An Anatomical Method for Rib Disconnection During Posterior Costotransversectomy for Paravertebral Access to the Ventral Thoracic Spine.

OBJECTIVE: Posterior costotransversectomy in the thoracic spine is commonly used for degenerative diseases, tumors, trauma, and other operative indications. It involves resection of the rib head after the ligamentous complexes have been disconnected from the transverse process and lateral vertebral body. The current literature provides only vague descriptions of the steps involved in rib disconnection with respect to posterior costotransversectomy. METHODS AND RESULTS: Through cadaveric studies and in vivo application, a stepwise method for rib disconnection is described. CONCLUSIONS: This manuscript is the first to outline an anatomical method for rib disconnection during costotransversectomy.

Prospective Evaluation of Radiculitis following Bone Morphogenetic Protein-2 Use for Transforaminal Interbody Arthrodesis in Spine Surgery.

Study Design: Prospective observational cohort study. Purpose: This study aims to evaluate the safety and efficacy of bone morphogenetic protein-2 (BMP-2) in transforaminal lumbar interbody fusion (TLIF) with regard to postoperative radiculitis. Overview of Literature: Bone morphogenetic protein (BMP) is being used increasingly as an alternative to iliac crest autograft in spinal arthrodesis. Recently, the use of BMP in TLIF has been examined, but concerns exist that the placement of BMP close to the nerve roots may cause postoperative radiculitis. Furthermore, prospective studies regarding the use of BMP in TLIF are lacking. Methods: This prospective study included 77 patients. The use of BMP-2 was determined individually, and demographic and operative characteristics were recorded. Leg pain was assessed using the Visual Analog Scale (VAS) for pain and the Sciatica Bothersome Index (SBI) with several secondary outcome measures. The outcome data were collected at each follow-up visit. Results: Among the 77 patients, 29 were administered with BMP. Postoperative leg pain significantly improved according to VAS leg and SBI scores for the entire cohort, and no clinically significant differences were observed between the BMP and control groups. The VAS back, Oswestry Disability Index, and Short-Form 36 scores also significantly improved. A significantly increased 6-month fusion rate was noted in the BMP group (82.8% vs. 55.3%), but no significant differences in fusion rate were observed at the 12- and 24-month follow-up. Heterotopic ossification was observed in seven patients: six patients and one patient in the BMP and control groups, respectively (20.7% vs. 2.1%). However, no clinical effect was observed. Conclusions: In this prospective observational trial, the use of BMP in TLIF did not lead to significant postoperative radiculitis, as measured by VAS leg and SBI scores. Back pain and other functional outcome scores also improved, and no differences existed between the BMP and control groups. The careful use of BMP in TLIF appears to be both safe and effective.

Idiopathic localizing signs and atypical symptoms of cervical disk pathology: A case report.

Cervical disc herniations most often present with neck and arm pain resulting from direct nerve root compression from a paramedian or foraminal disc herniation. It is unusual to encounter unilateral lower extremity symptoms in the absence of other neurological symptoms due to a centrally herniated cervical disc. Because this clinical presentation is uncommon, there can be misdiagnosis, or delay in treatment of patients who suffer from debilitating pain or weakness. We treated a patient who presented with acute progressive unilateral lower extremity weakness and paresthesia from a large herniated cervical disk. His lower extremity symptoms resolved post-operatively after undergoing anterior cervical discectomy and fusion. This case provides an example of the importance of neuroanatomical knowledge in surgical decision-making; clinicians should recognize that unilateral leg weakness can result from cervical disc herniation in absence of other neurological symptoms.

Prognostic factors and survival in low grade gliomas of the spinal cord: A population-based analysis from 2006 to 2012.

