To observe the effect of the domestic orthopedic robot-assisted core decompression and bone grafting surgery for early necrosis of the femoral head.

A retrospective analysis was performed on 36 cases underwent core decompression and bone grafting for early necrosis of the femoral head treated at Department of Bone and Joint Surgery, the Second Affiliated Hospital of Xi ′an Jiaotong University from June 2020 to May 2021. 15 cases underwent robot-assisted surgery, and 21 cases underwent conventional surgery. All the patients were in Association research circulation osseous (ARCO)stageⅡ. The operating times, the number of guidewire attempts and total number of intraoperative radiation exposure were recorded. The preoperative and postoperative Harris scores and VAS scores in three and six months were compared. The repeated measurements analysis of variances and t test of two independent samples were used for statistical analysis.

All the patients were successfully followed up, and the operation time of the robot-assisted group (57.3±18.9) min was significantly shorter than that of the traditional group (71.6±18.2) min (t=2.292, P<0.05); compared with the traditional group, the number of guidewire attempts, the total number of intraoperative radiation exposure, and the number of radiation exposure during insertion of guidewire were significantly reduced in the robot-assisted group (t=6.818, 4.871, 4.546, all P<0.05), and there were no significant differences between the two groups in Harris score and VAS score at three and six months postoperatively (F=0.080, 0.069, both P>0.05).

It is safe and effective to use the domestic robot-assisted core decompression and bone grafting for the treatment of early femoral head necrosis, which can save the operation time and reduce the radiation exposure.

To investigate the possible risk factors for anterior knee pain syndrome (AKP) after the anterior cruciate ligament reconstruction (ACLR) based on multivariate logistic regression analysis and musculoskeletal ultrasound (MSKUS).

A retrospective case-control study was conducted to analysis patients who underwent anterior cruciate ligament reconstruction (ACLR) in the Second Affiliated Hospital of Xi’an Jiaotong University. Patients with a history of surgery or chronic disease around the ipsilateral knee were excluded. A total of 35 patients aged from 18 to 50 years who underwent ACLR with autologous hamstring tendon by the same doctor were enrolled and divided into two groups: the anterior knee pain group (the AKP group) and the non-AKP group, according to the postoperative symptoms and visual analogue scale (VAS) score. The patient baseline characteristics, such as age, gender, were recorded. The patients filled out a questionnaire about the International Knee Documentation Committee (IKDC) scale and sectional Feller scale. Anterior knee laxity and flexion contracture were measured. The morphological features and thickness of the patellar tendon and infrapatellar fat pad (IFP) were measured by two-dimensional ultrasound. The IFP blood flow signal were measured by Doppler ultrasound. The shear wave velocity of the patellar tendon and IFP were measured by ultrasonic elastography. After correlation analysis of some variates with statistical differences, the multivariate logistic regression analysis was conducted to find relevant risk factors.

Univariate analysis showed that the proportion of female patients in the AKP group was higher (P=0.018), the reduction of quadriceps muscle strength in the AKP group was higher than that in the non-AKP group (Z=2.40, P<0.05), ultrasonography showed that the proportion of patients with increased IFP blood flow was higher in the AKP group (P=0.018), and the shear wave velocity of IFP was faster in the AKP group(t=7.64, P<0.05). There was no significant difference in other variates (all P>0.05). Multivariate logistic regression analysis showed that female [odds ratio(OR)=12.13, 95% confidence interval(CI) (1.55, 94.99)], the reduction of quadriceps muscle strength [OR=7.94, 95%CI (1.14, 55.43)] and the increase of IFP blood flow[OR=8.90, 95%CI (1.25, 63.56)] were risk factors for anterior knee pain after ACLR (all P<0.05).

The risk of AKP is higher in female than in men after ACLR. Moreover, the reduction of quadriceps muscle strength, the hyperemia and edema of IFP are risk factors for AKP after ACLR.

To explore the influencing factors of osteoporotic fracture in the elderly and establish a predictive model.

The fracture patients over 65 years old treated in the third Hospital of Hebei Medical University from January 1, 2021 to December 31, 2021 were collected retrospectively and randomly divided into modeling group and internal verification group at the proportion of 7:3. In addition, fracture patients over 65 years old treated in the third Hospital of Hebei Medical University from January 1, 2022 to March 31, 2022 were collected as external verification group, and the data were obtained through medical record inquiry. Multivariate logistic regression analysis was used to screen the influencing factors of osteoporotic fracture. A clinical prediction model of osteoporotic fracture was constructed in the modeling population, which was verified as a whole, internally and externally. The differentiation, calibration and clinical effectiveness of the model were evaluated, and the corresponding diagrams were drawn.

