ABSTRACT
Objectives
A prospective observational cohort study was conducted to (1) report the prevalence of Mechanical Diagnosis and Therapy (MDT) classifications, Centralization (CEN), and Non-CEN among patients with Cervical Spine Radiculopathy (CSR), and (2) describe the association between classification via CEN and Non-CEN and clinical outcomes at follow-up.
Methods
Data were collected from 680 consecutive patients who presented to outpatient, orthopedic physical therapy clinics with primary complaints of neck pain with and without radiculopathy; thirty-nine patients (6%) met the physical examination inclusion criteria for CSR. First examination and follow-up data were completed by 19 patients.
Results
Seventy-nine percent of patients’ conditions were classified as Reducible Derangement at first examination and 21% were classified as either Irreducible Derangement, Entrapment, or Mechanically Inconclusive. The prevalence of CEN and Non-CEN was 36.8% and 47.4%, respectively. All patients treated via MDT methods made clinically significant improvements in disability, but not pain intensity, at follow-up. The magnitude of change in clinical outcomes was greatest for patients who exhibited CEN; however, the changes in disability and pain intensity at follow-up were not statistically significant compared to patients who exhibited Non-CEN at first examination. Patients who exhibited CEN were discharged, on average, ten days earlier and had one less treatment visit compared to patients who exhibited Non-CEN.
Discussion
The findings of this study show that patients with CSR can be classified and treated via MDT methods and experienced clinically significant improvements in disability, but not pain intensity, at follow-up. Providers should consider MDT classification and treatment to improve clinical outcomes for their patients affected by CSR.
KEYWORDS: Cervical spine, cervical radiculopathy, neck pain, directional preference, centralization, McKenzie, orthopedic, musculoskeletal
Introduction
Neck pain disorders with and without radiculopathy are regarded as clinically distinct entities [1–4]. Neck pain with radiculopathy, or CSR, involves compression of the cervical nerve root [5] as a result of disc herniation or bony osteophyte impingement [5,6]. The clinical manifestations of nerve root compression distinguish CSR from neck pain without radiculopathy and include radiating pain into the arm in combination with motor, reflex, and/or sensory changes [6]. CSR is a common reason patients seek medical care [7,8] and the annual incidence is 107.3 per 100,000 for men and 63.5 per 100,000 for women [9]. Many cases do not resolve and result in chronic symptoms. CSR leads to lasting paresis and paresthesia at one-year follow-up in as many as 50% of those affected [10,11]. A study by Thoomes et al. [12] on the natural course of CSR showed that 56% of patients continue to exhibit symptoms at 19-year follow-up. Furthermore, as high as 67% of patients’ symptoms exhibit progressive deterioration over time [13]. It is not uncommon in the authors’ clinical experiences that patients with CSR are more likely to consider invasive and costly procedures such as surgery compared to patients with neck pain without radiculopathy. In a prospective study examining patients with CSR who were referred to board-certified neurosurgeons or orthopedic surgeons [10], 38% of patients received surgical interventions including neural foraminotomy, cervical discectomy, and/or spinal fusion. Due to the substantial burdens related to CSR and neck pain without radiculopathy, the Patient-Centered Outcomes Research Institute (PCORI) has prioritized the need for further research to examine the classification of both condition types [14]; previous research has suggested that classifying patients with cervical spine disorders via subgroups based on clinical characteristics and matching these subgroups to management strategies could improve patient outcomes [3,15,16]. The authors of the present study sought to contribute to PCORI’s agenda by examining patients with CSR only. PCORI has also prioritized a need for exploring the classification of neck pain with and without radiculopathy, the effectiveness and safety of nonsurgical options, the effectiveness of assessment instruments, and predictors of chronic pain, opioid dependence, or other undesirable outcomes. The examination of CEN and Non-CEN as a classification criterion has been made a top priority in the PCORI agenda as it relates to its effect on patient-centered outcomes.
