Complex Regional Pain Syndrome

Chronic progressive condition characterized by severe pain, swelling, and skin changes.

Subtypes

• Type 1 (AKA RSD) : not associated with nerve injury, but may be associated with other trauma –
• Type 2 (AKA causalgia): associated with nerve injury

Both types:

• spontaneous pain or allodynia not limited to single peripheral nerve distribution — disporportionate to inciting event.
• history of edema, blood flow abnormality, abnormal sweating.
• no better explanation exists.

Pathophysiology

• upregulation of NMDA receptors
• elevated glutamate levels
• immunogenic
• cytokine release
• neurogenic inflammation
• adrenoreceptor pathology
• sympathetic afferent coupling
• …etc.

Epidemiology

• 3:1 female predominance
• most common in 4th decade, but wide variation in age range affected.
• 2-5% of patients with a peripheral nerve injury

Symptoms

• at site of a previous injury (of varying severity)
• spread beyond site of original injury.
• most commonly burning pain
• also muscle spasms, local swelling, joint tenderness / stiffness, nail and skin changes.
• allodynia / hyperalgesia
• eventually disuse atrophy and stiffness.

Stages

1. Type one is characterized by severe, burning pain at the site of the injury. Muscle spasm, joint stiffness, restricted mobility, rapid hair and nail growth, and vasospasm.
2. Type two is characterized by more intense pain. Swelling spreads, hair growth diminishes, nails become cracked, brittle, grooved, and spotty, osteoporosis becomes severe and diffuse, joints thicken, and muscles atrophy.
3. Type three is characterized by irreversible changes in the skin and bones, while the pain becomes constant and may involve the entire limb. There is marked muscle atrophy, severely limited mobility of the affected area, and flexor tendon contractions.

Diagnosis is primarily clinical, but adjuncts are:

• thermography
• sweat testing
• radiography – patchy osteoporosis;  bone scan, bone densitometry
• electromyopgraphy (for type II)
• nerve blocks

Treatment

• PT/OT: desensitization, mobilization
• Medication: GABA agonists, steroids, antidepressants, NSAIDs
• nerve blocks
• neurostimulation
• sympathectomy
• ketamine

Collagen tubes for digital nerve

Retro review
12 patients
9 have outcomes data. 12-22 months

2pt: good/excellent 8/9
SW: 5 full/ dim lt touch 2 / dim prot.sens 1 / loss prot. Sens 1

BG: collagen vs PGA tubes avail.
PGA tubes have head to head comparison with primary repair and grafting. – weber 2000 randomized trial

Mat. & Methods:
2 yr period
2pd, sw, qdash
Seg loss 1-2 cm
Ci’s : infx, contam, systemic instability, primary repair possible w/o tension

Blinded evaluation
8 men 4 women. Avg 33yo
Hand dominance 50/50
4 isolated nerve injury 8 multiple trauma
2 f/u < 1yr
1had subsequent amputation
Avg fu 15 mos for remaining 9

Technique: 20 mm tubes, saline, 8-0 or 9-0, epineural
Post-op: std sensory reeducation protocol
Tt80avg. Surg time 140 avg

Discussion:

Promising results
Sensory model only (no motor nerves)
? Similar to primary nerve repair and repair with autograft?

Small size, 3 Pts lost to fu
No comparison cohort: primary repair/ repair with graft

Discussed other studies
Lohmeyer
Inada
Meek

The bow of the radius

“it has a slight lateral convexity or bowing.”
“the body is concave anteriorly in its proximal three-fourths and flattened in its distal one-fourth.”

• Clinically oriented Anatomy. 3ed  KL Moore p.555

Saturday run

june 14
Find more Runs in Saskatoon, Saskatchewan

running log

univ bridge to idylwyld loop
Find more Runs in Saskatoon, Saskatchewan

Parallel Blog.

I started posting notes on a parallel blog: orthoreview.wordpress.com

Principles of Tendon Transfer

1. correction of contracture
2. adequate strength
3. adequate amplitude (3/5/7 rule at hand & wrist)
4. straight line of pull — artificial pulleys always attenuate
5. 1 tendon : 1 function  (exception is FDS insertion allows natural split to 2 insertions — but definitely a fiddle)
6. synergism
7. expendable donor
8. tissue equilibrium

N.B. timing of transfers.

3 key questions:

1. What function is missing?
2. What can be sacrificed?
3. What does the patient need?

probability – the briefest possible review.

• P(event A) = relative frequency of Event A / large number of events (where A is possible)
• Conditional Probability = p(a) given that b has already happened.  P(a|b)
• independent events: event b has absolutely no effect on P(a).  P(a)= (a|b)
  • if a and b are independent, P(A & B) = P(B)P(A)
• dependent events : P(a) is not the same as P(a|b)
• mutually exclusive events : if b occurs a cannot (and vice versa)  P(a|b) = 0.  
• if A & B are mutually exclusive then P(A or B) = P(a) +P(b).

Biostatistics and Epidemiological Methods

Relative Risk = ratio of rate of disease in those exposed to that rate among those not exposed.

•  e.g. RR(lung CA) = rate of lung CA in smokers / rate of lung CA in nonsmokers

Attributable Risk = rate of disease in exposed – rate of disease in non-exposed

Controlled Clinical Trial

•  prospective study
• split participants into 2 groups (usually randomly) – give each group different Rx
• assess results and compare between groups.

Prospective Observational Study Design (cohort study design)

•  answers the question of whether a particular factor is a causal factor for a given condition.
• difference between this and controlled clinical trial is that the 2 groups are not selected by the investigator (they are selected based on presence or absence of the factor in question)
• it is prospective
• the groups are usually not comparable in several aspects.

REtrospective Study Design

•  AKA case-control study design
• identify 2 groups (one affected, the other not) that are identical in all other ways
• look back into past to try to identify causal factors.

Cross-Sectional Surveys

•  does not involve the time factor.
• “snapshot” at one moment in time.
• can determine association of 2 factors, but not causation

Advantages of Retrospective Design over Prospective

•  prospective inefficient in diseases with low incidence rates.  (lots of $$, time, energy spent on following up cases that don’t develop disease in question)
• retrospective study has ability to yield results quickly (prospective usually requires extended follow-up)
• prospective studies suffer loss of patients during follow-up (distortion of results)

Advantages of PRospective over REtrospective

•  direct estimate of incidence rate
• problem of historical data (recall bias)
•  cannot identify time sequence of factors.  (sometimes)

In case of no pulse…

Here’s the ACLS Algorithm (2005)