Posterior Cervical Arthrodesis Research Articles

Autologous rib graft for posterior cervical fusion in pediatric patients: efficacy and safety in the early postoperative period.

The objective was to describe the indications, technique, and initial outcomes of autologous rib graft with recombinant human bone morphogenetic protein (rhBMP) in pediatric patients undergoing posterior cervical fusion. A retrospective study was performed of all pediatric patients who underwent autologous rib grafting with extra-small rhBMP-2 for posterior craniocervical or cervical arthrodesis at a single institution between May 2020 and July 2023. Patients with less than 3 months of postoperative follow-up and no postoperative CT data were excluded. Primary outcomes included presence of fusion on CT, 30-day perioperative complications, and rib harvest complications. Twenty-eight sequential patients met inclusion criteria. Thirteen were male, 15 were female, and the average age was 9 years. There were no surgical site infections or instances of postoperative seroma or unplanned return to the operating room. All patients had solid fusion on postoperative CT at 3 months. The average follow-up was 14.5 months, with a range of 4 months to 3 years. There were no complications associated with the rib harvest, including no instances of harvest site pain, and all patient incisions healed well. The authors' preliminary results demonstrate that autologous rib graft with extra-small rhBMP-2 is an effective strategy to achieve a high rate of fusion in pediatric patients undergoing posterior instrumented craniocervical or cervical fusion. In this series, the authors found an acceptable safety profile, without seroma, surgical site infection, unplanned return to the operating room, or rib harvest complications.

228. Complications following posterior cervical arthrodesis for cervical spondylotic myelopathy: a single institution's experience

<h3>BACKGROUND CONTEXT</h3> Posterior cervical fusion (PCF) is a frequently performed surgery for treatment of cervical spondylotic myelopathy (CSM). While incidences of these risks have been reported previously, prior studies on this topic either contain small sample sizes, pooled from multiple institutional or public databases, or have low follow-up duration. Here, we report the incidence of postoperative complications following PCF for CSM at a single institution with a large patient cohort. To review the rate of postoperative complications following primary posterior cervical fusion for cervical CSM at a single institution. <h3>PURPOSE</h3> To review the rate of postoperative complications following primary posterior cervical fusion for CSM at a single institution. <h3>STUDY DESIGN/SETTING</h3> Retrospective case series, single institution. <h3>METHODS</h3> Patients with a diagnosis of CSM treated with PCF over a 4-year period at a tertiary care center were identified. Exclusion criteria included: (1) cervical myelopathy secondary to trauma, spinal infection, or spinal neoplasm, (2) fusion constructs that proximally included occiput or C1, or distally extended below T2, and (3) revision PCF procedures. Postoperative data collected included incidence of superficial surgical site infection (SSI), deep wound infection, subsequent irrigation and debridement (I&D), postoperative pneumonia, venous thromboembolism (VTE), epidural hematoma, and C5 nerve palsy during course of follow-up. Multivariable regression analyses were performed to identify patient characteristics and comorbidities that were independent risk factors for these complications. <h3>RESULTS</h3> A total of 176 patients met inclusion criteria (mean age + standard deviation = 63.8 + 11.1 years). An average of four levels (range: 1-7) were fused per surgery. Mean follow-up was one year. Of 176 patients, 33 (18.7%) had at least one documented postoperative complication. There were six cases (3.4%) of superficial SSI and four cases (2.3%) of deep wound infection. One patient (0.57%) developed a postoperative epidural hematoma. There were five cases (2.8%) of VTE and six cases (3.4%) of postoperative pneumonia. Fifteen patients (8.5%) developed C5 nerve palsy, of which 12 of 15 cases were transient and improved. Diabetes was an independent risk factor for postoperative VTE (p=0.03) and pneumonia (p=0.03). <h3>CONCLUSIONS</h3> Almost 1 in 6 patients had some complication after posterior cervical fusion for treatment of CSM. The incidence of C5 nerve palsy at 8.5% was not trivial. Though PCF is a routine procedure, our results highlight the need for appropriate preoperative counseling, especially in patients with diabetes mellitus. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

The Outcomes of Posterior Arthrodesis for Atlantoaxial Subluxation in Down Syndrome Patients: A Meta-Analysis.

