bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operative versus nonoperative management of acute odontoid Type II fractures: a meta-analysis
Authors: Nourbakhsh Ali , Shi Runhua , Vannemreddy Prasad , Nanda Anil 
Published: February 2011

Object
The purpose of this study was to evaluate the feasibility of the criteria described in the literature as the indications for surgery for acute Type II odontoid fractures.

Methods
The authors searched the PubMed database for studies in which the fusion rate of acute Type II odontoid fractures following external immobilization (halo vest or collar) or surgery (posterior C1–2 fusion or anterior screw fixation) was reported. The only studies included reported the fusion rate for either 1) groups of patients whose age was either more or less than a certain age range (45–55 years); or 2) groups of patients with a fracture displacement of either more or less than a certain odontoid fracture displacement (4–6 mm) or the direction of displacement (see Methods section of text for more details). A meta-analysis in which the random effect model was used was conducted to analyze the data.

Results
There was a statistically significantly higher fusion rate for operative management compared with external immobilization (85 vs 60%, p = 0.01) for the patients > 45–55 years. However, the overall fusion rate was > 80% for the patients whose age was < 45–55 years, regardless of treatment modality, and no significant differences were observed between surgically and nonsurgically treated patients (89 and 81%, respectively; p = 0.29). The result of operation (overall fusion rate 89%) was superior to external immobilization (44%) when the fracture was posteriorly displaced (p < 0.001), but for anteriorly displaced fractures, the results of operative and nonoperative management were identical (p = 0.15). The overall fusion rate of operative management of both anteriorly and posteriorly displaced fractures proved to be > 85%, and no statistically significant difference was observed (p = 0.50). For all degrees of displacement (either > or < 4–6 mm) the operation proved to provide significantly better results than conservative treatment. The fusion rate of conservatively treated fractures with < 4–6 mm displacement was significantly better than in fractures with > 4–6 mm displacement (76 vs 41%, p = 0.002).

Conclusions
Operative treatment (posterior C1–2 fixation or anterior screw fixation) provides a better fusion rate than external immobilization for acute odontoid Type II fractures, although in certain situations, such as anterior displacement of the fracture and for younger (< 45–55 years of age) patients, conservative management (halo vest or collar immobilization) can be as effective as surgery. Operative management is recommended in older patients, in cases of posterior displacement of the fracture, and when there is displacement of > 4–6 mm.
Accuracy of pedicle screw placement in the lumbosacral spine using conventional technique: computed tomography postoperative assessment in 102 consecutive patients
Authors: Amato Vincenzo , Giannachi Luigi , Irace Claudio , Corona Claudio 
Published: February 2011

ObjectThe goal of this study was to determine the incidence of screw misplacement and complications in a group of 102 patients who underwent transpedicle screw fixation in the lumbosacral spine with conventional open technique and intraoperative fluoroscopy. The results are compared with published data.MethodsCases involving 102 consecutive patients (424 inserted screws) were reviewed. Surgery was performed in all cases by the same surgeon's team, using the same implant, and all results were assessed by means of a specific CT protocol. The screw position was assessed by the authors and an independent observer. Screw position was classified as correct when the screw was completely surrounded by the pedicle cortex, as “cortical encroachment” (questionable violation) if the pedicle cortex could not be visualized, and as “frank penetration” when the screw was outside the pedicular boundaries. Frank penetration was further subdivided as minor (when the edge of the screw thread was up to 2.0 mm outside the pedicle cortex), moderate (2.1–4 mm), and severe (> 4 mm). The incidence of intra- and postoperative complications not related to screw position as well as hardware failures were also registered, with a minimum follow-up duration of 8 months.ResultsThe rate of frank pedicle screw misplacement was 5%. The rate of minimal or questionable pedicle wall violation was 2.8%. Among the frank misplacements, 6 were classified as minor, 12 as moderate, and 3 as severe penetration. Two patients (2%) had radicular pain and neurological deficits (inferomedial and inferolateral minor misplacement at L-4 and L-5, respectively), and 5 patients (4.9%) complained only of radicular pain. At the follow-up examination all patients had completely recovered their neurological function and radicular pain was resolved in all cases. The complications not related to screw malposition were 2 pedicle fractures (2% of patients), 1 nerve root injury (1%), and 1 dural laceration (1%). Five patients (4.8%) had postoperative anemia and required transfusions. Superficial or deep wound infection was noted in 3 patients (2.9%). Late hardware failure occurred in 2 patients (2%). One patient developed adjacent segmental instability and required additional surgery to extend the fusion.ConclusionsOur rates of screw misplacement and complications compare favorably with the lowest rates of the series in which conventional technique was used and are close to the rates reported for image-guided methods. The risk of malpositioning may be reduced with careful preoperative surgical planning, accurate knowledge of the spinal anatomy, surgical experience, and correct indication for conventional surgery. The conventional technique still remains a practical, safe, and effective surgical method for lumbosacral fixation.
Intradiscal electrothermal therapy for symptomatic internal disc disruption: 24-month results and predictors of clinical success
Authors: Assietti Roberto , Morosi Mario , Block Jon E. 
Published: February 2011

