Association of modic changes and postoperative surgical site infection after posterior lumbar spinal fusion.

PURPOSE: Postoperative surgical site infection is one of the most serious complications following spine surgery. Previous studies have reported Modic changes (MC) represent a subclinical infection. This study aims to investigate the relation between Modic changes and surgical site infection after posterior lumbar fusion surgery. METHODS: We retrospectively reviewed the records of 424 patients who received posterior lumbar fusion. Preoperative clinical and radiological parameters were recorded. Primary outcome was the rate of postoperative surgical site infection. Covariates included age, body mass index (BMI), sex, hypertension, diabetes mellitus, chronic heart failure, Pfirrmann classification, fused levels, and operation duration. The presence of Modic changes was used as an exposition variable, and adjusted for other risk factors in multivariate analyses. RESULTS: Of the 424 patients, 30 (7%) developed an acute surgical site infection. Infection had no relation to age, sex, BMI, and comorbidities. There were 212 (50%) patients with MC, and 23 (10.8%) had a surgical site infection, compared to 212 (50%) patients without MC in which there were 7 (3.3%) surgical site infections. MC was associated with surgical site infection in univariate analysis (odds ratio [OR] = 3.56, 95% confidence interval [CI]: 1.49-8.50, p = 0.004) and multivariate logistic regression analysis (OR = 3.05, 95% CI: 1.26-7.37, p = 0.013). There was statistically significant between specific type (p = 0.035) and grade of MCs (p = 0.0187) and SSI. CONCLUSIONS: MCs may be a potential risk factor for SSI following posterior lumbar spinal intervertebral fusion. Type I and grade C MCs showed a higher infection rate compared with other MC types and grades.

[Comparison of Clinical Effects of Cortical Bone Trajectory Screws and Traditional Pedicle Screws in Posterior Lumbar Fusion]. / è °æ¤ŽåŽè·¯èžåˆæœ¯ä¸­çš®è´¨éª¨è½¨è¿¹èžºé’‰å’Œä¼ ç»Ÿæ¤Žå¼“æ ¹èžºé’‰çš„ä¸´åºŠæ•ˆæžœæ¯”è¾ƒ.

Objective: To compare the clinical effects of cortical bone trajectory screws and traditional pedicle screws in posterior lumbar fusion. Methods: A retrospective study was conducted to analyze lumbar degeneration patients who underwent surgical treatment at our hospital between January 2016 and January 2019. A total of 123 patients who met the inclusion criteria were enrolled. The subjects were divided into two groups according to their surgical procedures and the members of the two groups were matched by age, sex, and the number of fusion segments. There were 63 patients in the traditional pedicle screws (PS) group and 60 in the cortical bone trajectory screws (CBTS) group. The outcomes of the two groups were compared. The primary outcome measures were perioperative conditions, including operation duration, estimated intraoperative blood loss (EBL), and length-of-stay (LOS), visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, and interbody fusion rate. The secondary outcome measures were the time to postoperative ambulation and the incidence of complications. VAS scores and ODI scores were assessed before operation, 1 week, 1 month, 3 months, and 12 months after operation, and at the final follow-up. The interbody fusion rate was assessed in 1 year and 2 years after the operation and at the final follow-up. Results: The CBTS group showed a reduction in operation duration ([142.8±13.1] min vs. [174.7±15.4] min, P<0.001), LOS ([9.5±1.5] d vs. [12.0±2.0] d, P<0.001), and EBL ([194.2±38.3] mL vs. [377.5±33.1] mL, P<0.001) in comparison with the PS group. The VAS score for back pain in the CBTS group was lower than that in the PS group at 1 week and 1 month after operation and the ODI score in the CBTS group was lower than that in the PS group at 1 month after operation, with the differences being statistically significant (P<0.05). At each postoperative time point, the VAS score for leg pain and the interbody fusion rate did not show significant difference between the two groups. The VAS score for back and leg pain and the ODI score at each time point after operation in both the CBTS group and the PS group were significantly lower than those before operation (P<0.05). No significant difference was found in the time to postoperative ambulation or the overall complication incidence between the two groups. Conclusion: The CBTS technique could significantly shorten the operation duration and LOS, reduce EBL, and achieve the same effect as the PS technique does in terms of intervertebral fusion rate, pain relief, functional improvement, and complication incidence in patients undergoing posterior lumbar fusion.

