Simon Richards

orthopaedic surgeon

 
 

your Specialist in conditions

 

of the arm & hand

 

Steroid injection of a trigger finger

History
A very common hand condition.
Caused by a nodule over the flexor tendon, which catches at the entrance of the flexor pulleys (A1 pulley).
Patients initially complain of a painful click at the base of the finger or thumb on the palm, which ultimately leads to the finger being “stuck” in a flexed position at the PIP Jt, most commonly in the morning. They have to push it out straight, which is painful..
Trigger finger is more common in diabetics, who often have multiple fingers affected.

Examination
Often a painful nodule can be felt under the distal palmer crease, which moves when the finger moves.

Differential diagnosis

  • Pseudo triggering. This is a problem of the MCP joint on the dorsum of the hand. The extensor tendons falls into the ulna sided gutter, causing the finger to lock. This is at the MCP joint and not the PIP Joint, and the pain is dorsally. Beware this diagnosis especially in the elderly.
  • Tenosynovitis.  Triggering can also be a manifestation of flexor tendon sheath inflammation, especially in the Rheumatoid patient.

Investigations
There are no specific investigations needed for simple trigger finger.
If however there is a concern that there may be tenosynovitis, then an ultrasound scan can be helpful.

Treatment

  • If minimal problems associated. then it can be treated conservatively.
  • The mainstay of treatment is a steroid injection. This is curative in around 80% of patients with up to 2 injections. Less if the finger is permanently locked and in diabetic patients.
  • If injections have failed, or if the patient is not keen on injections, then referral for surgical release is indicated.

When to refer
If you are happy to carry out injections, then I think this should be the first treatment option in symptomatic trigger finger. If this fails then refer on. If the injection works fully or partly and then the triggering returns, than a second injection is warranted if clinically required.

Injections 
Please refer to section on steroid injections for further information.

What’s the Evidence ?
Marks et al  JHS 1989. 84% success rate of trigger fingers and 92% trigger thumbs after single injection of Kenalog at 3.5 yrs

How to Inject

  • Better outcome in women, worse outcome in IDDM and multiple fingers
  • Blue needle
  • 1ml Lignocaine and 10-20mgs Kenalog
  • Distal palmer crease
  • 45 degrees
  • Aim for metacarpal head

Fig 1. Steroid injection of the 1st CMC Jt (between the 1st metacarpal and trapezium)

Fig 2. Steroid injection of the 1st CMC Jt (between the 1st metacarpal and trapezium)

History
The 1st Carpometacarpal joint (1st CMC Jt) is one of the most common areas of symptomatic arthritis especially in post-menopausal women. Present at @50-70 yrs. Often a positive family history of mum/sister/grandmother having had a similar problem.
Complain of pain @ base of thumb, but also in the thenar eminence and up the thumb. Poor grip causes difficulty in opening jars etc.

Examination
The thumb base can be swollen and prominent. The thumb often becomes adducted into the palm secondary to the subluxation at the 1st CMC Jt. With the thumb stuck down in the palm, over time, the metacarpo-phalangeal joint (MCP) becomes hyper-extended due to compensation. This is the classic “Z” deformity that can occur in chronic conditions.
Palpation is painful at the 1st CMC jt and circumduction and compression (the “Grind” test) is painful.

Differential Diagnosis

Other causes of radial sided wrist/thumb pain include

  • De-Quervains tenosynovitis
  • STT Jt arthritis. This is the joint below the 1st CMC Jt and should always be checked for arthritis
  • Sequaele of scaphoid fracture, including non-unions and arthritis
  • Ganglions

Investigations
Plain Radiographs will confirm the diagnosis. The views which are needed are a Roberts view (true AP – forearm in maximal pronation & dorsum of thumb resting on the x-ray cassette) and a lateral.

Treatment
The therapeutic ladder is the best way to treat this condition, as in any arthritic joint condition:-

  • Activity modification
  • NSAID
  • Splints- the therapists at Poole and Bournemouth Hospitals will be happy to make a thermoplastic custom splint for your patient
  • Steroid injection, see below
  • Surgery:-

1.    Extension metacarpal osteotomy – only rarely used
2.    Arthroscopic 1st CMC Jt debridement – very rarely used
3.    Trapeziectomy – the main stay treatment for most surgical patients
4.    1st CMC Jt fusion – best in manual working men
5.    1st CMC Jt replacement – only in relatively young patients with a well preserved STT Jt. Long term results are not known

When to Refer
A large number of patients can be successfully treated in primary care with the non-surgical techniques above.
If symptoms continue after a period of months of conservative measures then referral is suitable.
Patients need to know that surgical techniques are successful in the majority of patients, but post operative rehabilitation is lengthy and can take up to 4-6 months to reach full benefit.

