|Year : 2016 | Volume
| Issue : 3 | Page : 185-191
Ultrasound-guided platelet-rich plasma infiltration: A stupendous treatment for chronic tendinopathy
Abhijeet Sahu1, Pradeep K Singh2, Sohael Khan1, Shraddha Singhania3, Mahendra Gudhe1, Gaurav Mundada1, Vasant Gawande1
1 Department of Orthopaedics, Jawaharlal Nehru Medical College, Wardha, India
2 Department of Orthopaedics (Spine), Hiranandani Hospital, Mumbai, Maharashtra, India
3 Department of Radiodiagnosis, Datta Meghe Institute of Medical Sciences, Wardha, India
|Date of Web Publication||28-Sep-2016|
C/O Dr. M. J. Khan, Shishu Hospital, Opp. Zilla Parishad, Sarai Ward, Chandrapur - 442 401, Maharashtra
Source of Support: None, Conflict of Interest: None
Background: Tendinopathy is a common and perplexing problem facing clinicians. It is the most common reason that patients seek medical attention for a musculoskeletal condition and accounts for approximately 30% of patient visits to general practitioners. Although originally considered an inflammatory problem, histopathologic analysis of tendinopathy has revealed evidence that this process is predominantly degenerative and is characterized by hypercellularity, vascular hyperplasia, and collagen disorganization. Since tendinopathy is primarily a degenerative condition, several new treatments have been developed in an attempt to stimulate tissue regeneration. One of these treatments is an injection of platelet-rich plasma (PRP). Materials and Methods: This is a prospective study conducted in the Department of Orthopaedics on outpatients having tendinopathies. These patients were managed with PRP infiltration at the tendinopathy site. Current proposed sample size in the study is sixty patients between the age of 21 and 65 years. The patients who are clinically diagnosed were given PRP at the tendinopathy after identifying the site under ultrasound guidance. Patients were assessed according to the visual analog scale (VAS) and Disabilities of the Arm, Shoulder, and Hand (DASH) score pre- and post-injection. Results: Patients in the fourth decade had major preponderance. Male gender was dominant with the problem of tendinopathies. Supraspinatus tendinopathy was most common among all tendinopathies. Comparison of VAS with each follow-up showed 22.5% decrease in 1 st week and 58.58% relief in 4 th week. After evaluation using DASH score, there was 7.23% improvement in 1 st week, 12.43% in 4 th week, and 57.63% in 24 th week. Conclusion: The current investigation represents clinically based outcome study to evaluate the effectiveness of treating tendinopathy with ultrasonography-guided PRP injection. There is reduced the risk of infection, better improvement regarding pain, restoration of mobility, and duration of time required for clinical improvement. None of these patients reported with the recurrence of symptoms when followed up after 6 months of treatment.
العلاج المذهل لأمراض الأوتار المزمن – بحقن البلازما الغنية بالصفائح الدموية الموجه بالموجات فوق الصوتية لمصل
خلفية البجث: أمراض الأوتار أمر شائع و محير للأطباء. ذلك هو السبب الأكثر شيوعا لمرضى الرعاية الطبية الذن يعانون من الاعتلالات االعضلية والعظام ويمثلون حوالي 30٪ من أسباب زيارة المرضى للأطباء العموميين. وعلى الرغم من أن مشكلة الاتهابات تعد أصل المشكلة، فقد كشف تحليل الأنسجة المريضة لأمراض الأوتار دليلا على أن هذه العملية هي في الغالب هرمية وتتميز بازدياد الأنسجة وعدد الخلايا و تمدد الأوعية الدموية، و عدم انتظام الكولاجين. وبما أن أمراض الأوتار هي حالة هرمية في المقام الأول فقد وضعت عدة علاجات جديدة في محاولة لتحفيز تجديد الأنسجة. واحد هذه العلاجات هو حقن البلازما الغنية بالصفائح الدموية (PRP). المواد والطريقة: هذه دراسة استطلاعية أجريت في قسم جراحة العظام في العيادات الخارجية على مرضى يعانون من أمراض االأوتار . وقد تم التحكم في