Adult spine deformity.

Adult spinal deformity may occur as the result of a number of conditions and patients may present with a heterogeneous group of symptoms. Multiple etiologies may cause spinal deformity; however, symptoms are associated with progressive and asymmetric degeneration of the spinal elements potentially leading to neural element compression. Symptoms and clinical presentation vary and may be related to progressive deformity, axial back pain, and/or neurologic symptoms. Spinal deformity is becoming more common as adults 55-64 years of age are the fastest growing proportion of the U.S. population. As the percentage of elderly in the United States accelerates, more patients are expected to present with painful spinal conditions, potentially requiring spinal surgery. The decision between operative and nonoperative treatment for adult spinal deformity is based on the severity and type of the patient's symptoms as well as the magnitude and risk of potential interventions.

Convex hemiepiphysiodesis: the limits of vertebral stapling.

STUDY DESIGN: We performed a retrospective chart review of patients with nonadolescent idiopathic scoliosis who underwent open vertebral stapling for treatment of spinal deformity. OBJECTIVE: The objective of this study was to determine the efficacy of vertebral stapling in patients with scoliosis. Measurements included initial deformity correction and maintenance of correction. SUMMARY OF BACKGROUND DATA: Growth modulation has become a topic of interest recently in the spinal deformity literature. It refers to the tethering of growth on one side of the spine to allow for compensatory growth on the contralateral side, and, in theory, correction of scoliosis. Recent studies on endoscopic vertebral stapling have shown promising early results in adolescents with idiopathic scoliosis. Little is known about its applicability in patients with more "malignant" types of scoliosis. METHODS: The medical records and radiographs of 11 children who underwent open vertebral stapling between June 2003 and August 2004 were reviewed. Patients with adolescent idiopathic scoliosis (AIS) were excluded. RESULTS.: Diagnoses included myelodysplasia, congenital scoliosis, juvenile, and infantile idiopathic scoliosis, Marfan syndrome, paralytic scoliosis, and neuromuscular scoliosis. The average age at surgery was 6 + 11 year. All patients were skeletally immature. Preoperative curves averaged 68° (22°-105°). Of the 11, six thoracic curves and five thoracolumbar curves were stapled. Four patients had minor curves, which were not stapled. Initial postoperative radiographs averaged 45° (24°-88°). Average follow-up was 22 month for our series (16-28 month). At final follow-up, scoliosis averaged 69° (36°-107°). Five of the 11 patients have subsequently undergone secondary surgical procedures for progression of scoliosis, including growing rod insertion in three, combined anterior/posterior spinal fusion in another, and bilateral vertical expandable prosthetic titanium rib insertion in a patient with myelodysplasia. Three of the remaining six patients are scheduled for secondary surgery. CONCLUSION: More than half of the patients in our series have undergone or are scheduled to undergo further spinal surgery, at an average of 2 year after anterior vertebral stapling. It is unclear if progression may be related to the young age at surgery, the relatively severe average preoperative curve magnitude, the nature of the underlying scoliosis, or a combination of these.

Cervical disc arthroplasty.

This technology overview addressed four questions that compared the difference in outcomes between patients undergoing cervical disc arthroplasty with patients undergoing anterior cervical diskectomy fusion. Most studies did not either report or conduct the appropriate statistical analyses to examine predictive characteristics in patients with successful clinical outcomes. Most studies were inconclusive or unreliable regarding clinical outcomes and revision and/or complication rates in patients who present with neck and/or arm pain. No significant difference in the length of hospital stay was reported; however, two studies included in the overview reported that patients treated with cervical disc arthroplasty returned to work in significantly fewer days (range, 14 to 16 days) than did patients treated with anterior cervical diskectomy fusion.

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.

Posterior vertebral column resection for severe pediatric deformity: minimum two-year follow-up of thirty-five consecutive patients.

