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.

OBJECTIVETo verify the linkage of the candidate regions identified in a previous study (markers D2S168, D2S151, D2S142 on chromosome 2) with hypertension in Chinese families.

METHODSA genetic linkage study focused on chromosome 2 was performed on 240 Chinese families containing 856 patients with essential hypertension. A total of 1080 individuals were genotyped using 9 highly polymorphic microsatellite markers around the candidate regions on chromosome 2 with an average spacing of 5 cM. Non-parametric linkage (NPL), parametric linkage analysis and transmission-disequilibrium test (TDT) with the GENEHUNTER software were used to assess evidence for linkage.

RESULTSLinkage of a region on chromosome 2 around D2S151 and D2S142 with hypertension was confirmed by different statistical methods (NPL, LOD score and TDT). However, the linkage of D2S168 could not be replicated in this extension study.

CONCLUSIONSThe data suggest that a region on chromosome 2 at or near the loci of D2S142 and D2S151 may harbor genes responsible for the development of essential hypertension in Chinese.

Alleles ; China ; Chromosomes, Human, Pair 2 ; genetics ; Family Health ; Female ; Gene Frequency ; Genetic Linkage ; Humans ; Hypertension ; genetics ; Linkage Disequilibrium ; Male ; Microsatellite Repeats

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.

BackgroundStudents in secondary vocational health school are at the age of puberty and prone to depressive symptoms. Peer victimization and social media addiction are found to be crucial in influencing the development of depression， and positive mental health has been proven to alleviate depressive symptoms， whereas there remains a striking lack of research on the mediating role of positive mental health and social media addiction in the relationship between peer victimization and depressive symptoms among secondary vocational health school students. ObjectiveTo explore the relationship between peer victimization and depressive symptoms and investigate the mediating role of positive mental health and social media addiction， so as to provide references for the prevention of depression among secondary vocational health school students. MethodsFrom October to December 2020， a cluster sampling framework was utilized to recruit 7 307 students from a secondary vocational health school in Luzhou City， Sichuan Province. Assessments were performed using Multidimensional Peer Victimization Scale （MPVS）， Warwick-Edinburgh Mental Well-being Scale （WEMWBS）， Bergen Social Media Addiction Scale （BSMAS） and Patient Health Questionnaire Depression Scale-9 item （PHQ-9）. Spearman correlation analysis was calculated to determine correlations between scores of scales， Process 4.0 was employed to test the mediation effect， and the bias-corrected Bootstrap procedure was used to test the significance of the mediation effect. ResultsA total of 7 044 （96.40%） valid questionnaires were collected. And 4 391（62.34%）students were found to have depressive symptoms. Correlation analysis revealed that PHQ-9 score was positively correlated with BSMAS score and MPVS score （r=0.404， 0.506， P<0.01）. WEMWBS score was negatively correlated with PHQ-9 score， BSMAS score and MPVS score （r=-0.587， -0.259， -0.358， P<0.01）. BSMAS score was positively correlated with MPVS score （r=0.328， P<0.01）. Positive mental health played a mediating role in the relationship between peer victimization and depressive symptoms， with an indirect effect value of 0.130 （95% CI： 0.119~0.141）， accounting for 30.81% of the total effect. Social media addiction also mediated the relationship between peer victimization and depressive symptoms， with an indirect effect value of 0.052 （95% CI： 0.045~0.059）， accounting for 12.34% of the total effect. Positive mental health and social media addiction exhibited a chained mediation effect on the relationship between peer victimization and depressive symptoms， with an indirect effect value of 0.012 （95% CI： 0.010~0.014） and accounting for 2.84% of the total effect. ConclusionPeer victimization can affect the presence of depressive symptoms among secondary vocational health school students both directly and indirectly through either separate or chained mediation of positive mental health and social media addiction.