Upper cervical spine chordoma of C2–C3

Chordoma is a rare low-grade malignant neoplasm derived from the remnants of the embryonic notochord. This locally invasive neoplasm is subject to recurrence after treatment. The median survival time is estimated to be 6.3 years. Various treatment approaches have been attempted, including radical excision, radiotherapy and chemotherapy. Treatment outcome is significantly influenced by the size and site of the chordoma. Recently, Imatinib, a molecular-targeted agent, has been shown to have antitumor activity in chordoma. Proton radiotherapy, stereotactic radiotherapy and intensity-modulated radiotherapy have also been used. Surgical treatment is still the primary choice for chordoma. It has become more aggressive in recent years, evolving from intralesional or partial excision to en bloc resection. However, upper cervical localizations make such en bloc resection in most cases not possible. We present and discuss the therapeutic challenges of a young female with large retropharyngeal chordoma who presented to our institution after conventional photon beam radiotherapy. This C2/3 tumor was classified IB according to the Enneking classification. It distributed to layers A–D and sectors 1–6 according to the Weinstein Boriani Biagini Classification. The left vertebral artery (VA) was encapsulated and displaced. One stage intralesional extracapsular tumor excision and reconstruction was achieved by combined bilateral high anterior cervical approaches and posterior approach. No recurrence or metastasis was observed 3 years after the operation. She returned to her previous occupation as office worker.     

Clinical and radiologic outcome of laminar screw at C2 and C7 for posterior instrumentation—review of 25 cases and comparison of C2 and C7 intralaminar screw fixation

BackgroundThe aim of this study is 2-fold: to analyze a clinical case series in which we used laminar screws for cervical posterior instrumentation and to describe the difference between C2 and C7 laminar screws in terms of technique and anatomy.MethodsData were obtained from 25 patients who underwent cervical posterior fixation with intralaminar screws at C2 or C7. C2 intralaminar screw instrumentation was used for 7 patients requiring occipitocervical fixation (basilar invagination [3 patients], C1 unstable bursting fracture [1 patient], C1-C2 instability with occipital assimilation [2 patients], and dystopic os odontoideum [1 patient]), 13 patients with C1-C2 instability, 1 patient with C2-C3 subluxation, and 4 patients undergoing C7 fixation due to pseudoarthrosis or cervical instability after trauma. A total of 34 laminar screws were placed including 1 thoracic laminar screw, and the patients were assessed both clinically and radiographically.ResultsThere were no instances where a screw violated the spinal canal nor any hardware fractures noted during the follow-up period. As for perioperative complications, there were 2 cases of postoperative wound infection, 1 case of dural laceration during dissection, and 2 cases of partial dorsal laminar breach. However, there was no neurologic compromise in any of the cases. The fusion success rate was 100%.ConclusionThese preliminary results support the use of intralaminar screws for posterior instrumentation at C2 and C7.     

Membranous nephropathy with predominance of C1q: another variant of C1q nephropathy?

Originally described as a proliferative glomerulonephritis, C1q nephropathy is nowadays mostly recognized as a variant of focal segmental glomerulosclerosis or minimal change disease. We describe a 30-year-old male patient with nephrotic range proteinuria. Kidney biopsy demonstrated a membranous nephropathy with predominant staining for C1q. Under conservative therapy the outcome was favorable. We suggest that this case represents another variant of C1q nephropathy, thus broadening the spectrum of the disease.     

Bilateral C1 laminar hooks combined with C2 pedicle screws fixation for treatment of C1–C2 instability not suitable for placement of transarticular screws