Association between immediate postoperative hypoalbuminemia and surgical site infection after posterior lumbar fusion surgery.

PURPOSE: In this study, we intended to investigate the association between immediate postoperative hypoalbuminemia and surgical site infection (SSI), and determine a threshold value for postoperative hypoalbuminemia that can assist in risk stratification in patients after posterior lumbar fusion surgery. METHODS: From January 2017 to December 2021, 466 consecutive patients who underwent posterior lumbar fusion surgery were selected to analyze the relationship between immediate postoperative hypoalbuminemia and SSI. Multivariate logistic regression analysis was performed to identify the independent risk factors of SSI and postoperative hypoalbuminemia. Receiver Operating Characteristic (ROC) analysis was used to determine the optimal value for postoperative hypoalbuminemia, and subsequent grouping was based on the identified threshold. RESULTS: Of the total 466 patients, 25 patients (5.4%) developed SSI after surgery, and lower postoperative albumin (OR: 0.716, 95% CI: 0.611-0.840, p < 0.001) was independently associated with SSI. ROC analysis showed that the cutoff value of postoperative hypoalbuminemia was 32 g/L with a sensitivity of 0.760, specificity of 0.844, and a Youden index of 0.604. Postoperative SSI was more common in patients with postoperative hypoalbuminemia than in those without (21.6% vs. 1.6%, p < 0.001). Age, gender and operative duration were found to be independent predictors of postoperative hypoalbuminemia. CONCLUSIONS: This study showed that immediate postoperative hypoalbuminemia was an independent risk factor for the development of SSI in patients who underwent posterior lumbar fusion. Even in patients with a normal preoperative serum albumin level, there was an increased risk of SSI when the postoperative albumin within 24 h was < 32 g/L.

Posterior lumbar fusion surgery doesn't change sexual activities in patients with lumbar degenerative disease: an observational study.

BACKGROUND: There are few studies about sexual function in the patient with posterior lumbar spinal fusion for degenerative lumbar disease. The aim of this study is to investigate sexual activities in patients with lumbar degenerative disease before and after lumbar fusion surgery. METHODS: We recruited 35 patients who underwent lumbar spinal fusion at the age of 55 years or younger. They were 17 men and 18 women with a mean age of 47.4 years. After informed consent, the patients were asked to complete anonymous questionnaire concerning sexual desire, activity, and satisfaction before and after surgery. RESULTS: In the presick period, 69% of the patients had sexual desire, and 79% achieved satisfaction during sexual activity. Lumbar degenerative disease decreased sexual desire and frequency of sexual activity in 40%, and 74% respectively. Before surgery, satisfaction in sexual activities decreased in 53%, and 55% of the patients felt discomfort during sexual activity. Adjustment in sexual position was required in 44% of man and 54% of woman. After surgery, Sexual desire, frequency of sexual activity and satisfaction did not regain after surgery in 94%, 93% and 92%, respectively. Those who did not feel discomfort after surgery was significantly lower VAS in both low back pain and leg pain than the patients felt discomfort (low back pain; p = 0.024, leg pain; p = 0.046). CONCLUSION: This study demonstrated that lumbar degenerative diseases decreased sexual desire, frequency of sexual activity and satisfaction, and little of the patients regained their sexual activities after posterior lumbar fusion surgery in the middle-aged patients.

The effect of the cortical bone trajectory screw fixation and traditional pedicle screw fixation on surgical site wound infection in posterior lumbar fusion wound: A meta-analysis.

A meta-analysis investigation was performed to measure the influence of cortical bone trajectory screw fixation (CBTSF) and traditional pedicle screw fixation (TPSF) on surgical site wound infection (SSWI) in posterior lumbar fusion (PLF). A comprehensive literature inspection till February 2023 was applied and 1657 interrelated investigations were reviewed. The 13 chosen investigations enclosed 1195 individuals with PLF in the chosen investigations' starting point, 578 of them were using CBTSF, and 617 were using TPSF. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were utilised to compute the value of the effect of the CBTSF and TPSF on SSWI in PLF by the dichotomous approaches and a fixed or random model. No significant difference was found between individuals using CBTSF and TPSF in SSWI (OR, 0.68; 95% CI, 0.35-1.33, P = .26), superficial SSWI (OR, 0.62; 95% CI, 0.22-1.79, P = .38), and deep SSWI (OR, 0.30; 95% CI, 0.06-1.50, P = .14) in PLF. No significant difference was found between individuals using CBTSF and TPSF in SSWI, superficial SSWI, and deep SSWI in PLF. However, care must be exercised when dealing with its values because of the small sample sizes of several chosen investigations for this meta-analysis and the low number of selected investigations for a certain type of SSWI.

