BACKGROUND:Mechanical alignment is the"gold standard"alignment technique in total knee arthroplasty,but regardless of advances in prosthetic materials and robotic-assisted navigation,mechanical alignment-total knee arthroplasty still has a patient dissatisfaction rate of about 20％.OBJECTIVE:To evaluate the early efficacy of navigation-assisted total knee arthroplasty using functional alignment.METHODS:A total of 44 consecutive cases(50 knees)that underwent computer navigation-assisted total knee arthroplasty with functional alignment from October 2019 to June 2023 were retrospectively analyzed,including 12 males(14 knees)and 32 females(36 knees).A total of 46 consecutive cases(50 knees)that underwent navigation-assisted total knee arthroplasty with mechanical axis alignment by the same surgical team during the same period were selected as controls,including 5 males(5 knees)and 41 females(45 knees).The tibial osteotomy angle,tibial plateau osteotomy amount,femoral osteotomy angle,distal femoral,posterior and anterior osteotomy amount,and joint line movement were observed in the two groups of patients.Preoperative and postoperative flexion and extension gap internal and external laxity,hip-knee-ankle angle,mechanical lateral distal femoral angle,mechanical medial proximal tibial angle,joint line convergence angle,sagittal femoral component angle,posterior tibial slope,arithmetic hip-knee-ankle angle,joint line obliquity,coronal plane alignment of the knee classification,Western Ontario and McMaster Universities Osteoarthritis Index,and Hospital for Special Surgery score and forgotten joint score were compared between the two groups.RESULTS AND CONCLUSION:(1)The intraoperative tibial plateau osteotomy angle in the functional alignment group was greater than that in the mechanical axis alignment group,and the proportion of gap imbalance(2％)was smaller than that in the mechanical axis alignment group(18％).The differences were all significant(P＜0.05).(2)The hip-knee-ankle angle,mechanical medial proximal tibial angle,arithmetic hip-knee-ankle angle,and joint line obliquity in the functional alignment group were smaller than those in the mechanical axis alignment group postoperatively,and the differences were significant(P＜0.05).(3)The most common coronal plane alignment of the knee classification before surgery was type Ⅰ(80％in the functional alignment group and 42％in the mechanical axis alignment group).(4)The proportion of joint line obliquity＜177°(44％)in the functional alignment group was greater than that in the mechanical axis alignment group(14％)postoperatively.(5)Hospital for Special Surgery score at 1 month,6 months,and last follow-up after surgery was higher in the functional alignment group than that in the mechanical axis alignment group;the differences were statistically significant(P＜0.05).The Western Ontario and McMaster Universities Osteoarthritis Index 1 month after surgery was lower in the functional alignment group than that in the mechanical axis alignment group;the difference was statistically significant(t=-2.85,P=0.005).There was no significant difference in postoperative range of motion and forgotten joint score between the two groups(P＞0.05).(6)It is indicated that navigation-assisted total knee arthroplasty using functional alignment optimizes early clinical efficacy.The functional alignment technique has advantages in restoration of constitutional alignment and joint line obliquity and avoids soft tissue release compared to mechanical alignment technique.

