bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of hole preparation on screw pullout resistance and insertional torque: a biomechanical study
Authors: Öktenoǧlu B. Tunç , Ferrara Lisa A. , Andalkar Niteen , Özer A. Fahir , Sarioǧlu Ali Çetin , Benzel Edward C. 
Published: May 2009

Object. The authors conducted a study to assess the effect of a pilot hole preparation on screw pullout resistance and screw insertional torque.
Methods. Three different screws were tested: cancellous lateral mass screws, cortical lateral mass screws, and pedicle screws. Synthetic bone blocks were used as the host material. Each screw group was separated into two subgroups. The first subgroup of screws was inserted into the test material following pilot hole preparation. Pilot holes were prepared; a drill bit diameter size smaller than the core diameter of the screws was used. The second group of screws was inserted into the test material without pilot hole preparation (a 3- or 4-mm hole drilled for entrance site preparation only). The insertional torque was measured as the screw was advanced into the material. The screws were axially extracted from the host material at a constant speed of 2.5 mm/minute. The pullout resistances and insertional torques for the pilot hole and the nonpilot hole groups were then statistically compared.
The authors found that preparation of a pilot hole caused a significant decrease in the insertional torque. The screws inserted without a pilot hole showed greater pullout resistances compared with those inserted following a pilot hole preparation; however, there was no statistically significant difference.
Conclusions. The optimum screw insertion technique may involve drilling a short pilot hole and using a drill bit with a smaller diameter than the screw core diameter to increase bone—screw purchase. This applies to cancellous and cortical lateral mass screws as well as pedicle screws.
Microsurgical anterior cervical foraminotomy (uncinatectomy) for cervical disc herniation
Authors: Taşçioǧlu Al O. , Attar Ayhan , Taşçioǧlu Beliz 
Published: May 2009

✓ The authors present the long-term follow-up results in three cases in which pure lateral disc herniations were surgically treated via an anterior foraminotomy (uncinatectomy) that avoided entering the disc space.
The pertinent anatomical details essential for a safe approach are discussed in light of nine cadaveric neck dissections of every segment between C-1 and C-7. The surgical technique was initially studied in the cadaveric specimens and then applied in patients.
The long-term results (> 2 years) in the first three patients are as good as our short-term results in another eight cases.
Os odontoideum associated with hypertrophic ossiculum terminale
Authors: Sakaida Hiroshi , Waga Shiro , Kojima Tadashi , Kubo Yoshichika , Niwa Shigehiko , Matsubara Toshio 
Published: May 2009

✓ The authors report on the case of a 20-year-old man who presented with a transient tetraparesis. Neuroimaging studies demonstrated atlantoaxial dislocation and ventral compression of the rostral spinal cord caused by a quite rare association of os odontoideum and hypertrophic ossiculum terminale. The patient underwent removal of two free ossicula via a transoral approach and posterior fusion in which an autogenous bone graft was placed.
The majority of cases of os odontoideum are believed to be an acquired form; however, controversy with regard to the congenital causes of os odontoideum remains. One hypothesis is that os odontoideum results from the failure of fusion and the hypertrophy of the proatlas, although considerable confusion surrounds this hypothesis because definitive classification of os odontoideum—to differentiate between similar anomalies—has not been established. This rare coincidence in the current case supports the belief that os odontoideum has a different embryological origin from ossiculum terminale, which is thought to be a proatlantal remnant.
Use of cylindrical titanium mesh and locking plates in anterior cervical fusion
Authors: Das Kaushik , Couldwell William T. , Sava Gerard , Tadonio Rudolph F. 
Published: May 2009