The study design described here is a posterior C1–C2 fusion technique composed of bilateral C1 hooks and C2 pedicle screws. In addition, the clinical results of using this method on 13 patients with C1–C2 instability are reported. The objectives are to introduce a new technique for posterior C1–C2 fusion and to evaluate the clinical outcome of using it to treat C1–C2 instability. From October 2006 to August 2008, 13 patients (9 men and 4 women) with C1–C2 instability were included in this study: 3 had acute odontoid fractures, 4 had obsolete odontoid fractures, 4 had os odontoideum and 2 had traumatic rupture of the transverse ligament. All patients underwent posterior atlantoaxial fixation with bilateral C1 hooks and C2 pedicle screws. The mean follow-up duration was 25 months (range 13–30 months). Each patient underwent a complete cervical radiograph series, including anterior–posterior, lateral, and flexion–extension views, and a computed tomographic scan. The clinical course was evaluated according to the Frankel grading system. No clinically manifested injury of the nerve structures or the vertebral artery was observed in any of these cases. Five patients with neurological symptoms showed significant improvement in neurological function postoperatively. Bony fusion and construction stability were observed in all 13 patients (100%) on their follow-up radiographs, and no instrument failure was observed. Bilateral C1 hooks combined with C2 pedicle screws can be used as an alternative treatment method for C1–C2 dislocation, especially in cases not suitable for the use of transarticular screws. The clinical follow-up shows that this technique is a safe and effective method of treatment.     

The incidence of C5–C6 radiculopathy as a complication of extensive cervical decompression: own results and review of literature

This retrospective study aims to discuss and compare our results with those previously mentioned in the literature with regard to C5–C6 radiculopathy that occurs after decompression carried out for cervical spondylotic myelopathy. There are few reports in the literature referring to the incidence of the C5–C6 radiculopathy following cervical decompression procedures. Some authors believe that the postoperative cord shift is the most likely cause. From January 1994 to November 2002, 121 patients underwent cervical corpectomies for cervical spondylotic myelopathy. The preoperative and the postoperatively discovered paresis have been assessed according to the criteria of the British Medical Council. The Nurick Scale was used to grade the severity of the myelopathic changes. The follow-up period varied from 4 to 111 months with an average of 50 months. Symptoms of C5 and/or C6 radiculopathy appeared in 10 patients (8.2%) postoperatively. Aggravation of a preoperative C5 and/or C6 radiculopathy was seen in 3 patients, while 7 patients developed a new C5 and/or C6 radiculopathy in the immediate postoperative period. These motor deficits resolved completely in 7 patients within 7 months of surgery, whereas a residual motor weakness remained in the other 3 patients. The postoperative C5 motor deficit is not infrequently associated with partial involvement of the C6 root. The lesions can be either unilateral or bilateral with a statistically average frequency of 8%. The prognosis is generally favorable. Our results did not support the hypothesis that the claimed cord shift phenomenon is a possible aetiology.     

Preliminary CT study of C1–C2 rotational mobility in normal subjects

A CT study of normal atlanto-axial (C1–C2) rotary mobility was carried out on ten normal immature subjects. In order to determine the limits of normality, the ten children underwent clinical and radiological examination. The clinical study included checking for objective signs of joint laxity and measurement of rotational neck mobility. The radiological study included standard lateral radiographs in neutral and maximal flexion positions and a CT scan taken in maximal left and right side rotation at the C1–C2 articular processes joint. The superpositioning of the images taken in every rotational direction showed, in all ten children, a wide contact loss between the C1–C2 corresponding facets, ranging from 74 to 85% of the total articular surface. The report on these images, carried out by three independent radiologists, concluded that there was a rotary subluxation in all cases. In the ten children studied, there were no significant differences with regard to neck mobility or laxity signs in clinical or standard X-ray examination. Our results lead us to conclude that, except for complete C1–C2 rotational dislocation with facet interlocking, a CT scan showing a wide – but incomplete – rotational facet displacement is not sufficient to define a status of subluxation. This leads us to perceive that there is a risk of overdiagnosis when evaluating upper cervical spine rotational problems in children. The concept of both rotary C1–C2 fixation and subluxation should be revised. Received: 6 November 1997 Revised: 1 February 1999 Accepted: 11 February 1999     

