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John E Lonstein

Publications and source records attributed to John E Lonstein.

11 recordsLinked to original sources
PubMed2006

"The disappearing evoked potentials": a special problem of positioning patients with skeletal dysplasia: case report.

STUDY DESIGN: A retrospective study of 3 patients with skeletal dysplasia, who had a loss of the evoked potentials during prone positioning before spine surgical intervention. OBJECTIVES: To bring attention to the potential hazard of neurologic compromise during the positioning of patients with skeletal dysplasia for spine surgery. Recommendations are suggested to prevent the disappearance of intraoperative evoked potentials and, therefore, possible neural injury in these patients. SUMMARY OF BACKGROUND DATA: In a very few published cases, loss or attenuation of monitored potentials has been observed at the time of initial patient positioning. Although patients with skeletal dysplasia might be considered particularly vulnerable to spinal cord injury caused by malpositioning of the head and neck, to our knowledge, no association with lost evoked potentials has previously been described. METHODS: Intraoperative transcranial electrical motor-evoked potential and/or somatosensory evoked potential baseline studies were performed after induction in the supine position. These studies were repeated as soon as practicable, after intubation and, again, after the patients were turned prone. The neurophysiologist informed the surgeon that evoked potential change in latency or amplitude met warning criteria. Alteration in the surgical plan resulted in successful spinal surgery in these cases. RESULTS: In case No. 1, repositioning of the head in flexion was sufficient to return the evoked potentials to normal. In the other two cases, attempts to reposition the patients prone failed, and the procedures were abandoned. In case No. 2, four months after the initial surgery, a halo cast for immobilization and craniocervical decompression were needed before the corrective cervical spine surgery, and in case No. 3, two steps were taken after the initial surgery: 1) trial positioning awake on the surgical table before surgery; and 2) awake postintubation prone positioning on the actual surgery day. CONCLUSIONS: Patients with skeletal dysplasia are susceptible to serious neurologic misadventure when turned to a prone position. Neurophysiologic and/or clinical monitoring of patient positioning should be undertaken, and a plan of intervention, should loss of signal or function occur, must be implemented.

Adult↗
PubMed2006

Segmental spinal dysgenesis: case report of a 50-year follow-up after surgery at age 3 years: case report.

STUDY DESIGN: Case report with ultra long-term follow-up. OBJECTIVE: To show the long-term positive benefits of an arthrodesis at age 3 years. SUMMARY OF BACKGROUND DATA: To our knowledge, there have been no previous reports of a 50-year follow-up of a posterior spine fusion for severe congenital kyphosis and segmental spinal dysgenesis. METHODS: Chart and radiographic documentation of both the preoperative, postoperative, and 50-year follow-up. RESULTS: Solid arthrodesis was achieved after a pseudarthrosis repair. Major correction was achieved and paraplegia prevented. Despite a long fusion to the sacrum, there was no junctional or sacroiliac degeneration. CONCLUSIONS: Arthrodesis at age 3 years provided an optimal ultra long-term follow-up.

Female↗
PubMed2006

Scoliosis: surgical versus nonsurgical treatment.

UNLABELLED: This article reviews the nonoperative and operative decision making process in idiopathic scoliosis in the adolescent and adult with additional comments about degenerative scoliosis. Because knowledge of the natural history of idiopathic scoliosis is essential for decision making, this will be covered first, as will the current knowledge concerning the long term outcomes of nonoperative and operative treatment. With the natural history as a background, I will discuss how the factors that are important in natural history effect decision making in the adolescent and adult. By using an evidence-based approach, hopefully a better decision-making process will result in improved outcomes. Additional treatment decisions regarding the choice of the specific nonoperative treatment methods as well as surgical decisions (fusion levels, approach, choice of implants) will not be covered. LEVEL OF EVIDENCE: Therapeutic study, level V (expert opinion). See the Guidelines for Authors for a complete description of the levels of evidence.

Age Factors↗
PubMed2006

Stepwise methodology for plain radiographic assessment of pedicle screw placement: a comparison with computed tomography.

