Synovial Chondromatosis

DefinitionSynovial Chondromatosis Knee MRI

 

Chondroid Metaplasia of synovium affecting large joints

 

Nodules of hyaline cartilage

- formed in the subsynovial layer of joint capsules

 

Epidemiology

 

Rare lesion

Most common in 20's and 30's

Sex: M > F (2:1)

Monoarticular

 

Site

 

Any synovial lined joint, tendon or bursal cavity 

 

Marked predilection for large joints 

 

Knee (70%) > Hip > Elbow > Shoulder

 

Subtypes

 

Primary

 

Secondary

- more common

- preexisting OA/RA/AVN/Charcot/TB

 

Pathology

 

Primary

 

Mesenchymal cells in joint capsule (subsynovial layer) become Chondroblasts instead of Fibroblasts

- form nests of cartilage

- nests grow & protrude into joint

- covered by synovium

- eventually become pedunculated into joint

- connected by synovial stalk

 

Then break off & lie free in joint as cartilaginous LB

- Continue to grow in joint 2° synovial diffusion

- can undergo secondary calcification and ossify

 

Secondary

 

Patient with shearing chondral injury

- cartilage cells can seed synovium and continue to grow

 

Patella Chondral DamageSecondary ChondromatosisSecondary Synovial Chondromatosis

 

Histology

 

Central necrotic area that may be calcified

- peripheral ring of viable chondrocytes 

- disorganized chondrocytes with cellular atypia

- can be difficult to pick from chondrosarcoma

 

Stages

Milgram 1977 JBJS

 

Phase 1 - Early; Synovitis, no loose bodies

Phase 2 - Transitional ; Synovitis & loose bodies

Phase 3-  Late ; Loose bodies, no synovitis

 

Clinical

 

Pain & swelling

Loss of ROM

Locking & giving way

Multiple loose bodies

 

X-ray

 

Calcified lesions

 

Loose bodies in suprapatellar pouch

 

MRI

 

Synovial Proliferation

 

Subsynovial masses

- same signal intensity as cartilage

 

Synovial Chondromatosis MRI KneeMRI Knee Synovial Chondromatosis

 

Arthroscopy

 

Synovial proliferation

- localised or generalised

- can see cartilage growing from synovium

 

Multiple loose bodies +++

 

Knee ChondromatosisKnee Chondromatosis

 

Knee ChondromatosisKnee Chondromatosis

 

 

Management

 

Timing

 

Early surgery to prevent secondary degeneration

 

Biopsy

 

Hip

 

Options

 

1. Arthroscopic

 

2.  Open without dislocation

- leave synovium on ligamentum teres

 

3.  Open with dislocation

- lower recurrence

- risk AVN

- Ganz anterior open dislocation

 

Results

 

Boyer et al JBJS Br 2008

- arthroscopic debridement in 111 patients, follow up average 6 years

- 20% required subsequent repeat arthroscopy

- 38% required subsequent open synovectomy

- 20% went on to require THR

 

De Sa et al Arthroscopy 2014

- systematic review of arthroscopic hip debridement

- 7.1% recurrence rate

- minor complication rate 1%

 

 

Lim et al JBJS Am 2006

 

- 21 cases treated with open synovectomy

- 8 treated with arthrotomy alone with 2 recurrences

- 13 treated with surgical dislocation with no recurrences

- recommend dislocation with extensive disease

 

Knee

 

Results

 

Ogilvie-Harris et al Arthroscopy 1994

- 13 patients with generalised disease

- 5 treated with removal loose bodies only

- 8 with synovectomy

- lower recurrence in synovectomy group

 

Shoulder

 

Results

 

Lunn et al JBJS Br 2007

- 15 patients, half primary and half secondary

- arthritic changes present in 8 prior to treatment, 11 after

- arthroscopic synovecotmy + open biceps tenotomy if this area involved

- good pain relief but no improvement in ROM