Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Objective:To compare the mid- to long-term clinical outcomes of arthrolysis versus revision arthroplasty for arthrofibrosis-related stiffness following total knee arthroplasty (TKA).Methods:A retrospective analysis was conducted of the 20 patients (26 knees) with post-TKA arthrofibrosis who had been treated at Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital between January 2004 and January 2020. The patients were divided into 2 groups based on their treatment: an arthrolysis group of 8 cases (10 knees) [1 male (2 knees)and 7 females (8 knees); median age: 44.0 (21.0, 62.0) years] and a revision arthroplasty group of 13 cases (16 knees) [4 males (6 knees)and 9 females (10 knees); median age: 41.5 (30.0, 56.0) years]. The knee range of motion (ROM) and the American Hospital for Special Surgery (HSS) knee score as well as their improvements were compared between preoperation and the last follow-up, as well as between the 2 groups; the satisfaction of the patients at the last follow-up was compared between the 2 groups.Results:No significant differences in the baseline characteristics were observed between the 2 groups, indicating comparability ( P>0.05). The preoperative knee ROM [55.0° (48.8°, 61.3°)] and HSS knee score [54.0 (47.0, 61.8) points] in the arthrolysis group were significantly higher than those in the revision group [27.5° (6.3°, 50.0°), 33.0 (27.3, 47.8) points] ( P<0.05). In the arthrolysis and revision arthroplasty groups, the knee ROMs [90.0° (65.0°, 100.0°), 90.0° (63.5°, 98.8°)] and HSS knee scores [(69.8±19.9) points, (77.6±11.3) points] at the last follow-up were significantly improved compared with those before operation ( P<0.05). In the revision arthroplasty group, the improvement in knee ROM (48.9°±21.7°) was insignificantly larger than that in the arthrolysis group (34.5°±13.2°) ( P>0.05), but the improvement in HSS knee score [39.5 (25.3, 57.0) points] was significantly larger than that in the arthrolysis group [16.0 (10.5, 25.3) points] ( P<0.05). Respectively, 14 and 3 knees in the revision arthroplasty group and the arthrolysis group resulted in patient satisfaction, showing a significant difference between the 2 groups ( P<0.05). Conclusions:Both arthrolysis and revision arthroplasty can significantly improve knee ROM and HSS knee score in post-TKA arthrofibrosis. However, since revision arthroplasty demonstrates superior improvements in HSS knee score and patient satisfaction, it is preferable for patients with lower preoperative knee ROM.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Objective:To compare the mid- to long-term clinical outcomes of arthrolysis versus revision arthroplasty for arthrofibrosis-related stiffness following total knee arthroplasty (TKA).Methods:A retrospective analysis was conducted of the 20 patients (26 knees) with post-TKA arthrofibrosis who had been treated at Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital between January 2004 and January 2020. The patients were divided into 2 groups based on their treatment: an arthrolysis group of 8 cases (10 knees) [1 male (2 knees)and 7 females (8 knees); median age: 44.0 (21.0, 62.0) years] and a revision arthroplasty group of 13 cases (16 knees) [4 males (6 knees)and 9 females (10 knees); median age: 41.5 (30.0, 56.0) years]. The knee range of motion (ROM) and the American Hospital for Special Surgery (HSS) knee score as well as their improvements were compared between preoperation and the last follow-up, as well as between the 2 groups; the satisfaction of the patients at the last follow-up was compared between the 2 groups.Results:No significant differences in the baseline characteristics were observed between the 2 groups, indicating comparability ( P>0.05). The preoperative knee ROM [55.0° (48.8°, 61.3°)] and HSS knee score [54.0 (47.0, 61.8) points] in the arthrolysis group were significantly higher than those in the revision group [27.5° (6.3°, 50.0°), 33.0 (27.3, 47.8) points] ( P<0.05). In the arthrolysis and revision arthroplasty groups, the knee ROMs [90.0° (65.0°, 100.0°), 90.0° (63.5°, 98.8°)] and HSS knee scores [(69.8±19.9) points, (77.6±11.3) points] at the last follow-up were significantly improved compared with those before operation ( P<0.05). In the revision arthroplasty group, the improvement in knee ROM (48.9°±21.7°) was insignificantly larger than that in the arthrolysis group (34.5°±13.2°) ( P>0.05), but the improvement in HSS knee score [39.5 (25.3, 57.0) points] was significantly larger than that in the arthrolysis group [16.0 (10.5, 25.3) points] ( P<0.05). Respectively, 14 and 3 knees in the revision arthroplasty group and the arthrolysis group resulted in patient satisfaction, showing a significant difference between the 2 groups ( P<0.05). Conclusions:Both arthrolysis and revision arthroplasty can significantly improve knee ROM and HSS knee score in post-TKA arthrofibrosis. However, since revision arthroplasty demonstrates superior improvements in HSS knee score and patient satisfaction, it is preferable for patients with lower preoperative knee ROM.

