Surgical robots, as a new means for surgeons, have been gradually applied in orthopedics. Initially, the development of orthopedic robots was stagnant for a long time because of limited techniques available, clumsy equipment, high costs, and low market demands. The recent decade has witnessed rapid growth of artificial intelligence in all walks of life, increasing investment in research and development, reducing manufacture costs and expanding demands for precise and individualized medical treatment so that a wide variety of novel and ingenious robotic systems have been proposed, prototyped, and commercialized in most of the major procedures in orthopedic surgery, including knee and hip replacements, cruciate ligaments surgery, spine surgery, corrective osteotomy, bone tumor surgery, and trauma surgery. This review depicts the history of development and future prospects in application of surgical robots in the field of orthopedics.

Objective:To investigate the outcomes of periacetabular osteotomy (PAO) through modified Smith-Petersen or Bikini approach with an auxiliary posterolateral incision for developmental dysplasia of hip (DDH).Methods:85 patients (97 hips) who underwent PAO through modified Smith-Petersen or Bikini approach with auxiliary posterolateral incision for DDH in the 920th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army or the Second Xiangya Hospital of Central South University from January 2016 to January 2021 were retrospectively analyzed. There were 70 females and 15 males, with an average age of 28.6±8.4 years (12-49). According to the Hartofilakidis classification, all patients were classified as type Ⅰ. There were 77 hips classified as Grade 0 and 20 hips classified as Grade 1 according to the T?nnis classification. The X-ray evaluation including the lateral central edge angle (LCEA), t?nnis angle (TNS) and anterior central edge angle (ACEA), visual analogue score (VAS) and modified Harries hip score (mHHS) were recorded preoperatively and during each postoperative follow-up. The cumulative sum (CUSUM) method was used to fit the learning curves of operation time.Results:All patients were followed-up with an average of 52.7±18.9 months (21 to 84). The average operative time and intraoperative blood loss were 95.9±28.2 min (65 to 215) and 414.7±97.0 ml (250 to 900), respectively. The learning curve of operation time was 10 cases. The average LCEA 32.39° (30.29°, 34.92°), TNS 3.14° (1.56°, 5.67°) and ACEA 31.55° (29.07°, 33.88°) were all significantly improved compared to preoperative values ( Z=-30.764, P<0.001; Z=30.595, P<0.001; Z=-38.134, P<0.001). The average VAS was reduced from 5.18±0.88 points preoperatively to 1.27±0.93 points postoperatively with significant difference ( t=51.231, P<0.001). The average mHHS was increased from 73.12±9.17 to 92.02±4.05 postoperatively with significant difference ( t=-26.902, P<0.001). No patients received total hip arthroplasty during the follow-up period. Conclusion:Bernese PAO through modified Smith-Petersen or Bikini approach with a small auxiliary posterolateral incision was not only a safe and effective method for the treatment of DDH but also shortened the learning curve and reduced difficulty of the surgery.

Objective To observe the clinical effects of arthroscopic reconstruction for anterior cruciate ligament ( ACL ) tear using tension-relieving technique and enhanced recovery after surgery ( ERAS ) . Methods Between May 2014 and June 2016, 80 patients with ACL tear were randomly di-vided into 2 equal groups. The experimental group was treated with arthroscopic reconstruction using hamstring tendon autograft and tension-relieving technique followed by ERAS; the control group was treated with arthroscopic reconstruction using hamstring tendon autograft only followed by conventional postoperative re-covery. The 2 groups were compared in terms of knee flexion angles at postoperative 2nd, 4th and 8th weeks, and the IKDC ( International Knee Documentation Committee ) , HSS ( Hospital for Special Surgery ) , and Lysholm scores at postoperative 3rd, 6th and 12th months. Results The 80 patients obtained an average follow-up of 12. 3 ± 1. 7 months. Arthroscopy one year postoperation revealed fine ACL growth without laxity or other complications in the experimental group. Joint stiffness appeared in one case at 2 months postoperation and ACL laxity was observed in 3 cases by arthroscopy at 12 months postoperation in the control group. The knee flexion angles at postoperative 2nd, 4th and 8th weeks, and the IKDC, HSS and Lysholm scores at postoperative 3rd, 6th and 12th months in the experimental group were significantly better than those in the control group ( P <0. 05 ) . In both groups, the IKDC, HSS and Lysholm scores at postoperative 3rd, 6th and 12th months and the knee flexion angles at postoperative 2nd, 4th and 8th weeks were all significantly im-proved than the preoperative values ( P <0. 05 ) . Conclusion In arthroscopic reconstruction for ACL tear, tension-relieving technique combined with ERAS can promote functional recovery of the knee and reduce postoperative complications, facilitating early recovery of sports function.

