Background
Post-spinal back pain is suggested to occur as a result of a localized inflammatory response that is often associated with some degree of muscle spasm. We aimed to evaluate the effect of platelet-rich plasma (PRP) in reducing the incidence of post-spinal back pain.

Methods
One hundred patients were randomly enrolled and scheduled for elective gynecological surgery under spinal anesthesia. After the subarachnoid block, group A (placebo) received 2 mL of sodium chloride 0.9% injected into the track of spinal needle during its withdrawal (2 mm after outward withdrawal in muscles and subcutaneous tissues). While patients in group B (PRP); received 2 ml of PRP injected into the track of the spinal needle during its withdrawal. The primary outcome was the number of patients who developed post-spinal low back pain within the first week following the subarachnoid block. Secondary outcomes included the time of the first analgesic request and total meperidine consumption during the first 24 h postoperatively.

Results
Fifteen patients in the PRP group developed low back pain during the first week following subarachnoid block compared to 26 patients in the placebo group (p = 0.037). There was a significant decrease in the mean meperidine consumption during first 24 h postoperatively in PRP group (174 ± 14 mg) compared to placebo group (210 ± 22 mg) (p < 0.0001). Also, the first analgesic request was significantly delayed in PRP group (243 ± 21 min.) compared to placebo group (185 ± 31 min.) (p < 0.0001).

Conclusion
This study demonstrated the positive effects of platelet-rich plasma on the prevention of post-spinal backache.