The use of pedicle screw fixation to improve correction in the lumbar spine of patients with idiopathic scoliosis. Is it warranted?

Study Design: A retrospective assessment of coronal, sagittal, and axial correction using convex lumbar pedicle screw constructs compared with hook constructs in patients with idiopathic scoliosis.

Objective: To determine if pedicle screw constructs can improve coronal, sagittal, and axial correction without increased complications and therefore warrant their use in the lumbar spine.

Summary Of Background Data: Although hooks have been the traditional fixation choice for posterior scoliosis correction of the lumbar spine, pedicle screws may offer advantages for improved correction of lumbar spinal deformity.

Validity and reliability of spinal cord monitoring in neuromuscular spinal deformity surgery.

Somatosensory evoked potentials (SSEPs) have become a standard of care in surgery for spinal deformity. Recent reports in the literature have suggested SSEP monitoring is not efficacious in surgeries for patients with neuromuscular disease. Electrophysiologic data were retrospectively analyzed from 74 patients with various neuromuscular disorders undergoing spinal-deformity surgery from 1989 through February 1995 at this medical center.

Torulopsis glabrata spinal osteomyelitis involving two contiguous vertebrae. A case report.

Study Design: A case report and literature review of the five previous case reports.

Objectives: To outline the features of Torulopsis glabrata spinal osteomyelitis, including its risk factors, diagnosis, and recommended treatments.

Summary Of Background Data: Fungal infections in general and Torulopsis glabrata in particular are becoming increasingly prevalent.

Triggered electromyographic threshold for accuracy of pedicle screw placement. An animal model and clinical correlation.

Study Design: This study consisted of a laboratory investigation of triggered electromyographic stimulation of pedicle screws placed in a pig spine, with a correlative prospective clinical series of lumbosacral pedicle screws stimulated in a similar fashion.

Objectives: To determine the threshold of stimulus intensity necessary to confirm accuracy of lumbar pedicle screw placement via a triggered electromyographic peripheral response.

Summary Of Background Data: Documentation of lumbar pedicle screw placement is imperative to perform proper spinal instrumentation and to avoid perioperative complications.

Anterior fresh frozen structural allografts in the thoracic and lumbar spine. Do they work if combined with posterior fusion and instrumentation in adult patients with kyphosis or anterior column defects?

Study Design: This was a prospective study of 24 adult patients with kyphosis or anterior column spinal defects treated with anterior fresh frozen allograft for anterior column defects and posterior instrumentation and autogenous grafting.

Objectives: The objectives of the study were to assess the effectiveness of the anterior allograft in maintaining sagittal correction and to assess anterior incorporation.

Summary Of Background Data: Twenty-four patients were followed for a minimum of 2 years (range, 2 + 0-5 + 4 years).

Prospective analysis of nutritional status normalization after spinal reconstructive surgery.

Study Design: A prospective analysis of nutritional status after surgery in 57 spinal reconstructive surgery patients.

Objectives: To determine the length of time required for patients to return to their preoperative nutritional baseline and to investigate risk factors for patients with prolonged normalization.

Summary Of Background Data: The preoperative nutritional status of spinal reconstructive surgery patients appears to be an important parameter of surgical morbidity, complication rates (especially wound healing), patient acceptance, and overall surgical success.

An analysis of sagittal spinal alignment in 100 asymptomatic middle and older aged volunteers.

Study Design: A radiographic evaluation of 100 adult volunteers over age 40 and without a history of significant spinal abnormality was done to determine indices of sagittal spinal alignment.

Objectives: To determine the sagittal contours of the spine in a population of adults older than previously reported in the literature and to correlate age and overall sagittal balance to other measures of segmental spinal alignment.

Summary Of Background Data: Previous studies of sagittal alignment have focused on adolescent and young adult populations before the onset of degenerative changes that may affect sagittal alignment.

Analysis of pulmonary function and chest cage dimension changes after thoracoplasty in idiopathic scoliosis.

