or osteochondral fragments formed by underlying disease
implant into the synovium and induce metaplastic cartilage around them.
• Occurs in preexistent osteoarthritis, , rheumatoid arthritis,
osteonecrosis, infection or trauma.
5. PATHOPHYSIOLOGY
• Benign process associated with an extremely low risk of malignancy.
• Typically monoarticular, with the large joints such as the knee joint is
involved in 60-70% of cases; the shoulder, elbow, and hip are the next
most frequently involved joints
• Growth factors BMP-2 and BMP-4 may promote cartilaginous and
osteogenic metaplasia.
6. PRESENTATION:
• Gradual onset of monoarticular pain and stiffness, decreased range of
motion, effusions, crepitation and eventual locking of the joint.
• Secondary synovial chondromatosis may be present after long
standing osteoarthritis, trauma or infection.
7. EXAMINATION
• LOOK the joint may be enlarged with no overlying skin changes.
• FEEL large effusion with spongy sensation, palpable loose bodies in
synovial recesses, tenderness along joint line.
• MOVE ROM is typically decreased and movement is painful.
Ligamentous examination (eg, Lachman test, drawer test) are normal.
8. INVESTIGATIONS
• CBC, ESR and C-reactive protein level if the physical findings suggest
possible infection.
• Results are expected to be normal in primary synovial chondromatosis,
but may be elevated in secondary synovial chondromatosis due to
systemic inflammation.
9. X-RAY APPEARANCE
• Frequently normal. Between 5-30% of
patients do not have radiographically
visible calcifications although secondary
widening of the joint space may be noted.
• If loose bodies undergo ossification, they
may be visible in the joint space. The
pattern of mineralization varies with size.
• In secondary synovial chondromatosis,
changes consistent with the underlying
disease process are evident.
Radiograph of the knee with synovial
chondromatosis. No abnormality noted.
Radiograph of the knee with synovial
chondromatosis. Visible calcification in
joint space
10. MAGNETIC RESONANCE IMAGING
• Cartilaginous nodules have intermediate signal intensity on T1-weighted images
and high signal intensity on T2-weighted images.
• The addition of intra-articular gadolinium-based contrast material increases the
sensitivity for detecting lesions.
Synovial osteochondromatosis shown on MRI.
A, Oblique axial proton density MR image of
the ankle shows multiple, fairly uniformly sized
bodies (arrow) with low signal rims and
intermediate signal centers.
B, Corresponding T2-weighted image shows
the periphery of the nodules to remain dark,
consistent with calcification or bone, and the
centers of the nodules to remain intermediate
in signal intensity. The joint fluid is very bright
on the T2-weighted image. C, calcaneus; T,
talus.
11. DIAGNOSTIC PROCEDURES
• Arthrocentesis is used to obtain a sample of synovial fluid if the
physical findings suggest infection. The sample is sent for a cell count,
crystal examination, Gram staining, and cultures. All findings should be
within normal limits in primary synovial chondromatosis.
12. TREATMENT
MEDICAL THERAPY
• NSAIDs can be used along with transcutaneous therapies (eg,
ultrasound, thermal therapies) for reduction of inflammation. Patients
do not benefit significantly from nonoperative therapy.
13. SURGICAL THERAPY
• The traditional surgical approach consisted of an open arthrotomy of
the joint, with removal of all loose bodies and either a partial or a full
synovectomy - largely been abandoned now.
• Standard treatment is arthroscopic examination and excision of loose
bodies, with limited synovectomy of involved synovium only.
14. ARTHROSCOPIC TREATMENT PROCEDURE
• The affected leg is surgically prepared to the level of the
tourniquet.
• Standard arthroscopic portals made in the medial suprapatellar
and medial and lateral parapatellar locations
• A 30° arthroscope is inserted through the lateral parapatellar
portal, and diagnostic arthroscopy is performed. Abundant
round cartilaginous bodies, both free in the joint and
embedded in the synovial lining are typically present.
• Arthroscopic graspers are used to remove all free loose bodies.
• Large or pedunculated lesions embedded in the synovium are
excised by using arthroscopic graspers and shavers. A large
outflow cannula is used for extracting loose cartilaginous
pieces.
• Specimens are sent to for histo-pathology.
• Arthroscopic instruments are withdrawn, and portals are
closed, sterile dressing is applied and the knee is immobilized.
Arthroscopic appearance of synovial
chondromatosis loose bodies in the
shoulder.
Arthroscopic shaver during attempted
removal of loose bodies.
Arthroscopic image of pedunculated
synovial chondromatosis in the knee.
15. POSTOPERATIVE CARE
• The patient is discharged with pain medication, deep venous
thrombosis prophylaxis.
• Pathology results are carefully followed up.
• Immediate, full weight bearing is permitted in a knee immobilizer, with
instructions to elevate and apply ice to the knee for the first 3-7 days.
16. FOLLOW-UP
• Follow-up visit 3-7 days after surgery for evaluation of surgical
wounds. Sutures are removed and sterile bandages are applied.
• Physical therapy for full active, active-assisted, and passive range of
motion begins. Full return to activity can be anticipated by 6-8 weeks
after surgery.
17. COMPLICATIONS
• Stiffness and recurrence of mechanical symptoms due to loose-body
generation are most common.
• Repeat arthroscopic surgery were needed in < 20%.
18. OUTCOME AND PROGNOSIS
• In current practice, most authors agree that arthroscopic removal of
loose bodies for mechanical symptoms is the best surgical treatment.
This strategy minimizes postoperative stiffness associated with open
procedures and successfully accomplishes synovectomy and loose
body removal.
19. REFERENCE
• Apley’s System of Orthopaedics and Fractures, 9th Edition
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