Anatomy
- Tendons of FDS, FDP, median nerve, FPL pass under the flexor retinaculum
- Palmar cutaneous branch of ulnar, PL tendon, ulnar artery and nerve and palmar cutaneous branch of median nerve pass over the carpal tunnel
Demographics
Most common nerve entrapment |
- Females more likely to be affected than males |
- More prevalent in white adults |
- More common in dominant hand |
- Rare in developing countries (work is not as repetitive) |
Risk Factors
- Prolonged wrist flexion/extension |
- Repetitive wrist movements |
- Exposure to vibration/cold |
- Diabetes |
- Hypothyroidism |
- RA |
- Increased BMI |
- Renal disease |
- Thicken transverse ligament |
- Short stature |
- Trauma |
- OA |
- Pregnancy |
- CONSIDER ISCHEMIA (CAD) |
Presentation
- Paraesthesia in palmar 3 1/2 fingers (median nerve) |
- Night symptoms (increased hand volume) - patient complains of having to "wake up and shake it off" |
- Pain over carpal tunnel |
- Patients often think their whole hand is numb (poor localisation) |
- Pain can refer to the elbow |
- Palm symptoms indicate higher up involvement (pronator teres, TOS) as palmar cutaneous branch travels outside of the carpal tunnel |
- Symptoms aggravated by gripping activities |
- Hand weakness/atrophy may occur of the hand (thenar - ape hand) |
- Patient complains of dropping things (decreased sensation) |
- May have autonomic symptoms (tight swollen feeling, skin colour changes, hand temperature changes |
- Hypertonicity of Cx, scalene, pecs, pronator and wrist flexors |
- ROM may not be affected but can reproduce complaint in flexion/extension - consider lunate |
- Limited active thumb abduction |
- Look for cutaneous findings (ulcerations, blistering, sclerodactyly, nail dystrophy) |
- +ve Tinels, Phalens , Manual Carpal compression (most sensitive) |
- Numbness of 5th digit/dorsum , consider neuropathy of alternate origin |
- Weakness in LOAF muscles (1st and 2nd lumbricals, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis) - Pinch grip |
- Consider double crush - Cervical arthropath, Cx disc, TOS, Pronator syndrome |
- Consider other structures - ligament of Struthers, lacertus fibrosis |
Bilateral hand involvement - central cord lesion until proven otherwise (MRI) |
CPR
Least 4 of the 5 findings: |
Shaking hands to relieve symptoms |
Wrist rate >.67 (thickness to the width) |
Symptom severity scale >1.9 |
Diminished sensation in thumb |
Age >45 years old |
Imaging
- Imaging only needed if bony compression is suspected |
- MRI can be used to determine Cx radiculopathy/soft tissue pathology |
- US (more sensitive than MRI) |
- EMG |
DDx
- Cx radiculopathy |
- TOS |
- Compartment syndrome |
- Diabetic neuropathy |
- Lateral/medial epicondylitis |
- MS |
- Regional pain syndrome |
- SOL - Flexor tenosynovitis/ganglions |
Management
- Myofascial release of forearm, wrist and hand - pronator, wrist flexors and carpal tunnel |
- Median nerve flossing |
- SMT of Cx or carpal restrictions |
- Kinesiotape |
- Splinting (night pain) |
- Home exercsies - Cx spine, scalene, pecs, pronator and wrist flexors, chin retraction, carpal tunnel mobilisation, median nerve glide and floss |
- Advise rest - avoidance of repetitive wrist flexion/extension |
- Vitamin B6 |
- Weight loss if obese |
- Patients with significant motor deficits/not improving with conservative care consider referral for injections/surgery |
Factors of success of conservative care:
1.Age >50 years
2. Duration >10 years
3. Constant paraesthesia
4. Stenosing flexor tenosynovitis
5. +ve Phalens test in >30 seconds
>2 factors - conservative management successful in 83% of cases
if 3 - 7% success
if 4 or 5 - 0% success
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