PURPOSE: Primary spinal cord tumors are rare, and evidence-based management of these patients remains a source of controversy. This study used a large cohort of low-grade spinal cord astrocytomas to determine the effectiveness of prognostic factors and survival. METHODS: The Surveillance, Epidemiology, and End Results (SEER) cancer registry was used to identify patients with WHO grade I-II primary spinal cord astrocytomas from 1973 to 2012; however, patients before 2006 were excluded due to ambiguity diagnosis. Univariate and multivariate Cox proportional hazard models were created to compare survival across covariates and summarized using the Kaplan-Meier method. RESULTS: A total of 561 patients with low-grade glioma (astrocytoma) were identified. Among these, 15.5% of patients received a gross total resection (GTR), 26.1% subtotal resection (STR), and 46.2% unidentified extent of resection. 59.4% did not receive any radiation therapy at any point of the treatment course, while 40.6% underwent radiation therapy. In our cohort, only patients with GTR demonstrated statistically improved survival (HR: 0.22, P < 0.001). Patients with STR had nearly identical survival compared to patients with no surgery (HR: 0.98), and radiotherapy was associated with increased odds of mortality (HR: 1.47, P < 0.001). Multivariate analysis demonstrated a significant survival benefit among patients with younger age, GTR and absence of radiotherapy. Histologic grade did not statistically impact survival. CONCLUSION: Our study suggests that GTR results in improved survival among patients with low-grade gliomas within the spinal cord. Future, considerable data research efforts will aim to better define the role of radiotherapy and tumor grading in this patient population.

Challenges of Managing Patients with Symptomatic Large Traumatic Cervical Pseudomeningoceles.

BACKGROUND: Traumatic cervical pseudomeningoceles (TCPs) occur secondary to traction of the cervical nerve roots resulting in violation of the dura. Surgical repair is not necessary in most cases because pseudomeningoceles have a high propensity to spontaneously resolve with conservative management alone. Currently, there are a limited number of cases of large TCPs (large is defined as ≥6 cm in greatest diameter), and there is no established guideline for the management of such lesions. CASE DESCRIPTION: We describe the cases of 2 young men in their 20s who were involved in a motor vehicle accident. Both patients suffered a brachial plexus injury and developed large TCPs. Patient 1 was treated surgically for TCP using a combined intra-/extradural approach using a fascia lata graft. Patient 2 was ultimately treated nonsurgically because a spontaneous resolution of the pseudomeningocele was achieved over the period of 7 months after the accident. Both patients underwent brachial plexus repair surgery consisting of spinal accessory nerve transfer to the suprascapular nerve and intercostal nerve transfer to the musculocutaneous nerve. CONCLUSIONS: Disease progression of TCPs is a dynamic process, and even large lesions may spontaneously resolve without surgical intervention. When surgery is indicated, a definitive dural repair using a fascia lata graft to cover the dural tear intra- and extradurally is an effective method. Surgery must be planned carefully on a case-by-case basis, and close follow-up with thorough physical examination and serial imaging is critical to monitor disease progression.

Total lumbar facetectomy without fusion: short and long term follow-up in a single surgeon series.

BACKGROUND: Total lumbar facetectomy may be advantageous for exposure or to completely free a constricted nerve root. OBJECTIVE: We retrospectively reviewed a single surgeon series without fusion for short and long term outcomes regarding radicular pain relief, subsequent relevant surgeries, and any identifiable instability. METHODS: All operations in which a single, total lumbar facetectomy was performed were reviewed. A total of 222 patients were identified with a minimal follow-up of 3 months; 187 (84.2%) were available for long term follow-up ≥1 year by continued accessible health care records, correspondence, or mailed questionnaire. RESULTS: Short term success (3-month follow-up) for radicular pain relief in 222 patients found the following results: 176 patients (79.3%) had no pain or minimal pain, and 16 patients (7.2%) were improved, and thus resulting in 192 (86.5%) with no pain, or improved radicular pain. 30 patients (13.5%) were postoperative failures at 3 months. Long term follow-up ≥1 year was available for 187 patients (84.2%); (range 1-17 years; mean 7 years); found the following results: 23/30 (76.6%) short term surgical failures remained failures in long term follow-up with (7 patients) or without (16 patients) further surgery of any kind; 13/16 improved patients at long term follow-up remained improved (6), were pain free (6), or worse (1); 19/151 no or minimal pain patients at long term follow-up recurred or worsened by 1 year or longer, 12/19 pursued a second surgery with (9) or without (4) fusion and many improved. A total of 13 patients had a subsequent fusion operation (6.95%). DISCUSSION: Most patients do well in the short term for radicular pain relief. Most patients continue to do well in long term follow-up. Surgically induced clinical instability is uncommon in this highly selected series.

