bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of automatic retractors on the esophagus during anterior cervical surgery: an experimental in vivo study in a sheep model
Authors: Çavuşoğlu Halit , Tuncer Cengiz , Tanik Canan , Mutlu Zihni , Zengin Ebruhan , Karabağli Murat , Aydın Yunus 
Published: February 2011

Object
Postoperative dysphagia is a well-recognized complication of the anterior surgical approach to the cervical spine. However, its incidence and etiology remain unknown. The aim of this study was to investigate the impact of automatic retractor use on the esophagus and to describe the related pathological changes that might occur during cervical spine surgery.

Methods
A single-level cervical discectomy was performed via an anterior approach in 16 skeletally mature female sheep. Continuous retraction was applied with an automatic retractor system during surgery. The sheep model was chosen because of anatomical similarities to the human esophagus. The esophageal tract in every animal was examined using contrast radiographic examination. Eight animals were killed 3 days after the operation (Group 1). The remaining sheep were killed 4 weeks after the operation (Group 2). The esophagi were removed for histopathological study, which was performed using H & E and Masson trichrome staining. The changes in esophageal innervation were examined with nicotinamide adenine dinucleotide diphosphate–diaphorase histochemical staining.

Results
Only 1 animal (a Group 1 sheep) demonstrated any postoperative radiographic abnormality. In Group 1 sheep, histopathological study of the esophagi at the treated level revealed edema between the muscular fibers in the outer longitudinal and inner circular layers of the muscularis propria. At some points, obvious signs of vascular congestion, vascular damage, and inflammation were observed. In the Group 2 animals, there was mild-to-moderate fibrosis extending from the outer surface of the esophagus to the longitudinal layers of the muscularis propria in the area to which retraction had been applied. Enzyme-histochemical staining revealed the presence of normal myenteric plexus and ganglion cells, and nitrergic innervation in all parts of the esophagus wall.

Conclusions
The results of this study demonstrate that direct pressure induced by the medial retractor blade on the esophagus wall leads to local injury. Postoperative dysphagia in human patients who have undergone anterior cervical spine surgery could be a clinical manifestation of this phenomenon.
Morphological changes of the multifidus muscle in patients with symptomatic lumbar disc herniation
Authors: Franke Jörg , Hesse Thomas , Tournier Clement , Schuberth Walter , Mawrin Christian , LeHuec Jean Carles , Grasshoff Henning 
Published: February 2011

Object
Lumbar disc herniations are associated with segmental muscle alterations of the ipsilateral segmental multifidus muscle. The aim of the present study was a histopathological analysis of the myopathological changes of the multifidus muscle and correlation with the duration of radicular symptoms.

Methods
Multifidus muscle biopsies were performed in 20 patients during discectomy. Specimens were obtained from the area of the multifidus muscle innervated by the nerve from the level of the affected disc. Histopathological findings were classified according as neurogenic tissue syndrome and nonspecific myopathological syndrome, and these results were correlated with the duration of radicular symptoms.

Results
Results of multifidus muscle biopsies were classified as neurogenic tissue syndrome in 12 patients and as nonspecific myopathological syndrome in 8. The mean (± SD) duration of radicular symptoms was 10.75 ± 7.9 months in patients with neurogenic tissue syndrome and 4.37 ± 3.9 months in patients with a nonspecific myopathological syndrome. There was a positive correlation between group assignment and symptom duration (correlation coefficient 0.457, p = 0.043).

