bluuebunny/crossref_metadata_2025_split huggingface dataset:
Closed reduction vertebroplasty for the treatment of osteoporotic vertebral compression fractures
Authors: Lee Shih-Tseng , Chen Jyi-Feng 
Published: May 2009

✓ The purpose of this study was to determine the efficacy and feasibility of closed reduction vertebroplasty for the treatment of osteoporotic vertebral compression fractures.
Two hundred consecutive patients (183 women and 17 men) with single-level osteoporotic vertebral compression fracture were included in this study. After induction of general anesthesia, the patient was placed prone on an operating table. Closed reduction of the fractured and kyphotic spine was achieved by extending the table to restore the kyphotic angle and vertebral body (VB) height. Percutaneous vertebroplasty was then performed to treat the fractured vertebra. The results were quantitatively evaluated, according to the concept of estimated VB height. The anterior, middle, and posterior VB heights of the fractured vertebra were measured preoperatively and immediately after surgery by studying plain standing lateral radiographs.
In 162 (81%) of the compression fractures the anterior VB height was restored (57.1 ± 24.8% of lost anterior VB height); in 152 (76%) of the compression fractures the middle VB height was restored (61.4 ± 20.6% of lost middle VB height); and in 52 (26%) of the compression fractures the posterior VB height was restored (51.3 ± 23.1% of lost posterior VB height). In 141 (71.5%) of the compression fractures kyphosis was corrected by 12.5 ± 3.8° [mean 61.6 ± 23.7%]).
Closed reduction vertebroplasty is an efficacious and simple method in the treatment of osteoporotic vertebral compression fracture and was able to restore the VB height and kyphotic angle in postions of fractured vertebrae. Its associated, long-term effects on treated vertebrae, however, need further evaluation.
Impact of interlaminar graft materials on the fusion status in atlantoaxial transarticular screw fixation
Authors: Matsumoto Morio , Chiba Kazuhiro , Nakamura Masaya , Ogawa Yuto , Toyama Yoshiaki , Ogawa Jun 
Published: May 2009

Object. Structural interlaminar graft materials were used for atlantoaxial transarticular screw fixation (TSF), and its impact on the fusion status was investigated.
Methods. Forty-two patients (10 men, 32 women, mean age 51 years, mean follow-up period 45 months; 30 with rheumatoid arthritis, and 12 with os odontoideum) underwent TSF and modified Brooks posterior wiring involving titanium cables. As interlaminar graft materials, autologous bone from posterior iliac crest alone was used in 20 patients (Group A), and a structural spacer (13 ceramic spacers, nine titanium mesh cages) in 22 (Group B). Lateral radiographs were evaluated to determine bone fusion, alignment of the cervical spine, and wire loosening. Solid osseous fusion was obtained in 95% of Group A and 96% of Group B patients. The mean atlantoaxial angle was 19.1 ± 9.7° and 16.7 ± 10.4° before surgery (p = 0.45), and 27.4± 7.8° and 22.1 ± 5.5° after surgery (p = 0.02) in Groups A and B, respectively. Atlantoaxial hyperlordosis (atlantoaxial angle ≥ 30°) was observed in 32% of Group A and 18% of Group B patients (p = 0.26). Postoperative kyphosis occurred in 40% of Group A and 23% of Group B patients (p = 0.28). Loosening of the cable was demonstrated in 50% of Group A and 36% of Group B patients (p = 0.37). In Group B patients maintenance of cervical lordosis was more likely than in those in Group A, although the differences did not reach statistical significance.
Conclusions. These results indicate that structural interlaminar spacers can maintain proper cervical alignment without a decease in the fusion rate; the authors recommend their use in conjunction with TSF.
Calcium phosphate cement leakage after percutaneous vertebroplasty for osteoporotic vertebral fractures: risk factor analysis for cement leakage
Authors: Nakano Masato , Hirano Norikazu , Ishihara Hirokazu , Kawaguchi Yoshiharu , Matsuura Kousou 
Published: May 2009

