Harvinder S Sandhu

Hospital for Special Surgery, New York, New York, United States

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Publications (90)171.11 Total impact

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    ABSTRACT: Wound infection after spine surgery is a debilitating complication. Local placement of vancomycin powder into the surgical wounds prior to closing of the fascia has been introduced as a method to reduce deep infection rates. The infection rates of all the patients who were treated with intra-operative local vancomycin between June 2012 and June 2013 were compared to all cases that were not treated with vancomycin between January 2009 and December 2010. Patients for both groups were operated by four senior, fellowship-trained spine surgeons with a combined experience of 55 years of practice at a referral orthopedic center. Patients' charts and microbiology reports were reviewed. 1224 cases were performed with the use of vancomycin. The average age was 56.3 years (SD -13.2; NS). The male to female ratio was 1:1.12 (NS). 2253 cases were performed without the use of vancomycin. The average patient age was 57.1 years (SD 14.5). The male to female ratio was 1:1.14. There were 30 cases of deep infections needing a surgical irrigation and debridement without vancomycin versus 5 when vancomycin was used (P = 0.04). Infections in patients treated with vancomycin were not vancomycin-resistant bacteria. In conclusion, the use of vancomycin reduces the rate of deep wound infections and irrigation and debridement procedures after spine surgery in a referral center among surgeons with a high surgical volume.
    No preview · Article · Aug 2015 · European Spine Journal
  • Sohrab S Virk · J Brad Elder · Harvinder S Sandhu · Safdar N Khan
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    ABSTRACT: Cost effectiveness analysis using a Markov model with inputs from published literature. To learn which graft or hardware option used in a single-level anterior cervical discectomy and fusion (ACDF) is most beneficial in terms of cost, quality of life and overall cost effectiveness. Options studied were autograft (auto), allograft (allo) and polyetheretherketone cages (PEEK) for cervical fusion. ACDF is commonly used to treat cervical myelopathy and/or radiculopathy. No study has compared the cost effectiveness of auto, allo and PEEK in one-level ACDF. A literature review provided inputs into a Markov decision model to determine the most effective graft or hardware option for one-level ACDF. Data regarding rate of complications, quality adjusted life years gained (QALYs) and cost for each procedure type was collected. The Markov model was first run in a base case, using all currently available data. The model was then tested using 1-way and 2-way sensitivity analyses to determine the validity of the model's conclusions if specific aspects of model were changed. This model was run for 10 years postoperatively. The cost per QALY for each option in the base case analysis was $3328/QALY for PEEK, $2492/QALY for auto, and $2492/QALY for allo. All graft/hardware options are cost effective ways to improve outcomes for patients living with chronic neck pain. For graft/hardware options the most cost-effective option was allo. The incremental cost-effectiveness ratio (ICER) for PEEK compared to auto or allo was greater than $100,000/QALY. Allo is the most cost-effective graft/hardware option for ACDF. Compared to living with cervical myelopathy and/or radiculopathy, ACDF using any graft or hardware option is a cost-effective method of improving the quality of life of patients. PEEK is not a cost-effective option compared to allo or auto for use in ACDF.
    No preview · Article · Mar 2014 · Journal of spinal disorders & techniques
  • Sohrab Virk · Harvinder S Sandhu · Safdar N Khan
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    ABSTRACT: : Statistical decision model. : To determine the most cost-effective graft option in spinal fusion. : Spinal fusion has been shown to be an effective technique to treat lumbar degenerative spondylolisthesis. There have been significant advances in bone graft options to improve outcomes related to spinal fusion. RhBMP-2 (RhBMP), iliac crest bone graft (ICBG), local bone alone (LBG), demineralized bone matrix with local bone (DBM), local bone with corticocancellous allograft chips (CCA) have all been used as graft options. There has not been significant research in which graft option is most cost effective. : A Markov decision model has been created to identify the most cost-effective graft option for use in spinal fusion to treat 1-level (L4-L5) degenerative spondylolisthesis in a cohort of 60-year-old patients. Costs and effectiveness of successful spinal fusion surgery and revision surgery associated with each graft option was estimated through published data. The quality adjusted life years (QALYs) from these surgeries were compared with the amount of QALYs associated with living with chronic back pain. : In the base case, the incremental cost-effective ratio for each graft option when compared with living with chronic back pain was $21,308/QALY for ICBG, $16,595/QALY for RhBMP, $21,204/QALY for LBG, $21,287/QALY for DBM, and $28,153/QALY for CCA. Therefore, the most cost-effective graft option in the base case was RhBMP. Sensitivity analysis shows that RhBMP is not the most cost-effective option if the revision rate is significantly raised. If the cost of treatment with RhBMP rises >$42,250 then LBG becomes the likely cost-effective treatment. : RhBMP is the most cost-effective graft option for L4-L5 fusion for degenerative spondylolisthesis largely due to the reduced rate of revision spine surgery. The increased upfront cost and list of complications associated with RhBMP is offset by the reduced rate of revision surgery.