Objective:To investigate the efficacy and safety of bendamustine combined with anti-CD20 monoclonal antibody in the first-line treatment of older patients with indolent B-cell non-Hodgkin lymphoma (B-iNHL) .Methods:The clinical data of 159 patients with B-iNHL enrolled in 16 hospitals from Jiangsu Cooperative Lymphoma Group from December 1, 2019, to April 20, 2024, were analyzed for regimen efficacy and safety. Bendamustine plus rituximab (BR) and bendamustine plus obinutuzumab (BG) were administered to 139 (87.4% ) and 20 (12.6% ) patients, respectively.Results:Among the 159 patients, 101 (63.5% ) were male and 58 (36.5% ) were female, with a median age of 69 years (range: 60–84). Efficacy could be assessed in 138 (86.8% ) patients. The efficacy assessment demonstrated that the overall response rate was 92.0% with complete and partial remissions in 75 (54.3% ) and 52 (37.7% ) cases, respectively. With a median follow-up of 24 months (range: 4–64), the progression-free survival rate was (87.5 ± 3.0) % and the overall survival rate was (83.2 ± 3.3) %. Of the 27 patients who died, 6 (22.2% ) died due to disease progression. The mean applied dose of bendamustine per cycle was 73.0 (50.8–89.7) mg/m 2 per day, administered on days 1 and 2. Adverse events of grade 3 or higher were reported in 53 (33.3% ) patients, with infection (30 cases,18.9% ) and neutropenia (24 cases, 15.1% ) demonstrating the highest incidence. Conclusion:Bendamustine combined with anti-CD20 monoclonal antibody demonstrated good efficacy and is well-tolerated in the first-line treatment of elderly patients with B-iNHL.

Objective:To investigate the efficacy and safety of bendamustine combined with anti-CD20 monoclonal antibody in the first-line treatment of older patients with indolent B-cell non-Hodgkin lymphoma (B-iNHL) .Methods:The clinical data of 159 patients with B-iNHL enrolled in 16 hospitals from Jiangsu Cooperative Lymphoma Group from December 1, 2019, to April 20, 2024, were analyzed for regimen efficacy and safety. Bendamustine plus rituximab (BR) and bendamustine plus obinutuzumab (BG) were administered to 139 (87.4% ) and 20 (12.6% ) patients, respectively.Results:Among the 159 patients, 101 (63.5% ) were male and 58 (36.5% ) were female, with a median age of 69 years (range: 60–84). Efficacy could be assessed in 138 (86.8% ) patients. The efficacy assessment demonstrated that the overall response rate was 92.0% with complete and partial remissions in 75 (54.3% ) and 52 (37.7% ) cases, respectively. With a median follow-up of 24 months (range: 4–64), the progression-free survival rate was (87.5 ± 3.0) % and the overall survival rate was (83.2 ± 3.3) %. Of the 27 patients who died, 6 (22.2% ) died due to disease progression. The mean applied dose of bendamustine per cycle was 73.0 (50.8–89.7) mg/m 2 per day, administered on days 1 and 2. Adverse events of grade 3 or higher were reported in 53 (33.3% ) patients, with infection (30 cases,18.9% ) and neutropenia (24 cases, 15.1% ) demonstrating the highest incidence. Conclusion:Bendamustine combined with anti-CD20 monoclonal antibody demonstrated good efficacy and is well-tolerated in the first-line treatment of elderly patients with B-iNHL.

BACKGROUND:Mechanical alignment is the"gold standard"alignment technique in total knee arthroplasty,but regardless of advances in prosthetic materials and robotic-assisted navigation,mechanical alignment-total knee arthroplasty still has a patient dissatisfaction rate of about 20％.OBJECTIVE:To evaluate the early efficacy of navigation-assisted total knee arthroplasty using functional alignment.METHODS:A total of 44 consecutive cases(50 knees)that underwent computer navigation-assisted total knee arthroplasty with functional alignment from October 2019 to June 2023 were retrospectively analyzed,including 12 males(14 knees)and 32 females(36 knees).A total of 46 consecutive cases(50 knees)that underwent navigation-assisted total knee arthroplasty with mechanical axis alignment by the same surgical team during the same period were selected as controls,including 5 males(5 knees)and 41 females(45 knees).The tibial osteotomy angle,tibial plateau osteotomy amount,femoral osteotomy angle,distal femoral,posterior and anterior osteotomy amount,and joint line movement were observed in the two groups of patients.Preoperative and postoperative flexion and extension gap internal and external laxity,hip-knee-ankle angle,mechanical lateral distal femoral angle,mechanical medial proximal tibial angle,joint line convergence angle,sagittal femoral component angle,posterior tibial slope,arithmetic hip-knee-ankle angle,joint line obliquity,coronal plane alignment of the knee classification,Western Ontario and McMaster Universities Osteoarthritis Index,and Hospital for Special Surgery score and forgotten joint score were compared between the two groups.RESULTS AND CONCLUSION:(1)The intraoperative tibial plateau osteotomy angle in the functional alignment group was greater than that in the mechanical axis alignment group,and the proportion of gap imbalance(2％)was smaller than that in the mechanical axis alignment group(18％).The differences were all significant(P＜0.05).