Injections 
Please refer to section on steroid injections.

What’s the Evidence ?

  • Day et al JHS 2004 29A
  • Randomized control trial. Comparing placebo to steroid.
  • Good results with steroid injection if early OA.
  • Poor results with more severe OA. i.e early recurrence

It’s my opinion that a maximum of 2 injections in a treatment cycle (i.e 1 year) is allowed. Too many lead to skin and fat atrophy which makes surgery more risky.

How to Inject

  • Blue Needle
  • 1-2 mls lignocaine, 10-20 mgs Kenalog
  • Apex of snuff box, Pull thumb
  • Don’t worry about not getting needle into centre of joint, if it’s within the capsule of the joint then the steroid will hit the spot

Steroid injection for tennis elbow at the lateral epicondyle.

History
Causes lateral elbow pain that is activity related, and due to the mechanical overload of part of the common extensor tendon origin (the ECRB or extensor carpi radialis brevis, which is a wrist extensor muscle).
Pain may radiate to the wrist.
Most common diagnosis in a patient with elbow pain.
4:1 men, aged 30-50.

Examination
Tenderness over anterior/inferior lateral epicondyle.
Provocative test= pain on resisted wrist extension (with elbow extended). Almost always present in this condition. If not, then think of another diagnosis.

Differential Diagnosis

  • Radial Tunnel syndrome. Pain slightly more distally away from lateral epicondyle.
  • Biceps tendinitis. Pain on elbow flexion and supination.
  • Elbow arthritis. Often crepitus noted in elbow on movement.
  • Rule out more proximal pathology from neck and shoulder.

Investigations
Usually a clinical diagnosis.
MRI scan if symptoms and signs are not fully clear to make a diagnosis.
X-Ray of elbow to rule out arthritis.

Treatment
50-70 % get better over a period of 6-18 months with conservative treatment, which includes;-

  • Activity modification. Stop doing activities which cause it.
  • Medication. NSAID’s
  • Steroid Injection. See below for further information.
  • Splints. Wrist extension splint – protects the ECRB – Counterforce brace (tennis elbow clasp) – spreads load at the elbow.
  • Physio. Can be very helpful. Includes ultrasound, strengthening programmes, acupuncture.
  • Surgery. Only consider after at least 9/12 of the above. – Success rate of around 80%. – Can take up-to 6-9/12 to gain full affect. Warn patient.
  • Stem Cell Injection. A newish technique, which has good preliminary results with low complication rate and quicker rehab than open surgery. 60-70% successful.
  • Shockwave therapy. A technique where sound waves are passed through the area, leading to an inflammatory response, and resolution of symptoms over a 2-4 month period. 60 -70% successful.

When to Refer

  • If diagnosis is not fully clear.
  • If conservative treatments have failed after a period of 6-9/12.

Injections
Please refer to section on steroid injections.

What’s the Evidence?
BMJ 1999 319. 964
164 pts into 3 groups (steroid injection, NSAID, Placebo)
Steroid better at 1 month.
NSAID, Placebo slightly better at 6 months
No difference at 1 year

Cochrane Review of 13 studies
As above, good for short term improvement, no difference in longterm.

It’s my opinion that a maximum of 2 injections in a treatment cycle (i.e 1 year) is indicated. Too many lead to skin and fat atrophy which makes surgery more risky.

How to Inject

  • Blue Needle
  • 2mls Lignocaine, 20mgs Kenalog
  • Aim for anterior facet of lateral epicondyle
  • Pepper pot technique (i.e multiple movement around the epicondyle during injection). This spreads the injection, but also causes bleeding which is good (as leads to scar tissue)
  • Rest for a week post injection.

Corticosteroids effects can be divided into Glucocorticoid and Mineralcorticoid activity. It’s the Glucocorticoids which have the anti-inflammatory effect. In my Practice, I use Triamcinolone (Kenalog) because:-

  • More flexibility in dosage
  • More soluble in local anaesthetics
  • Less pain after injection

However Methylprednisolone (Depomedrone) is perfectly suitable to use as well (double the dose when compared to Kenalog).

