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Biomedical subjects

Francis H Shen

Publications and source records attributed to Francis H Shen.

At least 19 recordsLinked to original sources
PubMed2006

Superior odontoid migration in the Klippel-Feil patient.

Klippel-Feil syndrome (KFS) is an uncommon condition noted primarily as congenital fusion of two or more cervical vertebrae. Superior odontoid migration (SOM) has been noted in various skeletal deformities and entails an upward/vertical migration of the odontoid process into the foramen magnum with depression of the cranium. Excessive SOM could potentially threaten neurologic integrity. Risk factors associated with the amount of SOM in the KFS patient are based on conjecture and have not been addressed in the literature. Therefore, this study evaluated the presence and extent of SOM and the various risk factors and clinical manifestations associated therein in patients with KFS. Twenty-seven KFS patients with no prior history of surgical intervention of the cervical spine were included for a prospective radiographic and retrospective clinical review. Radiographically, McGregor's line was utilized to evaluate the degree of SOM. Anterior and posterior atlantodens intervals (AADI/PADI), number of fused segments (C1-T1), presence of occipitalization, classification-type, and lateral and coronal cervical alignments were also evaluated. Clinically, patient demographics and presence of cervical symptoms were assessed. Radiographic and clinical evaluations were conducted by two independent blinded observers. There were 8 males and 19 females with a mean age of 13.5 years at the time of radiographic and clinical assessment. An overall mean SOM of 5.0 mm (range = -1.0 to 19.0 mm) was noted. C2-C3 (74.1%) was the most commonly fused segment. A statistically significant difference was not found between the amount of SOM to age, sex-type, classification-type, AADI, PADI, and lateral cervical alignment (P > 0.05). A statistically significant greater amount of SOM was found as the number of fused segments increased (r = 0.589; P = 0.001) and if such levels included occipitalization (r = 0.616; P = 0.001). A statistically significant greater amount of SOM was also found with an increase in coronal cervical alignment (r = 0.413; P = 0.036). Linear regression modeling further supported these findings as the strongest predictive variables contributing to an increase in SOM. A 7.20 crude relative risk (RR) ratio [95% confidence interval (CI) = 1.05-49.18; risk differences (RD) = 0.52] was noted in contributing to a SOM greater than 4.5 mm if four or more segments were fused. Adjusting for coronal cervical alignment greater than 10 degrees , five or more fused segments were found to significantly increase the RR of a SOM greater than 4.5 mm (RR = 4.54; 95% CI = 1.07-19.50; RD = 0.48). The RR of a SOM greater than 4.5 mm was more pronounced in females (RR = 1.68; 95% CI = 0.45-6.25; RD = 0.17) than in males. Eight patients (29.6%) were symptomatic, of which symptoms in two of these patients stemmed from a traumatic event. However, a statistically significant difference was not found between the presence of symptoms to the amount of SOM and other exploratory variables (P > 0.05). A mean SOM of 5.0 mm was found in our series of KFS patients. In such patients, increases in the number of congenitally fused segments and in the degree of coronal cervical alignment were strongly associated risk factors contributing to an increase in SOM. Patients with four or greater congenitally fused segments had an approximately sevenfold increase in the RR in developing SOM greater than 4.5 mm. A higher RR of SOM more than 4.5 mm may be associated with sex-type. However, 4.5 mm or greater SOM is not synonymous with symptoms in this series. Furthermore, the presence of symptoms was not statistically correlated with the amount of SOM. The treating physician should be cognizant of such potential risk factors, which could also help to indicate the need for further advanced imaging studies in such patients. This study suggests that as motion segments diminish and coronal cervical alignment is altered, the odontoid orientation is located more superiorly, which may increase the risk of neurologic sequelae.

Adolescent↗
PubMed2006

Growth and differentiation factor-5 (GDF-5) stimulates osteogenic differentiation and increases vascular endothelial growth factor (VEGF) levels in fat-derived stromal cells in vitro.