OBJECTIVE: The objective of this study is to evaluate the effectiveness of a specific methodology for plain radiographic assessment of lumbar pedicle screw position. PURPOSE: To evaluate the effectiveness of using orthogonal plain radiographs and a systematic method of interpretation, developed by the senior author, in assessing the placement of lumbar and lumbosacral pedicle screws. STUDY DESIGN: This was an adult cadaver study of the accuracy of using plain radiographs or computed tomography to assess pedicle screw position. Plain radiographs were performed and compared with computed tomography (CT) scans. Gross anatomic dissections were performed to directly confirm screw position. Variables, including screw material, radiographic view, and screw dimensions, were assessed for their effect on the ability of physicians to determine pedicle screw position. Multiple readers were included in the study, including 1 spine Fellow, 3 experienced orthopedic spine surgeons, and 1 neuroradiologist. METHODS: Five adult cadaveric spines were instrumented with titanium pedicle screws from L1 to S1. Screws were placed outside the confines of the pedicle in all 4 quadrants or within the pedicle using a Latin-Square design. Each cadaver was imaged with orthogonal radiographs and high-resolution CT scans. The spines were then reimaged after the instrumentation was replaced with stainless steel screws placed in the identical position. Finally, each spine was dissected to assess the exact position of the screws. Images were read in a blinded fashion by 1 spine fellow, 2 staff surgeons, and a staff radiologist. The results were compared with the known screw positions at dissection. RESULTS: In total, 120 pedicle screws were placed, 44 (38%) outside the confines of the pedicle. Sensitivity, defined as the percent of the misplaced screws that were correctly identified, was similar across the 3 diagnostic tests, but markedly improved when all CT formats were considered together. Similarly, specificity, defined as the percent of screws correctly read as being placed within the pedicle, was independent of radiographic examination. Sensitivity of the radiographic technique was 70.1% and specificity was 83.0%, whereas sensitivity for CT scans was 84.7% and specificity was 89.7%. There was an observed association with anatomic level, with a consistently less accuracy in detecting screw position at L1 with plain x-ray (P=0.001). Additionally, correct position of stainless steel screws was more difficult to detect as compared with titanium (P=0.033) using either x-rays or CT. Other variables examined, such as screw length and screw diameter, did not have an effect on the ability to read the positioning. CONCLUSIONS: CT scans, often considered the "gold standard" for clinical assessment of pedicle screw placement, have limitations when validated with gross anatomical dissection. The described systematic method for evaluating pedicle screw placement using orthogonal plain radiographs attained accuracy comparable to high-resolution CT scans.

Adult↗
PubMed2004

Congenital scoliosis due to unilateral unsegmented bar: posterior spine fusion at age 12 months with 44-year follow-up.

STUDY DESIGN: Retrospective case report. PURPOSE: Long-term follow-up. METHODS: A 44-year follow-up after surgery at the age of 1 year for congenital scoliosis with original and current information. BACKGROUND INFORMATION: This long a follow-up after so young a fusion has not previously been reported. Shorter follow-ups have not revealed the problems this patient has had subsequently. RESULTS: Low back pain began 22 years after surgery (age 23 years) and cervical pain began 24 years after surgery (age 25 years). Anterior cervical discectomy and fusion plus posterior fusion of two disc levels were necessary at the age of 36 years. Continued low back pain resulting from multilevel degeneration causes major disability. CONCLUSIONS: This patient had an excellent result from his posterior spine fusion at the age of 1 year, with no loss of curve correction, no "crankshafting," and minimal loss of vital capacity. Long-term follow-up did indicate major disabilities resulting from both cervical and lumbar degenerative disc disease.

Adult↗
PubMed2003

Adolescent idiopathic scoliosis: case report with 63-year follow-up postsurgery.

STUDY DESIGN: Retrospective case report. PURPOSE: To provide true outcome analysis by a 63-year follow-up. MATERIAL AND METHODS: A 16-year-old girl had a posterior spine fusion for adolescent idiopathic scoliosis in 1939 and has been followed ever since. Both original photographs and radiographs as well as current material are available. BACKGROUND INFORMATION: A follow-up of this duration has not previously been reported. RESULTS: She had a solid T9-L3 arthrodesis and had no problems until age 50 when degenerative changes at L3-L4 required extension of the fusion to L4. When seen in 2002 at age 79, she had problems with degenerative disc disease at L4-S1 with spinal stenosis symptoms. CONCLUSIONS: The original fusion area remained solid and without symptoms for 63 years. Distal degenerative changes began 34 years after her original surgery and are still present at the 63-year follow-up. These degenerative changes at L4-L5 and L5-S1 are often thought to be secondary to the arthrodesis to L4, but because they are extremely common in persons of this age who do not have scoliosis or a fusion mass to L4, it is not possible to imply a cause and effect relationship. True outcome results cannot be ascertained at a 2-year or even 10-year follow-up.

