Interpretable Machine Learning Model to Predict Bone Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fracture Based on SHapley Additive exPlanations.

STUDY DESIGN: Retrospective study. OBJECTIVES: Our objective is to create comprehensible machine learning (ML) models that can forecast bone cement leakage in percutaneous vertebral augmentation (PVA) for individuals with osteoporotic vertebral compression fracture (OVCF) while also identifying the associated risk factors. METHODS: We incorporated data from patients (n = 425) which underwent PVA. To predict cement leakage, we devised six models based on a variety of parameters. Evaluate and juxtapose the predictive performances relied on measures of discrimination, calibration, and clinical utility. SHapley Additive exPlanations (SHAP) methodology was used to interpret model and evaluate the risk factors associated with cement leakage. RESULTS: The occurrence rate of cement leakage was established at 50.4%. A binary logistic regression analysis identified cortical disruption (OR 6.880, 95% CI 4.209-11.246), the basivertebral foramen sign (OR 2.142, 95% CI 1.303-3.521), the fracture type (OR 1.683, 95% CI 1.083-2.617), and the volume of bone cement (OR 1.198, 95% CI 1.070-1.341) as independent predictors of cement leakage. The XGBoost model outperformed all others in predicting cement leakage in the testing set, with AUC of .8819, accuracy of .8025, recall score of .7872, F1 score of .8315, and a precision score of .881. Several important factors related to cement leakage were drawn based on the analysis of SHAP values and their clinical significance. CONCLUSION: The ML based predictive model demonstrated significant accuracy in forecasting bone cement leakage for patients with OVCF undergoing PVA. When combined with SHAP, ML facilitated a personalized prediction and offered a visual interpretation of feature importance.

Machine Learning Prediction Model and Risk Factor Analysis of Reoperation in Recurrent Lumbar Disc Herniation Patients After Percutaneous Endoscopic Lumbar Discectomy.

OBJECTIVE: To investigate the risk factors of reoperation after percutaneous endoscopic lumbar discectomy (PELD) due to recurrent lumbar disc herniation (rLDH) and to establish a set of individualized prediction models. METHODS: Patients who underwent PELD successfully from January 2016 to February 2022 in a single institution were enrolled in this study. Six methods of machine learning (ML) were used to establish an individualized prediction model for reoperation in rLDH patients after PELD, and these models were compared with logistics regression model to select optimal model. RESULTS: A total of 2603 patients were enrolled in this study. 57 patients had repeated operation due to rLDH and 114 patients were selected from the remaining 2546 nonrecurrent patients as matched controls. Multivariate logistic regression analysis showed that disc herniation type (P < .001), Modic changes (type II) (P = .003), sagittal range of motion (sROM) (P = .022), facet orientation (FO) (P = .028) and fat infiltration (FI) (P = .001) were independent risk factors for reoperation in rLDH patients after PELD. The XGBoost AUC was of 90.71%, accuracy was approximately 88.87%, sensitivity was 70.81%, specificity was 97.19%. The traditional logistic regression AUC was 77.4%, accuracy was about 77.73%, sensitivity was 47.15%, specificity was 92.12%. CONCLUSION: This study showed that disc herniation type (extrusion, sequestration), Modic changes (type II), a large sROM, a large FO and high FI were independent risk factors for reoperation in LDH patients after PELD. The prediction efficiency of XGBoost model was higher than traditional Logistic regression analysis model.

The efficacy and safety of using cooled radiofrequency in treating chronic sacroiliac joint pain: A PRISMA-compliant meta-analysis.

BACKGROUND: Cooled radiofrequency procedure is a novel minimally invasive surgical technique and has been occasionally utilized in managing chronic sacroiliac joint (SIJ) pain. A meta-analysis was conducted to systematically assess the efficacy and safety of using cooled radiofrequency in treating patients with chronic SIJ pain in terms of pain and disability relief, patients' satisfaction degree as well as complications. METHODS: Studies of using cooled radiofrequency procedure in managing SIJ pain were retrieved from Medline and Web of Science according to inclusion and exclusion criteria. Quality evaluation was conducted using Cochrane collaboration tool for randomized controlled trials and MINORS quality assessment for noncomparative trials. Statistics were managed using Review Manager 5.3. RESULTS: Totally 7 studies with 240 eligible patients were enrolled. The overall pooled results demonstrated that pain intensity decreased significantly after cooled radiofrequency procedure compared with that measured before treatment. The mean difference (MD) was 3.81 [95% confidence intervals (95% CIs): 3.29-4.33, P < .001] and 3.78 (95% CIs: 3.31-4.25, P < .001) as measured by the Numerical Rating Scale (NRS) and Visual Analog Scale (VAS), respectively. Disability also relieved significantly after treatment compared with that measured before treatment. The MD was 18.2 (95% CIs: 12.22-24.17, P < .001) as measured by the Oswestry Disability Index (ODI). Seventy-two percent of the patients presented positive results as measured by the Global Perceived Effect (GPE). The OR was 0.01 (95% CIs: 0.00-0.05, P < .001). Only mild complications were observed in the 7 studies, including transient hip pain, soreness, and numbness. CONCLUSION: Cooled radiofrequency procedure can significantly relieve pain and disability with no severe complications, and majority of patients are satisfied with this technique. Thus, it is safe and effective to use this procedure in managing patients with chronic SIJ pain. More high-quality and large-scale randomized controlled trials (RCTs) are required to validate our findings. LIMITATIONS: The sample size of the included studies was small and various heterogeneity existed.

Outcomes of Microendoscopic Discectomy and Percutaneous Transforaminal Endoscopic Discectomy for the Treatment of Lumbar Disc Herniation: A Comparative Retrospective Study.

STUDY DESIGN: Retrospective, case control evaluation of 86 patients who underwent microendoscopic discectomy (MED) and percutaneous transforaminal endoscopic discectomy (PTED) for the treatment of lumbar disc herniation (LDH). PURPOSE: To evaluate the safety and the outcomes of MED and PTED for the treatment of LDH. OVERVIEW OF LITERATURE: MED and PTED are minimally invasive surgical techniques for lower back pain. Studies to date have shown that MED and PTED are safe and effective treatment modalities for LDH. METHODS: A retrospective study was performed in patients with LDH treated with MED (n=50) and transforaminal endoscopic discectomy (PTED; n=36) in our hospital. All patients were followed-up with self-evaluation questionnaires, Oswestry disability index (ODI), medical outcomes study 36-item short form health survey and MacNab criteria. All the patients in both groups were followed up to 12 months after the operation. RESULTS: ODI questionnaire responses were not statistically different between the MED and PTED groups (53.00 vs. 48.72) before treatment. Average scores and minimal disability after 5 days to 12 months of follow-up were 4.96 in the MED group and 3.61 in the PTED group. According to MacNab criteria, 92.0% of the MED group and 94.4% of the PTED group had excellent or good results with no significant difference. CONCLUSIONS: There was no significant difference between MED and PTED outcomes. Further large-scale, randomized studies with long-term follow-up are needed.

Evaluation of intervertebral disc regeneration with implantation of bone marrow mesenchymal stem cells (BMSCs) using quantitative T2 mapping: a study in rabbits.