ObjectDegeneration of the intervertebral disc can be the source of severe low-back pain. Intradiscal electrothermal therapy (IDET) is a minimally invasive treatment option for patients with symptomatic internal disc disruption unresponsive to conservative medical care. This study was undertaken in the neurosurgical setting to evaluate 24-month pain and functional outcomes and predictors of clinical success in patients with discogenic back pain treated with IDET.MethodsUsing MR imaging and discography findings, 50 patients with lumbar discogenic pain were identified, underwent IDET treatment, and were followed up for 24 months. Outcomes included assessments of back pain severity based on an 11-point numeric scale and back function based on the Oswestry Disability Index. The Prolo scale was applied to determine economic and functional status at 24 months.ResultsThere was an average 68 and 66% improvement in back pain and function, respectively, between pretreatment and 24 months after treatment (p < 0.0001 for both comparisons). A maximum score of 5 on the Prolo scale for economic and functional status was achieved in 63 and 22% of patients, respectively. The global clinical success rate was 78% (39 of 50 patients) based on no reoperations at the affected level due to persistent symptoms, with a ≥ 2-point improvement in pain severity and a ≥ 15-point improvement in back function. Predictors of 24-month clinical success included discographic concordance (p < 0.0001), a high-intensity zone on MR imaging (p = 0.0003), low Pfirrmann grade (p = 0.0002), and more extensive anulus coverage (p < 0.0001). There were no procedure-related adverse events.ConclusionsThe findings of this study suggest that durable clinical improvements can be realized after IDET in highly select surgical candidates with mild disc degeneration, confirmatory imaging evidence of anular disruption, and highly concordant pain provocation on low-pressure discography.
Biomechanical study of the effect of degree of static compression of the spinal cord in ossification of the posterior longitudinal ligament
Authors: Kato Yoshihiko , Kanchiku Tsukasa , Imajo Yasuaki , Kimura Kotaro , Ichihara Kazuhiko , Kawano Syunichi , Hamanaka Daisuke , Yaji Kentaro , Taguchi Toshihiko 
Published: February 2011

Object
The authors evaluated the biomechanical effect of 3 different degrees of static compression in a model of the spinal cord in order to investigate the effect of cord compression in patients with ossification of the posterior longitudinal ligament (OPLL).

Methods
A 3D finite element spinal cord model consisting of gray matter, white matter, and pia mater was established. As a simulation of OPLL-induced compression, a rigid plate compressed the anterior surface of the cord. The degrees of compression were 10, 20, and 40% of the anteroposterior (AP) diameter of the cord. The cord was supported from behind by the rigid body along its the posterior border, simulating the lamina. Stress distributions inside of the cord were evaluated.

Results
The stresses on the cord were very low under 10% compression. At 20% compression, the stresses on the cord increased very slightly. At 40% compression, the stresses on the cord became much higher than with 20% compression, and high stress distributions were observed in gray matter and the lateral and posterior funiculus. The stresses on the compressed layers were much higher than those on the uncompressed layer.