Fat-derived adult mesenchymal stem cells can differentiate into different phenotypes reflecting their potential to regenerate various skeletal tissues. These properties together with the association of adipose with skeletal tissues formed the basis of our study to establish an experimental model for using fat-derived stromal cells to undergo osteogenic differentiation in vitro under the influence of either growth and differentiation factor-5 (GDF-5) or bone morphogenetic protein-2 (BMP-2). Members of the BMP/GDF family of proteins are known for their ability to elicit skeletal morphogenesis, but little is known about the mechanism whereby these morphogens exert their effect on the osteogenic differentiation of fat-derived stromal cells. We compared the effects of GDF-5 and BMP-2 in their recombinant forms to qualitatively and quantitatively determine their influence on the osteogenic differentiation of fat derived stromal cells by examining the effects on mineralization, extracellular matrix, cell proliferation, biochemistry, and gene expression. We identified that GDF-5 not only promotes osteogenic differentiation of rat fat-derived stromal cells, but also may promote angiogenic activity of stromal cells by increasing vascular endothelial growth factor (VEGF) gene expression in vitro. These data suggest that several distinct regulatory mechanisms may exist in association with osteogenic differentiation.

Adipocytes↗
PubMed2006

Osteogenic differentiation of adipose-derived stromal cells treated with GDF-5 cultured on a novel three-dimensional sintered microsphere matrix.

BACKGROUND CONTEXT: It is well known that under the proper conditions multipotential bone marrow stromal cells are capable of osteogenic differentiation. Recently studies have demonstrated that an analogous subpopulation of cells exist within adipose tissue. Although early studies characterizing these adipose-derived stromal (ADS) cells in culture exist, investigations exploring the characteristics and viability of these cells cultured on a three-dimensional sintered microsphere matrix are absent. PURPOSE: To characterize and investigate the viability of ADS cells cultured on bioengineered three-dimensional sintered microsphere matrices (SMM). STUDY DESIGN: Basic science, laboratory study. PATIENT SAMPLE: Sixty SMM total. Six underwent examination by scanning electron microscopy, 18 for cellular viability, 18 for biochemical assay, and 18 for evaluation by gene expression. OUTCOME MEASURES: The SMM were examined under scanning electron microscopy to evaluate for adherence, migration, and proliferation at 7, 14, and 28 days. Cellular viability was assessed using colorimetric assay for mitochondrial dehydrogenases activity in viable cells (MTS [3-(4,5-dimethylthiazol-2-yl)5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay) at each corresponding time point. Osteoblastic differentiation was determined using biochemical assays for alkaline phosphatase activity and gene expression for alkaline phosphatase (ALP), osteocalcin (OC), and core binding factor alpha-1 (Cbfa1). METHODS: Multipotential ADS cells from adult Sprague Dawley rats were isolated and maintained in media. Sintered microsphere matrices of poly(lactide-co-glycolide) [85:15] were prepared using solvent evaporation technique followed by mechanical sieving and fabricated by heating in metal molds. ADS cells were then seeded on the SMM and cultured in media with growth and differentiation factor-5 (GDF-5). Treated samples and controls were evaluated at 7, 14, and 28 days. Statistical significance was set at p<.05. RESULTS: Multipotential ADS cells were capable of being isolated from adipose tissue. Scanning electron microscopy evaluation revealed cells adherent to the scaffold surface in a monolayer by 7 days. Cytoplasmic extensions were seen linking the cells on adjacent microspheres. Migration and proliferation resulting in extension of the cellular elements into the scaffold was apparent by 14 days. MTS confirmed cell viability within the scaffold throughout the 28-day study. Osteoblastic differentiation was confirmed using biochemical assays for alkaline phosphatase activity and gene expression for ALP, OC, and Cbfa1. CONCLUSIONS: This is the first study to investigate the fate of ADS seeded on a three-dimensional sintered microsphere matrix. The results of this study confirm that ADS cells, when treated with GDF-5, are not only capable of adhering to the bioengineered scaffold, but also remain viable and demonstrated the ability to migrate, proliferate, and subsequently undergo osteogenic differentiation under the conditions described. These early findings support the concept that ADS cells cultured on a SMM may serve as a viable alternative to more traditional methods of bone graft materials.

Adipose Tissue↗
PubMed2006

Classification of congenitally fused cervical patterns in Klippel-Feil patients: epidemiology and role in the development of cervical spine-related symptoms.