Risk factors for early reoperation in patients after posterior lumbar interbody fusion surgery. A propensity-matched cohort analysis.

BACKGROUND: Reoperation is usually associated with poor results and increased morbidity and hospital costs. However, the rates, causes, and risk factors for reoperation in patients undergoing lumbar spinal fusion surgery remain controversial. This study aimed to identify the risk factors for early reoperation after posterior lumbar interbody fusion surgery and to compare the clinical outcomes between patients who underwent reoperation and those who did not. METHODS: We investigated a multicenter medical record database of 1263 patients who underwent posterior lumbar interbody fusion surgery between 2012 and 2015. A total of 72 (5.7%) reoperations within two years after surgery were identified and were propensity-matched for age, sex, number of fusion segments, and surgeon's experience. RESULTS: We analyzed a total of 114 patients (57 who underwent reoperation (R group) and 57 who did not (C group)). The mean age was 62.6 ± 13.4 years, with 78 men and 36 women. The mean number of fused segments was 1.2 ± 0.5. Surgical site infection was the most common cause of reoperation. There were significant differences in the incidence of diabetes mellitus (p = 0.024), preoperative ambulation status (p = 0.046), and ASA grade (p < 0.001) between the C and R groups. The recovery rate of the Japanese Orthopaedic Association score was significantly lower in the R group compared to the C group (R: 50.5 ± 28.8%, C: 63.9 ± 33.7%, p = 0.024). There were significant differences in the bone fusion rate (R: 63.2%, C: 96.5%, p < 0.001) and incidence of screw loosening (R: 31.6%; C: 10.5%; p = 0.006). CONCLUSION: Diabetes mellitus, preoperative ambulation status, and ASA grade were significant risk factors for early reoperation following posterior lumbar interbody fusion surgery. The patients who underwent early reoperation had worse clinical outcomes than those who did not.

Lumbar spine fusion outcomes using a cellular bone allograft with lineage-committed bone-forming cells in 96 patients.

BACKGROUND: Instrumented posterior lumbar fusion (IPLF) with and without transforaminal interbody fusion (TLIF) is a common treatment for low back pain when conservative interventions have failed. Certain patient comorbidities and lifestyle risk factors, such as obesity and smoking, are known to negatively affect these procedures. An advanced cellular bone allograft (CBA) with viable osteogenic cells (V-CBA) has demonstrated high fusion rates, but the rates for patients with severe and/or multiple comorbidities remain understudied. The purpose of this study was to assess fusion outcomes in patients undergoing IPLF/TLIF using V-CBA with baseline comorbidities and lifestyle risk factors known to negatively affect bone fusion. METHODS: This was a retrospective study of de-identified data from consecutive patients at an academic medical center who underwent IPLF procedures with or without TLIF, and with V-CBA. Baseline patient and procedure characteristics were assessed. Radiological outcomes included fusion rates per the Lenke scale. Patient-reported clinical outcomes were evaluated via the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for back and leg pain. Operating room (OR) times and intraoperative blood loss rates were also assessed. RESULTS: Data from 96 patients were assessed with a total of 222 levels treated overall (mean: 2.3 levels) and a median follow-up time of 16 months (range: 6 to 45 months). Successful fusion (Lenke A or B) was reported for 88 of 96 patients (91.7%) overall, including in all IPLF-only patients. Of 22 patients with diabetes in the IPLF+TLIF group, fusion was reported in 20 patients (90.9%). In IPLF+TLIF patients currently using tobacco (n = 19), fusion was reported in 16 patients (84.3%), while in those with a history of tobacco use (n = 53), fusion was observed in 48 patients (90.6%). Successful fusion was reported in all 6 patients overall with previous pseudarthrosis at the same level. Mean postoperative ODI and VAS scores were significantly reduced versus preoperative ratings. CONCLUSION: The results of this study suggest that V-CBA consistently yields successful fusion and significant decreases in patient-reported ODI and VAS, despite patient comorbidities and lifestyle risk factors that are known to negatively affect such bony healing.

Lumbar spinal stenosis combined with obesity-induced idiopathic spinal epidural lipomatosis treated with posterior lumbar fusion: case report.

