Relationship of Body Mass Index on Patient-Reported Outcomes After Platelet-Rich Plasma Versus Microfragmented Adipose Tissue for Knee Osteoarthritis

Objective: Body mass index is known to contribute to outcomes for patients with knee osteoarthritis. Furthermore, body mass index influences the protein expression of orthobiologic treatments like platelet-rich plasma and microfragmented adipose tissue. We performed a secondary analysis of the association of body mass index with patient-reported outcomes for patients with knee osteoarthritis who received either platelet-rich plasma or microfragmented adipose tissue injections. Methods: Seventy-one patients with knee osteoarthritis were randomized to receive a single ultrasound-guided injection of platelet-rich plasma or microfragmented adipose tissue. Platelet-rich plasma was created from 180 cc of anticoagulated blood and processed using a double-spin, buffy-coat concentration system. Microfragmented adipose tissue was created using autologous lipoaspirate that was processed according to minimal manipulation guidelines. Patient-reported outcomes and osteoarthritis outcome scores (Knee Osteoarthritis and injury Outcome Score) were tracked for 12 mos. Results: Forty-nine patients (platelet-rich plasma = 23, microfragmented adipose tissue = 26) completed 12-mo follow-up. Knee Osteoarthritis and injury Outcome Score quality of life and activity of daily living subscores were inversely correlated (both P < 0.05) with body mass index in the microfragmented adipose tissue but not platelet-rich plasmagroup. Knee Osteoarthritis and injury Outcome Score pain and sport subscores showed a trend toward inverse correlation with body mass index in the microfragmented adipose tissue group (P = 0.07 and P = 0.06, respectively), but not platelet-rich plasma. Conclusions: Body mass index was negatively associated with patient-reported outcomes in patients who received microfragmented adipose tissue injections for knee osteoarthritis, but not for patients receiving platelet-rich plasma.