The clinical diagnosis of CSR is established via a thorough history and physical examination while considering radiating symptoms into the extremity and subsequent motor and/or sensory impairments [4]. Several clinical examination findings have been reported to assist identification of CSR including tests which reproduce or relieve radiating symptoms with cervical spine compression, distraction, and/or upper-limb nerve mobility. For individual tests, the Spurling’s Test and the Distraction Test have been recommended for clinical use and have good specificity and positive likelihood ratio values [4,17]. A negative upper limb tension test may help rule out the presence of CSR and has a high sensitivity (Sp = 0.97) and small likelihood ratio value (LR- = 0.12) [17]. Composite tests tend to exhibit better diagnostic accuracy compared to individual tests for identifying CSR [17,18]. A test-item cluster (Appendix) was proposed by Wainner et al. [17] that produced larger post-test probability changes for the diagnosis of CSR than any single clinical examination finding. Three positive tests exhibited specificity, likelihood ratio, and post-test probability values of 0.94, 6.1, and 65%, respectively. The specificity, likelihood ratio, and post-test probability values for four out of four positive tests increased to 0.99, 30.3, and 90%, respectively. Indeed, individual tests such as the Spurling’s Test and Distraction Test exhibit acceptable diagnostic accuracy for use in clinical practice, and diagnostic accuracy is improved when clinicians cluster patient-reported signs and symptoms and employ a series of CSR tests.
Non-specific classification systems are used in conjunction with the aforementioned clinical tests [4]. MDT is a treatment-based classification system that identifies non-pathology specific subgroups through a detailed history and physical examination process consisting of repeated and sustained end-range movements [16]. The patient’s symptomatic and mechanical (i.e. range of movement and strength-related changes) responses to these movement strategies establish classification (Appendix) and the subsequent management approach. CEN is a hallmark classification criterion in the MDT system and has been extensively studied in patients with lumbar spine disorders [19,20]. CEN is characterized by spinal pain and referred spinal symptoms that are progressively abolished in a distal-to-proximal direction in response to repeated and/or sustained end-range movement [16]. The presence of CEN is generally associated with a favorable outcome and has been shown to be a useful indicator of prognosis and guide for management strategies [19,21]. Non-CEN, or the absence of CEN, is characterized by symptoms that do not move proximally toward the midline of the spine, do not change, or that move distally away from the spine during the physical examination [16]. Non-CEN has been generally associated with apoorer prognosis and inferior clinical outcomes [22–28]. The interrater reliability for the use of an overlay template to identify the presence of CEN and Non-CEN has been reported to be almost perfect agreement (k = 0.96–1.00) [29].
Although the MDT classification system does not rely on pathoanatomic causes to diagnose and treat patients, several studies have linked CEN to discogenic problems by comparing discography to symptomatic findings in the lumbar spine [30–34]. A significant association between positive discography and the occurrence of CEN and Non-CEN has been established [30]. Considering that posterior disc encroachment has been purported to be a cause of radiculopathy [1] and that the morphology of the cervical disc is to some degree similar to the lumbar disc [35], a study by Kim et al. [36] showed that cervical spine extension procedures produced anterior migration of the nucleus pulposus away from the posterior disc margin. The authors concluded that cervical extension movements may produce favorable clinical effects as it relates to radiculopathy. Spinal extension movements are the most common procedures associated with CEN [19] and have been shown to improve radicular signs and symptoms [37–40]. A study by Abdulwahab et al. [37] showed that repeated neck retractions, a commonly employed MDT procedure consisting of mid and lower cervical spine extension movement, was effective at decompressing cervical neural elements and reducing cervical radicular pain in patients with CSR. Spanos et al. [38] described a patient with cervical radiculopathy with disc herniation who responded to MDT-based procedures and subsequently became symptom-free, and the corresponding MRI findings revealed a 56% reduction in the size of the disc herniation. A case report by Schenk et al. showed rapid and sustained improvement with extension-based MDT procedures, deep neck flexor muscle strengthening, and neuromobilization for a patient diagnosed with CSR [39]. In another case report, a patient who presented with radiculopathy and signs of myelopathy improved rapidly with end-range cervical spine extension movements that induced CEN [40]. However, no prospective studies have assessed the association between MDT classification and clinical outcomes for patients with CSR.
