The Effect of Platelet-Rich Plasma on Achilles Tendon Healing in a Rabbit Model

Background: The paratenon is important for Achilles tendon healing. There is much interest in the use of exogenous growth factors (GFs) as potential agents for accelerating the healing of damaged Achilles tendons. Purpose/Hypothesis: The present study used a rat model to study the responses of the injured Achilles tendon to GFs in the presence or absence of the paratenon. The hypothesis was that responses of the injured tendon to GFs would be lower in the absence of a paratenon. Study Design: Controlled laboratory study. Methods: A 4-mm defect was created in the right Achilles tendon of 60 skeletally mature rats, which were treated with a validated combination of GFs (bFGF, BMP-12, and TGF-β1). Animals were randomly assigned to the intact paratenon (IP) group or resected paratenon (RP) group. Healing was studied anatomically, mechanically, and histologically after 1, 2, and 4 weeks. Results: IP tendons showed improved healing compared with RP tendons. IP tendons were significantly stronger (32.2 N and 48.9 N, respectively) than RP tendons (20.1 N and 31.1 N, respectively) after 1 and 2 weeks. IP tendons did not elongate as much as RP tendons and had greater cross-sectional areas (18.0 mm2, 14.4 mm2, and 16.4 mm2, respectively) after 1, 2, and 4 weeks compared with RP tendons (10.5 mm2, 8.4 mm2, and 11.9 mm2, respectively). On histology, earlier collagen deposition and parallel orientation of fibrils were found for IP tendons. Conclusion: The paratenon is essential for efficient Achilles tendon healing. Healing with GFs in this Achilles tendon defect model was superior in the presence of the paratenon. Clinical Relevance: Biological approaches to tendon engineering using GFs are in vogue and have been shown to improve healing of the rat Achilles tendon, most likely by inducing progenitor cells located within the paratenon. Clinically, resection or incision of the paratenon has been proposed for wound closure. Our data demonstrate the fundamental importance of the paratenon, which therefore should be preserved during Achilles tendon repair, especially if augmented with products such as platelet-rich plasma or autologous conditioned serum that are rich in GFs.

Download Full-text

Improved Healing of Transected Rabbit Achilles Tendon after a Single Injection of Cartilage-Derived Morphogenetic Protein-2

The American Journal of Sports Medicine ◽

10.1177/03635465030310041301 ◽

2003 ◽

Vol 31 (4) ◽

pp. 555-559 ◽

Cited By ~ 61

Author(s):

Carina Forslund ◽

Per Aspenberg

Keyword(s):

Achilles Tendon ◽

Single Injection ◽

Rabbit Model ◽

Tendon Healing ◽

Radiographic Examination ◽

Morphogenetic Protein ◽

Tendon Ruptures ◽

The Right ◽

Callus Size ◽

Positive Effect

Background Achilles tendon ruptures in humans might be treated more efficiently with the help of a growth factor. Cartilage-derived morphogenetic protein-2 has been shown to induce formation of tendon-like tissue. Hypothesis Cartilage-derived morphogenetic protein-2 has a positive effect on mechanical parameters for tendon healing in a rabbit model with Achilles tendon transection. Study Design Controlled laboratory study. Methods The right Achilles tendon of 40 rabbits was transected without tendon suture. Cartilage-derived morphogenetic protein-2 (10 μg) or vehicle control (acetate buffer) was injected locally 2 hours postoperatively. All tendons were tested biomechanically at 8 and 14 days, and treated tendons were histologically and radiographically evaluated at 56 days. Results At 14 days, both failure load and stiffness of treated tendons were increased by 35%. The treated tendons had significantly larger callus size at 8 and 14 days. Histologic and radiographic examination showed no signs of ossification in the treated tendons after 56 days. Conclusions A single injection of cartilage-derived morphogenetic protein-2 led to a stronger and stiffer tendon callus than that in the controls without inducing bone formation. Clinical Relevance Similar results from a larger animal model would suggest a possible future use of cartilage-derived morphogenetic protein-2 in the treatment of human Achilles tendon ruptures.