This is a meta-analysis. To establish rates of (1) neurological complications, (2) bony-related complications, (3) complications delaying recovery, (4) reoperation, and (5) fatalities following posterior cervical arthrodesis in Down syndrome (DS) patients with atlantoaxial subluxation. To determine if presenting symptoms had any relationship to postoperative complications. Posterior arthrodesis is commonly utilized to correct cervical instability secondary to atlantoaxial instability in DS patients. However, there has never been a global evaluation of postoperative complications associated with posterior cervical spinal arthrodesis in DS patients. A comprehensive search of Medline/PubMed, EMBASE, and Ovid databases between January 1980 and July 2017 was utilized to identify DS patients with atlantoaxial subluxation who underwent posterior cervical arthrodesis. Data were sorted by neurological complications, complications delaying recovery, bony-related complications, reoperations, and fatalities. Patients were sorted into 2 groups based on presentation with or without neurological deficits. Twelve studies met inclusion criteria, including 128 DS patients. Mean age was 13.8 years (range: 6.7-32.7 y; 47.8% male). Mean follow-up was 31.7 months (range: 14.9-77 mo). All patients underwent primary posterior cervical arthrodesis with an average of 2.5 vertebrae fused. A total of 39.6% of patients had bony-related complications [95% confidence interval (CI), 31.4%-48.5%], 23.3% had neurological deficits (95% CI, 16.6%-31.6%), and 26.4% experienced complications delaying recovery (95% CI, 19.4%-34.9%). The reoperation rate was 34.9% (95% CI, 25.5%-45.6%). The mortality rate was 3.9% (95% CI, 1.5%-9.7%). Neurological complications were 4-fold (P<0.05) and reoperation was 5.5-fold (P<0.05) more likely in patients presenting with neurological deficits compared with those without. This study detailed global complication rates of posterior arthrodesis for DS patients, identifying bony-related complications and reoperations among the most common. Patients presenting with neurological symptoms and cervical instability have increased postoperative rates of neurological complications and reoperations than patients with instability alone. Further investigation into how postoperative complications effect patient independence is warranted.

Use of Bivector Traction for Stabilization of the Head and Maintenance of Optimal Cervical Alignment in Posterior Cervical Fusions.

Study Design:Retrospective analysis of consecutive case series.Objective:To introduce a novel method of stabilizing the cranium using bivector traction in posterior cervical fusions.Methods:A retrospective review of 50 consecutive patients undergoing instrumented posterior cervical arthrodesis was performed. All patients had at least 3 levels of subaxial fusion using the bivector traction apparatus. Patients’ demographic data was recorded for the following: pre- and postoperative cervical lordosis, pre- and postoperative cervical sagittal vertical alignment (cSVA), and intraoperative complications from pin placements.Results:A total of 50 patients were studied. There were 31 females and 19 males. The mean age at the time of surgery was 49 years (range 35-79). A mean 5.8 levels were fused. The most common levels fused were C2-T3 in 14 patients followed by C2-T2 in 7 patients. In no case did the surgeon or assistant have to scrub out to adjust the alignment. The mean pre- and postoperative cervical lordosis was −6.0° and −10°, respectively (P = .04). The mean pre-and postoperative cSVA was 30.5 mm and 32 mm, respectively (P = .6). There were no complications related to placement of the Gardner-Well tongs.Conclusion:The bivector traction is an easy, safe, and effective method of stabilizing the head and obtaining adequate cervical sagittal alignment.

Neck range of motion following cervical spinal fusion: A comparison of patient-centered and objective assessments

ObjectivesA common question posed by patients undergoing cervical fusion pertains to the likelihood of perceiving a postoperative limitation in neck mobility. The aim of this study was to assess the change in neck mobility after subaxial cervical fusion using an objective range of motion (ROM) measure and patient reported assessment. Patients and methodsPatients older than 18 years of age, undergoing first-time anterior or posterior subaxial cervical arthrodesis for a symptomatic spondylotic process (radiculopathy, cervical spondylotic myelopathy or primary neck pain) at a single center were eligible. Assessment included: 1) neck pain on a numeric rating scale; 2) four-directional objective neck mobility using the validated cervical ROM goniometer; and 3) a novel Mobility Assessment Scale (MAS) for patient perceived neck mobility. Subjects were dichotomized by number of levels fused (1–2 levels and ≥3 levels). ResultsThere were 25 patients with a mean of 2.7±1.5 levels fused. Neck pain was improved in both groups with mean change of −3.4 [95% CI −4.7,−2.1], p=0.004 for 1–2 levels and −3.5 [95% CI −5.4,−1.5], p=0.009 for ≥3 levels. MAS score improved significantly in group undergoing 1–2 level fusion (−1.8 [95% CI: −3.1,−0.4], p=0.016) but not in those with ≥3 levels fused. There was a significant positive correlation between MAS and neck pain in the 1–2 level fusion group (rs=0.667, p=0.012) but not in the ≥3 level group. Objective neck mobility did not changed significantly in either group. ConclusionsPatient reported neck mobility was significantly improved following 1–2 level cervical fusion. This change correlated significantly with patient reported improvement in neck pain. No significant difference in reported neck mobility was found in those undergoing fusion of ≥3 levels.

Management and Outcome of Dens Fracture Nonunions in Geriatric Patients.

Dens fractures are known to have high rates of pseudarthrosis. The aim of this study was to define clinical and radiographic long-term outcomes, specifically in relation to osseous union, cervical spine movement, neurological sequelae, and quality of life, in a geriatric cohort (sixty-five years of age or older) treated operatively or nonoperatively for a dens fracture nonunion. Forty-four patients (twenty-eight women and sixteen men; average age, seventy-two years) met the inclusion criteria and were enrolled in this study. Sixteen patients (36%) underwent operative stabilization with posterior cervical arthrodesis, and twenty-eight (64%) were treated nonoperatively with a predefined protocol. All patients had a post-treatment follow-up period of at least five years. Radiographic evaluation showed osseous union at the site of the C1-C2 arthrodesis in all sixteen patients who had undergone surgical treatment. Clinical follow-up revealed that fourteen had satisfactory results following postoperative rehabilitation. In contrast, radiographic evaluation of the twenty-eight nonoperatively treated patients showed persistence of the pseudarthrosis of the dens in twenty-six and osseous union of the dens in two. All twenty-eight patients (100%) had a satisfactory clinical outcome. C1-C2 arthrodesis was a reliable treatment option for dens fracture nonunions that were unstable, those associated with neurological symptoms, and those causing persistent pain. Clinical and radiographic monitoring was an acceptable nonoperative treatment option but was associated with a very low rate of osseous union of the dens.

Clinical therapeutic effect of surgery on upper cervical spinal cord tumors.

To evaluate the long-term clinical therapeutic effect of polyaxial screw-rod system for posterior cervical arthrodesis on patients with upper cervical spinal cord tumors. From March 2007 to May 2013, 22 patients with upper cervical spinal cord tumors underwent tumor resection and posterior cervical arthrodesis in our institution. The medical records of these patients were reviewed respectively. There were 10 males and 12 females with ages ranging from 16 to 60 years old. Posterior cervical arthrodesis by polyaxial screw-rod was performed at the upper cervical spine (C1-3). All patients were followed-up clinically and radiographically. The average follow-up was 65.5 months. Twenty-two patients were enrolled and a total of 114 screws were placed in this study. Histopathology revealed neurinoma, meningioma, ganglioneuroma and ganglioglioma in 16, 3, 1 and 1 case (s), respectively. The mixed tumor with component of ganglioneuroma and neurinoma was observed in 1 case. All patients received tumor resection and posterior athrodesis by polyaxial screw-rod system. Cervical kyphosis was encountered in one patient and this patient suffered the recurrence of tumor. Solid fusion was achieved in all patients. The average postoperative Japanese Orthopaedic Association (JOA) score was 13.9 and the average recovery rate was 51.4%. Neurologic deterioration was found in 2 patients. No complications, such as spinal cord or vertebral artery injury, postoperative radiculopathy or instrumentation failure, were observed. The long-term clinical therapeutic effects of posterior cervical arthrodesis using polyaxial screw-rod system on upper cervical spinal cord tumors are satisfactory, with no severe complication.

Location of the Vertebral Artery at C1 in Children: How Far Out Laterally Can One Safely Dissect?