Conclusions
The stress distributions at 10 and 20% compression of the AP diameter of the spinal cord were very low. The stress distribution at 40% compression was much higher. The authors conclude that a critical point may exist between 20 and 40% compression of the AP diameter of the cord such that when the degree of the compression exceeds this point, the stress distribution becomes much higher, and that this may contribute to myelopathy.
Cystic deterioration of the C1–2 articulation: clinical implications and treatment outcomes
Authors: Van Gompel Jamie J. , Morris Jonathan M. , Kasperbauer Jan L. , Graner Darlene E. , Krauss William E. 
Published: February 2011

Object
Synovial cysts of the cervical spine are rare. Further, synovial cysts of the C1–2 articulation, or retroodontoid cysts, are very rare, with fewer than 20 cases reported overall. The authors report on a single-institution series of 10 patients with C1–2 retroodontoid synovial cysts.

Methods
The charts of 10 patients with pathologically confirmed synovial cysts following resection between January 1998 and June 2009 were reviewed. The clinical presentation, radiographic findings, surgical management, and pre- and postoperative functional levels (reported as a modified Rankin outcome) are reported.

Results
All 10 patients underwent attempts at complete resection of the synovial cyst; none of the lesions were simply aspirated. All 4 patients with an initial recommendation of observation alone ultimately underwent surgery because of their swift neurological deterioration. The mean age at surgery was 75.4 ± 4.6 years (range 54–81 years). The mean presenting cyst volume was 4.6 ± 1.7 cm3. Nine of 10 patients underwent transoral resection of the cyst with posterior fusion. Six of the 10 patients underwent additional posterior laminectomy for decompression. The hospital length of stay varied from 2 to 45 days, with a mean of 19 ± 7 days. All patients undergoing transoral decompression had varying degrees of difficulty with postoperative dysphagia, diagnosed using videofluoroscopy. All patients improved in their modified Rankin Scale score after surgical intervention with a mean follow-up of 42 months (95% CI 12–72 months).

Conclusions
Synovial cysts of the atlantoaxial joint are rare. They occur in older patients in whom clinical deterioration is likely to occur. In most cases, these cysts can be diagnosed preoperatively. Transoral decompression with posterior fusion is an effective treatment for C1–2 degenerative cysts and can be accomplished with few complications. However, the ideal treatment for these lesions remains unknown.
Can surgery improve neurological function in penetrating spinal injury? A review of the military and civilian literature and treatment recommendations for military neurosurgeons
Authors: Klimo Paul , Ragel Brian T. , Rosner Michael , Gluf Wayne , McCafferty Randall 
Published: February 2011

Object
Penetrating spinal injury (PSI), although an infrequent injury in the civilian population, is not an infrequent injury in military conflicts. Throughout military history, the role of surgery in the treatment of PSI has been controversial. The US is currently involved in 2 military campaigns, the hallmark of both being the widespread use of various explosive devices. The authors reviewed the evidence for or against the use of decompressive laminectomy to treat PSI to provide a triservice (US Army, Navy, and Air Force) consensus and treatment recommendations for military neurosurgeons and spine surgeons.

Methods
A US National Library of Medicine PubMed database search that identified all literature dealing with acute management of PSI from military conflicts and civilian urban trauma centers in the post–Vietnam War period was undertaken.

Results
Nineteen retrospective case series (11 military and 8 civilian) met the study criteria. Eleven military articles covered a 20-year time span that included 782 patients who suffered either gunshot or blast-related projectile wounds. Four papers included sufficient data that analyzed the effectiveness of surgery compared with nonoperative management, 6 papers concluded that surgery was of no benefit, 2 papers indicated that surgery did have a role, and 3 papers made no comment. Eight civilian articles covered a 9-year time span that included 653 patients with spinal gunshot wounds. Two articles lacked any comparative data because of treatment bias. Two papers concluded that decompressive laminectomy had a beneficial role, 1 paper favored the removal of intracanal bullets between T-12 and L-4, and 5 papers indicated that surgery was of no benefit.

