Objective:To explore the early learning curve of OrthoPilot navigation assisted total knee arthroplasty (TKA).Methods:Data of 40 consecutive cases of OrthoPilot navigation assisted TKA completed by the same surgical team in our department were retrospectively analyzed. According to the operation order, 40 cases were divided into the original phase group (the first 20 cases) and the subsequent phase group (the second 20 cases). In original phase group, the average age was 69.85±6.86 years with mean body mass index 24.10±2.88 kg/m 2, preoperative HSS score 48.80±5.33, preoperative knee ROM 87.05°±11.02° and preoperative alignment deviation of 7.40°±5.59°. In subsequent phase group, the average age was 66.65±7.92 years with mean body mass index 22.85±3.15 kg/m 2, preoperative HSS score 49.00±5.47, preoperative knee ROM 85.80°±11.65° and preoperative alignment deviation of 8.22°±5.21°. Perioperative data such as operative duration, incision length, hemoglobin drop and postoperative hospital stay, radiographic outcomes including hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), sagittal femoral component angle (sFCA), sagittal tibial component angle (sTCA), joint line convergence angle (JLCA), and functional scores were compared between the two groups. Results:All 40 cases were followed up for 24-33 months (mean, 27.38± 2.73 months). No severe postoperative complications such as infection and loosening occurred during the follow-up. The mean operative duration was 112.35±25.49 min in original phase group versus 82.10±10.96 min in subsequent phase group ( P< 0.05). The durations of tibial cutting was 11.95±3.27 min in original phase group versus 7.35±2.23 min in subsequent phase group ( P< 0.05); the femoral planning + cutting time was 20.95±6.91 min in original phase group versus 16.60±4.78 min in subsequent phase group, and trial + prosthesis implantation time was 39.65±7.72 min in original phase group versus 25.10±5.72 min in subsequent phase group,which was significantly higher in original phase group. There was no significant difference in other perioperative data such as incision length, hemoglobin drop and postoperative hospital stay between the two groups. As for radiographic outcomes, there was no statistical difference between the two groups in the postoperative angular deviation of HKAA (0.70°±0.80° vs. 0.80°±1.06°), mLDFA (0.89°±0.91° vs. 1.00°±0.86°), mMPTA (0.77°±0.53° vs. 0.76°±1.03°), sFCA (0.73°±0.48° vs. 0.87°±1.06°), sTCA (0.95°±0.58° vs. 1.16°±1.14°) and JLCA (0.27°±0.25° vs. 0.39°±0.18°). In original phase group, the HSS scores preoperative and 3 days postoperative were 48.80±5.33 and 60.05±5.10 respectively, and those in subsequent phase were 49.00±5.47 and 60.75±4.47 respectively, and both groups showed satisfactory functional recovery. There was no significant difference in HSS scores at all follow-up time points between two phases, as well as ROM (113.20°±9.82° vs. 113.50°±12.44°) and FJS-12 scores (78.00°±10.98° vs. 76.65°±10.29°) at 2 years postoperatively. Conclusion:In this study, we described a time-related early learning curve for OrthoPilot navigation-assisted TKA, in which the operative duration tended to be shorter after the first 20 cases. However, benefiting from good operative accuracy and repeatability, satisfactory radiographic and functional outcomes can be obtained in early stage of the learning curve.

Objective:To evaluate the feasibility and clinical outcomes of navigation-assisted total knee arthroplasty (TKA) using adjusted restricted kinematic alignment (arKA).Methods:Data of 14 consecutive cases of OrthoPilot navigation-assisted TKA using arKA from October 2019 to September 2021 were retrospectively analyzed, including 3 males and 9 females. The average age was 67.71±8.96 years with mean body mass index (BMI) 25.94±3.12 kg/m 2. 27 consecutive patients who underwent navigation-assisted TKA using aMA during the same period were assessed as the control group. There were no significant differences in gender, age or BMI between the two groups. Intraoperative parameters including operative duration, tibia resection angle, frontal femoral angle, axial femoral angle, joint line translation, medial and lateral gap in extension and flexion position were recorded. Radiographic parameters including hip-knee-ankle (HKA) angle, coronal femoral component angle (cFCA), coronal tibial component angle (cTCA), sagittal femoral component angle (sFCA) and sagittal tibial component angle (sTCA) were measured. Functional outcomes were assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Hospital for Special Surgery (HSS) score. Surgery-related complications were recorded. Results:All cases were followed up. The mean follow-up of arKA group was 18.57±6.98 months and follow-up of aMA group was 22.15±4.91 months. The intraoperative tibial resection