أولئك االمرضى عن طريق حقنهم بالبلازما الغنية بالصفائح الدموية PRP في موقع مرض الأوتار الحالي وكان حجم العينة المقترحة في هذه الدراسة هو ستين مريضا تتراوح أعمارهم ما بين 21 و 65 عاما. أعطيت للمرضى بعد تشخيصهم سريريا البلازما الغنية بالصفائح الدموية PRP بعد تحديد الموقع تحت توجيه الموجات فوق الصوتية. وتم تقييم المرضى بالمقياس المماثل المرئي (VAS) ومعدل الإعاقة للذراع الذراع، الكتف، واليد (DASH)قبل الحقن و بعده. النتاثج: كان المرضى في العقد الرابع الغالبية العظمى و قد هيمن الرجال على مشكلة أمراض االأوتار والتهاب الأوتار فوق الشوكية وأظهرت مقارنة المقياس المماثل المرئي VAS مع كل متابعة انخفاض٪ 22.5 في الأسبوع الأول ونسبة شفاء 58.58٪ في الأسبوع الرابع. بعد التقييم باستخدام معدل الإصابة DASH، كان هناك تحسن بنسبة 7.23٪ في الأسبوع الأول، 12.43٪ في الأسبوع الرابع، و57.63٪ في الأسبوع الرابع والعشرين
الخلاصة: تمثل نتائج الدراسة حصيلة تستند سريريا لتقييم فعالية علاج التهاب الأوتار بالموجات الصوتية الموجهة لحقن البلازما الغنية بالصفائح الدموية PRP. هناك انخفاض خطر الإصابة، وتحسين أفضل فيما يتعلق بالألم ، واستعادة الحركة، ومدة الفترة الزمنية للتحسن السريري. لم يسجل فى أي من المرضي أعراض بعد المتابعة بعد 6 أشهر من العلاج.
Keywords: Platelet-rich plasma, tendinopathy, ultrasound
|How to cite this article:|
Sahu A, Singh PK, Khan S, Singhania S, Gudhe M, Mundada G, Gawande V. Ultrasound-guided platelet-rich plasma infiltration: A stupendous treatment for chronic tendinopathy. Saudi J Sports Med 2016;16:185-91
|How to cite this URL:|
Sahu A, Singh PK, Khan S, Singhania S, Gudhe M, Mundada G, Gawande V. Ultrasound-guided platelet-rich plasma infiltration: A stupendous treatment for chronic tendinopathy. Saudi J Sports Med [serial online] 2016 [cited 2022 Aug 13];16:185-91. Available from: https://www.sjosm.org/text.asp?2016/16/3/185/191334
| Introduction|| |
Platelet-rich plasma (PRP) injections are nowadays being used as an alternative for treating the tendinopathies, who have failed to be managed by conservative management. PRP comes with additional benefit and carries minimal risk. , PRP is created from an autologous whole blood sample through a platelet separation process, which results in an increased platelet concentration compared with the original whole blood sample.  It is theorized that when PRP is injected into an area of tendinopathy, the platelets release a multitude of growth factors and stimulate a healing response. 
Platelet-released supernatants resulted in a stimulation of cell proliferation in periosteal explants. Gel chromatographic analysis revealed the highest mitogenic activity of basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) factors that released from activated platelets. FGF is pleiotropic in its effects, and its clinical effectiveness may depend on other factors present at the implantation site. Like all growth factors in the classic sense, specific sequences of extracellular proteins may also have growth factor-like potential. There is an increasing awareness that structural proteins in the extracellular matrix can directly regulate cell activity in a growth factor-like manner. However, the mitogenic activity of platelet-released supernatants was decreased by anti-PDGF and anti-bFGF antibodies. This adverse reaction can be overcome using autologous platelet-released supernatants. Some study on equine subjects gave satisfactory results in chronic musculoskeletal inflammatory disorders.  A role for endogenously released growth factors including insulin-like growth factor-1, tissue growth factor-β (TGF), vascular endothelial growth factor, PDGF, and bFGF in tendon, and ligament healing is well documented.  They participate in each of inflammation, cell proliferation, and tissue remodeling. Autologous platelets would therefore provide an additional source of the above factors.
