The comparative effects of injecting intra-articular platelet-rich plasma and hypertonic dextrose prolotherapy in osteoarthritis knee - A randomized control trial

ABSTRACT

Introduction:

Knee osteoarthritis is an age-dependent disease caused by degenerative and healing processes in subchondral tissue of articular and bone cartilage, resulting in changes of its biochemical properties that eventually causes pain, stiffness, and decreased articular function. Therefore, this study aims to compare the effectiveness of platlet-rich plasma (PRP) therapy and 25% hypertonic dextrose (Dextrose) prolotherapy in patients with knee osteoarthritis.

Material and Methods:

Single-blind randomized control trial was conducted for 18 months. Patients satisfying the inclusion and exclusion criteria were enrolled from the indoor/outdoor facility of the Department of Physical Medicine and Rehabilitation, King George’s Medical University (KGMU), Lucknow, India. The informed consent form was duly signed by all the enrolled patients, who were randomly assigned into two groups by the computer-generated system, A total of 85 study participants in this group I (43 patients) received 5 ml Platelet-Rich Plasma (PRP) and Group II (42 patients) received 5 ml of 25% hypertonic dextrose prolotherapy (Dextrose). To compare the effect in terms of reduction of pain, according to the Numeric pain rating scale (NPRS) and Pain/Discomfort, Walking and Activities of Daily Living (ADL) according to the Lequesne Knee Index (LKI) and assessment of each patient was done at specified period, i.e., 0 weeks (Baseline means immediately before intervention), and 6 weeks after the intervention.

Result:

Overall, the baseline to 6 weeks change of LKI-Pain in group I (PRP) was significantly more than the group II (DEXTROSE) (P < 0.001). On considering the parameter of LKI-Pain at baseline and 6 weeks for PRP and Dextrose, it was found that in Group I, the mean ± SD reduced more at 6 weeks from 4.81 ± 1.55 to 2.44 ± 1.76 as compared to participants in Group II with 4.83 ± 1.17 at baseline to 6 weeks 3.64 ± 0.98, LKI-Activities of Daily Living (ADL) for group I PRP the Mean ± SD score dropped more from 4.66 ± 1.40 to 2.95 ± 1.35 whereas for group II Dextrose the Mean ± SD score dropped from 4.68 ± 1.40 to 3.65 ± 1.51 at baseline and 6 week respectively and At baseline, the mean LKI-Total score in group I was 12.85 ± 3.59 while in group II the mean score was 13.11 ± 3.15. At 6 weeks, the mean LKI-Total score in group I was 7.63 ± 3.85; in group II the mean score was 10.11 ± 2.93. A significant difference was found in the mean LKI-Total score between the groups at 6 weeks (P = 0.001) and found to be lesser in group I.

Conclusion:

It could thus be concluded that on considering the effect of platelet-rich plasma and 25% hypertonic dextrose prolotherapy in patients with knee osteoarthritis, significant improvement was seen in participants administered with both platelet-rich plasma and dextrose with the higher effect being with platelet-rich plasma.

Introduction

Osteoarthritis (OA) of the knee is a progressive disease involving the intra-articular tibia femoral and patella–femoral cartilage and all other surrounding intra-articular and peri-articular structures,[1] representing the most widespread cause of physical morbidity and impaired quality of life throughout the world. In India, the prevalence of osteoarthritis ranges from 22 to 39%. About 13% of women and 10% of men aged 50 years and older have symptomatic knee osteoarthritis.[2] Risk factors known for knee OA include advanced age, obesity, gender, history of trauma, improper lifestyle, and genetics.[3]

Knee osteoarthritis management includes a multimodal approach and prolotherapy is one of the methods that can raise growth factor levels or increase growth factor efficiency to stimulate tissue regeneration.[3]

The commonly used prolotherapy agent in clinical practice is dextrose, with concentrations ranging from 12.5% to 25%. It has been revealed that an increased extracellular glucose level can enhance the production of various polypeptide growth factors in a variety of human cells.[4,5]

Another reparative method to treat OA is platelet-rich plasma (PRP) treatment. The rationale for the use of PRP is to stimulate the natural healing cascade and tissue regeneration by a “supraphysiologic” release of platelet-derived factors directly at the site of treatment.[6] As such, PRP is safe, cheap, and effective, and no additional procedures are required. In a study done, it was concluded that PRP therapy is more effective in pain reduction and improvement in physical activity as compared to dextrose prolotharapy.[2] OBJECTIVES: To our knowledge, few literatures are evaluating the effectiveness of platelet-rich plasma and 25% hypertonic dextrose prolotherapy in knee OA, especially in the Indian population. Therefore, we aim to compare the effectiveness of PRP therapy and 25% hypertonic dextrose prolotherapy (Dextrose) in patients with knee osteoarthritis in terms of - (1) Reduction of pain, according to the Numeric Pain Rating Scale (NPRS), (2) Pain/Discomfort, Walking, and Activities of Daily Living (ADL) according to Lequesne Knee Index (LKI)

