Synoviochondrometaplasia & Neuropathic Arthropathy (DRAFT)

Question 1

What are alternative names for Synoviochondrometaplasia?

Answer 1

(SCM) Synovial osteochondromatosis
Synovial Chondromatosis

Question 2

what is SCM?

Answer 2

creation of osteochondral loose bodies inside the joint capsule

Question 3

what are the forms of SCM?

Answer 3

Idiopathic: primary SCM (grows off synovial villi)
Degenerative: secondary SCM (2* to a degenerative process)

Question 4

what are the pathologic features of 1* SCM?

Answer 4

• synovium undergoes metaplasia, forms exuberant synovial villi
• ends of villi form cartilage bodies, which can eventually ossify +/or break free

Question 5

what are the pathologic features of 2* SCM?

Answer 5

degeneration results in cartilage flaking off. flakes act as accretion site and continue to grow
- can eventually ossify

Question 6

what are the clinical features of SCM?

Answer 6

non-specific
- joint pain
- swelling
- crepitus
- locking

Question 7

what is the #1 symptom of SCM that actually correlates ~specifically?

Answer 7

joint locking

Question 8

what are the preferential locations of SCM?

Answer 8

70% knee MC
- hip
- shoulder
- elbow
- ankle
-wrist

Question 9

what is the #1 cause of jt locking in the knee?

Answer 9

meniscal tear

Question 10

what are the radiographic features of 1* SCM?

Answer 10

• loose bodies w/ similar size + shape (only seen if ossify)
• none-mild degenerative change (early in disease; 1* SCM can create degeneration
• 1-100s of loose bodies

Question 11

what is the treatment for 1* SCM? what are the consequences and subsequent management of this treatment?

Answer 11

Loose body resection
Synovectomy: synovium lining must be removed to prevent recurrance
- no synovium = decrease imm. function, decrease lubrication, and increase degeneration
- lubricant injection every 6 months (glucosaminoglycan)

Question 12

what are the radiographic features of 2* SCM?

Answer 12

• loose bodies w/ different size + shape (only seen if ossify)
• pre-exisiting moderate to severe degenerative change
• 1-10 loose bodies

Question 13

what is the treatment for 2* SCM?

Answer 13

conservative management, NSAIDs
Arthroscopic loose body removal: vacuuming out loose bodies (degeneration isn’t of concern b/c pre-exists)

Question 14

what is another name for Neuropathic Arthropathy?

Answer 14

(NA) Charcot Joint

Question 15

What is Neuropathic Arthropathy?

Answer 15

progressive joint destruction secondary to a neurological disorder

Question 16

what are some neurological disorders that may result in neuropathic arthropathy?

Answer 16

• Peripheral neuropathies (no pain sense –> stocking & glove anesthesia); eg. diabetes mellitus, alcholism, MS, Charcot-Marie-Tooth disease
• Central motor abnormalities; eg. neuro syphilis aka 3* syphilis (uncommon)
• Syringomyelia (relatively common)
• Iatrogenic cases
• Hanson disease aka Leprosy

Question 17

what is the preferential location of Neuropathic Arthropathy?

Answer 17

weight-bearing joints MC:
- lumbar
- knee
- foot/ankle

Question 18

what is the preferential location of Neuropathic Arthropathy when secondary to Syringomyelia?

Answer 18

shoulder & UE joints

Question 19

what is the pathogenesis of neuropathic arthropathy?

Answer 19

• abnormal joint mechanics
• possible alterations in vascular supply

Question 20

what are the 2 forms of Neuropathic arthropathy?

Answer 20

Hypertrophic & Atrophic

Question 21

what is Hypertrophic Neuropathic Arthropathy?

Answer 21

rapid + severe secondary joint degeneration
- progressive articular & subchondral bone destruction is accelerated by lack of pain + proprioception

Question 22

what is Atrophic Neuropathic Arthropathy?

Answer 22

resorption of bone
- tapered bone ends, missing parts (atrophy of bones)

Question 23

what are the clinical manifestations of Neuropathic arthropathy?

Answer 23

• altered joint biomechanics / gait (eg. slapping or stomping)
• pain insensitivity; painless instability
• joint enlargement / swelling w/ warmth
• crepitus
• symptoms worsen over weeks, months, years
• “bag of bone” appearance
• “surgically amputated” appearance

Question 24

what are some buzz word terms used in describing the clinical presentation of neuropathic arthropathy?

Answer 24

“Bag of bone”
“Surgically amputated”

Question 25

what neumonic can be used when describing the clinical presentation of Hypertrophic NA? what is required for diagnosis?

Answer 25

6 D’s (3 Di words, 3 De words); require minimum of 3 D’s to diagnose
- Distension
- Dislocation
- Disorganization
- Density (subchondral sclerosing)
- Debris
- Destruction

Question 26

what are the clinical presentations of Atrophic NA?

Answer 26

(vascualr component)
- tapered distal margins of bones: “licked candy stick” appearance
- surgically amputated appearance

Question 27

what buzz word term is used exclusively in describing Atrophic NA?

Answer 27

“licked candy stick” appearance
- likely in diabetics (the irony lol)

Question 28

what is the MC cause of neuropathic arthropathy?

Answer 28

diabetes

Question 29

what is the most clinically significant component of Synoviochondrometaplasia?

Answer 29

joint locking w/ eventual joint destruction

Question 30

what is the clinical significance of OPLL?

Answer 30

central canal stenosis w/ SC compression