Surgical outcomes of infectious spondylitis after vertebroplasty, and comparisons between pyogenic and tuberculosis.

BACKGROUND: Infection after vertebroplasty (VP) is a rare but serious complication. Previous literatures showed most pathogens for infection after VP were bacteria; tuberculosis (TB) induced infection after VP was extremely rare. We reported our treatment experiences of cases with infectious spondylitis after VP, and compared the differences between developed pyogenic and TB spondylitis. METHODS: From January 2001 to December 2015, 5749 patients had undergone VP at our department were reviewed retrospectively. The causative organisms were obtained from tissue culture of revision surgery. Parameters including type of surgery, the interval between VP and revision surgery, neurologic status, and visual analog scale (VAS) of back pain were recorded. Laboratory data at the time of VP and revision surgery were collected. Charlson comorbidity index (CCI), preoperative bacteremia, urinary tract infection (UTI), pulmonary TB history were also analyzed. RESULTS: Eighteen patients were confirmed with developed infectious spondylitis after VP (0.32%, 18/5749). Two were male and 16 were female. The median age at VP was 73.4 years. Nine patients were TB and the other nine patients were pyogenic. The interval between VP and revision surgery ranged from 7 to 1140 days (mean 123.2 days). The most common type of revision surgery was anterior combined with posterior surgery. Seven patients developed neurologic deficit before revision surgery. Three patients died within 6 months after revision surgery, with a mortality of 16.7%. Finally, VAS of back pain was improved from 7.4 to 3.1. Seven patients could walk normally, the other 8 patients had some degree of disability. Both pyogenic and TB group had similar age, sex, and CCI distribution. The interval between VP and revision surgery was shorter in the patients with pyogenic organisms (75.9 vs 170.6 days). At revision surgery, WBC and CRP were prominently elevated in the pyogenic group. Five in the pyogenic group had UTI and bacteremia; five in TB group had a history of lung TB. CONCLUSIONS: Infection spondylitis after VP required major surgery for salvage with a relevant part of residual disability. Before VP, any bacteremia/UTI or history of pulmonary TB should be reviewed rigorously; any elevation of infection parameters should be scrutinized strictly.

Surgical outcomes after instrumented lumbar surgery in patients of eighty years of age and older.

BACKGROUND: In Taiwan, the life expectancy of an 80-year-old man is 88.4 years and the life expectancy of an 80-year-old woman is 89.8 years. Some of these people will develop symptomatic degenerative lumbar diseases that interfere with an active lifestyle. These older surgical candidates usually ask the surgeon whether it would be safe to undergo surgery. However, there is no literature assessing the outcomes of laminectomy, fusion and posterior fixation for degenerative lumbar diseases in patients older than 80 years. The purpose of this study was to report the surgical outcomes of patients 80 years of age and older who underwent spinal decompression and instrumented lumbar arthrodesis for degeneration lumbar diseases. METHODS: We retrospectively reviewed patients with degenerative lumbar diseases and spinal stenosis who underwent surgery between January 2010 and December 2012. Inclusion criteria were age greater than or equal to 80 years, decompression with instrumented lumbar arthrodesis, and at least 2 years of follow-up. Totally 89 patients were studies. Clinical outcomes were evaluated according to the Oswestry Disability Index (ODI) and visual analogue scale (VAS) of leg and back pain. Plain radiographs (lateral, anteroposterior, and flexion-extension) were used to assess the status of fusion and implant-related complications. Every complication during admission and any implant-related or failed-back syndrome requiring a second surgery was documented. T test and Fisher's exact test were used for statistical analysis. RESULTS: Five patients were lost to follow-up, and another 12 died during the follow-up period. One patient died due to cerebral stroke just 2 days after surgery, and the other 11 patients passed away 3 months to 4 years postoperatively. In all, 72 patients had an adequate follow-up: 44 were female and 28 were male. The average age at surgery was 82.5 ± 2.6 years (80 to 93); 63 patients underwent their first lumbar surgery, and nine patients received a second surgery. Patients underwent arthrodesis surgeries were from a single-level to a 7-level. Four patients developed complications (5.6 %, 4/72). At the final follow-up, the average ODI score was lower than the preoperative score (30.0 vs. 61.8) (p < 0.001). The average VAS score also showed improvement (leg: p < 0.001; back: p < 0.001). Forty-three patients were classified as "satisfied", and 29 were "dissatisfied". Longer operation time (p = 0.014) and development of complications (p = 0.049) were related to poor clinical results. Radiographic follow-up showed that 53 patients had solid union, ten had a probable union, and nine had pseudarthrosis. More surgical segments led to a greater chance of pseudarthrosis (2.0 ± 0.9 vs 3.0 ± 1.8, p = 0.003). CONCLUSION: Longer instrumented segments and development of complications contributed to worse clinical and radiographic outcomes. With proper patient selection, posterior decompression with instrumented fusion can be safe and effective for patients 80 years of age and older with degenerative lumbar conditions.