✓ After performing anterior cervical corpectomy or discectomy for cervical spondolytic myelopathy or radiculopathy, iliac crest bone graft and fibular auto- or allograft is often used to achieve arthrodesis in the cervical spine. The purpose of this study was to evaluate the use of a cylindrical titanium mesh and locking plate system as an alternative technique in achieving anterior cervical fusion and maintaining lordosis.
Hospital records and radiographs of 38 patients who underwent anterior cervical discectomies (28 patients) or corpectomies (10 patients) from 1995 to 1997 were reviewed retrospectively. All patients had undergone arthrodesis in which autograft and a cylindrical titanium mesh and anterior locking plate fixation were used after discectomy or corpectomy. There were 20 men and 18 women (mean age 46.1 years; range 34–72 years). Presenting symptoms included radiculopathy (61%), myelopathy (37%), and neck pain (2%). Preoperative and postoperative radiographs were studied, and data were obtained on the following: overall lordosis or kyphosis of the cervical spine, segmental lordosis or kyphosis at each surgically treated level, and evidence of fusion.
In all of the patients in whom lordosis was present preoperatively, lordosis was maintained during the follow-up period. The overall fusion rate was 100%. The average change in overall lordosis or kyphosis related to the fixation devices was 1.2° (range 1–5°); the average segmental change was 2.3° (range 0–5°); and the mean follow up was 16 months (range 12–36 months).
Anterior cervical fusion with cylindrical titanium mesh and cervical locking plate system is an effective method of achieving arthrodesis and maintaining alignment in the cervical spine. The construct may provide additional load-sharing function, and it avoids the use of cadaveric bone or the need for harvesting tricortical iliac crest autograft.
Can airway complications following multilevel anterior cervical surgery be avoided?
Authors: Epstein Nancy E. , Hollingsworth Renee , Nardi Dominic , Singer Johnathan 
Published: May 2009

Object. The authors conducted a study to determine how to avoid emergency postoperative reintubation and its associated morbidity in patients who have undergone multilevel anterior—posterior cervical spine surgery.
Methods. In a group effort between the departments of anesthesia and neurosurgery, a protocol was developed to avoid having to reintubate patients postoperatively. As a preventative measure, patients remained intubated overnight; on the 1st postoperative day or thereafter, based on direct fiberoptic visualization of reactive tracheal swelling, an anesthesiologist extubated the patients. Fifty-eight patients underwent multilevel anterior corpectomy with fusion (ACF; with 41 receiving plates and 17 not receiving plates), posterior wiring and fusion (PWF), and application of a halo. On average, ACF involved three levels, whereas PWF included 6.5 levels. Surgery typically lasted 10 hours, and an average 2.6 U of blood was required.
Forty patients were successfully extubated on the 1st, five on the 2nd, three on the 3rd, two on the 4th, two on the 5th, and three on the 7th postoperative day. Three elective tracheostomies were performed on the 7th postoperative day. Risk factors associated with delayed extubation or tracheostomy in 18 patients included: operative time longer than 10 hours (12 patients), obesity greater than 220 lbs (12 patients), transfusion of more than 4 U of blood (10 patients), ACF reoperations (nine patients), ACF including C-2 (seven patients), four-level ACF (five patients), and asthma (five patients). In the only case in which emergency reintubation was required, three risk factors were present.
Conclusions. Emergency reintubation following anterior—posterior cervical surgery and fusion can be avoided by maintaining intubation overnight and subsequently having an anesthesiologist remove the tube after healing is fiberoptically confirmed. Familiarity with major risk factors contributing to airway compromise, combined with this protocol, should minimize the significant morbidity associated with reintubation following multilevel anterior—posterior cervical fusion.
Clinical and radiological correlates of severity and surgery-related outcome in cervical spondylosis
Authors: Singh Anoushka , Crockard H. Alan , Platts Andrew , Stevens John 
Published: May 2009

Object. The aim of this study was to determine if radiological features could be used to predict outcome in patients with cervical spondylotic myelopathy (CSM).
Methods. The authors studied 69 patients consecutively referred to The National Hospital, Queen Square, for decompressive surgery. Data obtained from preoperative cervical spine magnetic resonance (MR) imaging studies were each analyzed on two separate occasions by two blinded radiologists. The parameters determined were signal change and the presence and severity of compression. Clinical outcome was determined by pre- and postoperative timed walks, as well as by evaluation of myelopathy disability index scores, Ranawat classification, and Nurick grades.
There was good inter- and intraobserver reliability for determination of radiological data. A significant relationship was found between MR imaging signal change and surgery-related outcome, as reflected by improvement in walking parameters; however, this was confounded by the fact that signal change also related to preoperative walking parameters, and those patients for whom preoperative walking function was worse experienced greater functional improvement in walking postoperatively. The relationships between ambulatory-related data and severity or extent of spinal cord compression were less marked.
Conclusions. Cervical cord compression and intrinsic MR imaging signal change correlate with clinical severity, and, in this population, the presence of signal change was correlated with better surgery-related outcome. However, confounding factors and the lack of strong correlation indicate that these radiological measurements are insufficient to be used as a reliable tool for predicting surgery-related benefits in individual patients.
Presence and significance of CD-95 (Fas/APO1) expression after spinal cord injury
Authors: Zurita Mercedes , Vaquero Jesús , Zurita Isabel 
Published: May 2009

