Browsing by Subject "Ilium"

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    ItemOpen Access
    Long-Segment Fusion for Adult Spinal Deformity Correction Using Low-Dose Recombinant Human Bone Morphogenetic Protein-2: A Retrospective Review of Fusion Rates.
    (Neurosurgery, 2016-08) Schmitt, Paul J; Kelleher, John P; Ailon, Tamir; Heller, Joshua E; Kasliwal, Manish K; Shaffrey, Christopher I; Smith, Justin S

    Background

    Although use of very high-dose recombinant human bone morphogenetic protein-2 (rhBMP-2) has been reported to markedly improve fusion rates in adult spinal deformity (ASD) surgery, most centers use much lower doses due to cost constraints. How effective these lower doses are for fusion enhancement remains unclear.

    Objective

    To assess fusion rates using relatively low-dose rhBMP-2 for ASD surgery.

    Methods

    This was a retrospective review of consecutive ASD patients that underwent thoracic to sacral fusion. Patients that achieved 2-year follow-up were analyzed. Impact of patient and surgical factors on fusion rate was assessed, and fusion rates were compared with historical cohorts.

    Results

    Of 219 patients, 172 (78.5%) achieved 2-year follow-up and were analyzed. Using an average rhBMP-2 dose of 3.1 mg/level (average total dose = 35.9 mg/case), the 2-year fusion rate was 73.8%. Cancellous allograft, local autograft, and very limited iliac crest bone graft (<20 mL, obtained during iliac bolt placement) were also used. On multivariate analysis, female sex was associated with a higher fusion rate, whereas age, comorbidity score, deformity type, and 3-column osteotomy were not. There were no complications directly attributable to rhBMP-2.

    Conclusion

    Fusion rates for ASD using low-dose rhBMP-2 were comparable to those reported for iliac crest bone graft but lower than for high-dose rhBMP-2. Importantly, there were substantial differences between patients in the present series and those in the historical comparison groups that could not be fully adjusted for based on available data. Prospective evaluation of rhBMP-2 dosing for ASD surgery is warranted to define the most appropriate dose that balances benefits, risks, and costs.

    Abbreviations

    ASD, adult spinal deformityICBG, iliac crest bone graftOR, odds ratiorhBMP-2, recombinant human bone morphogenetic protein-2RR, risk ratioTCO, 3-column osteotomy.
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    ItemOpen Access
    Morphometric panel regression equations for predicting body mass in immature humans.
    (American journal of physical anthropology, 2018-05) Yapuncich, Gabriel S; Churchill, Steven E; Cameron, Noël; Walker, Christopher S
    OBJECTIVES:Predicting body mass is a frequent objective of several anthropological subdisciplines, but there are few published methods for predicting body mass in immature humans. Because most reference samples are composed of adults, predicting body mass outside the range of adults requires extrapolation, which may reduce the accuracy of predictions. Prediction equations developed from a sample of immature humans would reduce extrapolation for application to small-bodied target individuals, and should have utility in multiple predictive contexts. MATERIALS AND METHODS:Here, we present two novel body mass prediction equations derived from 3468 observations of stature and bi-iliac breadth from a large sample of immature humans (n = 173) collected in the Harpenden Growth Study. Prediction equations were generated using raw and natural log-transformed data and modeled using panel regression, which accounts for serial autocorrelation of longitudinal observations. Predictive accuracy was gauged with a global sample of human juveniles (n = 530 age- and sex-specific annual means) and compared to the performance of the adult morphometric prediction equation previously identified as most accurate for human juveniles. RESULTS:While the raw data panel equation is only slightly more accurate than the adult equation, the logged data panel equation generates very accurate body mass predictions across both sexes and all age classes of the test sample (mean absolute percentage prediction error = 2.47). DISCUSSION:The logged data panel equation should prove useful in archaeological, forensic, and paleontological contexts when predictor variables can be measured with confidence and are outside the range of modern adult humans.
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    ItemOpen Access
    Outcomes and complications of extension of previous long fusion to the sacro-pelvis: is an anterior approach necessary?
    (World neurosurgery, 2013-01) Fu, Kai-Ming G; Smith, Justin S; Burton, Douglas C; Shaffrey, Christopher I; Boachie-Adjei, Oheneba; Carlson, Brandon; Schwab, Frank J; Lafage, Virginie; Hostin, Richard; Bess, Shay; Akbarnia, Behrooz A; Mundis, Greg; Klineberg, Eric; Gupta, Munish; International Spine Study Group

    Background

    Patients with previous multilevel spinal fusion may require extension of the fusion to the sacro-pelvis. Our objective was to evaluate the outcomes and complications of these patients, stratified based on whether the revision was performed using a posterior-only spinal fusion (PSF) or combined anterior-posterior spinal fusion (APSF).