Effects of low-intensity pulsed ultrasound on spinal pseudarthrosis created by nicotine administration: a model of lumbar posterolateral pseudarthrosis in rabbits.

OBJECTIVES: Low-intensity pulsed ultrasound (US) can enhance spinal fusion and fracture healing; however, its effect on spinal pseudarthrosis has not been reported in the literature. We hypothesized that low-intensity pulsed US could overcome spinal pseudarthrosis created by nicotine administration. METHODS: Thirty-two rabbits underwent posterolateral fusion with an iliac bone graft and nicotine administration. At 5 weeks, the spines were examined by computed tomography (CT) to determine the presence of pseudarthrosis. All rabbits with pseudarthrosis were randomly divided into groups A, B, C, and D according to treatment: no second graft, iliac autograft only, low-intensity pulsed US only, and iliac autograft and low-intensity pulsed US, respectively. At 10 weeks, the rabbits were euthanized, and the specimens were assessed with radiography, CT, manual palpation, and histologic analysis. RESULTS: One rabbit was lost because of severe infection. Twenty-seven (87%) had pseudarthrosis on CT at 5 weeks. On manual palpation at 10 weeks, the fusion rates were 0%, 29%, 0%, and 57% in groups A, B, C, and D, respectively. Group D had highest radiographic scores (mean ± SD, 2.87 ± 0.92), and the difference was statistically significant compared to the other groups (P < .001). Computed tomography confirmed that group D had the most fused segments at 10 weeks. Histologic specimens from group D also showed the most mature bone formation inside the fusion mass. CONCLUSIONS: Low-intensity pulsed US can enhance spinal fusion but cannot overcome spinal pseudarthrosis created by nicotine administration. Stopping nicotine consumption or administering a more powerful bone substitute might be an alternative method for overcoming spinal pseudarthrosis.

The effects of anterior vacuum disc on surgical outcomes of degenerative versus spondylolytic spondylolisthesis: at a minimum two-year follow-up.

BACKGROUND: The vacuum phenomenon within the intervertebral disc usually represents disc degeneration. There are no reports in the English literature that focus on the effect of an anterior vacuum disc on surgical outcome of same-segment spondylolisthesis. METHODS: Patients with degenerative spondylolisthesis (DS) or isthmic spondylolisthesis (IS) who underwent a spinal surgery between January 2005 and December 2006 were reviewed. Patients who met certain criteria, including (1) only mono-segment spondylolisthesis, (2) gas air within the disc space of the spondylolisthesis segment on preoperative radiographs, (3) having received posterior decompression, posterior pedicle screw fixation, and posterolateral fusion, and (4) at least 12 months of follow-up radiographs available to define the posterolateral fusion rate, were enrolled into the study. Four radiographic parameters (disc height, translation, intradiscal angle, segmental angle) were assessed. Two-year postoperative radiographs were used to determine whether the posterolateral segment was fused or not. Clinical outcome and complications during the follow-up period were documented. RESULTS: Incidence of the disc vacuum phenomenon was significantly higher in the IS group than in the DS group (p < 0.001). The IS group had more listhesis and a narrower disc height on preoperative static radiographs; however, the DS group had a more prominent angle and listhesis change in preoperative dynamic variables. The posterolateral fusion rate was significantly higher in the IS group (p = 0.019). The preoperative Oswestry Disability Index (ODI) score, the final ODI, and the ODI difference were similar between groups. More excellent and good results were seen in the IS group. Besides, better final ODI and results were seen in the bilateral fusion group than in the nonfusion group. CONCLUSION: The disc vacuum phenomenon is not equal to anterior instability absolutely. Determination of stability or instability in a vacuum disc should be considered by a combination of dynamic radiographs. In the present study, vacuum discs in the DS group showed more instability and a higher posterolateral pseudoarthrosis rate.