BACKGROUND: Spinal epidural lipomatosis is a rare cause of lumbar spinal stenosis. While conservative therapy is applicable for most of cases, surgical intervention is necessary for severe ones. This is the first time we apply this modified technique to this disease. CASE PRESENTATION: The case is a 53-year-old man. He is 175 cm tall and weighs 102 kg (body mass index 33.3 kg/cm2), presenting with low back pain and bilateral legs pain and numbness. Radiological examination showed severe lumbar spinal stenosis resulting from adipose hyperplasia, combined with hyperosteogeny and hypertrophy of ligaments, which are common etiological factors. Posterior decompression, internal fixation and a modified articular fusion technique was performed on this patient, and regular follow-up that up o 22 months showed outstanding clinical outcomes. CONCLUSIONS: A suitable style of posterior lumbar fusion should be considered to especially severe case with lumbar spinal stenosis and idiopathic spinal epidural lipomatosis.

Comparison of extreme lateral approach with posterior approach in the treatment of lumbar degenerative diseases: A meta-analysis of clinical and imaging findings.

OBJECTIVE: To compare clinical and imaging findings between extreme lateral lumbar interbody fusion (XLIF) and posterior fusion (PF) via meta-analysis for the treatment of lumbar degenerative diseases. METHODS: English papers reporting clinical and imaging findings for the treatment of lumbar degenerative diseases with XLIF and PF published electronically in the PubMed, Embase, Cochrane Library, and Web of Science databases from January 2006 to August 2019 were retrieved. Two authors independently extracted data and evaluated the quality of the included literature. Meta-analysis of outcome measures was performed using Stata 14 and RevMan 5.3 software. RESULTS: This meta-analysis included 744 patients from nine studies, two of which were prospective studies, while the others were retrospective studies. The quality of each study was determined to be high. The meta-analysis showed no significant differences in the operative time, length of hospital stay, clinical effectiveness, and improvement in postoperative global sagittal alignment between two approaches (P > 0.05). However, XLIF was significantly better than PF in reducing intraoperative blood loss and recovery of local sagittal alignment (P < 0.05). Moreover, the high incidence of postoperative complications were detected in XLIF group (P < 0.05). CONCLUSIONS: Both surgical approaches have equally promising clinical effectiveness for the treatment of lumbar degenerative diseases. Although XLIF can reduce intraoperative blood loss and obtain better postoperative local sagittal alignment than PF, the high incidence of postoperative complications should prompt us to consider why XLIF procedure is still being offered to our patients and how we can reduce these complications. In addition, any conclusions should be taken with caution because of the mix of prospective and retrospective studies, and the high heterogeneity and bias.

The incidence of stroke among selected patients undergoing elective posterior lumbar fusion: a retrospective cohort study.

BACKGROUND: Although stroke is a rare complication among spinal surgery patients, the recognition of this adverse event is critical given the aging population undergoing surgical procedures. The objective of this study was to estimate the incidence of stroke among selected adults undergoing elective posterior lumbar fusion (PLF) during various post-operative risk windows and among different subgroups. METHODS: A retrospective cohort study using a longitudinal electronic healthcare record (EHR) database was conducted from January 1, 2007 to June 30, 2018. Elective PLF, stroke, and select clinical characteristics were defined based on International Classification of Disease codes. Patients aged 18 to 85 years with ≥183 days of enrollment in the database prior to undergoing elective PLF were followed from the index date until the occurrence of stroke, death, loss to follow-up, or end of study period, whichever occurred first. The incidence of stroke was estimated in the following risk windows: index hospitalization, ≤ 30 days, ≤ 90 days, ≤ 180 days, and ≤ 365 days post-operation. RESULTS: A total of 43,063 patients were eligible for the study. The incidence of stroke following elective PLF was 0.29% (95% confidence interval [CI]: 0.25, 0.35%) during index hospitalization, 0.44% (95% CI: 0.38, 0.50%) ≤ 30 days, 0.59% (95% CI: 0.52, 0.67%) ≤ 90 days, 0.76% (95% CI: 0.68, 0.85%) ≤ 180 days, and 1.12% (95% CI: 1.03, 1.23%) ≤ 365 days post-operation. Stratified analyses revealed that older patients had a higher incidence of stroke. Additionally, black patients had higher stroke incidences. Post-operative stroke incidence was higher among patients with a history of type 2 diabetes than among patients without such history; similarly, stroke incidence was higher among patients with a history of stroke compared to patients without such history. CONCLUSIONS: The incidence of stroke following elective PLF using an EHR database in this study is slightly higher than that reported in the literature. Our results suggest that stroke risk modification prior to PLF may be important for patients who are older, black, type 2 diabetic, and/or have a history of stroke.

