Objective To evaluate the mechanisms of p42/p44 kinase phosphorylation in cell models and to investigate the effect of simvastatin on the prevention and treatment of aseptic loosening of prosthesis by observing the influence of simvastatin on the levels of tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1) of human peri pheral blood mononuclear cell (PBMC) challenged with titanium particles. Methods PBMC from 45 mL peripheral blood of healthy adult voluntary donators, were separated and cultured, and divided into 5 groups according to different culturemedium: group A, PBMC and titanium particles; group B, PBMC and titanium particles with 1 × 10-5 mol/L simvastatin; group C, PBMC and titanium particles with 1 × 10-6 mol/L simvastatin; group D, PBMC and titanium particles with 1 × 10-7 mol/L simvastatin; and group E, PBMC and titanium particles with the extracellular signal-regulated kinase (ERK1/2) inhibitor U0126. The contents of TNF-α and MCP-1 were tested by ELISA after 24 hours of culture. PBMC were pretreated with different medium grouping as groups A, B, C, D, and E for 60 minutes, and were challenged with titanium particles for 30 minutes and 60 minutes, then the level of ERK1/2 expression was tested by Western blot. Results In groups A, B, C, D, and E, the absorbance (A) values of TNF-α were 1.115 5 ± 0.243 6, 0.693 6 ± 0.354 3, 0.695 7 ± 0.387 3, 0.716 4 ± 0.478 9, and 0.263 5 ± 0.101 6, respectively; and the A values of MCP-1 were 1.421 0 ± 0.105 3, 0.915 1 ± 0.411 3, 1.003 5 ± 0.464 2, 1.102 0 ± 0.353 9, and 0.271 3 ± 0.145 1, respectively. The levels of TNF-α and MCP-1 in group A were significantly higher than others, showing significant differences (P lt; 0.05). There were significant differences between group E and groups B, C, and D (P lt; 0.05), between group B and groups C, D (P lt; 0.05); no significant difference between group C and group D (P gt; 0.05). Western blot results showed the expression of ERK1/2 in all groups at 30 minutes and 60 minutes of culture. The levels of ERK1/2 expression were 1.612 1 ± 0.068 2, 1.078 1 ± 0.072 8, 1.268 7 ± 0.223 1, 1.439 7 ± 0.180 1, and 0.732 0 ± 0.110 4 in groups A, B, C, D, and E, respectively; showing significant differences between groups (P lt; 0.05). Conclusion ERK1/2 is a phosphorylated protein after stimulated by wear particles; it is also one of the most important cell signal ing activation of macrophage. Simvastatin can inhibit the expression of bone absorptive factors induced by wear particles and may be used in the prevention and treatment of aseptic loosening of prosthesis.
Objective To compare the effect of sciatic nerve block (SNB) combined with continuted femoral nerve block (FNB) or continuted adductor canal block (ACB) on pain and motor function after total knee arthroplasty (TKA). Methods A total of 60 patients with TKA-treated osteoarthritis of the knee who met the selection criteria were enrolled between November 2020 and February 2021 and randomised allocated into the study group (SNB combined with continuted ACB) and the control group (SNB combined with continuted FNB), with 30 cases in each group. There was no significant difference in gender, age, body mass, height, body mass index, preoperative Hospital for Special Surgery (HSS) score, femoral tibial angle, and medial proximal tibial angle between the two groups (P>0.05). The operation time, the initial time to the ground, the initial walking distance, and the postoperative hospital stay were recorded. At 2, 4, 6, 12, 24, and 48 hours after operation, the numerical rating scale (NRS) score was used to evaluate the rest pain around the knee joint, the quadriceps femoris muscle strength was evaluated by the freehand muscle strength method, and the knee flexion and extension angles were measured. Results There was no significant difference in the operation time and initial walking distance between the two groups (P>0.05); the initial time to the ground and postoperative hospital stay of the study group were significantly shorter than those of the control group (P<0.05). Except for the 48-hour postoperative NRS score of the study group, which was significantly lower than that of the control group (P<0.05), there was no significant difference in the NRS scores between the two groups at the remaining time points (P>0.05). The quadriceps femoris muscle strength from 4 to 24 hours postoperatively and the knee extension angle from 2 to 6 hours postoperatively of the study group were significantly better than those of the control group (P<0.05); the differences in the quadriceps femoris muscle strength and knee extension and flexion angles between the two groups at the remaining time points were not significant (P>0.05). Conclusion SNB combined with either continuted ACB or continuted FNB can effectively relieve pain in patients after TKA, and compared with combined continuted FNB, combined continuted ACB has less effect on quadriceps femoris muscle strength, and patients have better recovery of knee flexion and extension mobility.