Surgical outcomes of degenerative lumbar spondylolisthesis with anterior vacuum disc: can the intervertebral cage overcome intradiscal vacuum phenomenon and enhance posterolateral fusion?

BACKGROUND: The vacuum phenomenon within an intervertebral disc is not an uncommon radiographic finding in the elderly. However, no reports in the English literature have focused on the effect of an anterior vacuum disc in relation to surgical outcome of same-segment spondylolisthesis. We hypothesized that instrumented posterolateral fusion is not adequate in this situation and that additional interbody fusion with cages would provide better radiographic and clinical outcomes. METHODS: The medical records of 72 patients who underwent instrumented fusion for one-segment degenerative lumbar spondylolisthesis with a vacuum disc were reviewed. Thirty-three patients were placed in the noncage group and 39 in the cage group based on whether or not augmentation with an intervertebral cage was carried out. Radiographic parameters (disc height, translation, intradiscal angle, segmental angle, and fusion) on preoperative, postoperative, and final radiographs were compared between groups. The Oswestry Disability Index (ODI) and Brosky criteria were used to evaluate clinical outcomes. RESULTS: Blood loss and operation time were greater in the cage group but without a significant difference (p = 0.271, p = 0.108, respectively). Preoperative radiographic data were similar between groups, but the cage group had more intradiscal lordosis, less translation, a higher disc height after surgery, and maintained these advantages at the final follow-up. In addition, the posterolateral fusion rate was significantly higher in the cage group (92.3% vs. 56.1%, p < 0.001), and they obtained more ODI improvement (30.62 vs. 26.39, p = 0.369) and a higher final satisfaction rate (79.5% vs. 57.6%, p = 0.044). There was no decrease in the incidence of developed adjacent segmental disease in the noncage group. CONCLUSIONS: The vacuum sign at the spondylolisthesis segment should be regarded as another sign of instability. We suggest that instrumented posterolateral fusion simultaneous with intervertebral fusion with a cage can overcome this situation.

Surgery for metastatic epidural spinal cord compression in thoracic spine, anterior or posterior approach?

BACKGROUND: The most commonly encountered tumour of the spine is metastasis, and thoracic spine is the most commonly metastatic spine. Controversy exists regarding the optimal surgical approach for this kind of patient. The author conducted a study to assess the differences between anterior thoracotomy and a posterior approach in patients with malignant epidural cord compression in the thoracic spine. METHODS: Between January 2004 and December 2017, 97 patients with metastatic thoracic lesion were stratified into two groups by approach method to the lesion site: Group A - mean anterior thoracotomy, decompression and fixation; and Group P - represented posterior decompression and fixation. Survival time, neurologic status, each complication by surgery or in hospital, and days in intensive care unit(ICU) were compared. RESULTS: Twenty-five patients were grouped in Group A, and 72 patients belonged to Group P. Lung cancer was the most common primary cancer in both groups. Operation time (213.0 vs. 199.2 min, p = 0.380) and blood loss (912.5 vs. 834.4 ml, p = 0.571) were not statistically significantly different between the two groups. Six patients in Group A (24%) and 6 in Group P (8.3%) developed complications (p = 0.040). Patients in Group A required more days of care in ICUs (2.36 vs. 0.19 days, p < 0.001). The longer survival was seen in Group P (15.4 vs. 11.2 months) but with no significant difference. CONCLUSION: A lower surgical complication rate and fewer days of care in ICU were seen in Group P. The authors would prefer a posterior approach for those with thoracic metastatic tumour.

High viscosity bone cement vertebroplasty versus low viscosity bone cement vertebroplasty in the treatment of mid-high thoracic vertebral compression fractures.

