One-Level Lumbar Arthroplasty: Is There a Difference in Clinical Outcome (Age)?

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The Spine Journal
Volume 6, Issue 5, Supplement 1, September-October 2006, Page 78S
Proceedings of the North American Spine Society 21st Annual Meeting

One-Level Lumbar Arthroplasty in Patients 18–45 Years of Age versus Patients 46–60 Years of Age: Is There a Difference in Clinical Outcome?

Richard Guyer MD1, Scott L. Blumenthal MD1, Fred H. Geisler MD, PhD2 and Paul C. McAfee MD3

1Texas Back Institute, Plano, TX, USA
2Illinois Neuro-Spine Center, Aurora, IL, USA
3St. Joseph Hospital, Towson, MD, USA

BACKGROUND CONTEXT: Lumbar arthroplasty with the Charité Artificial Disc is approved in the U.S. for the treatment of degenerative disc disease at one level from L4 to S1 in skeletally mature patients (with additional indications and contraindications as allowed by the FDA). Popular belief seems to indicate a bias towards not using arthroplasty as a treatment for DDD in patients over the age of 45 who are otherwise indicated for this treatment, thereby reserving this treatment for “younger” patients. Prior authors have described results of lumbar arthroplasty in different age groups as part of a one- or two-site review of an IDE study, or as part of a retrospective case series. However, there have been no reports of the age effect on clinical outcome as part of a completed prospective, multi-center, controlled clinical trial.

PURPOSE: To determine the effect of age on clinical outcome in patients undergoing lumbar arthroplasty at one level for the treatment of DDD.

STUDY DESIGN/SETTING: Prospective, multi-center, randomized, controlled trial.

PATIENT SAMPLE: 276 patients enrolled in the IDE study of the Charité Artificial Disc having undergone a one-level arthroplasty procedure.

OUTCOME MEASURES: Oswestry Disability Index, Visual Analog Scale (0–100) for pain, SF-36 Health Survey, Patient Satisfaction, Adverse Events.

METHODS: The methods for the IDE study of the Charité Artificial Disc were previously described by multiple authors, most recently, Blumenthal et al. Inclusion criteria for the study included patients 18–60 years of age. The data were analyzed for the effects of age on clinical outcome, patient satisfaction, and adverse events. There were 71 patients enrolled in the nonrandomized arm of the study, and 205 enrolled in the randomized arm, all (n=276) receiving the arthoplasty treatment at one level. Enrolled patients were split into two groups by age, 18–45 and 46–60, respectively. There were 217 patients 18–45 years of age, and 59 patients 46–60 years of age.

RESULTS: There was no significant difference between the groups with respect to level implanted, operative time, or blood loss (p>.10). There was no significant difference in change in mean ODI scores, VAS scores, nor any of the eight component scores of the SF-36 Health Survey, compared with baseline, at all time points through the 24-month follow-up (p>.10). Patient satisfaction (satisfied + somewhat satisfied) was equivalent at 24 months, 18–45 (87%), 46–60 (85%) with no statistical difference (p>.10). Of patients who would have the same treatment again, 79% in the 18–45 group and 81% in the 46–60 group answered affirmatively (p>.10). No significant differences were identified with respect to adverse events between the groups including approach-related, infection, major neurological, prosthesis-related, or additional surgery at index level categories, respectively, as previously described by Blumenthal, and Geisler et al.

CONCLUSIONS: Patients over 45 years of age may have co-morbidities or may be contraindicated for arthroplasty for a number of reasons, particularly osteopenia. However, this analysis demonstrates that in patients who are indicated for one-level arthroplasty, there are no differences in clinical outcome, patient satisfaction, or adverse events in patients 46–60 years of age compared with their younger counterparts.

FDA DEVICE/DRUG STATUS: Charité Artificial Disc: Approved for this indication.

CONFLICT OF INTEREST: Authors (RG, SLB, FHG, PCM) Consultant: DePuy Spine.