Object. The purpose of this study was to analyze the risk factors for leakage of calcium phosphate cement (CPC) after vertebroplasty for osteoporotic vertebral fractures and to determine whether the vertebral body (VB) leakage caused any changes in the therapeutic benefits.
Methods. Between August 2000 and April 2002, the authors performed 65 CPC-assisted vertebroplasty procedures in 55 patients with thoracic or lumbar osteoporotic vertebral fractures. Back and low-back pain were evaluated using the visual analog scale and the duration of analgesic medication requirement. Factors related to CPC leakage and the postoperative outcome were analyzed.
There was a small amount of VB CPC leakage in 23 cases. In 10 of 23 cases, leakage into the epidural space was found. Although VB CPC leakage was independently associated with high initial age, female sex, high bone mineral density (BMD), short injury—surgery interval, and injection via the unipedicular route in the logistic regression analysis, there was no factor associated with CPC leakage into the epidural space. Cement leakage into the epidural space reduced the immediate therapeutic effects on fracture-related pain (p = 0.0128). All patients in whom cement leaked into the epidural space had improved by the 2-week follow-up examination.
Conclusions. Advanced initial age, female sex, high BMD, a short interval from injury to surgery, and injection via the unipedicular route may increase the incidence of CPC leakage. Cement leakage into the epidural space attenuated only the immediate therapeutic effects of CPC-assisted vertebroplasty.
Postoperative fibrosis after surgical treatment of the porcine spinal cord: a comparison of dural substitutes
Authors: Haq Iftikharul , Cruz-Almeida Yenisel , Siqueira Edir B. , Norenberg Michael , Green Barth A. , Levi Allan D. 
Published: May 2009

Object. Postoperative adhesion- and fibrosis-induced spinal cord tethering is not uncommon and may be associated with delayed clinical sequelae. Multiple dural substitutes have been used in surgery without a full appreciation of the grafts' adverse effects. The authors conducted a comparative animal experimental study to evaluate the degree of chronic inflammatory reactions, adhesions, and fibrosis caused by the use of four dural substitutes—Surgicel, Durasis, DuraGen, and Preclude.
Methods. Twenty-six pigs weighing 30 to 40 kg underwent a two-level lumbar laminectomy (a midline durotomy, implantation of a 2-cm dural substitute in the subarachnoid space, and watertight dural closure). After 8 weeks the animals were killed, and two independent neuropathologists blinded to the dural substitute group evaluated several sites along the implants, providing descriptions and quantitative scoring of fibrosis, chronic inflammatory reactions, foreign-body reactions, and spinal cord changes. Kruskal—Wallis one-way analysis of variance for ranks corrected for multiple comparisons was used to examine differences among the materials.
Conclusions. The DuraGen dural substitute produced the least amount of inflammation in the subarachnoid space and Preclude generated the most (p < 0.001). Surgicel and DuraGen were completely resorbed on histological sections, but both produced some inflammation, which diminished gradually from the dural implant center. Histological evaluation of the nonresorbed grafts demonstrated that Durasis caused the least degree of inflammatory cell infiltration (p < 0.001). The Preclude dural substitute consistently demonstrated encapsulation and arachnoidal reaction. There was no evidence of implant-related adverse effects on the underlying pia mater and white matter regardless of the substitute type.
Diagnosis-related pitfall of a lateral sacral cyst
Authors: Heckly Anne , Carsin-Nicol Beatrice , Poulain Patrice , Hamlat Abderrahmane 
Published: May 2009

✓ Because physical examination typically demonstrates normal findings in cases of low-back pain, diaglosis of the cause can be challenging. Frequent magnetic resonance imaging studies of the lumbosacral spine can typically lead to discovery of benign diseases and thus misinterpretation of these images.The authors report an unusual case in which a functional ovarian cyst was incidentally associated with a perineural cyst and mimicked a lateral sacral meningocele. In light of this, the authors recommend repeated examinations to avoid mistakes.
Foraminal deposition of calcium pyrophosphate dihydrate crystals in the thoracic spine: possible relationship with disc herniation and implications for surgical planning
Authors: Paolini Sergio , Ciappetta Pasquale , Guiducci Antonio , Principi Massimo , Missori Paolo , Delfini Roberto 
Published: May 2009