Side-Effects
Arise when:-

  • Too large a dose is used
  • Inappropriate drug is used
  • Injections given too frequently
  • Poor injection technique

Systemic Effects

  • Flushing
  • Menstrual irregularity
  • Glucose intolerance

Local Effects

  • Post injection flare (unavoidable)
  • Infection
  • Skin atrophy, depigmentation and discolouration, tendon  rupture (Poor technique)

Dosages
This is a summary of the dosages I use for specific joints. I also incorporate/mix some local anaesthetic, usually 0.5% Marcaine, within the syringe to make up the final volume.

 Joint Volume (ml)  Kenalog (mg)
 Shoulder  10  40
 Hip  10  40
 Knee  10  40
 Elbow  5  20
 Ankle  5  20
 Fingers  1  10-20
 Wrist, Thumb  2  10-20

Please see conditions listed in the menu above for advice on how to inject specific anatomical areas.

The number and range of investigations available to primary and secondary care is enormous.
There is a feeling that it is almost too easy these days to send a patient off for a scan, without fully assessing the patient and making a differential diagnosis purely from the history and examination. I think we are all guilty of this.
However investigations are vital in confirming, or not, our provisional diagnosis, assessing in detail the pathology, and aiding the planned treatment.

I will list below the most common investigations in my Orthopaedic practise, how they work and when to use.

1. X-rays
Almost all Orthopaedic patients with a bone, joint or soft tissue problem should have a base-line X-ray. Two Orthogonal (at 90 degrees) views should be taken in most cases.
Specific anatomical examples in my practise include:-

  • Hand – AP, lateral  and 30 degree Oblique views
  • Thumb Base – Roberts view (True PA) and lateral
  • Scaphoid – 4 view scaphoid series
  • Wrist – Standardised PA and lateral
  • Elbow – AP and lateral
  • Shoulder – True AP, axillary lateral (or Y scapular instead)
  • Hip – AP pelvis
  • Knee – AP and lateral (must be weight bearing views)

2. Ultrasound Scans
An ultrasound probe emits high frequency sound waves that are passed through the body area being studied. These waves are reflected back by the structures inside and the echoes are used to form an image. The harder the structure they hit, the stronger the echo.
Thus fluid gives no image, while bone gives a very strong image.
Doppler ultrasound is similar, but also gives an idea of blood flow in the area.
Examples of conditions where ultrasound is useful include:-

  • Any tendon inflammatory disorder (De-Quervains)
  • Any Fluid filled lump (Cysts)
  • Shoulder impingement

3. Computer Tomography
A CT uses X-rays to form an image. Instead of a single X-ray, as used in a normal radiograph, CT uses multiple X-ray beams at different angles. The beams pass through the body area and are picked up on the other side. The signal is then turned into an image by the computer. These images can be manipulated into 3-D images.
CT in Orthopaedics is best for looking at bony anatomy.
Examples of conditions where CT is useful include:-

  • Fractures, especially non-unions e.g scaphoid

4. Magnetic Resonance Imaging (MRI)
Radiowaves are sent through the body. These excite the protons in the cells and push them into a different position. As these protons move back into their normal position, they give off their own radiowaves. These are picked up by the scanner and turned into an image.
There are many different sequences that can be used in MRI. The two most common are:-
T1 = This image shows fat as a bright image and fluid as a dark image. As a rule of thumb this image is useful in seeing anatomy.
T2 = This image shows up water (or any fluid) as very bright. It is therefore useful in looking at inflammation, cysts etc. As a rule of thumb this image is useful in seeing pathology.
N.B an aide-memoire is Water = H20, thus T2 (easy!)
Examples of conditions where MRI is useful include

  • Any soft tissue lesion
  • Any tumour

5. Nerve conduction studies (NCS)
This is the study of peripheral nerves and the muscles they supply.
NCS look at the two functions of peripheral nerves, sensation and muscle stimulation.
The motor component is performed by electrical stimulation of a peripheral nerve and reading the effect in the muscle further down the limb supplied by that nerve. The time taken to travel that distance is measured, as well as the reaction of the muscle.
The sensory component is similarly performed, but the measurement is taken at a purely sensory spot (e.g the tip of the finger).
This will therefore show if there is a block or a slowing to the impulses travelling down that nerve at a specific spot e.g the carpal tunnel.

6. Blood tests
A number of blood tests are useful in certain orthopaedic conditions

A). Infection = FBC, ESR, CRP
B). Inflammatory Arthritis = FBC, ESR, Rheumatoid factor, ANA (anti-nuclear antibodies)

Fig 1. Steroid injection for golfers elbow at the medial epicondyle.