STUDY DESIGN: A retrospective cohort and series review. OBJECTIVES: To determine the role of cervical spine fusion patterns on the development of cervical spine-related symptoms (CSS) in patients with Klippel-Feil syndrome (KFS) and evaluate age- and time-dependent factors that may contribute to fused cervical patterns and the development of the CSS. SUMMARY OF BACKGROUND DATA: Although the "hallmark" of KFS is the presence of congenitally fused cervical vertebrae, the epidemiology and role of specific cervical fused patterns are limited. In addition, the incidence of symptoms and various age- and time-dependent factors that are directly attributed to the congenitally fused cervical segments in KFS patients is unknown. METHODS: A radiographic and clinical review of 28 KFS patients at a single institution. Radiographically, Type I patients were defined as having a single congenitally fused cervical segment. Type II patients demonstrated multiple noncontiguous, congenitally fused segments, and Type III patients had multiple contiguous, congenitally fused cervical segments. Clinical records were reviewed for patient demographics, presence and type of symptoms, and clinical course. RESULTS: Twelve males and 16 females were reviewed for clinical follow-up (mean, 8.5 years) and radiographic assessment (mean, 8.0 years). The mean age at presentation was 7.1 years; mean age of onset of CSS was 11.9 years. Clinically, 64% had no complaints referable to their cervical spine. Radiographically, 25%, 50%, and 25% were Type I, Type II, and Type III, respectively. At final clinical follow-up, 2 patients were myelopathic (Type II and Type III) and 2 were radiculopathic (Type II and Type III). Type III patients were largely asymptomatic but were associated with the highest risk in developing radiculopathy or myelopathy than Type I or Type II patients. Axial symptoms were predominantly associated with Type I patients. Myelopathic patients developed initial CSS earlier (meanage, 10.6 years) than patients with predominant axial (mean age, 13.0 years) or radiculopathic symptoms (mean age, 18.6 years) (P > 0.05). Patients with radiculopathy or myelopathy were diagnosed at a mean age of 17.9 years. Type I patients were predominantly females, while males were largely Type III. Surgery entailed 11% of patients, composed of 2 myelopathic patients (Type II and Type III) and 1 radiculopathic patient (Type II). CONCLUSIONS: In our review, 36% of KFS patients had CSS and the majority had axial symptoms. Axial neck symptoms were highly associated with Type I patients, whereas predominant radicular and myelopathic symptoms occurred in Type II and Type III patients. This classification system has promise for early detection for CSS. Activity modification should be stressed in KFS patients at high risk for neurologic compromise.

Adolescent↗
PubMed2006

A novel "four-rod technique" for lumbo-pelvic reconstruction: theory and technical considerations.

STUDY DESIGN: Surgical technique with case example. OBJECTIVE: To report on a novel technique that allows for the placement of 4 separate longitudinal rods across the lumbo-pelvic junction. SUMMARY OF BACKGROUND DATA: Despite advances in surgical techniques and instrumentation, lumbo-pelvic fixation remains a significant challenge. Fusions to the pelvis create long lever arms and generate high forces across the lumbosacral junction, resulting in high rates of screw pullout and implant fracture. In the attempt to achieve better bony fixation, techniques described include the use of bone cement, hydroxyapatite, and expandable screws. Although this process has decreased the incidence of screw pullout, it has not addressed the problem of rod fracture at the lumbo-pelvic junction. METHOD: There are 4 separate longitudinal rods placed across the lumbo-pelvic junction that couples proximal lumbar screw anchors to 4 separate pelvic fixation points. Proximal lumbar fixation anchors are based on alternating Roy-Camille "straight ahead" screws and Magerl "lateral to medial converging" pedicle screws. There are 4 distal pelvic fixation anchors used based on 1 pair of Galveston-like screws and 1 pair of proximal iliac wing screws. RESULTS: Early results of both ex vivo and in vivo reconstruction show that careful insertion of the lumbar and pelvic screws allows for divergent placement of the pedicle screw heads in a manner that 2 longitudinal rods can be placed per side, resulting in a total of 4 longitudinal rods across the lumbo-pelvic junction. Selection of cross-links in various combinations allows for additional axial and torsional stability, depending on the desired reconstruction. CONCLUSION: Longer follow-up is necessary, and biomechanical and finite element studies are needed to show long-term efficacy of this technique, however, early results indicate that such a construct is feasible. Furthermore, depending on the general medical condition of the patient, immediate postoperative weight bearing is possible and reasonable.