Based on the lack of prospective studies examining MDT classification and outcomes for patients with CSR and the call for more studies in this regard [14], the primary aims of this study were to (1) report the prevalence of MDT classifications, CEN, and Non-CEN among patients with CSR, and (2) describe the association between classification via CEN and Non-CEN and clinical outcomes. Since previous reports related to MDT classification suggest that the Derangement classification is the most common classification [19], CEN is less prevalent than Non-CEN at first examination [24,41], and CEN generally results in more favorable clinical outcomes [19], the hypotheses of this investigation were that (1) the prevalence would be highest for the Reducible Derangement classification at first examination, (2) fewer patients would exhibit CEN at first examination than Non-CEN, and (3) patients who exhibited CEN would demonstrate clinically significant differences in disability and pain intensity at follow-up relative to patients who exhibited Non-CEN in patients with CSR.
Methodology
Design
A prospective observational cohort study was conducted. Data were analyzed from 680 consecutive patients who presented to outpatient, orthopedic physical therapy clinics with primary complaints of neck pain with and without radiculopathy (Figure 1). Data were collected from 2014 through 2015 in Oklahoma, Florida, South Carolina, and Alabama in four outpatient orthopedic physical therapy clinics. One chiropractor and nine physical therapists participated in the study (average years of clinical experience: 13.5; average age: 39 years (27–64); 70% males). All providers attained at least a bachelor’s degree. Four physical therapists held a Doctorate in Physical Therapy (DPT). Six providers were certified in MDT (Cert. MDT) and four held diplomas in MDT (Dip. MDT). One provider was a Board Certified Orthopedic Clinical Specialists (OCS). The Florida State University Institutional Review Board for Protection of Human Subjects and the Florida Agricultural and Mechanical University Institutional Review Board for Protection of Human Subjects approved the project. Patient informed consent was not required for the analysis and reporting of data as this study did not include any change in routine clinical practice.
Figure 1.
Flow of patients.
Patients were included in the analysis if they (1) presented with complaints of neck pain with symptoms that radiated into the upper extremity, (2) had sensory, motor, and/or reflex changes in the upper extremity including paresthesias or numbness, and (3) had a positive finding for any of the following tests at first examination: (i) Spurling’s Test, (ii) Distraction Test, and/or (iii) at least three out of four positive tests for identifying the presence of cervical radiculopathy proposed by Wainner et al. [17]. Patients were excluded from the study if they had cervical spine surgery within the preceding twelve months.
Classification and physical examination procedures
Patients were assessed and treated via MDT methods. A standard MDT evaluation was conducted consisting of repeated and sustained end-range movements while monitoring patients’ symptomatic and mechanical responses [16]. CEN and Non-CEN were recorded at the first examination by using a body diagram and overlay template [29]. The patient was instructed to shade in the body regions on the diagram where he or she was experiencing symptoms at the moment. If the patient was not experiencing any resting symptoms, the patient’s condition was labeled as Non-Classifiable (NC). The managing provider asked the patient to complete the body diagram immediately before and after movement testing during the MDT examination. Post evaluation, providers documented the presence or absence of CEN as well as the MDT classification (Appendix).
A series of physical examination tests were performed at the first examination in conjunction with a standard MDT evaluation to assist identification of patients with CSR. A test-item cluster proposed by Wainner et al. [17] was implemented including Spurling’s Test [42], the Distraction Test [17], the Upper Limb Tension Test (ULTT) [43], and assessment of cervical spine rotation range of motion (Appendix) [17,44]. A standard neurological examination was conducted including testing of upper extremity myotomes, dermatomes, and reflexes (Appendix) [45,46].
Provider training
Providers in the study had extensive training in orthopedic physical examination and manual therapy techniques. Providers routinely performed physical examination tests such as ULTTs, myotome and dermatome assessments, and joint range of motion assessments via goniometer measurement. Prior to the start of the study, training and practice sessions were conducted on how to perform the Spurling’s Test and the Distraction Test; all providers had previous experience performing these tests. Providers in the study were advised to use scripted introductions and standardized procedures when administering physical examination tests and self-report questionnaires. Participating providers and supporting administrative personnel received three, one-hour training sessions regarding data collection and management practices. A standard operating procedure was developed by our research network that provided detailed study procedures, operational definitions of the constructs being measured, and sample case study vignettes.
Data collection
Providers collected patient-reported and clinical examination responses at first examination, regularly throughout the care episode, and at discharge. The managing providers were responsible for determining and reporting inclusion, exclusion, and discharge status. Pain intensity reported by the patient within ‘the last few days’ was assessed using an 11-point Numeric Pain Rating Scale (NPRS) ranging from 0 (‘No pain’) to 10 (‘Worst Pain Imaginable’). The NPRS has been shown to be reliable and valid [47,48] with a minimal detectable improvement of 4.1 points in patients with CSR [48]. The Neck Disability Index (NDI) is a patient self-report disability questionnaire for neck pain with and without radiculopathy. The score ranges from 0 to 50 with higher scores indicating higher levels of disability. Stratford et al. reported a minimally important change in the NDI score of 5 points (out of 50) [49]. The NDI has been shown to be an acceptable clinical measure for patients with cervical spine disorders [49–51].
Data analysis
Descriptive statistics were generated including proportions, standard deviations, and ranges for patient characteristics collected at first examination. Chi-square tests of independence (dichotomous and categorical data) or two-sample t-tests (continuous data) were performed to compare patient characteristics and determine equivalence between patients with first examination data only and patients with first examination and follow-up data. Constructs measured approximated a normal distribution and the significance level for all tests was set at p < .05. A summary table was created for the prevalence of positive neurological test cluster items (i.e. Spurling’s Test, the Distraction Test, the ULTT, and a cervical spine rotation range of motion measurement of less than 60 degrees), myotome deficits, and dermatome deficits for CEN and Non-CEN groups (Table 2). In order to address the first objective of determining classification prevalence, we categorized the prevalence at first examination at two levels: (1) the prevalence of MDT classifications and (2) the prevalence of CEN and Non-CEN. Two-sample t-tests considering a normal distribution were used to address the second objective of determining the association between classification via CEN and Non-CEN at first examination and clinical outcomes (i.e. disability and pain intensity) at follow-up. Difference scores, or the difference between the clinical outcome measure (i.e. disability or pain intensity) at first examination and follow-up were calculated and these data were compared to the NPRS minimal detectable improvement value for pain and the NDI minimal clinically important difference value for disability. The average visits and duration of care were calculated for patients with first examination and follow-up data and adjusted by CEN and Non-CEN at first examination.
Table 2.
Neurological findings of patients with first examination and follow-up data (n = 19).
| Neurological Finding | CEN | Non-CEN |
|---|---|---|
| 3 out of 4 | 15.8% | 5.3% |
| 4 out of 4 | 5.2% | 0.0% |
| (+) Spurling’s Test | 5.2% | 100.0% |
| (+) Distraction Test | 10.5% | 5.3% |
| (+) ULTT | 31.6% | 31.6% |
| (+) CS Rot <60 Degrees | 18.6% | 5.3% |
| Myotome Deficits | 15.8% | 5.3% |
| Dermatome Deficits | 0.0% | 0.0% |
| Altered Reflexes | 0.0% | 0.0% |
Notes: CEN = Centralization; Non-CEN = Non-Centralization; ULTT = Upper Limb Tension Test; CS Rot <60 Degrees = Cervical Spine Rotation less than 60 degrees; Myotome Deficits were considered present according to manual muscle testing during the physical examination; Dermatome Deficits were considered present according to light touch testing during the physical examination; Altered Reflexes included assessment of Biceps Brachii, Brachioradialis, and Triceps reflexes; 3 out of 4 = three out of four positive tests were present (i.e. Spurling’s Test, Distraction Test, ULTT, or CS Rot < 60 degrees); 4 out of 4 = four out of four positive tests were present (i.e. Spurling’s Test, Distraction Test, ULTT, or CS Rot < 60 degrees)
Results
Six hundred and eighty consecutive patients entered the clinic during the study period (Figure 1). Forty-four patients did not complete first examination data collection resulting in a participation rate of 94%, and 39 patients (6%) met the physical examination inclusion criteria for the study. Nineteen patients completed first examination and follow-up data collection (49% completion rate). The characteristics of the study participants are displayed in Table 1 and reasons for not commencing data collection can be found in Figure 1. Patients with first examination data only did not significantly differ relative to age, gender, symptom acuity, surgical history, NDI score at first examination, and pain intensity score at first examination compared to patients with first examination and follow-up data; however, patients with first examination data only took less medication for their conditions (p-value = 0.04) than patients with first examination and follow-up data.
Table 1.
