Genetic Analysis of Ossification of the Posterior Longitudinal Ligament
Shunji Matsunaga, Masao Yamaguchi, Kyouji Hayashi, and Takashi Sakou

Analysis of human leukocyte antigen haplotypes was performed in families of patients with ossification of the posterior longitudinal ligament. Results indicate that genetic factors predispose toward the development of the disease.

Effects of Basic Fibroblast Growth Factor on Spontaneous Resorption of Herniated Intervertebral Discs: An Experimental Study in the Rabbit
Akihito Minamide, Hiroshi Hashizume, Munehito Yoshida, Mamoru Kawakami, Nobuhiro Hayashi, and Testuya Tamaki

The effect of basic fibroblast growth factor on newly formed vessels arising from induction of autologous intervertebral disc material into the epidural space and the resorption of this relocated disc material was studied in a rabbit model. Basic fibroblast growth factor increased neovascularization and inflammatory cells in and around the treated disc and accelerated the replacement of relocated disc material with fibrous tissue.

Corrosion on an Internal Spinal Fixator System
Uwe Vieweg, Dirk van Roost, Helmut K. Wolf, Christian A. Schyma, and Johannes Schramm

Thirteen spinal fixators were examined for corrosion using histology, microradiography, and metallography. There was extensive corrosion on the fixators with local metallosis. The composition of the metal matched specification of the manufacturer, and it is therefore thought that the construction constraints of a spinal fixator make it prone to corrosion.

Improving the Evaluation of Benign Low Back Pain
Anne Marriott, Nicholas M. Newman, Serge A. Gracovetsky, Mark P. Richards, and Steeve Asselin

Factors underlying expert clinicians' diagnostic decisions in acute benign low back pain were investigated and results compared with those obtained in an automated physical examination by machine. From this, a strategy for substantial improvement of accurate clinical diagnosis was determined.

Use of a Subjective Health Measure on Chinese Low Back Pain Patients in Hong Kong
Arran S. L. Leung, Tai-hing Lam, Anthony J. Hedley, and Lance T. Twomey

The Chinese adaptation of the Aberdeen Low Back Pain Disability Scale was tested for reliability, validity, and responsiveness on four samples of patients in Hong Kong. It was found to retain the high psychometric properties of the original English version and is therefore recommended for research and clinical use.

Are Anatomic Landmarks Reliable in Determination of Fusion Level in Posterolateral Lumbar Fusion?
Nabil A. Ebraheim, Chris Inzerillo, and Rongming Xu

The reliability of intraoperative anatomic landmarks in determining the fusion level was assessed. The results indicate that the determination of the fusion level by direct observation and palpation of the anatomic landmarks is not reliable in patients who have had or require decompression procedures. A lateral radiograph should be obtained for accurate identification of the level to be fused.

Spinal Manifestation of Metastasizing Leiomyosarcoma
Kimon Nanassis, Chariklia Alexiadou-Rudolf, and Philippos Tsitsopoulos

The case of a 46-year-old patient with a primary spinal manifestation of metastatic leiomyosarcoma and a previous histologic diagnosis of necrotizing uterine leiomyoma is reported. In retrospect, the accuracy of the previous diagnosis of a benign uterine leiomyoma was questionable.

Compression-Induced Changes in Intervertebral Disc Properties in a Rat Tail Model
James C. Iatridis, Peter L. Mente, Ian A. F. Stokes, David D. Aronsson, and Mauro Alini

A rat tail model was used to test the hypothesis that chronically applied compressive forces and immobilization cause changes in mechanical properties and composition caudal discs in a manner similar to that observed in human spinal disc degeneration. Decreases in disc thickness, axial compliance, and angular laxity and an increase in proteoglycan content of the loaded discs were noted.

A Follower Load Increases the Load-Carrying Capacity of the Lumbar Spine in Compression
Avinash G. Patwardhan, Robert M. Havey, Kevin P. Meade, Brian Lee, and Brian Dunlap

An experimental approach was used to assess the response of the whole lumbar spine to a compressive follower load, the path of which approximated the tangent to the curve of the lumbar spine. Lumbar spines supported a compressive follower load of 1200 N without hypermobility. The follower load path provides an explanation of how the whole lumbar spine can be lordotic and yet resist large compressive loads.

The Degree of Decompressive Relief and Its Relation to Clinical Outcome in Patients Undergoing Surgery for Lumbar Spinal Stenosis
Arto Herno, Tapani Saari, Olavi Suomalainen, and Olavi Airaksinen

In 92 patients with lumbar spinal stenosis, computed tomographic scans were obtained before and after surgery to determine the degree of decompressive relief. Patient satisfaction was a more important factor in surgical outcome than the postoperative radiologic findings.

An In Vivo Magnetic Resonance Imaging Study of Changes in the Volume (and Fluid Content) of the Lumbar Intervertebral Discs During a Simulated Diurnal Load Cycle
John A. Malko, William C. Hutton, and William A. Fajman

Magnetic resonance imaging was used to measure the changes in volume of the lumbar intervertebral disc in vivo during a loading cycle. Disc volume changes were related to fluid changes. The average volume increase 3 hours after removing a highly compressive load was 5.4%.

Serial Changes in Trunk Muscle Performance After Posterior Lumbar Surgery
Ryuichi Gejo, Hisao Matsui, Yoshiharu Kawaguchi, Hirokazu Ishihara, and Haruo Tsuji

Postoperative trunk muscle performance was prospectively studied in patients who underwent posterior lumbar surgery. In the long-retraction-time group, muscle damage was more severe, recovery of muscle strength was delayed, and incidence of postoperative low back pain was higher. Intraoperative care of the back muscles is advised.

Intraoperative Somatosensory Evoked Potential Findings in Acute and Chronic Spinal Canal Compromise
Karyl Norcross-Nechay, Titus Mathew, James W. Simmons, and Alexander Hadjipavlou

Somatosensory evoked potentials (SEPs) were monitored during multilevel decompression surgery and for an average of 1 year in 70 patients with chronic lumbar stenosis. Of the patients who had acute intraoperative SEP deterioration during surgery and were treated with pharmacologic intervention, 75% had no neurologic deficits. Three patients in whom SEP deterioration did not recover had new, persistent deficits. Monitoring of SEPs during lumbar surgery is advised.

The Efficacy of Active Rehabilitation in Chronic Low Back Pain: Effect on Pain Intensity, Self-Experienced Disability, and Lumbar Fatigability
Markku Kankaanpää, Simo Taimela, Olavi Airaksinen, and Osmo Hänninen

Effect on back pain intensity, functional disability, and lumbar endurance was assessed in patients with chronic low back pain treated with active rehabilitation and a passive regimen with a follow-up duration of up to 1 year. Lessened pain intensity and functional disability and increased lumbar endurance in the active rehabilitation group compared with that in the control group indicates the efficacy of active rehabilitation.

The Efficacy of Active Surgical Management of Lumbar Spinal Stenosis
Franco Postacchini

This update analyzes the indications for surgery, the methods of operative treatment, and the short- and long-term results of surgery in the various forms of lumbar stenosis alone, and of lumbar stenosis associated with degenerative spondylolisthesis or degenerative scoliosis, based on the recent literature and the author's experience.