Single Injection of High Volume of Autologous Pure PRP Provides a Significant Improvement in Knee Osteoarthritis: A Prospective Routine Care Study.

BACKGROUND: Evidence is growing regarding the ability of platelet-rich plasma (PRP) injections to enhance functional capacity and alleviate pain in knee osteoarthritis (OA). However, heterogeneity in common practice regarding PRP preparation and biological content makes the initiation of this activity in a hospital complex. The aim of this study was to document the efficacy of a single PRP injection to treat knee OA and validate a routine care procedure. METHODS: Fifty-seven patients with symptomatic knee OA received a single injection of large volume of very pure PRP. They were assessed at baseline and after one, three and six months, by measuring Knee Injury and Osteoarthritis Score (KOOS), Observed Pain after a 50-foot walk test and Visual Analog Scale (VAS) assessments. Magnetic Resonance Imaging (MRI) analysis was performed at baseline and six months after the procedure. The objective was to recover 50% of responders three months after the procedure using OMERACT-OARSI criteria. RESULTS: A single administration of high volume pure PRP provided significant clinical benefit for 84.2% of the responders, three months after the procedure. The KOOS total score significantly increased from 43.5 ± 14.3 to 66.4 ± 21.7 six months after the procedure (p < 0.001). Pain also significantly decreased from 37.5 ± 25.1 to 12.9 ± 20.9 (p < 0.001). No difference was observed on MRI parameters. CONCLUSION: A single injection of large volume of very pure PRP is associated with significant functional improvement and pain relief, allowing initiation of daily PRP injection within our hospital.

How to evaluate and improve the reliability of power Doppler ultrasonography for assessing enthesitis in spondylarthritis.

OBJECTIVE: To evaluate and improve the reliability of power Doppler ultrasonography (PDUS) for detecting and scoring enthesitis in patients with spondylarthitis, using a 3-step procedure. METHODS: In the first step, we evaluated the reliability of 5 sonographers by bilaterally scanning 5 entheses twice in 5 patients. In the second step, starting from disagreements observed during the first step, we established consensus guidelines. The sonographers' implementation was further evaluated in 2 reliability exercises: one on 60 PDUS enthesitis images and the other by scanning 5 new patients. In the third step, we performed a final reliability evaluation of 5 additional patients after 1 year. Kappa coefficients (kappa) as well as variance component analysis (VCA) and generalizability theory (GT) were used to assess reliability. RESULTS: The initial intra- and interobserver reliability were poor, especially for detecting and scoring Doppler signal. VCA and GT showed that most variability was accounted for by interaction between sonographer and enthesis. Implementation of consensus guidelines was associated with a significant improvement in Doppler reliability between the first and second steps (mean interobserver kappa increased from 0.13 to 0.51 for binary Doppler scoring in patients; P < 0.005), which persisted in the third step (mean interobserver kappa = 0.57). The high GT coefficients reached in the last steps supported such improvement. CONCLUSION: The 3-step procedure used in this study to standardize PDUS technique was associated with a significant improvement in interobserver reliability for detecting enthesitis in spondylarthritis patients. Such an approach can be useful to standardize PDUS assessment of musculoskeletal disorders.