✓ The authors report two cases of nodular calcium pyrophosphate dihydrate (CPPD) crystal deposition close to the thoracic neural foramen, which caused chronic radiculopathy. Preoperatively, the lesions were interpreted as calcified disc herniations. Both patients underwent surgery in which an extended transfacet pedicle-sparing approach was used. Incision of the posterior longitudinal ligament released soft degenerated material. In both cases, histological examination showed abundant degenerative debris along with CPPD crystals.Spinal CPPD deposition is a comparatively rare disease that almost invariably involves the posterior aspect of the spinal canal, typically the ligamentum flavum. The exceptional foraminal location of the lesions reported here, combined with the surgical findings, indicated that the CPPD crystals were deposited on a laterally herniated disc fragment. A distinctive feature in both cases was the soft consistency of the resected tissue. The consistency of the disc material and the location of the lesion in the axial plane (that is, median compared with lateral) are key factors in determining the optimal surgical approach to thoracic disc herniations. In describing consistency, terms such as “calcified” and “hard” have been used interchangeably in the literature. In the cases reported here, what appeared on computerized tomography and magnetic resonance imaging studies to be densely calcified lesions were shown intraoperatively to be soft herniations.The authors' experience underscores that not all densely calcified herniated discs are hard. Although detection of this discrepancy would have left surgical planning for the lateral disc herniations unchanged, it could have altered planning for centrally or centrolaterally located disc herniations.
Recurrent laryngeal nerve palsy during anterior cervical spine surgery: a prospective study
Authors: Jung Axel , Schramm Johannes , Lehnerdt Kai , Herberhold Claus 
Published: May 2009

Object.Recurrent laryngeal nerve (RLN) palsy is a well-known complication of cervical spine surgery. Nearly all previous studies were performed without laryngoscopy in asymptomatic patients. This prospective study was undertaken to discern the true incidence of RLN palsy. Because not every RLN palsy is associated with hoarseness, the authors conducted a prospective study involving the use of pre- and postoperative laryngoscopy.Methods.Prior to anterior cervical spine surgery preoperative indirect laryngoscopy was performed in 123 patients to evaluate the status of the vocal cords as a sign of function of the RLN. To assess postoperative status in 120 patients laryngoscopy was repeated, and in cases of vocal cord malfunction follow-up examination was conducted 3 months later.In the group of 120 patients who attended follow-up examination, two (1.6%) had experienced a preoperative RLN palsy without hoarseness. Postoperatively the rate of clinically symptomatic RLN palsy was 8.3%, and the incidence of RLN palsy not associated with hoarseness (that is, clinically unapparent without laryngoscopy) was 15.9% (overall incidence 24.2%). At 3-month follow-up evaluation the rate had decreased to 2.5% in cases with hoarseness and 10.8% without hoarseness. Thus, the overall rate of early persisting RLN palsy was 11.3%.Conclusions.Laryngoscopy revealed that the true incidence of initial and persisting RLN palsy after anterior cervical spine surgery was much higher than anticipated. Especially in cases without hoarseness this could be proven, but the initial incidence of hoarseness was higher than expected. Only one third of new RLN palsy cases could be detected without laryngoscopy. Resolution of hoarseness was approximately 70% in those with preoperative hoarseness. The true rate of RLN palsy underscores the necessity to reevaluate the surgery- and intubation-related techniques for anterior cervical spine surgery and to reassess the degree of presurgical patient counseling.
Surgical technique and results of endoscopic anterior spinal canal decompression
Authors: Beisse Rudolf , Mückley Thomas , Schmidt Meic H. , Hauschild Matthias , Büren Volker 
Published: May 2009