Objective:To analyze three reconstruction techniques and mid-term clinical outcomes of hip revision for acetabular bone defect after total hip arthroplasty (THA).Methods:This is a retrospective case series study. Included in the study were 109 patients (109 hips) with acetabular bone defect after THA reconstructions in hip revisions from January 2015 to December 2021 in the Senior Department of Orthopaedics, the Forth Medical Center of Chinese People′s Liberation Army General Hospital and the Department of Orthopaedics, the First Medical Center of Chinese People′s Liberation Army General Hospital. According to the preoperative simulated surgeries and different bone defect reconstruction techniques, patients were divided into a normal cup group, an augment group or a triflange group,respectively. There were 54 patients (54 hips) in the normal cup group, reconstructed with the uncemented porous metal cup (including Jumbo cup), with 23 males and 31 females, aged (59.6±9.9) years (range:32 to 76 years); 44 patients (44 hips) in the augment group, reconstructed with the individualized three-dimensional (3D) printed porous metal augment and uncemented porous metal cup, with 18 males and 26 females, aged (52.8±13.6) years(range:17 to 76 years); 11 patients (11 hips) in the triflange group, reconstructed by the individualized 3D printed porous metal triflange cup, with 5 males and 6 females, aged (59.4±11.2) years (range: 43 to 78 years). Radiographic results, including rotation center height, rotation center offset, and leg length discrepancy (LLD) and clinical results, including Harris hip score (HHS) and visual analogue scale(VAS) were evaluated outpatient at 3, 6, 12 months after the operation and annually thereafter. The last follow-up was completed in March 2024, and all parameters at the last follow-up and before the operation were compared. Paired sample t test and repeated measurement ANOVA were used for the radiographic and clinical parameters before and after the operation. Results:All hip revisions for patients with acetabular bone defect after THA were completed and followed for more than two years. The follow-up time of the normal cup group was (6.5±1.7) years (range: 2.8 to 9.3 years), and that of the augment group was (6.0±1.3) years (range: 3.5 to 9.0 years). The follow-up time of the triflange group was (2.8±0.6) years (range: 2.0 to 3.8 years). At the last follow-up, the rotation center height, rotation center offset and LLD of 54 hips in the normal cup group were (24.2±5.6) mm, (29.1±5.5) mm and (4.6±3.3) mm, respectively, and the rotation center height and LLD were significantly lower than those of the preoperative hips ( t=9.671, P<0.01; t=6.073, P<0.01). In the augment group, the rotational center height, the rotation center offset and the LLD of 44 hips were (22.4±9.0) mm, (25.4±5.5) mm and (6.0±4.0) mm, respectively, which were significantly lower than those of the preoperative hips ( t=9.071, P<0.01; t=11.345, P<0.01; t=4.927, P<0.01). In the triflange group, the rotational center height, the rotation center offset and LLD of 11 hips were (22.7±6.0) mm,(30.9±8.0) mm and (5.3±2.2) mm, respectively, and the rotation center height and LLD were significantly lower than those of the preoperative hips ( t=2.716, P=0.022; t=6.226, P<0.01). At the last follow-up, fractures occurred in 3 patients and dislocation occurred in 1 patient in the normal cup group, and fracture reduction and closed reduction were administered under anesthesia, respectively. In the augment group, dislocation occurred in 1 patient and open reduction under anesthesia was performed. The HHS and VAS of the three groups improved significantly after surgery and the differences were statistically significant (all P<0.01). There was no complication in the triflange group. The X-ray at the last follow-up showed that all prostheses and augments were in stable positions and no loosening or migration was observed. Conclusions:For patients with acetabular bone defect after THA undergoing hip revisions, preoperative surgical simulation and rehearsal could help surgeons choose convenient and efficient reconstruction techniques. The targeted selection of Jumbo cup, individualized 3D printed metal augment, and customized triflange cup could achieve satisfactory clinical outcomes.

