Percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of spinal metastases / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effectiveness of percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of patients with spinal metastases.@*METHODS@#In the study, 12 patients of spinal metastases treated with percutaneous pedicle screw fixation combined expandable tubular retractor in our hospital were retrospectively reviewed between June 2017 and October 2019. Among the 12 patients, 9 were males and 3 were females; the median age was 62.5 years [(65.1±2.9) years]. The decompression segment of 7 patients was located at the lower thoracic spine (including 1 patient with incomplete paraplegia) and the decompression segment of 5 patients was located at the lumbar spine; Tomita score was 6.0±0.6. Perioperative data of the patients were reviewed. Visual analog scale (VAS score), Karnofsky score, and Eastern Cooperative Oncology Group (ECOG) score were compared before and after surgery. The patient's survival, adjuvant treatment, and internal fixation failure were observed in the follow-up period.@*RESULTS@#All the 12 patients had a successful operation with percuta-neous pedicle screw fixation combined expandable tubular retractor. The average operative time, blood loss, and blood transfused of the patients were (247.0±14.6) min, (804.2±222.3) mL and (500.0±100.0) mL, respectively. The average amount of drainage was (240.8±79.3) mL. Drainage tubes were pulled out early postoperative [(3.2±0.3) d], allowing early mobilization. The patients discharged (7.8±0.8) d postoperative. All the patients were followed up for 6-30 months, and the average overall survival time was (13.6±2.4) months. During the follow-up period, 2 patients experienced screw displacement, the internal fixation was stable after conservative treatment and no revision surgery was performed. The VAS of the patients was 7.1±0.2 before surgery, which decreased to 2.3±0.1 and 2.8±0.4 at 3 and 6 months after surgery (P < 0.05). The Karnofsky score of the patients was 59.2±1.9 before surgery, which increased to 75.0±1.9 and 74.2±3.1 at 3 and 6 months after surgery (P < 0.05). The ECOG of the patients was 2.3±0.2 before surgery, which decreased to 1.7±0.1 and 1.7±0.2 at 3 and 6 months after surgery (P < 0.05).@*CONCLUSION@#For selected patients with spinal metastases, minimally invasive surgical treatment of spinal metastases (percutaneous pedicle screw internal fixation combined with expandable tubular retractor) can effectively relieve the clinical symptoms and improve the quality of life, with satisfactory clinical outcome.

Analysis of influencing factors for pathogen culture result in patients with pyogenic spondylitis / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effect of clinical factors on the pathogen culture results in the patients with pyogenic spondylitis, and to find out clinical controllable factors which could increase the positive rate of the pathogen culture.@*METHODS@#A retrospective study reviewed 40 patients who were diagnosed with pyogenic spondylitis in Peking University First Hospital from January 2011 to July 2017. The patients were divided into two groups depending on the culture results, culture negative or culture positive. The influence of clinical uncontrollable factors [the patient's age, gender, predisposing factors, infection site except spine, visual analogue score (VAS), course of disease, spinal segment, white blood cell (WBC), (neutrophilic granulocyte)% (NE%), the incidence of systemic inflammatory response syndrome (SIRS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the incidence of paravertebral abscess] and controllable factors (prior antibiotics exposure within 2 weeks, tissue homogenate, surgical approach) on pathogen culture results were analyzed.@*RESULTS@#Of the 40 patients, 18 patients were female and 22 patients were male. Causative germ was identified in 24/40 patients (60.00%) and dominant by gram positive cocci (68.00%). For clinical uncontrollable factors, there was no significant difference between the two groups in the patient's age, gender, predisposing factors, infection site except spine, VAS, course of disease, spinal segment, WBC, NE% and the incidence of SIRS. ESR [(94.38±6.91) mm/h, P=0.023)], CRP [(64.74±13.51) mg/L, P=0.040], and the incidence of paravertebral abscess (75%, P=0.018) in culture negative group were lower in contrast to culture positive group. For clinical controllable factors, prior antibiotics exposure within 2 weeks (P=0.058, OR=4.030, 95%CI: 0.956-16.993) and tissue homogenate (P=0.014, OR=0.171, 95%CI: 0.042-0.695) were significantly associated with the pathogen culture result. Surgical approach was not significantly associated with pathogen culture result.@*CONCLUSION@#Patients with high level of ESR, CRP, and paravertebral abscess, would have high positive rate of pathogenic culture. Prior antibiotics exposure was associated with lower positive pathogen culture rate. Culture with tissue homogenate was more likely to find the causative germ, especially for patients without paravertebral abscess who had low level of ESR, CRP and prior antibiotics exposure.

Perioperative clinical characteristics of patients with pathological fracture of proximal femur / 北京大学学报(医学版)

OBJECTIVE@#To investigate the perioperative clinical characteristics of patients with pathological fracture of proximal femur.@*METHODS@#A retrospective study reviewed 28 patients who received proximal resection and tumor hemiarthroplasty for malignant proximal femoral tumor in Peking University First Hospital from January 2011 to February 2017. According to the fracture, the patients were divided into two groups: pathological fracture group and non-pathological fracture group. We investigated the clinical characteristics during perioperative period between the two groups.@*RESULTS@#Of the 28 patients, 14 (50.0%) patients suffered pathological fracture, and there was no significant difference between the two groups in the patient's age, gender, limb involvement, and tumor source (P>0.05). There was no significant difference between the two groups in hemoglobin (HGB), hematocrit (Hct), and lower extremity thrombosis. The albumin (ALB) of pathological fracture group were lower in contrast to non-pathological fracture group (P=0.031). There was no significant difference between the two groups in decline of HGB and Hct on postoperation day 1, operative time, bleeding during operation, time for walking with help of ambulation aid postoperative, and postoperative hospital stay (P>0.05). On post-operation day 7, HGB (P=0.025) and Hct (P=0.039) of pathological fracture group were significant lower in contrast to non-pathological fracture group. Whereas, the total blood loss calculated by Gross equation of pathological fracture group was significant higher in contrast to non-pathological fracture group [(2 066.3±419.8) mL vs. (786.0±152.6) mL, P=0.039]. The patient needed blood transfusion during operation (7/14 vs. 1/14, P=0.033) and postoperative (8/14 vs. 1/14, P=0.013) in pathological fracture group were more than in non-pathological fracture group. At last, Barthel daily life ability score (P=0.009) of pathological fracture group was lower in contrast to non-pathological fracture group, and visual analogue scale (VAS) score was higher (P<0.001). They were almost equal when the patients were discharged (P>0.05).@*CONCLUSION@#Patients with pathological fracture had lower ALB during perioperative period. Pathological fracture had no effect on operative time, bleeding during operation and function outcomes. However, the patients with pathological fracture had more total blood loss and lower HGB, Hct in contrast to the patients without pathological fracture. Blood transfusion was more needed in pathological fracture patients.

Measurement of the tibial alignment after total knee replacement without the extramedullary cutting guide / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the accuracy and analysis of the influencing factors of the tibia prosthetic coronal alignment after total knee arthroplasty without tibia extramedullary cutting guide.@*METHODS@#In the study, 76 patients (96 knees) who had primary total knee arthroplasty in Peking University First Hospital from February 2012 to April 2016 were selected retrospectively. All of the cases were performed by the same experienced orthopedic surgeon team. The patients were divided into 2 groups randomly: tibia cutting without guide group and tibia cutting with extramedullary guide group. Lower extremity standard anterior and posterior X-ray films of the knees were taken before and after surgery, and the anatomical tibial angle (AT), the posterior slope angle (PSA) before and after surgery, the tibia component angle (TCA) were measured in the X-ray films. We also recorded the beginning and finishing time of the operation, the operation sequence of the day respectively at the same time. The data were analyzed by correlation analysis, t test and chi square test between the two groups.@*RESULTS@#The age, gender, body mass index, AT/PSA before the surgery and TCA/PSA after the surgery of the two groups were no significant differences (P>0.05). The rate of 90-TCA≥ 3° was 31.5% (17 knees) and 31% (12 knees) respectively, there were no significant differences (P=0.956) between the two groups. The postoperative TCA of two groups was not correlated with age, gender, body mass index (BMI), operation side (P>0.05), there was also no correlation between the postoperative TCA and the start time of the operation, the whole operation time, and the operation sequence of the day (P>0.05). The two groups were divided into subgroups according to 90-AT before the operation (0°≤90-AT<3°, 3°≤90-AT<5°, 5°≤90-AT<8°, 90-AT≥8°), and there was no difference among them. But we found there was a much higher rate of 90-TCA<3° in the group without cutting guide than the group with extramedullary guide when 90-AT≥8° before the surgery (the rates were 71.4 % and 42.9%, P<0.05).@*CONCLUSION@#There is no significant difference of the tibia prosthetic coronal alignment accuracy between the tibia cutting without guide and the traditional extramedullary guided bone cutting by experienced surgeons. Only if when patients already have suffered severe malformation of knee joint (90-AT≥8°) before the operation, tibia cutting without cutting guide is more effective to rectify the tibia prosthetic coronal alignment.

Intraarticular Injection of Allogenic Mesenchymal Stem Cells has a Protective Role for the Osteoarthritis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Researchers initially proposed the substitution of apoptotic chondrocytes in the superficial cartilage by injecting mesenchymal stem cells (MSCs) intraarticularly. This effect was termed as bio-resurfacing. Little evidence supporting the treatment of osteoarthritis (OA) by the delivery of a MSC suspension exists. The aim of this study was to investigate the effects of injecting allogenic MSCs intraarticularly in a rat OA model and to evaluate the influence of immobility on the effects of this treatment.</p><p><b>METHODS</b>We established a rat knee OA model after 4 and 6 weeks and cultured primary bone marrow MSCs. A MSC suspension was injected into the articular space once per week for 3 weeks. A subgroup of knee joints was immobilized for 3 days after each injection, while the remaining joints were nonimmobilized. We used toluidine blue staining, Mankin scores, and TdT-mediated dUTP-biotin nick end labeling staining to evaluate the therapeutic effect of the injections. Comparisons between the therapy side and the control side of the knee joint were made using paired t-test, and comparisons between the immobilized and nonimmobilized subgroups were made using the unpaired t-test. A P value < 0.05 was considered significant.</p><p><b>RESULTS</b>The three investigative approaches revealed less degeneration on the therapy sides of the knee joints than the control sides in both the 4- and 6-week groups (P < 0.05), regardless of immobilization. No significant differences were observed between the immobilized and nonimmobilized subgroups (P > 0.05).</p><p><b>CONCLUSIONS</b>Therapy involving the intraarticular injection of allogenic MSCs promoted cartilage repair in a rat arthritis model, and 3-day immobility after injection had little effect on this therapy.</p>