There is little information available on the anatomic location of the vertebral artery in pediatric patients undergoing a posterior cervical arthrodesis involving the first cervical vertebra (C1). The purpose of this study was to define how far laterally one can safely dissect posteriorly without risk to the vertebral artery in pediatric patients. A subset of computed tomography angiograms of the neck that had been previously obtained in patients at our institution was evaluated. The location of the vertebral artery was identified on both the right and the left side at the vertebral artery groove. A total of 549 patients were included. The vertebral artery was an average of 13.97 mm (standard deviation, 1.89 mm) from the midline. Ninety-seven percent of the vertebral arteries were more than 1 cm lateral to the midline, and none were less than 8 mm from the midline. There was a significant difference among the age groups in the location of the vertebral artery, with the vertebral artery closer to the midline in younger patients (p < 0.001). In patients eight years of age or older, the average distance from the midline equaled the value reported for adults. Patients under the age of eight years had vertebral arteries that were significantly closer to the midline compared with those of older patients; nonetheless, 97% of the vertebral arteries in the younger patients were more than 1 cm lateral to the midline. Increased care must be taken when dissecting out laterally on C1 in younger patients, as the vertebral artery tends to be closer to the midline than has been described in adults.

Os odontoideum: case report

OBJECTIVE: To report the difficulties in managing a case of os odontoideum. METHODS: Female patient, 12 years old who developed a quadiparesis after minor cervical trauma in October 2005. In the emergency department a congenital cervical anomaly was identified. The patient was placed in a Stryker® frame and, few days later, in a halo bracing. After 3 months, an infection around the pins emerged and the halo vest had to be removed. A severe C1-2 instability persisted and a C1-C2 Gallie procedure was attempted. In the following weeks the bone disappeared and another procedure was attempted in June 2006 - C1 laminectomy and occiput-C3 fusion. In the following months the neurological status of the patient improved and a complete mass of occiput-C3 fusion was observed. RESULTS: We choose a posterior cervical arthrodesis of C1-C2 using the Gallie technique. Since the condition was not resolved we performed a second surgery, C1 laminectomy (determined by SAC of 8, 3 mm in MRI) followed by posterior occiput-C3 fusion. In our case, until now, there is no evidence of axial decompensation, but a more prolonged follow-up is needed. CONCLUSIONS: The treatment of os odontoideum has many considerations but the essential that in the presence of instability and neurological deficit a solid fusion is achieved. In case of failure of posterior atlantoaxial wiring, the occiput-C2 or C3 fusion with rods seems to be an excellent option with a high rate of success, avoiding the need for additional support.

Safety, Efficacy, and Dosing of Recombinant Human Bone Morphogenetic Protein-2 for Posterior Cervical and Cervicothoracic Instrumented Fusion With a Minimum 2-Year Follow-up

Considerable attention has focused on concerns of increased complications with recombinant human bone morphogenetic protein-2 (rhBMP-2) use for anterior cervical fusion, but few reports have assessed its use for posterior cervical fusions. To assess the safety, efficacy, and dosing of rhBMP-2 as an adjunct for instrumented posterior cervical arthrodesis. All patients treated by the senior author with posterior cervical or cervicothoracic instrumented fusion using rhBMP-2 from 2003 to 2008 with a minimum of 2 years of follow-up were included. Diagnosis, levels fused, rhBMP-2 dose, complications, and fusion were assessed. Fifty-three patients with a mean age of 55.7 years (range, 2-89 years) and an average follow-up of 40 months (range, 25-80 months) met inclusion criteria. Surgical indications included basilar invagination (n = 6), fracture (n = 6), atlantoaxial instability (n = 16), kyphosis/kyphoscoliosis (n = 22), osteomyelitis (n = 1), spondylolisthesis (n = 1), and cyst (n = 1). Fifteen patients had confirmed rheumatoid disease. The average rhBMP-2 dose was 1.8 mg per level, with a total of 282 levels treated (average, 5.3 levels; SD, 2.8 levels). Among 53 patients, only 2 complications (3.8%) were identified: a superficial wound infection and an adjacent-level degeneration. No cases of dysphagia or neck swelling requiring treatment were identified. At the last follow-up, all patients had achieved fusion. Despite many of the patients in the present series having complex pathology and/or rheumatoid arthritis, a 100% fusion rate was achieved. Collectively, these data suggest that use of rhBMP-2 as an adjunct for posterior cervical fusion is safe and effective at an average dose of 1.8 mg per level.