Conclusions
A long duration of radicular symptoms is associated with a neurogenic tissue syndrome, whereas a nonspecific myopathological tissue syndrome is seen in patients with shorter duration of symptoms. This suggests that patients with long duration of radicular symptoms originating from a lumbar disc herniation have an increased risk for neurogenic muscular changes, and that consideration should be given to an earlier surgical intervention.
Effective lordosis: analysis of sagittal spinal canal alignment in cervical spondylotic myelopathy
Authors: Gwinn David E. , Iannotti Christopher A. , Benzel Edward C. , Steinmetz Michael P. 
Published: February 2011

Object
Analysis of cervical sagittal deformity in patients with cervical spondylotic myelopathy (CSM) requires a thorough clinical and radiographic evaluation to select the most appropriate surgical approach. Angular radiographic measurements, which are commonly used to define sagittal deformity, may not be the most appropriate to use for surgical planning. The authors present a simple straight-line method to measure effective spinal canal lordosis and analyze its reliability. Furthermore, comparisons of this measurement to traditional angular measurements of sagittal cervical alignment are made in regards to surgical planning in patients with CSM.

Methods
Twenty preoperative lateral cervical digital radiographs of patients with CSM were analyzed by 3 independent observers on 3 separate occasions using a software measurement program. Sagittal measurements included C2–7 angles utilizing the Cobb and posterior tangent methods, as well as a straight-line method to measure effective spinal canal lordosis from the dorsal-caudal aspect of the C2–7 vertebral bodies. Analysis of variance for repeated measures or Cohen 3-way (kappa) correlation coefficient analysis was performed as appropriate to calculate the intra- and interobserver reliability for each parameter. Discrepancies in angular and effective lordosis measurements were analyzed.

Results
Intra- and interobserver reliability was excellent (intraclass coefficient > 0.75, kappa > 0.90) utilizing all 3 techniques. Four discrepancies between angular and effective lordotic measurements occurred in which images with a lordotic angular measurement did not have lordosis within the ventral spinal canal. These discrepancies were caused by either spondylolisthesis or dorsally projecting osteophytes in all cases.

Conclusions
Although they are reliable, traditional methods used to make angular measurements of sagittal cervical spine alignment do not take into account ventral obstructions to the spinal cord. The effective lordosis measurement method provides a simple and reliable means of determining clinically significant lordosis because it accounts for both overall alignment of the cervical spine as well as impinging structures ventral to the spinal cord. This method should be considered for use in the treatment of patients with CSM.
Effect of apolipoprotein E genotype on the outcome after anterior cervical decompression and fusion in patients with cervical spondylotic myelopathy
Authors: Setzer Matthias , Vrionis Frank D. , Hermann Elvis J. , Seifert Volker , Marquardt Gerhard 
Published: February 2011

Object
The authors examined a possible association between apolipoprotein E (APOE) gene polymorphism and the outcome after anterior microsurgical decompression in patients with cervical spondylotic myelopathy (CSM).

Methods
The authors conducted a prospective study of 60 consecutive patients (40 men, 20 women) with CSM who underwent anterior microsurgical decompression. The patients ranged in age from 26 to 86 years (mean 61.5 ± 14.6 years). Neurological deficits were classified according to the modified Japanese Orthopaedic Association Scale. Mean follow-up was 18.8 ± 4.6 months and APOE genotyping was carried out by isolation of DNA from venous blood samples. The APOE genotypes were determined by polymerase chain reaction followed by restriction enzyme digestion and polyacrylamide gel electrophoresis of digested fragments. Categorical variables were analyzed with the chi-square test, continuous data with the Mann-Whitney U-test, and for multiple groups with the Kruskal-Wallis H-test. A backward stepwise binary logistic regression analysis was performed to determine the effect of APOE in a multivariate model.

Results
Of the 60 patients with CSM, 35 (58.3%) improved and 25 (41.7%) did not improve or suffered deterioration (no-improvement group). In the improvement group 5 patients (8.3%) possessed the ε4 allele compared with 16 patients (26.7%) in the no-improvement group (p = 0.002, OR 3.3, 95% CI 1.7–6.1). In a multivariate model, the occurrence of the ε4 allele was a significant independent predictor for no improvement after anterior decompression and fusion (p = 0.004, OR 8.6, 95% CI 5.1–20.6).