Objective To explore stress changes of articular surface of knees after unicompartmental knee arthroplasty (UKA) using the finite element analysis,so as to make clear the advantages and disadvantages of such a surgery.Methods Dynamic finite element analysis was performed for 6 patients after UKA and 6 healthy subjects,and compared with previous analysis of patients undergoing total knee arthroplasty (TKA).Results The stress of medial compartment was significantly bigger than that of the lateral of normal knees when bending to 30° (P＜0.05).It was the same case for postoperative knees of TKA in the whole flexion movement and those of UKA at the bending angle of 0°,60° and 90° (P＜ 0.05 for both).At the bending angle of 60° and 90°,the stress of the medial compartment of postoperative UKA knees was significantly bigger than that of the TKA knees and in the whole flexion movement,the stress of the lateral compartment of the former was significantly bigger than the latter,The stress of lateral compartment of postoperative UKA knees was bigger than the normal controls at the bending angle of 0°,30°,60° and 120° (P＜0.05).Conclusion UKA may increase the stress of knee joints and accelerate the development of osteoarthritis of the contralateral compartment,leading to poor long-term effect.However,the surgery still has advantages if strictly choosing surgery indications,optimizing the surgical operations,properly improving prosthesis and reasonably guiding patients rehabilitation.

Objective:To investigate the short-term efficacy of rotational femoral neck osteotomy with preservation of the round ligament in the treatment of subchondral insufficiency fracture of the femoral head (SIFFH) in young and middle-aged people.Methods:A retrospective case series study was used to analyze the clinical data of 13 patients with SIFFH, who were admitted to 920th Hospital of Joint Logistics Support Force from January 2017 to January 2022. The patients included 10 males and 3 females, aged 22-49 years [(33.5±8.3)years]. There were 6 patients with fracture on the left hip and 7 on the right hip. All the patients were treated by rotational femoral neck osteotomy with preservation of the round ligament. Postoperatively, standardized joint functional training was given. The operative time and intraoperative bleeding were recorded. The modified Harris hip score and visual analogue score (VAS) were compared preoperatively, at 3, 6 months postoperatively and at the final follow-up. Radiological examinations were used to observe the occurrence of any collapse of the femoral head, non-union at osteotomy site or other complications.Results:The patients were followed up for 13-24 months [(17.9±3.1)months]. The operative time was (127.3±9.8)minutes, with the intraoperative bleeding of (393.9±21.9)ml. The values of modified Harris hip score were (61.6±3.3)points, (80.2±4.4)points, and (91.9±4.1)points at 3, 6 months postoperatively and at the final follow-up, respectively, being significantly higher than the preoperative (51.4±3.5)points (all P<0.05), and there were significant differences between different postoperative timepoints (all P<0.05). The values of VAS were (4.9±1.1)points, (3.0±0.9)points, and (1.4±0.5)points at 3, 6 months postoperatively and at the final follow-up, respectively, being significantly lower than preoperative (6.7±0.9)points (all P<0.05), and there were significant differences between different postoperative timepoints (all P<0.05). Imaging examination showed no femoral head collapse, with all the bones healed at the osteotomy site. There were no serious complications such as bone non-union, incision infection or peripheral nerve injury. Conclusion:Rotational femoral neck osteotomy with preservation of the round ligament in treating SIFFH in the young and middle-aged population has the advantages of shortened operative time, less intraoperative bleeding, promoted hip function recovery, attenuated pain and decreased complications, showing a satisfactory early effect.