Does Smoking Influence Fusion Rates in Posterior Cervical Arthrodesis With Lateral Mass Instrumentation?

Smoking is associated with reduced fusion rates after anterior cervical decompression and arthrodesis procedures. Posterior cervical arthrodesis procedures are believed to have a higher fusion rate than anterior procedures. We asked whether smoking (1) would reduce the fusion rate in posterior cervical procedures; and (2) be associated with increased pain, decreased activity level, and a decreased rate of return of work as compared with nonsmokers. We retrospectively reviewed 158 patients who had a posterior cervical fusion with lateral mass instrumentation and iliac crest bone grafting between 2003 and 2008. Fusion rates and Odom Criteria grades were compared among smokers and nonsmokers. The minimum followup was 3months (average, 14.5months; range, 3-72months). Smokers and nonsmokers had similar fusion rates (100%). Although 80% of patients had Odom Criteria Grade I or II, smokers were five times more likely to have Grade III or IV with considerable limitation of physical activity. Age, gender, and diagnosis did not influence fusion rates or the Odom Criteria grade. In contrast to the effect of smoking on anterior cervical fusion, we found smoking did not decrease posterior cervical fusion with lateral mass instrumentation and iliac crest bone grafting. Posterior cervical fusion with lateral mass instrumentation should be considered over anterior procedures in smokers if the abnormality can appropriately be addressed from a posterior approach. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

PLATE FIXATION OF ODONTOID FRACTURES WITHOUT C1–C2 ARTHRODESIS

Surgical treatment of odontoid fractures that do not allow interfragmentary fracture compression involves either posterior atlantoaxial arthrodesis or additional anterior stabilization using a plate construct. The purpose of this study was to determine the clinical and radiographic outcome after anterior plate fixation of odontoid fractures that were not suitable for anterior screw fixation. We reviewed the clinical and radiographic records of 9 patients with an average age of 54 years at the time of surgery who had undergone anterior plate fixation of an odontoid fracture. Indications for using a plate construct were odontoid fractures with anterior oblique fracture lines, fractures with comminution or major displacement, and pathological fractures. Eight patients returned to their preinjury activity level and were satisfied with their treatment. One patient reported chronic pain symptoms and a notable decrease in cervical spine motion. Using the Smiley-Webster Scale to quantify their clinical outcome, we achieved an overall outcome score of 1.6. Bony fusion was achieved in all patients. Reduction or fixation failed in 2 patients. Reoperation for technical failures was not necessary in any of the patients. We had promising results using anterior plate fixation for surgical treatment of odontoid fractures that did not allow interfragmentary fracture compression. Because this method avoids the rigid fixation of the atlantoaxial joint in contrast to techniques of posterior cervical arthrodesis, it seems to be a practical option for the management of fracture types that require additional stabilization of the odontoid.

Surgical results of posterior cervical arthrodesis with laminar screws

Surgical results of posterior cervical arthrodesis with laminar screws

Significance of Laminar Screw Fixation in the Subaxial Cervical Spine

We retrospectively reviewed 11 patients who underwent laminar screw fixation in the subaxial cervical spine. In 4 patients, laminar screws were inserted for posterior cervical arthrodesis, and in 7 patients it was used for fixation of the open laminae during laminoplasty. In this study, the author describes the technique and surgical results of translaminar screw placement in the subaxial cervical spine. The use of laminar screws for fixation of the second cervical vertebra and upper thoracic vertebrae has been introduced as an important technique in spinal surgery because they can avoid injury to adjacent neurovascular structures. However, there have been no reports of translaminar screw use in the subaxial spine including C7. In this study, we describe the use of translaminar screws for fixation of the subaxial cervical spine in cases of degenerative or traumatic spine disease. Between June 2006 and March 2007, 34 translaminar screws were placed in 11 patients to treat trauma or degenerative disease: 6 at C7, 6 at C6, 7 at C5, 7 at C4, 7 at C3, and 1 at T1. There were 6 women and 5 men. The ages ranged from 23 to 87 years with a mean age of 61.3 years. All patients were evaluated at 6 weeks, as well as at 3 and 6 months using flexion and extension lateral radiographs. Patients requiring fusion were also evaluated with computed tomography at 3 and 6 months to verify arthrodesis. The mean follow-up period was 5.7 months, at which time there was no significant complications from laminar screw placement, except for 2 asymptomatic breaches of the dorsal lamina cortex. Sound bone fusion was identified in cases where arthrodesis was the goal. No screw pullout or avulsion was identified in the laminoplasty cases. The translaminar screw method avoided damaging vascular structures, especially when the vertebral artery courses in the C7 transverse foramen, and it maintains solid stabilization of the subaxial cervical spine. This technique has 2 important advantages to currently used techniques: it is simpler and is not limited by the position of vascular structures. Therefore, it may be applicable to a wider number of patients, especially as it may be used in the subaxial cervical spine.

