A Suture Technique for Ruptured Annulus Fibrosus Following Decompression Under Percutaneous Transforaminal Endoscopic Discectomy.

The suture technique for a ruptured annulus fibrosus (AF) under full-endoscopy remains challenging. Direct suturing of a ruptured annular tear after full decompression has been shown to decrease the recurrence rate of lumbar disc herniation during endoscopic surgery. Traditional suture operations under endoscopy involve only simple suturing of the ruptured AF. Due to the weak and poor quality of the AF tissue around the tear portal, using this area as needle insertion points during suturing may lead to insufficient tension and a low success rate of AF closure. Currently, there is no detailed technical illustration based on video for AF tear suturing under lumbar full-endoscopy. We innovatively propose a method of covering and suturing the AF tear by pulling up the posterior longitudinal ligament (PLL) under lumbar endoscopy and using three stitches (PLL-AF suture technique). The patient who received the novel suture technique achieved satisfactory results. Six months after the operation, lumbar MRI showed no evidence of recurrence in the outpatient clinic.

Prevalence and risk factors of bone metastasis and the development of bone metastatic prognostic classification system: a pan-cancer population study.

BACKGROUND: The prevalence of bone metastasis (BM) varies among primary cancer patients, and it has a significant impact on prognosis. However, there is a lack of research in this area. This study aims to explore the clinical characteristics, prevalence, and risk factors, and to establish a prognostic classification system for pan-cancer patients with BM. METHODS: The data obtained from the Surveillance, Epidemiology and End Results database were investigated. The prevalence and prognosis of patients with BM were analyzed. Hierarchical clustering was used to develop a prognostic classification system. RESULTS: From 2010 to 2019, the prevalence of BM has increased by 41.43%. BM most commonly occurs in cancers that originate in the adrenal gland, lung and bronchus and overlapping lesion of digestive systems. Negative prognostic factors included older age, male sex, poorer grade, unmarried status, low income, non-metropolitan living, advanced tumor stages, previous chemotherapy, and synchronous liver, lung, and brain metastasis. Three categories with significantly different survival time were identified in the classification system. CONCLUSIONS: The clinical features, prevalence, risk factors, and prognostic factors in pan-cancer patients with BM were investigated. A prognostic classification system was developed to provide survival information and aid physicians in selecting personalized treatment plans for patients with BM.

Association of age and spinopelvic function in patients receiving a total hip arthroplasty.

Restricted spinopelvic mobility received attention as a contributing factor for total hip arthroplasty (THA) instability. However, it is still unknown, how the spinopelvic function is influenced by age. In identifying the patients at highest risk for altered spinopelvic mechanics the study aimed to determine the association of age on the individual segments of the spinopelvic complex and global spinal sagittal alignment in patients undergoing THA. 197 patients were included in the prospective observational study conducting biplanar stereoradiography (EOS) in standing and sitting position pre-and postoperatively. Two independent investigators assessed C7-sagittal vertical axis (C7-SVA), cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA). Key segments of the spinopelvic complex are defined as lumbar flexibility (∆ LL = LLstanding - LLsitting), pelvic mobility (∆ SS = SSstanding - SSsitting) and hip motion (∆ PFA = PFAstanding - PFAsitting). Pelvic mobility was further defined based on ∆ SS = SSstanding - SSsitting as stiff (∆ SS < 10°), normal (∆ SS ≥ 10°-30°) and hypermobile (∆ SS > 30°). The patient collective was classified into three groups: (1) < 60 years (n = 56), (2) ≥ 60-79 years (n = 112) and (3) ≥ 80 years (n = 29). Lumbar flexibility (∆ LL) was decreased with increasing age between all groups (36.1° vs. 23.1° vs. 17.2°/p1+2 < 0.000, p2+3 = 0.020, p1+3 < 0.000) postoperatively. Pelvic mobility (∆ SS) was decreased in the groups 2 and 3 compared to group 1 (21.0° and 17.9° vs. 27.8°/p1+2 < 0.000, p2+3 = 0.371, p1+3 = 0.001). Pelvic retroversion in standing position (APPT) was higher in group 2 and 3 compared to group 1 (1.9° and - 0.5° vs 6.9°/p1+2 < 0.000, p2+3 = 0.330, p1+3 < 0.000). Global sagittal spinal balance (C7-SVA) showed more imbalance in groups 2 and 3 compared to group 1 (60.4 mm and 71.2 mm vs. 34.5 mm/p1+2 < 0.000, p2+3 = 0.376, p1+3 < 0.000) postoperatively. The preoperative proportion of patients with stiff pelvic mobility in group 1 was distinctly lower than in group 3 (23.2% vs. 35.7%) and declined in group 1 to 1.8% compared to 20.7% in group 3 after THA. Changes after THA were reported for groups 1 and 2 representing spinopelvic complex key parameter lumbar flexibility (∆ LL), pelvic mobility (∆ SS) and hip motion (∆ PFA), but not for group 3. This is the first study to present age-adjusted normative values for spinopelvic mobility. The subgroups with increased age were identified as risk cohort for altered spinopelvic mechanics and enhanced sagittal spinal imbalance and limited capacity for improvement of mobility after THA. This valuable information serves to focus in the preoperative screening on the THA candidates with the highest risk for abnormal spinopelvic function.