Objective:To investigate the early curative effects of robot-assisted total knee arthroplasty (TKA) in the treatment of valgus knee.Methods:A retrospective study was conducted to analyze the data of 40 patients with valgus knee who had been treated by TKA at Department of Orthopaedics, The 920th Hospital of Joint Logistics Support Force of Chinese People's Liberation Army from January to December 2021. The patients were divided into 2 groups according to whether a robot had been used or not for TKA. In the observation group of 15 cases for which TKA was assisted by a robot, there were 4 males and 11 females with an age of (65.5±6.2) years, and the disease course was 42 (36, 54) months; in the control group of 25 cases for which conventional TKA was performed, there were 8 males and 17 females with an age of (65.8±7.5) years, and the disease course was 42 (36, 60) months. Surgical time, hemoglobin decrease, and knee joint range of motion, American Knee Society Score (KSS), hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) at 12 months after surgery were compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, indicating comparability ( P>0.05). The surgical time in the observation group was (148.0±21.2) min, significantly longer than that in the control group [(115.2±7.1) min], and the hemoglobin decreased by (11.8±1.1) g/L in the observation group, significantly less than that in the control group [(18.1±1.8) g/L] ( P<0.05). The observation group and the control group were followed up for 13 (13, 14) and 13 (13, 14) months after surgery, respectively, showing no statistically significant difference ( P>0.05). At 12 months after surgery, the KSS knee score, KSS functional score, and knee range of motion in the observation group were (86.1±4.6) points, (86.9±3.1) points, and 115.7°±5.0°, significantly larger than those in the control group [(82.2±3.5) points, (82.8±0.9) points, and 108.2°±5.0°] ( P<0.05). Reexamination of full-length radiographs of both lower limbs in all patients showed good positions of the prostheses and no such adverse events as loosening or sinking at 12 months after surgery. The HKA (178.5°±1.2°) and LDFA (89.1°±0.7°) at 12 months after surgery in the observation group were significantly larger than those in the control group (176.6°±1.5°, 88.2°±8.2°) ( P<0.05); there was no statistically significant difference in MPTA between the 2 groups ( P>0.05). Conclusions:In the treatment of valgus knee, robot-assisted TKA can correct joint deformity, and achieve precise osteotomy and functional alignment of lower limbs, leading to better early curative effects than conventional TKA.