A total of 2, 512 patients with fracture met the inclusion exclusion criteria, including 936 males (37.3%) and 1, 576 females (62.7%). They were divided into two groups: development group (n=1, 751) and internal validation group (n=761). A total of 599 patients with fracture were included in the external validation group. According to multivariate logistic regression analysis, female (OR=1.944, 95% CI: 1.569, 2.409)、age≥75 years old (75-84 years old, OR=2.150, 95% CI: 1.718, 2.714; 85-94 years old, OR=4.285, 95% CI: 2.936, 6.198) 、BMI<18.5 kg/m² (OR=1.885, 95% CI: 1.180, 3.087) 、hypertension (OR=1.441, 95% CI: 1.168, 1.779) and hypoproteinemia (OR=2.484, 95% CI: 1.987, 3.113) were independent risk factors for osteoporotic fracture, which were included in the predictive model and evaluated. The AUC value of the model was 0.734 (95% CI: 0.711, 0.757), 0.717 (95% CI: 0.681, 0.734) in the internal verification group and 0.717 (95% CI: 0.656, 0.759) in the external verification group. The calibration maps verified by the development group, internal and external validation group all show that the prediction ability of the model is excellent, and the P value of H-L test are all higher than 0.05. The DCA curve indicated that the clinical validity of the model was the best when the threshold probability was 0.3-0.8.

Women, over 75 years old, BMI<18.5 kg/m², people with hypertension and hypoproteinemia are prone to osteoporotic fracture. The clinical prediction model established in this study can better predict the risk of osteoporotic fracture.

To explore the clinical significance of intelligent preoperative planning based on the hip replacement robot-assisted system in the population of elderly patients undergoing artificial femoral head replacement for femoral neck fractures.

The data of the patients who accepted artificial femoral head replacement for unilateral femoral neck fracture from October 2019 to February 2022 in the Department of Bone and Joint, the Second Affiliated Hospital of Xi′an Jiaotong University were retrospectively analyzed. Pathological fractures, the fracture time longer than four weeks and severe osteoporosis were exluded. All the patients received the surgery with a posterolateral approach by the same group of surgeons using the same biological fixation prosthesis. Age, gender, body mass index (BMI), operation time, intraoperative blood loss, whether conducting preoperative planning or not, the size of preoperative planning and actual use of femoral stem prosthesis were recorded; the intraoperative periprosthesis fracture was determined according to the surgical records and postoperative X-ray. The types of fracture were determined by Vancouver classification. The patients were divided into two groups based on whether or not preoperative planning was performed; the baseline data, duration of surgery, intraoperative blood loss, and incidence of intraoperative periprosthetic fractures were compared between the two groups using independent samples t test and chi square test.

A total of 186 patients were included in this study, including 59 males and 127 females. The age was(84±4) years, average BMI was(23±4)kg/m^2, the operation time was(44±7)min, and the intraoperative blood loss was(265±45)ml. Sixty-two patients adopted preoperative planning before the surgery, and the femoral stem prostheses were successfully implanted according to the planned femoral stem models in 56 patients, while the actual implant models in six patients were inconsistent with the planned femoral stem models. Among the 186 patients, nine had periprosthesis fractures during the operation, one in the preoperative planning group and eight in the non-preoperative planning group. The operative time and the blood loss were less in the planned group than in the unplanned group (t=10.153, 11.412, both P<0.05). The incidence of intraoperative periprosthesis fractures in the planned group was lower than that in the unplanned group (1.6% vs.6.5%), but the difference was not statistically significant(P=0.227).

Preoperative planning based on robot-assisted system can effectively reduce operative time and intraoperative blood loss, and whether it can reduce the incidence of intraoperative periprosthesis fracture needs to be studied in a larger sample.

To evaluate the stress distribution and displacement of femoral and implant models after partial femoral head replacement by finite element analysis.

A healthy adult volunteer was selected to obtain the full-length CT scan data of femur. Mimics 20.0 software, Geomagic software and UG NX 12.0 software were used to establish the model of femoral head ischemic necrosis. The femoral head prosthesis was designed and developed after bone tunnel resection. The finite element simulation was conducted to simulate the one-leg standing environment, and the stress distribution and displacement data of the femur and the implant model were obtained.

The femoral stress distribution mainly concentrated on the lower part of the femoral neck and both sides of the femoral shaft cortical bone, the maximum stress was 48.25 Mpa, the maximum displacement was 10.98mm. The stress of the implant model was mainly distributed under the main structure of the metal implant, with a maximum stress of 147.2 Mpa and a maximum displacement of 9.58mm.