These results suggest that platelets have the potential to stimulate the mitogenic response of the periosteum, and mesenchymal cells thus can be helpful in tissue repairing. Again, dose, delivery vehicle, release kinetics, and clinical profile are important variables. Studies show that growth factors can be successfully used to treat musculoskeletal defects. In some country, only a limited number of factors are approved for use to treat musculoskeletal disorder; however, it is evident that these factors have potential far beyond their current approvals. These factors are underutilized in clinical practice when we have the overwhelmed number of patients hoping for the definite management of their pathology. Clinician working in a country where economic constrains limit the outcome of diseases may be convinced that half milliliter of patients own supernatant of platelet can be a treatment revolution for such minor pathology.
| Materials and methods|| |
This is a prospective study, which was carried in outpatient department in the Department of Orthopaedics with tendinopathies was included in the study. Sample Size was of sixty patients between 21 and 65 years of age, having tendinopathies.
This study has endeavored to evaluate the clinical effects of PRP on tendinopathy. This study was undertaken to characterize tendinopathy using ultrasonography (USG), to assess the correlation of age, sex, and occupation with the type of tendinopathy. To assess the correlation of occupation with the type of tendinopathy and to evaluate the pain score, functional outcome, and correlation between pain score and functional outcome pre- and post-injection.
Patients between 21 and 65 years of age were included who were diagnosed clinically as tendinopathy. Failed conservative treatment patients were also included in the study. Patients with platelet dysfunction syndrome, critical thrombocytopenia, septicemia, local infection at the site of the procedure, consistent use of nonsteroidal anti-inflammatory drugs within 48 h of procedure, corticosteroid injection at the treatment site within a month or use of systemic corticosteroid within 1 month, or platelet count <105/u were excluded from the study.
All the patients who were included in the study were given PRP by a single physician and an assistant to aid in preparation, maintenance of aseptic technique and a radiologist for identifying the site of pathology, and saving images on ultrasound.
| Observation and results|| |
The age-wise distribution shows third decade to have 10% of total patients, fourth decade to have 25%, fifth decade to have 41.67%, sixth decade to have 16.67%, and seventh decade to have 6.67%. Gender-wise distribution of patients shows 58.33% of males and 41.67% of females [Graph 1].
Distribution of patient according to diagnosis shows 50% of supraspinatus tendinopathy, 21.7% of lateral epicondylitis, 6.7% of medial epicondylitis, 15% of De Quervain's tenosynovitis, and 6.7% of trigger finger of all the patients included in the study [Table 1], [Graph 2].
A total of 6 patients in the third decade, 5 of supraspinatus tendinopathy and 1 of De Quervains tenosynovitis. Fifteen patients in the fourth decade, 10 of supraspinatus tendinopathy, 3 of lateral epicondylitis, 1 of De Quervain's tenosynovitis, and 1 of trigger finger. Twenty-five patients in the fifth decade, 6 of supraspinatus tendinopathy, 9 of lateral epicondylitis, 2 of medial epicondylitis, 5 of De Quervain's tenosynovitis, and 3 of trigger finger. Ten patients in the sixth decade, 6 of supraspinatus tendinopathy, 1 of lateral epicondylitis, 1 of medial epicondylitis, and 2 of De Quervain's tenosynovitis. Four patients in the seventh decade, 3 supraspinatus tendinopathy and 1 of medial epicondylitis [Graph 3], [Table 2].
Correlation of occupation with diagnosis shows supraspinatus tendinopathy in 16 laborers, 6 farmers, 4 homemakers, 2 others, and 1 businessman. Lateral epicondylitis was seen in 6 home makers, 3 laborers, 2 farmers, 1 businessman, and 1 in other. Medial epicondylitis was seen in 2 laborers, 1homemaker, and 1 farmer. De Quervain's tenosynovitis was seen in 4 housemakers, 2 farmers, 1 laborer, 1 businessman, and 1 in other group. Trigger finger was seen in 2 homemakers, 1 laborer, and 1 in other group.