The impact of anesthesia and surgical provider characteristics on outcomes after spine surgery.

PURPOSE: Information regarding the impact of provider characteristics on perioperative outcomes in the spine surgery setting is limited. Existing studies primarily consider the impact of surgical provider volume. This analysis sought to identify the impact of anesthesiologist and surgeon volume and experience as well as anesthesia care team composition on adverse outcomes following anterior cervical discectomy and fusions (ACDF) and posterior lumbar fusions (PLF). METHODS: We identified 5900 patients who underwent ACDF or PLF procedures at a high-volume orthopedic institution from 2005 to 2014. Provider characteristics of interest were anesthesiologist and surgeon volume and experience along with anesthesia care team composition. Multivariable logistic regression models were used to evaluate the outcomes of any complication, cardiopulmonary complication, and prolonged length of stay (> 7 days). Intraclass correlation coefficients were calculated to determine how much variation in outcomes could be explained by provider characteristics. RESULTS: There were no significant relationships between provider characteristics and perioperative outcomes among ACDF patients. Within the PLF cohort, surgeon annual case volume > 25 was associated with decreased odds of prolonged length of stay, while anesthesia resident involvement was associated with increased odds of prolonged length of stay. Surgeon characteristics explained the greatest proportion of variation in outcomes while anesthesiologist characteristics explained the least. CONCLUSIONS: Anesthesia provider volume and experience did not significantly impact the odds of adverse outcome for ACDF and PLF patients. Higher surgeon volume was exclusively associated with decreased odds of prolonged length of stay following PLF. Further study is necessary to determine if these relationships persist in a less-specialized setting. These slides can be retrieved under Electronic Supplementary Material.

Efficacy and safety of tranexamic acid usage in patients undergoing posterior lumbar fusion: a meta-analysis.

BACKGROUND: The purpose of this meta-analysis is to evaluate the efficacy and safety of tranexamic acid (TXA) for patients with degenerative lumbar disc herniation, stenosis or instability undergoing posterior lumbar fusion (PLF) surgery. METHODS: We searched PubMed, Embase, and Cochrane Library until May 1, 2018. Two reviewers selected studies, assessed quality, extracted data, and evaluated the risk of bias independently. Weighted mean difference (WMD) and relative risk (RR) were calculated as the summary statistics for continuous data and dichotomous data, respectively. We chose fixed-effects or random-effects models based on I2 statistics. RevMan 5.0 and STATA 14.0 software were used for data analysis. RESULTS: Nine studies enrolling 713 patients for the study. The pooled outcomes demonstrated that TXA can decrease total blood loss (TBL) in patients underwent PLF surgery [WMD = -250.68, 95% CI (- 325.06, - 176.29), P<0.001], intraoperative blood loss (IBL) [WMD = -72.57, 95% CI (- 103.94, - 41.20), P<0.001], postoperative blood loss (PBL) [WMD = -127.57, 95% CI (- 149.39, - 105.75), P<0.001], and the loss of hemoglobin (Hb) in postoperative 24 h [WMD = -0.31, 95% CI (- 0.44, - 0.18), P<0.001]. However, there is no significant difference between two groups in transfusion rate [RR =0.34, 95% CI (0.09, 1.28), P = 0.11], and none thrombotic event was happened in the two groups. CONCLUSION: Our meta-analysis demonstrated that TXA can decrease the Hb loss, TBL, IBL, PBL, and without increasing the risk of thrombotic event in patients with degenerative lumbar disc herniation, stenosis or instability underwent PLF surgery. However, there was no significant difference in blood transfusion rates between the two groups.

Effect of lordosis on adjacent levels after lumbar interbody fusion, before and after removal of the spinal fixator: a finite element analysis.

