|
| Study (yr) | Intervention treatment (per group) | Study type | Number of subjects (total/study group; sex) | Subject characteristic (age; symptoms’ duration) | Previous therapy | Concurrent treatment | Follow-up | Outcome measures | Results | Authors’ conclusion |
|
Vetrano
et al. (2013)
[23] | G1: 2x USG PRP (2 mL) injections every 1 wk
G2: 3 sessions of focused ESWT (2.400 impulses at 0.17–0.25 mJ/mm2 per session) | RCT | G1: 23; 20 M/3 F
G2: 23; 17 M/6 F | G1:
26.9 ± 9.1 yr; mean 18.9 mo
G2:
26.8 ± 8.5 yr; mean 17.6 mo | Various treatments without any success | G1, G2: standardized stretching, muscle strengthening protocol; gradual return to sports activities (after 4 wk) | 2 mo; 6 mo; 12 mo | VISA-P, VAS, modified Blanzina scale | G1 showed significantly better improvement than the G2 in VISA-P, VAS scores (6, 12 mo FU) and in modified Blanzina scale score (12 mo FU) | Therapeutic injections of PRP lead to better midterm clinical results compared with focused ESWT in the treatment of jumper’s knee in athletes |
|
Dragoo
et al. (2014)
[26] | G1: USG PRP (6 mL) + 0.25% bupivacaine (3 mL) + 1 : 100,000 epinephrine injections; 10x MP
G2: USG 0.25% bupivacaine (3 mL) + 1 : 100,000 epinephrine injections; 10x MP | RCT | G1:
9; 8 M/1 F
G2:
12; 12 M/0 F | G1: 28 ± 8 yr
G2: 40 ± 14 yr | Various treatments without any success | G1, G2: physical therapy twice per week; standardized additional exercises at home | 3 wk; 6 wk; 9 wk; 12 wk; ≥6 mo | VISA-P; Tegner; Lysholm; VAS; SF-12 | G1 showed significantly better improvement than the G2 at 12 wk (P = 0.02), but the difference between two groups was not significant at ≥26 wk (P = 0.66) | PRP injection accelerates the recovery from patellar tendinopathy relative to USG dry needling, but the apparent benefit of PRP dissipates over time |
|
Volpi
et al. (2007)
[21] | G1: 0.5 mL of local anaesthetic (lidocaine) injected; 1x USG (3 mL) PRP injected
G2: no control group | Non-RCT; prospective cohort study | 8/8; 7 M/1 F
(3 bilateral) | 26.6 (21–41) yr; at least 1 yr | Various treatments without any success | Rest, walking (1st 7 d); stretching exercises, exercise bike, walking in water, light swim (7–21 d); eccentric quadriceps training, concentric strengthening (after 5 wk); muscular strengthening, jogging (after 7 wk); normal sport activities (after 12 wk) | 7 d;
30 d; 60 d; 120 d | VISA-P; MRI | Statistically significant improvement in VISA-P score for
7 out of 8 patients treated | Valid therapeutic option (PRP) |
|
Kon et al.
(2009) [4] | G1: PRP injections (3x) were administered every 15 d without USG; before the injection, 10% of CaCl2 was added to the PRP unit (5 mL with ca. 6.8 million platelets) to activate platelets; 4–6x MP
G2: no control group | Non-RCT; prospective cohort study | 20/20; 20 M
(7 bilateral) | 25.5 (18–47) yr; 20.7 (3–60) mo | Various treatments without any success | Rest (between 1st and 2nd injection); stretching exercises and mild activities (after 2nd injection); stretching exercises and mild activities (after 3rd injection); normal sport activities
(after 1 mo) | ET; 6 mo | Tegner; EQ-VAS; SF-36 questionnaires | Statistically significant improvements in all scores | Safe application, aiding the regeneration of tissue with low healing potential; long-term RCT needed |
|
Filardo
et al.