Patient characteristics.
| Characteristics | First Examination Only (n = 20) | First Examination and Follow-up Data (n = 19) |
|---|---|---|
| Age (y) | 51.04 ± 15.4 (35–74) | 50.5 ± 15.1 (34–78) |
| Missing | 1.40% | 0.00% |
| Gender | ||
| Male | 50.00% | 36.80% |
| Female | 50.00% | 63.20% |
| Missing | 0.00% | 0.00% |
| Symptom Acuity | ||
| Acute (0–2 weeks) | 70.00% | 63.20% |
| Sub-Acute (3–11 weeks) | 5.00% | 5.20% |
| Chronic (≥12 weeks) | 25.00% | 31.60% |
| Missing | 0.00% | 0.30% |
| Surgical History | ||
| None | 75.00% | 94.70% |
| 1 or More | 10.00% | 5.30% |
| Missing | 15.00% | 0.80% |
| Medication for Condition | ||
| None | 30.00% | 15.80% |
| 1 or More | 70.00% | 84.20% |
| Missing | 0.00% | 0.00% |
| Imaging | ||
| None | 50.00% | 57.90% |
| 1 | 35.00% | 13.60% |
| 2 or More | 15.00% | 28.50% |
| Missing | 0.00% | 0.00% |
| Exercise History | ||
| 1 or 2 Times per Week | 25.00% | 26.30% |
| At least 3 Times per Week | 30.00% | 47.40% |
| Seldom or Not at All | 35.00% | 26.30% |
| Missing | 10.00% | 0.00% |
| Referral Type | ||
| Primary Care | 35.00% | 63.20% |
| Specialist | 10.00% | 10.50% |
| Self | 10.00% | 0.00% |
| Other | 40.00% | 26.30% |
| Missing | 10.00% | 0.00% |
| Number of Comorbid Conditions | ||
| None | 20.00% | 15.80% |
| 1 | 26.20% | 31.60% |
| 2 or 3 | 50.00% | 36.80% |
| 4 or more | 20.00% | 15.80% |
| Missing | 10.00% | 0.00% |
| Payer | ||
| Auto | 0.00% | 0.00% |
| Health Maintenance Organization (HMO) | 90.00% | 57.90% |
| Medicaid | 0.00% | 0.00% |
| Medicare Part B | 0.00% | 0.00% |
| Patient Private Pay | 0.00% | 0.00% |
| Preferred Provider Organization (PPO) | 10.00% | 36.80% |
| Workers’ Compensation | 0.00% | 0.00% |
| Other | 0.00% | 5.30% |
| Missing | 0.00% | 0.00% |
| Intake NDI | 14.1 ± 7.5 (9–29) | 14.2 ± 7.4 (4–31) |
| Missing | 0.00% | 0.00% |
| Pain Intensity First Examination | 5.0 ± 2.3 (1–10) | 5.4 ± 2.4 (1–10) |
| Missing | 0.00% | 0.00% |
Neurological physical examination tests were recorded at first examination and analyzed for patients with first examination and follow-up data. For the test-item cluster, 21% of patients exhibited 3 out of 4 criteria and 11% exhibited 4 out of 4 criteria. For single-item tests, 90% of patients exhibited a positive Spurling’s Test, 37% exhibited a positive Distraction Test, 74% exhibited a positive ULTT, and 26% exhibited a cervical spine rotation range of motion measurement less than 60 degrees. In addition, 15.8% of patients exhibited myotome deficits via manual muscle test assessment and 5.0% of patients exhibited dermatome deficits via light touch assessment. A breakdown of neurological test findings categorized by CEN and Non-CEN can be found in Table 2.
