AR（拡張現実）支援下人工膝関節全置換術におけるアライメント改善と周術期出血量減少：単一施設比較研究

Accurate component alignment is critical for successful total knee arthroplasty (TKA). Robotic-assisted TKA improves alignment compared with conventional jigged instrumentation, but requires additional imaging, incisions, consumables, and cost. Augmented reality-assisted TKA (AR-TKA) may offer comparable benefits without these disadvantages. We retrospectively reviewed 116 primary TKAs at a single centre, including 77 conventional jig-based procedures and 39 AR-assisted TKAs performed using the Knee+^® system (Pixee Medical, France). Primary outcomes were component alignment accuracy and reproducibility on standardized radiographs. Secondary outcomes included perioperative blood loss (haemoglobin drop), range of motion, operative time and patient-reported outcome measures (PROMS). AR-TKA improved femoral coronal alignment (90.3° ± 1.7 vs. 91.1° ± 2.1; p = 0.045) and reproducibility (p = 0.002). Femoral component flexion was more accurately achieved (p = 0.005). Tibial coronal alignment and slope did not differ significantly between the two groups. Blood loss was reduced with AR-TKA (Hb drop 13.4 vs. 18.6 g/L; p = 0.001). Postoperative ROM was greater in the AR-TKA group (130.8° vs. 123.5°; p = 0.011). There was no difference in the operative duration (67.9 vs. 72.4 min, p = 0.126). PROMs were favourable in both groups with no significant differences: FJS (72 vs. 66; p = 0.244), HAAS (10.4 vs. 10.6; p = 0.829), OKS (43.6 vs. 43.8; p = 0.803). AR-TKA achieved alignment accuracy and reproducibility comparable to conventional jig-based techniques, with reduced perioperative blood loss and improved postoperative range of motion. PROMS were favourable and comparable to published robotic-assisted series. These findings support AR-TKA as a pragmatic alternative to robotic systems, combining precision with efficiency in routine clinical practice.