Object. A glycoprotein, CD95 (Fas/APO1) is widely considered to be implicated in the development of apoptosis in a number of tissues. Based on the hypothesis that apoptosis is related to cell death after spinal cord injury (SCI), the authors studied the presence and distribution of CD95 (Fas/APO1)-positive cells in injured spinal cord tissue for the purpose of determining the significance of this protein during the early phases of SCI.
Methods. The presence and distribution of cells showing positive immunostaining for CD95 (Fas/APO1) were studied 1, 4, 8, 24, 48, and 72 hours and 1, 2, and 4 weeks after induction of experimental SCI in rats. Studies were conducted using a monoclonal antibody to the CD95 (Fas/APO1) protein. Positivity for CD95 (Fas/APO1) was observed in apoptotic cells, mainly in the gray matter, 1 hour after trauma, and the number of immunostained cells increased for the first 8 hours, at which time the protein was expressed in both gray and white matter. From 24 to 72 hours postinjury, the number of immunostained cells decreased in the gray matter, but increased in the white matter. From then on, there were fewer CD95 (Fas/APO1)-positive cells, but some cells in the white matter still exhibited positive immunostaining 1 and 2 weeks after injury. At 4 weeks, there remained no CD95 (Fas/APO1)-positive cells in injured spinal cord.
Conclusions. These findings indicate that CD95 (Fas/APO1) is expressed after SCI, suggesting a role for this protein in the development of apoptosis after trauma and the possibility of a new therapeutic approach to SCI based on blocking the CD95 (Fas/APO1) system.
Cervical spinal motion during intubation: efficacy of stabilization maneuvers in the setting of complete segmental instability
Authors: Lennarson Peter J. , Smith Darin W. , Sawin Paul D. , Todd Michael M. , Sato Yutaka , Traynelis Vincent C. 
Published: May 2009

Object. The purpose of this study was to characterize and compare segmental cervical motion during orotracheal intubation in cadavers with and without a complete subaxial injury, as well as to examine the efficacy of commonly used stabilization techniques in limiting that motion.
Methods. Intubation procedures were performed in 10 fresh human cadavers in which cervical spines were intact and following the creation of a complete C4–5 ligamentous injury. Movement of the cervical spine during direct laryngoscopy and intubation was recorded using video fluoroscopy and examined under the following conditions: 1) without stabilization; 2) with manual in-line cervical immobilization; and 3) with Gardner—Wells traction. Subsequently, segmental angular rotation, subluxation, and distraction at the injured C4–5 level were measured from digitized frames of the recorded video fluoroscopy.
Conclusions: After complete C4–5 destabilization, the effects of attempted stabilization on distraction, angulation, and subluxation were analyzed. Immobilization effectively eliminated distraction, and diminished angulation, but increased subluxation. Traction significantly increased distraction, but decreased angular rotation and effectively eliminated subluxation. Orotracheal intubation without stabilization had intermediate results, causing less distraction than traction, less subluxation than immobilization, but increased angulation compared with either intervention.
These results are discussed in terms of both statistical and clinical significance and recommendations are made.
En bloc removal of the lower lumbar vertebral body for chordoma
Authors: Bosma Jark J. D. , Pigott Timothy J. D. , Pennie Bruce H. , Jaffray David C. 
Published: May 2009

