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Isador H Lieberman

Publications and source records attributed to Isador H Lieberman.

At least 19 recordsLinked to original sources
PubMed2006

The use of newly developed real-time PCR for the rapid identification of bacteria in culture-negative osteomyelitis.

We report a case of a culture-negative osteomyelitis in which our newly developed real-time polymerase chain reaction (PCR) could differentiate Staphylococcus aureus from Staphylococcus epidermidis. This is the first report that described the application of this novel assay to an orthopedics clinical sample. This assay may be useful for other clinical culture-negative cases in a combination with a broad-spectrum assay as a rapid microorganism identification method.

Bacteriological Techniques↗
PubMed2006

Radiographic and histologic findings of vertebral augmentation using polymethylmethacrylate in the primate spine: percutaneous vertebroplasty versus kyphoplasty.

STUDY DESIGN: Animal study. OBJECTIVES: To investigate the gross behavior and the histologic effect(s) of polymethylmethacrylate (PMMA) in primate vertebral bodies after percutaneous vertebroplasty and kyphoplasty. SUMMARY OF BACKGROUND DATA: PMMA is known to induce thermal osteonecrosis in exposed bone during tumor surgery and total joint arthroplasty, and barium sulfate as well as PMMA are known to induce a foreign body reaction, but the effects of PMMA on vertebral cancellous bone have not been well documented. Furthermore, little is known about the mechanisms of cement extravasation that occasionally occur during these procedures. Lastly, it is not known if differences exist between vertebroplasty and kyphoplasty with regards to the above occurrences. METHODS: Six living, elderly, female baboons were used in this study. Seven vertebrae from T12 to L6 were investigated in each animal. Two levels underwent vertebroplasty, two underwent kyphoplasty, and one underwent cavity creation only without cement augmentation in each animal. Three animals were killed at 24 hours and three at 26 weeks after surgery. The specimens were examined macroscopically for cement migration, and histologically for evidence of thermal necrosis, foreign body reaction, cement migration, and intravascular extravasation. RESULTS: Small zones of osteonecrosis were observed histologically at the bone-cement interface in only two kyphoplasty (2 of 6) and two vertebroplasty specimens (2 of 5) at 26 weeks after surgery. All of these necrotic segments of bone were associated with new bone formation. Foreign body reactions were observed in all specimens at 26 weeks after surgery, yet none of them was associated with bone resorption. The incidence of cement leak into the spinal canal and adjacent soft tissues was 6 of 11 and 4 of 11 in vertebroplasty specimens and 5 of 12 and 3 of 12 in kyphoplasty specimens, respectively. There was no statistical difference in the incidence of cement leakage into the spinal canal (P = 0.54) and adjacent soft tissues (P = 0.55) between vertebroplasty and kyphoplasty specimens. The incidence of intravascular cement was significantly greater in vertebroplasty (11 of 12, 91%) than in kyphoplasty (5 of 12, 42%) (P = 0.013). CONCLUSIONS: PMMA caused relatively little necrotic exothermal effect. The presence of PMMA with barium sulfate induces a mild foreign body reaction. The use of a balloon tamp creates a void by displacing pieces of bone, which may result in a lower incidence of intravascular cement leak.

Animals↗
PubMed2006

The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

Base Sequence↗
PubMed2006

Kyphoplasty: vertebral augmentation for compression fractures.

Osteoporosis has devastating consequences for individuals and society in terms of suffering, disability, and increased health care expenses. Early diagnosis and treatment of compression fractures with kyphoplasty allow restoration of normal anatomy as much as possible. Vertebral augmentations by kyphoplasty are efficacious treatments for osteoporotic compression fractures. Kyphoplasty minimizes the risk for cement leakage by compacting the cancellous bone to the periphery, sealing off the fracture clefts,and creating a cavity into which cement is poured. This technique may prevent propagation of further fractures by reducing the col-lapsed vertebral bodies toward its native height, normalizing the sagittal spinal alignment and the force transmission along the spine.

Aged↗
PubMed2006

The mechanics of polymethylmethacrylate augmentation.

