Blood Supply.

It has been suggested that blood circulation within the tendons contributes to repair of the tendon after the exercises. Recently, blood circulation of human tendons could be measured using red laser lights (Kubo et al. 2008b). Using this technique, we were able to measure changes in blood volume and oxygen saturation of human tendons by various treatments. During a 60-min heating, the blood volume and oxygen saturation of the tendon increased significantly from the resting level, and continued to increase by 35 min. These changes in blood circulation of tendon were considerably different from the temperatures of muscle and skin. Furthermore, when the needle tip was moved up and down from the targeted depth (up-and-down manipulation) at approximately 1 mm amplitude, the blood volume and oxygen saturation of the treated tendon increased significantly. After the removal of the acupuncture needle, the blood volume and oxygen saturation of the tendon increased gradually for the non-treated side. These results suggested that the change in blood circulation of the tendon during acupuncture with up-and-down manipulation was caused by axon reflex, and increase in blood flow in the tendons after the needle removal might be caused through the central nervous system. It is well known that heating and acupuncture treatments were quite effective in the management of tendon injuries. Therefore, these phenomena would be related to the changes in blood circulation of tendons due to heating and acupuncture treatments.

The blood-tendon barrier: identification and characterisation of a novel tissue barrier in tendon blood vessels.

In the last decade, nanobiotechnology research has emerged as a revolutionising new approach to the 21st century pharmaceutical challenges, offering valuable gains in a vast set of biomedical applications. In the field of bone tissue engineering, a broad range of nanotechnology-based delivery systems have been researched and the most recent developments in high-throughput technology and in silico approaches are creating very high expectations. This review presents a comprehensive overview of the emergent nanotechnology-based materials, processing techniques and research strategies for the delivery of pharmaceutics to bone including the materials general characteristics and the available drug delivery systems to distribute agents systemically or locally. Complementary to what was stated above, it also reviews the latest high-throughput processing techniques and the existent in silico tools (mathematical and computational models) used to help on the design of delivery systems.

Effect of phototherapy with light-emitting diodes (890 nm) on tendon repair: an experimental model in sheep.

The effect of phototherapy with 890-nm light-emitting diodes (LEDs) on the healing of experimentally induced tendinitis in sheep was evaluated in this study. Partial tenotomies measuring 0.2 cm wide × 0.5 cm long were performed on the second third of the superficial digital flexor tendons of 10 healthy sheep. The animals were divided into two groups: "treated" (TG), treated with LEDs at the aforementioned wavelength, and "control" (CG), a control group treated with a placebo. Kinesiotherapy, which consisted of 5-min walks on grassy ground, was performed on both groups. B-mode and power Doppler ultrasonographies (US) were performed to evaluate the tendon healing process during the first 14 days after surgery and on the 21st and 28th postoperative days. Biopsies were performed on day 28 for the histopathological assessment of neovascularisation and the pattern of the tendon fibres. The absence of lameness and a significant improvement (p < 0.05) in the sensitivity to pain during palpation were observed in the treated group. Furthermore, a significant reduction in oedema and an increased number of vessels (p < 0.05) were observed in this group with the B-mode and power Doppler US, respectively. No significant difference in the evolution of the lesion was found. There was a histological difference (p < 0.05) in neovascularisation in the treated group. Phototherapy with 890-nm light-emitting diodes decreases the inflammatory process.

Microcurrent therapy in the management of chronic tennis elbow: pilot studies to optimize parameters.

