BACKGROUND:Rat models of diabetes mellitus type 2 (T2DM) are usually induced by the combination of high-fat diet and low-dose streptozotocin, but their effects on the intervertebral disc have not yet been reported. Endplate sclerosis is an important factor contributing to intervertebral disc degeneration. OBJECTIVE:To evaluate whether the rat T2DM model induced by high-fat diet combined with low-dose streptozotocin is suitable for the study of T2DM related intervertebral disc degeneration. METHODS:Thirty-two 3-month-old female Sprague-Dawley rats were divided into four groups (n=8 per group), including sham, bilateral variectomy, DM, and bilateral variectomy plus DM groups, followed by subjected to bilateral ovariectomy and/or high-fat diet combined with low-dose streptozotocin, respectively. The blood glucose level, body mass and glucose tolerance were determined. The bone mineral density of the lumbar spine was measured after 8-week streptozotocin treatment. The L5-6 segments were removed and cut through midst sagittal plane after decalcification, and then underwent Von Gieson staining and histological degeneration scoring, and the disc height and endplate thickness were measured. RESULTS AND CONCLUSION:Fasting blood glucose and random blood glucose levels in the DM and bilateral variectomy plus DM groups were significantly higher than those in the other two groups, and the insulin sensitivity in the DM and bilateral variectomy plus DM groups were significantly lower than that in the other groups (P<0.05). L4-6 vertebral bone mineral density in the bilateral variectomy group was significantly lower than that in the sham group (P<0.05);L5-6 vertebral bone mineral density in the DM and bilateral variectomy plus DM groups was significantly lower than that in the sham group (P<0.05). L5-6 vertebral histological scores in the DM and bilateral variectomy plus DM groups were significantly higher than those in the other groups (P<0.05). Similar with the bilateral variectomy group, there were chondrometaplasia and mucoid degeneration of nucleus pulposus cells in the bilateral variectomy plus DM group, and the histological scores were significantly higher than those in the sham and DM groups (P<0.05). Compared with the sham group, the intervertebral disc height in the bilateral variectomy and bilateral variectomy plus DM groups was significantly decreased (P<0.05). While, there was no significant difference in the endplate thickness among groups. These results indicate the combination of high-fat diet and low-dose streptozotocin-induced rat T2DM models possess diabetic characteristics, but the rat intervertebral disc tissues show no significant differences from the normal ones;therefore, this model may be unsuitable for the study on T2DM-related intervertebral disc degeneration.

Objective:To investigate the early clinical effectiveness of using customized 3D printed acetabular augment to repair large acetabular bone defects in delayed total hip arthroplasty after failed treatment of acetabular fractures.Methods:A retrospective study was conducted to analyze the 6 patients who had undergone 3D printed acetabular augment to reconstruct acetabular bone defects in delayed total hip replacement from July 2021 to January 2023 after failed treatment of acetabular fractures. They were all males, with an age of (51.3±15.0) years. Paprosky classification: 2 cases of type ⅡB, 1 case of type ⅡC, and 3 cases of type ⅢA. Recorded were surgical time, intraoperative bleeding, hospitalization time, and visual analogue scale (VAS), and modified Merle d'Aubigné & Postel score, Harris hip score, and leg length discrepancy at the last follow-up.Results:For the 6 patients, the mean surgical time was (222.5±46.9) min, the mean intraoperative bleeding 1,100 (1,000, 2,625) mL, the mean hospitalization time (9.0±4.5) d, and the mean follow-up time (11.8±7.9) months. At the last follow-up, the VAS [(2.5±1.0) points] significantly decreased compared with the preoperative value [(6.2±0.8) points], the modified Merle d'Aubigné & Postel score [(13.2±2.1) points] and Harris hip score [(67.8±15.3) points] significantly increased compared with the preoperative values [(6.7±0.8) and (34.2±8.4) points], the vertical position of center of rotation [(22.5±5.2) mm] and the horizontal position of center of rotation [(40.7±2.6) mm] were significantly reduced compared with the preoperative values [(38.1±14.2) and (53.1±10.0) mm] ( P<0.05). At the last follow-up, the leg length discrepancy was (6.2±3.6) mm, showing no statistically significant difference from the preoperative value [(18.7±1.7) mm] ( P>0.05). At the last follow-up, no clear line at the cup-bone or augment-bone interface, or no possible prosthetic loosening or displacement was observed on the X-ray films. Conclusion:In delayed total hip arthroplasty after failed treatment of acetabular fractures, the customized 3D printed augment for repair of large bone defects in the acetabulum can reconstruct the normal rotation center of the hip joint, provide reliable stability for the cup prosthesis, and enable patients to obtain significant improvements in hip function.