    Methods

    A retrospective, multicenter evaluation of adults (>18 years old) with a history of prior spinal fusion for scoliosis (≥4 levels) terminating in the distal lumbar spine requiring extension of fusion to the sacro-pelvis (including iliac fixation in all cases), with minimum 2-year follow-up, was performed. Patients were stratified based on approach (APSF vs. PSF) and inclusion of pedicle subtraction osteotomy (PSO). The PSF group included patients treated with an anterior interbody fusion done through a posterior approach, whereas patients in the APSF group all had both anterior and posterior surgical approaches. Clinical outcomes were based on the Scoliosis Research Society (SRS-22) questionnaire.

    Results

    Between 1995 and 2006, 45 patients (mean age = 49 years) met inclusion criteria, with a mean follow-up of 41.9 months (range 24 to 135 months). Demographic, preoperative, operative, and postoperative radiographic, SRS-22, and follow-up results were similar between APSF (n=30) and PSF (n=15) groups. The APSF group had more complications (13 of 30 vs. 3 of 15) and a greater number of pseudarthrosis (4 of 30 vs. 0 of 15) than the PSF group; however, these differences did not reach statistical significance. Patients treated with a PSO (n=13) had greater sagittal vertical axis correction (7.7 cm vs. 2.2 cm; P=.04) compared with patients not treated with a PSO (n=32). There were no differences in complication rates or follow-up SRS-22 scores based on whether a PSO was performed (P>.05).

    Conclusions

    Among adults with previously treated scoliosis requiring extension to the sacro-pelvis, PSF produced radiographic fusion and clinical outcomes equivalent to APSF, whereas complication rates may be lower. PSO resulted in greater sagittal plane correction, without an increase in overall complication rates.
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    ItemOpen Access
    Rates of Loosening, Failure, and Revision of Iliac Fixation in Adult Deformity Surgery.
    (Spine, 2022-07) Eastlack, Robert K; Soroceanu, Alex; Mundis, Gregory M; Daniels, Alan H; Smith, Justin S; Line, Breton; Passias, Peter; Nunley, Pierce D; Okonkwo, David O; Than, Khoi D; Uribe, Juan; Mummaneni, Praveen V; Chou, Dean; Shaffrey, Christopher I; Bess, Shay; International Spine Study Group

    Study design

    Retrospective cohort review of a prospective multicenter database.

    Objective

    Identify rates and variations in lumbopelvic fixation failure after adult spinal deformity (ASD) correction.

    Summary of background data

    Traditional iliac (IS) and S2-alar-iliac (S2AI) pelvic fixation methods have unique technical characteristics for their application, and result in varied bio-mechanical and anatomic impact. These differences may lead to variance in lumbopelvic fixation failure types/rates.

    Methods

    ASD patients undergoing correction with more than five level fusion and pelvic fixation, separated by pelvic fixation type (IS vs. S2AI). Fixation fracture or loosening assessed radiographically (Figure 1). Multivariate logistic regression, accounting for significant confounders, was used to examine differences between the two groups for screw loosening/fracture, rod fracture, and revision surgery. Level of significance set at P< 0.05.

    Results

    Four hundred eighteen of 1422 patients were included (IS = 287, S2AI = 131). The groups had similar age, body mass index (BMI), baseline comorbidities, number of levels fused (P>0.05), baseline health related quality of life measures (HRQLs) (short form survey-36, Oswestry Disability Index [ODI], Scoliosis Research Society [SRS-22], numeric rating scale [NRS] leg and back, P>0.05) and deformity (pelvic tilt [PT], pelvic incidence-lumbar lordosis [PI-LL], and sagittal vertical axis [SVA], P> 0.05). The IS group had more unilateral fixation versus S2AI (12.9% vs. 6%; P = 0.02). The overall lumbopelvic fixation failure rate was 23.74%. Pelvic fixation (13.4%) and S1 screw (2.9%) loosening was more likely with S2AI (odds ratio [OR] 2.63, P = 0.001; OR 6.05, P = 0.022). Pelvic screw (2.3%) and rod fracture (14.1%) rates similar between groups but trended toward less occurrence with S2AI (OR 0.47, P= 0.06). Revision surgery occurred in 22.7%, and in 8.5% for iliac fixation specifically, but with no differences between fixation types (P = 0.55 and P = 0.365). Pelvic fixation failure conferred worse HRQL scores (physical component score [PCS] 36.23 vs. 39.37, P= 0.04; ODI 33.81 vs. 27.93, P = 0.036), and less 2 years improvement (PCS 7.69 vs. 10.46, P = 0.028; SRS 0.83 vs. 1.03, P = 0.019; ODI 12.91 vs. 19.77, P = 0.0016).