Conclusions
The results of this study show that APOE gene polymorphism influences the short-term outcome of CSM patients after surgical decompressive and stabilizing therapy in the way that the presence of the APOE ε4 allele is an independent predictor for a no improvement. The presence of APOE may explain in part the different responses to operative therapies in patients with cervical myelopathy.
Changes in cervical range of motion and sagittal alignment in early and late phases after total disc replacement: radiographic follow-up exceeding 2 years
Authors: Ahn Poong-Gi , Kim Keung Nyun , Moon Sung Whan , Kim Keun Su 
Published: February 2011

Object
This was a retrospective clinical study in which the follow-up period exceeded 2 years. The authors investigated the time course of radiographic changes in the cervical range of motion (ROM) and sagittal alignment after cervical total disc replacement involving the ProDisc-C artificial disc.

Methods
Eighteen patients who underwent C5–6 total disc replacement were followed for an average of 27 months. Cervical neutral and flexion-extension lateral radiographs were obtained before and at 1 and 3 months after surgery for early-phase observations and at the last follow-up for late-phase observation. Segmental ROM values in the treated, superior, and inferior adjacent segments were measured. For whole-neck motion, C2–7 ROM was also measured. The percentage contributions of ROM at functional and adjacent segments to whole-neck motion were calculated. For evaluating sagittal alignment, C2–7 and C5–6 Cobb angles were measured. All data from ProDisc-C arthroplasty were compared with the results obtained in 22 patients who underwent C5–6 interbody fusion in which a Solis cage was used and who were followed for an average of 25 months

Results
In the ProDisc-C group, C2–7 and C5–6 ROM significantly decreased in the early phase after surgery and returned to preoperative levels in the late phase. Both superior and inferior adjacent segments showed significantly decreased ROM in the acute phase after surgery and returned to the preoperative values in the late phase. In terms of contributions to whole-neck motion, the ROM of the functional and adjacent segments did not change significantly compared with the preoperative ROM. In the cage group, C2–7 ROM was also significantly decreased in the early phase after surgery and returned to preoperative levels at the late phase. Both superior and inferior adjacent segments exhibited significantly increased ROM and percentage contributions to whole-neck motion in the early and late phases. Sagittal alignment of the whole cervical spine became significantly more lordotic in the late phase in the ProDisc-C group. The C5–6 Cobb angle became significantly lordotic in the ProDisc-C group, whereas there was no significant change in C5–6 Cobb angle in the cage group.

Conclusions
In the early phase after ProDisc-C replacement, the ROM of the entire neck as well as functional and adjacent segments decreased but, at the late phase, they returned to the preoperative state. Contributions of functional and adjacent segments to whole-neck motion were not changed after ProDisc-C replacement. Adjacent-segmental motion could be saved by ProDisc-C replacement instead of interbody cage fusion. Segmental degenerative kyphosis was significantly corrected in patients who underwent ProDisc-C replacement.
Microvascular system of the lumbar dorsal root ganglia in rats. Part II: neurogenic control of intraganglionic blood flow
Authors: Kobayashi Shigeru , Mwaka Erisa Sabakaki , Baba Hisatoshi , Kokubo Yasuo , Yayama Takafumi , Kubota Masafumi , Nakajima Hideaki , Meir Adam 
Published: February 2011

ObjectThe dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG.MethodsTen Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromaticl-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene–related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope.ResultsIn the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E–positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation.ConclusionsThe presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.
Percutaneous pulsed radiofrequency applied to the L-2 dorsal root ganglion for treatment of chronic low-back pain: 3-year experience
Authors: Tsou Hsi-Kai , Chao Shao-Ching , Wang Chao-Jan , Chen Hsien-Te , Shen Chiung-Chyi , Lee Hsu-Tung , Tsuei Yuang-Seng 
Published: February 2011

Object
The authors assessed the effectiveness of percutaneous pulsed radiofrequency treatment for providing pain relief in patients with chronic low-back pain with or without lower-limb pain.

Methods
Data were obtained in 127 patients who had chronic low-back pain with or without lower-limb pain due to a herniated intervertebral disc or previous failed back surgery and who underwent pulsed radiofrequency treatment. Their conditions were proven by clinical features, physical examination, and imaging studies. Low-back pain was treated with pulsed radiofrequency applied to the L-2 dorsal root ganglion (DRG) and lower-limb pain was treated with pulsed radiofrequency applied to the L3–S1 DRG. Patients underwent uni- or bilateral treatment depending on whether their low-back pain was unilateral or bilateral. A visual analog scale was used to assess pain. The patients were followed up for 3 years postoperatively.

Results
In patients without lower-limb pain (Group A), 27 (55.10%) of 49 patients had initial improvement ≥ 50% at 3-month follow-up. At 1-year follow-up, 20 (44.44%) of 45 patients in Group A had pain relief ≥ 50%. An analysis of patients with pain relief ≥ 50% for at least 1 month showed that the greatest effect was at 3 months after treatment. In patients with low-back pain and lower-limb pain (Group B), 37 (47.44%) of 78 patients had initial improvement ≥ 50% at 3-month follow-up. At 1-year follow-up, 34 (45.95%) of 74 patients had pain relief effect ≥ 50%. An analysis of patients in Group B with pain relief ≥ 50% for at least 1 month showed that the greatest effect was at 1 month after treatment.

Conclusions
The results of this prospective analysis showed that treatment with pulsed radiofrequency applied at the L-2 DRG is safe and effective for treating for chronic low-back pain. Satisfactory pain relief was obtained in the majority of patients in Group A with the effect persisting for at least 3 months. The results indicate that pulsed radiofrequency provided intermediate-term relief of low-back pain. Further studies with long-term follow-up are necessary.
A clinical analysis of 4- and 6-year follow-up results after cervical disc replacement surgery using the Bryan Cervical Disc Prosthesis
Authors: Goffin Jan , van Loon Johan , Van Calenbergh Frank , Lipscomb Bailey 
Published: February 2011

Object
In this study, long-term results are presented from clinical studies of the Bryan Cervical Disc Prosthesis at University Hospital Gasthuisberg in Leuven, Belgium. A total of 98 patients (89 with 1-level and 9 with 2-level implantations) agreed to participate in follow-up studies for up to 10 years postoperatively. This article focuses on the 4- and 6-year results. Patients in one of the clinical studies had either radiculopathy or myelopathy associated with spondylosis and/or disc herniations that did not respond to conservative treatment. Patients from the other clinical study received commercially available Bryan devices and the study protocol did not have specific inclusion/exclusion criteria. More than 90% of the patients were considered to have radiculopathy.

Methods
Clinical measurements discussed in the article include the 36-Item Short Form Health Survey, Neck Disability Index, numerical ratings of neck and arm pain, neurological outcomes, and Odom classification. Angular motion findings from lateral flexion-extension radiographs are also presented. The occurrence of adverse events and second surgeries are examined as an indicator of device safety.

Results
The clinical outcomes at 4 and 6 years postoperatively appear consistent with the previously reported results at 1 and 2 years postoperatively. The mean angular motion results at 4 and 6 years postoperatively for 1-level patients were 7.3 and 7.7°, respectively. Two-level patients had slightly less motion at 4 and 6 years postoperatively with mean caudad values of 5.7 and 6.0°, respectively, and cephalad values of 4.2 and 6.2°, respectively. Efforts were made to capture adverse events, regardless of their nature and relatedness to the study surgery. This effort resulted in a relatively high number of recorded events. However, only 6 patients experienced events that were judged by the investigator to be related, either possibly or definitely, to the Bryan device. These events included device migration, device removal, and hoarseness and vocal cord paralysis, as well as 3 cases involving pain and neurological symptoms. Eight patients underwent further neck surgery to treat symptoms.