Study on clinical application of selective transfer of ipsilateral C7 nerve root

Objective:To verify the rationality,reliability and practivability of selective transfer of ipsilateral C7 nerve root for treatment of upper trunk avulsion.Methods:Selective transfer of ipsilateral C7 nerve root was carried out in 8 patients (7 with upper trund avulsion,and 1 with left upper trunk avulsion combined with partial injury of the middle trunk)from June 1996 to Februany 1997.selective transfer of the anterior division or the anteriolateral fascicles of the anterior division of ipsilateral C7 to the anterior division of the upper trunk was performed under general anesthesia.Only 5 cases were followed up.Results:Among these 5 cases,effective recovery was observed on 4 cases of the transfer of the anteriolateral fascicles of ipsilateral C7 to the anterior division of the upper trunk.Electromyogyaphic examination showed nerve regeneration could be observed in the 2nd month postoperatively.And detectable elbow flexion by biceps contraction was found in the 4th month postoperatively.The function of the C7 innervating muscles was not jeopardized,and the case with combined partial C7 root injury had a poor result.Conclusions:Selective transfer of ipsilateral C7 nerve root leads to a restoration of reinnervating muscle functions without affecting the function of the muscles innervated by C7.It is therefore a practicable new surgical procedure for treating upper trunk avulsions.     

Relations of transcription expression of IL—2 with nuclear factor of activated T cells as well as changes of C—Fos and C—Jun after trauma

Objective:To observe the relations among expression of interleukin-2(IL-2)in spleen lymphocytes,DNA binding activity of nuclear factor of activated T cells(NFAT)and expression of the partly family members C-Fos,C-Jun after trauma.Methods:A murine closed trauma model was used,animals were sacrificed6,12hours and 1,4,7,10,14days,respectively after injury,Spleen lymplocytes were isolated from injured mice and stimulated with concanavalin-A,The culture supernatants were harvested and assayed for IL-2activity,Total RNA was extracted from spleen lymphocytes and assayed for IL-2mRNA.Nuclear protein was extracted,and the DNA binding activity of NFAT was measured using an electrophoretic mobility shift assay(EMSA),the expressions of C-Fos,C-Jun protein determined by Western blot analysis.Results:The expressions of IL-2 activity and IL-2mRNA in spleen lymphocytes were decreased in injured mice compared with those in control mice,and the most obvious decrease appeared on the 4th day after injury,The DNA binding activity of NFAT decreased gradually and reached the minimum that was only41%of the control on the 4th day after injury,which was cloely associated with the decline of IL-2activity and IL-2mRNA.An decrease in the expression ofC-Fos on the lst and 4th day after injury,trauma had no significant effect on the C-Jun expression.Conclusions:These results suggest that the inhibition of IL-2 expression is partly due to the impairment in the activation of NFAT in injured mice;and the decline in the DNA binding activity of NFAT is partly due to trauma block in the C-Fos expression.     

Risk of vertebral artery injury: comparison between C1–C2 transarticular and C2 pedicle screws

Background contextTo our knowledge, no large series comparing the risk of vertebral artery injury by C1–C2 transarticular screw versus C2 pedicle screw have been published. In addition, no comparative studies have been performed on those with a high-riding vertebral artery and/or a narrow pedicle who are thought to be at higher risk than those with normal anatomy.PurposeTo compare the risk of vertebral artery injury by C1–C2 transarticular screw versus C2 pedicle screw in an overall patient population and subsets of patients with a high-riding vertebral artery and a narrow pedicle using computed tomography (CT) scan images and three-dimensional (3D) screw trajectory software.Study designRadiographic analysis using CT scans.Patient sampleComputed tomography scans of 269 consecutive patients, for a total of 538 potential screw insertion sites for each type of screw.Outcome measuresCortical perforation into the vertebral artery groove of C2 by a screw.MethodsWe simulated the placement of 4.0 mm transarticular and pedicle screws using 1-mm-sliced CT scans and 3D screw trajectory software. We then compared the frequency of C2 vertebral artery groove violation by the two different fixation methods. This was done in the overall patient population, in the subset of those with a high-riding vertebral artery (defined as an isthmus height ≤5 mm or internal height ≤2 mm on sagittal images) and with a narrow pedicle (defined as a pedicle width ≤4 mm on axial images).ResultsThere were 78 high-riding vertebral arteries (14.5%) and 51 narrow pedicles (9.5%). Most (82%) of the narrow pedicles had a concurrent high-riding vertebral artery, whereas only 54% of the high-riding vertebral arteries had a concurrent narrow pedicle. Overall, 9.5% of transarticular and 8.0% of pedicle screws violated the C2 vertebral artery groove without a significant difference between the two types of screws (p=.17). Among those with a high-riding vertebral artery, vertebral artery groove violation was significantly lower (p=.02) with pedicle (49%) than with transarticular (63%) screws. Among those with a narrow pedicle, vertebral artery groove violation was high in both groups (71% with transarticular and 76% with pedicle screws) but without a significant difference between the two groups (p=.55).ConclusionsOverall, neither technique has more inherent anatomic risk of vertebral artery injury. However, in the presence of a high-riding vertebral artery, placement of a pedicle screw is significantly safer than the placement of a transarticular screw. Narrow pedicles, which might be anticipated to lead to higher risk for a pedicle screw than a transarticular screw, did not result in a significant difference because most patients (82%) with narrow pedicles had a concurrent high-riding vertebral artery that also increased the risk with a transarticular screw. Except in case of a high-riding vertebral artery, our results suggest that the surgeon can opt for either technique and expect similar anatomic risks of vertebral artery injury.     

