Optimizing success with lumbar disc arthroplasty.
OBJECTIVE
This study aimed at determining the variables that may prove useful in predicting clinical outcomes following lumbar disc arthroplasty.


METHODS
Pre- and post-operative imaging assessments were obtained for 99 single-level lumbar disc arthroplasty patients from a prospective IDE study. The assessments and patient demographics were tested to identify variables that were significantly associated with clinical outcomes.


RESULTS
Clinical outcome data were available for 85 % of patients at the 5-year follow-up. Numerous assessments made from the pre-operative imaging were found to have statistically significant associations with clinical outcomes at 2 and 5 years. The most notable factors were related to the amount of degeneration at the index level, with patients achieving better outcome scores at 5 years if they have higher grades of degeneration preoperatively.


CONCLUSIONS
Several variables may prove effective at optimizing clinical outcomes including a preoperative disc height <8 mm, Modic type 2 changes adjacent to the target disc, a low amount of lordosis present at the treatment level, low levels of fatty replacement of the paraspinal musculature, a prominent amount of facet joint or disc degeneration, and the presence of flat or convex vertebral endplates. There were also post-operative findings associated with better patient outcomes including a larger percent of the endplate covered with the implant, larger implant heights, greater increases in disc space heights, and a larger increase in index level lumbar lordosis. These variables could be explored in other clinical studies to facilitate meta-analyses that could identify effective strategies to optimize clinical outcomes with lumbar disc arthroplasty.
The Orthopedic Center of St. Louis, St. Louis, MO, USA, mfgspine@gmail.com.
Matthew F
MF
Gornet
Francine
F
Schranck
Nicholas D
ND
Wharton
Douglas P
DP
Beall
Elizabeth
E
Jones
Mark E
ME
Myers
John A
JA
Hipp
D000293:Adolescent; D000328:Adult; D000368:Aged; D001175:Arthrography / Q000592:standards*; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016015:Logistic Models; D008141:Lordosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000592:standards*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012447:Sacrum / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D059145:Total Disc Replacement / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery