OBJECTIVE: To investigate the effectiveness and safety of simultaneous bilateral total knee athroplasty (SB-TKA) for the treatment of patients aged 65 years and younger with bilateral knee osteoarthritis (KOA) by comparing with patients undergoing unilateral total knee arthroplasty (U-TKA). METHODS: A clinical data of patients, who underwent primary TKA for KOA and met the selection criteria between June 2019 and July 2023, was retrospectively analyzed, including 181 patients in the U-TKA group and 52 patients in the SB-TKA group. The baseline data of age, gender, disease duration, body mass index, and preoperative hemoglobin (Hb), knee range of motion (ROM), Oxford knee score (OKS), and visual analogue scale (VAS) score for pain were compared between the two groups, with no significant difference ( P>0.05). The operation time, postoperative hospital stay, and all complications related to knee arthroplasty were recorded. Hb was measured at 2 days after operation and the difference between pre- and post-operation was calculated. The knee function and pain were evaluated by using ROM, OKS score, and VAS score and compared between the two groups. RESULTS: The operation time and postoperative hospital stay duration were significantly shorter in the U-TKA group than in the SB-TKA group ( P<0.05). The difference of Hb was significantly lower in the U-TKA group ( P<0.05). All patients were followed up 12-61 months (mean, 37.2 months). There was no significant difference in follow-up time between the two groups ( P>0.05). At last follow-up, the ROM, OKS score, and VAS score of both groups were better than the preoperative ones, and the differences were significant ( P<0.05); there were significant differences between the two groups in the ROM and OKS score ( P<0.05), while no significant difference was found in the VAS score ( P>0.05). Mild complications were observed in 31 cases (17.13%) and severe complications in 3 cases (1.66%) in the U-TKA group, while mild complications were observed in 14 cases (26.92%) in the SB-TKA group, and no severe complication occurred. There was no significant difference in the incidences of mild and severe complications between the two groups ( P>0.05). CONCLUSION In patients aged 65 years and younger with bilateral KOA, knee function and mobility can significantly improved when treated by SB-TKA. While patients had lower postoperative knee mobility and function scores compared with U-TKA, there was no significant difference in pain scores or overall incidence of complication. Strict patient selection and scientific perioperative management are important to achieve good effectiveness after operation in patients with SB-TKA.
Humans ; Arthroplasty, Replacement, Knee/adverse effects* ; Male ; Female ; Retrospective Studies ; Osteoarthritis, Knee/physiopathology* ; Range of Motion, Articular ; Treatment Outcome ; Middle Aged ; Operative Time ; Length of Stay ; Knee Joint/physiopathology* ; Pain Measurement ; Postoperative Complications/epidemiology* ; Aged

OBJECTIVE: To review the application progress of customized steel plates in osteotomy and orthopedic treatment for knee osteoarthritis (KOA), and provide reference for orthopedic surgeons and researchers. METHODS: Extensive review of the literature on customized steel plates for osteotomies and knee-preserving surgeries for KOA, 2015-2025, with an overview of the principles of customized steel plate design, clinical applications, and future directions, describing their advantages and shortcomings. RESULTS: Customized steel plates have demonstrated many advantages in osteotomy and orthopedic treatment of KOA, which not only enhance surgical outcomes and optimize mechanical properties, but also reduce the incidence of postoperative complications. However, high cost, long manufacturing period, and selection of patient indications are still important factors restricting their use. CONCLUSION Customized steel plates show promising potential in treating KOA. Not only do they reduce surgical duration and enhance postoperative healing outcomes, but they also effectively lower the incidence of postoperative complications, thereby improving patients' quality of life.
Humans ; Osteoarthritis, Knee/surgery* ; Osteotomy/methods* ; Bone Plates ; Postoperative Complications/epidemiology* ; Steel ; Quality of Life ; Treatment Outcome ; Knee Joint/surgery*

OBJECTIVE: To investigate the characteristics of Vitamin D (VitD) and bone metabolism in patients with knee osteoarthritis (KOA) concurrent with osteoporosis (OP). METHODS: A retrospective analysis was performed on 240 patients who were admitted to the orthopedics department between March 2019 and March 2024. Patients were stratified into four distinct groups according to their respective disease categories.There were 90 patients in the simple KOA group, comprising 13 males and 77 females, age ranged from 50 to 91 years old with an average of (68.48±8.96) years old. There were 90 patients in the simple OP group, comprising 7 males and 83 females, age ranged from 52 to 88 years old with an average of (69.60±8.94 )years old. There were 30 patients in the KOA with OP group, comprising 1 male and 29 females, age ranged from 51 to 91 years old with an average of(69.03±7.93) years old. There were 30 patients in the physical examination group, comprising 5 males and 25 females, age ranged from 53 to 79 years old with an average of(64.93±6.51) years old. The general data and the levels of osteocalcin (OC), β-CrossLaps, parathyroid hormone(PTH) and VitD in each group were observed. RESULTS: The level of VitD in KOA with OP group (19.62±10.38) ng·ml^-1 and OP group (20.65±10.50) ng·ml^-1 was lower than that in physical examination group (27.46±8.00) ng·ml^-1 and KOA group (24.01±9.11) ng·ml^-1 (P<0.05). There were significant differences in β- CrossLaps and PTH levels among the four groups (P<0.001, P=0.019, respectively), while there was no significant difference in OC levels (P=0.763). Compared with the two simple disease groups, the KOA with OP group had higher levels of β - CrossLaps(0.81±0.30) ng·ml^-1 (P<0.001). There were significant differences in β-CrossLaps and PTH between the simple KOA group(0.54±0.22) ng·ml^-1, (46.03±18.08) pg·ml^-1 and the physical examination group (0.44±0.19) ng·ml^-1, (36.65±9.63) pg·mL^-1(P=0.038;P=0.006). There was a significant difference in PTH between the OP group(43.85±14.30) ng·ml-1, and the physical examination group, P=0.004. There was a significant difference in Kallgren-Lawrence grading between KOA with OP group and KOA group (P=0.006). Within KOA with OP group, the differences of β-CrossLaps and VitD levels among different K-L grades were statistically significant (P=0.016). The level of OC, β-CrossLaps and PTH within KOA with OP group was significantly different at different VitD levels (P=0.013, P=0.033, P=0.046). CONCLUSION Patients with KOA complicated by OP exhibit greater disturbances in bone metabolism and reduced VitD levels, particularly reflected by elevated β-CrossLaps. These findings underscore the importance of early monitoring of bone turnover and VitD supplementation in advanced-stage KOA with bone loss.
Humans ; Female ; Male ; Middle Aged ; Aged ; Vitamin D/blood* ; Osteoporosis/complications* ; Aged, 80 and over ; Osteoarthritis, Knee/complications* ; Retrospective Studies ; Bone and Bones/metabolism* ; Parathyroid Hormone/metabolism* ; Osteocalcin/metabolism*

OBJECTIVE: To investigate the risk factors associated with the development of knee osteoarthritis (OA) following arthroscopic surgery for degenerative lesions of the posterior horn of the medial meniscus. METHODS: Between January 2012 and January 2014, a retrospective analysis was conducted on 506 patients who underwent arthroscopic surgery for degenerative disease of the posterior horn of the medial meniscus. The cohort included 230 males and 276 females, aged from 32 to 58 years old with an average of (46.77±9.02) years old. According to the results of postoperative follow-up, patients were categorized into a knee osteoarthritis(OA) group and a non-OA group. The following parameters were recorded for each subject:gender, medial proximal tibial angle (MPTA), hip-knee-ankle angle (HKA), presence of bone edema on MRI, physical characteristics (including McMurray test results, locking symptoms, and medial knee tenderness points), meniscus protrusion, type of meniscus injury, and free body condition as observed via arthroscopy. Multivariate unconditional Logistic regression analysis was employed to investigate the associated factors influencing the 10-year postoperative incidence of knee osteoarthritis following surgery for degenerative injury of the posterior horn of the medial meniscus. Independent risk factors potentially influencing the development of postoperative OA were identified, and a nomogram-based predictive model for postoperative OA was established. The discriminatory ability and calibration accuracy of the model were assessed using the C-index and Hosmer-Lemeshow goodness-of-fit test, respectively. Furthermore, internal validation was performed using the bootstrap resampling method. RESULTS: Within a 10-year period following arthroscopic surgery, there were 123 patients in the OA group and 383 patients in the non-OA group. Significant differences were observed between two groups with respect to gender (χ²=5.156, P=0.023), MPTA<86.6° (χ²=21.671, P<0.001), varus lower limb alignment( χ²= 80.086, P<0.001). Additionally, meniscus extrusion (χ²=6.371, P=0.012), meniscus transverse tear (χ²=14.573, P<0.001), and bone edema detected on MRI(χ²=9.881, P=0.002) were identified as factors associated with the development of postoperative knee OA. The multifactorial Logistic regression analysis revealed that the lower limb line of force inversion OR=4.324, 95%CI (1.391, 13.443), P=0.011;MPTA <86.6°, OR=2.519, 95%CI (1.150, 5.519), P=0.021;transverse meniscus tear, OR=4.546, 95%CI (1.827, 11.310), P=0.001;meniscus ectropion, OR=5.401, 95%CI (1.992, 14.646), P=0.001;and bone edema manifestation on MRI OR=2.692, 95%CI (1.169, 6.200), P=0.020. They were independent risk factors associated with the development of postoperative OA. The area under the ROC curve predicted by the model was 0.927, 95%CI (0.903, 0.950). The Hosmer-Lemeshow goodness-of-fit test, used to evaluate the accuracy of the model, yielded P=0.689. Additionally, the internally sampled calibration curve demonstrated good consistency with the actual postoperative OA outcomes. CONCLUSION Varus alignment of the lower extremity, MPTA <86.6°, transverse meniscus tear, lateral meniscus injury, and bone marrow edema observed on MRI were independent risk factors for the development of knee osteoarthritis following arthroscopic surgery. Additionally, the prognostic model demonstrated excellent predictive performance.
Humans ; Male ; Female ; Middle Aged ; Arthroscopy/adverse effects* ; Adult ; Retrospective Studies ; Tibial Meniscus Injuries/surgery* ; Osteoarthritis, Knee/epidemiology* ; Risk Factors ; Menisci, Tibial/surgery* ; Incidence ; Postoperative Complications/epidemiology*

OBJECTIVE: To reveal the molecular basis of knee osteoarthritis (KOA) with Yang deficiency and blood stasis syndrome by analyzing the gene expression profiles in synovial fluid and blood of KOA patients with this syndrome. METHODS: A total of 80 KOA patients were recruited from October 2022 to June 2024, including 40 cases in the non-Yang deficiency and blood stasis group (27 males and 13 females), with an average age of (61.75±3.45) years old;and 40 cases in the Yang deficiency and blood stasis group (22 males and 18 females), with an average age of (62.00±2.76) years old. The levels of body mass index (BMI), high-density lipoprotein (HDL), low-density lipoprotein (LDL), fibrinogen, total cholesterol, and D-dimer were recorded and summarized. Blood and synovial fluid samples from patients were collected for gene expression profile microarray sequencing, and then PCR and immunohistochemistry were used for clinical verification on the patients' synovial fluid and cartilage samples. RESULTS: Logistic regression analysis showed that compared with KOA patients with non-Yang deficiency and blood stasis syndrome, those with Yang deficiency and blood stasis syndrome had increased BMI, LDL, fibrinogen, total cholesterol, and D-dimer, and decreased HDL, with a clear correlation between the two groups. There were 562 differential genes in the blood, among which 322 were up-regulated and 240 were down-regulated;755 differential genes were found in the synovial fluid, with 350 up-regulated and 405 down-regulated. KEGG signaling pathway analysis of synovial fluid revealed changes in lipid metabolism-related pathways, including cholesterol metabolism, fatty acid metabolism, and PPARG signaling pathway. Analysis of the involved differential genes identified 6 genes in synovial fluid that were closely related to lipid metabolism, namely LRP1, LPL, ACOT6, TM6SF2, DGKK, and PPARG. Subsequently, PCR and immunohistochemical verification were performed using synovial fluid and cartilage samples, and the results were consistent with those of microarray sequencing. CONCLUSION This study explores the clinical and genomic correlation between traditional Chinese medicine syndromes and knee osteoarthritis from the perspective of lipid metabolism, and proves that abnormal lipid metabolism is closely related to KOA with Yang deficiency and blood stasis syndrome from both clinical and basic aspects.
Humans ; Male ; Female ; Middle Aged ; Synovial Fluid/metabolism* ; Osteoarthritis, Knee/metabolism* ; Yang Deficiency/complications* ; Aged

OBJECTIVE: To compare the mid- and long-term effectiveness of patellar resurfacing versus non-resurfacing in primary total knee arthroplasty (TKA). METHODS: Twenty-six patients who underwent bilateral TKA between March 2013 and September 2015 were selected as the study subjects. One side was randomly chosen for patellar resurfacing (resurfacing group), and the other side was not (control group). There were 4 males and 22 females, the age ranged from 51 to 65 years, with an average of 59 years. According to Kellgren-Lawrence classification, there were 21 cases of grade Ⅳ and 5 cases of grade Ⅲ in both knees. There was no significant difference in the surgical side, and preoperative clinical and functional scores of the Knee Society Score (KSS), visual analogue scale (VAS) score, and the composition ratio of anterior knee pain localization points between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative abnormal signs such as patellar clunk, feeling of constraint, patellar tendon weakness, crepitus, or snow-on-glass sensation, and the occurrence of complications were recorded and compared. Patient subjective evaluations included Forgotten Joint Score (FJS) and the degree of difficulty in high-level knee activities (including flexion with load bearing, going upstairs, going downstairs, squatting and standing up, kneeling, knee extension, and crossing legs for 7 items); KSS clinical/functional scores and VAS scores were used to evaluate the recovery of knee joint function, and the location of anterior knee pain was determined by a localization diagram. RESULTS: The operation time of the resurfacing group was significantly longer than that of the control group ( P<0.05), and there was no significant difference in intraoperative blood loss between the two groups ( P>0.05). All patients' incisions healed by first intention; the hospital stay ranged from 8 to 23 days, with an average of 12.6 days. All patients were followed up 9-11 years, with an average of 9.7 years. Except for 1 case who died of multiple organ failure due to internal diseases at 9 years after operation and 5 cases with incomplete radiological data, the rest 20 patients were assessed radiologically and found that 1 side of the knee joint in the control group had patellar dislocation; the remaining patients had no prosthetic failure (fracture, loosening, displacement, etc.), patellar fracture, patellar necrosis, patellar instability, patellar tendon rupture, prosthetic revision, etc. No patients had reoperations due to patellar-related complications or anterior knee pain in both knee joints. At 2 years postoperatively and at last follow-up, there was no significant difference in the incidence of abnormal signs such as patellar clunk, feeling of constraint, patellar tendon weakness, crepitus, or snow-on-glass sensation, the incidence of high-level knee activity difficulty, and the composition ratio of anterior knee pain localization between the two groups ( P>0.05). The KSS clinical scores, functional scores, and VAS scores of both groups significantly improved compared to preoperative ones ( P<0.05); there was no significant difference in the comparison between the two groups at the two time points postoperatively ( P>0.05). At 2 years postoperatively and at last follow-up, there was no significant difference in FJS scores between the two groups ( P>0.05). CONCLUSION Patellar resurfacing or not has similar mid- and long-term effectiveness in primary TKA.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Male ; Middle Aged ; Female ; Patella/surgery* ; Aged ; Treatment Outcome ; Range of Motion, Articular ; Knee Joint/surgery* ; Knee Prosthesis ; Pain Measurement ; Osteoarthritis, Knee/surgery* ; Pain, Postoperative/etiology* ; Follow-Up Studies ; Postoperative Complications ; Recovery of Function

OBJECTIVE: To investigate the effect of body mass index (BMI) on the short-term effectiveness of high tibial osteotomy (HTO) in the treatment of varus knee arthritis. METHODS: The clinical data of 84 patients (84 knees) with varus knee arthritis treated with HTO between May 2016 and August 2020 were retrospectively analyzed. According to BMI, the patients were divided into normal group (32 patients in group A, BMI<25 kg/m ²), overweight group (27 patients in group B, BMI>30 kg/m ²), and obese group (25 patients in group C, BMI>30 kg/m ²). The BMI of groups A, B, and C were (23.35±0.89), (26.65±1.03), and (32.05±1.47) kg/m ², respectively. There was no significant difference ( P>0.05) in gender, age, surgical side, disease duration, and preoperative Hospital for Special Surgery (HSS) score, visual analogue scale (VAS) score, knee range of motion, and hip-knee-ankle angle (HKA) between groups. The operation time, intraoperative dominant blood loss, and the decrease of hemoglobin on the 3rd day after operation were recorded and compared between groups. The improvement of knee joint function and pain status were evaluated by knee joint HSS score, knee range of motion, and VAS score before and after operation, and measuring the HKA of patients on X-ray film. During the follow-up, the X-ray films of the knee joint were reexamined to observe the position of the internal fixator and the healing of osteotomy. RESULTS: All patients completed the operation successfully and were followed up 8-40 months (mean, 19.3 months). There was no significant difference in follow-up time, operation time, intraoperative dominant blood loss, and the decrease of hemoglobin on the 3rd day after operation between groups ( P>0.05). No operative complications such as severe vascular or nerve injury occurred. After operation, deep venous thrombosis of lower extremities occurred in 1 case in groups A and B respectively, and fat liquefaction of surgical incision occurred in 2 cases in group C. There was no significant difference in the incidence of perioperative complications between groups (3.1% vs. 3.7% vs. 8.0%) ( P=0.689). During the follow-up, there was no bone nonunion, plate fracture or loosening. At last follow-up, HSS score, VAS score, knee range of motion, and HKA significantly improved in the 3 groups when compared with those before operation ( P<0.05), but there was no significant difference in the differences of the above indexes between groups before and after operation ( P>0.05). CONCLUSION BMI does not affect the short-term effectiveness of HTO in the treatment of varus knee arthritis. HTO can be selected for overweight and obese patients after standard medical treatment is ineffective.