(2010) [22] | G1: PRP injections (3x) were administered every 15 d without USG; before the injection, 10% of CaCl2 was added to the PRP unit (5 mL with ca. 6.5 million platelets) to activate platelets; 4–6x MP
G2: no injection | Non-RCT | 31/15; 31 M
(5 bilateral) | G1:
28.8 ± 8.5 yr; 24.1 ± 19.9 mo
G2:
25.5 ± 9.2 yr; 8.4 ± 4.1 mo | G1: various treatments without any success
G2: without treatment (at least 2 mo), primarily physiotherapy protocol only | Rest (between 1st and 2nd injection); stretching exercises and mild activities (after 2nd injection); stretching exercises and mild activities (after 3rd injection); normal sport activities
(after 1 mo) | ET; 6 mo | Tegner; EQ-VAS; pain level | Statistically significant improvements in all scores | PRP can be useful for the treatment of chronic patellar tendinopathy, even in difficult cases with refractory tendinopathy (only physiotherapy approach had failed) |
|
Gosens
et al.
(2012) [27] | G1 and G2: 1 mL of PRP + bupivacaine HCl 0.5% + epinephrine injection
(1st injection); remaining PRP + bupivacaine HCl 0.5% + epinephrine (ca. 4 mL) injected (2nd injection) | Non-RCT; prospective cohort study | 36/36; 23 M/13 F | 30.9 ± 12.6 yr; 40.3 ± 28.4 mo | G1: 14, various treatments without any success
G2: 22, without treatment | Rest (1st 24 hr); standardized stretching protocol (after 24 hr–2 wk); eccentric muscle and tendon-strengthening program (after stretching); normal sport activities
(after 1 mo) | Mean 18.4 mo (after PRP treatment) | VISA-P; VAS | VAS scales: improved (G1, G2)
VISA-P: less healing potential (G1); improved (G2)
Overtime follow-up: both groups showed a clinically significant improvement | Statistically significant improvement |
|
Ferrero
et al.
(2012) [28] | G1 and G2: local anesthesia (4 mL of 2% mepivacaine) injected; 2x PRP (6 mL) injected at a mean distance of
3 ± 0.52 wk with USG | Non-RCT | G1 (patellar tendon): 24; 14 M/10 F
(4 bilateral)
G2 (Achilles tendon): 24; 16 M/8 F
(6 bilateral) | G1: 37.4 (21–56) yr; at least 3 mo
G2: 38.6 (20–61) yr; at least 3 mo | Various treatments without any success | Minimize physical activity (after 48 hr); physiokinesitherapy gradual return to sports activities (after 2 wk) | 20 d; 6 mo | VISA-P; VISA-A; US | Nonsignificant improvement
(20 d FU); intratendinous vascularity increased both
20 d FU and 6 mo FU; significant improvement (6 mo FU) | Statistically significant and lasting improvement of clinical symptoms; PRP injection leads to recovery of the tendon matrix potentially helping to prevent degenerative lesions |
|
Filardo
et al.
(2013) [29] | G1: 3x USG PRP injections were administered every 14 d; before the injection, 10% of CaCl2 was added to the PRP unit (5 mL) to activate platelets
G2: no control group | Non-RCT | 43/43; 42 M/1 F (11 bilateral) | 30.6 ± 11.7 yr; ≥3 mo | Various treatments without any success | Rest (between 1st and 2nd injection); eccentric exercises (after 2nd injection-12 wk) | ET; 2 mo; 6 mo; up to 48.6 ± 8.1 mo | Blanzina; VISA-P; EQ-VAS;
Tegner; US (26 tendons) | Good and stable results over time; significantly poorer results with a
longer history of symptoms; poor results with bilateral lesions; no correlation between US and clinical findings | Good overall results for the treatment of chronic refractory patellar tendinopathy |
|
van Ark
et al. (2013)
[31] | 1x USG, a low concentration of platelets
(433 × 109/L) injected | Prospective case series | 5/5; 2 M/3 F
(1 bilateral) | 27 (23–31) yr; ≥3 mo | Various treatments without any success | Rest, low load (0–2 wk); higher cycling intensity, home exercise program (2–4 wk); eccentric exercises, various exercises (5, 6 wk); exercises progressing to higher % 1RM, 3 × 8–15 reps., rest interval 30 sec., more muscular hypertrophy (7, 8 wk); daily eccentric training continues, advance to more sport-specific exercises (after 8 wk) | 6 wk; 12 wk; 16 wk; 26 wk | VISA-P | Five of the six tendons showed an improvement of at least 30 points on the VISA-P after 26 weeks | The combination treatment reported in this study is feasible and seems to be promising for patients in the late/degenerative phase of patellar tendinopathy |
|
Charousset
et al.