Fig 2. Steroid injection for golfers elbow at the medial epicondyle.

History
Causes medial elbow pain that is activity related, and due to the mechanical overload of part of the Common Flexor Tendon Origin (mainly the origin of the Pronator Teres and Flexor Carpi Radialis); these muscles pronate and flex the wrist and forearm.
1/3 as common as tennis elbow. Only 10% of patients are golfers !
4:1 men, aged 30-50.
50% have associated ulnar nerve symptoms (cubital tunnel syndrome). Always ask about pins and needles symptoms.

Examination
Tenderness over anterior medial epicondyle facet.
Provocative test= pain on resisted forearm pronation with elbow extended, or pain on resisted wrist flexion.
Test the ulna nerve (see cubital tunnel information)

Differential Diagnosis

  • Biceps tendinitis. Pain on elbow flexion and supination.
  • Elbow arthritis. Often crepitus noted in elbow on movement.
  • Rule out more proximal pathology from neck and shoulder.

Investigations
Usually a clinical diagnosis.
MRI scan if symptoms and signs are not fully clear to make a diagnosis.
X-Ray of elbow to rule out arthritis.
Nerve conduction studies if concern about ulnar nerve.

Treatment
50-90 % get better over a period of 6-18 months with conservative treatment, which includes

  • Activity modification. Stop doing activities which cause it.
  • Medication – NSAID’s
  • Steroid Injection – See below for further information.
  • Splints – Wrist flexion splint – protects the FCR, Counterforce brace (golfers elbow clasp) – spreads load at the elbow.
  • Physio – Can be very helpful. Includes ultrasound, strengthening programmes,  acupuncture.
  • Surgery – Only consider after at least 9/12 of the above. Success rate of around 70-90%. Can take up-to 9/12 to gain full affect. Warn patient.
  • Shockwave – This technique utilises sound waves passed through the painful area to set in process an inflammatory response which in turn settles the symptoms down via the bodies natural healing process. Success rate is in the order of 60-70%.
  •  Stem Cell Injection. A newish technique, which has good prelimary results with low complication rate and quicker rehab than open surgery.

When to Refer

  • If diagnosis is not fully clear.
  • If conservative treatments have failed after a period of 6-9/12.

Injections
Please refer to section on steroid injections.

How to Inject

  • Blue needle
  • 2mls Lignocaine, 20mgs Kenalog
  • Aim for anterior facet of medial epicondyle
  • Pepper pot technique (i.e multiple stabs/movements around the epicondyle during injection). This spreads the injection, but also causes bleeding which is good (as leads to scar tissue)
  • protect ulna nerve (and check it is not situated infront of the epicondyle, which can rarely be the case)
  • Rest for a week

History
Patients present with a lump in the palm and curled fingers, most commonly ring and little. Often bilateral, and affects the thumb side of the hand more commonly in Diabetics.
A positive family history should be looked for, and is the most common association. Associations with alcohol, epilepsy etc are worth looking for.
If the patient is young, then think about Dupuytrens Diathesis, which is severe Dupuytrens affecting not only the hands, but also the feet (Lederhosen’s disease) and the penis (Peroni’s disease).

Examination
Often nodules and cords can be felt passing from the palm to the affected finger. The MCP (knuckle) and PIP joints are the most commonly affected. Look for Garrods pads on the back (dorsum) of the PIP joint.
Finger flexion and neurological state should be normal.
Ask the patient to do the table top test. If they can flatten the fingers and palm to a flat surface, then surgery is probably not warranted.

Differential diagnosis

  • Post traumatic joint contractures
  • campylodactyly – congenital cause for a bent finger

Investigations
There are no specific investigations required to help with the diagnosis.

Treatment

  • If minimal contracture and no functional loss, then conservative treatment is worth pursuing.
  • If symptomatic then the options include needle fasciotomy (good for MCP contractures only), Collagenase injections (a new enzyme treatment, again best for MCP contractures) or surgical removal and release (fasciectomy or dermofasciectomy).
  • Studies have shown no beneficial help from treatments including steroid injections, radiotherapy, ultrasound, physiotherapy, splints etc

When to refer
I have a rule of thumb that if the MCP Jt is contracted by more than 40 degrees and the PIP Jt by more than 20 degrees, then treatment is worth considering.
More severe contractures than this, especially in the PIP Jt will have a less successful surgical outcome.
Any young patient with disease should be referred early even if contracture is relatively mild.

