The relationship of body mass index on patient reported outcomes after platelet-rich plasma versus microfragmented adipose tissue for knee osteoarthritis: A secondary analysis of a randomized controlled trial

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.