Objective:To investigate the safety and effectiveness of robot-assisted total knee arthroplasty (TKA).Methods:From August 2021 to March 2022, the data of 69 patients who received robot-assisted TKA for inflammatory disease of knee in 6 hospitals were collected, including 24 males and 45 females, aged 52±6 years (range, 46-72 years), including 53 cases of knee osteoarthritis,10 cases of rheumatoid arthritis, and 6 cases of traumatic arthritis. Imaging data examination of patients was completed according to the multicenter specification. Preoperatively, the patient's CT data were extracted before surgery and a personalized prosthesis positioning plan was designed by the robotic system to determine the prosthesis size, lower limb force lines, and femoral and tibial osteotomy volumes; intraoperatively, the osteotomy template was robotically controlled to complete the osteotomy according to the prosthesis positioning plan, and the intraoperative osteotomy volumes were measured to verify the accuracy of the robot-assisted TKA osteotomy with the preoperative planning. Postoperatively, the lateral angle of the distal femur, the medial angle of the proximal tibia and the hip-knee-ankle angle were measured in the coronal plane according to radiographs; the postoperative outcome was evaluated 3 months after operation, using the American Knee Society score (KSS), including the KSS knee score and functional score.Results:The operative time was 97.3±2.3 min (range, 80-110 min) and the amount of bleeding was 320.0±6.2 ml (range, 300-350 ml) in 69 patients. Three months after operation, the mean range of motion of knee joint was increased from 82.2°±1.1° before surgery to 119.7°±0.8° after surgery ( t=27.65, P<0.001), and the line of force of lower limb was improved from 160.9°±0.5° before surgery to 178.0°±0.2° after surgery ( t=32.03, P<0.001). KSS-knee score increased from 54.8±0.7 points before operation to 85.0±0.5 points after operation, and KSS-functional score increased from 56.5±0.7 points before operation to 85.9±0.4 points after operation, the difference was statistically significant ( t=35.45, 36.58, P<0.001). The proportion of patients with intraoperative femoral and tibial osteotomies within 2 mm osteotomy error compared with preoperative planning was 97% for the lateral tibial plateau, 100% for the medial tibial plateau, 100% for the lateral distal femur, 99% for the medial distal femur, 93% for the lateral posterior femoral condyle, and 100% for the medial posterior femoral condyle; The proportion of patients with postoperative anteroposterior X-ray measurement angle error within 3° was: 100.0% for the distal lateral femoral angle, 100.0% for the proximal medial tibial angle, and 100% for the hip-knee-ankle angle. No complications occurred in all patients except for one case in which fat liquefaction occurred in the postoperative wound. Conclusion:Robot-assisted TKA is a safe and effective surgical method for the treatment of inflammatory disease of knee with accurate prosthesis installation and good postoperative recovery of lower limb alignment.

Objective:To investigate the mid-and long-term clinical efficacy of modified Colonna arthroplasty in the treatment of unilateral dislocation type developmental dysplasia of hip (DDH) in adolescents.Methods:A total of 28 adolescent DDH patients with unilateral dislocation who underwent modified Colonna capsular arthroplasty from January 2016 to January 2018 in the 920th Hospital of Joint Logistics Support Force of People's Liberation Army were retrospectively analyzed. There were 4 males and 24 females, aged 16.5±5.0 years (range, 10-25 years). The mean body mass index was 21.2±1.1 kg/m 2 (range, 18.7-24.1 kg/m 2). According to DDH classification, 10 cases were Tonnis type III and 18 cases were Tonnis type IV. The postoperative lateral center-edge angle, acetabular coverage, femoral anteversion angle and leg length discrepancy were measured. The operation time, intraoperative blood loss, visual analogue scale (VAS) of hip pain, Harris hip score (HHS) and congenital dislocation of the hip score were recorded. Results:All patients successfully completed the operation and were followed up for 72.1±5.2 months (range, 60-84 months). The operation time was 81.6±4.3 min (range, 70-90 min), the intraoperative blood loss was 177.5±12.6 ml (range, 160-200 ml), and the hospital stay was 6.8±0.7 days (range, 6-9 days). The VAS score of the hip joint was 1.8±0.6 before operation and 2.3±0.6 at the last follow-up, and the difference was not statistically significant ( t=2.845, P=0.224). The preoperative HHS score was 57.1±5.9, and it increased to 87.3±4.0 at the last follow-up, and the difference was statistically significant ( t=-22.141, P=0.001). At the last follow-up, the femoral anteversion angle was 17.0°±1.5°, which was lower than that before operation 41.6°±2.4°, with a statistically significant difference ( t=-44.868, P=0.008). The leg length discrepancy was 10.2±2.3 mm, which was lower than that before operation (26.4±6.1 mm), with a statistically significant difference ( t=-12.892, P<0.001). The lateral center-edge angle was 28° (26°, 30°), and the acetabular coverage rate was 78% (76%, 79%). The curative effect evaluation standard score of congenital dislocation of the hip was 24 (16.7, 25.7) points, including 7 excellent cases, 14 good cases, 4 fair cases, and 3 poor cases. The excellent and good rate was 75% (21/28). Conclusion:The modified Colonna arthroplasty for the treatment of unilateral dislocation DDH in adolescents has good mid-and long-term hip function recovery and radiographic improvement.