Halo-vest Treatment of Odontoid Fractures

Treatment of odontoid fractures is controversial and there is no single therapeutic method that is universally accepted. The purpose of this paper is to retrospectively review odontoid fractures treated orthopedically with a halovest. Eighteen patients were retrospectively studied who presented with an odontoid fracture; fractures were treated between 1987 and 2001 by means of a halo vest. Mean age was 38 years (range 16-75 years). Mean followup was 5 years (range: 1-15 years). The most usual mechanism of injury (11 cases) was a road accident. Eight of the fractures were type III and 3 were type II according to Anderson and D’Alonzo's classification. In all cases but three, a standard and CT-scan imaging study was performed. Incorporation was documented by means of plain x-rays and tomographs (in some cases CT-scans were used). Pain, cervical mobility, return to previous activities and neurological status were assessed using the Smiley-Webster scale. Global incorporation rate was 89% (16 cases). In 9 cases (50%) results were excellent, in 4 (22%) they were good, in 3 (16.6%) they were fair and in 2 (11%) poor. Results were good in 6 cases of type II fractures (60%) and 7 cases of type III fractures (87.5%). In 7 cases it was possible to improve reduction by an average 6 mm. In two cases, initial displacement until incorporation increased by 2 mm. Poor results (11.1%) resulted from treatment failure and required a posterior cervical arthrodesis performed with Brooks and Gallie's technique. In 2 of the 5 patients over 60 (40%), treatment failed and a surgical procedure was required to stabilize the fracture. The most significant complications were 5 cases of halo loosening (27.7%), one case of a sensory nerve neuroma and one case of secondary post-traumatic syringomyelia. Orthopedic treatment with a halo-vest allowed us to reduce and stabilize odontoid fractures up to incorporation in 89% of cases, with 66.5% of good results. El tratamiento de las fracturas de odontoides es controvertido, y no existe un único método terapéutico universalmente aceptado. El objetivo del presente trabajo es revisar retrospectivamente las fracturas de odontoides tratadas ortopédicamente con halo-chaleco. Se estudiaron retrospectivamente 18 pacientes que presentaron una fractura de odontoides y que fueron tratadas en el período 1987-2001 mediante halo-chaleco. La edad media fue de 38 años (rango 16-75 años). El seguimiento medio fue de 5 años (rango 1-15 años). El mecanismo lesional más frecuente fue, en 11 casos, el accidente de tráfico. Según la clasificación de Anderson y D’Alonzo, en 8 casos la fractura fue del tipo III y en 10 casos del tipo II. En todos los casos se realizó un estudio radiográfico estándar y mediante tomografía axial computarizada (TAC) (excepto en 3 casos). La consolidación se documentó mediante radiografía y tomografía simple (en algunos casos mediante TAC). Según la escala de Smiley-Webster, se evaluó: el dolor, la movilidad cervical, el retorno a la actividad y la situación neurológica. La tasa global de consolidación fue del 89% (16 casos). En 9 casos se obtuvieron resultados excelentes (50%); en 4, buenos (22,2%); en 3, regulares (16,6%); y en 2, malos (11,1%). Se obtuvieron buenos resultados en 6 casos de fracturas del tipo II (60%) y en 7 casos del tipo III (87,5%). En 7 casos se consiguió mejorar la reducción una media de 6 mm. En 2 casos el desplazamiento inicial hasta la consolidación aumentó 2 mm. Los malos resultados, por fracaso del tratamiento, precisaron de artrodesis cervical posterior mediante la técnica de Brooks y Gallie (11,1%). En 2 de los cinco pacientes mayores de 60 años (40%) fracasó el tratamiento y se precisó de intervención quirúrgica para estabilizar la fractura. Entre las complicaciones más importantes destacaron 5 casos de aflojamiento del halo (27,7%), un caso de neuroma sensitivo y un caso de siringomielia postraumática secundaria. El tratamiento ortopédico con halo-chaleco nos ha permitido reducir y estabilizar la fractura de odontoides hasta la consolidación en el 89% de los casos, obteniendo un 66,5% de buenos resultados.

