The effect of electrical stimulation on lumbar spinal fusion in older patients: a randomized, controlled, multi-center trial: part 2: fusion rates.
METHODS
Randomized, controlled, multi-center trial.


OBJECTIVE
To investigate the effect of direct current (DC) electrical stimulation on fusion rates after lumbar spinal fusion in patients older than 60 years.


BACKGROUND
Older patients have increased complication rates after spinal fusion surgery. Treatments which have the possibility of enhancing functional outcome and fusion rates without lengthening the procedure could prove beneficial. DC-stimulation of spinal fusion has proven effective in increasing fusion rates in younger and "high risk" patients, but little information exist on the effect in older patients.


METHODS
A randomized clinical trial comprising 5 orthopedic centers. The study included a total of 107 patients randomized to uninstrumented posterolateral lumbar spinal fusion with or without DC-stimulation. Fusion rate was assessed at 2 year follow-up using thin slice CT. Functional outcome was assessed using Dallas Pain Questionnaire and Low Back Pain Rating Scale pain index. RESULTS.: Available follow-up after 2 years was 89% (84 of 95 patients). Fusion rates were surprisingly low. DC-stimulation had no effect on fusion rate: 35% versus 36% in controls. Other factors associated with low fusion rates were female gender (32% vs. 42% in males, P = 0.050) and smoking (21% vs. 42% in nonsmokers, P = 0.079). Patients who achieved a solid fusion as determined by CT had superior functional outcome and pain scores at their latest follow-up.


CONCLUSIONS
Thin slice CT revealed very high nonunion rates after uninstrumented spinal fusion in older patients. DC-stimulation was not effective in increasing fusion rates in this patient population. The achievement of a solid fusion was associated with superior functional outcome.
Andersen
Thomas
T
Orthopaedic Department E, Spine Section, Aarhus University Hospital, Aarhus, Denmark.
Christensen
Finn B
FB
Egund
Niels
N
Ernst
Carsten
C
Fruensgaard
Søren
S
Østergaard
Jørgen
J
Andersen
Jens Langer
JL
Rasmussen
Sten
S
Niedermann
Bent
B
Høy
Kristian
K
Helmig
Peter
P
Holm
Randi
R
Lindblad
Bent Erling
BE
Hansen
Ebbe Stender
ES
Bünger
Cody
C
D000368:Aged; D000369:Aged, 80 and over; D004599:Electric Stimulation Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011182:Postoperative Care; D011184:Postoperative Period; D012737:Sex Factors; D012907:Smoking; D013123:Spinal Fusion; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome