• Users Online: 73
  • Print this page
  • Email this page


 
 Table of Contents  
ORIGINAL ARTICLES
Year : 2022  |  Volume : 37  |  Issue : 1  |  Page : 6-12

A randomized controlled trial between autologous platelet-rich plasma injection and corticosteroid injection in the treatment of plantar fasciitis


1 Department of Orthopaedics, Ruby Hall Clinic, Pune, Maharashtra, India
2 Department of Orthopaedics, Institute of Medical Sciences—Banaras Hindu University, Varanasi, UP, India
3 Department of Orthopaedics, RNT Medical College & MB Govt. Hospital, Udaipur, Rajasthan, India
4 Department of Orthopaedics, Shanti Ved Institute of Medical Sciences, Agra, UP, India
5 Department of Ophthalmology, RNT Medical College & MB Govt. Hospital, Udaipur, Rajasthan, India
6 Department of Skin and VD, Pacific Medical College and Hospital, Udaipur, Rajasthan, India

Date of Submission13-Jan-2022
Date of Acceptance12-Apr-2022
Date of Web Publication13-May-2022

Correspondence Address:
Saumya Agarwal
16 D, Old Fatehpura, Near Seva Mandir, Udaipur, Rajasthan 313001
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jbjd.jbjd_1_22

Rights and Permissions
  Abstract 

Background: Plantar fasciitis is the most common cause of chronic pain beneath the heel in adults, which may cause significant discomfort and disability. Local corticosteroid injections are a popular method of treating the condition but only seem to be useful in the short term and only to a small degree. Autologous platelet-rich plasma (PRP) is rich in growth factor, which stimulates reparative process unlike corticosteroids. Materials and Methods: A total of 30 patients were allocated in each group. Group A consisted of patients who received single 2 ml local corticosteroid injection, that is 80 mg methylprednisolone acetate, and group B consisted of patients who received single 3 cc autologous PRP injection locally. Results: The postinjection mean Foot and Ankle Ability Measure (FAAM) score was significantly higher at 4 weeks, 8 weeks, and 12 weeks in the steroid group as compared to that in the PRP group, but at 24 weeks, the mean FAAM score was significantly higher in the PRP group as compared to that in the steroid group. This shows that the maximum effect of PRP on the FAAM score was at 24 weeks, whereas in the steroid group, it was at 12 weeks. Also the maximum effect of PRP on Visual Analog Scale was at 24 weeks, whereas in the steroid group, it was at 12 weeks. There was 39.21% reduction in mean plantar fascia thickness in the steroid group and 43.27% reduction in the PRP group. Conclusion: Autologous PRP therapy is better than local corticosteroid injection in the long-term effect.

Keywords: Calcaneum, centrifugation, corticosteroid, heel, plantar fascia, platelet-rich plasma


How to cite this article:
Varshney P, Verma AK, Agarwal S, Prakash S, Garg P, Agrawal P. A randomized controlled trial between autologous platelet-rich plasma injection and corticosteroid injection in the treatment of plantar fasciitis. J Bone Joint Dis 2022;37:6-12

How to cite this URL:
Varshney P, Verma AK, Agarwal S, Prakash S, Garg P, Agrawal P. A randomized controlled trial between autologous platelet-rich plasma injection and corticosteroid injection in the treatment of plantar fasciitis. J Bone Joint Dis [serial online] 2022 [cited 2022 Nov 27];37:6-12. Available from: http://www.jbjd.in/text.asp?2022/37/1/6/345159




  Introduction Top


Plantar fasciitis (PF) is the widely accepted most common foot condition treated by healthcare providers[1] and accounts for 15% of all foot disorders,[2] and is the most common cause of heel pain with more than 10% of the population suffering from it in their lifetime.[3] PF accounts for 7–14% of all sporting injuries[4] and is an especially common injury in runners and jogger athletes affecting as many as 25% of athletes.[5] Also known as the painful heel syndrome, it occurs in both males and females with a higher predominance in young male athletes and middle-aged obese females.[6] The etiology is poorly understood and unknown in approximately 85% of cases[7] and probably multifactorial, which includes chronic inflammation, degeneration and microtrauma of the plantar fascia, overuse syndrome, entrapment of lateral plantar nerve, heel pad atrophy, and seronegative arthritis-induced inflammation.[8]

Various methods have been advocated for treating PF, including rest, non-steroidal anti-inflammatory drugs (NSAIDs), night splints, foot orthosis, stretching protocols, and extracorporeal shock wave therapy (ESWT). Local corticosteroid injection at the site significantly reduces plantar fascia thickness within 2 weeks to 1 month. Cochrane review shows that local corticosteroid injection therapy has short-term benefit only and treatment effect lasts for not more than 6 months. Complications of palpation-guided steroid injection are plantar fascial rupture, fat pad atrophy, calcaneal osteomyelitis, and lateral plantar nerve injury secondary to injection. However, these complications have not been reported following ultrasonographic-guided injections.[9]

Platelet-rich plasma (PRP) is promoted as an ideal autologous biological blood-derived product, which can be exogenously applied to various tissues where it releases high concentrations of platelet-derived growth factors that enhance wound healing, tendon healing, and bone healing. In addition to this, PRP possesses antimicrobial properties that may contribute to the prevention of infections.[10] Injection of PRP at the attachment of the fascia to the os calcis might induce a healing response. Autologous PRP is rich in growth factor, which stimulates reparative process unlike corticosteroids. Studies have revealed significant relief of pain and improvement of function, which is comparable to the effect of corticosteroids.[11] The purpose of this study was to assess the role and efficacy of autologous PRP injection in the treatment of PF and compare it with corticosteroid injection.


  Materials and Methods Top


A randomized, comparative type of study was conducted in the Department of Orthopaedics of Ruby Hall Clinic, Pune, during the period of November 2018 to October 2021. The patients came to Outdoor Department with pain at the plantar medial heel region. A total of 30 patients were allocated in each group. Group A consisted of patients who received single 2 ml local corticosteroid injection that is 80 mg methylprednisolone acetate and group B consisted of patients who received single 3 cc autologous PRP injection locally.

Patients in the age group of 18–60 years presenting with complaints of heel pain, worse with rising in morning and/or after periods of sitting or lying that presented for 4 weeks or more and whose local examination revealed maximal tenderness at the attachment of the plantar fascia on the medial tubercle of the calcaneus, patients willing to participate in the study, patients willing to forgo any other concomitant conservative treatment modality such as NSAIDs and orthotic devices were included in the study. Patient who underwent surgery for plantar fasciitis, patients with neuropathic symptoms (radiculopathy, tarsal tunnel syndrome, tarsi sinus syndrome), Achilles tendon pathology, patient with complex regional pain syndrome, systemic diseases like rheumatoid arthritis, diabetes mellitus, local or systemic infection, peripheral vascular diseases, metabolic disease such as gout, clotting disorder, anticoagulation therapy, pregnant or breastfeeding female patients, dysfunction of the knee, ankle, or foot, work related or compensable injury, previous treatment with corticosteroid injection in the last 6 months or NSAIDs treatment within the last 7 days were excluded from the study. Informed written consent was taken from every patient. Patient information and history were gathered, and clinical evaluation was done along with the ultrasound (US) evaluation of plantar fascia thickness of both foot. Diagnosis was made on clinical and radiological basis. Initially, all the patients were treated with contrast bath foot stretching exercise and silicon heel pad for 4 weeks. The patients who were not benefited with the initial treatment were included in our study. Institutional ethical committee clearance was obtained.

Platelet-rich plasma preparation method

In all, 20 ml of a patient’s own venous blood was collected via blood draw, maintaining the sterile technique, with a syringe and then mixed with 2 ml of acid-citrate-dextrose (anticoagulant). This was then centrifuged at 3000 rpm for 15 min. The blood was then separated into platelet-poor plasma and PRP. The platelet-poor plasma was extracted and discarded. After one more shaking procedure, PRP was withdrawn. The resulting platelet concentrate contained approximately six to eight times the concentration of platelets when compared to the baseline whole blood.

Injection technique

The procedure was done on an outpatient basis and with complete aseptic conditions. The site of maximum tenderness was premarked with a sterile marker. Under sterile conditions, patients in group B received a 3 cc PRP injection (consisting of their own plasma) into the origin of the plantar fascia and the site of maximum tenderness [Figure 1]. About 2 cc of 2% lidocaine was infiltrated prior to the injection. A peppering technique spreading in a clockwise manner was used to achieve a more expansive zone of delivery, with a single skin portal and four to five passes through the fascia itself. Those in group A received 2 ml of methylprednisolone with 2 ml of 2% lignocaine locally at the most tender point. The patients were monitored for 20 min for adverse reactions and then sent home with instructions to limit their use of the feet for approximately 48 h and use opioid for pain. The use of nonsteroidal medication was prohibited. After 48 h, the patients were given a standardized stretching protocol to follow for 2 weeks and a full strengthening program was initiated at this level. After the procedure at 4 weeks, the patients were allowed to proceed with normal sporting or recreational activities as tolerated.
Figure 1: Clinical evaluation of PF, preparation of PRP, and infiltrating of PRP injection in a patient suffering from PF

Click here to view


Ultrasonography evaluation of plantar fascia

A diagnostic US machine with a 4 cm wide transducer head and 8 MHz probe was used. The patients were made to sit with their feet over the edge of the table and were allowed to see the examination. The examination consisted of applying ultrasonic gel to the transducer and then to the patients’ skin. The foot was made to relax in a semi-flexed position. US imaging of the plantar fascia consisted of the real-time scanning and obtaining the longitudinal sonograms. The thickness of plantar fascia was measured at the thickest portion from the base of the medial calcaneal tubercle of the affected side where a bright echogenic line was easily visible. A perpendicular measurement was then taken to the top of the image of plantar fascia where the most inferior border of the plantar fascia was discernable from fat. Plantar fascia thickness was measured for both heels before treatment and 6 months after treatment and was then compared. Plantar fascia thickness of more than 4 mm was considered abnormal. We followed up patients at 2 weeks, 4 weeks, 8 weeks, 12 weeks, and after 24 weeks. We used Visual Analog Scale (VAS) and Foot and Ankle Ability Measure (FAAM) for assessment of pain relief in both the groups. Those patients who did not respond to both the treatments at 6 months were taken as treatment failure.

Statistical analysis

The sample size was determined by using the mean difference of PRP and steroid groups. The reference literature has shown mean difference as 2.10 and expected standard deviation (SD) as 4.1092. The intergroup statistical comparison of distribution of categorical variables was tested using the chi-square test or Fisher’s exact probability test. The intergroup statistical comparison of means of continuous variables was done using the independent samples t-test. The intragroup comparison of means of continuous variables was done using repeated measures analysis of variance and paired t-test. In the entire study, the P values less than .05 were considered to be statistically significant. The entire data were statistically analyzed using Statistical Package for Social Sciences (SPSS version 21.0; IBM Corporation, Armonk, New York, USA) for MS Windows.[12]


  Results Top


The mean ± SD of age of cases studied in Steroid group A and PRP group B was 40.90 ± 9.24 years and 42.57 ± 10.47 years, respectively. The minimum–maximum age range in Steroid group A and PRP group B was 27–58 years and 20–60 years, respectively (P value > .05). Of 30 cases studied in Steroid group A, 13 (43.3%) were males and 17 (56.7%) were females, and out of 30 cases studied in PRP group B, 12 (40.0%) were males and 18 (60.0%) were females. The mean ± SD of body mass index (BMI) of cases studied in group A and group B was 23.10 ± 1.37 kg/m2 and 22.57 ± 1.62 kg/m2, respectively. The minimum–maximum BMI range in group A and group B was 19.30–24.80 kg/m2 and 19.30–24.70 kg/m2, respectively (P value > .05). Of 30 cases studied in group A, 16 (53.3%) had right side and 14 (46.7%) had left side involved, and of 30 cases studied in group B, 15 (50.0%) had right side and 15 (50.0%) had left side involved (P value > .05).

Preinjection characteristics between steroid group A and PRP group B are given in [Table 1]. We have seen that within group comparison for steroid group A, the results of mean FAAM score are statistically significant. The postinjection mean FAAM score increased from preinjection mean FAAM score continuously at 4 weeks, 8 weeks, and up to 12 weeks. However, at the end of 24 weeks, there was a fall in the mean FAAM score when compared to the mean FAAM score at 12 weeks. For within group comparison in PRP group B, the results of the mean FAAM score were statistically significant (P ≤ .05). The postinjection mean FAAM score increased from the preinjection mean FAAM score continuously at 4 weeks, 8 weeks, 12 weeks, and up to 24 weeks. The postinjection mean FAAM score was statistically significant in comparison with the preinjection mean FAAM score at all durations. When both treatment methods were compared, then it was observed that these two methods differed significantly in results. The postinjection mean FAAM score was significantly higher at 4 weeks, 8 weeks, and 12 weeks in steroid group A as compared to that in PRP group B, but at 24 weeks, the mean FAAM score was significantly higher in PRP group B as compared to that in steroid group A. This shows that the maximum effect of PRP on FAAM score was at 24 weeks, whereas in the steroid group, it was at 12 weeks [Table 2].
Table 1: Preinjection characteristics between PRP and steroid group

Click here to view
Table 2: Intergroup and intragroup comparison of mean FSCR score

Click here to view


We have seen that within group comparison for steroid group A, the results of mean VAS score were statistically significant. The postinjection mean VAS score decreased from the preinjection mean VAS score continuously at 4 weeks, 8 weeks, and up to 12 weeks. However, at the end of 24 weeks, there was a rise in the mean VAS score when compared to the score at 12 weeks. For within group comparison in PRP group B, the results of mean VAS score were statistically significant (P ≤ .05). The postinjection mean VAS score decreased from the preinjection mean VAS score continuously at 4 weeks, 8 weeks, 12 weeks, and up to 24 weeks. The postinjection mean VAS score was statistically significant in comparison with the preinjection mean VAS score at all durations. When both treatment methods were compared, then it was observed that these two methods differed significantly in results. The postinjection mean VAS score was significantly lower at 4 weeks, 8 weeks, and 12 weeks in steroid group A as compared to that in PRP group B, but at 24 weeks, the mean VAS score was significantly lower in PRP group B as compared to that in steroid group A. This shows that the maximum effect of PRP on VAS was at 24 weeks, whereas in steroid group A, it was at 12 weeks [Table 3].
Table 3: Intergroup comparison of mean VSCR score

Click here to view


There was 39.21% reduction in mean plantar fascia thickness in steroid group A and 43.27% reduction in PRP group B [Table 4]. One patient in each group (3.3%) had increase in postinjection plantar fascia thickness. Of 30 cases studied in steroid group A, one (3.3%) had failure. Of 30 cases studied in group B, none had failure.
Table 4: Intergroup and intragroup comparison of mean plantar fascia thickness

Click here to view



  Discussion Top


Chronic heel pain has been a difficult condition to treat for orthopedic surgeons. Traditionally, it has been treated by different modalities such as physiotherapy, use of soft heel footwear and local corticosteroid injections. It is quite well known that pain does not subside quickly but can persist for several weeks and results in significant disability. PRP injection has now become a choice as a treatment alternative for many musculoskeletal conditions. Therefore, we decided to do study on PRP to evaluate its effect and compare it with steroid.

The method of PRP preparation is based on studies conducted by Mazzocca et al.[13] who concluded that the platelet high spin method results in higher number of growth factors and platelets in the sample. The technique of PRP injection (peppering) was based on the studies performed by Scioli,[14] who found this method to be very effective.

Smith et al.[15] concluded that the FAAM score is the most extensively validated foot and ankle outcome instrument available, and the score is sensitive to overall health status and comorbidities. That is why we took FAAM scoring as one of our tools for evaluating functional outcome of foot in the postinjection period. In our study, the postinjection mean FAAM score was statistically significant in comparison with the preinjection mean FAAM score at all durations. The postinjection mean FAAM score was significantly higher at 4 weeks, 8 weeks, and 12 weeks in the steroid group as compared to that in PRP group B, but at 24 weeks, the mean FAAM score was significantly higher in PRP group B as compared to that in the steroid group.

Direct imaging of the PF is possible with MRI and US, and these methods have revealed that PF is thicker in patients with PF than in those without PF. Therefore, the changes in the thickness of the fascia after interventions in patients with heel pain are measurable with imaging techniques. The advantages of US as compared with MRI are that it is noninvasive, cost-effective approach that is also well tolerated by patients, and appropriate for serial follow-up. So we used ultrasonic evaluation of plantar fascia thickness as another tool for follow-up of our patients.[16]

Gould et al.[17] concluded that VAS is an effective tool and widely used due to its simplicity and adaptability to a broad range of populations and settings. In both the groups, there has been a significant reduction in postinjection mean VAS score from the preinjection mean VAS score over the course of study.

Earlier Lee and Ahmad[18] conducted prospective, randomized, controlled study of 64 patients for 6 months by comparing PRP and corticosteroid injection. The authors found that there is a significant reduction in VAS score for both the groups over a time. At 6 weeks and 3 months, the corticosteroid group had significantly lower VAS score than the PRP group, but the difference was not found out to be significant at 6 months. However, in our study, we found a significant reduction in the mean VAS score at 4 weeks, 8 weeks, and 3 months in the corticosteroid group, whereas at 6 months, there was significant reduction in the VAS score in the PRP group compared to that in the corticosteroid group.

A study performed by Aksahin et al.[19] compared the effects of corticosteroid injections and PRP injections to treat PF. A total of 60 patients were included who did not respond to conservative treatment for at least 3 months prior to either injection. The patients were placed into two groups of 30 patients each and were treated with a corticosteroid injection and a PRP injection, respectively. No significant difference in pain or patient satisfaction was found, thus demonstrating that PRP injections are equally effective as corticosteroid injections.

In a study conducted by Tiwari and Bhargava,[20] the cortisone group had a pretreatment mean VAS score of 8.5, which initially improved to 1.1 at 12 weeks post treatment, further increased to 4.9 at 26 weeks, and then continuously increased to near baseline levels of 8.4 at 52 weeks. In contrast, the PRP group started with an average pretreatment 8.6 score, which decreased to 3.4 at 12 weeks and went on declining to 1.2 at 26 weeks and 0.3 at 52 weeks. Naik et al.[21] concluded that in 92 patients who had undergone PRP injection, after 12 weeks, more than 60 patients showed great improvement in pain with their VAS score of pain being below 7; hence, it is good and effective in the treatment of PF, along with being a simple and safe procedure.

In this study, the reduction of plantar fascia thickness measured by US in both groups is statistically significant post treatment after 24 weeks. Although, the reduction in the thickness was more in the PRP group (43.27%) than in the steroid (39.21%) group, yet it did not reach a significant value. This study outlines that both injecting steroid and PRP are effective and safe modalities in the treatment of PF. The data suggest that steroid injection is better in the short-term period, but in long-term follow-up, PRP therapy is better than steroid (P < .05). The limitations of this study are shorter duration of follow-up and less number of sample size. Also we did not evaluate the platelet concentrate or the contained growth factors in our PRP solution.


  Conclusion Top


We conclude that PRP infiltration is an excellent method for long-term follow-up in PF patients, and further study can be done with more number of patients and longer duration of follow-up. Decrease in plantar fascia thickness evokes further research in this field.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his names and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Authors’ contribution

PV analyzed and interpreted the data. SA analyzed and was a major contributor in writing the manuscript. AKV and SP contributed and approved the final manuscript. PG and PA helped in understanding the concept related with PRP and its mechanism of action.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
McPoil TG, Martin RL, Cornwall MW, Wukich DK, Irrgang JJ, Godges JJ. Heel pain–plantar fasciitis: Clinical practice guidelines linked to the international classification of function, disability, and health from the orthopaedic section of the American Physical Therapy Association. J Orthop Sports Phys Ther 2008;38:A1-18.  Back to cited text no. 1
    
2.
Sorrentino F, Iovane A, Vetro A, Vaccari A, Mantia R, Midiri M. Role of high-resolution ultrasound in guiding treatment of idiopathic plantar fasciitis with minimally invasive techniques. La Radiologia Medica 2008;113:486-95.  Back to cited text no. 2
    
3.
Puttaswamaiah R, Chandran P. Degenerative plantar fasciitis: A review of current concepts. The Foot 2007;17:3-9.  Back to cited text no. 3
    
4.
Batt ME, Tanji JL. Management options for plantar fasciitis. Phys Sportsmed 1995;23:76-86.  Back to cited text no. 4
    
5.
Clement DB, Taunton JE, Smart GW, McNicol KL. A survey of overuse running injuries. Phys Sportsmed 1981;9:47-58.  Back to cited text no. 5
    
6.
Barrett SL, O’Malley R. Plantar fasciitis and other causes of heel pain. Am Fam Physician 1999;59:2200-6.  Back to cited text no. 6
    
7.
Roxas M. Plantar fasciitis: Diagnosis and therapeutic considerations. Altern Med Rev 2005;10:83-93.  Back to cited text no. 7
    
8.
Lai T-W, Ma H-L, Lee M-S, Chen P-M, Ku M-C. Ultrasonography and clinical outcome comparison of extracorporeal shock wave therapy and corticosteroid injections for chronic plantar fasciitis: A randomized controlled trial. J Musculoskelet Neuronal Interact 2018;18:47-54.  Back to cited text no. 8
    
9.
Karls SL, Snyder KR, Neibert PJ. Effectiveness of corticosteroid injections in the treatment of plantar fasciitis. J Sport Rehabil 2016;25:202-7.  Back to cited text no. 9
    
10.
Acevedo JI, Beskin JL. Complications of plantar fascia rupture associated with corticosteroid injection. Foot Ankle Int 1998;19:91-7.  Back to cited text no. 10
    
11.
Jain K, Murphy PN, Clough TM. Platelet rich plasma versus corticosteroid injection for plantar fasciitis: A comparative study. Foot (Edinb) 2015;25:235-7.  Back to cited text no. 11
    
12.
Rosner B. Fundamentals of Biostatistics. 5th ed. Duxbury; 2000. p. 80-240.  Back to cited text no. 12
    
13.
Mazzocca AD, McCarthy MBR, Chowaniec DM, Cote MP, Romeo AA, et al Platelet-rich plasma differs according to preparation method and human variability. J Bone Joint Surg Am2012;94:308-16.  Back to cited text no. 13
    
14.
Scioli MW. Platelet-rich plasma injection for proximal plantar fasciitis. Techniques in Foot & Ankle Surgery 2011;10:7-10.  Back to cited text no. 14
    
15.
Smith MV, Klein SE, Clohisy JC, Baca GR, Brophy RH, Wright RW. Lower extremity-specific measures of disability and outcomes in orthopaedic surgery. J Bone Joint Surg Am 2012;94:468-77.  Back to cited text no. 15
    
16.
Wu CH, Chang KV, Mio S, Chen WS, Wang TG. Sonoelastography of the plantar fascia. Radiology 2011;259:502-7.  Back to cited text no. 16
    
17.
Gould D, Kelly D, Goldstone L, Gammon J. Examining the validity of pressure ulcer risk assessment scales: Developing and using illustrated patient simulations to collect the data. J Clin Nurs 2001;10:697-706.  Back to cited text no. 17
    
18.
Lee TG, Ahmad TS. Intralesional autologous blood injection compared to corticosteroid injection for treatment of chronic plantar fasciitis. A prospective, randomized, controlled trial. Foot Ankle Int 2007;28:984-90.  Back to cited text no. 18
    
19.
Akşahin E, Doğruyol D, Yüksel HY, Hapa O, Doğan O, Celebi L, et al The comparison of the effect of corticosteroids and platelet-rich plasma (PRP) for the treatment of plantar fasciitis. Arch Orthop Trauma Surg 2012;132:781-5.  Back to cited text no. 19
    
20.
Tiwari M, Bhargava R. Platelet rich plasma therapy: A comparative effective therapy with promising results in plantar fasciitis. J Clin Orthop Trauma 2013;4:31-5.  Back to cited text no. 20
    
21.
Naik S, Agarwal S, Prakash S, Bhandari R, Agrawal P. Autologous PRP injection: A safe solution for plantar fasciitis. Journal of Arthroscopy and Joint Surgery 2021;8:253-5.  Back to cited text no. 21
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
Conclusion
References
Article Figures
Article Tables

 Article Access Statistics
    Viewed924    
    Printed76    
    Emailed0    
    PDF Downloaded79    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]