Effect of Intraoperative Platelet-Rich-Plasma Treatment on Post Operative Donor Site Knee Pain in Patellar Tendon Autograft ACL Reconstruction: A Double-Blind Randomized Controlled Trial

OBJECTIVES: Donor site morbidity in the form of anterior knee pain is a frequent complication after bone-patellar tendon-bone (BPTB) autograft ACL reconstruction. The purpose of this Level I study was to examine the effect of the intraoperative administration of platelet-rich plasma on post operative knee pain and patellar defect healing. METHODS: Fifty-nine patients (29±12 y/o) undergoing BPTB ACL reconstruction and eligible to enter the study, were randomized to the treatment (PRP; n=31) or non treatment (sham n=28) arms of the study just prior to surgery. In either case, 10 cc of venous blood was drawn prior to the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks and 6 months after surgery, patients completed IKDC forms and VAS pain scores for ADLs and kneeling (0-10 scale). Healing indices at the donor site were assessed by MRI at 6 months and included the following measurements taken from axial sequences: AP tendon dimensions at the level of the superior tibial cortex, roof of the intercondylar notch and width at the largest patella graft deficit. Mixed model ANOVA was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing. The primary dependent variable was VAS kneeling pain. It was estimated that with 25 patients per group there would be 80% power to detect a 1.5-point difference in kneeling pain between treatments at P<0.05. A between group difference of 1.5-points in VAS for kneeling pain was deemed to represent a clinically relevant difference. RESULTS: VAS Kneeling Pain at 12 weeks tended to be lower in the PRP versus placebo group (4.5±3.6 vs. 6.2±2.4, P=0.051) but no difference was apparent at 6 months (3.7±3.2 vs. 4.4±2.9, P=0.41). Kneeling pain decreased from 12 weeks to 6 months (P<0.001) with a trend for a greater decrease in the placebo group (Time by Treatment P=0.097). VAS Pain with ADLs was not different between treatment groups at 12 weeks (PRP 2.0±2.3 vs. Placebo 2.8±1.8, P=0.16) or 6 months (1.5±1.9 vs. 1.7±2.1, P=0.60). Pain with ADLs decreased from 12 weeks to 6 months (P<0.05) with no difference between treatment groups (Time by Treatment P=0.52). IKDC scores improved from 12 weeks to 6 months (P<0.001), with no difference between treatment groups (Time by Treatment P=0.73). IKDC scores were not different between treatment groups at 12 weeks (64±16 vs. 64±12, P=0.83) or 6 months (75±18 vs. 73±11, P=0.66). MRI indices of donor site healing were not different between treatment groups (P=0.60 to 0.97). CONCLUSION: Whether randomized to receive PRP in their patellar defect or not, patients continued to have similar levels of kneeling pain and patellar defect sizes 6 months after BPTB ACL autograft reconstruction. The intraoperative administration of PRP into the patellar donor site following ACL reconstruction with BPTB autograft has no significant effect on the parameters of post operative knee pain or donor site healing.