Hip replacement improves lumbar flexibility and intervertebral disc height - a prospective observational investigation with standing and sitting assessment of patients undergoing total hip arthroplasty.

PURPOSE: The pathogenic mechanism of the hip-spine syndrome is still poorly elucidated. Some studies have reported a reduction in low back pain after total hip arthroplasty (THA). However, the biomechanical mechanisms of THA acting on the lumbar spine are not well understood. The aim of the study is to evaluate the influence of THA on (1) the lumbar lordosis and the lumbar flexibility and (2) the lumbar intervertebral disc height. METHODS: A total of 197 primary THA patients were prospectively enrolled. Pre- and post-operative biplanar stereoradiography was performed in standing and sitting positions. Spinopelvic parameters (lumbar lordosis (LL), pelvic tilt, sacral slope, pelvic incidence), sagittal spinal alignment (sagittal vertical axis, PI-LL mismatch (PI-LL)) and lumbar disc height index (DHI) for each segment (L1/2 to L5/S1) were evaluated. The difference between standing and sitting LL (∆LL = LLstanding - LLsitting) was determined as lumbar flexibility. Osteochondrosis intervertebralis was graded according to Kellgren and Lawrence (0-4), and patients were assigned to subgroups (mild: 0-2; severe: 3-4). RESULTS: Lumbar flexibility increased significantly after THA (pre: 22.04 ± 12.26°; post: 25.87 ± 12.26°; p < 0.001), due to significant alterations in LL in standing (pre: 51.3 ± 14.3°; post: 52.4 ± 13.8°; p < 0.001) and sitting (pre: 29.4 ± 15.4°; post: 26.7 ± 15.4°; p = 0.01). ∆LL increased significantly in both subgroups stratified by osteochondrosis (pre/post: ΔLLmild: 25.4 (± 11.8)/29.4 ± 12.0°; p < 0.001; ΔLLsevere: 17.5 (± 11.4)/21.0 ± 10.9°; p = 0.003). The DHI increased significantly from pre-operatively to post-operatively in each lumbar segment. PI-LL mismatch decreased significantly after THA (pre: 3.5°; post: 1.4°; p < 0.001). CONCLUSION: The impact of THA on the spinopelvic complex was demonstrated by significantly improved lumbar flexibility and a gain in post-operative disc height. These results illustrate the close interaction between the pelvis and the vertebral column. The investigation provides new insights into the biomechanical patterns influencing the hip-spine syndrome.

Effect of Coronal and Sagittal Spinal Malalignment on Spinopelvic Mobility in Patients Undergoing Total Hip Replacement: A Prospective Observational Study.