Surgical Treatment of Dens Fractures in Elderly Patients

A dens fracture is the most common cervical fracture in elderly patients. The purposes of this study were to analyze the functional and radiographic results after surgical treatment of dens fractures in patients over sixty-five years of age and to compare the two methods that were used for operative treatment. We reviewed the cases of fifty-six patients, with an average age of 71.4 years at the time of surgery, who had undergone surgical treatment of a dens fracture from 1988 to 2002. Thirty-seven fractures were stabilized with anterior screw fixation, and nineteen fractures had posterior cervical arthrodesis. Forty-five patients returned to their preinjury activity level and were satisfied with their treatment. Thirty-five patients had a full range of neck movement, and forty-seven patients were free of pain. Technical failures occurred in eight patients. The thirty-seven patients treated with anterior screw fixation had a good clinical outcome, with fracture-healing in thirty-three patients (89%) and technical failure in five patients (14%). All nineteen patients treated with posterior cervical arthrodesis had fracture union, with technical failure in three patients, but the functional results were worse than those after anterior screw fixation. With the inclusion of the six patients who had been excluded from the clinical and radiographic review, the overall morbidity rate was 16% (ten of sixty-two patients) and the overall mortality rate was 6% (four of sixty-two patients). A satisfactory outcome can be achieved with surgical treatment of a dens fracture in geriatric patients. It appears that anterior screw fixation may maintain better mobility of the cervical spine, but it appears to be associated with a higher rate of fracture nonunion and a greater potential for reoperation.

Posterior cervical spine arthrodesis with laminar screws: a report of two cases.

We performed fixation using laminar screws in 2 patients in whom lateral mass screws, pedicle screws or transarticular screws could not be inserted. One was a 56-year-old woman who had anterior atlantoaxial subluxation (AAS). When a guide wire was inserted using an imaging guide, the hole bled massively. We thought the re-insertion of a guide wire or screw would thus increase the risk of vascular injury, so we used laminar screws. The other case was an 18-year-old man who had a hangman fracture. Preoperative magnetic resonance angiography showed occlusion of the left vertebral artery. A laminar screw was inserted into the patent side (i.e., the right side of C2). Cervical pedicle screws are the most biomechanically stable screws. However, their use carries a high risk of neurovascular complications during screw insertion, because the cervical pedicle is small and is adjacent laterally to the vertebral artery, medially to the spinal cord, and vertically to the nerve roots. Lateral mass screws are also reported to involve a risk of neurovascular injuries. The laminar screw method was thus thought to be useful, since arterial injuries could thus be avoided and it could also be used as a salvage modality for the previous misinsertion.

Posterior Cervical Arthrodesis for Subacute Odontoid Fracture in a Patient With Osteopetrosis

A case of subacute odontoid fracture in a patient with osteopetrosis treated with posterior cervical arthrodesis using transarticular screws and interspinous wiring. To report the first successful cervical arthrodesis in a patient with osteopetrosis and to highlight the potential perioperative pitfalls in this rare surgical population. Osteopetrosis is a group of skeletal dysplasias characterized by osteoclast dysfunction, impaired bone resorption, and poor bone remodeling. Unique challenges associated with surgical fixation in osteopetrotic bone include a high incidence of nonunion, intraoperative fractures, intraoperative instrumentation failure, infection, and prosthesis loosening. We report the case of a patient with a subacute odontoid fracture treated successfully with posterior cervical arthrodesis using transarticular screws and interspinous wiring. The surgical technique, intraoperative pitfalls, and 2-year follow-up data are reported. The patient underwent a successful posterior cervical arthrodesis using transarticular screws and interspinous wiring with autogenous iliac crest graft. At 2 years, a stable fixation was achieved with only mild postoperative limitation in neck range of motion. Cervical fractures and instability that require surgery in patients with osteopetrosis represent a unique challenge to the orthopedic spine surgeon. Despite the increased potential for perioperative instrumentation complications, nonunion, and infection, posterior cervical arthrodesis can be achieved and should be considered in the treatment armamentarium for this potentially catastrophic injury.