Comparison of Cervical Range-of-Motion Restriction and Craniofacial Tissue-Interface Pressure With 2 Adjustable and 2 Standard Cervical Collars.

STUDY DESIGN: Randomized controlled trial. OBJECTIVE: The aim of the study was to compare and contrast the restrictiveness and tissue-interface pressure (TIP) characteristics of 2 standard and 2 adjustable cervical collars. SUMMARY OF BACKGROUND DATA: This study compared the restrictiveness and TIP of 4 commercially available cervical collars (2 standard and 2 adjustable). Adjustable collars offer potential advantages of individualized fit for patients and decreased inventory for institutions. The overall goal was to determine whether the adjustable collars provided the same benefits of cervical range-of-motion (CROM) restriction as the standard collars without increasing TIP and risk of pressure-related complications. METHODS: A total of 48 adult volunteer subjects (24 men and 24 women) were fitted with 4 collars (Aspen, Aspen Vista, Miami J, and Miami J Advanced) in random order. Data collection included assessment of CROM restrictiveness and measurement of TIP on the mandible and occiput in upright and supine positions. The experimental, repeated measures design stratified the sample by body mass index (BMI) and sex. RESULTS: All collars restricted CROM as compared with no collar (P ≤ 0.001 each). Aspen was more restrictive than Aspen Vista and Miami J in 4 movement planes (P ≤ 0.003 each), but not significantly different from Miami J Advanced. The Miami J standard collar was associated with significantly lower peak TIPs on all sites and in all positions compared with Aspen (P ≤ 0.001), Miami J Advanced (P < 0.001), and Aspen Vista (P = 0.01 for mandible site and upright position, P < 0.001 for remaining sites and positions). Increased peak TIP correlated with high BMI across all collar types, but was significantly lower for the Miami J collar than the Aspen collar. CONCLUSION: All collars, compared with no collar, significantly restricted CROM. Although the collar-to-collar comparisons were statistically significant, the differences may have little clinical significance in the acutely injured trauma patient. The Miami J standard collar had the lowest overall TIP in both sites and positions. Ongoing effort should be devoted to staff education in proper sizing and fit, particularly for patients with high BMI.

In-hospital neurologic deterioration following fractures of the ankylosed spine: a single-institution experience.

OBJECTIVE: To determine the rate and severity of in-hospital neurologic deterioration following vertebral fractures of spinal hyperostosis. METHODS: A retrospective review of 92 fractures in 81 patients with diffuse idiopathic skeletal hyperostosis (42%) or ankylosing spondylitis (58%) was performed. Data on demographics, comorbidities, and fracture and treatment characteristics were recorded. Neurologic presentation and outcomes were categorized using American Spinal Injury Association grades and the modified Rankin Scale. Univariate and multivariate analyses were used to identify risk factors for neurologic deterioration or poor outcome (modified Rankin Scale 4-6). RESULTS: Most fractures (66%) occurred after falls of standing height or less. Presentation was delayed in 41% of patients (median 7 days), and diagnosis was delayed in 21% (median 8 days). Most fractures were extension (60%) or distraction (78%) injuries involving all 3 spinal columns. Median Subaxial Cervical Spine Injury Classification and Thoracolumbar Injury Severity Scale scores were 6 (interquartile range 5-7) and 7 (interquartile range 6-8), respectively. Of patients, 62% underwent open operative fusion either as initial therapy or after failed conservative treatment, 20% had percutaneous instrumentation, and 27% were treated in an external orthosis (52% required open fusion). Neurologic deterioration after presentation occurred in 7 patients (8.6%); 5 of these patients deteriorated after surgical treatment, constituting a 7.6% surgical risk. The presenting American Spinal Injury Association grade and patient age predicted poor outcome at 1-year outcome (P < 0.001). Death occurred in 17 patients within 1 year of injury (23%). CONCLUSIONS: Neurologic deterioration during the initial hospitalization after spinal fractures in the setting of diffuse idiopathic skeletal hyperostosis or ankylosing spondylitis is common, and 1-year mortality is high.