Adult↗
PubMed2006

Symptomatic cervical disc herniation in a pediatric Klippel-Feil patient: the risk of neural injury associated with extensive congenitally fused vertebrae and a hypermobile segment.

STUDY DESIGN: A case report. OBJECTIVE: To report the occurrence of a herniated cervical disc following a high-impact activity in a pediatric Klippel-Feil patient who presented with spinal cord compression, myelopathy, and myelomalacia requiring posterior instrumented fusion followed by an anterior discectomy and fusion at the hypermobile nonfused segment. SUMMARY OF BACKGROUND DATA: The primary hallmark of Klippel-Feil syndrome (KFS) is the presence of at least one congenitally fused cervical segment. Studies have reported the potential risk of cervical injury from hypermobility associated with the nonfused cervical segment in KFS. The manifestation of a cervical disc herniation in the pediatric KFS patient is rare. To the authors' knowledge, the development of a symptomatic cervical herniated disc attributed to mechanical fatigue following a high-impact activity has not been addressed in the literature with respect to the pediatric KFS patient having extensive cervical fusion and a hypermobile segment. METHODS: A 16.8-year-old KFS boy with occipitalization of C1 and fusion of C2-C3 and C4-T1 presented with myelopathy, severe cord compression, and myelomalacia stemming from a left-sided herniated cervical disc at C3-C4 with onset following an 8-foot high rooftop jump. On radiographic evaluation, the patient's C3-C4 segment was hypermobile. RESULTS: The patient was operatively managed via a same-day combined posterior-anterior procedure. The posterior aspect of the procedure entailed a posterior lateral mass plate-screw fixation at C3-C4 with autologous iliac crest bone fusion. Anteriorly, a discectomy was performed at C3-C4 with application of an interbody tricortical autograft. After surgery, the patient wore a halo vest for 3 months, followed by a soft collar for an additional 3 months. On final follow-up at 39 months, the patient was asymptomatic with no instrumentation-related complications, fusion of the posterior graft-bed and anterior interbody graft was noted, and cervical alignment was maintained. CONCLUSIONS: A hypermobile segment in the pediatric KFS patient is a risk factor that may lead to cord compression. A symptomatic herniated cervical disc may develop from an excessive mechanical load stress in a pediatric KFS patient with multiple fused segments. In such a patient, a same-day combined posterior-anterior procedure provides cord decompression and stabilizes the spine with a favorable outcome.

Adolescent↗
PubMed2006

Radiographic assessment of segmental motion at the atlantoaxial junction in the Klippel-Feil patient.

STUDY DESIGN: A retrospective review of 33 consecutive Klippel-Feil syndrome (KFS) patients at a single institution. OBJECTIVES: To assess in KFS patients the presence and degree of radiographic segmental motion at the atlantoaxial junction, factors contributing to such motion, and associated clinical manifestations. SUMMARY OF BACKGROUND DATA: Studies suggest that abnormal segmentation in KFS patients may result in cervical hypermobility, increasing the risk of developing neurologic compromise and the need for surgical intervention. The use of the anterior and posterior atlantodens interval (AADI/PADI) has gained interest as a method for assessing atlantoaxial instability and for space available for the cord. Although helpful for identifying instability after trauma, these measurements are not understood in KFS patients. In addition, the effects of the fusion process associated with KFS on atlantoaxial motion and associated clinical findings have not been properly addressed. METHODS: Radiographs were analyzed for the presence of occipitalization, number/location of congenitally fused segments, and the AADI and PADI. RESULTS: There were 15 males and 18 females (mean age, 13.9 years). Occipitalization occurred in 48.5% of patients. A fused C2-C3 segment was noted in 72.7% of cases. More motion with respect to AADI was evident on O-C1 and C2-C3 fusion only patients, which were all asymptomatic. Overall, 24.2% of patients were symptomatic. Mean AADI and PADI difference was 2.0 mm (symptomatic: mean, 1.5 mm; asymptomatic: mean, 2.1 mm) and -1.7 mm (symptomatic: mean, -1.0 mm; asymptomatic: mean, -2.0 mm), respectively (P > 0.05). CONCLUSIONS: Hypermobility of the atlantoaxial junction, as indicated by increased AADI on flexion-extension radiographs, is not necessarily associated with an increased risk for the development of symptoms or neurologic signs in the KFS patient. Occipitalization plays an integral role in the degree of motion at the atlantoaxial region. Greatest AADI values were in patients with occipitalization and a fused C2-C3 segment. The presence of symptoms was not related to the degree of AADI change. Evaluation of the PADI provides additional information for identifying patients at risk for developing symptoms. Nonetheless, KFS patients remain largely asymptomatic.