Objective To evaluate the influence of patellar replacement on total knee arthroplasty by comparing with non pattelar replacement. Methods Between September 2010 and November 2010, 63 patients (63 knees) with osteoarthritis who met the selection criteria and underwent total knee arthroplasty, were randomly divided into 2 groups: patellar replacement in 32 cases (replacement group), non patellar replacement in 31 cases (non pattelar replacement group). There was no significant difference in gender, age, disease duration, osteoarthritis grading, the clinical and functional scores of American Knee Society Score (KSS), the patellar tilt angle, tibiofemoral angle, and patellar ligament ratio between 2 groups (P gt; 0.05), they were comparable. After 6 weeks, 3, 6, and 12 months of operation, clinical and imaging evaluation methods were used to assessment the effectiveness. Results Primary healing of incision was obtained in all patients of 2 groups. Deep venous thrombosis occurred in 6 cases of replacement group and in 8 cases of non pattelar replacement group. All patients were followed up 12 months. The postoperative incidence of anterior knee pain in replacement group was significantly lower than that in non pattelar replacement group (P lt; 0.05) at 3, 6, and 12 months after operation. No significant difference was found in the postoperative KSS clinical score between 2 groups at each time point (P gt; 0.05). The joint function score of the replacement group was significantly higher than that of the non pattelar replacement group at the other time point (P lt; 0.05) except the score at 6 weeks and 3 months. Significant difference was found in the patella score between 2 groups at 12 months (P lt; 0.05), but no significant difference at the other time points (P gt; 0.05). X-ray film showed no patellar fracture and dislocation, or loosening and breakage of internal fixation. At 12 months after operation, the tibiofemoral angle, the patellar ligament ratio, and the patellar tilt angle showed no significant difference between 2 groups (P gt; 0.05). Conclusion Patella replacement can improve knee function score and the patella score, and reduce the incidence of postoperative anterior knee pain.
Objective To investigate the impact of difference between the medial and lateral posterior condyle cartilage thickness on osteotomy in total knee arthroplasty (TKA) by measuring the thickness of the medial and lateral femur posterior condylar cartilage and the posterior condylar angle (PCA) in osteoarthritis (OA) patients. Methods Between May and December 2011, 53 OA patients (60 knees) scheduled for TKA met the inclusion criteria (OA group). There were 12 males (14 knees) and 41 females (46 knees), aged 57-82 years (mean, 71.9 years). The tibiofemoral angle was (183.2 ± 2.6) ° . Fifteen healthy volunteers (30 knees) were taken as controls (control group); there were 6 males and 9 females, aged 59-68 years (mean, 66.3 years). MRI scan data were imported into Mimics10.01 medical image control system to measure the thickness of femur posterior condylar cartilage and the PCA with and without femur posterior condylar cartilage. Results In the control group, the thickness of the medial and lateral femur posterior condylar cartilage was (1.85 ± 0.33) mm and (1.92 ± 0.27) mm respectively, the PCA with and without femur posterior condylar cartilage was (5.0 ± 0.9)° and (5.1 ± 0.8)° respectively, all showing no significant differences (P gt; 0.05). In OA group, the thickness of the medial and lateral femur posterior condylar medial cartilage was (0.45 ± 0.40) mm and (1.78 ± 0.51) mm respectively, the PCA with and without femur posterior condylar cartilage was (3.3 ± 1.7)° and (4.8 ± 1.8)° respectively, all showing significant differences (P lt; 0.05). In OA group, the difference between lateral and medial cartilage thickness was (1.33 ± 0.45) mm, and the difference between PCA with and without femur posterior condylar cartilage was (1.5 ± 1.3)°. There was a positive correlation between the difference of cartilage thickness and the difference of PCA (r=0.75, P=0.01). Conclusion There is significant difference between medial and lateral femur posterior condylar cartilage wear, which leads to difference of PCA. The difference will impact knee function and longevity of the prosthesis, so the difference should be considered during osteotomy.