BACKGROUND AND PURPOSE: In microcurrent therapy (MCT), low-intensity electric current is applied to promote tissue healing and relieve symptoms. MCT is used with recalcitrant skin and bone lesions, but little is known about its effects on tendinopathy, and optimal treatment parameters are uncertain. Two studies were conducted to ascertain whether varying (i) current intensity and (ii) waveform and treatment duration affect outcomes of MCT for chronic tennis elbow. METHODS: Two trials compared the effects of different MCT parameters on pain and function, grip strength, and sonographically graded tendon structure and hyperaemia. Trial 1 compared monophasic MCT of intensity 50 and 500 µA applied for 35 h; trial 2 compared devices delivering approximately 25 µA but with different waveforms and durations of 15 and 189 h, respectively. Treatment was applied over 3 weeks. Assessments were at baseline and 3, 6 and 15 weeks. RESULTS: For each trial, n = 31. In trial 1, 50 µA was more effective than 500 µA, with 93% of participants 'much better' or 'fully recovered' at 15 weeks, compared with 47% in the 500 µA group. Tendon structural normalization was superior at 50 µA, but no significant differences were found in other outcomes. In trial 2, success rates for the two groups at 15 weeks were 75% and 73%, respectively, but group improvements did not differ significantly on any measure. Pooled analysis of data from both trials showed that, immediately following treatment, blood flow had fallen in the subgroup with high baseline scores and risen in the subgroup with low scores. Low baseline score correlated significantly with treatment success. CONCLUSION: Monophasic MCT of peak current intensity 50 µA applied for tens of hours may be effective in reducing symptoms and promoting tendon normalization in chronic tennis elbow. Hyperaemia may help predict treatment outcome. A full-scale trial of the therapy is warranted.

Injectable agents derived from or targeting vascularity: has clinical acceptance in managing tendon disorders superseded scientific evidence?

OBJECTIVES: To report outcomes after sclerosing, platelet-rich plasma (PRP) and autologous blood injection therapies as a treatment for tendinopathy. METHODS: We searched Pubmed for clinical trials on sclerosing, PRP and autologous blood injections for tendinopathy. We scored the quality of the studies using a modified Coleman Methodological Score (CMS) with 9 criteria, which results in a final score between 0 and 90. RESULTS: We included 14 studies involving 328 tendons on sclerosing (mean CMS: 52; range 31-77), 6 studies involving 143 tendons on PRP (CMS: 57; 43-73) and 5 studies involving 160 tendons on autologous blood injections (CMS: 58, 50-68). Across treatments, the results appear promising, but as reflected by the low methodology scores, the majority of studies are non-randomized, retrospective, with small sample size or of short duration. Two of three RTCs on sclerosing injections reported better outcomes in the treatment group, while two RCTs on PRP injections show conflicting results. The only available RTC on autologous blood injections has only 8 weeks follow-up. CONCLUSIONS: There is a need for large-scale RTCs with appropriate follow-up and study size to determine the efficacy of sclerosing, platelet-rich plasma and autologous blood injection therapies as a treatment for tendinopathy.

Effects of hyperbaric oxygen treatment on tendon graft and tendon-bone integration in bone tunnel: biochemical and histological analysis in rabbits.

Despite moderate success in clinical applications, outcome of tendon grafts employed for anterior cruciate ligament (ACL) reconstruction remains unsatisfactory. This study investigated the effects of hyperbaric oxygen (HBO) on neovascularization at the tendon-bone junction, collagen fibers of the tendon graft, and the tendon graft-bony interface incorporated into the osseous tunnel in rabbits. Forty rabbits were assigned to two groups. The HBO group was exposed to 100% oxygen at 2.5 atmospheres pressure for 2 h daily, 5 consecutive days in a week. The control group was maintained in cages exposed to normal air. Histological studies of 12 rabbits were performed postoperatively at 6, 12, and 18 weeks. Biomechanical studies of 24 rabbits were conducted postoperatively at 12 and 18 weeks. Electron microscopy (EM) analyses of four rabbits were performed postoperatively at 18 weeks. Experimental results demonstrated that a higher number of Sharpey's fibers bridged the newly formed fibrocartilage and graft in the HBO group than in the control group. In addition, HBO treatment increased neovascularization and enhanced the incorporation of the progressive interface between tendon graft and bone. Biomechanical analysis showed that the HBO group achieved higher maximal pullout strength than the control group. Examination by EM showed that HBO treatment resulted in regenerated collagen fibers with increased compaction and regularity. Based on experimental results, HBO treatment is a treatment modality that potentially improves outcome following ACL reconstruction.