ABSTRACT
The purpose of this study was to verify the effect of protocatechuic acid (PCA) on tendon healing and fatty degeneration in a chronic rotator cuff model. Methods: Twenty-eight Sprague-Dawley male rats were randomly allocated into two groups: Saline+repair (SR) and PCA+repair (PR). The right shoulder was used for experimental interventions, and the left served as a control. PCA (30 mg/kg/day) was administered intraperitoneally at the site of infraspinatus tendon detachment in rats in the PR group, and the same volume of saline was administered to the same site in the SR group. The torn tendon was repaired 4 weeks after infraspinatus detachment. Four weeks after repair, hematoxylin and eosin (H&E), S100, and CD68 stains were performed to evaluate the degree of fatty degeneration and H&E and Masson trichrome stains were performed to assess tendon healing. Superoxide dismutase (SOD) was measured to test the efficacy of PCA as an antioxidant. Results: Results from histological evaluation indicated that SOD and CD68 levels at the musculotendinous region and collagen fiber parallel to the orientation at the tendon-to-bone junction were not significantly different between the SR and PR groups. The mean load-to-failure of the PR group (20.32±9.37 N) was higher than that of the SR group (16.44±6.90 N), although this difference was not statistically significant (p=0.395). The SOD activity in the operative side infraspinatus muscle of the PR group was higher than that of the SR group, but the difference was not statistically significant (p=0.053). Conclusions: The use of PCA could improve tendon healing and decrease fatty degeneration after rotator cuff repair.
ABSTRACT
Extensor muscle strengthening exercises with counterforce braces (EX) is a conventional conservative treatment for lateral epicondylitis (LE) of the elbow. In addition, polydeoxyribonucleotide (PDRN) or extracorporeal shockwave therapy (ESWT) has been recently used for LE. Methods: Sixty-three patients with chronic LE participated in this study and randomly allocated in three groups (G1: EX, G2: EX+PDRN injection, and G3: EX+ESWT). All of the three groups were taught to perform EX at the first out-patient department (OPD) visit. Group 2 was injected with 3 mL PDRN (5.625 mg/3 mL), while group 3 received ESWT at the first OPD visit. Visual analog scale pain score, Mayo elbow performance score (MEPS), and ultrasonographic examination were checked before, 6 weeks, and 12 weeks after the treatments. Results: Overall functional scores and ultrasonographic findings in all three groups improved after treatment. The mean MEPS in group 2 improved more than groups 1 and 3 at 6 weeks (G1, 56.9>62.4; G2, 54.3>65.0; G3, 55.7>62.6), and more than group 1 at 12 weeks (G1, 56.9>67.9; G2, 54.3>73.6). The mean common extensor tendon depth (CETD) on ultrasonography in group 2 increased more than groups 1 and 3 at 6 and 12 weeks (6 weeks: G1, 0.385>0.386; G2, 0.332>0.392; G3, 0.334>0.357; 12 weeks: G1, 0.385>0.409; G2, 0.332>0.438; G3, 0.334>0.405 [cm]). Conclusions: PDRN injections combined with EX exhibited a greater improvement in mean MEPS and mean CETD compared to EX only or EX combined with ESWT for LE within the 12 weeks follow-up.