Non-thermal atmospheric pressure gas discharge plasma enhances tendon-to-bone junction repair in a rabbit model

Katsumasa Nakazawa; Hiromitsu Toyoda; Tomoya Manaka; Kumi Orita; Yoshihiro Hirakawa; Yoichi Ito; Kosuke Saito; Ryosuke Iio; Yoshitaka Ban; Hana Yao; Yuto Kobayashi; Jun-Seok Oh; Tatsuru Shirafuji; Hiroaki Nakamura

doi:10.1016/j.jse.2024.07.039

Non-thermal atmospheric pressure gas discharge plasma enhances tendon-to-bone junction repair in a rabbit model

J Shoulder Elbow Surg. 2024 Sep 17:S1058-2746(24)00640-2. doi: 10.1016/j.jse.2024.07.039. Online ahead of print.

Authors

Affiliations

¹ Department of Orthopedic Surgery, Graduate School of Medicine, Osaka City University, Osaka, Japan.
² Department of Orthopedic Surgery, Graduate School of Medicine, Osaka City University, Osaka, Japan; Department of Orthopedic Surgery, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan. Electronic address: h-toyoda@omu.ac.jp.
³ Department of Orthopedic Surgery, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
⁴ Department of Orthopedic Surgery, Ishikiri Seiki Hospital, Osaka, Japan.
⁵ Ito Clinic, Osaka Shoulder Center, Osaka, Japan.
⁶ Department of Physics and Electronics, Graduate School of Engineering, Osaka Metropolitan University, Osaka, Japan.
⁷ Department of Orthopedic Surgery, Graduate School of Medicine, Osaka City University, Osaka, Japan; Department of Orthopedic Surgery, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.

PMID: 39299643
DOI: 10.1016/j.jse.2024.07.039

Abstract

Background: Plasma is a collection of active particles generated by dissociating molecules and ionizing atoms through applying high energy to a gas, such as high-sound heating or electrical shock. Recently, many reports have been published on the effectiveness of non-thermal atmospheric pressure gas discharge plasma (NTAPP) on living organisms. Furthermore, we have reported on the promotion of bone and tendon repair by NTAPP irradiation. We hypothesized that irradiation of NTAPP would promote the repair of the tendon-bone junction in a rotator cuff repair. This study investigated the effect of NTAPP irradiation on the healing process of the tendon-bone junction.

Methods: Among 36 Japanese white rabbits, the infraspinatus tendon was detached from the humeral insertion site. A 3.2 mm bone tunnel was then created at the original insertion site of the infraspinatus muscle. The left shoulder was irradiated with NTAPP at a distance of 1 cm from the bone tunnel for 5 minutes (plasma-treated group), while the right shoulder was not irradiated (control group). The rabbits were sacrificed at 2, 4, and 8 weeks postoperatively, and 6 of each were used for histological evaluation. Mechanical tests were also performed on 6 specimens each at 4 and 8 weeks.

Results: Histological evaluation showed that at 4 weeks, the histological tendon to bone maturing score was 6.8 ± 1.3 in the plasma-treated group and 4.8 ± 1.6 in the control group (P < .01); at 8 weeks it was 9.0 ± 1.0 in the plasma-treated group and 5.2 ± 1.1 in the control group (P < .01). Fibrocartilage formation and new bone formation were observed at both 4 and 8 weeks. In the mechanical test, the plasma-treated group had 75.0 ± 18.9 N in ultimate load to failure at 8 weeks. In the control group, it was 51.1 ± 7.9 N. (P = .04).

Conclusion: The repair of the rotator cuff at the tendon-bone junction was significantly improved at 4 and 8 weeks by irradiation with NTAPP.

Keywords: Non-thermal atmospheric pressure gas discharge plasma; infraspinatus tendon; irradiation; rotator cuff tear; shoulder injury; tendon-bone junction.