Adolescent↗
PubMed2006

Recombinant growth/differentiation factor-5 stimulates osteogenic differentiation of fat-derived stromal cells in vitro.

Fat-derived stromal cells can differentiate into various skeletal tissues. Currently the mechanism that determines whether stromal cells differentiate into osteoblasts is unclear and the role of growth/differentiation factor (GDF)-5 in differentiation of fat-derived stromal cells is not fully understood. It appears that the differentiation of stromal cells is greatly enhanced by GDF-5 that plays a role in a variety of musculoskeletal processes such as joint formation, tendon maintenance, and bone formation. Our study showed that GDF-5 promotes the differentiation of rat fat-derived stromal cells into osteogenic lineages in vitro. Furthermore, these findings were confirmed by histology, biochemical assay for alkaline phosphatase activity, and analysis of gene expression. The ability to preferentially stimulate fat-derived stromal cells down the osteogenic pathway holds significance in a variety of clinical scenarios.

Adipose Tissue↗
PubMed2006

Expandable cage placement via a posterolateral approach in lumbar spine reconstructions. Technical note.

The authors describe a technique for inserting an expandable cage via a posterior extracavitary approach while protecting the segmental nerves. The advent of expandable cages has allowed the use of a less invasive anterior access to the spine, thereby decreasing the surgery-induced insult to the patient. In an attempt to minimize this trauma, the authors have used a posterolateral approach that has allowed them to perform neural decompression, anterior reconstruction with an expandable cage, and posterior stabilization with posterior pedicle screws. The authors describe their surgical technique of posterior circumferential decompression, which entails the use of an expandable cage that is inserted at 90 degrees, rotated in place where the corpectomy has been performed, and then expanded with special custom-made tools, thus respecting the segmental nerves of the lumbar spine. One case example is provided to illustrate the technique.

Aged↗
PubMed2006

Nonsurgical management of acute and chronic low back pain.

A variety of nonsurgical treatment alternatives exists for acute and chronic low back pain. Patients should receive appropriate education about the favorable natural history of low back pain, basic body mechanics, and methods (eg, exercises, activity modification, behavioral modification) that can reduce symptoms. Nonprescription medication is efficacious for mild to moderate pain. Nonsteroidal anti-inflammatory drugs, alone or in combination with muscle relaxants, relieve pain and improve overall symptoms of acute low back pain. Exercise therapy has limited value for acute low back pain, but strong evidence supports exercise therapy in the management of chronic low back pain. Moderately strong evidence supports the use of manipulation in acute back pain. Evidence is weak for the use of epidural corticosteroid injections in patients with acute low back pain, strong for short-term relief of chronic low back pain, and limited for long-term relief of chronic low back pain. The use of facet injections in the management of acute low back pain is not supported by evidence, nor is the effectiveness of orthoses, traction, magnets, or acupuncture. Trigger point injections are not indicated for nonspecific acute or chronic low back pain, and sacroiliac joint injections are not indicated in the routine management of low back pain. Conflicting evidence exists regarding the use of transcutaneous electrical nerve stimulation.

Acute Disease↗
PubMed2005

Traumatic fracture-dislocation of C5 on C6 through a previously solid multilevel anterior cervical discectomy and fusion: a case report and review of the literature.