Objective:To explore the short-term efficacy of fixation with a 3D printed individualized custom-made plate in the treatment of elderly patients with periprosthetic femoral fracture.Methods:Retrospectively analyzed were the 5 elderly patients with periprosthetic femoral fracture who had been treated by fixation with a 3D printed individualized custom-made plate from January 2022 to July 2022 at Department of Orthopaedics and Traumatology, Beijing Jishuitan Hospital. There were 3 males and 2 females, aged 81, 86, 77, 91 and 87 years, respectively. One left and 4 right limbs were affected. Vancouver classification: type B1 ( n=3), type B2 ( n=1), and type C ( n=1). The time from operation to injury was 5, 6, 10, 5 and 7 days, respectively. Preoperatively, the femur affected, prosthesis and individualized plate with a greater trochanteric hook, loop cable channel and bone-like trabecular microporous structure were custom-made by 3D printing according to 1:1 models. Virtual operations were simulated to formulate surgical protocols. The operation time, length of surgical incision, intraoperative blood loss and transfusion, hospital stay, hip function and complications at the last follow-up were recorded. Results:The 5 patients were followed up for 12, 7, 10, 3 and 6 months, respectively. There were no events of superficial incision or deep prosthesis infection. Respectively, the operation time was 1.8, 1.7, 2.3, 2.0 and 3.3 h; the length of surgical incision 31, 30, 38, 27 and 30 cm; the intraoperative bleeding volume 400, 300, 300, 500 and 600 mL; the length of hospital stay 8, 9, 15, 14 and 11 d. Four patients received intraoperative blood transfusion of 300, 900, 150 and 1, 050 mL, respectively. One patient died of a heart attack 3 months after discharge; another patient developed dyskinesia at the contralateral limb 3 months after discharge due to cerebral infarction and died of recurrent cerebral infarction 7 months after discharge. At the last follow-up, the Harris hip scores of 3 patients were 86, 77 and 69 points, respectively. None of the patients had complications like breakage or loosening of implants.Conclusion:In the treatment of elderly patients with periprosthetic femoral fracture, fixation with a 3D printed individualized custom-made plate may lead to fine limb function and good short-term curative efficacy.

Objective:To explore the clinical efficacy of operative treatment of geriatric pelvic fractures.Methods:A retrospective study was conducted to analyze the clinical data of 55 geriatric patients with pelvic fracture who had been operatively treated at Department of Orthopaedic Trauma, Beijing Jishuitan Hospital from January 2020 to October 2023. There were 13 males and 42 females with an age of 72.0 (68.0, 83.3) years. By the AO/OTA classification, there were 47 cases of type B and 8 cases of type C; by the classification for fragility fractures of pelvis, there were 5 cases of type Ⅱ, 44 cases of type Ⅲ, and 6 cases of type Ⅳ. The patients received operative treatment 4.0 (3.0, 6.3) days after injury. Of the 10 patients treated by open reduction and closed reduction, the posterior ring was fixated by a plate in 7 and by screws in 3, and the anterior ring was fixated by either a plate, an external fixator or a minimally invasive anterior pelvic ring internal fixator except in the 2 cases receiving no fixation. Of the other 45 patients treated by closed reduction and fixation, the posterior ring was all fixated by screws except in the 2 cases receiving no fixation, and the anterior ring was fixated by either screws, an external fixator or a minimally invasive anterior pelvic ring internal fixator except in the 10 cases receiving no fixation. The major peri-operative complications, quality of fracture reduction, mortality, and functional recovery of the pelvis at the last follow-up were recorded.Results:There were no major peri-operative complications. According to the Matta criteria, the quality of fracture reduction was excellent in 31, good in 14, fair in 8 and poor in 2 cases, giving a good to excellent rate of 81.8% (45/55). Fifty-four cases were followed up for (15.4±9.1) months and 1 case was lost to the follow-up. Four cases died within 1 year after operation, giving a mortality of 7.4% (4/54). The modified Majeed score at the last follow-up was 69 (54, 76) for the 46 cases who had been followed up for longer than 4 months; the functional recovery of the pelvis at the last follow-up was rated as excellent in 27 cases, as good in 8 cases and as fair in 11 cases, giving a good to excellent rate of 76.1% (35/46) according to the criteria proposed by the faculty of the writers. The internal fixation failed in 3 cases during the follow-up.Conclusion:For the geriatric pelvic fractures, operative treatment can lead to satisfactory clinical outcomes.

