Introduction: The results of platelet-rich plasma (PRP) in spinal fusion applications are limited and controversial. Both beneficial and inhibitory effects have been shown. In this prospective randomised controlled trial, our objective was to assess both the clinical and radiological effect of PRP when added to autograft iliac crest bone in posterior lumbar interbody fusion.
Methods and materials: Forty patients were recruited for the study fulfilling strict entry requirements and were randomised with a 1:1 ratio. In each group, one patient was lost to follow-up. Thirtyeight patients completed the Visual Analogue Scale (VAS), the Oswestry Disability Index (ODI), and the Short-Form 36 (SF-36) preoperatively and postoperatively at 3, 6, 12, and 24 months, respectively. CT-scans of the lumbar spine were taken at 3, 6, and 12 months. Posterior stabilisation was achieved with pedicle screws and interbody fusion was aimed at with carbon cages filled with autologous bone.
Results: Baseline demographic data (age, sex, smoking history, preoperative outcome measures) showed no relevant difference between groups. For patients who received autograft only, the mean VAS improved by 4.0 points (p < 0.01), mean ODI improved by 32.1 points (p < 0.001), and mean SF-36 showed statistically significant improvement in each of the eight domains and in the physical (p < 0.001) and mental (p < 0.001) component summary measures. For patients who received autograft with PRP, the mean VAS improved by 4.92 points (p < 0.01), mean ODI improved by 30 points (p < 0.001), and mean SF-36 showed statistically significant improvement in six of the eight domains (p < 0.02) and in the physical (p = 0.016) and mental (p < 0.001) component summary measures. The improvement of the VAS score and the physical component summary score was more pronounced in patients who received autograft with PRP. These differences were, however, not statistically significant. CT-scans showed uneventful osseous healing in all but one patient with no difference between groups.
Conclusion: In this prospective randomised controlled clinical and radiological trial, adding PRP in posterior lumbar interbody fusion did not lead to a substantial improvement or deterioration when compared with autologous bone only. No inhibitory effect of PRP was observed on CT-scans. From a clinical and radiological point of view, the use of PRP seems to be justified in posterior lumbar interbody fusion surgery. From an economical point of view, the expense of using PRP cannot be justified until statistical significance can be reached in a larger study.