The prevalence of MDT classifications (95% CI) among patients with CSR were analyzed. Seventy-nine percent of patients’ conditions were classified as Reducible Derangement (0.61, 0.97). Twenty-one percent of patients’ conditions were classified as either Irreducible Derangement, Entrapment, or Mechanically Inconclusive (0.03, 0.39). The prevalence of CEN and Non-CEN at first examination was 36.8 and 47.4 percent, respectively. Patients who had no resting pain at the physical examination and were not able to be classified via CEN and Non-CEN criteria [29] accounted for 5.3% of the sample, and 10.5% of CEN data were missing. The association between CEN and Non-CEN and clinical outcomes (i.e. disability and pain intensity) at follow-up were analyzed. Both CEN and Non-CEN categories treated via MDT methods made improvements at follow-up and the magnitude of improvement was greater for those that exhibited CEN (the CEN group had 5.8 and 1.24 points greater change in disability and pain intensity scores than the Non-CEN group, respectively). Clinically significant improvements in disability, but not pain intensity, were observed for both categories at follow-up (Table 3); however, the changes in disability and pain intensity at follow-up for the CEN group did not exhibit a statistically significant difference compared to the Non-CEN group (NDI p-value = 0.24; NPRS p-value = 0.47). The average time to discharge and treatment visits for patients’ conditions which exhibited CEN at first examination was 23.5 days (SD = 9.7; Range = 14–30) and 4.0 visits (SD = 2.2; Range = 1–8). For patients’ conditions which exhibited Non-CEN at first examination, the average time to discharge and treatment visits were 33.3 days (SD = 16.9; Range = 9–56) and 5.0 visits (SD = 1.3; Range = 3–6).
Table 3.
Follow-up disability and pain intensity comparison (n = 19).
| CEN | Non-CEN | |
|---|---|---|
| Mean NDI at First Examination | 17.85 | 22.56 |
| Mean NDI at Follow-Up | 3.71 | 14.22 |
| Mean Difference | 14.14 | 8.34 |
| Mean NPRS at First Examination | 5.29 | 7.22 |
| Mean NPRS at Follow-Up | 1.71 | 4.88 |
| Mean Difference | 3.58 | 2.34 |
| . | ||
Notes: NDI = Neck Disability Index; NPRS = Numeric Pain Rating Scale; CEN = Centralization; Non-CEN = Non-Centralization; p-value NDI Difference Score = 0.24; p-value NPRS Difference score = 0.47; 10.5% of CEN data were missing
The Mean Difference was calculated by subtracting the mean change in the first examination outcome measure (i.e. the NDI or NPRS) from the mean change in the follow-up measure (first examination mean change minus follow-up mean change = Mean Difference)
Discussion
The findings of this study show that (1) patients with CSR can be classified and treated via MDT methods, (2) patients that were classified and treated via MDT methods experienced clinically significant improvements in disability, but not pain intensity, at follow-up, and (3) the CEN group exhibited a larger magnitude of improvement in disability and pain intensity and had less treatment visits and a shorter duration of care compared to the Non-CEN group, although the differences in outcomes were not statistically significant. These results contribute to the PCORI agenda [14], providers, and researchers by demonstrating ability to classify patients with CSR, showing the effectiveness of MDT classification and treatment, and forming a basis for further classification studies in this cohort.
This investigation is the first multi-center prospective study to exclusively assess the prevalence of CEN in consecutive patients with CSR. Previous reports investigating the prevalence of CEN include samples of patients either with neck pain only or with neck pain with and without radiculopathy. In a systematic review that analyzed the prevalence of CEN [19], 62 out of 168 (36.9%) patients with cervical spine disorders exhibited CEN. In a more recent prospective study, the prevalence of CEN was found to be 40% in patients with neck pain [24]. The prevalence findings related to CEN (36.8%) in the current investigation provides support for and aligns with earlier studies which reported data on patients classified at the first examination. However, further studies should consider serial assessments of CEN over time [52,53]. A more recent study by Otero et al. [52] showed the importance of assessing the prevalence of CEN across multiple visits. The study evaluated the prevalence of CEN throughout five visits in patients with non-specific neck pain in which CEN increased from 52.9% at the first visit to 76.03% by the fifth visit. These data express how the prevalence of CEN may change upon reassessment as patients undergo treatment and also reinforces a previous report [53] that indicated that multiple-visit classification improved the precision for discriminating differences in pain and disability. Our data collection process prohibited analysis of serial assessments of CEN, and further studies need to be conducted to assess if and how the prevalence of CEN at follow-up assessment changes in patients with CSR.