Study Design: A prospective study of 19 adolescents and seven adults with idiopathic scoliosis undergoing posterior spinal fusion with segmental spinal instrumentation and a concomitant thoracoplasty had pulmonary function evaluation before surgery and at selected time points up to a minimum 2 years after surgery.

Objectives: The objectives were to determine the effects thoracoplasty had on pulmonary function and chest cage dimension changes at a minimum 2-year follow-up in idiopathic scoliosis patients.

Summary Of Background Data: The cosmetic benefits of thoracoplasty on the rib hump deformity are well accepted.

A 13-year-old boy with rapidly progressive spinal deformity.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Posterior spinal fusion supplemented with only allograft bone in paralytic scoliosis. Does it work?

Study Design: The authors prospectively evaluated 40 patients with paralytic scoliosis treated from 1985 to 1990 with bilateral posterior segmental instrumentation, facet fusions, local bone graft, and allograft (mostly fresh frozen) bone supplementation only.

Objectives: The authors report the fusion results for these patients, and any complications referable to the use of bank bone.

Summary Of Background Data: Acceptable correction was obtained and maintained in the coronal and sagittal planes for all but two patients (the third patient with a pseudarthrosis had not lost correction).

Astrocyte response and transforming growth factor-beta localization in acute spinal cord injury.

Study Design: An experimental histologic and immunohistological investigation of acute spinal cord injury was performed in a rat model.

Objective: This study determined (1) the immediate cellular and molecular responses within the spinal cord that result from a clinically relevant compression injury, (2) the acute astrocytic response to injury using the astrocyte specific GFAP antibody, and (3) the temporal pattern of cellular and extracellular localization of transforming growth factor-beta 1 (TGF-beta 1) within the spinal cord injury zone immediately after injury.

Summary Of Background Data: Ultimate neurologic outcome from spinal cord injury results from both the primary mechanical trauma and a subsequent cascade of cellular and molecular events that are termed the secondary injury.

Evoked potential monitoring of the upper extremities during thoracic and lumbar spinal deformity surgery: a prospective study.

We prospectively investigated the usefulness of somatosensory evoked potential (SEP) monitoring to detect clinically significant peripheral nerve or brachial plexus compression in the upper extremities during spinal deformity surgery. All patients had bilateral median and ulnar nerve SEPs evaluated as a baseline, both intermittently throughout the surgical procedure and at termination of surgery. This information was correlated with pre- and postoperative upper extremity neurologic examinations.

Preoperative spinal canal investigation in adolescent idiopathic scoliosis curves > or = 70 degrees.

Study Design: This is a prospective evaluation of a consecutive series of patients with adolescent idiopathic scoliosis (AIS) with curves > or = 70 degrees.

Objective: The authors investigated the possibility that large curve size may constitute an atypical presentation of idiopathic scoliosis suggestive of underlying neurologic pathology, which would warrant preoperative investigation.

Summary Of Background Data: The potential for intraspinal pathology to cause scoliosis is well accepted.

Recognition and treatment of the proximal thoracic curve in adolescent idiopathic scoliosis treated with Cotrel-Dubousset instrumentation.

Study Design: A retrospective radiographic and clinical review of a consecutive series of patients with adolescent idiopathic scoliosis (AIS) instrumented/fused with Cotrel-Dubousset instrumentation (CDI) was undertaken.

Objective: The authors determined criteria when the upper thoracic curve should be instrumented/fused in AIS treated with CDI and assessed the results of surgical treatment.

Summary Of Background Data: Failure to recognize and include the upper left thoracic curve in the instrumentation/fusion of a lower right thoracic idiopathic scoliosis may produce shoulder imbalance and coronal decompensation.

Intracanalicular osteochondroma producing spinal cord compression in hereditary multiple exostoses.

Spinal cord compression is an unusual but potentially catastrophic manifestation of hereditary multiple exostoses (HMEs). Isolated, osteochondromas are usually of little significance. However, if they are located near neurologic structures, they may cause irritation due to mechanical compression.

Diagnosis of perioperative myocardial infarction with measurement of cardiac troponin I.