Objective:To elucidate the recent therapeutic efficacy of the intelligent fracture reduction robotic system in managing pelvic fractures.Methods:A retrospective evaluation of 49 pelvic fracture patients treated using the intelligent fracture reduction robotic system at Beijing Jishuitan Hospital's trauma orthopedics department between March 2021 and December 2022 was conducted. The cohort included 30 males and 19 females, with a mean age of 51.51±18.71 years (20-92 years range). Fractures were classified according to the Tile system: B1 type in 2 cases, B2 in 7, B3 in 3, C1 in 30, and C2 in 3. The median interval between injury and surgery was 6 days, with a range of 2-22 days. The robotic system assisted in pelvic fracture reduction and stabilization surgeries. Preoperative and postoperative evaluations involved pelvic CT scans, anteroposterior, inlet, and outlet radiographic images. Fracture displacement and reduction outcomes were assessed via X-ray imagery. Data captured included intraoperative blood loss, duration of surgery, fracture stabilization techniques, and postoperative monitoring period. The Majeed scoring system gauged functional outcomes.Results:Of the patients, 48 underwent minimally invasive interventions with robotic assistance, while one case necessitated open reduction and internal fixation due to an unsuccessful reduction. The duration between injury and operation ranged from 2 to 22 days. Average surgical time stood at 206.5±7.1 minutes (105-440 min range), and median intraoperative blood loss was 100ml (10-600 ml range). Using the Matta reduction criteria, 30 postoperative cases exhibited excellent and 9 good outcomes for posterior pelvic ring displacement, translating to a 93% (38/41) positive rate. For anterior pelvic ring shifts, 45 showed excellent and 3 good outcomes, culminating in a 100% (48/48) success rate. Follow-up for the 48 cases lasted 11.0 months (3-23 months range), with the Majeed functional score averaging 81.9±17.0 points (42-100 point range). 27 cases scored excellent, and 11 good, yielding a combined positive outcome rate of 79.2% (38/48).Conclusion:Employing the intelligent fracture reduction robotic system in pelvic fracture treatments facilitates minimally invasive interventions and yields favorable short-term clinical results.

Objective: To establish a mouse model of psoriasis complicated by bone loss by long-term topical application of imiquimod. Methods: Twelve 10-week-old Kunming mice were randomly and equally divided into 2 groups: experimental group topically treated with 50 mg/d imiquimod cream every day on the shaved back, and control group topically treated with equivalent vaseline ointment every day on the shaved back. Skin manifestations were observed on the mouse back every day. The mice were sacrificed 10 weeks later. Before the sacrifice, the degree of erythema, scaling and skin thickening was evaluated, psoriasis area severity index (PASI) was calculated, mouse weight was measured, and eyeball blood was obtained. After the sacrifice, skin lesions on the back were resected and subjected to hematoxylin-eosin staining, so as to evaluate histological changes. Then, the left tibia was obtained from the mice, immunohistochemical staining was performed to observe the expression and distribution of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-β ligand (RANKL) in bone tissues, and micro-computerized tomography was conducted to determine the bone mass of spongy bone, and the bone volume-to-total volume ratio, number, thickness, spacing and connectivity density of the trabecular bone in the proximal tibia. The left femur was also obtained from the mice, and subjected to three-point bending test for evaluating its biomechanical properties. Enzyme-linked immunosorbent assay (ELISA) was performed to detect serum levels of tumor necrosis factor (TNF) -α and interleukin (IL) -17. RNA was extracted from the right tibia, and real-time PCR was conducted to determine the mRNA expression of OPG and RANKL. Two-independent-sample t test was used to compare the above indices between two groups. Results: Ten-week topical stimulation with imiquimod could lead to psoriasiform dermatitis on the mouse back, presenting as erythema, scales and skin thickening. The PASI score was significantly higher in the experimental group (9.167 ± 1.722) than in the control group (0, t = 13.31, P < 0.001) . Hematoxylin-eosin staining showed thickened spinous layer, extended rete ridges, infiltration of inflammatory cells in the superficial dermis, spongiosis, vasodilatation and increased hair follicles in the experimental group. Immunohistochemical staining revealed that the expression of OPG and RANKL was significantly higher in the experimental group (16 021.33 ± 1 954.61, 35 433.33 ± 1 197.95 respectively) than in the control group (3 307.00 ± 1 158.72, 13 644.67 ± 4 764.61, respectively; t = 9.692, 7.682 respectively, both P < 0.01) . Micro-computerized tomography showed that the bone volume-to-total volume ratio and thickness of trabecular bone in the proximal tibia were significantly lower in the experimental group than in the control group, but the spacing of trabecular bone was significantly higher in the experimental group than in the control group (P < 0.01 or < 0.05) . There were no significant differences in the elastic modulus and fracture energy of the femur between the experimental group and control group (both P > 0.05) . Moreover, no significant differences in the serum levels of TNF-α and IL-17 were observed between the two groups (both P > 0.05) . Real-time PCR revealed that the mRNA expression of OPG and RNAKL was significantly higher in the experimental group than in the control group (P < 0.05, < 0.01 respectively) . Conclusions Long-term topical application of imiquimod can not only induce psoriasiform dermatitis in mice, but also lead to bone loss of spongy bone and micro-architectural deterioration in the proximal tibia. Thus, mouse models of psoriasis complicated by bone loss can be established by long-term imiquimod stimulation.