Osteoporosis frequently leads to vertebral compression fractures. Percutaneous cement augmentation, one recent technique, may alter the biomechanics of the vertebral body and spinal segment. These alterations reportedly predispose the spinal segment to additional vertebral compression fractures. We investigated the changes in segment stiffness and strength after polymethylmethacrylate augmentation. Twelve thoracic segments consisting of five vertebral bodies were divided into two groups, a pure moment group (Group 1) and an eccentric compression group (Group 2). Baseline measurements of stiffness were taken on each segment followed by the creation of an initial vertebral compression fracture during which stiffness and strength were measured. After augmentation, stiffness was again measured. Finally, a second vertebral compression fracture was created measuring stiffness and strength again. Augmentation did not alter stiffness before and after augmentation in either group. Augmentation also did not result in any difference in strength measured at subsequent fracture when compared with strength measured at initial fracture in either group. The augmentation of vertebral compression fractures by kyphoplasty does not alter the stiffness or the strength of the multilevel segments and eccentric compression in contrast to pure moments leads to a lower strength during mechanical testing.

Adult↗
PubMed2006

Bone-mounted miniature robotic guidance for pedicle screw and translaminar facet screw placement: Part I--Technical development and a test case result.

OBJECTIVE: To introduce a new miniature robot (SpineAssist; MAZOR Surgical Technologies, Caesarea, Israel) that has been developed and tested as a surgical assistant for accurate percutaneous placement of pedicle screws and translaminar facet screws. METHODS: Virtual projections in three planes-axial, lateral, and anteroposterior-are reconstructed for each vertebra from a preoperative computed tomographic (CT) scan. On a specially designed graphic user interface with proprietary software, the surgeon plans the trajectory of the screws. Intraoperative fluoroscopic x-rays with targeting devices are then matched with the CT-based virtual images, as well as the surgeon's plan. A clamp is attached to the spinous process or a minimally invasive frame (Hover-T frame; MAZOR Surgical Technologies) is mounted to the iliac crest and one spinous process. The miniature robot is then attached to the clamp and/or frame. On the basis of combined CT scan and fluoroscopic data, the robot aligns itself to the desired entry point and trajectory, as dictated by the surgeon's preoperative plan. RESULTS: A test case in a cadaver lumbar spine was performed in which four screws and two rods were inserted, using a minimally invasive technique, combining the SpineAssist system and Hover-T frame in conjunction with the PathFinder system (Spinal Concept Inc., Austin, TX). The discrepancy between the planned and actual screw trajectories was measured by means of postprocedural CT scan. Overall, the four screws were implanted with an average deviation of 1.02 +/- 0.56 mm (range, 0-1.5 mm) from the surgeon's plan. CONCLUSION: These preliminary results confirm the system's accuracy and support its use in minimally invasive spine surgery applications.

Bone Screws↗
PubMed2005

Vertebroplasty and kyphoplasty affect vertebral motion segment stiffness and stress distributions: a microstructural finite-element study.

STUDY DESIGN: The mechanical behavior of a thoracic motion segment following cement augmentation was studied using the finite-element method. OBJECTIVE: To examine effects of cement augmentation on motion segment stiffness and load transfer. SUMMARY OF BACKGROUND DATA: Vertebroplasty and kyphoplasty procedures are meant to stiffen and strengthen the vertebral body, but the optimal cement volume and placement to achieve these goals without altering load transfer to adjacent segments are unknown. METHODS: A microstructural finite-element model of a vertebral motion segment was constructed from micro-CT images. Microdamage within the vertebral body trabecular structure was modeled using an elasto-plastic modulus reduction scheme. Three motion segment damage models were created: I = 18% apparent modulus reduction (least damage), II = 45%, and III = 85% (most damage); and several one- and two-segment polymethylmethacrylate cement repair strategies (partial fill kyphoplasty, replacement of bone and marrow; and both partial fill and complete fill vertebroplasty, replacement of marrow only) were studied. Average disc and bone stresses and motion segment apparent compressive stiffness were compared with baseline (undamaged and untreated) simulation results. RESULTS: In terms of maximizing stiffness and minimizing stress alterations in the adjacent vertebral body and increasing motion segment apparent stiffness, we found that, other than complete fill, the most effective single-segment cement repair strategy was vertebroplasty on the periphery of the superior segment overlying the disc anulus (<0.1% overall vertebral body bone stress alteration and 83% stiffness increase, respectively, damage Model III). Two-segment vertebroplasty (all repair models) restored motion segment stiffness to baseline levels in all damage models, while single-segment vertebroplasty (all repair models) restored stiffness to baseline levels only in damage Model I. Single- and two-segment kyphoplasty was effective in restoring stiffness to baseline levels for Model I only. Compared with the baseline model, cement augmentation decreased average treated segment bone stresses (up to 66%, complete fill vertebroplasty elasto-plastic modulus reduction Model III), increased average intervertebral disc nucleus stresses (up to 59%, kyphoplasty elasto-plastic modulus reduction Model III), and increased average adjacent segment, endplate region stresses (up to 2.8%, kyphoplasty elasto-plastic modulus reduction Model II). Adjacent (untreated) segment peak bone stresses were increased (up to 45%, kyphoplasty, Model III) in endplate regions underlying the intervertebral disc nucleus. CONCLUSIONS: The damage-repair simulations indicated that cement augmentation improves motion segment stiffness but substantially alters bone stress distributions in treated and adjacent segments.