STUDY DESIGN: This was a prospective observational study. OBJECTIVE: This investigation aimed (1) to determine the impact of sagittal spinal alignment with C7-sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL) mismatch and Roussouly classification on individual segments of spinopelvic mobility represented by lumbar flexibility [∆lumbar lordosis (LL)], pelvic mobility [∆pelvic tilt (PT)], and hip motion [∆pelvic femoral angle (PFA)] and (2) to assess the influence of coronal spinal balance on the spinopelvic complex in patients undergoing total hip arthroplasty (THA) preoperatively and postoperatively. SUMMARY OF BACKGROUND DATA: Restricted spinopelvic mobility gained attention as a contributing factor for THA instability. However, it remains unclear what influence the coronal and sagittal spinal alignment has on spinopelvic mobility. MATERIALS AND METHODS: A total of 197 THA patients were included in the investigation conducting biplanar stereoradiography in standing and sitting position preoperatively and postoperatively. Two independent investigators assessed C7-SVA (≤50 mm balanced, >50 mm imbalanced), PI-LL (≤10 degrees balanced, >10 degrees imbalanced), refounded Roussouly classification, coronal spinal balance with C7-central sacral vertical line, LL, pelvic incidence (PI), PT, PFA. Individual segments of spinopelvic mobility based on the change from standing to sitting were defined as ∆LL, ∆PT, and ∆PFA. Unpaired t test or Welch t test for comparison between groups of 2 was applied. Analysis of variance and post hoc analysis according to Bonferroni or Games-Howell was used to determine differences between groups of >2. The Spearman rank correlation coefficient was used to determine the interrater reliability of the radiographic measurements. RESULTS: Significant differences were demonstrated for ∆LL (SVA balanced/imbalanced: 24.7 degrees/19.1 degrees, P =0.001; PI-LL balanced/imbalanced: 24.4 degrees/16.4 degrees, P <0.000), PT (SVA balanced/imbalanced: 12.5 degrees/15.2 degrees, P =0.029; PI-LL balanced/imbalanced: 10.8 degrees/20.5 degrees, P <0.000), PI (SVA balanced/imbalanced: 52.9 degrees/56.9 degrees, P =0.001; PI-LL balanced/imbalanced: 52.1 degrees/61.0 degrees, P <0.000), LL (SVA balanced/imbalanced: 54.8 degrees/47.8 degrees, P =0.029; PI-LL balanced/imbalanced: 55.3 degrees/42.6 degrees, P <0.000). The coronal spinal balance (central sacral vertical line) indicated no significant differences regarding spinopelvic mobility between positive, neutral, or negative balanced groups. Significant differences with decreased pelvic mobility (∆PT) and lumbar flexibility (∆LL) in low-grade PI types 1 and 2 compared with high-grade PI type 4 according to the Roussouly classification were observed. CONCLUSIONS: This is the first study to investigate spinal sagittal alignment using 3 different classifications in association to the spinopelvic complex in THA patients preoperatively and postoperatively. The significantly altered spinopelvic mechanics with decreased lumbar flexibility and increased pelvic retroversion in sagittal imbalanced patients clearly indicate the need for a separate consideration of the global spinal sagittal alignment. Our findings emphasize the importance of risk stratification for THA candidates in terms of sagittal imbalance attempting to mitigate the THA instability risk with accurate preoperative planning. LEVEL OF EVIDENCE: Level III.

Does Total Hip Arthroplasty Affect Spinopelvic and Spinal Alignment?: A Prospective Observational Investigation.

STUDY DESIGN: A prospective observational study, level of evidence 3. OBJECTIVES: The study with patients undergoing unilateral total hip arthroplasty (THA) aimed to evaluate the following hypotheses: (1) the spinal sagittal and coronal alignment alters due to THA, (2) the spinopelvic parameter changes after THA, (3) the spinopelvic alignment differs between sagittal balanced and imbalanced patients. SUMMARY OF BACKGROUND DATA: Surgical correction of spinal sagittal misalignment affects the spinopelvic alignment and pelvic tilt. It is not yet known to what extent THA affects spinopelvic, spinal sagittal, and coronal alignment. MATERIALS AND METHODS: A total of 153 patients undergoing THA were assessed with biplanar stereoradiography in standing position preoperatively and postoperatively. Two independent investigators examined C7-sagittal vertical axis (C7-SVA), pelvic incidence-lumbar lordosis (PI-LL) mismatch, lumbar lordosis (LL), C7-central sacral vertical line, pelvic oblique angle lumbosacral, intra-pelvic oblique angle, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA). An analysis of the sagittal misaligned subgroups of C7-SVA and PI-LL on the influence of the spinopelvic alignment was performed. RESULTS: A significant difference in spinopelvic parameters was detected in the preoperative to postoperative comparison (SS, PT, APPT, and PFA; P <0.000) ( d =-0.394; d =0.609; d =-0.481; d =0.431). The coronal alignment and pelvic obliquity revealed no significant differences. The misaligned groups (C7-SVA; PI-LL) demonstrated significant increases in PI and PT and decreased in LL compared with the groups with normal sagittal alignment. Preoperatively, 66/153 (C7-SVA) and 46/153 (PI-LL) of the THA patients presented sagittal misalignment, respectively. CONCLUSIONS: The results suggest an effect of THA on sagittal spinal and spinopelvic alignment, with a significant reduction of PT postoperatively and no effect on coronal alignment. Particularly striking are the significant differences in the misaligned groups, which may be classified as risk population and potentially can contribute biomechanically to a higher risk of posterior impingement and anterior THA dislocation. The substantial proportion of sagittal misaligned patients in the THA collective illustrates the crucial need for interdisciplinary collaboration.

Spinopelvic mobility is influenced by pre-existing contralateral hip arthroplasty: a matched-pair analysis in patients undergoing hip replacement.