Why 37 degrees C? Evolutionary fundamentals of thermoregulation

Homeothermy is the result of an evolutionary process during which every increase in oxygen supply led to a consecutive increase in metabolic rate and, thus, to a new dependence on favorable ambient conditions. In response to the food scarcity of winter months, some inhabitants of temperate zones developed an ability to hibernate which is characterized by a fully thermocontrolled reduction in body temperature down to near zero values. Hibernation thus illustrates that in homeotherms, not only the body shell is poikilothermic, but also the core temperature is more variable than often assumed. However, in contrast to clinical hypothermia, natural torpidity does not consist of a cold-induced reduction in metabolic rate, but of an endogenous metabolic reduction with subsequent lowering of body temperature. As a factor of metabolic suppression, the pH has been suspected which, in hibernators, is kept constant at 7.4 by relative hypoventilation (pH-stat) which differs from its passive shift in the poikilothermic body shell (alpha-stat). In clinical hypothermia, temperature governs the metabolic rate in that, depending on the state of thermoregulation, either a cold defense reaction with an increased metabolic rate (accidental hypothermia) or a cold-induced reduction in metabolic rate (induced hypothermia) occurs. However, as can be learned from hibernators, the lower limit of hypothermia tolerance seems to be due to a uniform minimal metabolic rate rather than to the species-specific body temperature at which this metabolic limit is reached, depending on body size and basal metabolic rate. Accordingly, in judging the sequelae of hypothermia, the degree of cooling should be given less emphasis than the resulting effects on metabolic rate.     

C7 sagittal vertical axis is the determinant of the C5–C7 angle in cervical sagittal alignment

Background Context

Previous studies have indicated that the T1 slope correlates with cervical lordosis. In contrast, the specific impact of the C7 sagittal vertical axis (C7SVA) on cervical lordosis remains unknown.

Management of urethrocutaneous fistula after hypospadias surgery �C An experience of thirty-five cases

Introduction:

The commonest complication following hypospadias repair is occurrence of urethrocutaneous fistula. The smaller fistulas (<2 mm) are easier to close with a simple closure whereas larger ones (>2 mm) with good vascular surrounding skin require a local skin flap closure for avoiding overlapping suture lines. For the recurrent/larger fistulas with impaired local surrounding skin - incidence of recurrence is significantly reduced by providing a waterproofing interposition layer.

Aims:

To study the effect of size, location, number of fistulas and surrounding tissues in selecting the procedure and its outcome. To identify various factors involved in the recurrence and to formulate a management in the cases where recurrence has occurred.

Patients and Methods:

This study of 35 cases of urethrocutaneous fistula repair was done from July 2006 to May 2009 to achieve better results in fistula management following hypospadias surgery.

Statistical analysis used:

X² test and Fisher''s exact test.

Results:

The overall success rate for fistula repair at first attempt was 89% with success rates for simple closure, layered closure and closure with waterproofing layer being 77%,89% and 100%, respectively. The second attempt success rate at fistula repair for simple closure and closure with waterproofing layer were 33% and 100%, respectively. At third attempt the two recurrent fistulas were managed by simple closure with a waterproofing interposition layer with no recurrence. All the waterproofing procedures in this study had a success rate of 100%.

Conclusions:

The treatment plan for a fistula must be individualized based on variables which has an effect on the outcome of repair and to an extent dictates the type of repair to be performed. The significantly improved success rates with the addition of a waterproofing layer suggests the use of this interposition layer should be done at the earliest available opportunity to prevent a reccurence rather than to reserve it for future options.     