Conclusions
Based on the authors' military and civilian PubMed literature search, most of the evidence suggests that decompressive laminectomy does not improve neurological function in patients with PSI. However, there are serious methodological shortcomings in both literature groups. For this and other reasons, neurosurgeons from the US Air Force, Army, and Navy collectively believe that decompression should still be considered for any patient with an incomplete neurological injury and continued spinal canal compromise, ideally within 24–48 hours of injury; the patient should be stabilized concurrently if it is believed that the spinal injury is unstable. The authors recognize the highly controversial nature of this topic and hope that this literature review and the proposed treatment recommendations will be a valuable resource for deployed neurosurgeons. Ultimately, the deployed neurosurgeon must make the final treatment decision based on his or her opinion of the literature, individual abilities, and facility resources available.
Wartime decompressive craniectomy: technique and lessons learned
Authors: Ragel Brian T. , Klimo Paul , Martin Jonathan E. , Teff Richard J. , Bakken Hans E. , Armonda Rocco A. 
Published: February 2011

Object
Decompressive craniectomy (DC) with dural expansion is a life-saving neurosurgical procedure performed for recalcitrant intracranial hypertension due to trauma, stroke, and a multitude of other etiologies. Illustratively, we describe technique and lessons learned using DC for battlefield trauma.

Methods
Neurosurgical operative logs from service (October 2007 to September 2009) in Afghanistan that detail DC cases for trauma were analyzed. Illustrative examples of frontotemporoparietal and bifrontal DC that depict battlefield experience performing these procedures are presented with attention drawn to the L.G. Kempe hemispherectomy incision, brainstem decompression techniques, and dural onlay substitutes.

Results
Ninety craniotomies were performed for trauma over the time period analyzed. Of these, 28 (31%) were DCs. Of the 28 DCs, 24 (86%) were frontotemporoparietal DCs, 7 (25%) were bifrontal DCs, and 2 (7%) were suboccipital DCs. Decompressive craniectomies were performed for 19 penetrating head injuries (13 gunshot wounds and 6 explosions) and 9 severe closed head injuries (6 war-related explosions and 3 others).

Conclusions
Thirty-one percent of craniotomies performed for trauma were DCs. Battlefield neurosurgeons use DC to allow for safe transfer of neurologically ill patients to tertiary military hospitals, which can be located 8–18 hours from a war zone. The authors recommend the L.G. Kempe incision for blood supply preservation, large craniectomies to prevent brain strangulation over bone edges, minimal brain debridement, adequate brainstem decompression, and dural onlay substitutes for dural closure.
Analysis of load sharing on uncovertebral and facet joints at the C5–6 level with implantation of the Bryan, Prestige LP, or ProDisc-C cervical disc prosthesis: an in vivo image-based finite element study
Authors: Kang Heesuk , Park Paul , La Marca Frank , Hollister Scott J. , Lin Chia-Ying 
Published: February 2011

Object
The goal of this study was to evaluate and compare load sharing of the facet and uncovertebral joints after total cervical disc arthroplasty using 3 different implant designs.

Methods
Three-dimensional voxel finite element models were built for the C5–6 spine unit based on CT images acquired from a candidate patient for cervical disc arthroplasty. Models of facet and uncovertebral joints were added and artificial discs were placed in the intervertebral disc space. Finite element analyses were conducted under normal physiological loads for flexion, extension, and lateral bending to evaluate von Mises stresses and strain energy density (SED) levels at the joints.

Results
The Bryan disc imposed the greatest average stress and SED levels at facet and uncovertebral joints with flexion-extension and lateral bending, while the ProDisc-C and Prestige LP discs transferred less load due to their rigid cores. However, all artificial discs showed increased loads at the joints in lateral bending, which may be attributed to direct impinging contact force.