(2)The hip-knee-ankle angle,mechanical medial proximal tibial angle,arithmetic hip-knee-ankle angle,and joint line obliquity in the functional alignment group were smaller than those in the mechanical axis alignment group postoperatively,and the differences were significant(P＜0.05).(3)The most common coronal plane alignment of the knee classification before surgery was type Ⅰ(80％in the functional alignment group and 42％in the mechanical axis alignment group).(4)The proportion of joint line obliquity＜177°(44％)in the functional alignment group was greater than that in the mechanical axis alignment group(14％)postoperatively.(5)Hospital for Special Surgery score at 1 month,6 months,and last follow-up after surgery was higher in the functional alignment group than that in the mechanical axis alignment group;the differences were statistically significant(P＜0.05).The Western Ontario and McMaster Universities Osteoarthritis Index 1 month after surgery was lower in the functional alignment group than that in the mechanical axis alignment group;the difference was statistically significant(t=-2.85,P=0.005).There was no significant difference in postoperative range of motion and forgotten joint score between the two groups(P＞0.05).(6)It is indicated that navigation-assisted total knee arthroplasty using functional alignment optimizes early clinical efficacy.The functional alignment technique has advantages in restoration of constitutional alignment and joint line obliquity and avoids soft tissue release compared to mechanical alignment technique.

Objective:To investigate the influencing factors of the outcome in patients with asymptomatic intracranial hemorrhage (aICH) after endovascular therapy (EVT) for large vessel occlusive stroke in anterior circulation.Methods:Patients with large vessel occlusive stroke in anterior circulation underwent EVT at Dongguan People's Hospital from January 2019 to January 2023 were included retrospectively. According to the CT re-examination results within 72 hours after EVT and the changes in the National Institutes of Health Stroke Scale (NIHSS) score, the patients were divided into non-ICH group and aICH group. At 90 days after onset, the modified Rankin Scale was used to evaluate functional outcome, >2 points were defined as a poor outcome. Multivariate logistic regression analysis was used to determine the independent correlated factors for outcome. Results:A total of 173 patients who did not experience intracranial hemorrhage (ICH) or experienced aICH after EVT were enrolled, including 121 males (69.9%), median aged 64.0 years. Sixty-four patients (37.0%) developed aICH after EVT, of which 44 (68.8%) were hemorrhagic infarction (HI) and 20 (31.2%) were parenchymal hematoma (PH). The incidence of poor outcome in the ICH group was significantly higher than that in the non-ICH group (42.2% vs. 26.6%; χ2=4.472, P=0.034). In aICH patients with poor collateral circulation, the proportion of patients with poor outcome was significantly higher than in all non-ICH patients (68.7% vs. 26.6%; χ2=11.388, P<0.001), while there was no significant difference in the proportion of patients with poor outcome in the good collateral circulation group compared to all non-ICH patients (23.5% vs. 26.6%; χ2=0.072, P=0.788). In aICH patients, the proportion of PH (68.7% vs. 11.8%; χ2=14.561, P<0.001) and poor outcome (68.7% vs. 23.5%; χ2=7.209, P=0.027) in patients with poor collateral circulation were significantly higher than that of good collateral circulation. Multivariate logistic regression analysis showed that poor collateral circulation (odds ratio [ OR] 3.84; 95% confidence interval [ CI] 1.07-12.76; P=0.039), older age ( OR 1.07, 95% CI 1.02-1.11; P=0.004), unsuccessful recanalization ( OR 6.36, 95% CI 1.74-23.23; P=0.005) , and PH ( OR 6.14, 95% CI 1.83-20.58; P=0.003) were the independent risk factors for poor outcome in patients with aICH. Conclusions:Among patients who developed aICH after EVT, the proportion of patients with poor outcome in the good collateral circulation group is comparable to that in the non-ICH group, but the risks of PH and poor outcome are significantly increased in the poor collateral circulation group. Poor collateral circulation is an independent risk factor for poor outcome in patients with aICH after EVT for large vessel occlusive stroke in anterior circulation.