    No preview · Article · Jul 2012 · Journal of spinal disorders & techniques
  • Article: Letters.
    Scott D Boden · Harvinder Sandhu · Thomas A Zdeblick

    No preview · Article · Sep 2010 · Spine
  • Source
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    ABSTRACT: A novel rat model was used to investigate the effect of nitric oxide synthase inhibition in posterior spinal fusion augmented with recombinant human bone morphogenetic protein-2. Nitric oxide (NO) has important physiological functions including the modulation of fracture healing. Recombinant human BMP-2 (rhBMP-2) enhances spinal fusion. It is not known whether nitric oxide has a role in rhBMP-2 enhanced spinal fusion and remodeling. A novel rat intertransverse fusion model was created using a defined volume of bone graft along with a collagen sponge carrier, which was compacted and delivered using a custom jig. The control groups consisted of a sham group (S, n = 20), an autograft + carrier group (A, n = 28) and a group consisting of 43 μg of rhBMP-2 mixed with autograft + carrier (AB, n = 28). Two experimental groups received a nitric oxide synthase (NOS) inhibitor, N G-nitro l-arginine methyl ester, in a dose of 1 mg/ml ad lib in the drinking water (AL, n = 28) and one of these experimental groups had rhBMP-2 added to the graft mixture at the time of surgery (ALB, n = 28). Rats were killed at 22 and 44 days, spinal columns subjected to radiology, biomechanics and histology. On a radiographic score (0–4) indicating progressive maturation of bone fusion mass, no difference was found between the A and AL groups, however, there was a significant enhancement of fusion when rhBMP-2 was added when compared to the A group (P < 0.001). However, on day 44, the ALB group showed significantly less fusion progression when compared to the AB group (P < 0.01). There was a 25% (P < 0.05) more fusion-mass-area in day 44 of ALB group when compared to day 44 of the AB group indicating that NOS inhibition delayed the remodeling of the fusion mass. Biomechanically, the rhBMP-2 groups were stiffer at all time points compared to the NOS inhibited groups. Decalcified histology demonstrated that there was a delay in graft incorporation whenever NOS was inhibited (AL and ALB groups) as assessed by a 5 point histological maturation score. In a novel model of rat intertransverse process fusion, nitric oxide synthase modulates rhBMP-2 induced corticocancellous autograft incorporation.
    Full-text · Article · Jun 2010 · European Spine Journal
  • Harvinder Sandhu · Arno Hummel · J. Patrick Johnson

    No preview · Article · Oct 2009 · The Spine Journal
  • Safdar N Khan · Matthew J Mermer · Elizabeth Myers · Harvinder S Sandhu
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    ABSTRACT: Compared with nonfunded or peer-reviewed funded projects, industry-sponsored clinical trials have traditionally been associated with more positive results. This relationship has been extensively studied in the nonsurgical literature. Although a few authors have addressed specialties, little has been reported on orthopedic clinical trials and their association with funding, study outcome, and efforts to reduce bias after randomization across journals of multiple subspecialties. For the study reported here, we selected 5 major orthopedic subspecialty journals: Journal of Bone and Joint Surgery (American Volume), Spine, Journal of Arthroplasty, Journal of Orthopaedic Trauma, and American Journal of Sports Medicine. We chose a 2-year limit for investigation (2002-2004); included all original randomized clinical trials reported in these 5 journals; and examined these trials for their study design, funding source, outcome, bias potential, and conclusion reached. Support for the 100 eligible orthopedic clinical trials was stated as coming from industry (26 trials, 26%), nonprofit sources (19 trials, 19%), and mixed sources (5 trials, 5%); no support was stated in 46 trials (46%), and support was not reported in 4 trials (4%). Of the 26 trials reporting industry support, 22 (85%) were graded as indicating an outcome favorable to the new treatment. The association between industry funding and favorable outcome was strong and significant (P<.001). In almost half of the studies reported in Journal of Bone and Joint Surgery and Spine, measures taken to reduce bias were not documented.