Objective:To analyze three reconstruction techniques and mid-term clinical outcomes of hip revision for acetabular bone defect after total hip arthroplasty (THA).Methods:This is a retrospective case series study. Included in the study were 109 patients (109 hips) with acetabular bone defect after THA reconstructions in hip revisions from January 2015 to December 2021 in the Senior Department of Orthopaedics, the Forth Medical Center of Chinese People′s Liberation Army General Hospital and the Department of Orthopaedics, the First Medical Center of Chinese People′s Liberation Army General Hospital. According to the preoperative simulated surgeries and different bone defect reconstruction techniques, patients were divided into a normal cup group, an augment group or a triflange group,respectively. There were 54 patients (54 hips) in the normal cup group, reconstructed with the uncemented porous metal cup (including Jumbo cup), with 23 males and 31 females, aged (59.6±9.9) years (range:32 to 76 years); 44 patients (44 hips) in the augment group, reconstructed with the individualized three-dimensional (3D) printed porous metal augment and uncemented porous metal cup, with 18 males and 26 females, aged (52.8±13.6) years(range:17 to 76 years); 11 patients (11 hips) in the triflange group, reconstructed by the individualized 3D printed porous metal triflange cup, with 5 males and 6 females, aged (59.4±11.2) years (range: 43 to 78 years). Radiographic results, including rotation center height, rotation center offset, and leg length discrepancy (LLD) and clinical results, including Harris hip score (HHS) and visual analogue scale(VAS) were evaluated outpatient at 3, 6, 12 months after the operation and annually thereafter. The last follow-up was completed in March 2024, and all parameters at the last follow-up and before the operation were compared. Paired sample t test and repeated measurement ANOVA were used for the radiographic and clinical parameters before and after the operation. Results:All hip revisions for patients with acetabular bone defect after THA were completed and followed for more than two years. The follow-up time of the normal cup group was (6.5±1.7) years (range: 2.8 to 9.3 years), and that of the augment group was (6.0±1.3) years (range: 3.5 to 9.0 years). The follow-up time of the triflange group was (2.8±0.6) years (range: 2.0 to 3.8 years). At the last follow-up, the rotation center height, rotation center offset and LLD of 54 hips in the normal cup group were (24.2±5.6) mm, (29.1±5.5) mm and (4.6±3.3) mm, respectively, and the rotation center height and LLD were significantly lower than those of the preoperative hips ( t=9.671, P<0.01; t=6.073, P<0.01). In the augment group, the rotational center height, the rotation center offset and the LLD of 44 hips were (22.4±9.0) mm, (25.4±5.5) mm and (6.0±4.0) mm, respectively, which were significantly lower than those of the preoperative hips ( t=9.071, P<0.01; t=11.345, P<0.01; t=4.927, P<0.01). In the triflange group, the rotational center height, the rotation center offset and LLD of 11 hips were (22.7±6.0) mm,(30.9±8.0) mm and (5.3±2.2) mm, respectively, and the rotation center height and LLD were significantly lower than those of the preoperative hips ( t=2.716, P=0.022; t=6.226, P<0.01). At the last follow-up, fractures occurred in 3 patients and dislocation occurred in 1 patient in the normal cup group, and fracture reduction and closed reduction were administered under anesthesia, respectively. In the augment group, dislocation occurred in 1 patient and open reduction under anesthesia was performed. The HHS and VAS of the three groups improved significantly after surgery and the differences were statistically significant (all P<0.01). There was no complication in the triflange group. The X-ray at the last follow-up showed that all prostheses and augments were in stable positions and no loosening or migration was observed. Conclusions:For patients with acetabular bone defect after THA undergoing hip revisions, preoperative surgical simulation and rehearsal could help surgeons choose convenient and efficient reconstruction techniques. The targeted selection of Jumbo cup, individualized 3D printed metal augment, and customized triflange cup could achieve satisfactory clinical outcomes.