Methodology

A single-blind randomized control trial was conducted for a period of 18 months. Patients satisfying the inclusion and exclusion criteria were enrolled from the indoor/outdoor facility of the Dept. of PMR, King George’s Medical University, Lucknow. Ethical Clearance was taken from IEC, KGMU, Lucknow, India (Registration No. ECR/262/Inst/UP/2013/RR-19).

Sample size

A total of 85 study participants in Group I included 43 patients who received 5 ml Platelet-Rich Plasma (PRP) and Group II included 42 patients who received 5 ml of 25% hypertonic dextrose prolotherapy (Dextrose). At 95% Confidence Interval and 80% Power, Sample size estimation was done using the given formula: The notation for the formulae is:

n = sample size of Group

σ1 = standard deviation of first interval = 0.80

wσ2 = standard deviation of second interval = 0.87

Δ = difference in group means=0.47

Z1- α/2 = two-sided Z value (e.g., Z = 1.96 for 95% confidence interval).

Inclusion criteria

Patients Aged ≥50 to <75 years old, Diagnosis of primary knee OA based on clinical criteria as defined by the American College of Rheumatology Association,[7,8] Moderate-to-severe knee pain for at least 3 months, Failure to achieve pain and swelling reduction after 3 months of usual care, such as weight reduction, exercise, physical therapy, and pharmacological treatment, Radiographic evidence of knee OA (KL grade 1, grade 2, grade3) and patient willing to participate in the study.

Exclusion criteria

Patient history with uncontrolled Diabetes Mellitus, OA knee: KL grade 4, patient on anticoagulant therapy, Prior intra-articular knee injections within 3 months, other than platelet-rich plasma therapy (PRP therapy) and hypertonic dextrose prolotherapy, Inflammatory or post-infectious knee arthritis, such as clinically diagnosed rheumatoid arthritis, gouty arthritis, psoriatic arthritis and septic arthritis, A history of previous knee pathology or any recent trauma to the hip joint or in the pelvic region interfering with ADL or causing any deformity, Hb <10 gm/dl and platelet values <150,000/ml, paralysis of lower extremities, significant effusion, Any disease or medication that might have worsened physical function and interfered with the evaluation of knee pain or co-morbidity or lifestyle preventing participation in the study protocol, e.g., Malignancy, Mental disorder, Rheumatoid arthritis or spondyloarthritis, Symptomatic cerebrovascular disease, Parkinson’s disease, Polyneuropathies, Debilitating cardiovascular disease despite medication.

Assessment parameters

Clinical assessment: General Examination, Systemic Examination, Local Examination (knee joint), Radiological Examination[9]- Digital x-ray of the bilateral knee joint (anterior-posterior and lateral view in standing) the classification was done based on the Kellgren and Lawrence grading system (KL grading) and complete hemogram with ESR, blood sugar level, and any other investigation/reference required for the patient on an individual basis was done. Numeric Pain Rating Scale (NPRS)[10] and Lequesne Knee Index (LKI)[11] used in the present study was introduced by Lequesne et al.[11] to assess the severity of osteoarthritis for the knee with an aim to assess the effectiveness of therapeutic interventions. In the LKI, three major sections included-(1) Pain or discomfort (2) Maximum Distance Walked (MDW) (3) Activities of daily living (ADL), Minimum points for each section- 0, Maximum points for each section- 8, Minimum Index score- 0, Maximum Index score- 24. The informed consent form was duly signed by all the enrolled patients and were randomly assigned into two groups by computer-generated system.

Procedure technique

Following routine monitoring processes, a blood sample was withdrawn and autologous PRP in the Department of Transfusion Medicine, King George’s Medical University, Lucknow from the selected autologous donor was obtained. A standard double centrifugation protocol was used for PRP preparation, which includes processing of blood done in the ‘Component Lab’ from transfusion medicine department.

Steps for the preparation of Autologous Platelet-Rich Plasma (PRP) [Figures 1-3], blood was withdrawn from the patient (approximately 20 ml) under aseptic conditions from an autologous donor. The blood was collected in a quadruple bag containing the anticoagulant CPDA-1 (Citrate Phosphate Dextrose Adenine). A standard double centrifugation protocol was used for PRP preparation, involving the following steps:

Figure 1.

Cryofuge 6000i

Figure 3.

Blood bag

Figure 2.

Plasma expressor

1. The blood processing took place in the ‘Component Lab’ of the Department of Transfusion Medicine. PRP sedimentation was carried out using a closed system and a differential procedure.

2. The quadruple bag was placed in a centrifugation machine [Figure 1] and centrifuged at a speed of 890 rpm (soft spin) for 8 minutes.

3. The supernatant plasma, containing platelets, was then transferred into a platelet bag without anticoagulant and centrifuged again at a higher speed of 3150 rpm (hard spin) for 11 minutes to obtain a platelet concentrate.

4. The upper 2/3^rd portion, known as PPP (platelet poor plasma), was removed, and the lower 1/3 portion, PRP (Platelet-Rich Plasma, approximately 5 ml), was obtained in a closed bag [Figure 3]. The resulting concentrate was 3–4 times more concentrated with platelets compared to whole blood. This was initially and randomly checked using the manual counts of stained platelet smears to measure platelet concentration.[12,13,14,15]

In study group II, 100 ml of 25% weight/volume dextrose injection [Figure 4] was used, with 5 ml withdrawn for each patient under aseptic conditions. The patient was made to sit in the posture with the knee flexed 90° to afford better exposure of the intra-articular surface, which facilitated the ease of needle entry into the joint space as surface marking [Figure 5: P-patella, PT- patellar tendon, AL- anterolateral, AM- anteromedial, TT- tibial tuberosity]. The lateral or medial approach was selected according to the radiograph of the respective knee. Under complete aseptic precaution, intra-articular platelet-rich plasma [Figure 6] was given to the group I patient, and an intra-articular solution of 25% hypertonic dextrose was injected in group II with taking care of negative withdrawal just before injecting the solution. DISPOSAL OF MATERIAL: For safe disposal and infection control empty PRP bags were cut and disposed of in a yellow bin and sent to the biomedical waste management department.

Figure 4.

Injectable material for intra articular knee injection rocedure

Figure 5.

Surface marking for intra articular knee injection procedure

Figure 6.

Surface marking and Intra articular knee injection procedure with injectable material

Post-procedure protocol

Patients were advised to decrease weight bearing for 48 hours Post injection, remained under medical care for an hour, and were discharged in case of no complications. In case of flaring, NSAID was prescribed and rest was recommended.[16] Tab paracetamol 500 mg SOS was advised if the pain persisted. For some exercise programs, after 3 days of the injection to all the patients like Quadriceps strengthening, Straight Leg Raise, Gluteus strengthening (3 sets of 10 repetitions-once daily), Hamstring stretch, calf stretch (Hold of 30 seconds, 3 repetitions, once daily).[17] Squatting, cross-leg sitting, and use of stairs were asked to be avoided as much as possible.

Follow-up protocol

Assessment was done at 0 weeks (Baseline) and 6 weeks after the intervention.

Result

Statistical analysis- Data entry was made in MS Office Excel software in codes and analysis was done by SPSS software®. Results from OpenEpi, Version 3, open-source calculator—SSMean were obtained. Association with the factors was tested for significance using the Chi-square test and P < 0.05 was considered statistically significant. For intergroup comparisons unpaired t-test was used. Study Cases were divided into two groups. The first group containing 43 study participants received PRP as treatment while the second group 42 study participants received Dextrose.

Intergroup comparison of Numeric Pain Rating Scale (NPRS) score [Table 1] for group I PRP and group II dextrose at baseline and 6 weeks, the Mean ± SD value for participants in the PRP group at baseline was 7.14 ± 0.99, which dropped to 3.93 ± 1.37 at 6 weeks, whereas for group II dextrose the drop of value from baseline to 6 weeks was from 6.83 ± 1.10 to 5.12 ± 0.97. The reduction in NPRS score was higher for group I PRP as compared to group II dextrose with P-value significant at < 0.001.

Table 1.

Intergroup comparison of numeric pain rating scale (NPRS) score

NPRS	Group I (PRP)		Group II (Dextrose)		t	P
	Mean	SD	Mean	SD
Baseline	7.14	0.99	6.83	1.10	1.35	0.181
6 wk	3.93	1.37	5.12	0.97	−4.61	<0.001

On considering the intergroup comparison of Lequesne Knee Index-Pain (LKI-P) score [Table 2] at baseline and 6 weeks for PRP and Dextrose, it was found that in group I, the mean ± SD reduced more at 6 weeks from 4.81 ± 1.55 to 2.44 ± 1.76 as compared to participants in Group II with 4.83 ± 1.17 at baseline to 3.64 ± 0.98. A significant difference was found in the mean LKI-P score between the groups at 6 weeks (P < 0.001) and found to be lesser in group I.

Table 2.

Intergroup comparison of Lequesne knee index-pain (LKI-P) score

LKI-P	Group I (PRP)		Group II (Dextrose)		t	P
	Mean	SD	Mean	SD
Baseline	4.81	1.55	4.83	1.17	−0.07	0.948
6 wk	2.44	1.76	3.64	0.98	−3.87	<0.001

On the evaluation of intergroup comparison of Lequesne Knee Index-Maximum Distance Walk (LKI-MDW) score [Table 3] for Group I and Group II at baseline and at 6 weeks, at baseline for Group I mean ± SD was 3.37 ± 1.48 and at 6 weeks found to reduce to 2.23 ± 1.29, whereas for Group II mean ± SD was 3.60 ± 1.29 and at 6 week found to reduce to 2.81 ± 0.99, with P-value found to be significant at 0.023.

Table 3.

Intergroup comparison of Lequesne knee index-maximum distance walk (LKI-MDW) score

LKI-MDW	Group I (PRP)		Group II (Dextrose)		t	P
	Mean	SD	Mean	SD
Baseline	3.37	1.48	3.60	1.29	−0.74	0.461
6 wk	2.23	1.29	2.81	0.99	−2.31	0.023

On making the intergroup comparison of the Lequesne Knee Index-Activities of Daily Living (LKI-ADL) score [Table 4] for group I PRP the Mean ± SD score dropped from 4.66 ± 1.40 to 2.95 ± 1.35 whereas for group II Dextrose the Mean ± SD score dropped from 4.68 ± 1.40 to 3.65 ± 1.51 at baseline and 6 week, respectively. The drop in score was found to be higher for the PRP group as compared to the dextrose group with P-value found to be significant at 0.027.

Table 4.

Intergroup comparison of the Lequesne knee index-activities of daily living (LKI-ADL) score

LKI-ADL	Group I (PRP)		Group II (Dextrose)		t	P
	Mean	SD	Mean	SD
Baseline	4.66	1.40	4.68	1.40	−0.05	0.959
6 wk	2.95	1.35	3.65	1.51	−2.26	0.027

Intergroup comparison of LKI-total score [Table 5] At baseline, the mean LKI-total score in group I was 12.85 ± 3.59 while in group II the mean score was 13.11 ± 3.15. No significant difference was found in the mean LKI-Total score between the groups at baseline (P = 0.726). At 6 weeks, the mean LKI-Total score in group I was 7.63 ± 3.85 while in group II the mean score was 10.11 ± 2.93. A significant difference was found in the mean LKI-Total score between the groups at 6 weeks (P = 0.001) and found to be lesser in group I.

Table 5.

Intergroup comparison of LKI-total score

LKI-Total	Group I (PRP)		Group II (Dextrose)		t	P
	Mean	SD	Mean	SD
Baseline	12.85	3.59	13.11	3.15	-0.35	0.726
6 wk	7.63	3.85	10.11	2.93	-3.33	0.001

Discussion

The present study was a single-blind randomized control trial conducted to compare the effect of platelet-rich plasma and 25% hypertonic dextrose prolotherapy in patients with knee osteoarthritis. From 100% enumeration when gender distribution was considered male-female participants among Group I (PRP) was 09:34, whereas in Group II (Dextrose) was 21: 64 [Figure 7]. Similar finding was seen in the study done by Filardo G et al. (2021),[18] Evanich et al. (2001)[19] and Akinpelu AO et al. (2009)[20] where it was found that knee OA is a major cause of mobility impairment, particularly among females,[2] thus it is a known fact that knee OA is more common in women. When age was considered it was seen that the highest number of participants reporting for osteoarthritis knee were among the age group [Figure 8] of 50–58 years (n = 48), followed by 59–66 years (n = 25), followed by 67–74 years (n = 12). The findings are in correspondence with the study done by Pal et al. (2016)[2] and Rabago D. et al. (2015).[21] The reason for the higher prevalence of participants reporting OA knee among the age group of 50–58 years could be attributed to the onset of pain and degenerative changes in the given age group as compared to another age group (Hayes CW 2005).[22] On considering the KL Grading [Figure 9] of the study participants, the highest number of study participants were seen in Grade 2, i.e., 52.9% (n = 45), followed by Grade 3, i.e., 29.4% (n = 25), followed by Grade 1, i.e., 17.6% (n = 15). A similar percentage of the study participants was seen in the study done by R Sanyal et al. (2018),[23] where the majority of the patients had a radiological diagnosis of K-L grade II and III osteoarthritis.

Figure 7.