Chiari 1 Malformation Presenting as Central Sleep Apnea during Pregnancy: A Case Report, Treatment Considerations, and Review of the Literature.

PURPOSE: Chiari malformation (CM) type-1 frequently causes obstructive or central sleep-disordered breathing (SDB) in both adults and children, although SDB is relatively rare as a presenting manifestation in the absence of other neurological symptoms. The definitive treatment of symptomatic CM is surgical decompression. We report a case that is, to our knowledge, a novel manifestation of central sleep apnea (CSA) due to CM type-1 with severe exacerbation and initial clinical presentation during pregnancy. METHODS: Case report from tertiary care comprehensive sleep medicine center with literature review of SDB manifestations associated with CM type-1. PubMed search was conducted between January 1982 and October 2013. RESULTS: We report a 25-year-old woman with severe CSA initially presenting during her first pregnancy that eventually proved to be caused by CM type-1. The patient was successfully treated preoperatively by adaptive servoventilation (ASV), with effective resolution of SDB following surgical decompression, and without recurrence in a subsequent pregnancy. Our literature review found that 58% of CM patients with SDB had OSA alone, 28% had CSA alone, 8 (10%) had mixed OSA/CSA, and 6 (8%) had hypoventilation. Of CM patients presenting with SDB, 50% had OSA, 42% had CSA, 8% had mixed OSA/CSA, and 10.4% had hypoventilation. We speculate that CSA may develop in CM patients in whom brainstem compression results in excessive central chemoreflex sensitivity with consequent hypocapnic CSA. CONCLUSION: Chiari malformation type-1 may present with a diversity of SDB manifestations, and timely recognition and surgical referral are necessary to prevent further neurological deficits. ASV therapy can effectively manage CSA caused by CM type-1, which may initially present during pregnancy.

Migration to the ICD-10 coding system: A primer for spine surgeons (Part 1).

BACKGROUND: On 1 October 2015, a new federally mandated system goes into effect requiring the replacement of the International Classification of Disease-version 9-Clinical Modification (ICD-9-CM) with ICD-10-CM. These codes are required to be used for reimbursement and to substantiate medical necessity. ICD-10 is composite with as many as 141,000 codes, an increase of 712% when compared to ICD-9. METHODS: Execution of the ICD-10 system will require significant changes in the clinical administrative and hospital-based practices. Through the transition, diminished productivity and practice revenue can be anticipated, the impacts of which the spine surgeon can minimizeby appropriate education and planning. RESULTS: The advantages of the new system include increased clarity and more accurate definitions reflecting patient condition, information relevant to ambulatory and managed care encounters, expanded injury codes, laterality, specificity, precise data for safety and compliance reporting, data mining for research, and finally, enabling pay-for-performance programs. The disadvantages include the cost per physician, training administrative staff, revenue loss during the learning curve, confusion, the need to upgrade hardware along with software, and overall expense to the healthcare system. CONCLUSIONS: With the deadline rapidly approaching, gaps in implementation result in delayed billing, delayed or diminished reimbursements, and absence of quality and outcomes data. It is thereby essential for spine surgeons to understand their role in transitioning to this new environment. Part I of this article discusses the background, coding changes, and costs as well as reviews the salient features of ICD-10 in spine surgery.

Implementation and impact of ICD-10 (Part II).

BACKGROUND: The transition from the International Classification of Disease-9(th) clinical modification to the new ICD-10 was all set to occur on 1 October 2015. The American Medical Association has previously been successful in delaying the transition by over 10 years and has been able to further postpone its introduction to 2015. The new system will overcome many of the limitations present in the older version, thus paving the way to more accurate capture of clinical information. METHODS: The benefits of the new ICD-10 system include improved quality of care, potential cost savings, reduction of unpaid claims, and improved tracking of healthcare data. The areas where challenges will be evident include planning and implementation, the cost to transition, a shortage of qualified coders, training and education of the healthcare workforce, and a loss of productivity when this occurs. The impacts include substantial costs to the healthcare system, but the projected long-term savings and benefits will be significant. Improved fraud detection, accurate data entry, ability to analyze cost benefits with procedures, and enhanced quality outcome measures are the most significant beneficial factors with this change. RESULTS: The present Current Procedural Terminology and Healthcare Common Procedure Coding System code sets will be used for reporting ambulatory procedures in the same manner as they have been. ICD-10-PCS will replace ICD-9 procedure codes for inpatient hospital services. The ICD-10-CM will replace the clinical code sets. Our article will focus on the challenges to execution of an ICD change and strategies to minimize risk while transitioning to the new system. CONCLUSION: With the implementation deadline gradually approaching, spine surgery practices that include multidisciplinary health specialists have to anticipate and prepare for the ICD change in order to mitigate risk. Education and communication is the key to this process in spine practices.

