Self limiting syndrome of unknown aetiology
- hip pain associated with osteoporosis of proximal femur
AVN
- AVN of the hip in pregnancy is rare but possible
- TOH tends to be diffuse on MRI, while AVN is localised
- extends to neck and metaphysis
- transient osteoporosis has normal bone scan
Rare
- M: F 3:1
Non-traumatic or traumatic condition of femoral head with bone death
20 - 50 yo (average 38)
- M: F 4:1
70-80% with AVN will progress within 1 year
Disorder of immune system
- antigen-antibody complexes
- stimulate release of proteolytic enzymes
- leading to vasculitis, synovitis and cartilage destruction
Articular Effects
- synovitis
- ligamentous and capsular laxity
- cartilage destruction
- osseous erosion
Vasculitis
- rheumatoid nodules
6th compartment
- fibro-osseous tunnel overlying 1.5 cm to 2.0 cm of distal ulna
- held tight by the extensor carpi ulnaris tendon sheath
- the extensor retinaculum passes around the ulna to insert on the palmar aspect of the carpus
- extensor retinaculum is a separate structure from the ECU tendon sheath
Forced supination, palmar flexion, and ulnar deviation
Dorsal Intercalated Segmental Instability / CID
Scapholunate joint
- C shaped
- 2-3 mm thick dorsally with transverse fibres
- thin palmar
Dorsal extrinsic ligaments
- V shaped, onto trapezium
Extremely uncommon
Stability provided by joint capsule /costoclavicular & interclavicular ligaments
Recurrent instability uncommon
Many apparent dislocations in adolescents may be growth plate injuries
-will remodel without treatment
If OA from chronic dislocation may resect SCJ
C5, 6 from Upper trunk
Posterior triangle
- arises upper trunk and passes backward through posterior triangle
- under belly of omohyoid
- deep to trapezius to the suprascapular notch
Runs through suprascapular notch
50% rheumatoid patients have elbow pathology
- 80% also have shoulder pathology
- 90% hand and wrist
Always consider entire upper limb
THR in dysplastic hips has a higher failure rate
- due to anatomic abnormalities
- due to generally younger age
Restore normal biomechanics and preserve bone stock
Soft tissues
Deformity characterised by
- dorsiflexion of calcaneus
- plantarflexion of forefoot / plantaris / forefoot equinus
Both sides of foot have elevated arch
Weakness of triceps surae
- polio - most common worldwide
- spina bifida