Steroid injection of the 1st extensor compartment for De-Quervains tenosynovitis.

History
De-Quervains is a common cause for radial sided wrist pain.
It’s a stenosing tenovaginalitis of the 1st extensor compartment (containing Abductor Pollicis Longus and Extensor Pollicis Brevis).
It is more common in women, especially after birth of a child. 30-50 yr olds.

Examination
Pain and Swelling on the radial side of wrist, 1-2 cms proximal to radial styloid.
+ ve Finkelsteins test = pain with thumb in palm, fingers wrapped over and wrist ulna deviated.

Differential Diagnosis

  • Thumb base arthritis. Pain and crepitus 2 cms distal to radial styloid.
  • Intersection syndrome. Pain 4 cms proximal to radial styloid

Investigations
Normally a clinical diagnosis. Ultrasound can be helpful in showing fluid in the 1st extensor compartment, as well as tendon sheath thickening and restricted tendon glide.

Treatment
As with all conditions, start with simple treatment options and work up the therapeutic ladder as required.

  • Activity modification
  • Splint – Ask the therapists to supply a splint in slight extension and thumb abducted (out of the palm). Usually only short term relief.
  • Steroid injection – See below
  • Surgical release of 1st extensor compartment.

When to refer
Attempt at conservative management is definitely worth trying initially. A fairly large proportion can be treated successfully with rest, splints and injections.

Injections
Please refer to earlier section on steroid injections.

What’s the Evidence ?
Saki et al
 Orthopaedics Jan 2002:- 53 Patients, 46 have relief after 1 injection, 6 more after 2, 1 more after 3.  i.e everyone successful. Lower rate of success in diabetics.

How to Inject

  • Blue needle.
  • 1-2mls 0.5% marcaine, 10-20 mgs Kenalog.
  • Pt abducts and extends the thumb. Note where the 2 tendons disappear into the extensor tunnel. This is where you inject.
  • Level of Radial styloid and aim distal to prox.

Compression of the ulna nerve as it passes through the Cubital tunnel behind the medial epicondyle.

Compression of the ulna nerve as it passes through the Cubital tunnel behind the medial epicondyle.

History
2nd most common peripheral nerve entrapment, after carpal tunnel syndrome.
50-70 % idiopathic. Other causes include trauma, ganglion.
Most common in men.
Present with pins and needles/altered sensation in the little and ring finger. Symptoms aggravated by flexion of the elbow. May complain of elbow pain/ache on the inner aspect.

Examination
Tenderness over nerve at the elbow, behind the medial epicondyle.
Loss of sensation in the ulna 1 and 1/2 fingers.
Weakness in little finger abduction (away from the ring finger).
Loss of muscle bulk in the 1st dorsal interrosei muscle (between thumb and index finger).

Special tests
1.Tinel’s Test at the elbow. Tapping on the nerve causes the symptoms in the hand.
2.Wadsworth’s Test. Flexing the elbow to 90 degrees causes the symptoms at the wrist and hand. This is due to flexion narrowing the cubital tunnel by over 50%

Differential Diagnosis

  • Cervical root lesion.
  • Thoracic outlet syndrome.
  • Guyons canal compression of the ulna nerve (at the wrist).
  • Double crush phenomenon. Cubital tunnel syndrome as well as another nerve compression

Investigations
I think nerve conduction studies are worth doing on all 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 5-10 % False –ve. i.e it says that there is no Cubital tunnel syndrome, 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 if post operative conduction tests are carried out in patients where there is a concern that they still have symptoms, even after surgical decompression.

Treatment

  • Conservative. If symptoms are short lived and relatively mild then watch and wait is an option.
  • Splints. These can be helpful if mild symptoms. Elbow should be kept at around 45 degrees. Wrist should be included as the ulna nerve can be trapped by one of the wrist flexors at the elbow (Flexor Carpi Ulnaris muscle).
  • Steroid injection. No real role  in this condition. Does not help and may lead to problems including painful fat atrophy.
  • Surgery. Most persistent cases require surgery. Simple decompression of the nerve leads to around 80% success. But patients with severe compression may not do well, and any improvement can take a year to fully occur. MAin reason to undertake the procedure in these patients is to stop symptoms getting any worse.

When to Refer

  • Any concern of the diagnosis
  • Persistent moderate symptoms.
  • Any patient with severe symptoms

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