carpal tunnel.

Steroid injection of the carpal tunnel.

History
One of the most common Orthopaedic conditions, and a large part of our referrals to Hospital.
This diagnosis is often fairly straight forward, however on occasions can be more difficult as the classic symptoms and signs are not present.
Ache, pins and needles in hand. Ask if the pins and needles are more predominant on the thumb side of the hand as opposed to the little finger side. Wakes at night, need to shake /hang hand to relieve night time symptoms, can also cause pain up the arm.

Examination
Occasional wasting of the thenar muscles (base of thumb); this is a late sign. Decreases sensation in the thumb, index, middle and half the ring finger. Weak thumb abduction (lifting the thumb directly up from flat on table).

Special tests
Tinels test:  Tap over the entrance to the carpal tunnel, just proximal to the distal wrist crease. This is where the nerve is most superficial. This will cause pins and needles up the fingers.
Phalen’s Test: Bend the wrist at 90 degrees for 10-30 secs. If positive this recreates their symptoms of pins and needles

Differential Diagnosis

• Cervical spine pathology.
• Higher median nerve compression.

Investigations
I think nerve conduction studies are worth doing on patients for 3 reasons.

• The service at Poole is excellent now, with most tests being done in 2-4 weeks.
• It confirms the diagnosis. Remember however that there is a 10-20 % False –ve. i.e it says that there is no Carpal tunnel, when the patient does have the disorder.
• It gives a good prognostic indicator. If it shows severe compression, then one is able to warn the patient that a full recovery after surgery may not be possible. It also allows a comparison with post operative conduction tests in patients with ongoing symptoms after surgery.

Treatment
From a primary care point of view, treatments which are worth trying include:-

• Splints – These can be very helpful in early disease to allow the patient to get some sleep! A simple Futura splint from the chemist is good enough.
• Steroid Injection – This can be helpful in the short term. Studies however show that 70% who have good response initially have recurrence of symptoms within 1 year. It is however very useful if the diagnosis is not completely obvious. Then I use it not only as a temporary therapeutic tool but also as a diagnostic tool.

When to Refer
If early symptoms, then it is worth treating conservatively (splints at night). However if symptoms are progressive and deteriorating, then the only real option is surgical intervention

How to do a steroid Injection
Please refer to earlier section on steroid injections.

• Blue needle
• 2mls 0.5% marcaine and 20mgs Kenalog
• 1cm prox to distal wrist crease
• Between PL and FCR
• Angle at 45 degrees

Examination
Occasional wasting of the thenar muscles (base of thumb); this is a late sign. Decreases sensation in the thumb, index, middle and half the ring finger. Weak thumb abduction (lifting the thumb directly up from flat on table).

Special tests
Tinels test:  Tap over the entrance to the carpal tunnel, just proximal to the distal wrist crease. This is where the nerve is most superficial. This will cause pins and needles up the fingers.
Phalen Test: Bend the wrist at 90 degrees for 10-30 secs. If positive this recreates their symptoms of pins and needles

Differential Diagnosis

• Cervical spine pathology.
• Higher median nerve compression.

Investigations
I think nerve conduction studies are worth doing on patients for 3 reasons.

• The service at Poole is excellent now, with most tests being done in 2-4 weeks.
• It confirms the diagnosis. Remember however that there is a 10-20 % False +ve. i.e it says that there is no Carpal tunnel, when the patient does have the disorder.
• It gives a good prognostic indicator. If it shows severe compression, then one is able to warn the patient that a full recovery after surgery may not be possible. It also allows a comparison with post operative conduction tests in patients with ongoing symptoms after surgery.

Treatment
From a primary care point of view, treatments which are worth trying include:-

• Splints – These can be very helpful in early disease to allow the patient to get some sleep! A simple Futura splint from the chemist is good enough.
• Steroid Injection – This can be helpful in the short term. Studies however show that 70% who have good response initially have recurrence of symptoms within 1 year. It is however very useful if the diagnosis is not completely obvious. Then I use it not only as a temporary therapeutic tool but also as a diagnostic tool.

When to Refer
If early symptoms, then it is worth treating conservatively (splints at night). However if symptoms are progressive and deteriorating, then the only real option is surgical intervention

How to do a steroid Injection
Please refer to earlier section on steroid injections.

• Blue needle
• 2mls 0.5% marcaine and 20mgs Kenalog
• 1cm prox to distal wrist crease
• Between PL and FCR
• Angle at 45 degrees