Premium
Reliability of zygapophysial (Z) joint measurements taken from MRIs of subjects with acute low back pain
Author(s) -
Cramer Gregory D.,
Cantu Joe A.,
Pocius Judith D.,
Balester Frank,
Simpson Derek R.J.,
Horner Tyra B.,
Healy Joshua,
McKinnis Ray A.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.649.7
Subject(s) - medicine , nuclear medicine , low back pain , limits of agreement , reliability (semiconductor) , back pain , physics , pathology , power (physics) , alternative medicine , quantum mechanics
The central anterior to posterior (A‐P) distance of the left and right L4/L5 and L5/S1 zygapophysial (Z) joint space is being measured from MRI scans to assess changes following spinal manipulation. This IRB approved study assesses the reliability of those measurements. An independent radiologist chose 6 subject scans. Three observers measured these scans (24 measurements, rounded to 0.1mm using a backlit digitizer) on two separate occasions separated by a minimum of 4 weeks. Observers were blinded to each other and their previous work. Intra‐ and interobserver reliability was calculated by means of intra‐class correlation coefficients (ICCs), and mean differences. ICCs showed intraobserver reliabilities of 0.95 (95%CI 0.87‐0.98), 0.83 (0.62‐0.92), and 0.92 (0.83‐0.96) for each of the 3 observers; and interobserver reliabilities of 0.90 (0.82‐0.95), 0.79 (0.61‐0.90), and 0.84 (0.75‐0.90) for the first and second measurements and overall reliability, respectively. The mean difference between the first and second measurements was ‐0.04 ( + 1.96 SD= ‐0.37 ‐ 0.29), 0.23 (‐0.48 ‐ 0.94), 0.25 (‐0.24 ‐ 0.75), and 0.15 (‐0.44 ‐ 0.74) for each of the 3 observers and the overall agreement, respectively. A mean difference of < + 0.4 was considered clinically acceptable. Consequently, the measurements were highly reliable. Support: NIH/NCCAM (Grant# 2R01 AT000123).