PURPOSE: The aim of the study was to investigate the curative effects of transplantation of bone marrow mesenchymal stem cells (BMSCs) on intervertebral disc regeneration and to investigate the feasibility of the quantitative T2 mapping method for evaluating repair of the nucleus pulposus after implantation of BMSCs. METHODS: Forty-eight New Zealand white rabbits were used to establish the lumber disc degenerative model by stabbing the annulus fibrosus and then randomly divided into four groups, i.e. two weeks afterwards, BMSCs or phosphate-buffered saline (PBS) were transplanted into degenerative discs (BMSCs group and PBS group), while the operated rabbits without implantation of BMSCs or PBS served as the sham group and the rabbits without operation were used as the control group. At weeks two, six and ten after operation, the T2 values and disc height indices (DHI) were calculated by magnetic resonance imaging (MRI 3.0 T), and the gene expressions of type II collagen (COL2) and aggrecan (ACAN) in degenerative discs were evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR). T2 values for the nucleus pulposus were correlated with ACAN or COL2 expression by regression analysis. RESULTS: Cell clusters, disorganised fibres, interlamellar glycosaminoglycan (GAG) matrix and vascularisation were observed in lumber degenerative discs. BMSCs could be found to survive in intervertebral discs and differentiate into nucleus pulposus-like cells expressing COL2 and ACAN. The gene expression of COL2 and ACAN increased during ten weeks after transplantation as well as the T2 signal intensity and T2 value. The DHI in the BMSCs group decreased more slowly than that in PBS and sham groups. The T2 value correlated significantly with the gene expression of ACAN and COL2 in the nucleus pulposus. CONCLUSIONS: Transplantation of BMSCs was able to promote the regeneration of degenerative discs. Quantitative and non-invasive T2 mapping could be used to evaluate the regeneration of the nucleus pulposus with good sensitivity.

New cage for posterior minimally invasive lumbar interbody fusion: a study in vitro and in vivo.

OBJECTIVE: To design a new type of interbody fusion device made of nickel titanium NiTi shape memory alloy and to compare segmental stiffness after various posterior lumbar interbody fusion (PLIF) procedures in vitro and in vivo. METHODS: Twelve sheep lumbar functional spinal units were randomly allocated to four groups. One acted as controls (N); the other three were treated with autogenous iliac crest bone dowel graft (L), a threaded cylindrical titanium (KC) interbody fusion device (TFC) or a new type of interbody fusion device made of NiTi shape memory alloy (NT) containing autogenous iliac crest graft. In addition, 15 sheep were allocated to three groups; one served as controls and the other two underwent TFC (KC) or NiTi-FC (NT). Nondestructive mechanical tests were performed in pure compression, extension, lateral bending and torsion. The operated spines were photographed regularly to assess changes in interbody height and degree of fusion. The animals were killed at 6 months for histologic testing. RESULTS: Biomechanical tests showed both the strength and axial stiffness of the NT and KC groups were significantly higher than those of the control group and L group (P < 0.05). When the mechanical performance in torque and torsion of each group were compared, the same results could be obtained. The maximal destructive load of the NiTi-TFC was 11 200 N and the safety coefficient was above 1.2. Radiological observations revealed that the bone callus around the interbody fusion device were gradually increased postoperatively (2 months, no obvious; 4 months, poorly define; 6 months, dense). The KC and NT group had lost 16% and 16.5% of their postoperative height but remained well above normal disc height (P < 0.05). Histologic examination showed new trabeculation connected with that of the host. CONCLUSION: The mechanical characteristics of the NiTi-TFC are excellent and it is safe and reliable.

Ex vivo observation of human nucleus pulposus chondrocytes isolated from degenerated intervertebral discs.

STUDY DESIGN: We performed an ex vivo study to observe cell morphology and viability of human nucleus pulposus (NP) chondrocytes isolated from degenerated intervertebral discs (IVD). PURPOSE: To better understand the biological behavior of NP chondrocytes in monolayer cultures. OVERVIEW OF LITERATURE: Biological repair of IVDs by cell-based therapy has been shown to be feasible in clinical trials. As one of the most promising transplanting seeds, how the isolated NP chondrocytes behavior ex vivo has not been fully understood. METHODS: Human NP chondrocytes were harvested from 20 degenerated IVDs and cultured in monolayers. Histological and immunochemistry staining was used to detect cell morphology change. Cell viability was studied by analyzing cell cycle distribution and apoptotic rate in the primary and subculuted cells. RESULTS: The round or polygonal primary NP chondrocytes had an average adherence time of 7 days and took nearly 31 days to reach 95% confluence. The spindle-shaped P1 NP chondrocytes increased growth kinetics and took about 12 hours to adhere and 6.6 days to get 95% confluent. Immunochemistry staining of collagen II was positive in the cell cytoplasm. Nearly 90% of the confluent NP chondrocytes stayed in G1 phase while 16% underwent apoptosis. No significant difference of the collagen II expression, cell cycle distribution or the apoptosis indices were detected between the primary and subcultured NP chondrocytes. CONCLUSIONS: Human NP chondrocytes undergo significant morphological change in monolayer cultures. Cell cycle distribution pattern and apoptosis index of the cutured NP chondrocytes potentially influence their clinical transplantation or laboratory use.