Based on the analysis of heart rate variability(HRV),a prediction method for paroxysmal atrial fibrillation(PAF)attacks is proposed.A new adaptive filtering technique is used for smoothing and coarse graining of HRV,followed by entropy-based quantification of HRV complexity at multiple adaptive scales.After the features are normalized by Min-Max,feature subsets are selected by sequential forward selection method,and then input to support vector machine to identify HRV types and predict PAF attacks.Through 5-fold cross-validation on a set of 50 HRV sequences each lasting 5 minutes,the optimal prediction results are obtained:98%accuracy,100%sensitivity,96%specificity,demonstrating excellent performance.In addition,the experiment shows significant changes(P<0.05)in the complexity eigenvalues of HRV far away from and close to PAF at different frequency bands,reflecting alterations in nervous system regulation of cardiac rhythm and a decline in the ability to adapt to external environmental changes such as stress regulation.

Femoral neck fracture (FNF) in the elderly patients is currently a major health challenge worldwide, with excessive consumption of medical resources, high incidence of complications as well as suboptimal outcome and prognosis. Hip joint arthroplasty (HJA) has been the mainstream treatment for FNF in the elderly, but the conventional surgical approaches and techniques are still confronted with a series of bottlenecks such as dislocation, limp and limb length discrepancy. In recent years, direct anterior approach (DAA) for HJA (DAA-HJA) has been a major new choice in the field of joint replacement, which achieves improved clinical effectiveness of HJA in the treatment of elderly FNF, due to the fact that DAA approach involves the neuromuscular interface and accords with the idea of soft tissue retention and enhanced recovery after surgery. However, there is still a lack of unified understanding of standard technique and procedure of DAA-HJA in the treatment of elderly FNF. Therefore, relevant experts from the Hip Joint Group of Chinese Orthopedics Association of Chinese Medical Association, Youth Arthrology Group of Orthopedic Committee of PLA, Orthopedic Committee of Chongqing Medical Association, Branch of Orthopedic Surgeons of Chongqing Medical Doctor Association and Sport Medicine Committee of Chongqing Medical Association were organized to formulate the " Chinese expert consensus on the technical standard of direct anterior hip arthroplasty for elderly femoral neck fracture ( version 2023)" based on evidence-based medicine. This consensus mainly proposed 13 recommendations covering indications, surgical plans, prosthesis selections, surgical techniques and processes, and postoperative management of DAA-HJA in elderly patients with FNF, aiming to promote standardized, systematic and patient-specific diagnosis and treatment to improve the functional prognosis of the patients.

Objective:To explore the impact of robot assisted total hip arthroplasty (THA) on the accuracy of prosthesis placement and its clinical efficacy.Methods:A total of 432 patients (549 hips) who underwent robot-assisted primary THA for various diseases of the hip in the Department of Orthopaedics of the Fourth Medical Center of the PLA General Hospital from August 2018 to October 2022 was retrospectively analyzed. There were 174 male and 258 female with an average age of 54.2±12.7 years old and body mass index (BMI) of 23.2±4.3 kg/m 2. There were 301 left hips and 248 right hips. All patients were operated under general anesthesia using the standard posterior lateral surgical approach to THA. The Harris hip score (HHS), forgotten joint score (FJS), the Western Ontario and McMaster University (WOMAC) osteoarthritis index and patient satisfaction were used to evaluate the clinical outcomes. The anterior inclination, abduction angle, lower extremity discrepancy and the position of the center of rotation (COR) of the hip joint were radiographically accessed preoperatively, intraoperatively and postoperatively. The composition ratio of the acetabular cup in the safe zone was also calculated. Results:Five hundred and forty-nine consecutive hips (432 patients) underwent robotic-assisted THA with a mean follow-up of 23.6±16.2 months. The mean operative time was 86.2±35.4 min, and the mean blood loss was 236.7±94.5 ml. At the last follow-up, the mean HHS score for