Improving C1-C2 Complex Fusion Rates: An Alternate Approach.

The surgical repair of atlantoaxial instabilities (AAI) presents complex and unique challenges, originating from abnormalities and/or trauma within the junction regions of the C1-C2 atlas-axis, to surgeons. When this region is destabilized, surgical fusion becomes of key importance in order to prevent spinal cord injury. Several techniques can be utilized to provide for the adequate fusion of the atlantoaxial construct. Nevertheless, many individuals have less than ideal rates of fusion, below 35%-40%, which also involves the C2 nerve root being sacrificed. This suboptimal and unavoidable iatrogenic complication results in the elevated probability of complications typically composed of vertebral artery injury. This review is a retrospective analysis of 87 patients from Cedars Sinai Medical Center in Los Angeles, California, who had the C1-C2 surgical fusion procedure performed within the time frame from 2001 to 2008, with a mean follow-up period of three years. These patients had presented with typical AAI symptoms of fatigability, limited mobility, and clumsiness. Diagnosis of C1-C2 instability was documented via radiographic studies, typically utilizing computed tomography (CT) scans or x-rays. All patients had bilateral C1 lateral masses and C2 pedicle screws. In addition, the C1-C2 joint was accessed by retracting the C2 nerve root superiorly and exposing the joint by utilizing a high-speed burr. The cavity that is developed within the joint is packed with local autologous bone from the cephalad resection of the C2 laminae. Fusion of the C1-C2 joint was achieved in all patients and a final follow-up was conducted approximately three years postoperative. Of the 87 patients, two presented with occipital headaches resulting from the C1 screws impinging on the C2 nerve root. The issue was rectified by removing instrumentation in both patients after documenting complete fusion via radiographic studies, with complete resolution of symptoms. No vertebral artery or spinal cord injuries were reported as a result of the minor complication. Overall, we aim to describe a safe and reliable alternative technique to fuse C1-C2 instability by focusing on intra-articular arthrodesis complementing instrumentation fixation. This methodology is advantageous from a biomechanical standpoint secondary to axial loading, as well as the large surface area available for arthrodesis. Additionally, this technique does not involve the resection of the C2 nerve root, resulting in low risk for vertebral artery or spinal cord injury.

Image-guided thoracoscopic resection of thoracic dumbbell nerve sheath tumors.

BACKGROUND: Surgical removal of dumbbell nerve sheath tumors (NSTs) remains challenging because these neoplasms occupy ≥ 2 spinal and extraspinal spaces. The presence of intraspinal extension, tumor dimension, and/or its location within the thoracic cavity have previously made the resection of these types of neoplasms difficult. OBJECTIVE: To describe the feasibility of performing minimally invasive thoracoscopic surgery, as facilitated by an image guidance system (IGS), to achieve gross total resection of select dumbbell NSTs located in the thoracic spine. METHODS: The 3 cases presented here contained small intraspinal or foraminal components. Preoperative symptoms included Horner syndrome and back and chest wall pain. We used IGS to help guide the complete thoracoscopic resection of select dumbbell NSTs, consisting of extradural, intraforaminal, and paravertebral tumor components, which previously would have been challenging with only a thoracoscopic approach. RESULTS: IGS provided continuous intraoperative anatomic orientation to achieve gross total resection in all 3 cases. All surgical and postsurgical outcomes were satisfactory; preoperative symptoms improved or resolved; and no adverse events were observed. CONCLUSION: Thoracic dumbbell NSTs that have small intraspinal or foraminal components could be resected thoracoscopically when facilitated by IGS. Image-guided thoracoscopic resection of such dumbbell tumors may not only improve the precision of resection, reduce recurrence, and avoid the need for spinal reconstruction but also obviate the need for more invasive or simultaneous posterior procedures. The IGS enhances the accuracy and safety of 2-dimensional thoracoscopic surgery and may reduce its learning curve.

Cervicothoracic junction kyphosis: surgical reconstruction with pedicle subtraction osteotomy and Smith-Petersen osteotomy. Presented at the 2009 Joint Spine Section Meeting. Clinical article.

