BackgroundKnee ankylosis can result in major functional impairment, and surgical treatment of knee ankylosis is often regarded as a tremendous challenge due to technical difficulties such as difficult joint exposure and a high incidence of complications. The objective of this study was to review the results of preoperative and postoperative functional scores, range of motion (ROM), and complications of total knee arthroplasty (TKA) for the treatment of knee ankylosis. MethodsBetween January 2007 and January 2021, 19 patients (17 patients, 11 women, and 6 men) who had knee ankylosis underwent TKA. The mean age of the patients was 52 years (range, 31 to 71), and the mean follow-up period was 10.2 years (range, 3.1 to 13.9). The surgical procedure involved a TKA, performed via a medial parapatellar approach, a quadriceps snip, and a secondary osteotomy with soft tissue release. The postoperative clinical outcomes and complications were evaluated using a range of methods, including ROM assessment, Hospital for Special Surgery Knee Score, and visual analog scale scores. ResultsAt the final follow-up, the mean Hospital for Special Surgery Knee score improved significantly from the preoperative score of (33.6 ± 8.7) to (88.1 ± 5.2) (P < 0.001), ROM improved from (0 ± 0°) to (100.9 ± 14.1°) (P < 0.001), the visual analog scale score improved from a preoperative score of 0 to (1.0 ± 0.94) (P < 0.001), and radiographs showed no aseptic loosening of the knee. There were 8 knees (42.1%) that had postoperative complications. ConclusionsTotal knee arthroplasty (TKA) in patients who have ankylosing knees resulted in significant improvements in flexion and extension, mobility, and quality of life, despite a high incidence of complications such as skin necrosis.