    No preview · Article · Dec 2008 · American journal of orthopedics (Belle Mead, N.J.)
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    ABSTRACT: Retrospective chart review. To examine the incidence of major vascular injury during anterior lumbar spinal surgery, attempt to identify predisposing risk factors, and to discuss management techniques. Major vascular injury can be a catastrophic complication of anterior lumbar spinal surgery. Current procedural terminology codes were used to identify the occurrence of major vascular injury, defined as injury to the iliac vessels, vena cava, and aorta. Once identified, the office record, hospital chart, operative note, and diagnostic test results were reviewed in detail. Three hundred forty-five operations were performed on 338 patients. Incidence of major vascular complication was 2.9% (10 of 345). There were 9 injuries of the common iliac vein and a single aortic injury. Risk factors identified in patients with major vascular injury were current or previous osteomyelitis or discogenic infection (n = 3), previous anterior spinal surgery (n = 2), spondylolisthesis (n = 2; 1 isthmic Grade II, 1 iatrogenic Grade II), large anterior osteophyte (n = 2), transitional lumbosacral vertebra (n = 1), and anterior migration of interbody device (n = 1). Lateral venorrhaphy by suture (n = 6) and hemoclip application (n = 2) was augmented by topical agents, which constituted the sole method of repair on 1 occasion. Magnetic resonance venography demonstrated iliac vein thrombosis in 1 patient. Current or previous osteomyelitis or discogenic infection, previous anterior spinal surgery, spondylolisthesis, osteophyte formation, transitional lumbosacral vertebra and anterior migration of interbody device point to an increased risk of vascular injury during anterior lumbar spinal surgery. Careful handling of the vascular structures and liberal use of topical hemostatic agents can lead to control of hemorrhage and preservation of vascular patency. Routine postoperative surveillance for proximal deep vein thrombosis, by magnetic resonance venography of the pelvic veins and inferior vena cava, should be performed after venorrhaphy.
    No preview · Article · Dec 2007 · Spine
  • Source
    Fengyu Zheng · James C Farmer · Harvinder S Sandhu · Patrick F O'Leary
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    ABSTRACT: A retrospective study of computed tomography (CT) myelographic images in patients with degenerative lumbar spinal stenosis (LSS). To introduce a new technique for the quantitative evaluation of LSS. Advances in hardware and software technology now permit inexpensive digitalization of radiological images, and enable methodologies for quantifying space available for neural elements in spinal canal. However, a valid method with quantitative evaluation of spinal stenosis in living patients has not been developed yet. Preoperative CT myelographic scans of 50 patients with degenerative LSS were collected for retrospective investigation. The patients subsequently underwent lumbar decompressive surgery. They included scans from thoracic vertebra 12 (T12) to sacrum (S1), in which each segment was scanned through both the vertebral body and disk. All CT scan films were digitized using a high-resolution digital camera. ImageTool software was used to measure three parameters: cross-sectional area of dural sac at disk level (A), cross-sectional area of spinal canal at midpedicular level (B), and cross-sectional area of vertebral body (C). The dural sac canal ratio (DSCR) was calculated as A/B x 100%. Low DSCR implied severe dural sac compression with a high degree of stenosis. The spinal canal vertebral ratio (CVR) was also calculated as B/C x 100%. Low CVR implied a low baseline of canal capacity for neural elements. They were calculated from T12 to S1. The study consisted of 26 male and 24 female patients, with an average age of 68.4 (35-97) years. A total of 295 segments were evaluated, of which 118 (40%) were surgically decompressed. There were wide ranges of canal cross-sectional areas (140-475 mm(2)) and dural sac cross-sectional area (54-435 mm(2)). Male patients had a slightly larger canal cross-sectional area than female patients at each level. The mean CVR was found decreased from T12 (26.1%) to L4 (18.3%). This was higher in female than in male patients, especially from T12 to L2 (P < 0.01). There were significant correlations between spinal canal and dural sac cross-sectional area (r = 0.55, P < 0.001), and also between CVR and DSCR (r = 0.31, P < 0.001). Of the levels decompressed, 82% was performed from the level L2 to L5, in which there was no significant difference in canal cross-sectional area and CVR between decompression and nondecompression (P > 0.05). There was a good correspondence between decreasing mean DSCR and increasing percentile of levels decompressed. DSCR represents a useful method for the quantitative diagnosis of lumbar spinal canal stenosis. ImageTool software is a useful tool in measuring spinal morphometry.