Gender Distribution of Study Participants- Group I contained males and females in proportion 20.9%: 79.1% while Group II contained males and females in proportion 28.6%: 71.4. Overall male–female proportion of the study was 24.7%: 75.3%. No significant difference was found in male–female proportion between Group I and Group II

Figure 8.

The study participants were divided into three age groups: 50–58 years, 59–66 years, and 67–74 years. Group I contained these age groups in the proportions 65.1%: 23.3%: 11.6%, while Group II contained the same age groups in the proportions 47.6%: 35.7%: 16.7%. No significant difference was found in the distribution of different age groups between Group I and Group II, indicating that the study participants were matched for age (P = 0.265)

Figure 9.

The study participants were categorized according to K–L grading. In Group I, grades I, II, and III were present in proportions of 7.0%, 62.8%, and 30.2% respectively. In Group II, these grades were present in proportions of 28.6%, 42.9%, and 28.6% respectively. A significant difference in K–L grading was observed between the groups (P = 0.027)

On making the comparison for NPRS score at baseline and 6 weeks the reduction in NPRS score was higher for group I PRP as compared to group II dextrose with P-value significant at <0.001. In comparison similar finding was seen in the study done by R Sanyal et al. (2018),[23] Raeissadat SA et al. (2020),[24] which could be attributed to the growth factors released by PRP, which is known to promote cell recruitment, proliferation, and angiogenesis resulting in a reduction in the critical regulators of the inflammatory process and a decrease in the expression of inflammatory enzymes (Van Buul et al. 2011).[25] On considering the parameter of LKI Pain at baseline and 6 weeks for PRP and Dextrose, it was found that in Group I, the mean ± SD reduced more at 6 weeks from 4.81 ± 1.55 to 2.44 ± 1.76 as compared to participants in Group II with 4.83 ± 1.17 at baseline to 6 weeks 3.64 ± 0.98. The findings were in correspondence with the study done by Distel LM and Best TM,[5] which could be attributed to the fact that the combined effects of PRP make it a potential option for the management of knee OA, especially as a primary analgesic agent (Meheux et al. 2016),[26] and also causes an increase in the proliferation of tenocytes, osteoblasts, and mesenchymal stem cells resulting in decreased pain levels (Ogino et al. 2006).[27] On the evaluation of the intergroup comparison of LKI- MDW, a similar finding was concluded in the study conducted by Chouhan DK et al. (2019).[28] The MDW score of both groups was not found to have dropped significantly; the reason for such a lesser reduction in the score could be attributed to the short span of follow-up from the baseline and the lesser number of interventions. On making the intergroup comparison of LKI-ADL for group I PRP the Mean ± SD score dropped from 4.66 ± 1.40 to 2.95 ± 1.35, whereas for group II Dextrose the Mean ± SD score dropped from 4.68 ± 1.40 to 3.65 ± 1.51 at baseline and 6 week, respectively. The drop in score was found to be higher for the PRP group as compared to the dextrose group with P-value significant at 0.027. This shows that considering the effect of platelet-rich plasma and 25% hypertonic dextrose prolotherapy in patients with osteoarthritis knee, significant improvement was seen in participants of both groups with a higher effect observed with PRP.

Conclusion

Osteoarthritis is the most common degenerative disease affecting the joints worldwide. It is also the most common cause of joint disability in India. The older age population is most affected and it is more common among the females. Different types of treatment are available for osteoarthritis. Henceforth, it could thus be concluded that significant improvement was seen in participants administered with both PRP and Dextrose with the higher effect being with PRP on considering the effect of platelet-rich plasma and 25% hypertonic dextrose prolotherapy in patients with osteoarthritis knee.

Limitations and recommendations

• 1)Owing to the short span of follow-up, the long-term effectiveness of the platelet-rich plasma and 25% hypertonic dextrose prolotherapy could not be assessed.
• 2)The outbreak of the COVID-19 pandemic during the study period, led to limited inclusion of study participants in each group. However, the data were sufficient enough to assess the inter and group differences over some time.
• 3)The affordability and cost of the intervention could differ because PRP needs specific kits like centrifuge machines and centrifuge vials, so the cost is higher than dextrose prolotherapy.

To make more inferences there is a need for studies with larger sample sizes, increased number of interventions, and long-term follow-up.

Abbreviations

ADL- Activities of Daily Living

K L - Kellgren and Lawrence grading system

LKI-P - Lequesne Knee Index-Pain

NPRS - Numeric pain rating scale

OA - Osteoarthritis

PMR - Physical Medicine and Rehabilitation

PRP - Platelet-Rich Plasma

SD - Standard Deviation

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.