A Comparative Study on the Effects of Repeated Subacromial Injections of Parecoxib and Triamcinolone in a Rat Model of Normal Rotator Cuff
- Author:
Jong Pil YOON
1
;
Dong Hyun KIM
;
Sung-Jin PARK
;
Yoon Seong CHOI
;
Hyun Joo LEE
;
Seok Won CHUNG
;
Kang-San LEE
;
Jeoung Wook LEE
Author Information
- Publication Type:Original Article
- From:Clinics in Orthopedic Surgery 2025;17(2):291-299
- CountryRepublic of Korea
- Language:English
-
Abstract:
Background:This study aimed to investigate changes after repeated subacromial drug injections in a rat model of normal rotator cuff.
Methods:Thirty-nine male Sprague-Dawley rats were divided into groups 1 (no injection, n = 3), 2 (parecoxib, n = 18; 6 subgroups, n = 3 each; 0.5 mg/kg), and 3 (triamcinolone, n = 18; 6 subgroups, n = 3 each; 0.3 mg/kg). Groups 2 and 3 received subacromial injections 1–6 times once weekly for 6 weeks. The supraspinatus and infraspinatus tendons and muscles were used for biomechanical and histological evaluation. The subacromial bursa was used to analyze the prostaglandin E2 (PEG2) level.
Results:In the biomechanical test, load-to-failure and ultimate stress decreased in groups 2 and 3 with repeated injections and the values were significantly lower in group 3 than in group 1 only at the sixth injection (p = 0.007 and p = 0.008, respectively). On the Bonar score, the cellularity, ground substance, and total score were significantly different among the 3 groups at the fifth and sixth injections (cellularity: p = 0.028 and p = 0.033, ground substance: p = 0.018 and p = 0.006, and total score: p = 0.029 and p = 0.027, respectively). The myocyte cross-sectional area of the infraspinatus muscle showed a significant difference among the 3 groups at the third and fourth injections (p = 0.031 and p = 0.020, respectively). The PEG2 level in the subacromial bursa was significantly different among the 3 groups at the third, fifth, and sixth injections (p = 0.019, p = 0.004, and p = 0.004, respectively).
Conclusions:In the rat model of normal rotator cuff, repeated local injections of the cyclooxygenase-2 inhibitor showed fewer negative effects on the biomechanical and histological properties of the normal tendon than triamcinolone.
