Oral nonsteroidal anti-inflammatory analgesic drugs, intra-articular corticosteroid injection, physical therapy and joint capsule release are used to treat shoulder stiffness and pain after repair surgery for rotator cuff injuries[23, 24]. It was found that compared with hyaluronic acid, fibroblast proliferation was lower and the rate of healing failure was higher when the corticosteroids were injected at the surgical site in the studies in animal repair models of rotator cuff injury[25, 26]. In addition, human tissue cytology studies have shown that corticosteroid treatment is associated with higher cell apoptosis at the surgical site. Although some basic studies have shown that corticosteroids may have a negative effect on postoperative tissue healing, some clinical studies have shown that early intraarticular injection of corticosteroids after arthroscopic rotator cuff repair does not increase the tear rate[21, 28]. Our research demonstrated that there was no significant difference in tear rate, constant score, ASES score and UCLA score. However, corticosteroids injection within 1 month after arthroscopic shoulder surgery will significantly increase the early infection rate.
The results of this meta-analysis showed that the corticosteroids injection group had no significant difference in tear rate compared with the control group, which is inconsistent with the research of BAVEREL. We consider that different characteristics of the included patients may be one of the potential reasons. only severely injured patients with rotator cuff full-thickness tearing were included in BAVEREL’s research. In this study, patients with partial or full-thickness rotator cuff tears and a mixture of the two were included. The differences of the study subjects may lead to inconsistent conclusions. Secondly, betamethasone is the intervention of the former study, while triamcinolone acetonide is the main intervention of this study. To some extent, the difference of corticosteroid types will affect the conclusion.
In this research, 2 included articles mentioned that no postoperative adverse reactions were found after corticosteroids administration. The most likely reason was that the sample size was relatively small. KEW compared the incidence of infection of 3946 patients undergoing shoulder arthroscopy operation between two groups. Finally, they found that the infection rate of patients who received corticosteroid injection within 1 month after operation was significantly higher, but there was no significant change in the infection rate of patients who received corticosteroid injection within 2–4 months after operation and this result is in line with previous studies[29, 30]. Postoperative infections are caused when pathogens enter the body during surgery or corticosteroid injection. The first month after the operation is considered as the inflammatory response period. Due to the immunosuppressive effect of corticosteroid, the ability of bacteria resistance declines causing infection.
Previous studies have reported that long-term use of corticosteroid will increase the incidence of complications within 30 days after arthroscopic shoulder surgery[29–31]. MARTIN reported the incidence of corticosteroid relevant complications such as reoperation (0.31%), superficial infection of the surgical site (0.16%), deep infection (0.01%), deep vein thrombosis or thrombophlebitis (0.09%), peripheral nerve injury (0.01%), pulmonary embolism (0.06%) in a study involving 9410 patients. HEYER  found that in addition to the long-term use of corticosteroid, patients older than 65 years old, male patients, ASA rating greater than level 2, history of chronic obstructive pulmonary disease, hypertension and operation time more than 90 minutes were all related to the increased incidence of adverse reactions.
The shortcomings of the research: First, only one of the included literatures is an RCT, which may be one of the sources of heterogeneity. Second, all the literatures are short-term observation studies with a follow-up time of no more than 3 years. This conclusion should not be applied to long-term observation results.