BACKGROUND: Literature indicates that adjacent-segment diseases after posterior lumbar interbody fusion with pedicle screw fixation accelerate degenerative changes at unfused adjacent segments due to the increased motion and intervertebral stress. Sagittal alignment of the spine is an important consideration as achieving proper lordosis could improve the outcome of spinal fusion and avoid the risk of adjacent segment diseases. Therefore, restoration of adequate lumbar lordosis is considered as a major factor in the long-term success of lumbar fusion. This study hypothesized that the removal of internal fixation devices in segments that have already fused together could reduce stress at the disc at adjacent segments, particularly in patients with inadequate lordosis. The purpose of this study was to analyze the biomechanical characteristics of a single fusion model (posterior lumbar interbody fusion with internal fixation) with different lordosis angles before and after removal of the internal fixation device. METHODS: Five finite element models were constructed for analysis; 1) Intact lumbar spine without any implants (INT), 2) Lumbar spine implanted with a spinal fixator and lordotic intervertebral cage at L4-L5 (FUS-f-5c), 3) Lumbar spine after removal of the spinal fixator (FUS-5c), 4) Lumbar spine implanted with a spinal fixator and non-lordotic intervertebral cage at L4-L5 (FUS-f-0c), and 5) Lumbar spine after removal of the spinal fixator from the FUS-f-0c model (FUS-0c). RESULTS: The ROM of adjacent segments in the FUS-f-0c model was found to be greater than in the FUS-f-5c model. After removing the fixator, the adjacent segments in the FUS-5c and FUS-0c models had a ROM that was similar to the intact spine under all loading conditions. Removing the fixator also reduced the contact forces on adjacent facet joints and reduced the peak stresses on the discs at adjacent levels. The greatest increase in stress on the discs was found in the FUS-f-0c model (at both L2/L3 and L3/L4), with intervertebral stress at L3/L4 increasing by 83% when placed in flexion. CONCLUSIONS: This study demonstrated how removing the spinal fixation construct after bone fusion could reduce intradiscal pressure and facet contact forces at adjacent segments, while retaining a suitable level of lumbar lordosis.

Clinical Research of Combined Intravenous Administration and Topical Application of Tranexamic Acid to a Surgical Wound During Posterior Lumbar Fusion.

BACKGROUND: The safety and effectiveness of combined intravenous and topical administration of tranexamic acid (TXA) on the reduction of blood loss in patients undergoing posterior lumbar fusion are not yet clear. The study aimed to investigate the safety and effectiveness of the combined intravenous and topical administration of TXA on the reduction of blood loss in patients undergoing posterior lumbar fusion. METHOD: One hundred and eighteen patients who underwent double-segment posterior lumbar decompression and fusion from February 2014 to May 2016 in our hospital were retrospectively reviewed. Patients were divided into two groups, the experimental group and the control group. Preoperative demographics, operative parameters, and adverse effect were recorded and compared. RESULTS: Intraoperative blood loss, postoperative 24-hour drainage volume, and blood transfusion ratio and volume were significantly lower in the experimental group than in the control group (P < .01); on postoperative 24 hours and 48 hours, hemoglobin and hematocrit levels were significantly higher in the experimental group than in the control group (P < .01). Prothrombin time and fibrinogen content were not significantly different between the 2 groups. The postoperative length of hospital stay was shorter in the experimental group than in the control group (P < .01). No postoperative thrombotic events were reported in either group. CONCLUSIONS: Combined intravenous and topical administration of TXA seems to be effective and safe in reducing allogenic blood transfusion and blood loss in double-segment posterior lumbar decompression and fusion surgery.

Predictors of haematocrit in lumbar fusion for lumbar disc herniation: a surgical assessment.

BACKGROUND: Low haematocrit (Hct) is associated with a higher rate of post-operative complications, increased mortality, and additional medical costs following cardiac surgery. Predictors of post-operative Hct in lumbar fusion are unclear and may be beneficial in avoiding adverse surgical outcomes. METHODS: A total of 704 lumbar disc herniation patients (385 males, 319 females) who underwent primary lumbar fusion surgery were reviewed in this retrospective study. RESULTS: In the 687 patients who met the selection criteria, the pre-operative Hct was 41.23 ± 4.57%, the post-operative Hct was 32.61 ± 4.52%, the peri-operative Hct decline was 8.62 ± 4.07%, the estimated intra-operative blood loss was 586.76 ± 346.62 mL, and the post-operative drainage was 489.33 ± 274.32 mL. Pre-operative Hct, estimated blood volume, estimated intra-operative blood loss, post-operative drainage, allogeneic blood transfusion, and age showed significant correlations with post-operative Hct, and all factors were involved in the final multiple regression model. Patients who received intensive care had lower post-operative Hct values, and the length of post-operative hospital stay was negatively correlated with post-operative Hct. CONCLUSIONS: Dangerously low post-operative Hct is related to the length of ICU stay and post-operative hospital stay. Age, pre-operative Hct, intra-operative blood loss, post-operative drainage, and units of allogeneic blood transfusion are significant predictors of post-operative Hct and Hct decline. Hct variations during the operation make the calculation of total blood loss difficult.