After partial replacement of femoral head, the curvature of prosthetic head and femoral head is the same, and the stress conduction mode is the same as that of normal hip joint. However, stress concentration occurs at the joint between prosthetic head and stem, and the choice of materials with higher strength should be considered.

To compare the anatomical parameters about anterior inferior iliac spine at different ages (18-40, 41-60, ≥ 61).

155 normal subjects (male, 115; female, 40) were enrolled, and the maximum length, width, height, surface area and volume were all measured and compared.

The maximum width (41-60 years, 12.0±1.9 VS 9.5±1.1 mm; ≥ 61 years, 12.0±1.8 VS 9.5±1.6 mm), surface area (41-60 years, 444.11±139.24 VS 328.96±92.64 mm²; ≥ 61 years, 469.03±132.26 VS 326.26±118.32 mm²) and volume of the anterior inferior iliac spine (41-60, 910.19±452.34 VS 577.04±259.51 mm3; ≥ 61 years, 989.09±442.99 VS 482.47±254.34 mm3) in males (41-60, ≥ 61 years old respectively) were significantly higher than those in females at the same age group, and the differences were significant (P<0.001). In the age group ≥ 61 years, the maximum height was also statistically significant in males and females (P=0.007). Anatomical parameters compared in different age groups (18-40, 41-60, ≥ 61 years old) were not statistically significant in men and women. The most commonly observed type of anterior inferior iliac spine was Type 1 in all three male or female ages.

The morphology of the anterior inferior iliac spine is relatively stable and has no significant correlation with age, but the volume and surface area are significantly different in the same age group with different genders. In addition, the low anterior inferior iliac spine (Type 2) does not necessarily lead to acetabular impingement syndrome in normal people.

To investigate the correlation between preoperative ASB and PJI after the initial artificial joint replacement by comparing the incidence of periprosthetic infection (PJI) between patients with preoperative asymptomatic bacteriuria (ASB) and patients without preoperative infection after primary arthroplasty, and to provide a basis for the treatment of preoperative ASB.

From January 2015 to December 2018, 1 294 patients with primary artificial joint replacement were analyzed in the Department of Orthopedics of the Second Affiliated Hospital of Xi′an Jiaotong University, and a total of 132 patients with a definitive diagnosis of ASB (prevalence of 10.2%) and 1 162 patients (89.8%) of non-ASB patients were confirmed. Exclusion criteria: patients with preoperative urinary tract infections, patients with previous urinary tract diseases, or other local infections. The ASB patients were divided into two groups, the treated group and the untreated group. The patients were followed up≥12 months after discharge, with postoperative PJI as the clinical outcome. Clinically characteristic factors (including age, sex, surgical site, presence of diabetes mellitus, obesity) and the presence or absence of ASB were included in the univariate analysis, and bacteriological cultures of periprosthetic secretions were compared with the results of urine cultures in patients with PJI.

The incidence of PJI in the ASB group was 4. 6% (6/132); while the incidence of PJI was 1.3% (15/1 162) in The non-ASB group. The results showed that the incidence of PJI in the ASB group was significantly higher than that in the non-ASB group (χ²=7.864, P=0.005). Univariate analysis showed that the proportion of PJI patients with ASB was higher (P<0.05). There was no significant difference between the patients with or without diabetes or obesity (all P>0.05). In the ASB patients, the incidence of postoperative PJI was 4.7% (3/64) in the treatment group and 4.4% (3/68) in the untreated group; there was no significant difference between the two groups (P=1). The preoperative urine culture of the patients with ASB was mostly Gram-negative bacilli, especially escherichia coli, while the etiology of PJI infection was mostly Gram-positive cocci. Microbes isolated in PJI did not match those in the preoperative urine cultures of all the ASB patients, and no other factor was significantly associated with Gram-negative infection.

The use of antibiotics before artificial joint replacement in ASB patients does not significantly reduce the incidence of postoperative PJI. Moreover, the bacteria cultured in the urine of infected patients may not be consistent with the bacteria cultured locally in the PJI wound, nor does it support a direct relationship between PJI and ASB. Preoperative antibiotic therapy for ASB in patients with ASB is not necessary.