(2014) [32] | 3x USG PRP (2 mL) injections every 1 wk | Prospective case series | 28/28 | 27 (16–37) yr; ≥4 mo | Various treatments without any success | The rehabilitation program starting with warm-up exercises, stretching, and formal eccentric exercises on a flat board followed by progressive training such as cycling and mild exercises in the pool [71] | 4 wk; 3 mo; 6 mo; 12 mo; 18 mo; 24 mo | VISA-P; VAS; Lysholm; MRI | All patients showed an improvement in all scores at the 2 yr FU and twenty-one of 28 patients returned to their presymptom sporting level at 3 mo | PRP injection allows fast recovery of athletes with patellar tendinopathy to a presymptom sporting level |
|
Brown and
Sivan (2010)
[33] | 1x USG PRP (3 mL) injections were administered | Case study | 1/1; 1 M | 36 yr; ≥9 mo | Various treatments without any success | Minimize physical activity (the few days); slow quadriceps eccentric strengthening exercises (after 2 wk) | 6 wk | VISA-P; US; pain level | An improvement of at least 19 points on the VISA-P; a 50% reduction in pain; reduced thickness of the tendon | PRP injection is a safe and cost-effective treatment method for chronic patellar tendinopathy |
|
Rowan
and Drouin
(2013) [34] | 1x USG PRP (2 mL) injections were administered | Case study | 1/1; 1 F | 23 yr; ≥6 yr | Various treatments without any success | Non-weight bearing (0–2 wk); 50% weight-bearing (2-3 wk); eccentric decline-board squats and no other activity (3–7 wk); rehabilitation and aqua jogging (7–10 wk) | 2 mo | US; pain level | A diagnostic ultrasound confirmed complete resolution of the defect and the patients was symptom-free. | Emerging literature on PRP appears to be promising for patellar tendinopathy. |
|
Scollon-Grieve
and Malanga (2011) [35] | 1x USG PRP (5 mL) injections were administered | Case study | 1/1; 1 M | 18 yr; ≥1 yr | Various treatments without any success | Rest (1 wk); running, jumping, or doing resistance training (1–4 wk); progressive open chain resistance training (4–6 wk); closed chain exercises (after 6 wk) | 1 mo;
2 mo | US; pain level | An estimated 90% clinical improvement in function and a complete resolution of pain (1 mo FU); full activity without pain or limitation (2 mo FU) | PRP injection is a safe and promising alternative for patients with chronic patellar tendinopathy |
|
Mautner
et al.
(2013) [17] | Survey on satisfaction and functional outcome; PRP injections with USG were administered for tendinopathy refractory to conventional treatments | Retrospective; cross-sectional survey | 180/27; 100 M/80 F | 48 (19–73) yr; ≥6 mo | Various treatments without any success | A rehabilitation program (did not standardize the specific protocol) | 15 ± 6 mo | Likert scale; VAS; functional pain; overall satisfaction | Moderate improvement in symptoms: ≥50%
(patellar tendinopathy patients). Improvement in VAS: 78% (patellar tendinopathy patients) | Majority of patients reported a moderate improvement in pain symptoms |
|
| Dallaudière et al. (2014) [37] | Survey on satisfaction and functional outcome; a single intratendinous injection of PRP under US guidance | Retrospective
survey | 408/41 | ≥6 mo | Various treatments without any success | Not described | 6 wk; 32 mo | WOMAC; VAS; US | Significant improvement in WOMAC score and residual US size of lesions | Intratendinous injection of PRP allows rapid tendon healing and decreases in clinical complaints in patients |
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