Spinal metallosis: a systematic review.

PURPOSE: To document a rarely reported complication associated with spinal instrumentation and to evaluate the current literature on spinal metallosis and spinal metalloma. METHODS: A local case report is presented. EBSCOhost, PubMed and ScienceDirect databases were used to conduct a systematic review for articles describing spinal metallosis and spinal metalloma. RESULTS: A total of 836 articles were identified using the terms "metalloma" or "metallosis". Exclusion of arthroplasty-related abstracts retrieved 46 articles of which 3 full text articles presenting spinal metalloma as a causative pathological finding responsible for neurological signs and symptoms in patients with previous spinal fusion instrumentation were reviewed. Our case is the first described with titanium-composed posterior instrumentation and fifth reported, demonstrating the phenomena of neurological symptoms and signs attributed directly to neural tissue compression by spinal metalloma after spinal instrumentation. CONCLUSION: Spinal metallosis can present weeks to years after spinal instrumentation surgery and is a potential cause of neural compression. This process appears to be independent of the instrument composition as metallosis has now been demonstrated in both titanium and stainless steel constructs.

Trends analysis of rhBMP utilization in single-level posterior lumbar fusion (PLF) in the United States.

PURPOSE: A retrospective database review was carried out to evaluate the trends and demographics of rhBMP utilization in single-level posterior lumbar fusion (PLF) in the United States. METHODS: Patients who underwent single-level PLF from 2005 to 2011 were identified by searching ICD-9 diagnosis and procedure codes in the PearlDiver Patient Records Database (PearlDiver Technologies, Fort Wayne, IN, USA), a national database of orthopaedic insurance records. The year of procedure, age, gender, and region of the United States were recorded for each patient. Results were reported for each variable as the incidence of procedures identified per 100,000 patients searched in the database. RESULTS: Totally 5158 patients had single-level PLF in this study. The average rate of single-level PLF with rhBMP utilization maintained at a relatively stable level (19.1-23.5%) from 2005 to 2009, but sharply decreased to 6.8% in 2010 and 6.9% in 2011. The overall incidence of single-level PLF without rhBMP (1.37 cases per 100,000 patients) was more than five times of the incidence of single-level PLF with rhBMP (0.27 cases per 100,000 patients) (P < 0.01). The average rate of single-level PLF with rhBMP utilization is highest in Midwest (18.7%), followed by West (18.4%), South (16.4%) and Northeast (11.5%). The highest incidence of single-level PLF with rhBMP was observed in the group aged 70-74 years with an incidence of 0.33 per 100,000 patients. CONCLUSIONS: The incidence of rhBMP utilization in single-level PLF increased from 2006 to 2009, but dropped to a low level in 2010 and 2011. The Northeast region had the lowest incidence of rhBMP utilization. The group aged 70-74 years trended to have the higher incidence of single-level PLF with rhBMP utilization.

[ALIF and PLIF interposition in low-grade isthmic spondylolisthesis L5/S1 : Longterm-Comparison of interbody fusion techniques (ALIF - PLIF)]. / ALIF- und PLIF-Interposition bei low-grade isthmischen Spondylolisthesen L5/S1 : Langzeitvergleich der interkorporellen Fusionstechnik (ALIF - PLIF).