Conclusions
In unconstrained/semiconstrained prostheses with different core rigidity, the shared loads at the joints differ, and greater flexibility may result in greater joint loads. With respect to the 3 artificial discs studied, load sharing of the Bryan disc was highest and was closest to normal load sharing with the facet and uncovertebral joints. The Prestige LP and ProDisc-C carried more load through their rigid core, resulting in decreased load transmission to the facet and uncovertebral joints.
Effect of arthroplasty design on cervical spine kinematics: analysis of the Bryan Disc, ProDisc-C, and Synergy Disc
Authors: Lazaro Bruno C. R. , Yucesoy Kemal , Yuksel Kasim Z. , Kowalczyk Izabela , Rabin Doron , Fink Marie , Duggal Neil 
Published: February 2011

Object
Cervical total disc replacement has emerged as a surgical option to preserve motion and potentially avoid adjacent-segment disease after anterior cervical discectomy and fusion. Recently, much attention has been directed at the ability of a given device to maintain and/or restore normal segmental alignment. Nonphysiological disc and segmental angulation could result in increased stresses transmitted to the facet joints and posterior elements, conflicting with the essence of arthroplasty and potentially leading to adjacent-segment disease. The goal of this study was to contrast device alignment and segmental kinematics provided by 3 different cervical disc prostheses.

Methods
Sixty patients were retrospectively analyzed and divided into 3 groups receiving the Bryan, ProDisc-C, or Synergy disc. Only single-level arthroplasty cases were included in the study. Lateral dynamic radiographs of the cervical spine were analyzed using quantitative motion analysis software (Medical Metrics, Inc.) to analyze the kinematics at the index level both preoperatively and postoperatively. Several parameters were noted, including range of motion, disc angles, shell angles, anterior and posterior disc heights, translation, and center of rotation. Preoperative and postoperative data were compared using the Student t-test with a significance level of p < 0.05.

Results
Postoperatively, all 3 disc groups maintained adequate range of motion at the implanted level. With respect to the shell angles, the Synergy disc demonstrated the least variability, maintaining 6° lordotic configuration between the device endplates. In the Bryan disc group, significant shell kyphosis developed postoperatively (p < 0.0001). Both ProDisc-C and Synergy discs significantly increased anterior and posterior disc heights (p < 0.0001). The Bryan and Synergy discs maintained the natural center of rotation, whereas significant anterior shift occurred with ProDisc-C.

Conclusions
The goal for motion preservation at the implanted level was achieved using all 3 devices. The Synergy disc was unique in its ability to alter device angulation by 6°. The Bryan disc demonstrated device endplate kyphosis. Both the Synergy disc and ProDisc-C increased disc space height.
Biomechanical evaluation of posterior thoracic transpedicular discectomy
Authors: Deniz Fatih Ersay , Brasiliense Leonardo B. C. , Lazaro Bruno C. R. , Reyes Phillip M. , Sawa Anna G. U. , Sonntag Volker K. H. , Crawford Neil R. 
Published: February 2011

Object
The authors investigated the biomechanical properties of transpedicular discectomy in the thoracic spine and compared the effects on spinal stability of a partial and total facetectomy.

Methods
Human thoracic specimens were tested while intact, after a transpedicular discectomy with partial facetectomy, and after an additional total facetectomy was incorporated. Nonconstraining pure moments were applied under load control (maximum 7.5 Nm) to induce flexion, extension, lateral bending, and axial rotation while spinal motion was measured at T8–9 optoelectronically. The range of motion (ROM) and lax zone were determined in each specimen and compared among conditions.

Results
Transpedicular discectomy with and without a total facetectomy significantly increased the ROM and lax zone in all directions of loading compared with the intact spine (p < 0.008). The segmental increase in ROM observed with the transpedicular discectomy was 25%. The additional total facetectomy created an insignificant 3% further increase in ROM compared with medial facetectomy (p > 0.2).

Conclusions
Transpedicular discectomy can be performed in the thoracic spine with a modest decrease in stability expected. Because the biomechanical behavior of a total facetectomy is equivalent to that of a medial facetectomy, the additional facet removal may be incorporated without further biomechanical consequences.