BACKGROUND: Spinopelvic mobility gained increased attention as a contributing factor for total hip arthroplasty (THA) instability. However, it is unknown how a pre-existing THA affects spinopelvic mobility. Therefore, a propensity-score-matched analysis of primary THA patients comparing the individual segments of spinopelvic mobility between patients with pre-existing THA and no-existing THA was conducted. Consequently, the study aimed to discuss (1) whether patients with a pre-existing THA have altered spinopelvic mobility compared to the control group and (2) if spinopelvic mobility changes after THA. METHODS: A prospective observational study enrolled 197 elective primary THA patients, including N = 44 patients with a pre-existing unilateral THA. Using propensity-score matching adapted for age, sex, and BMI, N = 44 patients without a pre-existing THA were determined. The patients received stereoradiography in standing and relaxed sitting position pre- and postoperatively. Assessed parameters were lumbar lordosis (LL), pelvic tilt (PT), and pelvic femoral angle (PFA). Key parameters of the spinopelvic mobility were defined as lumbar flexibility (∆LL = LLstanding - LLsitting), pelvic mobility (∆PT = PTstanding - PTsitting) and hip motion (∆PFA = PFAstanding - PFAsitting). Pelvic mobility was classified as stiff (∆PT < 10°), normal (∆PT ≥ 10°-30°) and hypermobile (∆PT > 30°). The Wilcoxon rank sum test for dependent samples was used. RESULTS: Pelvic mobility was significantly increased in the pre-existing THA group (∆PT 18.2° ± 10.7) compared to the control group (∆PT 7.7° ± 8.0; p < 0.001) preoperatively and postoperatively (pre-existing: 22.2° ± 9.3; control: 17.0° ± 9.2, p = 0.022). Lumbar flexibility was significantly increased in the pre-existing THA group (∆LL 21.6° ± 11.8) compared to the control group (∆LL 12.4° ± 7.8; p < 0.001) preoperatively and postoperatively (pre-existing: 25.7° ± 11.0; control: 19.0° ± 10.2; p = 0.011). The contribution of stiff pelvic mobility is distinctly smaller in the pre-existing THA group (25%) than in the control group (75%) preoperatively. CONCLUSIONS: Pre-existing THA is associated with significantly enhanced pelvic mobility and lumbar flexibility. Accordingly, we identified the patients without a pre-existing THA as risk candidates with higher likelihood for pathological spinopelvic mobility. This information will assist arthroplasty surgeons in deciding which THA candidates require preoperative radiological screening for pathologic spinopelvic mobility. LEVEL OF EVIDENCE: Level II prospective cohort study.

Acetabular cup position differs in spinopelvic mobility types: a prospective observational study of primary total hip arthroplasty patients.

INTRODUCTION: Spinopelvic mobility was identified as a contributing factor for total hip arthroplasty (THA) instability. The influence of spinopelvic function on acetabular cup positioning has not yet been sufficiently investigated in a prospective setting. Therefore, our study aimed (1) to assess cup inclination and anteversion in standing and sitting based on spinopelvic mobility, (2) to identify correlations between cup position and spinopelvic function, (3) and to determine the influence of the individual spinal segments, spinal sagittal balance, and spinopelvic characteristics on the mobility groups. MATERIALS AND METHODS: A prospective study assessing 197 THA patients was conducted with stereoradiography in standing and sitting position postoperatively. Two independent investigators determined cup anteversion and inclination, C7-Sagittal vertical axis, cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope, pelvic tilt (PT), anteinclination (AI), and pelvic femoral angle (PFA). Spinopelvic mobility is defined based on ∆PT = PTstanding - PTsitting as ∆PT < 10° stiff, ∆PT ≥ 10-30° normal, and ∆PT > 30° hypermobile. Pearson coefficient represented correlations between the cup position and spinopelvic parameters. RESULTS: Significant differences were demonstrated for cup anteversion (stiff/hypermobile 29.3°/40.1°; p < 0.000) and inclination (stiff/hypermobile 43.5°/60.2°; p < 0.000) in sitting, but not in standing position. ∆ (standing/sitting) of the cup anteversion (stiff/neutral/hypermobile 5.8°/12.4°/19.9°; p < 0.000) and inclination (stiff/neutral/hypermobile 2.3°/11.2°/18.8°; p < 0.000) revealed significant differences between the mobility groups. The acetabular cup position in sitting, was correlated with lumbar flexibility (∆LL) and spinopelvic mobility. Significant differences were detected between the mobility types and acetabular orientation (AI sit:stiff/hypermobile 47.6°/65.4°; p < 0.000) and hip motion (∆PFA:stiff/hypermobile 65.8°/37.3°; p < 0.000). Assessment of the spinal segments highlighted the role of lumbar flexibility (∆LL:stiff/hypermobile 9.9°/36.2°; p < 0.000) in the spinopelvic complex. CONCLUSION: The significantly different acetabular cup positions in sitting and in the ∆ between standing and sitting and the significantly altered spinopelvic characteristics in terms of stiff and hypermobile spinopelvic mobility underlined the consideration for preoperative functional radiological assessment. Identifying the patients with altered spinopelvic mechanics due to a standardized screening algorithm is necessary to provide safe acetabular cup positioning. The proximal spinal segments appeared not to be involved in the spinopelvic function.