Patients’ conditions which exhibited CEN (36.8%) and Non-CEN (47.4%) at first examination that were assessed and treated via MDT methods demonstrated clinically significant changes in disability, but not pain intensity, at follow-up. These findings verify the results of a similar study by Edmonds et al. [24] which assessed patients with neck pain and found that CEN-based categories were not predictive of pain intensity outcomes. The minimal detectable improvement value used as a reference criterion in the study by Edmonds et al. is the same as that used in the current investigation (4.1 NPRS points). The groups in the current investigation exhibited greater than a two-point NPRS change (CEN pain intensity change = 3.58; Non-CEN pain intensity change = 2.34), which would have been considered clinically significant if referenced to the established low back pain criteria [54] of two-points of change on the NPRS. An NPRS change of 4.1 is more than double this criteria for the necessary magnitude of change to be deemed clinically significant. Further investigation of the minimal improvement needed to be considered clinically significant for patients neck pain with and without radiculopathy may be warranted.
Patients’ conditions which exhibited CEN at first examination achieved greater magnitudes of change in both disability and pain intensity (patients who exhibited CEN had 5.8 and 1.24 points greater change than patients who exhibited Non-CEN for disability and pain intensity scores, respectively), however, no significant differences were found between the groups for disability (p-value = 0.24) or pain intensity (p-value = 0.47) outcomes at follow-up. The lack of differences in outcomes may be attributed to when the outcomes were collected. Clinical outcomes were assessed at two time points, first examination and follow-up (average follow-up time for CEN and Non-CEN groups was 23.5 and 33.3 days, respectively). Therefore, it was not possible to determine if each group exhibited differences at other time points. CEN is characterized by rapid improvements in symptoms and function [16] and further studies may expose clinically significant differences compared to those that exhibit Non-CEN during the first week of treatment. Furthermore, the interventions in this study were not recorded, thus it was not possible to determine if the lack of difference in the outcomes was due to the treatments performed, the prognostic attributes of the system, or both. Studies which examine patient classification, treatments performed, and the associated outcomes obtained are needed.
There are several limitations to consider in the present study. Although formal feedback was not collected from the providers in the study, a significant level of burden was reported in administering the clinical tests proposed by Wainner et al. [17] in addition to a standard MDT examination. Further studies should investigate the level of burden and feasibility of including this test-item cluster as a part of a standard MDT evaluation. Only 6% of patients met the inclusion criteria for having CSR compared to all patients presenting to the clinics with cervical spine disorders and may be related to referral patterns for physical therapy services. The practice settings were diverse and represented typical orthopedic physical therapy clinics (i.e. four outpatient orthopedic physical therapy clinics across four US states). Primary care and specialist physicians comprised 74% of the sample referral base; however, it could not be determined how these sources considered referral for physical therapy services, and, perhaps, patients with CSR were more likely to be escalated to services other than physical therapy based on the characteristics of the patient and provider. More studies are needed to examine the utility and generalizability of this test-item cluster across multiple health care settings and provider types.
Providers in the study were instructed to collect clinical outcome measures regularly throughout the care episode and at discharge to maximize completion rate (i.e. the percentage of patients in the sample who had both first examination and follow-up data). Despite these requirements, the completion rate was 18% lower than anticipated (expected = ≥60%; actual = 49%) which increases the susceptibility of selection bias. Attempts were made to reschedule patients who missed visits and did not return for follow-up contrary to advisement of the providers. Per facility standards, the providers were required to make at least two follow-up phone calls to reschedule the patient. Many patients may not have returned to physical therapy due to several factors including high co-pays and geographical location [55].
Conclusion
The findings of this study show that patients with CSR made clinically significant improvements when classified and treated via MDT methods and the CEN group exhibited greater improvement in clinical outcomes and a shorter duration of care compared to the Non-CEN group; however, the differences in outcomes were not statistically significant. Providers should consider MDT classification and treatment to improve clinical outcomes for their patients affected by CSR. Recommendations for researchers have been made to further study MDT classification and outcomes for patients with CSR.
Biographies
Richard Yarznbowicz obtained his doctor of physical therapy from the University of the Sciences in Philadelphia in 2010 before earning his diploma in Mechanical Diagnosis and Therapy in 2013. He is also a board certified Orthopedic Clinical Specialist. He has authored and co-authored several publications regarding the assessment and treatment of patients with musculoskeletal disorders.
Matt Wlodarski obtained his doctor of physical therapy from Northwestern University and a certification in Mechanical Diagnosis and Therapy in 2013. He enjoys treating patients in an outpatient setting and also programs healthcare technologies and data collection instruments to improve patient care. He has co-authored publications regarding Mechanical Diagnosis and Therapy on patients affected by spinal disorders.