BACKGROUND CONTEXT: As science and technology have advanced, novel bone cements with numerous formulated ingredients have greatly evolved and been commercialized for vertebroplasty. Recently, viscosity has been a focus to achieve better clinical outcomes and fewer complications. Meanwhile, the experience in the treatment of mid (T7-9) to high (T4-6) thoracic vertebral compression fractures is limited. PURPOSE: The objective of this study was to identify the different outcomes between high-viscosity bone cement (HVBC) and low-viscosity bone cement (LVBC) used to repair mid (T7-9)- and high (T4-6)- thoracic vertebral compression fractures. STUDY DESIGN/SETTING: This study was a single-center, retrospective cohort study PATIENT SAMPLE: A consecutive series of 107 patients with a total of 144 vertebrae was included. OUTCOME MEASURES: The anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), local kyphotic angle (KA), Cobb angle (CA), and other associated parameters were evaluated radiologically at several time points-preoperative, surgery day 0, postoperative day 1, and 6-month follow-up. Pain evaluation was assessed by using a visual analog scale (VAS) before and 6 months after the procedure. METHODS: The patients were divided into two groups according to the viscosity of the bone cement used, and plain film and magnetic resonance imaging (MRI) of the vertebrae were used to calculate parameters. The patient characteristics; bone cement brand; changes in AVH, MVH, PVH, KA, CA, and VAS; and complications of each patient were recorded and then analyzed. RESULTS: Both groups showed increased vertebral body height, corrected KA, and CA after vertebroplasty. There were no significant differences between the HVBC and LVBC groups (ΔAVH: 2.19±2.60 vs. 2.48±3.09, p=.555; ΔMVH: 1.25±3.15 vs. 1.89±2.58, p=.192; ΔKA: -5.46±4.58 vs -5.37±4.47, p=.908; and ΔCA: -4.22±4.23 vs. -4.56±5.17, p=.679). There were significant preoperative to postoperative and preoperative to follow-up changes in AVH (HVBC, p=.012 and .046, respectively; LVBC, p=.001 and .015, respectively); a significant preoperative to postoperative change in MVH (HVBC, p=.045; LVBC, p=.001); and significant preoperative to postoperative and preoperative to follow-up changes in KA and CA (KA: HVBC, p=0.000 and .003, respectively; LVBC, p=.000 and .000, respectively; CA: HVBC, p=.017 and .047, respectively; LVBC, p=.006 and .034, respectively). The volume of cement injected was significantly higher with HVBC (3.66±1.36 vs. 3.11±1.53, p=.024), and the use of HVBC was associated fewer cases with cement leakage (26 vs. 45, p=.002). Furthermore, there was no difference between the groups in the incidence of adjacent fracture. Both groups showed an improved VAS score at follow-up, with statistically greater improvement in the HVBC group (2.40±1.53 vs. 3.07±1.69, p=.014). Moreover, significantly fewer patients with a VAS score ≥ 3 were found in the HVBC group (22 vs. 39, p=.004) CONCLUSIONS: HVBC and LVBC are safe and effective to treat mid-to-high level thoracic vertebral compression fractures. Compared with LVBC, HVBC shows less cement leakage, a greater injection volume, and better postoperative pain relief.

Low-intensity pulsed ultrasound enhances healing of laminectomy chip bone grafts on spinal fusion: a model of posterolateral intertransverse fusion in rabbits.

BACKGROUND: Laminectomy-derived chip bone graft was usually used in spinal fusion; however, the result of this kind of local bone used in lumbar posterolateral fusion is uncertain. This study tested the hypotheses that low-intensity pulsed ultrasound (LIPU) can accelerate the healing process of laminectomy bone chips in a spinal fusion and enhance the union rate. METHODS: Forty-eight rabbits were randomly divided into three groups for the spinal unilateral uninstrumented posterolateral fusion of L5-L6: autologous iliac bone graft (AIBG), laminectomy chip bone graft (LCBG), LCBG plus LIPU (LCBG + LIPU). Each group was subdivided into 6-week and 12-week subgroups. All rabbits were subjected to radiographic examination and manual testing. All successful spinal fusion specimens received biomechanical testing and a histologic examination. RESULTS: The LCBG + LIPU group had the highest successful fusion rate at 6-week and 12-week examination (75% and 100%, respectively). At 6 weeks, the average maximum toque at failure values of the fusion masses for the LCBG + LIPU group was significantly higher than that for the LCBG group (p = 0.034). The average maximum torque of the 12-week LCBG + LIPU group was significantly higher than those of the 12-week AIBG and 12-week LCBG groups (p = 0.040 and p = 0.026, respectively). CONCLUSIONS: This study suggested that LIPU can enhance bone healing. With augmentation by LIPU, laminectomy chip bone used in lumbar posterolateral fusion can achieve a similar fusion rate and stronger fusion mass than those of an AIBG.

Tuberculous spondylitis after percutaneous vertebroplasty: A case series of 9 cases.