OBJECTIVE: To investigate the surgical technique and the short-term effectivenss of lateral unicompartmental knee arthroplasty (LUKA) through lateral approach in the treatment of valgus knee and to calculate the maximum value of the theoretical correction of knee valgus deformity. METHODS: A retrospective analysis was performed on 16 patients (20 knees) who underwent LUKA and met the selection criteria between April 2021 and July 2022. There were 2 males and 14 females, aged 57-85 years (mean, 71.5 years). The disease duration ranged from 1 to 18 years, with an average of 11.9 years. Knee valgus was staged according to Ranawat classification, there were 6 knees of type Ⅰ, 13 knees of type Ⅱ, and 1 knee of type Ⅲ. All patients were assigned the expected correction value of genu valgus deformity by preoperative planning, including the correction value of lateral approach, intra-articular correction value, and residual knee valgus deformity value. The actual postoperative corrected values of the above indicators were recorded and the theoretical maximum correctable knee valgus deformity values were extrapolated. The operation time, intraoperative blood loss, incision length, hospital stay, hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibia angle (mMPTA), joint line convergence angle (JLCA), posterior tibial slope (PTS), range of motion (ROM), Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were also recorded for effectiveness evaluation. RESULTS: The patients' incision length averaged 13.83 cm, operation time averaged 85.8 minutes, intraoperative blood loss averaged 74.9 mL, and hospital stay averaged 6.7 days. None of the patients suffered any significant intraoperative neurological or vascular injuries. All patients were followed up 10-27 months, with a mean of 17.9 months. One patient with bilateral knee valgus deformities had intra-articular infection in the left knee at 1 month after operation and the remaining patients had no complication such as prosthesis loosening, dislocation, and infection. The ROM, HSS score, and WOMAC score of knee joint significantly improved at each time point after operation when compared to those before operation, and the indicators further improved with time after operation, the differences were all significant ( P<0.05). Imaging measurement showed that HKA, mLDFA, JLCA, and PTS significantly improved at 3 days after operation ( P<0.05) except for mMPTA ( P>0.05). Postoperative evaluation of the knee valgus deformity correction values showed that the actual intra-articular correction values ranged from 0.54° to 10.97°, with a mean of 3.84°. The postoperative residual knee valgus deformity values ranged from 0.42° to 5.30°, with a mean of 3.59°. The actual correction values of lateral approach ranged from 0.21° to 12.73°, with a mean of 4.26°. CONCLUSION LUKA through lateral approach for knee valgus deformity can achieve good early effectiveness. Preoperative planning can help surgeons rationally allocate the correction value of knee valgus deformity, provide corresponding treatment strategies, and the maximum theoretical correction value of knee valgus deformity can reach 25°.