    Conclusion

    Lumbopelvic fixation failure rates were high following ASD correction, and associated with lesser clinical improvements. S2AI screws were more likely to demonstrate loosening, but less commonly associated with rod fractures at the lumbopelvic region.
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    ItemOpen Access
    Sexual function in older adults following thoracolumbar to pelvic instrumentation for spinal deformity.
    (Journal of neurosurgery. Spine, 2013-07) Hamilton, D Kojo; Smith, Justin S; Nguyen, Tanya; Arlet, Vincent; Kasliwal, Manish K; Shaffrey, Christopher I

    Object

    Sexual function is an often-overlooked aspect of health-related quality of life among older adults treated for spinal deformity. The authors' objective was to assess sexual function among older adults following thoracolumbar fusion with pelvic fixation for spinal deformity.

    Methods

    This was a retrospective review of consecutive older adults (≥50 years) treated with posterior thoracolumbar instrumentation (including pelvic fixation) for spinal deformity and with a minimum 18-month follow-up. Patients completed the Changes in Sexual Function Questionnaire-14 (CSFQ-14), Oswestry Disability Index (ODI), and 12-Item Short-Form Health Survey (SF-12).

    Results

    Sixty-two patients (45 women and 17 men) with a mean age of 70 years (range 50-83 years) met the inclusion criteria. Eight women did not complete all questionnaires and were excluded from the subanalysis. The mean number of instrumented levels was 9.8 (range 6-18), and the mean follow-up was 36 months (range 19-69 months). Based on the CSFQ-14, 13 patients (24%) had normal sexual function, and 8 (15%), 10 (19%), and 23 (42%) had mild, moderate, and severe dysfunction, respectively. Thirty-nine percent of patients reporting severe sexual dysfunction did not have available partners-23% because of a partner's death and 16% because of a partner's illness)-or had significant medical comorbidities of their own (48%). Thirty-nine percent of assessed patients had either no or only mild sexual dysfunction. Patients with minimal or mild disability tended to have no or mild sexual dysfunction.

    Conclusions

    The authors of this study assessed sexual function in older adults following surgical correction of spinal deformity that included posterior instrumented fusion and iliac bolts. Nearly 40% of assessed patients had either no or only mild sexual dysfunction, suggesting that despite an older age and extensive spinopelvic instrumentation, it remains very possible to maintain or achieve satisfactory sexual function.
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    ItemOpen Access
    The use of allograft and recombinant human bone morphogenetic protein for instrumented atlantoaxial fusions.
    (World neurosurgery, 2014-12) Hood, Brian; Hamilton, D Kojo; Smith, Justin S; Dididze, Marine; Shaffrey, Christopher; Levi, Allan D

    Background

    Iliac crest autograft is the historic gold standard for bone grafting, but is associated with a significant patient morbidity. Fusion rates of C1-C2 up to 88.9% using allograft and 96.7% using autologous iliac crest bone graft can be achieved when combined with rigid screw fixation. We sought to determine our fusion rate when combining allograft with recombinant human bone morphogenetic protein-2 (rh-BMP2) and rigid screw fixation.

    Methods

    We reviewed our experience using allograft, bone morphogenetic protein (rh-BMP2) and screw fixation of C1-C2 in 52 patients and examined indications, surgical technique, fusion rates, and complications. In 28 patients, corticocancellous allograft pieces were laid along decorticated bone after a C2 neurectomy was performed. In 24 patients, unicortical iliac crest allograft was precision-cut to fit between the C1 lamina and C2 spinous processes.

    Results

    Fifty-two C1-C2 fusions were performed with allograft, rh-BMP2, and rigid screw fixation. There were 25 female and 27 male patients ranging in age from 6 to 92 years (mean, 65.8 years). Operative indications included trauma (56%), degenerative disease (21%), rheumatoid arthritis (15%), congenital anomalies (6%), and synovial cyst (2%). The mean follow-up was 23.9 ± 2.1 months (range, 2-55 months). The mean dose of rh-BMP2 used for all patients was 4.5 mg (range, 2.2-12 mg). In patients who achieved sufficient follow-up, 100% achieved solid fusion: 45/50 Lenke A, 5/50 Lenke B. There were no known complications attributable to the use of rh-BMP2.

    Conclusions

    The use of small doses of rh-BMP2 added to allograft in addition to rigid screw fixation is a safe and highly effective means of promoting a solid fusion of the atlantoaxial complex and spares the patient the morbidity of iliac crest harvest.