Ankylosing spondylitis (AS) is a chronic immune inflammatory disease that affects 0.06%–0.25% of the population, and its prevalence varies across regions (Appel et al., 2006). AS primarily involves the sacroiliac joint and spine, is characterised by back pain, causes severe structural damage, and impairs the performance of daily activities (Chen et al., 2015). Spinal deformities and joint stiffness have been observed in patients with severe AS. Moreover, fusion of the spine or peripheral joints may occur in late-stage AS, which can impair motor function and activities of daily living and is associated with a heavy family economic burden (Zhang et al., 2003; Smith, 2015). The most important pathological features of AS include inflammation and new bone formation, which have been observed in patients with AS at the early and late stages, respectively (Sieper and Poddubnyy, 2017).

Currently, the therapeutic drugs available to treat AS primarily include nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and biological agents. These treatments exert potent anti-inflammatory effects but do not provide clear benefits regarding the progression of new bone formation in AS (Raychaudhuri and Deodhar, 2014; Garcia-Montoya et al., 2018). Specifically, non-steroidal anti-inflammatory drugs and disease-modifying anti-rheumatic drugs are widely used for AS, and provide clear anti-inflammatory, analgesic, and anti-rheumatic effects. However, these drugs require long-term use and are associated with adverse effects, including cardiovascular, gastrointestinal, and renal toxicities (Harirforoosh et al., 2013). In addition, biological agents are not suitable for all AS patients, and the use of biological agents in clinical practice is restricted by economic constraints and adverse events (Lopetuso et al., 2018). Therefore, additional effective treatments are required to improve the prognosis of patients with AS.

Traditional Chinese medicine fumigation (TCMF) and Yang-He decoction (YHD) have been used to treat AS in China. TCMF uses steam and stimulates the affected area, opening the pores of the skin, and enabling the active ingredients to be absorbed into the skin through the pores, and circulate throughout the entire body to relieve pain and treat the disease (Shu, 2016). The ingredients of YHD have been demonstrated to effectively improve the syndrome of yang deficiency, cold dampness, and deficiencies of the liver and kidneys. However, whether the combined use of TCMF and YHD provides superior effects in AS remains unclear. Therefore, we performed a systematic review and network meta-analysis to evaluate the therapeutic effects of TCMF and YHD in patients with AS.