    Preview · Article · Oct 2006 · HSS Journal
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    ABSTRACT: Retrospective study. The purposes of this study were: 1) to investigate the validity of bone mineral density measurements with DEXA in patients with adult lumbar scoliosis and 2) to investigate the association between osteoporosis and adult lumbar scoliosis. Osteoporosis and lumbar degenerative scoliosis are phenomena encountered with increased frequency in aging, often concurrently. It has been suggested that scoliosis predisposes to osteoporosis, but degenerative scoliosis could falsely elevate spinal bone mineral density measurements. The feasibility of measuring Cobb's angle in DEXA scans was established in 48 surgical candidates with standing anteroposterior lumbar radiographs and supine DEXA scans. Charts and radiographs of 454 consecutive adult patients evaluated at an osteoporosis center were reviewed thereafter. The association between age, lumbar curve, and various bone density measurements was investigated. Bone density measurements between nonscoliotic and scoliotic patients with and without a history of adolescent scoliosis were compared. Cobb's angle on DEXA scan was measured with an error of 4 degrees and correlated highly with the plain lumbar radiographs. The prevalence of scoliosis was 9.47% in this cohort of patients. Advancing age was associated with an increase in osteoporosis in both scoliotic and nonscoliotic patients. Scoliotic patients demonstrated increased spinal bone mineral density (BMD) measurements compared with nonscoliotic patients, resulting in discrepancies between hip and spine BMD values. This discrepancy correlated with aging and curve magnitude (up to 30% for curves of 43 degrees ). Scoliotic patients demonstrated significantly lower hip BMD values than nonscoliotic. Curve magnitude did not correlate with severity of osteoporosis. Cobb's angle measurements on DEXA scans are reliable and comparable to conventional radiographs. Spinal BMD values are less valuable for monitoring osteoporosis than hip values in scoliotic patients; an increasing discrepancy with age was noted. Scoliotic patients exhibited discordantly high spinal BMD values, despite significant hip osteoporosis. The discrepancy correlated with aging and curve magnitude. Scoliosis was common among the osteoporotic population (9.47%). Lumbar scoliosis is a useful clinical marker for osteoporosis, irrespective of scoliosis history and magnitude. Viable alternatives for osteoporosis evaluation of adult patients with lumbar scoliosis are hip DEXA values, in conjunction with other BMD measurements.
    No preview · Article · Jul 2006 · Spine
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    ABSTRACT: Retrospective study. To assess the difference in the outcome score between a primary surgery to treat lumbar disc herniation and a revision surgery for recurrent herniation at the same location with the use of a validated lumbar spine outcome instrument. Paucity of studies comparing the results of revision discectomy for true recurrent disc herniation at the same location to that reported for primary discectomy. A total of 27 patients who had undergone revision discectomies for recurrent lumbar disc herniations were surveyed to assess their clinical outcomes. Patients were compared with a control group of 30 matched patients who had undergone only a primary discectomy. The spine module of the MODEMS outcome instrument was used to evaluate the patients' satisfaction, their pain and functional ability following discectomy, as well as their quality of life. All patients were also asked whether they were improved or worsened with surgery. Those undergoing revision surgery were asked whether the improvement following the second surgery was more or less than the improvement following the first surgery. Improvement following the repeat discectomy was not statistically different from the improvement that occurred in patients who underwent just the primary operation. Differences in residual numbness/tingling in the leg and/or the foot as well as in frequency of back and/or buttock pain were identified. Based on patient derived outcome data using a validated instrument, revision discectomy is as efficacious as primary discectomy in selected patients.