Comparison of Disabilities of the Arm, Shoulder, and Hand (DASH) [Table 3] score pre- and post-operatively shows 7.23% mean 50.25 decrease in the 1 st week, 12.43% mean 50.25 decrease in the 4 th week, 28.92% mean 38.50 in the 12 th week, 57.63% mean 22.95 in the 24 th week [Table 4].
|Table 4: Comparison of Disability of Arm, Shoulder, and Hand score pre‑ and post‑injection|
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There was a positive correlation seen between visual analog scale (VAS) and DASH scoring preoperatively and at 24 th week [Table 3].
| Discussion|| |
Self-reported musculoskeletal diseases are highly prevalent and are estimated at between 2% and 65% (depending on survey design factors and the age of the study population).  The number of overuse injuries is not exactly known, but in sports medicine, they account for 30-50% of all injuries.  In general, for physical workers, the prevalence of musculoskeletal symptoms increases with duration of employment.  Age-adjusted logistic regression analyses have shown that people who have worked for 25-35 years are more likely to develop tendinopathy.  The majority of overuse tendon injuries occur in men.
In our study, maximum age group within which the patients were diagnosed were of the fourth decade. The mean age group was 45.56 ± 10.24 years. These patients were 58.33% of males and 41.67% of females. Our findings were supported by the study of Hamilton,  in which the age incidence figures show clearly the excess of cases of epicondylitis in the 35-54 years age group, and the mean age of incidence was 45 years.
The total incidence of supraspinatus tendinopathy was 48.3% highest in our study. In our study, the most common age group within which this tendinopathy was seen was 31-50 years, this was most commonly found in laborers (16) and farmers (6) who were mostly involved with repetitive overhead abduction activities and rather less common in homemakers (4), businessmen (1), and others (2). Male predominance was present as far as sex ratio of this tendinopathy was concerned with 21 males having this pathology compared to 8 females.
Chen et al.,  they suggested that the incidence of biceps pathology is directly proportional to the extent of rotator cuff disease in 41% of cases and may be primarily due to a combination of primary changes from impingement process and a secondary change after the loss of overlying cartilage by rotator cuff. Biceps tendinitis can develop gradually as a result of overuse, aging, or stress, or it can occur suddenly from injury. Individuals at risk for biceps tendinitis include those who perform frequent repetitive overhead motions such as laborers, carpenters, painters, and delivery or warehouse workers who repeatedly lift and carry heavy items. Activities of daily life that involve overhead lifting and/or pounding can also lead to an inflamed biceps tendon. Wolf; Warner and Warren , in suggested certain type of sports requiring repetitive use of the arm at or above the horizontal and high strains within the tendon during the declaration phase, such as the tennis serve, the volleyball hit, and javelin and ball throwing may produce overloading, inflammation, and degeneration in the rotator cuff tendons.
Lateral epicondylitis incidence in our study was reported to be a total of 21.7%. This pathology was seen in people above 40 years of age group. Lateral epicondylitis was seen in 6 females and 7 males. This was most commonly seen among homemakers (6), followed by laborers (2), and finally farmers (1). Correlation of this pathology being almost equal in both the sexes in our study supports the literature. Association of this being common in homemakers can be attributable since they are liable for various household activities which require excessive use of forearm supinator's and wrist extensors making them more prone for this pathology. Gruchow and Pelletier  reported the incidence of lateral epicondylitis varied from 31% to 41%. Lateral epicondylitis is perhaps one of the most common insertional tendinopathy of the human body. Ciccotti and Lombardo  stated that the cause of lateral epicondylitis is excessive, monotonous use of the wrist extensors, and forearm supinator's.
De Quervain's tenosynovitis incidence was found to be 15% in our study. Maximum incidence of this occurred in the fifth decade in our study. Seven females reported to have this pathology in our study compared to 2 males. The incidence was highest among homemakers (4), followed by farmers (2), and occurring equally among laborers, businessmen, and others (1 each).