Relationship Between the OF Classification and Radiological Outcome of Osteoporotic Vertebral Fractures After Kyphoplasty.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The OF classification is a new classification for osteoporotic vertebral fractures. The aim of this study was to clarify the relationship between preoperative OF subgroups and the postoperative outcome after kyphoplasty in patients with such fractures. METHODS: Patients who underwent kyphoplasty of a single osteoporotic vertebral fracture were included and divided into groups according to the OF subgroups. Pre- and postoperative plain radiographs were analyzed in regard to the restoration of vertebral body height and local kyphotic angle (LKA). Additionally, clinical data including pre- and postoperative Visual Analogue Scale pain scores was documented. The clinical and radiological results were compared pre- and postoperatively within groups and between groups. RESULTS: A total of 156 patients from OF subgroups 2 to 4 were included (OF 2: n = 58; OF 3: n = 36; OF 4: n = 62). Patients from all groups experienced significant pain relief postoperatively (P < .001). Patients with OF 2 fractures showed a repositioning of the vertebral body height in the anterior and middle portions (both P < .001), but no significant improvement in LKA. For OF 3 and 4 fractures, there was a significant restoration of vertebral body height (P < .001 for both) and a significant improvement of LKA (P < .001 for both). The highest average restoration was noted in the OF 4 group. CONCLUSIONS: A higher OF subgroup is related to a higher radiological benefit from kyphoplasty. This confirms that the OF classification is an appropriate tool for the preoperative assessment of osteoporotic fractures.

Total Hip Replacement Influences Spinopelvic Mobility: A Prospective Observational Study.

BACKGROUND: Abnormal spinopelvic mobility is identified as a contributing element of total hip arthroplasty (THA) instability. Preoperative identification of THA patients at risk is still a remaining challenge. We therefore conducted this study to (1) evaluate if preoperative and postoperative spinopelvic mobility differs, (2) determine the interactions between the elements of the spinopelvic complex, and (3) identify preoperative parameters for predicting spinopelvic mobility. METHODS: A prospective observational study assessing 197 THA patients was conducted with biplanar stereoradiography in standing and relaxed sitting positions preoperatively and postoperatively. Two independent investigators determined spinopelvic mobility based on 2 different classifications (Δ sacral slope [SS] and Δ pelvic tilt [PT]; Δ from standing to sitting; Δ < 10° stiff, Δ ≥ 10°-30° normal, Δ > 30° hypermobile). Multiple regression analysis and receiver operating characteristic analysis were used to identify predictors for postoperative spinopelvic mobility. RESULTS: Spinopelvic mobility significantly increased after THA based on ΔPT (Pre/Post: 18.5°/22.8°; P < .000) and ΔSS (Pre/Post 17.9°/22.4°; P < .000). A distinct shift in the ratio from stiff (Pre/Post: 24%/9.7%) to hypermobile (Pre/Post: 10.2%/22.1%) mobility postoperatively was observed. Receiver operating characteristic analysis predicted postoperative stiffness using preoperative PTStanding ≥ 13.0° with a sensitivity of 90% and a specificity of 51% and hypermobility with preoperative SSStanding ≥ 35.2° with a sensitivity of 81% and a specificity of 34%. Age at surgery, preoperative PTStanding, and pelvic incidence were independent predictors of spinopelvic mobility (R2 = 0.24). CONCLUSION: Definition of preoperative stiffness should be interpreted with caution by arthroplasty surgeons as mobility itself is influenced by THA. For the first time thresholds for standing preoperative parameters for predicting postoperative spinopelvic mobility could be provided. For preoperative standing only lateral assessment could serve as a screening tool for spinopelvic mobility.

Cooling Kinetic Characteristics of Temperature Difference between Cadaver Temperature and Ambient Temperature.