this group was 91.4±15.4, the WOMAC score was 8.4±6.5, the FJS score was 77.4±23.4, and the satisfaction score was 9.1±2.7 points. The mean postoperative measurement of acetabular cup anteversion was 21.2°±4.8° and abduction was 40.8°±4.3°. About 93.7% (511 patients) had an acetabular cup within the safety zone of ±10° of the target angle, and 84.6% (464 patients) had an acetabular cup within the safety zone of ±5° of the target angle. A total of 4 complications occurred. Acute periprosthesis infection happened in a case of developmental dysplasia of the hip (DDH) and was cured by DAIR (debridement, antibiotics, irrigation, retention of prosthesis). One case of thigh pain of unknown reason was treated with a revision operation, during which no loosening or malposition of the prosthesis was found. After replacing the femoral head component no pain was complained by the patient. One case of hematoma and nerve compression was considered to be caused by blood vessels injury when a titanium cable was used to fix the distal femoral fracture during the surgery. The nerve injury returned to normal within 1 month. One case of dislocation happened immediately after surgery and was revised by replacing a different head. The patient was fully recovered. In addition to software and mechanical failures of the robot itself, complex hip joint diseases would be a risk factor for the termination of robot assisted surgery due to the occurrence of adverse events related to robots in 16 hips. Considering the existence of a certain termination rate in robot assisted surgery, sufficient preparation should be made when applying robot assisted technology in complex hip joint diseases.Conclusion:In robotic-assisted THA, preoperative planning can be achieved with precise and reproducible acetabular cup positions, significantly increasing the chance of locating the acetabular cups in the safety zone, and obtaining satisfactory results in restoring COR and leg length.

Objective:To explore the learning curve of MAKO-assisted total knee arthroplasty.Methods:From May 2021 to September 2022, 136 patients were conducted MAKO-assisted total knee arthroplasty in the PLA General Hospital, including 37 males and 99 females, 65.53±7.01 years old (range 54-80 years). All cases were patients with unilateral knee osteoarthritis. The operations were performed by three surgeons, respectively. Sixty-one cases were performed by surgeon 1, 47 cases were performed by surgeon 2, and 28 cases were performed by surgeon 3. Record the time of each step during the operation, and measure the limb alignment in X-ray. The statistical difference between the two groups was compared by t test by SPSS. The cumulative sum control chart (CUSUM) learning curve was modeled by curve fitting and R2 was used to testify the goodness. Results:The total operation time of the three surgeons was 114.3±25.1 min, 109.8±10.9 min, and 118.6±15.1 min, respectively. The time of each step in the first 10 cases and the last 10 cases of operator 1-3 was counted. The osteotomy time of surgeons 1, 2 and 3 in the final 10 cases was less than that in the initial 10 cases (surgeon 1: 13.5 ± 3.41 min vs. 8.0±1.58 min, t=4.30, P=0.001; surgeon 2: 13.7±3.02 min vs. 8.0± 2.58 min, t=4.77, P=0.001; surgeon 3: 15.3±3.97 min vs. 11.0±2.38 min, t=2.87, P=0.010), and the difference was statistically significant. The CUSUM of osteotomy was calculated and the curve was fitted. The highest point of the curve of the three surgeons was in the 16th, 18th and 12th patients, respectively, and the time of osteotomy continued to decline after passing the peak. No statistical differences were found in surgery time for the remaining steps. Comparing the lower alignment angles of intraoperative planning and postoperative X-ray films, the overall difference was greater than 1 degree. The difference was 1.41°±1.32° for operator 1, 1.34°±1.22° for operator 2, and 1.04°±0.88° for operator 3. The percentages of fully accurate implant size planning were 85.2%(52/61), 76.7%(36/47), and 85.7%(24/28), respectively. Conclusion:For MAKO-assisted total knee arthroplasty, the operator can decrease the operation time by practice, which is mainly reflected in the shortening of the osteotomy time. The learning curve threshold is around in the 15th case. The increase in the number of surgeries did not bring about changes in the accuracy of lower extremity alignment.