Aged↗
PubMed2005

Histological evaluation of biopsies obtained from vertebral compression fractures: unsuspected myeloma and osteomalacia.

STUDY DESIGN: A histological evaluation of biopsies obtained from presumed osteoporotic vertebral compression fractures (VCF) to confirm possible osteomalacia after tetracycline labeling. OBJECTIVE: To describe the results of a series of biopsies obtained at the time of vertebral augmentation in presumed osteoporotic VCF, with special reference to the presence of unmineralized bone (osteomalacia) and occult or unconfirmed plasma cell dyscrasia. SUMMARY OF BACKGROUND DATA: Vertebral augmentation is now widely performed as a method to treat osteoporotic or osteolytic VCF. However, the influence of underlying pathology on the effect of treatment is unclear. METHODS: As of October 2003, 178 biopsies were obtained from 142 patients with VCF during 246 kyphoplasty procedures. There were 110 one-level, 28 two-level, and 4 three-level biopsies. Patients included 41 men and 101 women, with an average age of 72 years (range 40-90). The patients consented to this procedure, and 25 received tetracycline (1g/day, in 2 doses separated by 6 days). Vertebral body biopsies were taken using a trephine just before the kyphoplasty procedure. The biopsies were fixed, embedded, and stained with toluidine blue and hematoxylin eosin, and were viewed with transmitted light. Unstained sections were viewed under fluorescent light to detect tetracycline labels. RESULTS: The 178 biopsy levels included: T4 (3), T5 (1), T6 (4), T7 (13), T8 (12), T9 (8), T10 (11), T11 (17), T12 (28), L1 (25), L2 (14), L3 (13), L4 (17), and L5 (12). All specimens showed fragmented bone with variable amounts of unmineralized bone (osteoid), suggesting bone remodeling and/or fracture healing. Woven bone and cartilaginous tissue were often present, representing fracture callus formation. The biopsies obtained from 30 patients (21%), including 4 who received tetracycline, showed significantly increased osteoid, suggesting either increased bone remodeling activity or mineralization defect (osteomalacia). One sample from these 4 patients who received tetracycline showed no tetracycline labels, essentially diagnostic of osteomalacia. The biopsies also provided definitive diagnoses for one case of unsuspected and 3 cases of unconfirmed plasma cell dyscrasia. CONCLUSIONS: The majority of biopsies from this series of patients revealed findings consistent with various stages of fracture healing. Osteoid seams were increased in 30 patients, representing either increased bone remodeling or osteomalacia. More cases with tetracycline labeling will help elucidate the true incidence of osteomalacia in this population. As we confirmed 4 cases of plasma cell dyscrasia, we advocate a biopsy during each first-time vertebral augmentation procedure.

Adult↗
PubMed2005

A molecular gram stain using broad range PCR and pyrosequencing technology: a potentially useful tool for diagnosing orthopaedic infections.

The bacteria associated with orthopaedic infections are usually common gram-positive and gram-negative bacteria. This fundamental grouping of bacteria is a necessary first step in the selection of appropriate antibiotics. Since polymerase chain reaction (PCR) is more rapid and may be more sensitive than culture, we developed a postamplification pyrosequencing method to subcategorize bacteria based on a few nucleotide polymorphisms in the 16S rRNA gene. We validated this method using well-characterized strains of bacteria and applied it to specimens from spinal surgery cases with suspected infections. Lysates of 114 bacteria including 75 species were created following standard cultivation to obtain DNA. The DNA was amplified by a broad-range real-time PCR. The amplicons were evaluated by pyrosequencing and were classified as gram-positive, gram-negative, or acid-fast bacilli based on the first three to five nucleotides sequenced. In addition, clinical cases of suspected infection were obtained from spinal surgery. The results of the "molecular Gram stain" were compared with the results of traditional Gram stain and culture. The lysates of 107 (93.9%) of the bacteria extracts tested were appropriately categorized as gram-positive and gram-negative or as acid-fast bacilli on the basis of this assay. The sensitivity and specificity of this assay were 100% and 97.4% for gram-positive and 88.3% and 100% for gram-negative isolates. All of the five clinical samples were appropriately categorized as containing gram-positive or gram-negative bacteria with this assay. This study demonstrates that high sensitivity and specificity of a molecular gram stain may be achieved using broad-range real-time PCR and pyrosequencing.

