Gu HZ, et al. - The clinical data of 26 young and middle-aged individuals with ankylosing spondylitis (AS) (31 coxae), who were treated with THA and followed-up for more than 3 years in the period between February 1998 and May 2013, were retrospectively assessed by the researchers in order to examine the curative impacts of THA in treating hip bony fusion. During the surgery, femoral proximal cleavage fracture occurred in one coxa and was fixed by the steel wire cerclage. Sciatic nerve traction injury occurred in one coxa following the surgery, which recovered post six months. Posterior hip dislocation occurred in one coxa and was instantly treated with manual reduction. All individuals were followed-up, and follow-up term varied within 36–123 months, with an average of 46.5 months. All the indexes significantly rose in comparison with pretreatment. A periacetabular radiolucent line occurred in one coxa with a width of < 2 mm, and no femoral radiolucent line was noted during follow-ups in any individual. Heterotopic ossification happened in four coxae. Thus, THA treatment for hip bony fusion caused by AS could attain satisfactory hip function recovery and outstanding prosthesis survival rate.