Intraoperative image-guided spinal navigation: technical pitfalls and their avoidance.

Spinal instrumentation has made significant advances in the last two decades, with transpedicular constructs now widely used in spinal fixation. Pedicle screw constructs are routinely used in thoracolumbar-instrumented fusions, and in recent years, the cervical spine as well. Three-column fixations with pedicle screws provide the most rigid form of posterior stabilization. Surgical landmarks and fluoroscopy have been used routinely for pedicle screw insertion, but a number of studies reveal inaccuracies in placement using these conventional techniques (ranging from 10% to 50%). The ability to combine 3D imaging with intraoperative navigation systems has improved the accuracy and safety of pedicle screw placement, especially in more complex spinal deformities. However, in the authors' experience with image guidance in more than 1500 cases, several potential pitfalls have been identified while using intraoperative spinal navigation that could lead to suboptimal results. This article summarizes the authors' experience with these various pitfalls using spinal navigation, and gives practical tips on their avoidance and management.

L5-S1 extraforaminal intraneural disc herniation mimicking a malignant peripheral nerve sheath tumor.

BACKGROUND CONTEXT: An extraforaminal disc herniation may present as a retroperitoneal mass and is thus a differential diagnosis for a malignant lesion. PURPOSE: To highlight the difficulty in the accurate preoperative differentiation between an extraforaminal disc herniation and a malignant retroperitoneal mass despite the use of advanced anatomical and metabolic imaging. STUDY DESIGN: Case report. METHODS: The authors present a case of a 55-year-old man, with a family history of neurofibromatosis, who presented to us 2 months after the insidious occurrence of severe, unrelenting, right-sided, L5 dermatomal pain. He subsequently developed rapidly progressive motor weakness in the same myotome, which caused a foot drop. On examination, his straight-leg raise test was normal. Magnetic resonance imaging demonstrated a peripherally enhancing, complex, cystic mass continuous with the L5 nerve, displacing its fascicles medially, as it descended over the right sacral ala. A positron emission tomography scan demonstrated increased radiotracer uptake. The clinicoradiologic presentation was that of a malignant peripheral nerve sheath tumor. RESULTS: At surgery, an intraneural disc herniation was seen. CONCLUSIONS: Several pitfalls exist in establishing the uncommon diagnosis of an extraforaminal disc herniation. This entity occurs ventrally and must remain a consideration when elaborating the differential diagnosis of a retroperitoneal mass in close proximity to the vertebral column.

Superficial siderosis should be included in the differential diagnosis of motor neuron disease.

INTRODUCTION: Recent studies have revealed that some patients with superficial siderosis (SS) show evidence of an intraspinal fluid-filled collection on imaging. Some of these patients also show clinical and/or imaging features of craniospinal hypovolemia related to dural defects. We report a patient with SS whose clinical presentation was suggestive of motor neuron disease and whose history was remarkable for cerebrospinal fluid (CSF) hypovolemia. This report also reviews the literature on the relationship between SS, dural defects, and CSF hypovolemia. CASE REPORT: A 58-year-old left-handed man was evaluated for an 18-month history of progressive imbalance with limb muscle weakness, wasting, and fasciculations. Brain magnetic resonance imaging (MRI) studies were remarkable for evidence of SS and diffuse pachymeningeal enhancement similar to that seen in craniospinal hypovolemia. Spine MRI showed a longitudinal intraspinal fluid-filled collection. A dynamic computed tomographic myelogram of the spine showed a CSF leak adjacent to a peripherally calcified disk at the T2-3 level. Following repair of the dural defect the patient noted an improvement in balance and strength and resolution of the fasciculations. A cervical and thoracic spine MRI showed resolution of the intraspinal fluid-filled collection, and a CSF study showed no red blood cells or xanthochromia. CONCLUSIONS: The clinical spectrum of disorders related to dural defects includes craniospinal hypovolemia, SS-related ataxia and impaired hearing, segmental weakness and atrophy with or without hyperreflexia, and spinal cord herniation. The clinical features of these conditions may overlap. Longitudinally extensive ventral dissecting meningoceles can be seen in all these conditions. A dynamic computed tomographic myelogram can identify a dural defect. In some cases the dural defect may result from an osteophyte.

