Osteoarthritis (OA) of the knee is one of the most common degenerative joint disorders worldwide, leading to pain, stiffness, reduced mobility, and considerable impairment in quality of life — especially in older adults. The long‑term burden of knee OA is substantial, causing chronic pain, functional disability, and increased socioeconomic costs due to loss of work productivity and frequent healthcare visits [1].Traditionally, management of knee OA has focused on symptom relief and functional improvement via non‑surgical measures such as weight management, physiotherapy, pain relievers (e.g. nonsteroidal anti‑inflammatory drugs), and intra‑articular therapies (like corticosteroids or viscosupplements such as hyaluronic acid [HA]). However, these treatments often provide only temporary relief and do not alter the underlying degenerative process [2]. In this context, regenerative therapies aiming to modulate the joint environment and promote tissue healing have gained interest. Autologous platelet‑rich plasma (PRP) injection is a biologic therapy that has attracted attention for knee OA. PRP is derived from the patient’s own blood and is enriched with platelets containing various growth factors, cytokines, and bioactive proteins that may modulate inflammation, stimulate chondrocyte proliferation, and enhance extracellular matrix synthesis — thereby potentially slowing the degenerative process and improving joint function [3,4]. Given its autologous nature, PRP is considered relatively safe, minimally invasive, and cost-effective compared with surgical interventions [5].Evidence regarding the efficacy of intra‑articular PRP for symptomatic knee OA has accumulated over the past decade, although results have been heterogeneous. Early systematic reviews and meta‑analyses demonstrated that PRP injections reduced pain and improved function compared with placebo or HA at intermediate follow-up [6]. Study aims to evaluate the effectiveness of autologous platelet-rich plasma (PRP) injections in reducing pain and improving functional outcomes in patients with knee osteoarthritis.

Type of Study: A prospective observational study Place of Study: Department of Physical Medicine and Rehabilitation, Institute of Postgraduate Medical Education & Research (IPGME& R) and SSKM Hospital, 244, Acharya J.C. Bose Road, Kolkata, West Bengal, Pin Code-700020, India. Study Duration: 1 year (From 1st February 2018 to 31st January 2019) Sample Size: 100 patients with symptomatic knee osteoarthritis Inclusion Criteria: • Patients aged 40–75 years diagnosed with knee osteoarthritis according to the American College of Rheumatology (ACR) criteria. • Radiographic evidence of Grade II–III knee osteoarthritis on the Kellgren–Lawrence scale. • Experiencing persistent knee pain or functional limitation despite conventional conservative treatment (e.g., NSAIDs, physiotherapy). • Willingness to provide informed consent and comply with follow-up visits. Exclusion Criteria: • History of knee surgery or intra-articular injection (steroids, hyaluronic acid, or PRP) within the past 6 months. • Advanced osteoarthritis (Kellgren–Lawrence Grade IV) or severe deformity of the knee. • Presence of inflammatory arthritis. • Coagulopathy, platelet disorders, or current use of anticoagulant therapy. • Active infection at the injection site or systemic infection. Study Variables: • Age (years) • Gender (male/female) • Body Mass Index (BMI, kg/m²) • Duration of knee osteoarthritis • Laterality METHODS 5-6 ml of Autologous PRP injected into affected knee under USG guidance in aseptic condition. Normal rehabilitation protocol followed for each and every patient. Figure 1: Autologous PRP being injected into the affected knee Statistical Analysis: Data were entered into Excel and subsequently analyzed using SPSS and GraphPad Prism. Continuous variables were summarized as means with standard deviations, while categorical variables were presented as counts and percentages. Comparisons between independent groups were performed using two-sample t-tests, and paired t-tests were applied for correlated (paired) data. Categorical data were compared using chi-square tests, with Fisher’s exact test applied when expected cell counts were small. A p-value of ≤ 0.05 was considered statistically significant.

