Platelet rich plasma for knee osteoarthritis - the RESTORE trial

INTERVENTION: Platelet‐rich plasma (PRP) injections into the knee joint. PRP injections are made from withdrawing and centrifuging the participant’s own blood on the day of treatment. An injection of PRP will be administered to participant’s study knee by a qualified doctor under ultrasound guidance once per week for three weeks. Approximately 20mL of blood from the participant’s arm will be drawn. A research nurse will prepare the injection, and both the participant and injecting doctor will not be told which treatment group the participant is allocated to. The whole blood sample will be centrifuged in a separate room to allow extraction of the PRP. A portion of the PRP will be withdrawn and saved for analysis, and approximately 5mL withdrawn into a syringe. The syringe will then be covered with a patient label, such that the injecting doctor will not know or be able to tell whether the syringe has PRP or placebo (saline). The doctor will then inject local anaesthetic superficially (which is optional for the participant), and then perform the PRP injection in to the knee joint under ultrasound guidance. Participants will return to the site radiology clinic for their second injection of PRP approximately one week later, and again for a third and final injection approximately one week after that. The injection process will be the same as the first injection. CONDITION: Knee osteoarthritis PRIMARY OUTCOME: Medial tibial cartilage volume. ; ; A MRI will be performed of the study knee using a 3T whole body system with dedicated extremity coil and a T1‐weighted fat suppressed 3D gradient recall acquisition sequence. Overall knee pain. ; ; Scored on an 11‐point numerical rating scale for average overall pain in the last week where 0=no pain and 10=worst pain possible. SECONDARY OUTCOME: Bone marrow lesions (BML) score in the medial tibiofemoral compartment. ; ; Assessed from the MRIs using Categorical scoring (range 0‐3 per region). Range 0‐6. Medial tibia and medial femoral condyle region BML scores are added. Cartilage defects score in the medial tibiofemoral compartment. ; ; Assessed from the MRIs using Categorical scoring (range 0‐4 per region). Range 0‐8. Medial tibia and medial femoral condyle region cartilage defect scores are added. Global change in pain. ; ; Scored from a 7‐point Likert scale from “much worse” to “much better” when compared to baseline. Those “moderately better” or “much better” will be classified as improved. Global change in physical function. ; ; Scored from a 7‐point Likert scale from “much worse” to “much better” when compared to baseline. Those “moderately better” or “much better” will be classified as improved. Global change overall. ; ; Scored from a 7‐point Likert scale from “much worse” to “much better” when compared to baseline. Those “moderately better” or “much better” will be classified as improved. ICOAP Intermittent knee pain. ; ; Scored from 6‐items regarding intermittent knee pain in the previous week. Ranges from 0 to 100; higher scores indicate worse pain. Intermittent and Constant Osteoarthritis Pain (ICOAP) Constant knee pain. ; ; Scored from 5‐items regarding constant knee pain in the previous week. Ranges from 0 to 100; higher scores indicate worse pain. KOOS Function in Daily Living. ; ; Scored from 17 questions regarding knee function in the last week. Ranges from 0 to 100; lower scores indicate worse function. KOOS Function in Sport and Recreation. ; ; Scored from 5 questions regarding knee function in the last week. Ranges from 0 to 100; lower scores indicate worse function. KOOS Knee‐related Quality of Life. ; ; Scored from 4 questions regarding knee related quality of life in the last week. Ranges from 0 to 100; lower scores indicate worse quality of life. KOOS Other Symptoms. ; ; Scored from 7 questions regarding knee symptoms in the last week. Ranges from 0 to 100; lower scores indicate worse symptoms. Knee Osteoarthritis Outcome Score (KOOS) Pain. ; ; Scored from 9 questions regarding knee pain in the last week. Ranges from 0 to 100; lower scores indicate worse pain. MOAKS Cartilage Morphology sub‐score. ; ; Number of areas with worsening in thickness at 12 months compared to baseline: Categorised as 0, 1, 2, or 3+. MOAKS Inter‐Condylar Synovitis sub‐score. ; ; Worsening in inter‐condylar synovitis at 12 months compared to baseline. Yes or No. MOAKS Whole Knee Effusion. ; ; Change in Whole Knee Effusion at 12 months compared to baseline: Categorised as Worsened, No Change or Improved. MRI Osteoarthritis Knee Score (MOAKS) Meniscal Morphology sub‐score. ; ; Any regions with worsening at 12 months compared to baseline. Yes or No. Physical Activity Scale for the Elderly (PASE). ; ; Physical activity levels in the last week will be assessed using the PASE. Ranges from 0 to 400+; higher scores indicate greater levels of physical activity. Quality of life (AQoL‐8D). ; ; Health‐related quality of life evaluated with the 35‐item Assessment of Quality of Life Instrument (8D version). Ranges from ‐0.04 to 1.00; higher scores indicate better quality of life. Walking knee pain. ; ; Scored on an 11‐point numerical rating scale for average pain on walking in the last week where 0=no pain and 10=worst pain possible. INCLUSION CRITERIA: 1) aged greater than or equal to 50 years; 2) knee pain on most days in the last month; 3) tibiofemoral osteophytes on x‐ray; and 4) A minimum pain score of 4 on an 11‐point numeric rating scale for the last week.