was 3.07°±1.00° in arKA group versus 0.67°±0.56° in aMA group ( P<0.05). The lateral cutting height of tibia was 9.07±1.82 mm in arKA group versus 6.89±2.94 mm in aMA group ( P<0.05). The lateral gap in flexion was 1.71±0.83 mm in arKA group versus 1.04±0.71 mm in aMA group ( P<0.05). The difference of medial-lateral flexion laxity was 1.14±0.86 mm in arKA group versus 0.41±0.75 mm in aMA group ( P<0.05). The postoperative HKA angle was 174.10°±1.63° in arKA group versus 177.12°±2.07° in aMA group ( P<0.05). The cTCA was 87.58°±0.85° in arKA group versus 89.14°±1.23° in aMA group ( P<0.05). The cFCA was 93.10°±1.75° in arKA group versus 90.41°±3.01° in aMA group ( P<0.05). There was no statistical difference between the two groups in sFCA (1.30°±0.82° vs. 1.56°±1.19°), sTCA (87.16°±0.95° vs. 87.79°±1.04°) and femoral notching (7.1% vs. 11.1%). The preoperative HSS score in arKA group was 46.07±4.68 and HSS score at 1 month postoperatively was 73.86±3.48 ( P<0.05). The preoperative HSS score in aMA group was 47.04±4.52 and HSS score at 1 month postoperatively was 74.04±3.57 ( P<0.05). There was no statistical difference between the two groups in WOMAC score (12.93±2.37 vs. 12.63±2.34) and HSS score (86.86±2.74 vs. 86.11±2.95) at 6 months postoperatively. 2 cases (14.3%) in arKA group and 5 cases (18.5%) in aMA group had deep venous thrombosis (χ 2=0.12, P=0.733). Conclusion:Navigation-assisted TKA using arKA offers the surgeons a new alignment option for severe knee deformity with satisfactory clinical outcomes, the arKA technique has advantages in soft tissue protection and gap balance regulation compared to aMA technique.

Objective:To explore the effect of enhanced recovery after surgery (ERAS) protocols in patients undergoing laparoscopic radical cystectomy (LRC) and intracorporeal urinary diversion (ICUD).Methods:A total of 83 patients who received LRC+ ICUD in Beijing Chaoyang Hospital from March 2014 to September 2020, were divided into 2 groups based on different perioperative management, including 29 ERAS cases and 54 conventional recovery after surgery (CRAS) cases. The ERAS group included 26 males and 3 females , with an average age of (62.07 ± 9.26) years. There were 26 patients with ASA class Ⅰ-Ⅱ, 3 patients with ASA class Ⅲ, 4 patients received neoadjuvant chemotherapy, and 7 patients had a history of abdominal surgery in ERAS group. The CRAS group included 44 males and 10 females , with an average age of (61.59 ± 10.16) years. There were 50 patients with ASA class Ⅰ-Ⅱ, 4 patients with ASA class Ⅲ, 9 patients received neoadjuvant chemotherapy, and 10 patients had a history of abdominal surgery in CRAS group. There were no statistically significant differences in the baseline characteristics between the two groups. The patients in both groups underwent LRC+ ICUD procedures. The perioperative results and complications between the two groups were compared.Results:In the ERAS group, there were 20 patients who underwent Bricker ileal conduit surgery and 9 patients who underwent Studer orthotopic ileal neobladder surgery. Pathological staging included 3, 3, 7, 7, 5 and 4 cases in stage T a, T is, T 1, T 2, T 3 and T 4a, respectively. There were 23, 2, 3 and 1 patient with pathological stage N 0, N 1, N 2 and N 3, respectively. Pathological diagnosis included 3 cases of low-grade urothelial carcinoma, 24 cases of high-grade urothelial carcinoma, and 2 cases of other histological subtypes. In the CRAS group, there were 31 patients who underwent Bricker ileal conduit surgery and 23 patients who underwent Studer orthotopic ileal neobladder surgery. Pathological staging included 5, 3, 12, 9, 15 and 10 patients in stage T a, T is, T 1, T 2, T 3 and T 4a, respectively. There were 35, 6, 7 and 6 patients with pathological stage N 0, N 1, N 2, and N 3, respectively. Pathological diagnoses included 6 cases of low-grade urothelial carcinoma, 45 cases of high-grade urothelial carcinoma, and 3 cases of other histological subtypes. There were no statistically significant differences ( P>0.05) in surgical methods, pathological staging, or pathological types between the ERAS and CRAS groups. ERAS group presented less albumin loss [(25.73±8.63)% vs. (32.63±9.05)%, P=0.001], shorter hospital stay [9(7, 13)d vs. 12(9, 16)d, P=0.006], less 30-day overall complications [55.2% (16/29) vs. 83.3% (45/54), P=0.009]. In multivariable analysis, maximum albumin loss≥20% was independently associated with 30-day minor complications ( P=0.049), and maximum albumin loss ≥25% was independently associated with hospital of stay≥10 days ( P=0.038), respectively. Conclusions:For patients who received LRC+ ICUD, ERAS was associated with reduced perioperative albumin loss, shorter length of stay, less 30-day complications, accelerated recovery time, improved clinical outcome and less albumin injection.