Operative accuracy and clinical outcomes of robotic total knee arthroplasty in high-altitude versus low-altitude regions: a TB-CQ randomized clinical trial

Background: Robot-assisted total knee arthroplasty (RA-TKA) has shown favorable global outcomes, but evidence in specific environments is lacking. This study compared the operative accuracy and clinical outcomes of RA-TKA between high- and low-altitude regions. Methods: A 2-year prospective, open-label, parallel-arm, assessor-blinded clinical trial recruited 200 patients (study period: July–December 2022; final follow-up: December 2024). And, 100 high-altitude (Xigaze, Tibet, 3900 m) patients were randomized to conventional manual TKA (hCM-TKA) or robotic-assisted TKA (hRA-TKA); 100 low-altitude (Xinqiao, Chongqing, 300 m) patients to lCM-TKA or lRA-TKA. A dual approach was used: a standard Randomized Controlled Trial for intra-altitude comparison (hRA-TKA vs hCM-TKA), and an observational study for cross-altitude comparison (hRA-TKA vs lRA-TKA). Primary outcome was operative accuracy, assessed via subsectional operation time, bone-cutting errors, component positioning, and lower-extremity alignment. Secondary outcomes included blood loss, serum inflammation, patient-reported outcome measures (PROMs), adverse events (AEs), complications, readmission/operation rates, and patient/prosthesis survivals. Results: In total, 150 patients (mean age, 66.14 ± 7.00 years; 78.7% female) completed 24-month follow-up. Compared to hCM-TKA, hRA-TKA shortened bone-cutting (7.50 min, P < 0.05) and gap-balancing (4.00 min, P < 0.01) time, decreased bone-cutting errors (Grade II/III) by 38.9% ( P < 0.05), improved PROMs [Knee Society Score + 27.1, Component Summary of Short Form 12 Health Survey (SF-12) + 8.7, P < 0.01], and reduced AEs and complications (28.0%)/readmission (20.0%, P < 0.05). Compared to lRA-TKA, hRA-TKA demonstrated increased operative time [estimates (Est.) 15.37 min, 95% confidence interval (CI): 7.10, 23.65; P < 0.05] and blood loss (Est. 316.77 ml, 95% CI: 110.08, 523.45; P < 0.05), higher Western Ontario and McMaster Universities Osteoarthritis Index (Est. 23.93 points, 95% CI: 9.45, 38.41; P < 0.05) but higher patient satisfaction (Est. −2.06, 95% CI: −3.51, −0.62; P < 0.05) and Mental Component Summary of SF-12 (Est. 11.57 points, 95% CI: 6.39, 16.76; P < 0.05); no AEs/readmission/survival differences. Conclusions: Robot technology in TKA at high-altitudes can achieve comparable operative accuracy and clinical outcomes as at low-altitudes. However, extended surgical duration and increased blood loss warrant clinical precaution, even though they do not compromise the overall outcome. http://links.lww.com/JS9/H256