ABSTRACT
Objective:To compare the effects of patellar position on the balance of soft tissue during the operation and the postoperative outcomes in minimally invasive total knee arthroplasty via a midvastus approach.Methods:From December 2018 to February 2019, a total of 55 patients were enrolled for primary total knee arthroplasty via a midvastus approach. All patients were randomly divided into 2 groups by random number table. During the operation, the gap balance technique was used with patella reduced or subluxated to complete the osteotomy and balance of soft tissue. The changes of gap and varus-valgus angle were compared between the patellar reduction group and the patellar subluxation group in both extension and flexion position. These data were also compared before and after reducing patellar in the patellar subluxation group. Furthermore, the differences of femoral prosthesis rotation, mechanical femoral axis to tibial axis angle, Knee Society score (KSS), visual analogue scale (VAS) and range of motion (ROM) were compared between the two groups.Results:All patients finished 6 months follow-up, including 27 patients in the patellar reduction group and 28 patients in the patellar subluxation group. After osteotomy and soft tissue balance during the operation, there was no significant difference in gap and varus-valgus angle between two groups in either extension or flexion position. While in the patellar subluxation group, the flexion gap was 10.5±0.3 mm with patella subluxated, less than 11.0 ± 0.3 mm after reducing the patella. The varus-valgus angle was 1.5±0.3 with patella subluxated, less than 2.3±0.4 degree after reducing the patella. The difference was statistically significant ( t=4.180, P<0.001; t=7.642, P<0.001). There was no significant difference in extension gap and varus-valgus angle before and after patella reduction in the patellar subluxation group ( P>0.05). The rotation angle of the femoral component in the patellar subluxation group was -0.49°±1.2°, and the external rotation angle was smaller than that in the patellar reduction group (0.24°±1.3°). The difference was statistically significant ( t=2.116, P=0.039). At one month after operation, ROM of the patellar reduction group was 109.6°±8.5° which was higher than that of the patellar subluxation group (104.9°±8.6°, t=2.048, P=0.046). There was no significant difference in ROM between the two groups at 3 and 6 months ( P>0.05). Moreover, there was no significant difference in KSS and VAS at 1, 3 and 6 months after operation ( P>0.05). Conclusion:In the minimally invasive total knee arthroplasty, it is suggested to balance the soft tissue as much as possible with the patellar reduced. Otherwise, the consequence of increased flexion space, increased varus and increased internal rotation of femoral prosthesis should be considered. The patients undergoing soft tissue balance with patella reduced have better ROM in the early stage postoperatively.
ABSTRACT
OBJECTIVE： To optimize the processing technology of fried Radix Paeoniae， and to provide reference for quality control of the processed products. METHODS： The content of paeoniflorin in fried Radix Paeoniae was determined by HPLC. The determination was performed on Agilent ZORBAX SB-C18 column with mobile phase consisted of acetonitrile-0.05 mol/L potassium dihydrogen phosphate solution （15 ∶ 85， V/V） at the flow rate of 1.0 mL/min. The column temperature was 30 ℃， and detection wavelength was set at 230 nm. The sample size was 10 μL. The appearance character of fried Radix Peaoniae were investigated by appearance color， crosssection color， hardness and smell. Taking the comprehensive score of appearance character and paeoniflorin content as evaluation index， the dosage， stir-frying temperature and stir-frying time were investigated. According to the results of single factor test， Box-Behnken response surface methodology was used to optimize above 3 factors. The optimized processing technology was validated. RESULTS： The linear range of paeoniflorin were 0.02-4.15 mg/mL （r＝0.999 9）； precision， stablity， repeatability and sample recovery rate meet the requirements. The optimal technology of fried Radix Paeoniae included the dosage of 374.60 g， frying temperature of 101.61 ℃， frying time of 20 min. Under optimal technology， comprehensive score of fried Radix Paeoniae ranged 97.39-98.82 in 6 times of parallel verification tests （RSD＝0.54％）， which was close to predicted value 98.18. The color of fried Radix Paeoniae was slightly deeper than Radix Paeoniae， which was crisp and fragrant. CONCLUSIONS： The optimized processing technology of fried Radix Paeoniae is stable and feasible， and is suitable for the preparation of the processed products.