Download Full-text

Quantitative Assessment of Tendon Healing by Using MR T2 Mapping in a Rabbit Achilles Tendon Transection Model Treated with Platelet-rich Plasma

Radiology ◽

10.1148/radiol.2015141544 ◽

2015 ◽

Vol 276 (3) ◽

pp. 748-755 ◽

Cited By ~ 17

Author(s):

Taisuke Fukawa ◽

Satoshi Yamaguchi ◽

Atsuya Watanabe ◽

Takahisa Sasho ◽

Ryuichiro Akagi ◽

...

Keyword(s):

Achilles Tendon ◽

Quantitative Assessment ◽

Platelet Rich Plasma ◽

T2 Mapping ◽

Tendon Healing

Download Full-text

Science to Practice: Quantitative US Elastography Can Be Used to Quantify Mechanical and Histologic Tendon Healing in a Rabbit Model of Achilles Tendon Transection

Radiology ◽

10.1148/radiol.2017170126 ◽

2017 ◽

Vol 283 (2) ◽

pp. 311-313 ◽

Cited By ~ 1

Author(s):

Kenneth S. Lee ◽

Jack Martin ◽

Darryl Thelen

Keyword(s):

Achilles Tendon ◽

Rabbit Model ◽

Tendon Healing ◽

Quantitative Us ◽

Us Elastography

Download Full-text

Real-time sonoelastography evaluation of the Achilles tendon following ultrasound-guided platelet-rich plasma injection and eccentric exercise for the treatment of refractory Achilles tendinopathy

Ultrasound ◽

10.1177/1742271x18818608 ◽

2018 ◽

Vol 27 (3) ◽

pp. 138-147

Author(s):

Chin Chin Ooi ◽

Michal Schneider ◽

Peter Malliaras ◽

Meng Ai Png ◽

Martine Chadwick ◽

...

Keyword(s):

Achilles Tendon ◽

Eccentric Exercise ◽

Platelet Rich Plasma ◽

Tendon Healing ◽

Inverse Correlation ◽

Strain Ratio ◽

Achilles Tendinopathy ◽

Post Treatment ◽

Tendon Stiffness ◽

Plasma Injection

The objective of this study was to investigate the feasibility of using sonoelastography to depict Achilles tendon stiffness after platelet-rich plasma injection and eccentric exercise for chronic Achilles tendinopathy, and to correlate sonoelastography findings with clinical outcome up to 12 months after treatment. Forty-five Achilles tendons from 45 patients (33 males, 12 females; mean age 51 years) were examined using sonoelastography and ultrasound at baseline, 4–6 weeks, 6 months and 12 months post-treatment. The strain ratio (between Achilles tendon and Kager's fat) during sonoelastography was obtained. The proportion of tendons with hypoechogenicity and neovascularity were documented. Clinical outcomes were assessed by the Victorian Institute of Sport Assessment-Achilles questionnaire and correlated with sonographic findings. The Victorian Institute of Sport Assessment-Achilles improved significantly from 38.4 (±14.1) at baseline, 77.2 (±12.5) at 6 months ( p < 0.001) to 81.2 (±10.8) at 12 months ( p < 0.001). The strain ratio values were 2.16 (±1.02) at baseline, 2.03 (±0.67) at 4–6 weeks, 1.81 (±0.62) at 6 months and 1.19 (±0.34) at 12 months with a significant reduction observed at 6 months (p = 0.006) and 12 months ( p < 0.001). At 12-month evaluation, none of the tendons regained a normal echotexture. Strain ratio demonstrated a moderately good inverse correlation with Victorian Institute of Sport Assessment-Achilles (r = −0.610, p<0.001) while B-mode and Doppler ultrasound did not show a significant correlation (r = −0.041, p = 0.817, and r = −0.116, p = 0.514). Achilles tendon stiffness shows moderately good correlation with clinical symptom at 12-month post-treatment. Sonoelastography using strain ratio could be a promising ancillary tool for monitoring Achilles tendon healing after treatment.

Download Full-text