    No preview · Article · Jul 2006 · Spine
  • J Kenneth Burkus · Harvinder S Sandhu · Matthew F Gornet
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    ABSTRACT: A prospective, nonblinded, multicenter study. To determine the patterns of allograft incorporation and new bone formation after ALIF using stand-alone threaded cortical allograft dowels with either autograft or rhBMP-2. Accelerated healing patterns of allograft dowels have been reported in an animal study and a small human study of ALIF with rhBMP-2 and bone dowels. We enrolled and randomly assigned 131 patients with lumbar spondylosis who were undergoing single-level ALIF with allograft dowels to either the investigational group who received rhBMP-2 (79 patients) or the control group who received autologous bone graft (52 patients). Independent radiologists used plain radiographs and computed tomography scans to evaluate fusion. Allograft incorporation was assessed using a modified Bridwell-Lenke scale, and changes in bone density within the adjacent vertebral bodies were monitored. At 12 months, all investigational patients had radiographic evidence of new bone formation and incorporation of the allografts into the adjacent vertebral endplates; there were no changes in fusion status at 24 months. Fusions were documented in 89% of patients in the control group at 12 months. The percentage declined to 81.5% at 24 months with 10% of the patients in the autograft group showing incomplete healing and 11% having no healing of the allograft dowels. On CT scans, 14 of the investigational patients (14 of 79; 18%) developed a transient, localized area of bone remodeling within the vertebral body adjacent to the allograft dowel. All were healed by 24 months. The transient appearance of these zones had no effect on clinical outcomes. No patient in the control group developed bone remodeling zones. We think that the use of rhBMP-2 is a promising method of facilitating allograft dowel incorporation and new bone formation in patients undergoing ALIF with allograft dowels.
    No preview · Article · May 2006 · Spine
  • Gerard K. Jeong · Harvinder S. Sandhu
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    ABSTRACT: Animal studies and clinical trials have demonstrated the efficacy of rhBMP-2 as an adjunct or substitute to autogenous bone graft in anterior lumbar interbody fusion, posterolateral fusion, and in overcoming inhibitory effects (ketolorac and nicotine) on fusion. Importantly, no serious adverse events or systemic side effects have been observed in clinical trials. Before widespread application of rhBMP-2 can be accepted, future investigations are needed to evaluate its efficacy in various spinal disorders, optimal dose and delivery system, long-term safety profile (immunogenicity, antibody formation), cost-effectiveness of therapeutic growth factors, and non-fusion application in altering the progression of degenerative disc disease.
    No preview · Article · Mar 2006 · Seminars in Spine Surgery
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    ABSTRACT: A posterolateral lumbar fusion model in rats. To study the effects of alendronate on posterolateral lumbar fusion in rats. To our knowledge, there are no studies that show a significant inhibition of manual palpation-assessed spine fusion by alendronate. A total of 75 Sprague-Dawley rats underwent intertransverse fusion with 7-tailbone autograft at L4-L5. Animals received saline (control), alendronate equivalent to human dose (dose1, 5 microg/kg/day), or 10 times the human dose (dose10, 50 microg/kg/day) via subcutaneous osmotic pumps starting the day of surgery. Eight weeks after surgery, animals were euthanized, and fusion was assessed by manual palpation. Radiographic area and optical density of fusion masses were calculated. Histomorphometry was used to assess the percentage area of fusion masses occupied by bone or marrow tissues. Manual palpation fusion rates were lower in alendronate groups (50% and 40%, respectively) than in the control group (95%, P = 0.002). Interobserver and intraobserver kappa values were high (0.97-1.00). There were dose-dependent and statistically significant (P < 0.001) increases in fusion mass area and optical density with increasing alendronate dose. Fusion masses in dose10 animals had significantly higher percent area of bone tissue (P = 0.01) and lower percent area of marrow elements (P < 0.001) when compared to control animals. Alendronate inhibits spine fusion in rats. Fusion masses in alendronate-treated animals appeared radiographically larger and denser than those in control animals despite lower fusion rates. Quantitative histomorphometry confirmed that alendronate inhibited bone graft resorption and incorporation. We recommend that patients undergoing spine arthrodesis should not take alendronate until fusion is achieved.