BACKGROUND: Percutaneous vertebroplasty has become the treatment of choice for compression fractures. Although the incidence is low, infection after vertebroplasty is a serious complication. The pathogens most often responsible for infection are bacteria. Meanwhile, mycobacterium tuberculosis-induced infection is extremely rare. In this study, we reported our treatment experience with 9 cases of tuberculous spondylitis after vertebroplasty. METHODS: Between January 2001 and December 2015, 5749 patients underwent vertebroplasty or kyphoplasty in our department. Nine cases developed tuberculous spondylitis after vertebroplasty (0.16%). Data on clinical history, laboratory examinations, image, treatment and outcomes were examined. RESULTS: One male and 8 female patients with a mean age of 75.1 years developed tuberculous spondylitis after vertebroplasty. 5 patients had a history of pulmonary tuberculosis (TB). Revision surgeries were performed from 5 days to 1124 days after vertebroplasty. Seven patients underwent anterior debridement and fusion with or without posterior instrumentation, and 2 cases received posterior decompression and instrumentation only. After operation, the diagnosis of tuberculous spondylitis was confirmed by TB polymerase chain reaction (TB-PCR) or mycobacteria culture. Mean follow-up period after revision surgery was 36.8 months. At the end of follow-up, 1 patient with paraplegia had passed away, 2 needed a wheel chair, 4 required a walker and 2 were able to walk unassisted. CONCLUSIONS: Vertebroplasty is a minimally invasive procedure but still retains some possibility of complications, including TB infection. Patients with a history of pulmonary TB or any elevation of infection parameters should be reviewed carefully to avoid infective complications.

Minimally invasive percutaneous endoscopic discectomy and drainage for infectious spondylodiscitis.

The primary goals for treating infectious spondylodiscitis are to make an accurate diagnosis, isolate the causative organism, and prescribe effective antibiotic therapy based on the culture data. A positive culture of the responsible organism is not required for diagnosis, although it is extremely important for successful treatment and prevention of further morbidity. Surgical intervention is usually reserved for cases that are unresponsive to antibiotic therapy and for patients who have developed progressive spinal deformity or instability, epidural abscesses, or neurological impairment. However, the incidence of perioperative morbidity is particularly increased in elderly patients or in those with poor general condition. With improved endoscopic instruments and techniques, our clinical experiences demonstrate that spinal infections can be successfully treated by minimally invasive percutaneous endoscopic debridement. Direct endoscopic observation and collection of sufficient quantities of samples for microbiological examinations from the infected region are usually possible. This article summarizes the diagnostic and therapeutic values of percutaneous endoscopic discectomy and drainage (PEDD) used to treat patients with spondylodiscitis. Our clinical evidence-based survey suggests that PEDD can provide adequate retrieval of specimens and has high diagnostic efficacy, thereby enabling prompt and sensitive antibiotic therapy to the offending pathogens. We propose that PEDD is an effective alternative for treating infectious spondylodiscitis and should be considered prior to extensive anterior surgery in selected cases. This method is particularly suitable for patients with early-stage spinal infection or serious medical conditions.

Chemical and physical properties of bone cement for vertebroplasty.

Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA) polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

Complications associated with instrumented lumbar surgery in patients with liver cirrhosis: a matched cohort analysis.

BACKGROUND: There is no information in the English literature on the outcome of liver cirrhotic patients who have undergone instrumented lumbar surgery. PURPOSE: To review the results of instrumented lumbar surgery in patients with liver cirrhosis and determine the surgical risk factors in this group of patients. STUDY DESIGN: A retrospective study for comparison between two cohorts (liver cirrhosis vs. nonliver cirrhosis). PATIENT SAMPLE: Fifty-eight patients. OUTCOME MEASURES: Child-Turcotte-Pugh scale was used to assess the patients' hepatic functional reserve. The clinical outcomes were evaluated by the five-grade patient-centered general outcome assessment questionnaire. Any event that led to reoperation, requirement of intensive care, prolonging of the hospital stay (more than 14 days), or admission after discharge within 30 days of surgery was defined as a perioperative complication. METHODS: Between 1997 and 2009, patients with liver cirrhosis who had undergone instrumented lumbar surgeries for degenerative lumbar disease were studied. All data were compared with those for gender-, age-, and diagnosis-matched nonliver cirrhosis patients. RESULTS: Liver cirrhotic patients had significantly lower preoperative hemoglobin, white blood cell counts, platelets, and albumin levels and higher prothrombin time and bilirubin level. Instrumented lumbar surgery was associated with significantly more blood loss, a longer hospital stay, and more complications in patients with liver cirrhosis compared with control patients. The final satisfactory rate was higher in the control group but without statistical difference (85% vs. 65%, p=.240). In the cirrhotic group, 22 patients (76%) were Child Class A and 7 patients (24%) were Child Class B; 12 patients developed one or more complications. Patients with Child Class B had a significantly higher incidence of complications than those with Child Class A (p=.006). In patients with Child Class A, those with a score of 6 also had a significantly higher incidence of complications than those with a score of 5 (p<.001). Female gender (p=.035), a low level of albumin (p=.002), presence of ascites (p=.029), and increased blood loss (p=.044) were associated with a higher risk of complications. CONCLUSIONS: The rate of complications after instrumented lumbar surgery was significantly higher in patients with cirrhosis than in control patients, especially in those with 6 or more Child-Turcotte-Pugh points. The surgeon should counsel these patients on the possibility of developing early complications. Several factors were associated with surgical complications and should be addressed by the spine surgeons before or when they perform these elective instrumented lumbar surgeries.