✓ En bloc removal of the lower lumbar vertebral bodies (VBs) is a major surgical challenge. The authors describe the surgical technique used in two patients who presented with chordoma confined to the L-5 and L-4 VB, respectively. These tumors were diagnosed using magnetic resonance (MR) imaging during investigation for back pain.
Both patients underwent a combined (two-stage) anterior—posterior approach. In the first case the posterior stage of the procedure was followed by an anterior retroperitoneal approach, and in the second case a lateral retroperitoneal approach was used.
Complete en bloc excision of the tumor was achieved in each case, even though in the second case the VB fractured when it was mobilized. The correlation between the MR imaging findings and surgical specimens was remarkable.
The authors conclude that en bloc resection is feasible in these cases. Because mobilization of the VB is more difficult in the lateral approach, the authors favor the anterior retroperitoneal approach.
The authors anticipate the need for such procedures to increase with the widespread use of MR imaging, which demonstrates the extent of these tumors with remarkable accuracy.
Use of a guide device to place pedicle screws in the thoracic spine: a cadaveric study
Authors: Jang Jee Soo , Lee Won Bok , Yuan Hansen A. 
Published: May 2009

✓ In this cadaveric study, the safety and accuracy of a specially designed guide device for the placement of thoracic pedicle screws was investigated in a normal anatomical situation.
Five embalmed human cadaveric thoracic spines (T1–12) were used for the study of transpedicular screw placement in the thoracic spine. Overall 120 screws were placed at all thoracic levels. The screws were inserted bilaterally in the thoracic pedicles by using a specially designed guide device. No radiographs or other imaging studies were obtained. Following screw placement, computerized tomography scans were performed to evaluate the accuracy of the pedicle screw positioning.
Seven (5.8%) of the screws penetrated the pedicle wall or the vertebral body (VB) cortex. Two screws (1.7%) penetrated the medial wall of the pedicle. Two screws (1.7%) penetrated the lateral wall of the pedicle, and one screw (0.8%) penetrated the lateral wall of the pedicle and the anterior VB cortex simultaneously. Two screws (1.7%) penetrated the anterior VB cortex.
Compared with the results of other studies, the findings here indicate that using this device to guide the placement of thoracic pedicle screws can significantly reduce the incidence of pedicle penetration, particularly in the medial wall.
Threaded cortical bone dowels for lumbar interbody fusion: over 1-year mean follow up in 28 patients
Authors: Barnes Bryan , Rodts Gerald E. , McLaughlin Mark R. , Haid Regis W. 
Published: May 2009

Object. The authors retrospectively reviewed a series of 35 patients with mechanical low-back or one- to two-level discogenic pain; the patients underwent lumbar interbody fusion in which threaded cortical bone dowels (TCBDs) were placed to treat degenerative disc disease. The purpose of the study was to delineate fusion rates and outcome data in this series of patients.
Methods. The series was composed of 18 women and 17 men whose mean age was 46 years (range 17–76 years). There were nine active cigarette smokers. All patients presented with symptoms consistent with mechanical low-back or discogenic pain, and magnetic resonance imaging revealed degenerative changes related to disc collapse at one or two vertebral levels. For placement of the TCBDs, 23 patients underwent posterior lumbar interbody fusion (PLIF), whereas 12 patients underwent anterior lumbar interbody fusion (ALIF). In all except one patient undergoing PLIF, pedicle screw and rod constructs were used without posterolateral fusion. In all patients undergoing ALIF except one, TCBDs were used as stand-alone devices without supplemental fixation. At follow up the success of fusion was determined by static lumbar radiography and/or computerized tomography scanning. The degree of lumbar lordosis at the diseased level was measured immediately postoperatively and compared with that documented on follow-up radiological studies. Outcomes were assessed using a modified Prolo Scale. Excellent and good outcomes were considered satisfactory, and fair or poor outcomes were considered unsatisfactory.
In 28 patients (eight ALIF and 20 PLIF) radiological and clinical follow-up data were considered adequate. The mean follow-up duration was 12.3 months. Overall satisfactory outcome was 60%; 70% satisfactory outcome was noted in PLIF patients and 38% in ALIF patients. Osseous fusion was present in 95% of the patients in the PLIF group and in 13% of those in the ALIF group. Complications included one L-5 nerve root injury and two postoperative wound infections, all in patients who underwent PLIF; in an ALIF patient lateral breakout of one implant occurred at 8 months postoperatively.
Conclusions. Analysis of the mean 12.3 month follow-up data indicates that there is a dramatically higher fusion rate in PLIF compared with ALIF procedures when TCBDs are used. The authors believe that it is important to note that in all the PLIF procedures except one, supplemental pedicle screw/rod constructs were used, whereas in ALIF procedures no supplemental fixation was performed. The results thus suggest that TCBDs are best used in PLIF in conjunction with pedicle screw and rod constructs.
Adjacent-segment morbidity after Graf ligamentoplasty compared with posterolateral lumbar fusion
Authors: Kanayama Masahiro , Hashimoto Tomoyuki , Shigenobu Keiichi , Harada Masahito , Oha Fumihiro , Ohkoshi Yasumitsu , Tada Hiroshi , Yamamoto Kazuki , Yamane Shigeru 
Published: May 2009