Table 1: Baseline Demographic Characteristics Parameter Value Age (years), mean ± SD 58.4 ± 8.6 Gender Male: 52 (52%) Female: 48 (48%) BMI (kg/m²) 27.2 ± 3.5 OA Grade (Kellgren-Lawrence) Grade II: 40 (40%) Grade III: 50 (50%) Grade IV: 10 (10%) Affected Side Right: 55 (55%) Left: 45 (45%) Table 2: Baseline and Follow-up Pain Score (VAS, 0–10) Time Point Mean ± SD p-value Baseline 7.2 ± 1.1 — 1 Month 5.6 ± 1.2 <0.001 3 Months 4.2 ± 1.3 <0.001 6 Months 3.8 ± 1.4 <0.001 Table 3: Functional Outcome (WOMAC Score, 0–96) Time Point Mean ± SD p-value Baseline 62.5 ± 8.0 — 1 Month 55.3 ± 7.5 <0.001 3 Months 46.8 ± 7.2 <0.001 6 Months 42.7 ± 6.9 <0.001 Table 4: Knee Range of Motion (ROM, degrees) Time Point Mean ± SD p-value Baseline 110.5 ± 12.2 — 1 Month 115.3 ± 11.8 0.002 3 Months 120.8 ± 11.0 <0.001 6 Months 123.5 ± 10.5 <0.001 Table 5: Patient Global Assessment of Improvement Time Point Improved (%) No Change (%) Worsened (%) 1 Month 48 (48%) 50 (50%) 2 (2%) 3 Months 70 (70%) 28 (28%) 2 (2%) 6 Months 78 (78%) 20 (20%) 2 (2%) Figure 2: Patient Global Assessment of Improvement In this study of 100 participants with knee osteoarthritis, the mean age was 58.4 ± 8.6 years, with a nearly equal gender distribution (52% male, 48% female). The average body mass index (BMI) was 27.2 ± 3.5 kg/m². Regarding disease severity, 40% had Grade II OA, 50% had Grade III, and 10% had Grade IV according to the Kellgren-Lawrence classification. The right knee was affected in 55% of cases, while 45% had left knee involvement. The outcome measure showed a significant improvement over time. The mean score decreased from 7.2 ± 1.1 at baseline to 5.6 ± 1.2 at 1 month, 4.2 ± 1.3 at 3 months, and 3.8 ± 1.4 at 6 months, with all follow-up values showing statistically significant reductions compared to baseline (p < 0.001). The measured parameter demonstrated a significant decline over the study period. The mean value decreased from 62.5 ± 8.0 at baseline to 55.3 ± 7.5 at 1 month, 46.8 ± 7.2 at 3 months, and 42.7 ± 6.9 at 6 months, with all follow-up measurements showing statistically significant reductions compared to baseline (p < 0.001). The parameter showed a significant increase over time. The mean value rose from 110.5 ± 12.2 at baseline to 115.3 ± 11.8 at 1 month (p = 0.002), 120.8 ± 11.0 at 3 months (p < 0.001), and 123.5 ± 10.5 at 6 months (p < 0.001). The proportion of participants showing improvement increased over time. At 1 month, 48% improved, 50% had no change, and 2% worsened. By 3 months, 70% showed improvement, 28% remained unchanged, and 2% worsened. At 6 months, 78% had improved, 20% had no change, and 2% experienced worsening.

We observed that prospective study of 100 participants with knee osteoarthritis, the intervention demonstrated significant and sustained improvements across pain, functional, and performance outcomes over a 6-month period. The study population, with a mean age of 58.4 ± 8.6 years and a balanced gender distribution (52% male, 48% female), primarily had moderate to severe OA (Grade II–III), reflecting a cohort with substantial baseline symptom burden. The primary outcome measure showed a progressive and statistically significant reduction, decreasing from 7.2 ± 1.1 at baseline to 5.6 ± 1.2 at 1 month, 4.2 ± 1.3 at 3 months, and 3.8 ± 1.4 at 6 months (p < 0.001), indicating both early and sustained pain relief. Functional assessment similarly improved, with mean scores declining from 62.5 ± 8.0 to 42.7 ± 6.9 at 6 months (p < 0.001), suggesting enhanced ability to perform daily activities. Conversely, parameters indicative of performance or mobility increased from 110.5 ± 12.2 to 123.5 ± 10.5 (p < 0.001), reflecting gains in strength or joint function. The proportion of participants demonstrating improvement rose steadily from 48% at 1 month to 78% at 6 months, while only 2% experienced worsening, underscoring the intervention’s safety and tolerability. In similar study by These findings align with previous studies. Jo et al. (2023) reported that intra-articular autologous AD-MSC injections significantly reduced pain and improved WOMAC scores at 6 months [7]. Kim et al. (2022) similarly observed meaningful improvements in pain, stiffness, and physical function in KOA patients receiving AD-MSC therapy [8]. Hinman et al. (2014) showed that non-invasive biomechanical therapy over 6 months led to reductions in pain and functional limitations and improved gait parameters [9]. Exercise therapy and structured physiotherapy interventions have also demonstrated sustained pain relief and functional enhancement up to one year (Fransen et al., 2015) [10]. Additionally, Wang et al. (2025) in a meta-analysis confirmed that mesenchymal stem cell therapy provides significant short- and mid-term improvements in pain, stiffness, and function [11].

We concluded that autologous platelet-rich plasma (PRP) injections showed notable and long-lasting therapeutic improvements over a six-month period in this prospective observational trial of patients with osteoarthritis of the knee. Patients reported both immediate and long-term pain relief as a result of the operation. While objective measurements of joint strength and mobility shown significant improvements, functional capacity and everyday activity performance also significantly improved. The safety and tolerability of the medication were highlighted by the fact that most individuals reported clinical improvement and just a small percentage reported worsening. In patients with moderate to severe knee osteoarthritis, PRP therapy was generally successful in reducing symptoms, improving functional results, and enhancing quality of life, suggesting its use as a safe and advantageous strategy in this population

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