Current status of vertebroplasty for osteoporotic compression fracture.

Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impact the quality of life. Conservative therapy using external bracing, bed rest and analgesics is necessary for pain control in these patients. However, some patients may experience protracted or ongoing pain even with these measures. Surgical treatment is indicated when conservative treatment fails, or in patients with spinal instability or neurologic deficit. Elderly patients often have comorbilities, and because of osteoporosis, high risk of postoperative complications such as implant loosening, and further adjacent fractures. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae under fluroscopic imaging guidance. It was first reported in 1987 for the management of a painful, aggressive hemangioma of a vertebral body. Since then, vertebroplasty has been widely accepted for the treatment of vertebral osteoporotic compression fractures without neurological damage. This article summarizes the advances in vertebroplasty, and discusses the indications, technique, alternative methods, results and complications. The contents include a review of the supporting evidence to provide a comparison of the safety and efficacy of vertebroplasty and kyphoplasty.

Surgical outcomes of degenerative spondylolisthesis with L5-S1 disc degeneration: comparison between lumbar floating fusion and lumbosacral fusion at a minimum 5-year follow-up.

STUDY DESIGN: A retrospective clinical and radiographic study was performed. OBJECTIVE: The purpose of this study was to compare outcomes of patients with degenerative spondylolisthesis and a preexisting degenerative L5-S1 disc treated with a lumbar floating fusion (LFF) versus lumbosacral fusion (LSF). SUMMARY OF BACKGROUND DATA: Fusion for treatment of degenerative spondylolisthesis often ends at the L5 level. These patients usually had a preexisting L5-S1 disc degeneration; however, no literature mentions the role of prophylactic LSF in degenerative spondylolisthesis associated with L5-S1 disc degeneration. METHODS: A total of 107 patients with a minimum 5-year follow-up who had lumbosacral or LFF with pedicle instrumentation for degenerative spondylolisthesis were included. UCLA (University of California, Los Angeles) classification was used to evaluate the radiographic results of the L5-S1 segment. The Oswestry Disability Index (ODI) and modified Brodsky's criteria were used to evaluate patients' clinical results. The incidence of adjacent segment disease (ASD) (includes radiographic and clinical ASD) of both ends was recorded. RESULTS: There were no statistically significant differences in sex, age distribution, or amount of follow-up between the LFF and LSF groups. The LSF group had a higher percentage of patients that underwent total L5 laminectomy with loss of L5-S1 posterior ligament integrity (LSF = 92% vs. LFF = 67%, P = 0.019). The higher incidence of cephalic ASD in the LSF group was statistically significant (LSF = 25% vs. LFF = 9.7%, P = 0.049). Although no patient in the LSF group developed L5-S1 ASD, need for L5-S1 segment revision surgery was not prevented with LSF. Clinical outcomes on the basis of the success rate (LFF = 85.5% vs.LSF = 70.8%, P = 0.103) and ODI difference (LFF = 28.97 ± 15.82 vs. LSF = 23.04 ± 10.97, P = 0.109), there were no statistically significant difference between these two groups. CONCLUSION: Posterior instrumentation with posterolateral LFF for the treatment of degenerative spondylolisthesis with concomitant L5-S1 disc degeneration results in a high percentage of satisfactory clinical results. Extended fusion to the sacrum did not provide a better clinical result. LSF could not reduce the incidence of revision surgery at the L5-S1 segment and involved greater incidence of cephalic ASD.

