Objective:

Identifying a spinal source for isolated extremity joint pain that appears seemingly unrelated can be a diagnostic challenge (i.e., trying to determine if a patient with isolated knee pain is experiencing referred pain from the lumbar spine with the knee joint itself not being the source of pain). Establishing prognostic indicators from the history or physical examination could assist in the decision-making process by helping clinicians to evaluate the extent of the need for more thorough spinal movement screening in patients with isolated extremity joint pains. The objective of this study was to identify clinical indicators that predict whether patients with isolated lower or upper extremity pain have a spinal or extremity source of pain as classified by Mechanical Diagnosis and Therapy (MDT) trained clinicians.

Design:

Is a secondary analysis, exploratory study of a previous prospective cohort study (Rosedale et al 2019)

Results:

Five indicators were identified to predict group classification. Classification into the spinal group was associated with:

The presence of paresthesia [odds ratio (OR) 1.984]
Change in symptoms with sitting/neck or trunk flexion/turning neck/when still (OR 2.642)
- Participants were asked if their upper or lower extremity symptoms changed for the better or worse with sitting, bending forwards with their cervical or lumbar spine, turning their neck or if they remained still in one position, while not moving their trunk or extremities
Change in symptoms with posture change (OR 3.956) – STRONGEST indicator
Restrictions in spinal movements (OR 2.633)
No restrictions in extremity movements (OR 2.241)

*The optimal number of indicators for classification was two (sensitivity = 0.638, specificity = 0.807).

Conclusion:

This study provides guidance on clinical indicators that help to predict the source of symptoms for isolated extremity pain. The clinical indicators will allow clinicians to supplement their decision-making process regarding spinal and extremity differentiation to appropriately target their examinations and interventions.

Implications for MDT clinician:

The author’s note this is one of the first studies to provide a combination of clinical indicators to predict a spinal source for isolated extremity pain. These clinical indicators need to be validated in subsequent studies. This provides good clinical utility, allowing clinicians to use these indicators to determine the likelihood of a spinal source for extremity pain.

The significant clinical indicators reported included a combination of factors from the patient’s history and the physical examination. This is very important for MDT clinicians who carry out this standardized history and physical examination daily in the clinic with patients so this can assist them with better pattern recognition to help with the diagnostic and management process. However, pattern recognition, although extremely important, has been shown to be more readily and appropriately used in clinicians with more experience while novice clinicians are left to use more hypothetical-deductive reasoning (Edwards et al 2004). Now clinicians, both novice and experienced, have some verification that these observations can be used in the decision-making for differentiation with more confidence. Identifying clinical variables and indicators like this is exceedingly important as well due to the well-known limitations of static diagnostic imaging studies which are riddled with both false positive and false negative findings (Brinjikji et al 2014, Nakashima et al 2015). Many times these diagnostic imaging findings may not have any bearing at all on the patients issue – i.e., a patient with isolated knee pain with possible MRI finding of meniscal tear but who ends up demonstrating 2 or more of the above clinical indicators combined with confirmatory signs of directional preference after repeated movement testing of the lumbar spine – in this patient the MRI findings of the knee are again not relevant and could be harmful and lead to improper diagnosis and treatment. Many patients also become fixated on these imaging findings which can lead to psychosocial distress, fear, increase chance of getting surgery and worse outcomes (Flynn et al 2011). So, some research now supporting more clinical indicators can be important to help educate and reassure patients fears of what may be irrelevant and/or asymptomatic diagnostic imaging findings.

Utilizing this information, a clinician can also be timelier in the spinal/extremity differentiation if most indicators are negative or, conversely, be more exhaustive if enough of the indicators are positive. This is also extremely important nowadays in the very competitive conservative orthopaedic field where many patients want quick results in addition to many times high copays or coinsurances limiting the number of times a clinician can see the patient. Also, the author’s discussed the findings from the original study (Rosedale et al 2019) showing higher prevalence of hip/thigh pain being of spinal source now combined with the clinical indicators above, meaning an even more thorough screening of these areas with a potential higher proportion of spinal involvement would be indicated. The strongest indicator was changes in symptoms with posture change. Participants that had changes in symptoms with posture change were 3.956 times more likely to be classified into the spinal source group than the extremity source group. So again, if any changes in symptoms with posture change occurred, this would lead the clinician to a more exhaustive spinal screening process.

Some limitations of study:

Results of the current study would need to undergo a validation study in another sample to confirm findings.
Original study by Rosedale et al 2019 done by MDT trained clinicians so may not be applicable to clinicians utilizing other treatment approaches. However, as noted by the authors, many clinicians should be able to easily incorporate some of these clinical indicators into everyday practice with little formal MDT training (especially the history related questions).
No formal reference standard utilized (no injections to confirm possible anatomical source of symptoms).
Heterogenous group of participants were used in the study which is less “controlled” but the findings are more clinically valid as matched what typical mix of patients are usually seen in outpatient physical therapy clinics.
Finally only the factors which were initially set down as potential indicators were analyzed so there may be other indicators from the assessment that are predictive but were not analyzed as part of this study per the authors.

References

Rastogi R, Rosedale R, Kidd J, et al (2022): Exploring indicators of extremity pain of spinal source as identified by Mechanical Diagnosis and Therapy (MDT): a secondary analysis of a prospective cohort study, Journal of Manual & Manipulative Therapy, DOI: 10.1080/10669817.2022.2030625
Rosedale R, Rastogi R, Kidd J, et al (2019) A study exploring the prevalence of extremity pain of spinal source (EXPOSS). J Man Manip Ther. 28(4):222–230.
Edwards I, Jones M, Carr J, et al (2004) Clinical Reasoning Strategies in Physical Therapy. PHYS THER. 2004; 84:312-330.
Brinjikji W, Luetmer P H, Comstock B, et al (2014) Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR 1-6.
Nakashima H, Yukawa Y, Suda K, et al (2015) Abnormal findings on magnetic resonance images of the cervical spines in 1211 asymptomatic subjects. Spine 40 (6): 392-398.
Flynn T, Smith B, Chou R (2011) Appropriate Use of Diagnostic Imaging in Low Back Pain: A Reminder That Unnecessary Imaging May Do as Much Harm as Good. Journal of Orthopedic and Sports Physical Therapy Volume 44, Issue 11, p. 838-846.

Extremities: Observational studies