OBJECT: Sagittal plane deformities can be subdivided into kyphotic and lordotic forms and further characterized according to their global or regional (focal) presentation. Regional deformities of a significant magnitude constitute a gibbous deformity. Pedicle subtraction osteotomy (PSO) and interlaminar Smith-Petersen osteotomies have been used to correct sagittal plane deformities in the cervical, thoracic, and lumbar spine. By resecting a portion of the vertebral body and closing in the gap of this vertebra, the spine is placed in local lordosis and kyphosis is corrected. These osteotomies have generally been carried out in the lumbar or less frequently in the thoracic area. While PSO has been performed in the mid and lower thoracic spine, there have been no case series of patients undergoing PSO at the CTJ. Specifically, a PSO approach that addresses the challenges of the CTJ is needed. Here, the authors review their case series of PSOs performed in the CTJ. Their goal in the treatment of these patients was to correct the regional CTJ kyphosis, restore forward gaze, and reduce the pain associated with the deformity. METHODS: Eight patients (5 males and 3 females, mean age 63 years) underwent PSO for the correction of CTJ kyphosis. Pedicle subtraction osteotomy was performed at C-7 or the upper thoracic vertebrae and was facilitated by a computer-guided intraoperative monitoring system. Surgical indications included postlaminectomy kyphosis, spinal cord tumor resection, posttraumatic kyphosis, and degenerative cervical spondylosis. RESULTS: The mean follow-up was 15.3 months (range 12-20 months), and the mean preoperative CTJ kyphosis was 38.67° (range 25°-60°). Clinically satisfactory correction of the regional deformity was accomplished in all patients, achieving a mean correction of 35.63° (range 15°-66°) at the CTJ, with restoration of forward gaze and significant reduction in pain. CONCLUSIONS: A CTJ deformity is a distinctive form of kyphosis that presents as a variable local deformity and requires complex spinal reconstructive techniques to restore sagittal balance and forward gaze. Pedicle subtraction osteotomy allows for significant correction through one spinal segment, and it can be used safely to correct the regional sagittal alignment of the cervical spine and head in relation to the pelvis. Pedicle subtraction osteotomy can be used alone or in combination with other techniques as some patients may require multistage procedures with anterior and posterior spinal reconstruction to obtain stable sagittal correction. All deformities in these patients were kyphotic in nature with only mild elements of scoliosis or coronal plane deformity. This is unlike lumbar and thoracic curves where the kyphosis is frequently associated with scoliosis.

The rare case of an intramedullary cervical spinal cord teratoma in an elderly adult: case report and literature review.

STUDY DESIGN.: Case report and literature review. OBJECTIVES.: To report the very rare case of a mature intramedullary teratoma with exophytic extension localized to the uppermost cervical spinal level in a 65-year-old woman and review the pertinent medical literature. SUMMARY OF BACKGROUND DATA.: Cervical intramedullary teratomas are extremely rare in adults, especially in patients older than 50 years. METHODS.: The patient presented with progressive ataxia, mild bilateral kinetic hand tremors, and dizziness. Magnetic resonance imaging revealed an intramedullary 1.7 x 1.3 x 2.3 cm mass at C1 with exophytic extension. A C1-C2 laminectomy and a partial suboccipital craniotomy were performed, followed by a subtotal microscopic resection of the tumor. Pathology was consistent with a mature teratoma. RESULTS.: After surgery, the patient's ataxia, tremor, and dizziness resolved almost immediately. CONCLUSION.: This report presents the very rare case of a mature intramedullary teratoma located in the upper cervical spine of an elderly patient, possibly the oldest patient documented with this type of lesion. The authors recommend a conservative subtotal surgical resection of cervical intramedullary tumors because it may improve symptoms that relate to direct mechanical cord compression and avoid further harm from a gross resection.

An intensive, progressive exercise program reduces disability and improves functional performance in patients after single-level lumbar microdiskectomy.

BACKGROUND: Restoration of physical function following lumbar microdiskectomy may be influenced by the postoperative care provided. OBJECTIVE: The purpose of this study was to examine the effectiveness of a new interventional protocol to improve functional performance in patients who have undergone a single-level lumbar microdiskectomy. SETTING: The study was conducted in physical therapy outpatient clinics. DESIGN AND PARTICIPANTS: Ninety-eight participants (53 male, 45 female) who had undergone a single-level lumbar microdiskectomy were randomly allocated to receive education only or exercise and education. INTERVENTION AND MEASUREMENTS: The exercise intervention consisted of a 12-week periodized program of back extensor strength (force-generating capacity) and endurance training and mat and upright therapeutic exercises. The Oswestry Disability Index (ODI) and physical measures of functional performance were tested 4 to 6 weeks postsurgery and 12 weeks later, following completion of the intervention program. Because some participants sought physical therapy outside of the study, postintervention scores were analyzed for both an as-randomized (2-group) design and an as-treated (3-group) design. RESULTS: In the 2-group analyses, exercise and education resulted in a greater reduction in ODI scores and a greater improvement in distance walked. In the 3-group analyses, post hoc comparisons showed a significantly greater reduction in ODI scores following exercise and education compared with the education-only and usual physical therapy groups. LIMITATIONS: The limitations of this study include a lack of adherence to group assignment, disproportionate therapist contact time among treatment groups, and multiple use of univariate analyses. CONCLUSIONS: An intensive, progressive exercise program combined with education reduces disability and improves function in patients who have undergone a single-level lumbar microdiskectomy.

Topical hemostatic agents in surgery: a surgeon's perspective.