Transpedicular grafting after short-segment pedicle instrumentation for thoracolumbar burst fracture: calcium sulfate cement versus autogenous iliac bone graft.

STUDY DESIGN: A retrospective clinical and radiographic study was performed. OBJECTIVE: To compare 2 grafting materials of anterior augmentation for thoracolumbar burst fractures: transpedicular cancellous bone (TPCB) grafting and transpedicular calcium sulfate grafting and to decide whether calcium sulfate cement can replace autogenous cancellous bone applied in anterior vertebral body augmentation after posterior short-segment instrumentation. SUMMARY OF BACKGROUND DATA: Additional TPCB grafting was developed as an alternative to prevent early implant failure. However, the results are inconsistent and donor-site complications are a major concern. Calcium sulfate has been offered as a bone substitute for treating patients with metaphysis fractures or bone defect, but the results of application in spinal surgeries are uncertain. METHODS: Fifty-one patients with a single-level thoracolumbar burst fracture for treatment with short-segment pedicle screw fixation were enrolled in the study. Fractures in group 1 patients were reinforced with TPCB (n = 31), and fractures in group 2 patients were augmented with transpedicular calcium sulfate cement (TPCSC; n = 20). All patients were followed-up at least 2 years after surgery. Radiographic parameters and clinical outcomes were compared between the 2 groups. RESULTS: The 2 groups were similar in age, sex, fracture levels, preoperative neurologic status distribution, and the associated injuries. The TPCB group had a longer period of follow-up (52.7 +/- 4.9 vs. 28.6 +/- 3.5 months, P < 0.001). Blood loss and operation time were less in the TPCSC group (247.5 +/- 164.2 vs. 600.0 +/- 403.1 mL, P = 0.001 and 161.7 +/- 28.5 vs. 227.2 +/- 43.6 minutes, P < 0.001). Radiographic parameters and clinical outcomes were similar in both groups. The TPCSC group had no surgical complication, but the TPCB group revealed 2 cases with wound infection after surgery. The failure rate, defined as an increase of 10 degrees or more in loss of correction or implant failure, was also not significantly different (TPCB = 9.6% and TPCSC = 15%; P = 0.565). All patients with partial neurologic deficits initially improved at the final follow-up. CONCLUSION: Additional TPCB grafting after posterior short-segment instrumentation remains a reliable surgical method for correcting and maintaining sagittal alignment and vertebral body height in thoracolumbar burst fractures. Calcium sulfate cement also proved to be an effective bone substitute used in spinal surgeries for patients with thoracolumbar burst fractures.

Transpedicular bone grafting following short-segment posterior instrumentation for acute thoracolumbar burst fracture.

Posterior short-segment instrumentation for thoracolumbar burst fracture is known for a high implant failure rate because of the lack of anterior support. Anterior body augmentation by transpedicular bone grafting has been developed as an alternative to overcome this failure. However, the efficacy of transpedicular bone grafting remains debatable. Between August 2002 and August 2006, 31 patients with a single-level thoracolumbar fracture underwent insertion of posterior short-segment pedicle screws and transpedicular bone grafting. Twenty-one men and 10 women had a mean age of 39.7 years at the time of surgery. All patients were followed up for at least 2 years; the mean follow-up period was 52.7 months. Preoperative computed tomography showed that the mean canal encroachment was 48.1%. The kyphotic angle improved from 20.9 degrees to 3.7 degrees immediately postoperatively. Loss of kyphosis correction was 2.7 degrees before implant removal and 6.2 degrees at final follow-up. The anterior body height was corrected from 50.9% to 86.9% by surgery, but collapsed to 82.2% before implant removal and became 78.1% at final follow-up. The failure of the surgery was defined as an increase of >10 degrees in local kyphosis and/or implant breakage. At last follow-up, no implants had failed, but 3 patients had a loss of correction >10 degrees ; the failure rate was 9.7%. According to the Dennis functional scales, the mean pain score was 1.7, and the mean work score was 2.2 at final follow-up. All 8 patients with partial neurological deficit initially had improvement. Analysis of the results indicated that this technique effectively corrects deformities, restores vertebral height, prevents early implant failure, and provides satisfactory clinical results.