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
- abnormal muscle to epitenon
Anatomy
1st dorsal compartment
- over styloid process
- in osseoligamentous tunnel
- shallow groove in styloid
- roofed by dorsal ligament
- attached by fibrous septa to bone
- tunnel ~1cm long
- 20% have 2 compartments
EPB
- phylogenetically young muscle
- found only in humans & gorillas as separate from APL
- EPB absent 5-7%
- inserts base of P1
APL
- larger
- 75% of population has 2 or 3 or more tendinous slips
- varous insertions
- base of 1st MC / trapezium / volar carpal ligament / opponens pollicis / APB
Associations
RA
Pseudogout / Gout
Hypothyroidism
TB
DM
Vascular Disease
OA
Post Trauma
Gout
Pregnancy
Clinical Features
Pain & swelling over styloid
Positive Finkelstein's test
- grasp the patient's thumb / ulna deviation of wrist
Eichoff maneuver
- patient grasps own thumb in fist, ulna deviation of wrist
Crepitus
X-ray
Exclude base of thumb OA
Look for bony spur that may need resection
DDx
Wartenberg's Syndrome
- compression superficial branch radial nerve
CMC OA
Ganglion
Intersection syndrome
- ECRL/B crossed by APL & EPB
Management
Non-operative
Rest
Thumb spica splint
HCLA
Prolonged conservative treatment
- pregnancy, DM etc
Operative
Technique
Transverse / Longitudinal incision
- longitudinal protects nerve
- transverse gives better scar
Identify and protect SRN
Divide Annular Ligament
- ensure all compartments are decompressed
- may be more than one
- make incision ulna side to prevent radial instability
Assess floor of compartment for pathology
Asses for instability
- Z lengthen and repair fascial roof if present
Complications
Very common
- radial nerve neuroma / division
- hypertrophic scar from longitudinal incision
- volar subluxation of tendon if remove too much sheath
- insufficient release