Increasing evidence against the diagnosis value of ‘orthopedic’ tests

Facet joints are a common “assumed source” of back pain however NO evidence exists that any test for facet joints is ultimately confirmatory. Kemps-type testing has been proposed to have good sensitivity but that knowledge per se affords no diagnostic prevalence. The effectiveness of common tests is at best “moderate” (Bogduk, Twomey) and only so when multiple tests are used and properly adjudicated (which is still dubious). No one-test can be relied upon. The Slump and SLR do offer insight though both offer confusion thru false-positive & negative results. And confirmation against a “gold-standard” is lacking.  Hancock et al (Eur Spine 07) adds: “conventional investigations do not reveal the cause of LBP”. Even provocative discography has been given a thumbs-down by the American Pain Society official guidelines. Pain researcher Lorimer Moseley on a TED lecture: “You walk into any clinic and see disc models with discs so far out they are sitting on their own…what is your brain to make of that? If you’ve ever seen a cadaver, you CAN’T slip the suckers…they are immobile, they don’t slip…but that’s our language, and it messes with your brain. It cannot NOT mess with your brain”.

An ominous and prophetic conclusory statement has been proffered by numerous researchers: “You (the patient in pain) cannot generally trust professionals to identify a structural origin for your pain…even if you have one, which you probably don’t”.     

Segmental lumbar spine instability at flexion-extension radiography can be predicted by conventional radiography.

Pitkanen MT et al. Clin Radiol Jul;57(7). 2002

An interesting study to identify plain radiographic findings that predict segmental lumbar ‘instability’ as proven via flexion-extension radiography. The ‘instability’ was classified into either anterior or posterior “sliding”.The authors noted: “sliding instability is strongly associated with various plain radiographic findings. In mechanical back pain, functional F/E radiographs should be limited. These findings were strongest for degenerative spondylolisthesis and spondolytic spondylolisthesis. Retrolisthesis, traction “spur” and spondyloarthrosis were all statistically significant with slightly lower odds ratios.

Of course a relatively in depth examination with ‘Form/Force’ closure tests and shear instability checks will give us heightened awareness as to the instability issues in many cases even if radiographs are unavailable. Clearly extensive degeneration, though not linearly related to severity or even frequency of cLBP does clearly play a moderately large role in pain.

Centralization and directional preference…again

Manual therapy 17, 2012 

When we take the time to examine patients’ preferential motions (very often extension and lateral bending) and prescribe them for daily repetition we can typically improve response and reduce therapy dependence or iatrogenic chronicity.

 Centralization is a symptom response to repeated or sustained movements that can be used to classify patients into sub-groups, prognosis and treatment strategies. These facilitated-exercises appear to have an effect in up to 70% of LBP patients with a higher prevalence in acute pain (70%) vs. (44%) in cLBP in studies to date. Studies suggest reliability is good.

The associated but separate phenomenon is that of directional preference which is defined as the “repeated or sustained movements” that induces centralization or abolition of symptoms. Movements in the improvement direction are considered “key” movements, those in the opposite direction considered “locks”. A finding of a directional preference at baseline has been shown to predict a significantly better response to DP exercise than non-specific/generalized exercise movements. Non-centralization was generally a negative predictor of outcome and more likely associated with psychosocial issues.


Lesegue sign a.k.a. straight leg raise

Wikipedia is always an interesting place to learn pointless facts: e.g. Dr. Leseque actually suggested extending the lower leg after the thigh was flexed…NOT the traditional SLR ….Dr. Laza Lazarevic actually described the traditional SLR we typically use today. Both are assumed relevant to determining an L5 (but less L4) disc herniation and/or nerve root irritation. Tests on sensitivity mark it at ~60% and specificity at ~25%.

However several researchers have cross-compared the Slump test with the SLR, and (as discussed in a previous blog as well) the Slump edges out the SLR in terms of eliminating false-positives & negatives, making its specificity nearly 85% and sensitivity at least 90%. Of course so-called odds ratios are compilations of several studies and don’t, in my estimation really give you a lot to actually go on. However doing both the SLR and Slump (a 2 minute time expenditure) will allow a better discussion at our ROF in regard predicting the likelihood the patient requires more extensive interventions or possibly to be put on the “watch-list” for MRI (or surgical consult) if treatment fails to resolve the problem.