Leukocyte-Rich Platelet-Rich Plasma Injection in an Acute-on-Chronic Rectus Femoris Injury of a Professional Soccer Player: A Case Report.

This is the case of an 18-year-old male professional soccer player, an attacking midfielder, who presented acute-onset pain in his right thigh during a training match but continued playing and training until the end of the session. Two weeks after the initial symptoms, the athlete's pain increased after kicking the ball and stopping training. He came for consultation a week later with tenderness in his right thigh and impaired gait. A 3 â€‹cm gap in his right mid-quadriceps muscle and tenderness during resisted knee extension and leg raises with no hip or knee range of motion limitations were observed on physical examination. He was scheduled for magnetic resonance imaging (MRI) after the consultation, revealing an acute-on-chronic type 2A lateral muscle tear of the distal rectus femoris. A 2 â€‹ml seroma aspiration was performed five weeks after the initial injury with a subsequent intra-lesional 1 â€‹ml liquid leukocyte-rich platelet-rich plasma (LR-PRP) injection using intermittent ultrasound guidance within 5 â€‹min after preparation. The LR-PRP preparation was classified as 3 14-1 3-0 0 according to the Universal Coding System (UCS) by Kon et al. Nine physiotherapy sessions, including an initial assessment, were conducted over five weeks. The rehabilitation started with pulley exercises with hip flexion, tension arch, leg extension, and squatting with supporting exercises for core and hip strength, with a gradual increase in loading. As the player's symptoms improved, he started doing eccentric exercises such as the reverse Nordics and leg extension. He also followed a running program, gradually increasing speed to a full sprint without pain or irritation. The return-to-sports clearance consultation was conducted seven weeks after the injury, previously confirming satisfactory healing on an MRI. The patient was cleared after passing the Rehabilitation Department battery tests and physical examination. The patient was asymptomatic and had no complaints despite his right quadriceps gap, returning to competition nine weeks after injury. After a one-year follow-up, the patient remains playing at a competitive level, asymptomatic, with no reported reinjury. Adequate reporting of rehabilitation programs and PRP injection characterization is crucial for future research quality improvement and reproducibility.

Review of Dohan Eherenfest et al. (2009) on "Classification of platelet concentrates: From pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)".

This classic discusses the original publication of Dohan Eherenfest et al. on "Classification of platelet concentrates: from pure platelet-rich plasma (P-PRP) to leucocyte- and platelet-rich fibrin (L-PRF)", in which the authors propose four categories of platelet concentrates depending on their leucocyte and fibrin content (P-PRP, leucocyte- and platelet-rich plasma (L-PRP), pure platelet-rich fibrin (P-PRF), and L-PRF) to group a "jungle" of products in which the term platelet-rich plasma (PRP) was used indistinctly. They were able to identify common factors such as: (1) the use of anticoagulants and immediate centrifugation of the blood after its collection; (2) most preparation techniques allowed platelet concentrate preparation within an hour; (3) the centrifugation aimed to separate the blood in layers that would allow the extraction of specific fractions; and (4) the product was activated with thrombin or calcium chloride. The reviewed manuscript has been listed among the most cited PRP articles in regenerative medicine, with more than 800 citations, driving current scientific research and clinical practise by categorising L-PRP and P-PRP (now, leucocyte-poor PRP). The classification has also opened the door to understanding intrinsic biological mechanisms between platelets, leukocytes, fibrin, and growth factors, which will later be considered for studying the proliferation and differentiation of cells in different tissues affected by PRP. Since the initial classification of platelet concentrates, several other classification systems have been proposed and published in the current literature such as platelet, activation, white blood cell (PAW), Mishra, platelet, leucocyte, red blood cells, and activation (PLRA), dose of platelet, efficiency, purity, and activation (DEPA), method, activation, red blood cells, spin, platelets, image guidance, leukocytes, and light activation (MARSPILL), etc. These classifications have identified important aspects of PRP that affect the biological composition and, ultimately, the indications and outcomes. To date, there is still a lack of standardisation in sample preparation, cohort heterogeneity, and incomplete reporting of sample preparation utilised, leading to a lack of clarity and challenging researchers and clinicians.

Knee Osteoarthritis: Clinical and MRI Outcomes After Multiple Intra-Articular Injections With Expanded Autologous Adipose-Derived Stromal Cells or Platelet-Rich Plasma.

OBJECTIVE: To directly compare clinical and MRI outcomes of multiple intra-articular injections of adipose-derived stromal cells (ASCs) or platelet-rich plasma (PRP) in patients with knee osteoarthritis (OA). DESIGN: We retrospectively compared 24-month outcomes in (1) 27 patients receiving 3-monthly intra-articular injections with a total of 43.8 million ASCs and (2) 23 patients receiving 3-monthly injections of 3-ml preparation of PRP. All patients had Kellgren-Lawrence grade 1, 2, or 3 knee OA with failed conservative medical therapy. The Numeric Pain Rating Scale (NPRS) scores; Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 6, 12, and 24 months after the first injection; and the MRI Osteoarthritis Knee Score (MOAKS) at 12 and 24 months were considered as outcomes. RESULTS: No major complications occurred in any patient. Both groups significantly improved in pain NPRS score and KOOS at 6 months. At 12- and 24-month evaluations, the ASC group significantly decreased scores to a greater degree (P < 0.001) than the PRP group. MOAKS scores indicated a decrease in disease progression in the ASC group. CONCLUSION: Both ASCs and PRP were safe and resulted in clinical improvement in patients with knee OA at 6 months; however, at 12 and 24 months, ASCs outperformed leukocyte-poor PRP in clinical and radiological outcomes.

The immediate effects of foot orthoses on hip and knee kinematics and muscle activity during a functional step-up task in individuals with patellofemoral pain.

BACKGROUND: Evidence shows that anti-pronating foot orthoses improve patellofemoral pain, but there is a paucity of evidence concerning mechanisms. We investigated the immediate effects of prefabricated foot orthoses on (i) hip and knee kinematics; (ii) electromyography variables of vastus medialis oblique, vastus lateralis and gluteus medius during a functional step-up task, and (iii) associated clinical measures. METHODS: Hip muscle activity and kinematics were measured during a step-up task with and without an anti-pronating foot orthoses, in people (n=20, 9 M, 11 F) with patellofemoral pain. Additionally, we measured knee function, foot posture index, isometric hip abductor and knee extensor strength and weight-bearing ankle dorsiflexion. FINDINGS: Reduced hip adduction (0.82°, P=0.01), knee internal rotation (0.46°, P=0.03), and decreased gluteus medius peak amplitude (0.9mV, P=0.043) were observed after ground contact in the 'with orthoses' condition. With the addition of orthoses, a more pronated foot posture correlated with earlier vastus medialis oblique onset (r=-0.51, P=0.02) whilst higher Kujala scores correlated with earlier gluteus medius onset (r=0.52, P=0.02). INTERPRETATION: Although small in magnitude, reductions in hip adduction, knee internal rotation and gluteus medius amplitude observed immediately following orthoses application during a task that commonly aggravates symptoms, offer a potential mechanism for their effectiveness in patellofemoral pain management. Given the potential for cumulative effects of weight bearing repetitions completed with a foot orthoses, for example during repeated stair ascent, the differences are likely to be clinically meaningful.