BACKGROUND CONTEXT: Due to the underlying pathology and altered biomechanics, traumatic cervical fractures have been reported in patients with ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis (DISH), ossification of the posterior longitudinal ligament (OPLL), and combination of DISH and OPLL. However, incidence of a fracture-dislocation through a solid multilevel anterior cervical discectomy and fusion (ACDF) construct with no associated underlying pathology of AS, DISH, or OPLL but severe osteopenia has not, to the best knowledge of the authors, been reported in the medical literature. PURPOSE: To report the development of an unstable cervical spine fracture that occurred through a previous multilevel anterior cervical fusion and the challenges associated with the diagnosis and surgical management of these uncommon lesions. STUDY DESIGN/SETTING: A case report and review of the literature. METHODS: A case report entailing the clinical history, operative management, and postoperative course of a 72-year-old male patient with no known AS, DISH, or OPLL who suffered a cervical spine fracture-dislocation, secondary to a motor vehicle accident, through a previous solid three-level ACDF that was performed 20 years earlier. RESULTS: The patient underwent emergent reduction and realignment of the cervical fracture-dislocation, eventual posterior spinal fusion and stabilization with rigid segmental internal fixation, and application of external halo immobilization. At recent follow-up, he has radiographic evidence of fusion and maintenance of sagittal alignment without loss of reduction. CONCLUSIONS: Multilevel cervical fusion constructs are susceptible to traumatic injuries. Many of the same challenges in the management of the previously fused ACDF patient, who sustains a fracture-dislocation, are similar to those found in the patient with mass-inflammatory conditions or metabolic disorders, such as AS, DISH, or OPLL. In many cases, this includes severe osteopenia, long unstable fusion segments, and difficulties associated with prolonged halo vest immobilization. As a result, preoperative surgical planning should take into consideration the difficulties in achieving fracture reduction, decompression, and proper stabilization.

Accidents, Traffic↗
PubMed2005

Multiple and simultaneous spine fractures in ankylosing spondylitis: case report.

STUDY DESIGN: A case report. OBJECTIVE: To report the unique occurrence and treatment of multiple and simultaneous spine fractures in a patient with progressed ankylosing spondylitis and preexisting multilevel spine instrumentation. SUMMARY OF BACKGROUND DATA: Ankylosing spondylitis is a complex inflammatory arthritic condition that renders the spine more susceptible to fracture than individuals who do not have ankylosing spondylitis. To our knowledge, in the patient with ankylosing spondylitis, the occurrence of nonregion-specific multiple and simultaneous spine fractures, and the role of internal instrumentation in subsequent fracture development have not been addressed in the literature. METHODS: An 81-year-old white male with ankylosing spondylitis had 2 low-energy falls, resulting in 3 spine fractures. During the first fall, he had a displaced fracture at the T11-T12 level without a spinal cord injury. Fracture treatment entailed posterior instrumentation with fusion at T8-L2 and immobilization after surgery with a thoracolumbosacral orthosis brace, which led to successful healing of the injury. Approximately 2 years later, the patient had a second fall, and presented with simultaneous displaced fractures at the C6-C7 and L2-L3 levels, and an American Spinal Injury Association-A spinal cord injury. The cervical and lumbar fractures were both treated operatively via a 2-staged approach with posterior segmental instrumentation and fusion at C3-T3 and at L2-L5, respectively. A soft cervical collar and a thoracolumbosacral orthosis brace were worn after surgery. There were no intraoperative complications. RESULTS: Although anatomic reduction and stable fixation of the spinal injuries were achieved, the patient's neurologic status following the second injury remained unchanged. His postoperative course was complicated by pulmonary failure that ultimately resulted in death by the 3-month postoperative time. CONCLUSIONS: Patients with ankylosing spondylitis have a strong susceptibility to spine fracture from minor trauma, which can have devastating outcomes. Nonregion-specific multiple and simultaneous spine fractures can occur, and require thorough radiographic evaluation with imaging of the entire spinal axis, appropriate operative planning, and meticulous perioperative treatment. Preexisting internal spine instrumentation may predispose the ankylosing spondylitis spine to multiple fractures, even following a minor traumatic event. As such, the clinician should be cognizant of the possible existence of multiple and simultaneous fractures in patients with ankylosing spondylitis with preexisting internal spine instrumentation.

Aged, 80 and over↗
PubMed2005

Is autograft the gold standard in achieving radiographic fusion in one-level anterior cervical discectomy and fusion with rigid anterior plate fixation?