Adolescent↗
PubMed2003

Functional outcome analysis including preoperative and postoperative SF-36 for surgically treated adult isthmic spondylolisthesis.

STUDY DESIGN: Prospective and retrospective outcome analysis following arthrodesis for adult isthmic spondylolisthesis in 31 patients. OBJECTIVE: To examine whether or not patients having such surgery have a functional improvement in their lives. SUMMARY OF BACKGROUND DATA: The literature is full of articles concerning adolescent spondylolisthesis, the union rate for adult spondylolisthesis, the ability to reduce deformities, and the outcome of surgery for degenerative spondylolisthesis, but very scant on the postoperative functional outcome of adults with isthmic spondylolisthesis. METHODS: Functional outcome was analyzed by both preoperative and postoperative SF-36 questionnaires and by four additional functional questionnaires at follow-up. RESULTS: Statistically significant improvement was seen in six of the eight SF-36 scales. Fifty-five percent of the patients scored in the normal range at follow-up compared with none before surgery. CONCLUSION: Significant functional improvement was seen following surgical arthrodesis of the painful segments in adults with isthmic spondylolisthesis (P = 0.001). This study further confirms that such surgery is appropriate for patients failing adequate nonoperative treatment.

Activities of Daily Living↗
PubMed2003

A meta-analysis of the literature on the issue of selective thoracic fusion for the King-Moe type II curve pattern in adolescent idiopathic scoliosis.

STUDY DESIGN: Meta-analysis of available literature. OBJECTIVE: To attempt to clarify the confusion existing about the "King II" idiopathic scoliosis curve pattern. SUMMARY OF BACKGROUND DATA: Since the 1983 publication by King et al, surgeons have been confused as to when to include or exclude the lumbar curve in double curve patterns. METHODS: The available literature was reviewed for relevant publications, which contained specific data analysis. Publications without adequate follow-up were excluded as were "commentary" publications unsupported by research data. RESULTS: This literature review confirms the original publication by King et al that properly identified King II curve pattern patients need selective thoracic fusion only. The fusion should end at the thoracolumbar junction. CONCLUSION: Selective thoracic fusion is the procedure of choice for properly selected King II curves.

Adolescent↗
PubMed2003

The crankshaft phenomenon after posterior spinal arthrodesis for congenital scoliosis: a review of 54 patients.

STUDY DESIGN: Retrospective chart and radiographic reviews were conducted. OBJECTIVE: To identify the incidence of and any possible risk factors for the crankshaft phenomenon after posterior spinal arthrodesis for congenital scoliosis. SUMMARY OF BACKGROUND DATA: Studies have shown the crankshaft problem to be common after posterior arthrodesis for infantile and juvenile idiopathic scoliosis, but the few reports available show it to be much less common for congenital scoliosis. METHODS: This study chose children fused before the pubertal growth spurt, all classified as Risser 0 and with open triradiate cartilages. These children were followed to the end of their growth (mean follow-up period 12 years). Several measurement parameters were used for evaluation. RESULTS: The crankshaft problem, measured as a Cobb angle increase of more than 10 degrees, was seen in 15% of the 54 patients. There was a positive correlation with earlier surgery and larger (>50 degrees) curves. No other positive correlations could be identified. CONCLUSIONS: Crankshafting was observed in 15% of the patients, more often with larger curves and earlier fusions.

Adolescent↗
PubMed2002

Long multiple struts for severe kyphosis.

The treatment of severe structural kyphosis poses a difficult problem. The use of an anterior fusion has proven to be an integral part of the surgical treatment of any kyphosis. In addition, the use of multiple struts has helped solve the treatment problem in severe kyphosis. The use of multiple struts and the role of vascularized grafts, technical details, complications, and errors and how to prevent them are discussed in the current study.

Adolescent↗