Jonathan Dolutan obtained his Master of Science in Rehabilitation Science-Physical Therapy in 2004 and his Doctorate in 2008 from the Medical University of South Carolina. He was awarded his Diploma in Mechanical Diagnosis and Therapy in 2011. Jonathan has special interest in research data collection related to physical therapy intervention and injury prevention.
Appendix.
| MDT Classification | ||
|---|---|---|
| Classification [16] | Criteria | |
| Reducible Derangement |
|
|
| Dysfunction |
|
|
| Posture |
|
|
| Other |
|
|
| Test Cluster | ||
| CSR Examination Tests |
Description |
Positive Test Finding |
| Spurling’s Test | In a seated position, the patient’s cervical spine is laterally flexed toward the symptomatic side and overpressure (approximately 7 kg of force) is applied to the patient’s head [42] | Reproduction of the patient’s concordant sign is provoked |
| The Distraction Test | In the supine position, the patient’s cervical spine is flexed to a position of comfort and a distraction force (approximately 14 kg of force) is applied through the posterior occiput and chin [17] | Reduction or elimination of the patient’s concordant sign |
| ULTT | In the supine position, the provider sequentially introduces the following movements in the symptomatic upper extremity: (1) scapular depression, (2) shoulder abduction, (3) forearm supination, (4) wrist and finger extension, (5) shoulder external rotation, (6) elbow extension, and then (7) contralateral followed by ipsilateral cervical spine lateral flexion [43] | The test is considered positive if any one of the following is present: (1) the patient’s concordant sign is reproduced, (2) a side-to-side difference (>10 degrees) in elbow extension is present, (3) contralateral cervical spine lateral flexion increases symptoms, or (4) ipsilateral cervical spine lateral flexion decreases symptoms |
| CS Rotation ROM <60 Degrees |
In a seated position, the patient is asked to maximally rotate their neck, keeping shoulder movement to a minimum. Cervical spine rotation ROM to the involved side is measured using a standard long-arm goniometer [17,44] |
The test is considered positive if patients’ cervical spine rotation ROM to the involved side is less than 60 degrees |
| Standard Neurological Examination | ||
| Tests |
Description |
|
| Myotome Testing | Assessment of upper extremity myotomes via manual muscle testing includes the following: C5 – Elbow flexors (Biceps, Brachialis), C6 – Wrist extensors (Extensor Carpi Radialis Longus and Brevis), C7 – Elbow extensors (Triceps), C8 – Finger flexors (Flexor Digitorum Profundus) to the middle finger, and T1 – Small finger abductors (Abductor Digiti Minimi) [45] | |
| Dermatome Testing | Assessment of upper extremity dermatomes via light touch testing includes the following: C2 – At least 1 cm lateral to the occipital protuberance (alternatively 3 cm behind the ear), C3 – Supraclavicular Fossa (posterior to the Clavicle) and at the midclavicular line, C4 – Over the Acromioclavicular Joint, C5 – Lateral (radial) side of the Antecubital Fossa (just proximal to elbow crease), C6 – Thumb, dorsal surface, Proximal Phalanx, C7 – Middle finger, dorsal surface, Proximal Phalanx, C8 – Little finger, dorsal surface, Proximal Phalanx, and T1 – Medial (ulnar) side of the Antecubital Fossa, just proximal to the Medial Epicondyle of the Humerus [45] | |
| Reflex Testing | Assessment of muscle stretch reflexes via a standard reflex hammer includes the following: Biceps (C5–C6), Brachioradialis (C5–C6), and Triceps (C7). Reflex testing is graded via 0 = no response (always abnormal), 1+ = a slight but definitely present response (may or may not be normal), 2+ = a brisk response (normal), 3+ = a very brisk response (may or may not be normal), and 4+ = a tap elicits a repeating reflex or clonus (always abnormal) [46] | |
Notes: MDT = Mechanical Diagnosis and Therapy; CSR = Cervical Spine Radiculopathy; ULTT = Upper Limb Tension Test; CS = Cervical Spine; ROM = Range of Motion;
Disclosure statement
No potential conflict of interest was reported by the authors.
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