Werner et al.  postulated that in physical workers the incidence of hand and wrist tendinopathies ranges from 4 to 56%. The risk is increased when there is a combination of high force, repetition, or exposure to vibration during repetitive work. Cumulative trauma to tendons, tenosynovitis, tendinopathy, De Quervain's syndrome, and paratendinopathy can occur as a result of repetitive motion about the wrist. Awkward posturing exacerbates this. Examples of this include ulnar deviation of the wrist with a fixed thumb, rapid finger flexion, grasping in radial deviation, violent pulling, wrenching grip, twisting with forearm pronation and supination, or pinch followed by quick pronation. Excessive flexion and extension of the digits against resistance and overuse of index finger with pistol-type air tools can cause trigger finger.
Cumulative trauma to tendons can occur as a result of repetitive motion about the wrist. Awkward posturing exacerbates this. Examples of this include ulnar deviation of the wrist with a fixed thumb, rapid finger flexion, grasping in radial deviation, violent pulling, wrenching grip, twisting with forearm pronation and supination, or pinch followed by quick pronation. The risk is increased when there is a combination of high force, repetition, or exposure to vibration during repetitive work.
Trigger finger incidence in our study was reported to be a total of 6.67%. Most common age group having this pathology was 41-50 years with three patients falling in this category. Two males and two females prevalence of trigger finger were reported. Two homemakers reported to have trigger finger 1 laborer and 1 included in the other group in our study.
Makkouk et al.  in the their article suggested, repetitive finger movements and local trauma are possibilities with such stress and degenerative forces also accounting for an increased incidence of trigger finger in the dominant hand.
Trigger finger occurs most commonly in the middle fifth to sixth decades of life and up to six times more frequently in women than men although the reasons for this age and sex predilection are not entirely clear.
Medial epicondylitis incidence in our study was reported to be a total of 6.67%. The age group within which this pathology was most evident was in the fifth decade. This was seen in three males and one female. Most commoly, it was seen among laborers (2), followed by housewive (1), and farmer (1). Ciccotti et al.  in their article suggest that there exists, however, a paucity of literature regarding medial epicondylitis, likely due to its infrequent incidence of only 9.8-20% of all epicondylitis diagnoses.
Although the syndrome has been identified in patients ranging from 12 to 80 years old, it predominantly occurs in the fourth and fifth decades. Male and female prevalence rates are reportedly equal. Seventy-five percent of patients are symptomatic in their dominant arms. The majority of the literature on epicondylitis suggest that the disorder's primary etiology is a repetitive stress or overuse of the flexor-pronator musculature. Medial epicondylitis, however, is not solely athletic in origin because it is also associated with occupations such as carpentry, plumbing, and meat cutting, all of which require repetitive forearm, wrist, and hand motions. Degenerative changes in the musculotendonous region of the medial epicondyle are the result of chronic repetitive concentric and eccentric contractile loading of the flexor-pronator group. Although repetitive overuse has been identified as the primary etiology, a single traumatic event, such as a direct blow or a sudden, extreme eccentric contraction, may result in the development of epicondylitis. Medial epicondylitis has been associated with activities involving repetitive forearm pronation and wrist flexion.
Comparison of the baseline VAS with each follow-up showed 22.55% decrease in the 1 st week, 58.58% relief in 4 th week, 54.90% relief in 12 th week, and 66.76% relief in 24 th week. These findings were found to be significant with other authors who compared the VAS scores. Mishra and Pavelko  8 weeks postinjection the PRP patients reported 60% improvement in VAS pain score. At 6 months postinjection, cases reported 81% improvement in their VAS pain score and at final follow-up patients reported 93% of reduction in their VAS pain score. Finnoff et al.  found the mean pain improvements of 58%. Ragab and Othman  in their study found the VAS to improve from 9.1 to 1.6. Mautner et al.,  patients perceived decrease in VAS was 75%. Gonsenseus et al.  evaluated the outcome of patients of patellar tendinopathy in 36 patients and found that the pain score by VAS improved significantly on comparison with its daily activities; however, there was no significant improvement on VASs.
On evaluating the functional outcome of the patient in our study using DASH scores, there was 7.23% improvement in the 1 st week, 12.43% in the 4 th week, 28.92% in the 12 th week, and 57.63% in the 24 th week. Ragab and Othman,  60% of patients had no functional limitations postinjection and 32% had minimal functional limitations. Two patients (8%) had moderate functional limitations postinjection.