OBJECTIVES: To study the cooling reaction kinetic characteristics of the temperature difference between cadaver temperature and ambient temperature (hereinafter referred to as "cadaver temperature difference") according to the reaction kinetics method. METHODS: Thirty rabbits were randomly divided into 5 groups with 6 rabbits in each group. The rabbits were injected with 10% potassium chloride solution intravenously. After death, the rabbits were placed at 5 ℃, 10 ℃, 15 ℃, 20 ℃ and 25 ℃ environment condition, respectively, and the rectal temperature was measured every minute for 20 hours. The measured cadaver temperature was subtracted from ambient temperature, and the cadaver temperature difference data was calculated using the reaction kinetics formula. The linear regression equation was fitted for analysis, and the experimental results were applied to the temperature difference data of human body after death for verification. RESULTS: Under different environmental conditions, the linear coefficient determination of temperature difference -ln(C/C0) in rabbits was 0.99, showing a good linear relationship with time t. The application of human body temperature data after death was consistent with the results of animal experiments. CONCLUSIONS: Under stable conditions, the temperature difference cooling process after death in rabbits is a first-order kinetic response. The method can also be used to study the temperature difference in human body after death.

Does obesity affect acetabular cup position, spinopelvic function and sagittal spinal alignment? A prospective investigation with standing and sitting assessment of primary hip arthroplasty patients.

BACKGROUND: Total hip arthroplasty (THA) instability is influenced by acetabular component positioning, spinopelvic function and sagittal spinal alignment. Obesity is considered as a risk factor of THA instability, but the causal relationship remains unknown. This study aimed to investigate the influence of BMI on (1) spinopelvic function (lumbar flexibility, pelvic mobility and hip motion), (2) sagittal spinal alignment pre- and postoperatively and (3) acetabular cup position postoperatively in primary THA patients in a prospective setting. METHODS: One hundred ninety patients receiving primary total hip arthroplasty were enrolled in a prospective cohort study and retrospectively analysed. All patients received stereoradiography (EOS) in standing and relaxed sitting position pre-and postoperatively. C7-sagittal vertical axis (C7-SVA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), anterior plane pelvic tilt (APPT), and pelvic femoral angle (PFA) were assessed. Key parameters of the spinopelvic function were defined as lumbar flexibility (∆ LL = LLstanding - LLsitting), pelvic mobility (∆ PT = PTstanding - PTsitting) and hip motion (∆ PFA = PFAstanding - PFAsitting). Pelvic mobility was further defined based on ∆ PT as stiff, normal and hypermobile (∆ PT < 10°; 10°-30°; > 30°). The patients were stratified to BMI according to WHO definition: normal BMI ≥ 18.5-24.9 kg/m2 (n = 68), overweight ≥ 25.0-29.9 kg/m2 (n = 81) and obese ≥ 30-39.9 kg/m2 (n = 41). Post-hoc analysis according to Hochberg's GT2 was applied to determine differences between BMI groups. RESULTS: Standing cup inclination was significant higher in the obese group compared to the normal BMI group (45.3° vs. 40.1°; p = 0.015) whereas standing cup anteversion was significantly decreased (22.0° vs. 25.3°; p = 0.011). There were no significant differences for spinopelvic function key parameter lumbar flexibility (∆ LL), pelvic mobility (∆ PT) and hip motion (∆ PFA) in relation to BMI stratified groups. The obese group demonstrated significant enhanced pelvic retroversion compared to the normal BMI group (APPT - 1.8° vs. 2.4°; p = 0.028). The preoperative proportion of stiff pelvic mobility was decreased in the obese group (12.2%) compared to normal (25.0%) and overweight (27.2%) groups. Spinal sagittal alignment in C7-SVA and PI-LL mismatch demonstrated significantly greater imbalance in the obese group compared to the normal BMI group (68.6 mm vs. 42.6 mm, p = 0.002 and 7.7° vs. 1.2°, p = 0.032, respectively) The proportion of patients with imbalanced C7-SVA was higher in the obese (58.5%) than in the normal BMI group (44.1%). CONCLUSIONS: The significantly increased spinal sagittal imbalance with altered pelvic mechanics is a potential cause for the reported increased risk of THA dislocations in obese patients. Consequently, the increased spinal sagittal imbalance in combination with normal pelvic mobility need to be taken into account when performing THA in obese patients.

Intraoperative blood loss as indicated by haemoglobin trend is a predictor for the development of postoperative spinal implant infection-a matched-pair analysis.

BACKGROUND: With a reported rate of 0.7-20%, postoperative spinal implant infection (PSII) is one of the most common complications after spine surgery. While in arthroplasty both haematoma formation and perioperative blood loss have been identified as risk factors for developing periprosthetic joint infections and preoperative anaemia has been associated with increased complication rates, literature on the aetiology of PSII remains limited. METHODS: We performed a matched-pair analysis of perioperative haemoglobin (Hb) and haematocrit (Hct) levels in aseptic and septic spine revision surgeries. 317 patients were included, 94 of which were classified as septic according to previously defined criteria. Patients were matched according to age, body mass index, diabetes, American Society of Anesthesiologists score and smoking habits. Descriptive summaries for septic and aseptic groups were analysed using Pearson chi-squared for categorical or Student t test for continuous variables. RESULTS: Fifty patients were matched and did not differ significantly in their reason for revision, mean length of hospital stay, blood transfusion, operating time, or number of levels operated on. While there was no significant difference in preoperative Hb or Hct levels, the mean difference between pre- and postoperative Hb was higher in the septic group (3.45 ± 1.25 vs. 2.82 ± 1.48 g/dL, p = 0.034). CONCLUSIONS: We therefore show that the intraoperative Hb-trend is a predictor for the development of PSII independent of the amount of blood transfusions, operation time, number of spinal levels operated on and hospital length of stay, which is why strategies to reduce intraoperative blood loss in spine surgery need to be further studied.

