subluxation

Definition

Medial subluxation of long head of biceps tendon out of groove and into rotator interval

Definition

Function

LHB primary function is humeral head depressor

Also accelerate / decelerate arm in overhead sports

Problems

Biceps problems usually occur with other pathology 

- rotator cuff / instability

3 main problems

1.  Degeneration

Epidemiology

6 /100 000

- second most common dislocation after shoulder

Mechanism

FOOSH

Goal

Subluxation & dislocation

Diagnosis

Pisotriquetral view

- forearm positioned 30° supinated off the neutral position

- loss of symmetry between the pisiform and triquetrum is required for the diagnosis

- carpal tunnel view may be helpful in further assessment of the joint

Osteoarthritis

Clinical

More common problem

Anatomy

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

Mechanism

Forced supination, palmar flexion, and ulnar deviation

Definition

Stenosing tenosynovitis of the first dorsal compartment of wrist

Epidemiology

Most are middle aged women

Aetiology

Repetitive thumb movements

- abduction & extension

- combined with RD & UD movements

Any mechanical irritation

- foreign body

- prominent bony surface

- restricted fascial compartment

Epidemiology

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