Katana et al.  in their study found good improvement with good functional restitution in 56% of the respondents. This study does not take into account. The DASH scoring as used in our study; however, the functional status of the tendon in both the study was the same. We have used infiltration of only single injection of PRP in our study. PRP has also been found to recruit reparative cells.  This helps explain why a single PRP application can have a lasting effect on the healing process as concluded in this study. Through interaction with macrophages, PRP may control the inflammatory reaction and thus improve tissue healing and regeneration. It is clear from in vitro studies that PRP initially inhibits interleukin-1 (IL-1) production from macrophages and reduces their proliferation. By day 4, however, this inhibition turns to stimulation of IL-1 and macrophage division.  This initial suppression of macrophage activity may prevent the excessive early inflammation that can lead to dense scar tissue formation. It may further be possible for PRP to regenerate tissue phenotypically closer to normal tendon and muscle by stimulating quiescent stem cells.  Mautner et al.,  in their study, evaluated 60% of patients required/received only one injection, 30% required/received two injections, and 10% received/required three or more injections. We have used double-centrifugation method for the preparation of PRP in our methods. Various authors have also postulated regarding the preparation of PRP and have proposed their different methodology. Gonshor  described two-stage technique for processing PRP and revealed that the platelet concentration was three to five times the whole blood baseline, the concentration of the PDGF-AB was above 500%, and TGF-β1 was also >800%. Flow cytometry-measuring P-selection expression showed that the platelet remains quiescent throughout the process maintaining their integrity and visibility with no inadvertent activation. Anitua  has described the technique of single centrifugation where he obtained a 2-3 fold increase in platelet concentration from the baseline value.
| Conclusion|| |
Results suggest that this treatment may be an effective and safe treatment option for patients presenting with tendinopathy mostly in a variety of locations. There is reduced the risk of infection as the whole procedure of platelet separation is done under a closed system.
The patients showed better improvement regarding relief from pain, restoration of mobility, and duration of time required for clinical improvement. Patients do not require continuing anti-inflammatory medications. We can avoid surgeries in patients with chronic pain. None of the patients had reported with recurrence of symptoms on 6 months follow-up; hence, a single injection can be effective.
PRP can be immediately prepared at the point of care, which makes it simple and less expensive.
PRP procedure follows an excellent safety profile.
USG-guided injection technique has the advantage of giving the injection exactly at the site of pathology.
Studies have shown no effects of PRP on USG tendon
structure and neovascularization and hence, repeat USG on follow-up is not required for the evaluation of effectiveness of PRP and pain score in itself is a significant indicator.
Clinician working in a country where economic constrains limit the outcome of diseases may be convinced that half millimeter of patients own supernatant of platelet can be a treatment revolution for such minor pathology.
| References|| |
Järvinen M. Epidemiology of tendon injuries in sports. Clin Sports Med 1992;11:493-504.
Kraushaar B, Nirschl RP. Current concepts review: Tendinosis of the elbow (tennis elbow). Clinical features and findings of histological, immunohistochemical, and electron microscopy studies. J Bone Joint Surg Am 1999;81:259-78.
Eppley BL, Woodell JE, Higgins J. Platelet quantification and growth factor analysis from platelet-rich plasma: Implications for wound healing. Plast Reconstr Surg 2004;114:1502-8.
Sampson S, Gerhardt M, Mandelbaum B. Platelet rich plasma injection grafts for musculoskeletal injuries: A review. Curr Rev Musculoskelet Med 2008;1:165-74.
Maia L, de Souza MV, Ribeiro Junior JI, de Oliveira AC, Silveira Alves GE, Anjos Benjamin LD, et al
. Platelet-rich plasma in the treatment of induced tendinopathy in horses: Histologic evaluation. J Equine Vet Sci 2009;29:618-26.
Molloy T, Wang Y, Murrell G. The roles of growth factors in tendon and ligament healing. Sports Med 2003;33:381-94.