Bacterial Infections↗
PubMed2004

Lumbar intervertebral body fusion cages: histological evaluation of clinically failed cages retrieved from humans.

BACKGROUND: Although interbody cages are widely used, there is little histological documentation of the tissue within cages in the human spine. The purpose of this study was to describe the contents of retrieved, clinically failed, interbody cages from human patients, with special reference to the influence of graft type on the viability of bone in the cages. METHODS: Seventy-eight cages that had been retrieved from forty-eight patients were analyzed. There were eight carbon-fiber cages and seventy threaded metal cages. Of the sixty-seven cages for which information about grafting was available, fifty-six had been packed with autograft only, six had local autograft mixed with demineralized bone matrix, four had allograft, and one had demineralized bone matrix only. The indications for cage retrieval included a failed fusion, malposition or migration of the cage, trauma (a compression fracture at the fusion site), low-back pain, progressive spondylosis, nerve-root impingement, and/or infection. The cages had been in situ for an average of twenty-two months. Undecalcified sections through the center of each plastic embedded cage were reviewed, and the approximate areas occupied by viable bone, necrotic bone, fibrocartilage, hyaline cartilage, fibrous tissue, and graft substitute were visually estimated. Debris particles were estimated by a semiquantitative scoring system. RESULTS: Seventy-one of the seventy-eight cages showed evidence of vascular ingrowth and areas of histologically viable bone, representing incorporating bone graft. The average area occupied by viable bone was 44% (range, 0% to 80%). In some cages, relatively large fragments of cortical bone graft were associated with only minimal new-bone formation. Fibrocartilage occupied up to 50% of the available area in these failed cages. Some cages also contained small fibrocartilage seams connecting segments of bone in a pattern that suggested motion in vivo. In thirty-one of the seventy-eight cages, > or = 5% of the available area was occupied by hyaline cartilage, probably from vertebral end plates or facet joints. CONCLUSIONS: While this study was not designed to test the efficacy of cages or of bone graft, the prevalence of hyaline and fibrocartilage in these failed cages illustrates the importance of graft and graft-site preparation to maximize bone-graft incorporation. LEVEL OF EVIDENCE: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Adult↗
PubMed2003

Histologic evaluation of human vertebral bodies after vertebral augmentation with polymethyl methacrylate.

STUDY DESIGN: Histologic documentation of vertebral bodies retrieved from human patients. OBJECTIVES: The purpose of this study is to illustrate the histologic findings of two cases in which vertebroplasty and/or kyphoplasty had been performed. SUMMARY OF BACKGROUND DATA: There are a number of controversies to vertebral augmentation, including the use of inflatable bone tamps, use of nonstandardized polymethylmethacrylate (PMMA) preparations, the extent and significance of thermal necrosis, any foreign body reaction, and cement extravasation. METHODS: Four vertebral bodies from two cases ranging from 1 month to 2 years after surgery were analyzed histologically. Microscope slides of retrieved vertebral bodies were reviewed with special reference for evidence of thermal necrosis, foreign body reaction, migration of cement, cement voids and fractures, and for the influence of the bone tamp on adjacent bone. RESULTS: The cancellous bone around the cement of the kyphoplasty specimen showed good density, suggesting that the tamping had displaced bone, essentially autografting the space around the cement. Bone immediately around the cement did not show extensive necrosis, but there were a few spicules of necrotic bone associated with creeping substitution, suggesting either thermal effect, the original fracture, or displacement of bone by the procedure. Foreign body giant cells and macrophages were identified in the fibrous membrane around the PMMA in all segments. These cells contained material consistent with cement particles and/or barium sulfate. Particles were also present within vascular spaces. CONCLUSIONS: To our knowledge, these cases are among the first published reports of human histology after vertebral cement augmentation and have implications concerning the nature of the surgical procedures as well as the material used for injection.