Humans ; Osteoarthritis, Knee/surgery* ; Body Mass Index ; Overweight ; Retrospective Studies ; Treatment Outcome ; Knee Joint/surgery* ; Obesity/complications* ; Osteotomy ; Blood Loss, Surgical

OBJECTIVE: To explore relationship between bone marrow edema(BME) and osteoporosis in patients with severe knee osteoarthritis. METHODS: Unmatched case-control study was conducted. Totally 160 patients with severe knee osteoarthritis who had undergone knee magnetic resonance imaging (MRI) and bone mineral density examination (BMD) from January 2020 to March 2021 were included. Eighty patients complicated with BME were included in BME group, and 80 patients without BME were selected as NBME group. In BME group, there were 12 males and 68 females, aged from 51 to 80 years old with an average of(66.58±8.10) years old;the courses of disease ranged from 5 to 40 months with an average of (15.61±9.25) months;body mass index(BMI) ranged from 21.81 to 34.70 with an average of (27.79±3.00) kg·m^-2;25 patients classified to grade Ⅲ and 55 patients grade Ⅳ according to Kellgren- Lawrence(K-L). In NBME group, there were 15 males and 65 females, aged from 50 to 80 years old with an average of(67.82±8.05) years old;the course of disease ranged from 6 to 37 months with an average of(15.75±8.18) months;BMI ranged from 21.39 to 34.46 with an average of (28.26±3.13) kg·m^-2;25 patients were K-L Ⅲ and 55 patients with K-L Ⅳ. The degree of bone marrow edema was evaluated by knee whole oragan magnetic resonance imaging score(WORMS). Osteoporosis was diagnosed and BMD was evaluated by DXA T value. To explore the relationship between bone marrow edema and osteoporosis by comparing prevalence rate of osteoporosis between two groups, and to further explore relationship between BME and BMD by Spearman correlation analysis of BME WORMS score and DXA T value in BME group. RESULTS: The complete case data were obtained on the first diagnosis, and there was no significant difference in sex, age, courses of disease and BMI between two groups (P>0.05). The proportion of K-L Ⅳ in BME group was significantly higher than that in NBME (P<0.05). The prevalence rate of osteoporosis in BME group was significantly higher than in NBME group with the same K-L grade (P<0.001), and there was a strong negative correlation between BME WORMS score and DXA BMD T value (r=-0.812, |r|=0.812 >0.8, P<0.001). CONCLUSION Osteoporosis is one of the risk factors of bone marrow edema in patients with severe knee osteoarthritis, and the lower the bone mineral density is, the easier it is to be complicated with bone marrow edema.