Conclusions
The favorable clinical and angular motion outcomes that were previously noted at 1- and 2-years' follow-up after cervical disc replacement with the Bryan Cervical Disc Prosthesis appear to persist after 4 and 6 years of follow-up.
Which lumbar interbody fusion technique is better in terms of level for the treatment of unstable isthmic spondylolisthesis?
Authors: Kim Jin-Sung , Lee Kil-Yong , Lee Sang-Ho , Lee Ho-Yeon 
Published: February 2011

ObjectThe purpose of this study was to investigate and compare clinical and radiographic outcomes of 2 kinds of lumbar interbody fusion (LIF) for the treatment of adult low-grade isthmic spondylolisthesis at L4–5 and L5–S1 levels.MethodsThe medical records and radiographs of 86 patients who underwent anterior LIF (ALIF) (L4–5, 42 patients; L5–S1, 44 patients) and 42 patients who underwent transforaminal LIF (TLIF) (L4–5, 22 patients; L5–S1, 20 patients) between 2001 and 2004 were retrospectively reviewed. Clinical results were investigated using the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, and using radiographic measurements, including disc height (DH), degree of spondylolisthesis, segmental lordosis, whole lumbar lordosis (WL), sacral slope (SS), and pelvic tilt; the L-1 axis S-1 distance (LASD) and pelvic incidence were also obtained.ResultsIn both groups, VAS and ODI scores had significantly improved at both treatment levels. Statistical analysis showed no significant difference in postoperative VAS scores between groups at the L4–5 level and in postoperative VAS/ODI scores at the L5–S1 level. However, ODI scores were better in the TLIF than in the ALIF group at the L4–5 level. In terms of radiological changes, there were no significant differences between the 2 groups at the L4–5 level; however, at the L5–S1 level, radiographic results indicated that ALIF was superior to TLIF in its capacity to restore DH, WL, SS, and LASD. The radiological evidence of fusion shows no intergroup difference and no interlevel difference.ConclusionsConsidering the clinical and radiological outcomes in both groups, the authors recommend that instrumented mini-TLIF is preferable at the L4–5 level, whereas instrumented mini-ALIF might be preferable at the L5–S1 level for the treatment of unstable isthmic spondylolisthesis.
Long-term back pain after a single-level discectomy for radiculopathy: incidence and health care cost analysis
Authors: Parker Scott L. , Xu Risheng , McGirt Matthew J. , Witham Timothy F. , Long Donlin M. , Bydon Ali 
Published: February 2011

ObjectThe most common spinal procedure performed in the US is lumbar discectomy for disc herniation. Longterm disc degeneration and height loss occur in many patients after lumbar discectomy. The incidence of mechanical back pain following discectomy varies widely in the literature, and its associated health care costs are unknown. The authors set out to determine the incidence of and the health care costs associated with mechanical back pain attributed to segmental degeneration or instability at the level of a prior discectomy performed at their institution.MethodsThe authors retrospectively reviewed the data for 111 patients who underwent primary, single-level lumbar hemilaminotomy and discectomy for radiculopathy. All diagnostic modalities, conservative therapies, and operative treatments used for the management of postdiscectomy back pain were recorded. Institutional billing and accounting records were reviewed to determine the billed costs of all diagnostic and therapeutic measures.ResultsAt a mean follow-up of 37.3 months after primary discectomy, 75 patients (68%) experienced minimal to no back pain, 26 (23%) had moderate back pain requiring conservative treatment only, and 10 (9%) suffered severe back pain that required a subsequent fusion surgery at the site of the primary discectomy. The mean cost per patient for conservative treatment alone was $4696. The mean cost per patient for operative treatment was $42,554. The estimated cost of treatment for mechanical back pain associated with postoperative same-level degeneration or instability was $493,383 per 100 cases of first-time, single-level lumbar discectomy ($4934 per primary discectomy).ConclusionsPostoperative mechanical back pain associated with same-level degeneration is not uncommon in patients undergoing single-level lumbar discectomy and is associated with substantial health care costs.