Effects of Cervical Extension on Deformation of Intervertebral Disk and Migration of Nucleus Pulposus
Kim, Yoon-Ho et al.
PM&R , Volume 9 , Issue 4 , 329 - 338
We theorized that active cervical extension should influence the position of the nucleus pulposus (NP) within the intervertebral disk (IVD) in the sagittal plane. Although several studies on the lumbar IVD have been conducted, there are no quantitative data for in vivo positional changes of the NP in the cervical IVD.
To evaluate the influence and mechanism of cervical extension on the deformation and migration of IVD and NP in the sagittal plane and understand underlying mechanisms of the extension maneuver.
Asymptomatic subjects underwent magnetic resonance imaging while supine with their cervical spines in neutral and extended positions.
Academic medical center.
Ten young, healthy male participants (age range 19-30 years; mean 22.4 ± 1.64 years).
T2-weighted sagittal images from C3-C4 to C6-C7 of subjects in both neutral and extension positions were analyzed.
Main Outcome Measurements
Deformation of IVD and positional change of NP were quantified and compared between neutral and extension positions. Intersegmental angles between vertebrae, horizontal positions of anterior and posterior IVD and NP margins, IVD outer and inner heights, and sagittal morphology of NP were quantified and compared between the neutral and extension positions. Correlations between the measured parameters and segmental extension angle were also investigated.
Anterior and posterior IVD margins moved posteriorly with respect to the vertebral body in extension. Both NP margins remained unchanged relative to the vertebral body but moved anteriorly with respect to the IVD. IVD outer and inner heights in the anterior region increased in extension, and morphological changes of the NP were less noticeable when compared with its relative migration within the IVD. Most of the intradiskal changes were linearly correlated with the segmental extension angle.
Cervical extension induces anterior migration of the NP away from the posterior disk margin and may have a clinical effect on diskogenic neck pain resulting from internal disk disruption.
Level of Evidence
JAMA. 2018 Mar 6;319(9):872-882. doi: 10.1001/jama.2018.0899.
Effect of Opioid vs Nonopioid Medications on Pain-Related Function in Patients With Chronic Back Pain or Hip or Knee Osteoarthritis Pain: The SPACE Randomized Clinical Trial
Krebs EE1,2, Gravely A1, Nugent S1, Jensen AC1, DeRonne B1, Goldsmith ES1,3, Kroenke K4,5,6, Bair MJ4,5,6, Noorbaloochi S1,2.Author information
IMPORTANCE: Limited evidence is available regarding long-term outcomes of opioids compared with nonopioid medications for chronic pain.
OBJECTIVE: To compare opioid vs nonopioid medications over 12 months on pain-related function, pain intensity, and adverse effects.
DESIGN, SETTING, AND PARTICIPANTS: Pragmatic, 12-month, randomized trial with masked outcome assessment. Patients were recruited from Veterans Affairs primary care clinics from June 2013 through December 2015; follow-up was completed December 2016. Eligible patients had moderate to severe chronic back pain or hip or knee osteoarthritis pain despite analgesic use. Of 265 patients enrolled, 25 withdrew prior to randomization and 240 were randomized.
INTERVENTIONS: Both interventions (opioid and nonopioid medication therapy) followed a treat-to-target strategy aiming for improved painand function. Each intervention had its own prescribing strategy that included multiple medication options in 3 steps. In the opioid group, the first step was immediate-release morphine, oxycodone, or hydrocodone/acetaminophen. For the nonopioid group, the first step was acetaminophen (paracetamol) or a nonsteroidal anti-inflammatory drug. Medications were changed, added, or adjusted within the assigned treatment group according to individual patient response.
MAIN OUTCOMES AND MEASURES: The primary outcome was pain-related function (Brief Pain Inventory [BPI] interference scale) over 12 months and the main secondary outcome was pain intensity (BPI severity scale). For both BPI scales (range, 0-10; higher scores = worse function or pain intensity), a 1-point improvement was clinically important. The primary adverse outcome was medication-related symptoms (patient-reported checklist; range, 0-19).
RESULTS: Among 240 randomized patients (mean age, 58.3 years; women, 32 [13.0%]), 234 (97.5%) completed the trial. Groups did not significantly differ on pain-related function over 12 months (overall P = .58); mean 12-month BPI interference was 3.4 for the opioid group and 3.3 for the nonopioid group (difference, 0.1 [95% CI, -0.5 to 0.7]). Pain intensity was significantly better in the nonopioid group over 12 months (overall P = .03); mean 12-month BPI severity was 4.0 for the opioid group and 3.5 for the nonopioid group (difference, 0.5 [95% CI, 0.0 to 1.0]). Adverse medication-related symptoms were significantly more common in the opioid group over 12 months (overall P = .03); mean medication-related symptoms at 12 months were 1.8 in the opioid group and 0.9 in the nonopioid group (difference, 0.9 [95% CI, 0.3 to 1.5]).
CONCLUSIONS AND RELEVANCE: Treatment with opioids was not superior to treatment with nonopioid medications for improving pain-related function over 12 months. Results do not support initiation of opioid therapy for moderate to severe chronic back pain or hip or knee osteoarthritis pain.
TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01583985.