Object.Decompression of the spinal canal in the management of thoracolumbar trauma is controversial, but many authors have advocated decompression in patients with severe canal compromise and neurological deficits. Anterior decompression, corpectomy, and fusion have been shown to be more reliable for spinal canal reconstruction than posterior procedures; however, traditional anterior-access procedures, thoracotomy, and thoracoabdominal approaches are associated with significant complications. Endoscopy-guided spinal access avoids causing these morbidities, but it has not been shown to yield equivalent results in spinal canal clearance. This study was conducted to demonstrate the effectiveness of endoscopic spinal canal decompression and reconstruction quantitatively by using pre- and postoperative computerized tomography (CT) scanning.Methods.Thirty patients with thoracolumbar canal compromise underwent endoscopic anterior spinal canal decompression, interbody reconstruction, and stabilization for fractures (27 cases), and tumor, infection, and severe degenerative disc disease (one case each). The mean follow-up period was 42 months (range 24 months–6 years). Neurological examinations, Frankel grades, radiological studies, and intraoperative findings were prospectively collected.Spinal canal clearance quantified on pre- and postoperative CT scans improved from 55 to 110%. A total of 25% of patients with complete paraplegia and 65% of those with incomplete neurological deficit improved neurologically. The complication rate was 16.7% and included one reintubation, two pleural effusions, one intercostal neuralgia, and one persistent lesion of the sympathetic chain.Conclusions.The authors describe the endoscopic technique of anterior spinal canal decompression in the thoracolumbar spine. The morbidities associated with an open procedure were avoided, and excellent spinal canal clearance was accomplished as was associated neurological improvement.
Axial load—dependent cervical spinal alterations during simulated upright posture: a comparison of healthy controls and patients with cervical degenerative disease
Authors: Kimura Shinji , Hesselink John R. , Garfin Steven R. , Kawaji Yoichi , Hasegawa Kazuhiro , Hargens Alan R. 
Published: May 2009

Object. The objectives of this study were to simulate the upright loading condition in the cervical spine by applying a new compression device during supine posture and to assess intervertebral angles and cross-sectional areas of the spinal cord and dural tube before and during axial compression.
Methods. A magnetic resonance (MR) imaging-compatible device was developed to create axial compression with the patient in the supine position. Lateral radiographs were obtained in upright and supine positions with an axial load of 0% (supine) and by applying a cervical compression device at 7, 10, and 13% of body weight (BW) in 18 control individuals and seven symptomatic patients with cervical degenerative disc disease (DDD). Additionally, cervical MR images acquired in 17 controls and 12 patients were compared before and during an axial load of 8.4% BW in terms of anteroposterior diameter and cross-sectional area of the dural sac.
The supine intervertebral angles with loads of 0, 7, 10, and 13% of the individuals' BW relative to upright posture were −8.1 ± 1.3, −2.3 ± 1.4, 1.3 ± 1.9, and 2.8 ± 2°, respectively. Subsequent axial force was interpolated as 8.9% of BW to simulate upright cervical spine alignment. Under an axial loading similar to that created by the upright posture, the dural sac narrowed at the C5–6 interspace in asymptomatic individuals and at the C6–7 interspace in patients with cervical DDD.
Conclusions. This cervical compression device may be a useful tool to simulate upright cervical spinal alignment. The results of this study help in understanding the pathophysiology of symptoms related to cervical degenerative disorders in upright posture.
Atlantoaxial transarticular screw fixation: a review of surgical indications, fusion rate, complications, and lessons learned in 191 adult patients
Authors: Gluf Wayne M. , Schmidt Meic H. , Apfelbaum Ronald I. 
Published: May 2009