Synovial sarcoma of the spine: A report of three cases and review of the literature.

BACKGROUND: Synovial sarcoma (SS) is a rare sarcoma with distinct morphologic and genetic features, which, despite its name, does not arise from synovium. While most SSs (>80%) arise in the deep soft tissue of the extremities, up to 5% of these tumors are encountered in the body axis including the spine, mediastinum, retroperitoneum, and head/neck regions. Reports of SS located within the spinal axis have been rare to date. MATERIALS AND METHODS: We searched the medical records at our institution and found three patients who were diagnosed and treated for SSs involving the spine. We also performed an exhaustive literature search using PubMed to identify all reported cases in the literature. RESULTS: In this study, we report on three SS cases involving the spine. All three cases involved the paraspinal muscles and spinal nerve roots, with one case having a significant leptomeningeal involvement. In two cases, "smaller operations" were performed first because the lesions were thought to be benign, however, when the final pathology identified them as SSs, more radical procedures were performed. Additionally, we identified 14 cases of SSs involving the spine published in the literature and all cases are reviewed here. CONCLUSIONS: Due to limited numbers of cases, spine SS long-term outcomes are hard to quantify. The currently accepted standard of treatment for SSs starts with wide surgical excision with negative margins followed by chemotherapy and radiation. We summarize the available literature on spinal SSs and review the current treatment options available for these tumors.

Rheumatoid arthritis of the craniovertebral junction.

BACKGROUND: Rheumatoid arthritis (RA) is the most common inflammatory disease involving the spine. It has a predilection for involving the craniocervical spine. Despite widespread involvement of the cervical spine with RA, few patients need surgery. The 3 major spinal manifestations of RA in the cervical spine are basilar invagination, atlantoaxial instability, and subaxial subluxations. Surgical management of RA involving the craniovertebral junction remains a challenge despite a decline in severe cases and an improvement in surgical techniques. METHODS: We conducted an exhaustive review of English-language publications discussing RA involving the craniovertebral junction. We paid special attention to publications detailing modern surgical management of these conditions. In addition, we outline our own surgical experience with such patients. RESULTS: We discuss alternative surgical methods for treating basilar invagination, atlantoaxial instability, and concurrent subaxial subluxations. We detail our surgical technique for transoral odontoidectomy, occipital cervical fusion, and atlantoaxial fusion. We detail the use of spinal surgical navigation in both of these procedures. CONCLUSION: Surgical management of RA remains a challenging field. There clearly has been a decrease in cases of mutilating RA involving the craniovertebral junction. Surgical techniques for managing these conditions have steadily improved.

Can posterior-only surgery provide similar radiographic and clinical results as combined anterior (thoracotomy/thoracoabdominal)/posterior approaches for adult scoliosis?