Male ; Female ; Humans ; Arthroplasty, Replacement, Knee/methods* ; Retrospective Studies ; Blood Loss, Surgical ; Osteoarthritis, Knee/surgery* ; Knee Joint/surgery*

Objective:To evaluate the distribution characteristics of postinterventional cerebral hyperdensities (PCHDs) in patients with acute anterior circulation large vessel occlusive stroke after interventional therapy using the Alberta Stroke Program Early CT Score (ASPECTS) and to investigate its predictive value for symptomatic intracranial hemorrhage (sICH).Methods:Consecutive patients with acute anterior circulation large vessel occlusive stroke underwent endovascular mechanical thrombectomy (EMT) in the Stroke Center of Dongguan People's Hospital from January 2018 to December 2020 were retrospectively enrolled. The clinical, imaging and follow-up data were collected. The immediate PCHDs-ASPECTS after endovascular therapy were analyzed. Multivariate logistic regression analysis and receiver operator characteristic (ROC) curve were used to investigate its predictive value for sICH. Results:A total of 161 patients were enrolled in the study, including 115 males (71.4%). The baseline National Institutes of Health Stroke Scale (NIHSS) score was 13.6±5.6; 66 patients (41.0%) developed PCHDs and 35 (21.7%) had sICH. The baseline NIHSS score, the proportion of patients with severe stroke, the number of retrieval attempts and the detection rate of PCHDs in the sICH group were significantly higher than those in the non-sICH group, while diffusion weighted imaging-ASPECTS and PCHDs-ASPECTS were significantly lower than those in the non-sICH group (all P<0.05). Multivariate logistic regression analysis showed that PCHDs had a significant independent positive correlation with sICH (odds ratio 6.036, 95% confidence interval 1.45-25.123; P=0.013), and PCHDs-ASPECTS had a significant independent negative correlation with sICH (odds ratio 0.70, 95% confidence interval 0.496-0.992; P=0.045). ROC analysis showed that the area under the curve predicted by PCHDs-ASPECTS was 0.832 ( P<0.05). When its cut-off value was 8 points, the sensitivity and specificity were 74.3% and 83.3% respectively. Conclusions:In patients with acute anterior circulation large vessel occlusive stroke treated with EMT, the immediate postoperative PCHDs is an independent predictor of sICH, and PCHDs-ASPECTS can early predict the risk of sICH after EMT.

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 compare the prosthesis locations and postoperative hip functions between supercapsular percutaneously-assisted total hip (SuperPATH) approach and traditional posterolateral approach (PLA) in total hip arthroplasty.Methods:A retrospective analysis was conducted of the 107 patients who had undergone unilateral total hip arthroplasty at Department of Orthopedic Surgery, The First Affiliated Hospital to Soochow University from August 2016 to February 2019. They were divided into 2 groups according to their surgical approaches. In the SuperPATH group of 54 cases, there were 20 males and 34 females with an age of (64.3±9.1) years; in the PLA group of 53 cases, there were 20 males and 33 females with an age of (62.2±10.6) years. The 2 groups were compared in terms of abduction angle, ratio of abduction angle to safety zone, anteversion angle, ratio of anteversion angle to safety zone, retroversion angle, incidence of retroversion, and differences in eccentricity and lower limb length on the first day after operation, and Harris hip scores at 1 week, 3 months and the last follow-up postoperatively. Their complications were also recorded as well.Results:There were no statistically significant differences in the preoperative general data between the 2 groups, showing comparability ( P>0.05). The postoperative imaging data were complete for the 107 patients who had been followed up satisfactorily for 14 to 36 months (average, 25 months). The SuperPATH group had significantly larger retroversion angle (13.6°±9.6°) and incidence of retroversion (18.5%, 10/54), significantly smaller difference in eccentricity [0.26 (0.13,0.49) cm], and significantly higher Harris hip score [(74.8±7.8) points] at one week after surgery than those in the PLA group [3.0°±1.0°; 5.7%, 3/53; 0.38 (0.13,0.70) cm; (72.0±6.7) points] ( P<0.05). There were no statistically significant differences between the 2 groups in abduction angle, ratio of abduction angle to safety zone, anteversion angle, ratio of anteversion angle to safety zone, difference in lower limb length, or Harris hip scores at 3 months or the last follow-up postoperatively (all P>0.05). Follow-ups in both groups observed no more than one case of dislocation which responded to manual reduction. Conclusion:The minimally invasive SuperPATH approach may obtain better femoral eccentricity and higher early hip function scores than the traditional posterolateral approach, but may lead to a higher incidence of retroversion after prosthesis placement.

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.