Rotator cuff injury is one of the most common tendon injuries in adults. Rotator cuff injury has a high incidence of 22% in 65 years old and can increase to over 62% in 80 years old. With the rapid development of rotator cuff surgery technology, the expenditure of medical systems in various countries is increasing year by year, and the disease itself can bring great pain to patients with obvious pain at night, affecting daily work and life. Therefore, early and accurate diagnosis of rotator cuff injury is of great significance. Preoperative imaging examination of the nature and size of rotator cuff injury is of great value to the selection of treatment and prognosis. Magnetic resonance imaging (MRI) has become one of the most commonly used examination methods for preoperative diagnosis of rotator cuff injury due to its non-invasive, good tissue illumination and accurate information of muscle atrophy, degree of fat infiltration and labial injury. It has been widely used in clinical diagnosis and treatment. Some studies have shown that arthroscopic measurement of rotator cuff tear has high accuracy and can be used as the gold standard for detection. Previous studies in our department have shown that MRI has good specificity and sensitivity for rotator cuff injury, and is an effective auxiliary examination method. As far as we know, there is no systematic quantitative analysis of the consistency between rotator cuff tears of different degrees in MRI and specific values measured under arthroscopy. The choice of treatment and prognosis of rotator cuff tear vary with the degree of rotator cuff tear. Therefore, it is of great significance to accurately determine the value of rotator cuff tear before surgery for the selection of correct treatment and improvement of healing rate and postoperative function.

To determine the accuracy of the MRI for detection and measurement of the size of rotator cuff tears, including full-thickness tear and partial-thickness tear, with arthroscopic findings used as the standard.

From December 2016 to November 2017, 212 patients were selected from the department of orthopaedics and traumatology in our hospital, MRI examination and intraoperative diagnosis were performed in 205 cases, including 112 cases with full-thickness tear and 93 cases with partial tear. For full-thickness tears, the anteroposterior diameters and medial-lateral diameters of the tears were measured under MRI and arthroscopy, and Bland-Altman test was used for consistency analysis. For partial tears, the depth of the tear was measured under MRI and arthroscopy, and the newe classification was made according to Ellman classification. The consistency of the two classifications were compared by Kappa test.

For the full-thickness tear, the mean difference of the tear length between the two methods was -0.4 mm, and the standard deviation was 2.2 mm. 95% conformance boundaries are (-4.8, 4.0) mm. 96.4% of the points were within the range of LOA. For the tear width group, the mean difference was -0.1 mm, and the standard deviation was 2.3 mm. The calculated 95% consistency limit was (-4.6, 4.4) mm. 95.5% of the points were located within the LOA range. For 93 patients in the partial tear group, 29 patients were classified as Ellman I, 47 patients as Ellman II, and 17 patients as Ellman III. The tearing depth was measured according to Ellman classification, with 30 patients classified as Ellman I, 45 patients as Ellman II, and 18 patients as Ellman III. After Kappa consistency test, the standard deviation was 0.06 and 95% CI was 0.620-0.856. The weighed Kappa value was 0.738.

For full-layer tears, MRI and arthroscopy have a high degree of consistency in the measured values of medial-lateral diameters and anteroposterior diameters. It can accurately predict the degree of tear quantitatively. The measurement of partial tear degree also has good consistency, but does not reach the ideal limit. The results of MRI examination cannot be used as the only standard for the diagnosis and classification of partial tears. In clinical practice, the results of other examinations should be integrated to make an accurate judgment.

To analyze knee kinematic and kinetic parameters after mobile bearing unicompartmental knee arthroplasty (UKA) during postoperative squatting-standing activity, so as to evaluate the efficacy of UKA, guide the process of postoperative rehabilitation and predict complications.

This study was a clinical cohort study. Thirty-one patients were admitted to the Second Affiliated Hospital of Xi’an Jiaotong University from June 2016 to June 2018 diagnosed with medial knee OA with primary UKA were followed up. After case screening, Kellgren & Lawrence stage one or two, lower limb trauma, tumor, excessive body mass index (BMI), and other complications were excluded, then 26 patients were recruited to take gait tests. Squatting-standing activities were performed under the test of Vicon T40 10-Camera Motion Analysis System and Advanced Medical Technology Incorporated (AMTI) force plates preoperatively at different stages after UKA (12, 18, 24 months). Twenty-two healthy subjects were enrolled as the control group, and the difference of squatting pattern between the healthy group and the UKA patients was compared by double-tail t test.

The average duration of follow-up was (24.4±1.5)months. At one year follow-up, the peak values of varus angle (21.20±2.30) °, internal rotation angle (16.90±1.80) °, the torques of knee extension (0.310±0.040) N/kg and internal rotation (0.020±0.008) N/kg of the UKA knees were inferior to contralateral knees. The peak adductor moment (1.220±0.050) N/kg was superior to the contralateral knees.

Mobile UKA can improve the ROM and torques of the involved knee and don’t affect the biomechanical indicators of healthy limbs. OA knees show decreased torque of knee extension and increased torque of knee adduction during active deep flexion activity in early postoperative period. With rehabilitation time elongation, the patients can achieve better range of motion and more natural torques of knee extension and adduction, which may predict ideal functional outcome in medium and long terms.