Long-term outcomes of patients with lumbar disc herniation treated with percutaneous discectomy: comparative study with microendoscopic discectomy.

We assessed the long-term outcomes of patients with lumbar disc herniation treated with percutaneous lumbar discectomy (PLD) or microendoscopic discectomy (MED). A retrospective study was performed in consecutive patients with lumbar disc herniation treated with PLD (n = 129) or MED (n = 101) in a single hospital from January 2000 to March 2002. All patients were followed up with MacNab criteria and self-evaluation questionnaires comprising the Oswestry Disability Index and Medical Outcomes Study 36-Item Short-Form Health Survey. Several statistical methods were used for analyses of the data, and a p value of <0.05 was considered to be statistically significant. A total of 104 patients (80.62%) with PLD and 82 patients (81.19%) with MED were eligible for analyses, with a mean follow-up period of 6.64 +/- 0.67 years and 6.42 +/- 0.51 years, respectively. There were no significant differences between the two groups in age, number of lesions, major symptoms and physical signs, and radiological findings. According to the MacNab criteria, 75.96% in the PLD group and 84.15% in the MED group achieved excellent or good results, respectively, this was statistically significant (p = 0.0402). With the Oswestry Disability Index questionnaires, the average scores and minimal disability, respectively, were 6.97 and 71.15% in the PLD group and 4.89 and 79.27% in the MED group. Total average scores of Medical Outcomes Study 36-Item Short-Form Health Survey were 75.88 vs. 81.86 in PLD group vs. MED group (p = 0.0582). The cost and length of hospitalization were higher or longer in MED group, a statistically significant difference (both p < 0.0001). Long-term complications were observed in two patients (2.44%) in the MED group, no such complications were observed in the PLD group. Both PLD and MED show an acceptable long-term efficacy for treatment of lumbar disc herniation. Compared with MED patients, long-term satisfaction is slightly lower in the PLD patients; complications, hospitalization duration, and costs in PLD group are also lower.

[Long-term outcomes of percutaneous lumbar discectomy and microendoscopic discectomy for lumbar disc herniation].

OBJECTIVE: To evaluate the long-term effects of percutaneous lumbar discectomy (PLD) and microendoscopic discectomy (MED) in treatment of lumbar disc herniation. METHODS: A questionnaire survey by letter and telephone was conducted among 104 patients undergoing PLD and 82 patients undergoing MED during January 2000 to March 2002, to investigate the Oswestry disability index (ODI), Short Form-36 (SF-36) score, and Japanese Orthopedic Association (JOA) score. RESULTS: The excellent/good rate (ODI score=0-20%) of the MED group was 79.27%, significantly higher than that of the PLD group (71.15%, P=0.0397). However, longer The hospitalization duration of the MED group was 11, 6 d, significantly longer than that of the PLD group (7.9 d, P<0.01), and the mean cost of the MED group was, significantly higher than that of the PLD group (P<0.01). Long-term complications were observed in 3 patients of the MED group (3.49%) while none in the PLD group. CONCLUSION: Both PLD and MED are minimally-invasive-technique with a long-term efficacy and safety on lumbar disc herniation. Although the long-term outcome of the MED group is better than PLD, the complication rate, hospitalization duration, and cost of the MED group are higher.