STUDY DESIGN: Retrospective matched cohort analysis. OBJECTIVE: To determine if posterior-only (post-only) surgical techniques consisting of pedicle screws, osteotomies, transforaminal lumbar interbody fusion, and bone morphogenetic protein-2 may provide similar results as compared anterior (thoracotomy/thoracoabdominal)/posterior surgical approaches for the treatment of adult spinal deformity with respect to correction, fusion rates, or outcomes. SUMMARY OF BACKGROUND DATA: Combined anterior/posterior (A/P) fusion has traditionally been used to treat many adult scoliosis deformities. Anterior approaches negatively impact pulmonary function and require additional operative time and anesthesia. METHODS: Twenty-four patients who had A/P fusion for primary adult scoliosis (16 staged, 8 same-day) were matched with a cohort of 24 patients who had post-only treatment. Anterior fusion was performed via a thoracotomy (n = 1)/thoracoabdominal (n = 23) approach. All post-only surgeries were under one anesthesia. Minimum 2-year follow-up included radiographic, clinical, and outcomes data. RESULTS: There were no significant differences between groups for age, gender, diagnosis, comorbidities, preoperative curve magnitudes, or global balance. Postoperative radiographic correction and alignment were similar for both groups except for thoracolumbar curve percent improvement which was statistically better in the post-only group (P = 0.03). The average surgical time was higher in A/P versus post-only group (11.6 vs. 6.9 hours, P < 0.0001) as was total estimated blood loss (1330 vs. 980 mL, P = 0.04). Hospital length of stay (LOS) was longer in A/P versus post-only group (11.9 vs. 8.3 days, P = 0.03). There were no significant differences between postoperative complications. Revision surgery was performed in 5 A/P and 2 post-only patients. Higher pseudarthrosis rates found in the A/P versus post-only (17 vs. 0%) were not significant (P = 0.11). SRS-30 and Oswestry scores reflected a similar patient assessment before surgery, and improvement between groups at follow-up. CONCLUSION: Post-only adult scoliosis surgery achieved similar correction to A/P surgery while decreasing blood loss, operative time, length of stay, and avoiding additional anesthesia. Complications, radiographic, and clinical outcomes were similar at over 2-year follow-up.

Revision rates following primary adult spinal deformity surgery: six hundred forty-three consecutive patients followed-up to twenty-two years postoperative.

STUDY DESIGN: Retrospective study. OBJECTIVE: To analyze the prevalence of and reasons for unanticipated revision surgery in an adult spinal deformity population treated at one institution. SUMMARY OF BACKGROUND DATA: No recent studies exist that analyze the rate or reason for unanticipated revision surgery for adult spinal deformity patients over a long period. METHODS: All patients presenting for primary instrumented spinal fusion with a diagnosis of adult deformity at a single institution from 1985 to 2008 were reviewed using a prospectively acquired database. All surgical patients with instrumented fusion of > or =5 levels using hooks, hybrid, or screw-only constructs were identified. Patient charts and radiographs were reviewed to provide information as to the indication for initial and any subsequent reoperation. A total of 643 patients underwent primary instrumented fusion for a diagnosis of adult idiopathic scoliosis (n = 432), de novo degenerative scoliosis (n = 104), adult kyphotic disease (n = 63), or neuromuscular scoliosis (n = 45). The mean age was 37.9 years (range, 18-84). Mean follow-up for the entire cohort was 4.7 years, and 8.2 years for the subset of the cohort requiring reoperation (range, 1 month-22.3 years). RESULTS: A total of 58 of 643 patients (9.0%) underwent at least one revision surgery and 15 of 643 (2.3%) had more than one revision (mean 1.3; range, 1-3). The mean time to the first revision was 4.0 years (range, 1 week-19.7 years). The most common reasons for revision were pseudarthrosis (24/643 = 3.7%; 24/58 = 41.4%), curve progression (13/643 = 2.0%; 13/58 = 20.7%), infection (9/643 = 1.4%; 9/58 = 15.5%), and painful/prominent implants (4/643 = 0.6%; 4/58 = 6.9%). Uncommon reasons consisted of adjacent segment degeneration (3), implant failure (3), neurologic deficit (1), and coronal imbalance (1). Revision rates over the follow-up period were: 0 to 2 years (26/58 = 44.8%), 2 to 5 years (17/58 = 29.3%), 5 to 10 years (7/58 = 12.1%), >10 years (8/58 = 13.8%). CONCLUSION: Repeat surgical intervention following definitive spinal instrumented fusion for primary adult deformity performed at a single institution demonstrated a relatively low rate of 9.0%. The most common reasons for revision were predictable and included pseudarthrosis, proximal or distal curve progression, and infection.