Object. In this, the first of two articles regarding C1–2 transarticular screw fixation, the authors assessed the rate of fusion, surgery-related complications, and lessons learned after C1–2 transarticular screw fixation in an adult patient series.
Methods. The authors retrospectively reviewed 191 consecutive patients (107 women and 84 men; mean age 49.7 years, range 17–90 years) in whom at least one C1–2 transarticular screw was placed. Overall 353 transarticular screws were placed for trauma (85 patients), rheumatoid arthritis (63 patients), congenital anomaly (26 patients), os odontoideum (four patients), neoplasm (eight patients), and chronic cervical instability (five patients). Among these, 67 transarticular screws were placed in 36 patients as part of an occipitocervical construct. Seventeen patients had undergone 24 posterior C1–2 fusion attempts prior to referral. The mean follow-up period was 15.2 months (range 0.1–106.3 months).
Fusion was achieved in 98% of cases followed to commencement of fusion or for at least 24 months. The mean duration until fusion was 9.5 months (range 3–48 months). Complications occurred in 32 patients. Most were minor; however, five patients suffered vertebral artery (VA) injury. One bilateral VA injury resulted in patient death. The others did not result in any permanent neurological sequelae.
Conclusions. Based on this series, the authors have learned important lessons that can improve outcomes and safety. These include techniques to improve screw-related patient positioning, development of optimal instrumentation, improved screw materials and design, and defining the role for stereotactic navigation. Atlantoaxial transarticular screw fixation is highly effective in achieving fusion, and the complication rate is low when performed by properly trained surgeons.
Biomechanical comparison of C1–2 posterior fixation techniques
Authors: Hott Jonathan S. , Lynch James J. , Chamberlain Robert H. , Sonntag Volker K. H. , Crawford Neil R. 
Published: May 2009

Object. In a nondestructive, repeated-measures in vitro flexibility experiment, the authors compared the acute stability of C1–2 after placement of C-1 lateral mass and C-2 pars interarticularis (LC1—PC2) instrumentation with that of C1–2 transarticular screw fixation.
Methods. The effect of C-1 laminectomy and C1–2 interspinous cable/graft fixation on LC1—PC2 stability was studied. Screw pullout strengths were also compared. Seven human cadaveric occiput—C3 specimens were loaded nondestructively with pure moments while measuring nonconstrained atlantoaxial motion. Specimens were tested with graft alone, LC1—PC2 alone, LC1—PC2 combined with C-1 laminectomy, and graft-augmented LC1—PC2. Interspinous cable/graft fixation significantly enhanced LC1—PC2 stability during extension. After C-1 laminectomy, the LC1—PC2 construct allowed increased motion during flexion and extension. There was no significant difference in lax zone or range of motion between LC1—PC2 fixation and transarticular screw fixation, but graft-assisted transarticular screws yielded a significantly smaller stiff zone during extension. The difference in pullout resistance between C-1 lateral mass screws and C-2 pars interarticularis screws was insignificant. The LC1—PC2 region restricted motion to within the normal range during all loading modes. Atlantal laminectomy reduced LC1—PC2 stability during flexion and extension.
Conclusions. The instrumentation-augmented LC1—PC2 construct performed biomechanically similarly to the C1–2 transarticular screw fixation. The LC1—PC2 construct resisted flexion, lateral bending, and axial rotation well. The weakness of the LC1—PC2 fixation in resisting extension can be overcome by adding an interspinous graft to the construct.
Biomechanical evaluation of a bioresorbable odontoid screw
Authors: Ames Christopher P. , Crawford Neil R. , Chamberlain Robert H. , Deshmukh Vivek , Sadikovic Belma , Sonntag Volker K. H. 
Published: May 2009

Object.The authors tested the ability of a resorbable cannulated lag screw composed of a polylactide copolymer to repair Type II odontoid fractures. The resorbable screw was evaluated for its ability to restore strength and stiffness to the fractured odontoid process compared with traditional titanium screws.Methods.Type II odontoid fractures were created in 14 human cadaveric C-2 vertebrae by applying a posterolaterally directed load and piston displacement was measured. Seven of these specimens were repaired using metal screws and seven were repaired using resorbable screws. Specimens were reinjured using the same mechanism as the initial fracture. Values of ultimate strength and stiffness during failure were statistically compared between metal and resorbable screws and between initial fracture and reinjury.Conclusions.The stiffness and ultimate strength during initial fracture were significantly greater than those during reinjury in specimens repaired using resorbable screws or titanium screws (p < 0.001). The resorbable and titanium screws both restored 31% of the initial ultimate strength of the intact specimen (p = 0.95). The stiffness of the fractured odontoid process was restored to 15 and 23% of its initial value by repair with resorbable and metal screws, respectively (p = 0.07). The mode of failure in resorbable screws was usually breakage or bending, whereas that in metal screws was consistently cutout of the proximal shaft of the screw through the anterior C-2 vertebral body.