Object. Of concern to spine surgeons are accelerated degenerative changes of motion segments located above and below where spinal fusion has been performed. Graf artificial ligament stabilization has been developed to avoid the adverse effect of spinal fusion. The object of this study was to assess the adjacent-segment morbidity of Graf ligamentoplasty compared with posterolateral fusion (PF) in which instrumentation was used.
Methods. Data obtained in 45 patients who underwent L4–5 Graf ligamentoplasty (18 patients) or PF with instrumentation (27 patients) were reviewed retrospectively. The minimum follow-up period was 5 years. In the PF group a solid fusion rate of 92.6% was achieved. Radiographic evaluation included assessment of lumbar sagittal alignment, range of motion (ROM), and adjacent-disc degeneration. Adjacent-segment morbidity was clinically assessed by determining the reoperation rate.
Graf ligamentoplasty maintained regional lordosis and flexibility (13° in L4–5 lordosis; 4.4° in L4–5 ROM). Although there was no difference in preoperative adjacent-disc condition between the two groups, radiographic evidence of adjacent-disc deterioration was observed more frequently in patients in the PF group than the Graf group (25% and 6% at L1–2; 38% and 6% at L2–3; 38% and 18% at L3–4; and 43% and 18% at L5—sacrum, respectively). One case in the Graf group (5.6%) and five cases in the PF group (18.5%) required additional surgeries for adjacent-segment lesions.
Conclusions. Graf ligamentoplasty cannot completely replace spinal fusion. In a well-selected group of patients, however, it was shown to maintain lumbar mobility and sagittal alignment, and it decreased the risk of adjacent-segment deterioration compared with PF with instrumentation.
Management of complex pediatric and adolescent spinal deformity
Authors: Wiggins Gregory C. , Rauzzino Michael J. , Bartkowski Henry M. , Nockels Russ P. , Shaffrey Christopher I. 
Published: May 2009

Object. The authors sought to analyze prospectively the outcome of surgery for complex spinal deformity in the pediatric and young adult populations.
Methods. The authors evaluate all pediatric and adolescent patients undergoing operative correction of complex spinal deformity from December 1997 through July 1999. No patient was lost to follow-up review (average 21.1 months). There were 27 consecutive pediatric and adolescent patients (3–20 years of age) who underwent 32 operations. Diagnoses included scoliosis (18 idiopathic, five nonidiopathic) and four severe kyphoscoliosis. Operative correction and arthrodesis were achieved via 21 posterior approaches (Cotrel-Dubousset-Horizon), seven anterior approaches (Isola or Kaneda Scoliosis System), and two combined approaches. Operative time averaged 358 minutes (range 115–620 minutes). Blood loss averaged 807 ml (range 100–2000 ml). Levels treated averaged 9.1 (range three–16 levels). There was a 54% average Cobb angle correction (range 6–82%). No case was complicated by the patient's neurological deterioration, loss of somatosensory evoked potential monitoring, cardiopulmonary disease, donor-site complication, or wound breakdown. There was one case of hook failure and one progression of deformity beyond the site of surgical instrumentation that required reoperation. There were 10 minor complications that did not significantly affect patient outcome. No patient received undirected banked blood products. There was a significant improvement in cosmesis, and no patient experienced continued pain postoperatively. All patients have been able to return to their preoperative activities.
Conclusions. Compared with other major neurosurgical operations, segmental instrumentation for pediatric and adolescent spinal deformity is a safe procedure with minimal morbidity and there is a low risk of needing to use allogeneic blood products.