INTRODUCTION: For the treatment of isthmic spondylolisthesis two alternative interbody fusion techniques are available, the dorsoventral interposition in ALIF technique and the dorsal access interposition in PLIF technique. Due to the complications of anterior lumbar surgery and in order to avoid a second operation, the dorsoventral fusion technique is becoming uncommon and mainly a pure dorsal supply is performed. The aim of the study was to compare the clinical long-term results of both treatment techniques. MATERIALS AND METHODS: 138 patients were treated surgically between 2003 and 2012 in symptomatic isthmic spondylolysis in L5/S1 with a Meyerding degree of I-III. 72 patients were evaluated finally (ALIF n = 25 and PLIF n = 47). The average follow-up period was 7.9 years for the ALIF group and 5.6 years for the PLIF group. In both groups the average drug consumption, duration of recovery, resumption of work and resumption of sport activities was recorded. RESULTS: The results showed an extended time of surgery and a prolonged hospitalization of 5.4 days for the ALIF group. The ODI had a greater improvement in the PLIF group but this difference was not significant. The VAS was reduced in both groups. 36.8 % of the ALIF group and 44.7 % of the PLIF group reported a reduced pain medication postoperatively. The average recovery was 16 weeks for both groups. 29 % of PLIF and 9 % of ALIF patients had no pain relief. ALIF patients were able to get back to work after 149 days and the PLIF patients after 178 days. 31 % of the PLIF group and 13 % of the ALIF group were not able to return back to work. Revisions of fusion and the rate of wound revisions were increased in the PLIF group, adjacent segment diseases occurred more frequently in the ALIF group. CONCLUSION: Both treatment and fusion techniques (ALIF/PLIF) were able to achieve a significant pain relief and reduced consumption of pain medication postoperatively. The recovery period was similar in both groups, but there were differences regarding the date of return to work, hospitalization, duration of surgery and ODI score. Neither of the two methods could show a definite advantage.

Single-use instrumentation in posterior lumbar fusion could decrease incidence of surgical site infection: a prospective bi-centric study.

PURPOSE: Single-use surgical instruments were recently introduced to improve OR efficiency and reduce infection risks. This study aimed to investigate clinical results 1 year after instrumented lumbar fusion, with the aid of single-use surgical instruments, with particular attention to surgical site infection and Oswestry Disability Index (ODI). METHOD: This prospective bi-centric study included 21 men and 28 women, aged 61.6 ± 12.8 years, that underwent short instrumented lumbar fusion for degenerative disc disease, canal stenosis, or degenerative spondylolisthesis. All patients underwent posterior or transforaminal lumbar interbody fusion, using the SteriSpine™ PS Pedicle Screw System, available in multiple traceable sterile kits. RESULTS: Instrumented fusion was performed at one level in 31, two levels in 11, three levels in 5, and four levels in 2 patients. The mean follow-up was 16.4 ± 2.1 months, during which the ODI improved by 20 or more points in 28 patients (57 %), improved by less than 20 points in 17 patients (35 %), and remained unchanged or worsened in 4 patients (8 %). Only one infection (2 %) was observed in a 60-year-old man with previous spine surgery and two additional risk factors (diabetes mellitus and BMI 38). Compared to an older series, using reusable instrumentation, performed by the same team for the same indications, the clinical outcomes were similar but the infection rate was 6 %. DISCUSSION: Single-use instrumentation could reduce the incidence of surgical site infections following lumbar fusion to acceptable levels as in hip and knee arthroplasties. The preservation of screws and rods in sterile packs until ready for insertion reduces their exposure to air-borne bacteria in the OR and eliminates their contamination through repetitive hospital sterilization. The short operation time and minimal blood loss achieved could also contribute to the reduction in infection risks. LEVEL OF EVIDENCE: Level II, prospective randomized bi-centric study.

Dynamic stabilization: a nidus for infection?

INTRODUCTION: Dynamic stabilization offers an adjunct to fusion with motion preservation. In comparison, standard instrumented fusion (if) consists of titanium screws and rods/plates, which do not allow for motion at the level of the fusion. The reported infection rate following a standard if ranges from 0.2% to 7%. METHODS: a retrospective chart review of 142 patients who underwent posterior lumbar stabilization procedures was conducted. Ten patients received dynamic stabilization and 132 patients had a standard if. Rates of infection, requiring hardware removal, were compared between the aforementioned groups. RESULTS: Of the 132 patients undergoing posterior if, three developed a deep wound infection requiring removal of hardware (2.3%). Of the 10 patients undergoing dynamic stabilization, three developed a deep wound infection (30%) with 2 requiring removal of hardware (20%), secondary to persistent deep wound infection or osteomyelitis at the pedicle screw sites. There was a significantly increased risk of deep wound infection (p < 0.0001) with the use of dynamic stabilization compared to standard if. CONCLUSIONS: Our series demonstrates that the infection rate in patients undergoing dynamic stabilization is higher than the infection rate for instrumented fusion without a significant difference in comorbidity scores. We postulate that the polycarbonate urethane spacer acts as a medium for bacteria, whereas the titanium screws and rods are smooth, solid, and inert, resulting in a lower risk of infection.