Background: Perioperative myocardial infarction is the most common cause of morbidity and mortality in patients who have had noncardiac surgery, but its diagnosis can be difficult. The present study was designed to determine whether the measurement of serum levels of cardiac troponin I, a highly sensitive and specific marker for cardiac injury, would help establish the diagnosis of myocardial infarction.

Methods: We obtained preoperative measurements of MB creatine kinase, total creatine kinase, and cardiac troponin I, in addition to base-line electrocardiograms and two-dimensional echocardiograms, in 96 patients undergoing vascular surgery and 12 undergoing spinal surgery.

Increase in creatine kinase MB isoenzyme levels after spinal surgery.

Serial assays of creatine kinase (CK) and particularly its isoenzyme CK-MB are the tests of choice for the laboratory confirmation of myocardial tissue damage. However, elevations attributable to skeletal muscle injury also have been reported, and we noted elevated levels of total CK, CK-MB, and percent MB postoperatively following spinal surgery in some of our patients. To define prospectively the frequency of elevations and their clinical correlates, we studied 20 consecutive spinal surgical procedures in 17 adults.

The role of fusion and instrumentation in the treatment of degenerative spondylolisthesis with spinal stenosis.

Between February 1985 and March 1990 44 patients with degenerative spondylolisthesis underwent primary surgery for spinal stenosis (in all cases the decompression preserved the facets bilaterally without discectomy) and were studied prospectively. Forty-three patients have been followed for > or = 2 years and are the basis of this study. There were three treatment groups: group I, no fusion (nine patients); group II, transverse process fusion with autogenous iliac bone graft without instrumentation (11 initial patients, with one lost to follow-up for a total of 10); and group III, transverse process fusion with autogenous iliac crest bone graft and instrumentation (24 patients, 18 with one-level pedicle fixation and six with two-level fixation).

Ability of Cotrel-Dubousset instrumentation to preserve distal lumbar motion segments in adolescent idiopathic scoliosis.

Between 1985 and 1990, 44 patients with adolescent idiopathic scoliosis were treated with Cotrel-Dubousset instrumentation when Harrington instrumentation would have extended into the distal lumbar spine (L3, L4, or L5) for these curve patterns. Twenty-four of these 44 (group I) patients had one distal fusion level preserved using Cotrel-Dubousset instrumentation, whereas the other 20 patients (group II) were instrumented/fused with Cotrel-Dubousset instrumentation to the expected Harrington instrumentation level in the lower lumbar spine. All patients have a minimum 2-year follow-up, and the average follow-up is 39 months (range 24-74).

Use of sciatic neurogenic motor evoked potentials versus spinal potentials to predict early-onset neurologic deficits when intervention is still possible during overdistraction.

Spinal evoked potentials, sciatic neurogenic motor evoked potentials, and somatosensory evoked potentials were recorded before and after overdistraction of the spinal cord, and compared with the clinical status of 14 pigs. The sciatic neurogenic motor evoked potential consisted of two components: fast and slow. The fast component was more sensitive and associated to a greater degree with motor function in wake-up tests than the slow component somatosensory evoked potential and spinal evoked potential.

Innervation pattern of dorsal roots and their effects on the specificity of dermatomal somatosensory evoked potentials.

Dermatomal somatosensory evoked potentials are used to monitor individual nerve root function during degenerative spinal surgery. However, a less than 100% agreement between level(s) of dermatomal somatosensory evoked potentials abnormality and nerve root involvement has been reported. The purpose of this article was to determine the possible cause of this discrepancy.

Results of in situ fusion for isthmic spondylolisthesis.

Between 1976 and 1990, we treated 56 isthmic spondylolisthesis patients with an average age of 15 + 4 (range, 4 + 9 to 27 +/- 2) with in situ bilateral transverse process fusions utilizing autogenous iliac bone graft. None of the patients had a decompression or instrumentation placed. Radiographic fusion was determined from standing spot lateral radiographs and either Ferguson AP or standing AP views of the lumbosacral junction.