Good hemostasis in surgery can provide multiple advantages to the patient, surgical team, and health care facility. Active and passive hemostatic agents have been widely used for many years and have extensive history supporting effective and safe use in a wide variety of surgical procedures. The type of surgical procedure, type of bleeding, hemostatic agent availability, and patient characteristics will influence the choice of topical hemostatic agent that is used by the surgeon. By actively participating in the coagulation cascade, active topical hemostatic agents are more able to meet the criteria of an ideal hemostatic agent in cases of oozing blood and minor bleeding during surgical procedures. Active agents can be used alone or in combination with passive agents. Familiarity with the products used to achieve hemostasis and their preparation can facilitate optimal use by surgical teams.

Microvascular decompression for intractable singultus: technical case report.

OBJECTIVE: Intractable singultus is a rare but significantly disruptive clinical phenomenon that often accompanies other diseases but can present in isolation due entirely to intracranial pathology. We report a case of intractable singultus that improved after microvascular decompression and present a comprehensive review of singultus by discussing its similarity to other cases of microvascular decompression, its history and etiology, and its evolutionary basis. CLINICAL PRESENTATION: The patient exhibited intractable singultus for 15 years, resistant to multiple medical regimens. INTERVENTION: Microvascular decompression to relieve pressure on the tenth cranial nerve and medulla oblongata resulted in near total resolution of the singultus. CONCLUSION: Neurovascular compression should be considered a potentially reversible cause of intractable singultus, a significantly disabling clinical phenomenon.

Risk of bleeding in surgical patients treated with topical bovine thrombin sealants: a review of the literature.

BACKGROUND: One of the most anticipated, but potentially serious complications during or after surgery are bleeding events. Among the many potential factors associated with bleeding complications in surgery, the use of bovine thrombin has been anecdotally identified as a possible cause of increased bleeding risk. Most of these reports of bleeding events in association with the use of topical bovine thrombin have been limited to case reports lacking clear cause and effect relationship determination. Recent studies have failed to establish significant differences in the rates of bleeding events between those treated with bovine thrombin and those treated with either human or recombinant thrombin. METHODS: We conducted a search of MEDLINE for the most recent past 10 years (1997-2007) and identified all published studies that reported a study of surgical patients with a clear objective to examine the risk of bleeding events in surgical patients. We also specifically noted the reporting of any topical bovine thrombin used during surgical procedures. We aimed to examine whether there were any differences in the risk of bleeds in general surgical populations as compared to those studies that reported exposure to topical bovine thrombin. RESULTS: We identified 21 clinical studies that addressed the risk of bleeding in surgery. Of these, 5 studies analyzed the use of bovine thrombin sealants in surgical patients. There were no standardized definitions for bleeding events employed across these studies. The rates of bleeds in the general surgery studies ranged from 0.1%-20.2%, with most studies reporting rates between 2.6%-4%. The rates of bleeding events ranged from 0.0%-13% in the bovine thrombin studies with most studies reporting between a 2%-3% rate. CONCLUSION: The risk of bleeds was not clearly different in those studies reporting use of bovine thrombin in all patients compared to the other surgical populations studied. A well-designed and well-controlled study is needed to accurately examine the bleeding risks in surgical patients treated and unexposed to topical bovine thrombin, and to evaluate the independent risk associated with topical bovine thrombin as well as other risk factors.

Cadaveric morphometric analysis for atlantal lateral mass screw placement.

OBJECTIVE: Atlantal lateral mass screws provide an alternative to C1/C2 transarticular screws and, in some cases, can obviate the need for extending a fusion to the occiput. For these reasons, C1 lateral mass screws are becoming increasingly popular. However, the critical local anatomy and unfamiliarity with this new technique can make C1 screw placement more challenging. METHODS: Morphometric analysis was performed on 74 cadaveric spines obtained from the Department of Anatomy at the Keck School of Medicine, University of Southern California. Critical measurements were determined for screw entry points, trajectories, and lengths for application of the technique described by Harms and Melcher. RESULTS: The mean height and width for screw entry on the posterior surface of the lateral mass were 3.9 and 7.3 mm, respectively. The maximum medialized screw trajectory ranged from 25 to 45 degrees (mean, 33 degrees). The mean maximal screw length to obtain bicortical purchase was 22.5 mm, and the mean minimum screw depth was 14.4 mm. Screw depths varied on the basis of the entry point, trajectory, and vertebral morphology. The overhang of the posterior arch averaged 11.4 mm (range, 6.9-17 mm). All specimens could accommodate 3.5-mm lateral mass screws bilaterally with proper preparation of the entry site. CONCLUSION: Significant variations in the morphology of C1 exist. However, the large size of the atlantal lateral mass makes screw placement forgiving. Preoperative computed tomographic scans and intraoperative fluoroscopy are useful in guiding proper screw placement. Close attention should be paid to preparation of the screw entry site.