Long-term incidence of subaxial cervical spine instability following cervical arthrodesis surgery in patients with rheumatoid arthritis

Cervical spine deformities are well-known complications of RA. A 5- to 20-year follow-up of 51 consecutive rheumatoid patients who underwent posterior cervical arthrodesis is presented to evaluate the recurrence of instability and need for further surgery. We conducted a retrospective review of the clinical features of 11 men and 40 women with an established diagnosis of RA and associated cervical deformities who underwent cervical spine surgery at the Mayo Clinic (Rochester, MN) between 1979 and 1990. Their mean age was 61 +/- 10 years (SD), and their duration of RA averaged 21 +/- 8.9 years (SD). There were 22 patients who presented with myelopathy, 7 with radiculopathy, and 22 with instability/neck pain. There were 33 patients with AAS, 2 with SMO process into the foramen magnum, 8 with SAS, and 8 with combinations of these. Preoperative reduction was followed by decompression and fusion using wiring techniques and autologous bone graft. Postoperative halo orthosis was provided for at least 3 months. The mean follow-up was 8.3 +/- 6 years (SD). There were 31 patients (61%) who underwent atlantoaxial arthrodesis, 17 patients (33%) who underwent subaxial, and 3 patients (6%) who underwent occipitocervical arthrodesis. During follow-up, 39% (13/33) of patients with AAS developed nonsymptomatic (6) or symptomatic/unstable (7) SASs subsequent to C1-C2 fusion. The latter 7 patients (21%) subsequently required extension of their arthrodesis. Adjacent segment disease was most common at the C3-C4 interspace after atlantoaxial fusion in 62% (8/13). Among the 8 patients who underwent isolated cervical fusion for SAS, 1 patient (1/8, 12%) developed adjacent instability after a fall and required extension of the previous fusion. No secondary procedure was required for the 6 patients initially stabilized by C1-(C6-T1) fusions for combinations of AAS + SAS. None of the patients initially treated by C1-C2 arthrodesis for AAS progressed to SMO. The incidence of subaxial instability in patients with rheumatoid disease who underwent cervical arthrodesis may be higher than previously reported, indicating the need for continued follow-up in these patients. Adjacent segment disease may be most common at the C3-C4 level following atlantoaxial fusion. Early stabilization of the C1-C2 complex in the patients with AAS may potentially prevent progression of SMO.

Posterior cervical fixation using a new polyaxial screw and rod system: technique and surgical results

Standard lateral mass plate and screw systems are of limited use in patients with abnormal cervical anatomy and do not easily allow for extension to either the occipit or the thoracic spine. The objective of this study was to demonstrate the safety, surgical efficacy, and advantages of a new cervical polyaxial screw and rod system for posterior occipitocervicothoracic arthrodesis. The authors reviewed a multicenter series of patients who underwent surgery in which they used a new posterior cervical polyaxial screw and rod system. The system was implanted in 32 (20 women and 12 men) adult patients (mean age 56.9 years, range 23-84 years). Twenty-three of the patients were treated for spondylostenosis; four for cervical fracture/dislocations; four for kyphosis; and one patient was treated for pseudarthrosis that developed after prior surgery. The system was successfully implanted in all patients despite the presence of anatomical lateral mass anomalies in the majority of cases. The mean number of levels fused was 3.9 (range one-eight levels). This dynamic system allowed for screw placement into the occiput, C-1 lateral masses, C-2 pars, C3-7 lateral masses, and low cervical as well as upper thoracic pedicles. Selective application of compressive or distractive forces was possible in adjacent segments. Surgery-related complications included one dural tear and one malpositioned screw. There were two cases of wound infection. Unlike standard lateral mass plate and screw systems, the new cervical polyaxial screw and rod system easily accommodates severe degenerative cervical spondylosis and curvatures. This instrumentation system allows for polyaxial screw placement with subsequent multiplanar rod contouring and offset attachment. The authors have used this system successfully, and without significant complications, to achieve posterior cervical arthrodesis.