STUDY DESIGN: Retrospective review of a prospectively accrued patient cohort. OBJECTIVE: The ability to treat severe pediatric spinal deformity through an all-posterior vertebral column resection (VCR) has obviated the need for a circumferential approach in both primary and revision settings. We examined indications, correction rates, and complications of this challenging procedure in the pediatric population. SUMMARY OF BACKGROUND DATA: Traditionally, severe pediatric spinal deformities were treated through a combined anterior/posterior spinal fusion. METHODS: Between 2000 and 2005, 35 consecutive patients underwent a posterior-only VCR by 1 of 2 surgeons at a single institution. Patients were divided into 5 diagnostic categories: (1) severe scoliosis (S) (n = 2; mean, 115 degrees; range, 79-150 degrees; average flexibility, 12%); (2) global kyphosis (GK) (n = 3; mean, 101 degrees; range, 91-113 degrees; average flexibility, 16%); (3) angular kyphosis (AK) (n = 10; mean, 86 degrees; range, 45-135 degrees, average flexibility, 23%); (4) kyphoscoliosis (KS) (n = 8; mean kyphosis, 103 degrees/scoliosis 87 degrees; mean combined, 190 degrees; range, 144-237 degrees); (5) congenital scoliosis (CS) (n = 12; mean, 43 degrees; range, 23-69 degrees; average flexibility, 20%). There were 20 primary/15 revision surgeries. There were 20 one-level, 11 two-level, and 4 three-level resections. RESULTS: The major curve correction averaged: Group S = 61 degrees/51%, Group GK = 56 degrees/55%, Group AK = 51 degrees/58%, Group KS = 98 degrees/54%, and Group CS = 24 degrees/60%. The average OR time was 460 minutes (range, 210-822), with an average EBL of 691 mL (range, 125-2200). There were no spinal cord-related complications; however, 2 patients (8.5%) lost intraoperative neuromonitoring data during correction with data returning to baseline following prompt surgical intervention. Two patients had implant revisions, 1 for a delayed deep infection at 2 years and the other for implant prominence at 3-year follow-up. CONCLUSION: A posterior-based VCR is a safe but challenging technique to treat severe primary or revision pediatric spinal deformities. Intraoperative SCM (especially motor-evoked potentials) is mandatory to prevent spinal cord-related neurologic complications. Dramatic radiographic and clinical correction of these deformities can be obtained via a posterior-only approach.

Risk factors and outcomes for catastrophic failures at the top of long pedicle screw constructs: a matched cohort analysis performed at a single center.

STUDY DESIGN: Retrospective review with matched-cohort analysis performed at a single institution. OBJECTIVE: To determine risk factors and outcomes for acute fractures at the proximal aspect of long pedicle screw constructs. SUMMARY OF BACKGROUND DATA: Acute fractures at the top of long segmental pedicle screw constructs (FPSC) can be catastrophic. Substantial surgical increase in lordosis may precipitate this problem. In relation to a matched cohort, we postulated that age, body mass index (BMI), and significant correction of lumbar lordosis would increase risk of FPSC and patients with FPSC would have lesser improvements in outcomes. METHODS: Thirteen patients who sustained FPSC between 2000 and 2007 were evaluated. During this time, 264 patients aged 40 or older had a spinal fusion from the thoracic spine to the sacrum using an all-pedicle screw construct. A cohort of 31 of these patients without FPSC but with all pedicle screw constructs was matched for diagnosis of positive sagittal imbalance, gender, preoperative C7 sagittal plumb, and number of levels fused. RESULTS: There was a significant difference in age (P = 0.02) and BMI (P = 0.006) between the matched groups. There was no significant difference in preoperative/postoperative C7 plumb or change in lumbar lordosis between groups. Acute neurological deficit developed in 2 patients; both patients improved substantially after revision surgery. Nine patients underwent proximal extension of the fusion. For 7 of the 13 FPSC patients with bone mineral density data (BMD) available, average T score was-1.73; -0.58 for the matched group (10/31 with bone mineral density data) (P = 0.02). CONCLUSION: Factors that increased the risk of FPSC included obesity and older age. Osteopenia increased the risk as evidenced by BMD (based on 17 patients) and the older age of these patients. There was no statistical difference in clinical improvement between groups based on ODI, but the FPSC group did demonstrate a smaller improvement in ODI score than the matched cohort.