Male ; Female ; Humans ; Osteoarthritis, Knee/diagnostic imaging* ; Bone Marrow/pathology* ; Case-Control Studies ; Bone Marrow Diseases/etiology* ; Osteoporosis/complications* ; Edema/etiology* ; Magnetic Resonance Imaging/methods*

Objective: To investigate the changes of imaging parameters of patellofemoral joint after kinematic alignment total knee arthroplasty (KA-TKA) and mechanical alignment total knee arthroplasty (MA-TKA) and the effects on clinical outcomes. Methods: A retrospective analysis was performed on 227 patients diagnosed with knee osteoarthritis, 105 males and 122 females, with the age of (68.6±7.2) years (range: 52 to 86 years). The patients underwent unilateral TKA at the Department of Orthopaedic Surgery, Beijing Chaoyang Hospital, Capital Medical University, from January 2020 to July 2021. The patients were divided into the KA-TKA group (n=102) and the MA-TKA group (n=125) according to the alignment method. The Blackburne-Peel index, lateral patellofemoral angle, patellofemoral tilt angle and patellofemoral index of the two groups were recorded before and 6 months after operation. The frequency of lateral patellar retinaculum release, preoperative and postoperative knee range of motion (ROM), and Oxford knee score(OKS) were also recorded. The differences between preoperative and postoperative measurement data of each group were calculated. If the difference was in line with normal distribution, the independent sample t-test or t'-test was used for comparison between the two groups. If it did not conform to normal distribution, Mann-Whitney U test was used. Paired sample t-test was used for comparison before and after treatment. Chi-square test was used for comparation of categorical data between the two groups. Results: After 6 months of operation, the patellar tilt angles of the KA-TKA group and the MA-TKA group were (14.22±3.26)° and (13.35±2.27)°, and the lateral patellar angles were (9.73±4.86)° and (11.91±3.89)°, respectively. The change of lateral patellofemoral angle in the KA-TKA group was significantly less than that in the MA-TKA group ((1.68±4.86)° vs. (4.15±4.88)°, t=3.805, P<0.01). OKS and ROM were improved in the both groups at 6 months after operation (all P<0.05), but there were no statistic significance in preoperative and postoperative difference between the two groups (all P>0.05). The intraoperative lateral patellar retinacular release rate was 14.4% (18/125) in the MA-TKA group and 6.9% (7/102) in the KA-TKA group, with no statistical difference (χ²=3.256,P=0.071). Conclusions: There are greater patella lateral tilt at 6 months postoperatively in the KA-TKA group compared with the MA-TKA group, but this radiographic difference could not show differences of clinical outcomes and postoperative ROM, the frequency of intraoperative lateral patellar retinacular release wouldn't increase. Therefore, KA-TKA does not increase the difficulty of postoperative patellofemoral joint complications and intraoperative lateral patellar release.
Male ; Female ; Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/methods* ; Patellofemoral Joint/surgery* ; Biomechanical Phenomena ; Retrospective Studies ; Patella/surgery* ; Osteoarthritis, Knee/surgery* ; Knee Joint/surgery* ; Knee Prosthesis ; Range of Motion, Articular ; Postoperative Complications

OBJECTIVE: To investigate the changes in the expression of voltage-gated potassium channel subunit KCNA2 in the dorsal root ganglion (DRG) neurons of rats with osteoarthritis (OA) pain induced by sodium monoiodoacetate and explore the mechanism. METHODS: A total of 156 adult male Sprague-Dawley rats were randomly divided into blank control group, saline group and intra-articular monoiodoacetate injection-induced OA group. The paw withdrawal mechanical threshold (PWMT) was measured before and at 1, 2, 4, and 6 weeks after monoiodoacetate injection. At 4 weeks after the injection, the pathological changes in the knee joints were analyzed using HE staining and Safranin O-Fast Green staining, and the expression of activating transcription factor 3 (ATF-3) and inducible nitric oxide synthase (iNOS) in the DRG neurons were detected by immunofluorescence staining. The expression of mRNA in the DRG neurons was detected by RT-qPCR at 1, 2, 4 and 6 weeks after the injection. The expression of KCNA2 in the DRG was measured by Western blotting, and the methylation level of promoter region was measured by MSPCR at 4 weeks after the injection. RESULTS: The PWMT of the rats in OA group was significantly decreased at 2, 4, and 6 weeks after the injection as compared with the baseline ( < 0.05 or < 0.001) as well as the control group ( < 0.05 or < 0.001). Four weeks after the intra-articular injection, fractures and defects on the surface of the articular cartilage, bone hyperplasia, and blurred tidal line were observed in the rats in OA group, but no obvious pathological changes were detected in the control or saline groups. Compared with those in the control group, the expressions of ATF-3 and iNOS were significantly increased ( < 0.01) at 4 weeks after injection; the expression of mRNA at 2, 4 and 6 weeks and the expression of KCNA2 protein at 4 weeks were all significantly decreased ( < 0.05 or < 0.01), and the methylation level of gene was significantly increased at 4 weeks after the injection in OA group ( < 0.01). CONCLUSIONS The expression of KCNA2 is decreased in the DRG neurons of rats with OA pain likely as a result of enhanced methylation of promoter region.
Animals ; Disease Models, Animal ; Ganglia, Spinal ; Knee Joint ; Kv1.2 Potassium Channel ; metabolism ; Male ; Osteoarthritis ; complications ; metabolism ; Pain ; etiology ; metabolism ; Promoter Regions, Genetic ; Rats ; Rats, Sprague-Dawley