    No preview · Article · Nov 2005 · Spine
  • Source
    Gerard K Jeong · Harvinder S Sandhu · James Farmer
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    ABSTRACT: The prospect of predictable and reliable oseteogenesis without the need for secondary bone grafting to treat a wide spectrum of spinal disorders is tremendously appealing. Recombinant human bone morphogenic proteins (rhBMP) have been the subject of extensive basic science, animal, and clinical research as a potential therapeutic modality to promote bony fusion. Animal studies and prospective, randomized clinical trials have demonstrated the efficacy of rhBMPs as an adjunct or substitute to autogenous bone graft in the specific treatment of certain spinal conditions. The future role of rhBMPs in spinal surgery applications remains to be determined and will be dependent upon future investigations evaluating 1) the efficacy in a variety of spinal conditions and environments, 2) the optimal dose and delivery system, 3) the long-term safety profile (immunogenicity, antibody formation), and 4) the cost effectiveness of these therapeutic growth factors.
    Preview · Article · Oct 2005 · HSS Journal

  • No preview · Article · Jul 2005
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    ABSTRACT: Recombinant human bone morphogenetic protein-2 soaked into an absorbable collagen sponge (rhBMP-2/ACS) has been shown in a nonhuman primate study and in a pilot study in humans to promote new bone formation and incorporation of an allograft device when implanted in patients undergoing anterior lumbar interbody arthrodesis. However, a larger series with longer follow-up is needed to demonstrate its superiority to autogenous iliac crest bone graft. Between 1998 and 2001, a two-part, prospective, randomized, multicenter study of 131 patients was conducted to determine the safety and efficacy of the use of rhBMP-2/ACS as a replacement for autogenous iliac crest bone graft in anterior lumbar spinal arthrodesis with threaded cortical allograft dowels. Patients were randomly assigned to a study group that received rhBMP-2/ACS or to a control group that received autograft. The clinical and radiographic outcomes were determined with use of well-established instruments and radiographic assessments. The patients in the study group had significantly better outcomes than the control group with regard to the average length of surgery (p < 0.001), blood loss (p < 0.001), and hospital stay (p = 0.020). Fusion rates were significantly better in the study group (p < 0.001). The average Oswestry Disability Index scores, Short-Form-36 physical component summary scores, and low-back and leg-pain scores were significantly better in the study group (p < 0.05). In patients undergoing anterior lumbar interbody arthrodesis with threaded allograft cortical bone dowels, rhBMP-2/ACS was an effective replacement for autogenous bone graft and eliminated the morbidity associated with graft harvesting.
    No preview · Article · Jun 2005 · The Journal of Bone and Joint Surgery
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    ABSTRACT: Computerized frameless stereotactic image-guidance has been used in recent years to improve the accuracy and safety of pedicle screw placement during spine surgery. Because the possibility of intervertebral motion exists, and because the patient is usually in a different position when preoperative imaging is performed compared with the operative position, it has been suggested that the imaging model of the complete lumbar spine and the surgically exposed lumbar spine may be significantly discordant. Consequently, current protocols suggest registering each spinal level (single-level registration) separately before pedicle screw placement at that level, a time-consuming process. To assess the accuracy of single-time multilevel registration for multilevel pedicle screw placement during image-guided, computer-assisted spine surgery, in the setting of degenerative disorders of the lumbar spine. This is a prospective clinical and radiological study of 45 patients with degenerative disorders of the lumbar spine who underwent instrumented fusion with the use of single-time multilevel registration computer-assisted, image-guided tomography. The accuracy of the pedicle screws placement was confirmed on the basis of a protocol that included intraoperative spontaneous electromyographic (EMG) recordings, direct pedicle visualization, and computer tomography (CT) scans when clinically indicated during the follow-up period. Forty-five consecutive patients who fulfilled the criteria of computer-assisted, image-guided tomography pedicle screw placement for degenerative lumbar spine disease without overt instability. The principal outcome measure was the accuracy of pedicle screw placement with single-time multilevel registration for multilevel pedicle screw placement during image-guided, computer-assisted spine surgery; postoperative CT performed for clinical indications during the follow-up course was used for the assessment of pedicle screw