Adult↗
PubMed2003

Histology of tissues within retrieved human titanium mesh cages.

STUDY DESIGN: Histologic documentation of contents within retrieved, failed human titanium mesh cages. OBJECTIVES: The purpose of this study is to describe the contents of a series of retrieved, clinically failed titanium mesh cages from human patients. SUMMARY OF BACKGROUND DATA: The use of interbody fusion cages is gaining rapid acceptance, but there is little histologic documentation of tissue within retrieved cages. METHODS: Eleven Titanium Surgical Mesh Cages (Harms; DePuy AcroMed, Raynham, MA) retrieved from 10 patients were histologically analyzed. Indications for cage retrieval included failed fusion or failed fusion with instrumentation failure. The cages had been in situ from 2 to 47 months. Histologic sections were reviewed qualitatively, and the approximate percent of area in the cage occupied by viable bone, necrotic bone, fibrocartilage, hyaline cartilage, fibrous tissue, and bone graft substitute was visually estimated. Particles of metal debris were estimated by a semiquantitative scoring system. RESULTS: All cages except one showed evidence of vascular ingrowth and areas of histologically viable bone, representing incorporating bone graft. At least a few particles of debris were present in 9 of 11 cages. Fibrocartilage of probable intervertebral disc origin ranged from 0% to 70% of the available area. Several cages contained small seams of fibrocartilage connecting segments of bone in a pattern that suggested a response to motion. CONCLUSIONS: Mean viable bone area within 11 retrieved, human titanium mesh cages was approximately 31%. Seams of fibrocartilage within the cages may represent tissue differentiation in response to bending or compressive load.

Adult↗
PubMed2003

Kyphoplasty for vertebral compression fractures: 1-year clinical outcomes from a prospective study.

OBJECT: Over the past 15 years, vertebroplasty has emerged as a treatment for vertebral compression fractures. This technique, however, does not restore vertebral height and is associated with a high rate of cement leakage. Recently, kyphoplasty was developed in an effort to circumvent this problem. Although its immediate results have been reported, it is unclear whether the benefits endure. METHODS: Seventy-eight consecutive patients underwent 188 kyphoplasty procedures. The patients responded to Short Form-36 (SF-36) questionnaires, a visual analog scale (VAS) for pain rating, and the Oswestry disability index (ODI) instrument; additionally they underwent detailed neurological and radiographic examinations pre- and postoperatively. The preoperative SF-36, VAS, and ODI scores, the neurological examination results, and the radiographic data were compared with the postoperative findings. Thirteen patients died of disease progression or unrelated illness. Of the surviving patients, complete data were available in 62% (minimum follow-up period 12 months, mean 18 months). Complications included one myocardial infarction and five cases of asymptomatic cement extravasation. No case of neurological deterioration occurred during the follow-up period. Significant improvements in seven measures of the SF-36 inventory as well as on the ODI and VAS were noted early postoperatively, and these persisted throughout the follow-up period, despite a statistically insignificant decline in the measure of general health at last follow-up examination. CONCLUSIONS: Kyphoplasty is an effective treatment for vertebral compression fractures. The benefits presented in the early postoperative period and persisted at 1 year posttreatment.

Adult↗
PubMed2003

Minimally invasive treatments of osteoporotic vertebral compression fractures: vertebroplasty and kyphoplasty.

Although nonsurgical treatment of osteoporotic vertebral compression fractures, including medication, exercise, bracing, and bed rest, have been reasonably effective, vertebroplasty and kyphoplasty have evolved as valuable adjunctive treatment options. Over the past decade, vertebroplasty, which involves the percutaneous injection of bone cement directly into the fractured vertebral body, has been used as a treatment for painful osteoporotic vertebral body compression fractures, a leading cause of morbidity in the elderly. Kyphoplasty, another minimally invasive procedure that allows for correction of spinal deformity and for controlled cement filling of the fractured vertebral body, involves the percutaneous cannulation of the vertebral body followed by the placement of an inflatable bone tamp. Reported results for both vertebroplasty and kyphoplasty suggest rapid improvement in pain and physical functioning in patients with osteoporotic vertebral compression fractures. Kyphoplasty allows for low-pressure cement injection and affords the opportunity to correct spinal deformity. Further study is required to define the precise indications, timing, and relative merits of these techniques.

Contraindications↗