Influence of operative timing on the early post-operative radiological and clinical outcome after kyphoplasty.

PURPOSE: To clarify the relationship between operative timing and the early post-operative radiological and clinical outcome after kyphoplasty. METHODS: We conducted a retrospective cohort study including patients who underwent kyphoplasty of a single vertebra. Patients were divided into three groups (acute [< 2 weeks], subacute [2-6 weeks] or chronic [6-51 weeks]) based on the interval between fracture and surgery. The relative vertebral body height (VBH) and local kyphotic angle (LKA) of the fractured vertebra (measured on plain radiographs) as well as pain and use of analgesics were compared pre- and post-operatively (day 2) and between the groups. RESULTS: A total of 230 patients (100 with acute, 91 with subacute and 39 with chronic fractures) with fractures from T4 to L5 were included. In all groups, there was a significant post-operative improvement in the anterior (8.9-12.9%) and middle (10.7-13.4%) VBH (all groups: p < 0.001), LKA (acute: 3.8°, p < 0.001; subacute: 4.3°, p < 0.001; chronic: 1.7°, p = 0.046) and pain. The use of analgesics significantly decreased post-operatively in the acute and subacute groups, but did not significantly change in the chronic group. Patients from acute (p = 0.042) and subacute (p = 0.027) groups showed significantly better post-operative correction of the LKA than the chronic group. CONCLUSION: Kyphoplasty is effective for vertebral height restoration as well as pain relief for both acute, subacute and chronic fractures. However, the achievable correction of the fracture-related local kyphosis decreases significantly after 6 weeks. Therefore, we recommend making a final decision about conservative vs. operative treatment within 6 weeks to ensure better height restoration in surgically treated patients.

Intervertebral disc degeneration in mice with type II diabetes induced by leptin receptor deficiency.

BACKGROUND: The leptin receptor-deficient knockout (db/db) mouse is a well-established model for studying type II diabetes mellitus (T2DM). T2DM is an important risk factor of intervertebral disc degeneration (IVDD). Although the relationship between type I diabetes and IVDD has been reported by many studies, few studies have reported the effects of T2DM on IVDD in db/db mice model. METHODS: Mice were separated into 3 groups: wild-type (WT), db/db, and IGF-1 groups (leptin receptor-deficient mice were treated with insulin-like growth factor-1 (IGF-1). To observe the effects of T2DM and glucose-lowering treatment on IVDD, IGF-1 injection was used. The IVD phenotype was detected by H&E and safranin O fast green staining among db/db, WT and IGF-1 mice. The levels of blood glucose and weight in mice were also recorded. The changes in the mass of the trabecular bone in the fifth lumbar vertebra were documented by micro-computed tomography (micro-CT). Tunnel assays were used to detect cell apoptosis in each group. RESULTS: The weight of the mice were 27.68 ± 1.6 g in WT group, which was less than 57.56 ± 4.8 g in db/db group, and 52.17 ± 3.7 g in IGF-1 injected group (P < 0.05). The blood glucose levels were also significantly higher in the db/db mice group. T2DM caused by leptin receptor knockout showed an association with significantly decreased vertebral bone mass and increased IVDD when compared to WT mice. The db/db mice induced by leptin deletion showed a higher percentage of MMP3 expression as well as cell apoptosis in IVDD mice than WT mice (P < 0.05), while IGF-1 treatment reversed this situation (P < 0.05). CONCLUSIONS: T2DM induced by leptin receptor knockout led to IVDD by increasing the levels of MMP3 and promoting cell apoptosis. IGF-1 treatment partially rescue the phenotype of IVDD induced by leptin receptor knockout.

Possible involvement of the oxLDL/LOX-1 system in the pathogenesis and progression of human intervertebral disc degeneration or herniation.