Effect of 30°C Heat on the Anaerobic Capacity of Heat Acclimatised Athletes

The main finding of this study was that for heat acclimatised athletes, there was no significant difference (p=0.58) in anaerobic capacity for temperate (21.8 ± 0.5 °C; 52 ± 5 % relative humidity) compared with warm conditions (29.6 ± 0.5 °C; 51 ± 9 % relative humidity). Anaerobic capacity was estimated using the maximal accumulated oxygen deficit (MAOD) during constant intensity cycling at 120% peak rate of O₂ consumption until exhaustion. This yielded mean MAOD values of 3.3 ± 0.9 and 3.5 ± 1.1 L for temperate and warm conditions, respectively. Peak post-exercise lactate values of 14.7 ± 3.8 and 14.4 ± 4.5 mmol·L^-1 for temperate and warm conditions respectively, were also not significantly different (p=0.72). Time to exhaustion (TTE) was similarly unchanged (p=0.56), being 175 ± 19 and 170 ± 18 s for temperate and warm conditions, respectively. These results suggest that the MAOD remains a valid test throughout environmental temperatures for the range of 20-30 °C when used with heat acclimatised athletes.Key Words: Maximal accumulated oxygen deficit, anaerobic metabolism, environmental temperature, maximal exercise     

How do C6/C7 tetraplegic patients grasp balls of different sizes and weights? Impact of surgical musculo-tendinous transfers

STUDY DESIGN: Prospective control cohort study. OBJECTIVES: To develop a new test to analyse qualitatively grasping strategies in C6/C7 tetraplegic patients, and to quantify the effect of musculo-tendinous transfers. SETTING: France. METHODS: Twelve C6/C7 tetraplegic adults (17 arms; 31.3+/-7.9 years) and 17 healthy subjects (30.9+/-9.4 years) completed the study. We assessed participants' ability to grasp, move and release standardized balls of variable sizes and weights. OUTCOME MEASURES: Failures, movement duration (MD), grip patterns, forearm orientation during transport. RESULTS: In patients as well as in controls, the number of digits involved in prehension increased proportionally to the size and weight of the ball. C6 non-operated tetraplegic patients failed 38.2% of the tasks. They frequently used supine transport (51.4% of successful tasks). MD was longer, with a large distribution of values. The presence of active elbow extension poorly influenced the amount of failure nor grip configuration, but significantly reduced MD and supine transport (34%). Patients who were evaluated after hand surgery showed a trend towards improved MD and more frequent completion (failure 30%), especially for middle-sized and middle-weighted balls. Grip patterns were deeply modified, and all transports were made in pronation. CONCLUSION: The 'Tetra Ball Test' evidences the characteristics of grasping in tetraplegic patients and those influenced by surgery. It may be useful in understanding effects of surgical procedures. This preliminary study must be completed to evaluate the quantitative responsiveness and reproducibility of this test and to develop instrumented electronic balls to optimise it.     

Management of a 3-year-old with an unstable C6–C7 diastasis without quadriplegia

Background

Caring for pediatric spine trauma patients places spine surgeons in situations that require unique solutions for complex problems. Recent case reports have highlighted a specific injury pattern to the lower cervical spine in very young children that is frequently associated with complete spinal cord injury.

Methods

This report describes the presentation and treatment of a C6–C7 dislocation in a 3-year-old patient with an incomplete spinal cord injury. The highly unstable cervical injury and the need to prevent neurologic decline added complexity to the case.

Results

A multi-surgeon team allowed for ample manpower to position the patient; with individuals with the requisite training and experience to safely move a patient with a highly unstable cervical spine. Initial closed reduction under close neurophysiologic monitoring, posterior fusion and immediate anterior stabilization lead to a successful patient outcome with preserved neurologic function. A traumatic cerebrospinal fluid leak, while a concern early on during the procedure, resolved without direct dural repair and did not complicate the patient’s fusion healing. Additional anterior stabilization and fusion allowed long-term stability with bone healing that may not be achievable with posterior fixation and/or soft tissue healing alone.

Conclusions

Familiarity with the challenges and solutions presented in the case may be useful to surgeons who could face a similar challenge in the future.