Spine patient outcomes research trial: radiographic predictors of clinical outcomes after operative or nonoperative treatment of degenerative spondylolisthesis.
METHODS
Subgroup analyses according to treatment received.


OBJECTIVE
To evaluate whether baseline radiographic findings predicted outcomes in patients with degenerative spondylolisthesis.


BACKGROUND
The spine patient outcomes research trial combined randomized and observational DS cohorts.


METHODS
The Meyerding listhesis grade was determined on the neutral radiograph (n = 222). Patients were classified as having low disc height if disc height was less than 5 mm. Flexion-extension radiographs (n = 185) were evaluated for mobility. Those with greater than 10 degrees rotation or 4 mm translation were considered hypermobile. Changes in outcome measures were compared between listhesis (grade 1 vs. grade 2), disc height (low vs. normal), and mobility (stable vs. hypermobile) groups using longitudinal regression models adjusted for potential confounders. Outcome measures included SF-36 bodily pain and physical function scales, oswestry disability index (ODI), stenosis bothersomeness index, and low back pain bothersomeness scale.


RESULTS
Overall, 86% had a grade 1 listhesis, 78% had normal disc height, and 73% were stable. Baseline symptom severity was similar between groups. Overall, surgery patients improved more than patients treated nonoperatively. At 1 year, outcomes were similar in surgery patients across listhesis, disc height, and mobility groups (ODI: grade 1 -23.7 vs. grade 2 -23.3, P = 0.90; normal disc height -23.5 vs. low disc height -21.9, P = 0.66; stable -21.6 vs. hypermobile -25.2, P = 0.30). Among those treated nonoperatively, grade 1 patients improved more than grade 2 patients (bodily pain + 13.1 vs. -4.9, P = 0.019; ODI -8.0 vs. + 4.8, P = 0.010 at 1 year), and hypermobile patients improved more than stable patients (ODI -15.2 vs. -6.6, P = 0.041; stenosis bothersomeness index -7.8 vs. -2.7, P = 0.002 at 1 year).


CONCLUSIONS
Regardless of listhesis grade, disc height or mobility, patients who had surgery improved more than those treated nonoperatively. These differences were due, in part, to differences in nonoperative outcomes, which were better in patients classified as grade 1 or hypermobile.
Pearson
Adam M
AM
Dartmouth Medical School, Lebanon, NH, USA. adam.m.pearson@dartmouth.edu
Lurie
Jon D
JD
Blood
Emily A
EA
Frymoyer
John W
JW
Braeutigam
Heike
H
An
Howard
H
Girardi
Federico P
FP
Weinstein
James N
JN
D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods / Q000639:trends*; D011237:Predictive Value of Tests; D011859:Radiography; D013168:Spondylolisthesis / Q000000981:diagnostic imaging* / Q000601:surgery / Q000628:therapy*; D016896:Treatment Outcome