Epidemiological studies have concluded that hyperlipidemia and atherosclerosis were related to intervertebral disc degeneration (IVDD). The presence of oxidized low density lipoprotein (ox-LDL) and the expression of lectin-like oxidized low density lipoprotein receptor 1 (LOX-1) have not been explored in this tissue. In this study, we investigated the presence of ox-LDL and the expression of its receptor LOX-1 in non-degenerated, degenerated or herniated human intervertebral discs (IVDs). The expression of LOX-1 and matrix metalloproteinase 3 (MMP3) were studied after incubating nucleus pulposus cells (NPCs) with ox-LDL. The presence of ox-LDL and LOX-1 was positively related with the extent of IVDD in nucleus pulposus (NP), end-plate cartilage and outer annulus fibrous, but not with the extent of degeneration of inter annulus fibrous. Ox-LDL significantly reduced the viability of human NPCs in a dose and time-dependent manner, and increased the expression of MMP3 induced by LOX-1. Pretreatment with anti-human LOX-1 monoclonal antibody reversed these effects. Ox-LDL, principally mediated by LOX-1, enhanced MMP3 production in NPCs through the NF-κB signaling pathway. In conclusion, increased accumulation of ox-LDL and LOX-1 in IVDs indicates a specific role of the receptor-ligand interaction in degeneration or herniation of IVDs.

Significance of preoperative planning software for puncture and channel establishment in percutaneous endoscopic lumbar DISCECTOMY: A study of 40 cases.

BACKGROUND: Preoperative planning software has been widely used in many other minimally invasive surgeries, but there is a lack of information describing the clinical benefits of existing software applied in percutaneous endoscopic lumbar discectomy (PELD). This study aimed to compare the clinical efficacy of preoperative planning software in puncture and channel establishment of PELD with routine methods in treating lumbar disc herniation (LDH). MATERIAL AND METHODS: From June 2016 to October 2016, 40 patients who had single L4/5 or L5/S1 disc herniation were divided into two groups. Group A adopted planning software for preoperative puncture simulation while Group B took routine cases discussion for making puncture plans. The channel establishment time, operative time, fluoroscopic times and complications were compared between the two groups. The surgical efficacy was evaluated according to the Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) and modified Macnab's criteria. RESULTS: The mean channel establishment time was 25.1 ± 4.2 min and 34.6 ± 5.4 min in Group A and B, respectively (P < 0.05). The mean operative time was 80.8 ± 8.4 min and 92.1 ± 7.3 min in Group A and B, respectively (P < 0.05). The fluoroscopic times were 21.5 ± 5.2 in Group A and 29.3 ± 5.5 in Group B (P < 0.05). There were no significant differences in VAS and ODI scorings between the two groups either preoperatively or postoperatively (P > 0.05). The findings of modified Macnab's criteria at each follow-up also showed no significant differences (P > 0.05). CONCLUSION: The application of preoperative planning software in puncture and cannula insertion planning in PELD was easy and reliable, and could reduce the channel establishment time, operative time and fluoroscopic times of PELD significantly.

Percutaneous endoscopic lumbar discectomy for recurrent lumbar disc herniation.

The objective of this systematic review was to identify the effectiveness of percutaneous endoscopic lumbar discectomy (PELD) in the treatment of recurrent lumbar disc herniation (rLDH) and to present its indications and techniques. We conducted a comprehensive search in MEDLINE, EMBASE, PubMed, Web of Science and Cochrane databases, searching for relevant studies of managing rLDH with PELD up to July 2015. Only papers published in English were included. Two review authors independently selected the studies, extracted relevant data and assessed their methodological quality. The Cochrane Collaboration's Revman 5.3 software was used for data analyses among the controlled studies. At last, one randomized controlled trial (RCT), two non-randomized control studies and five observational studies including a total of 579 cases were selected for this system review. The methodological quality of these studies was low to modern. The mean overall improvement of leg pain (visual analogue scale) was 66.92% (50.6%-89.87%), back pain (visual analogue scale) 54.91% (29%-67.95%), Oswestry Disability Index 60.9% (40.7%-75%), global perceived effect (MacNab/other) 75.77% (60%-95%). The mean overall of complication rate was 4.89% (0%-9.76%), dural tear rate 0.1% (0%-4.9%), recurrence rate 6.3% (4%-10%), re-operation rate 3.66% (2.33%-4.8%). We conducted a meta-analysis among the control trials. Compared with Open discectomy (OD), PELD resulted in better outcomes in terms of operative time, blood loss, lower complication rates, but with no significance differences regarding hospital stay, second recurrence rate, Macnab criteria and pain reduction. In conclusion, according to the current evidence, PELD is an effective procedure for the treatment of rLDH in terms of reducing complication and shorting hospital course, comparing with OD. Therefore, we suggested that PELD was a feasible alternative to OD in the treatment of the rLDH in the condition of proper indication. High-quality RCTs with large sample sizes are needed to further confirm these results.