placement. Patients were assessed clinically before and after the operation. Data from 45 consecutive cases of image-guided, computer-assisted lumbar spinal fusion were statistically analyzed to determine the relationship between the number of levels registered during single-time registry and the mean registration error (MRE). Intraoperative spontaneous EMG, direct visualization, and postoperative CT scans were used to assess the accuracy of pedicle screw insertion. None of the patients involved in this study experienced clinical sequelae of improper pedicle screw placement. MREs after surface mapping and after point merge were small (less than 1.00 mm and less than 3.00 mm, respectively). During the intraoperative assessment of the pedicle screws placement, no significant spontaneous EMG activity was recorded and the pedicular walls were found intact in direct visualization. The postoperative CT scans showed in 10 patients accurate placement in 55 of the 57 pedicle screws with expansion of the medial wall in two screws. Single-time, multilevel registration may decrease operative time relative to repeated, single-level registrations, without compromising the increased accuracy of pedicle screw placement afforded by this technique in the setting of degenerative disorders of the lumbar spine. Despite the advantages in computer-guided image surgery, cautious application in the individual patient is recommended until more comprehensive data can be gathered in specific degenerative pathology with overt instability; thus the knowledge of the anatomy remains crucial.
    No preview · Article · May 2005 · The Spine Journal
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    ABSTRACT: Recently developed materials that can enhance fusion rates for posterolateral lumbar arthrodesis may be used alone or in combination with autogenous bone grafts. Novel osteopromotive growth factor preparations are currently under scrutiny; these include autogenous growth factor concentrate, bovine bone-derived osteoinductive protein, and recombinant human MP52. Demineralized bone matrix products may enhance or extend grafts. However, few studies, especially prospective randomized clinical trials, have assessed their efficacy, so it is difficult to compare formulations. Ceramics have been evaluated in animal studies and human clinical trials for a variety of applications in spinal surgery. These materials function best as bone graft extenders or as bioactive osteoinductive material carriers in posterolateral lumbar fusions. They have the advantage of variable porosity, low cost, and ease of manufacture. Hydroxyapatite/tricalcium phosphate ceramics have been shown to perform as well as autogenous bone grafts but with fewer complications.
    No preview · Article · Mar 2005 · The Journal of the American Academy of Orthopaedic Surgeons
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    ABSTRACT: Many approaches are used to repair skeletal defects in reconstructive orthopaedic surgery, and bone grafting is involved in virtually every procedure. The type of bone graft used depends on the clinical scenario and the anticipated final outcome. Autogenous cancellous bone graft, with its osteogenic, osteoinductive, and osteoconductive properties, remains the standard for grafting. However, the high incidence of morbidity during autogenous graft harvest may make the acquisition of grafts from other sources desirable. The clinical applications for each type of bone graft are dictated by the structure and biochemical properties of the graft. An elegant cellular and molecular cascade follows bone transplantation. Bone graft incorporation within the host, whether autogenous or allogeneic, depends on many factors: type of graft (autogenous versus allogeneic, vascular versus nonvascular), site of transplant, quality of transplanted bone and host bone, host bed preparation, preservation techniques, systemic and local disease, and mechanical properties of the graft.
    No preview · Article · Jan 2005 · The Journal of the American Academy of Orthopaedic Surgeons

Publication Stats

4k Citations
171.11 Total Impact Points


  • 1998-2012
    • Hospital for Special Surgery
      • Department of Orthopaedic Surgery
      New York, New York, United States
    • Emory University
      • Department of Orthopaedics
      Atlanta, GA, United States
  • 2000-2010
    • Cornell University
      • Department of Orthopaedic Surgery
      Итак, New York, United States
  • 2005-2008
    • University of California, Davis
      • Department of Orthopaedic Surgery
      Davis, CA, United States
  • 1999-2007
    • Weill Cornell Medical College
      • Department of Orthopaedic Surgery
      New York City, New York, United States
  • 2001
    • New York Career Institute
      New York, New York, United States
  • 1996-1999
    • University of California, Los Angeles
      • Department of Orthopaedic Surgery
      Los Angeles, CA, United States
  • 1997
    • Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
      Torrance, California, United States