Forde MS, Punnett L, Wegman DH. Prevalence of musculoskeletal disorders in union ironworkers. J Occup Environ Hyg 2005;2:203-12.
Scott A, Ashe MC. Common tendinopathies in the upper and lower extremities. Curr Sports Med Rep 2006;5:233-41.
Hamilton PG. MRCGP: The prevalence of humeral epicondylitis: A survey in general practice. J R Coll Gen Pract 1986;36:464-5.
Chen H, Smith M, Shadmehr R. Effects of deep brain stimulation on adaptive control of reaching. Conf Proc IEEE Eng Med Biol Soc 2005;5:5445-8.
Wolf WB 3 rd
. Shoulder tendinoses. Clin Sports Med 1992;11:871-90.
Warner JJ, Warren RF. Consideration and management of rotator cuff tears in athletes. Ann Chir Gynaecol 1991;80:160-7.
Gruchow HW, Pelletier D. An epidemiologic study of tennis elbow. Incidence, recurrence, and effectiveness of prevention strategies. Am J Sports Med 1979;7:234-8.
Ciccotti MG, Lombardo SJ. Lateral and medial epicondylitis of the elbow. Operative Techniques in Upper Extremity Sports Injuries. St. Louis (MO): Mosby-Year Book. 1996:431-6.
Werner RA, Franzblau A, Gell N, Ulin SS, Armstrong TJ. A longitudinal study of industrial and clerical workers: Predictors of upper extremity tendonitis. J Occup Rehabil 2005;15:37-46.
Makkouk AH, Oetgen ME, Swigart CR, Dodds SD. Trigger finger: Etiology, evaluation, and treatment. Curr Rev Musculoskelet Med 2008;1:92-6.
Ciccotti MC, Schwartz MA, Ciccotti MG. Diagnosis and treatment of medial epicondylitis of the elbow. Clin Sports Med 2004;23:693-705, xi.
Mishra A, Pavelko T. Treatment of chronic elbow tendinosis with buffered platelet-rich plasma. Am J Sports Med 2006;34:1774-8.
Man D, Plosker H, Winland-Brown JE. The use of autologous platelet-rich plasma (platelet gel) and autologous platelet-poor plasma (fibrin glue) in cosmetic surgery. Plast Reconstr Surg 2001;107:229-37.
Ragab EM, Othman AM. Platelets rich plasma for treatment of chronic plantar fasciitis. Arch Orthop Trauma Surg 2012;132:1065-70.
Mautner K, Colberg RE, Malanga G, Borg-Stein JP, Harmon KG, Dharamsi AS, et al.
Outcomes after ultrasound-guided platelet-rich plasma injections for chronic tendinopathy: A multicenter, retrospective review. PM R 2013;5:169-75.
Gosens T, Den Oudsten BL, Fievez E, van ′t Spijker P, Fievez A. Pain and activity levels before and after platelet-rich plasma injection treatment of patellartendinopathy: A prospective cohort study and the influence of previous treatments. Int Orthop 2012;36:1941-6.
Katana B, Jaganjac A, Bojičicì S, Mačak-Hadžiomerovicì A, Pecar M, Kaljicì E, et al
. Effectiveness of physical treatment at De Quervain′s disease.J Health Sci 2012;2:80-84.
Woodall J Jr., Tucci M, Mishra A, Benghuzzi H. Cellular effects of platelet rich plasma: A study on HL-60 macrophage-like cells. Biomed Sci Instrum 2007;43:266-71.
Bi Y, Ehirchiou D, Kilts TM, Inkson CA, Embree MC, Sonoyama W, et al.
Identification of tendon stem/progenitor cells and the role of the extracellular matrix in their niche. Nat Med 2007;13:1219-27.
Gonshor A. Technique for producing platelet-rich plasma and platelet concentrate: Background and process. Int J Periodontics Restorative Dent 2002;22:547-57.
Anitua E. Plasma rich in growth factors: Preliminary results of use in the preparation of future sites for implants. Int J Oral Maxillofac Implants 1999;14:529-35.
[Table 1], [Table 2], [Table 3], [Table 4]