STUDY DESIGN: A review of 66 consecutive patients at a single institution who underwent one-level anterior cervical discectomy and fusion (ACDF) with rigid anterior plate fixation with allograft or autograft. OBJECTIVES: To address the efficacy of allograft to autograft with primary respect to fusion rate and secondary attention to risk factors and clinical outcome in patients undergoing one-level ACDF with rigid anterior plate fixation. SUMMARY OF BACKGROUND DATA: Although autograft is considered the gold standard in achieving optimal fusion, when compared with allograft in noninstrumented one-level ACDF and in plated and nonplated multilevel ACDF, the efficacy of allograft to autograft in one-level ACDF with rigid anterior plate fixation is not thoroughly understood. METHODS: Sixty-six consecutive patients (mean age, 45 years) at a single institution who underwent one-level ACDF with rigid anterior plate fixation with allograft (n = 35) or autograft (n = 31) were reviewed for radiographic fusion (mean, 12 months), risk factors, and clinical outcome (mean, 17 months). Smokers entailed 33.3% of the patients, and 45.5% of all patients presented with a work-related injury. An independent blinded observer reviewed at last follow-up lateral neutral and flexion/extension plain radiographs for radiographic fusion and instrumentation integrity. Clinical outcome was assessed on last follow-up and rated according to the Odom criteria. The threshold for statistical significance was established at P < 0.05. RESULTS: Solid fusion was achieved in 63 patients (95.5%). Fusion was noted in 100% of the allograft patients, whereas 90.3% of the autograft cases achieved fusion. No statistically significant difference was noted between allograft to autograft with regard to fusion rate (P > 0.05). Three patients developed nonunions (1 smoker; 2 nonsmokers) and entailed Orion instrumentation. In the one patient who was a nonsmoker with a nonunion, slight screw penetration into the involved and uninvolved interbody spaces was noted. No other intraoperative, postoperative, or radiographic complication was noted. All of the nonunions occurred early in the series. Postoperatively, excellent results were reported in 19.7%, good results in 71.2%, and fair results in 9.1% of the patients. Satisfactory clinical outcome was noted in all nonunion patients. A nonstatistically significant difference was noted with regard to clinical outcome of fused and nonfused patients, demographics, and the presence of a work-related injury (P > 0.05). The impact of smoking was not a factor influencing fusion or clinical outcome in this series (P > 0.05). A statistically significant difference was noted in plate-type on fusion rate (P < 0.05). CONCLUSION: A 100% and 90.3% radiographic fusion rate was obtained for allograft and autograft in one-level ACDF procedures with rigid anterior plate fixation, respectively. Although autograft achieved a higher incidence of nonunion than allograft, this may be attributed to the use of autograft early in the experience of plate application and fixation in this series. The effects of smoking were not found to be a significant factor influencing fusion in these plated patients. In 90.9% of the patients, excellent and good clinical outcome results were reported. The use of allograft in one-level ACDF with rigid plate fixation yields similar and high fusion rates as autograft. The use of allograft bone eliminates complications and pitfalls associated with autologous donor site harvesting. However, the use of autograft is a viable alternative to avoid the risk of infection, disease transmission, and histocompatibility differences associated with allograft. The use of allograft or autograft bone in properly selected patients for one-level ACDF with rigid anterior plate fixation can result in high fusion rates with excellent and good clinical outcomes.

Adult↗
PubMed2004

The use of bilobed porous-coated acetabular components without structural bone graft for type III acetabular defects in revision total hip arthroplasty: a prospective study with a minimum 2-year follow-up.

A prospective analysis was undertaken of 11 hips (in 11 patients) that underwent revision acetabuloplasties with bilobed, porous-coated, acetabular implants without the use of structural bone graft for type III acetabular defects. The average patient age was 66.3 years, with an average follow-up of 38 months (range, 24-49 months). No acetabular components required or are pending revision surgery. Average pain and hip scores improved from 8 and 36 preoperatively to 42 and 89 postoperatively, respectively. Average leg-length differences decreased from 34 mm preoperatively to 7 mm postoperatively. The use of bilobed acetabular components without structural bone graft is a feasible alternative for reconstructing type III acetabular defects, and can provide good short-term clinical results, while reconstructing the hip center and maximizing host-implant contact.

Acetabulum↗