The Effect of Hydrostatic Pressure on Intervertebral Disc Metabolism
William C. Hutton, William A. Elmer, Scott D. Boden, Steve Hyon, Yasumitsu Toribatake, Katsuro Tomita, and Gregory A. Hair

The hypothesis that hydrostatic pressure directly affects the synthesis of collagen and proteoglycan by the intervertebral disc cells was tested using pressure vessels to apply hydrostatic pressure to disc cells cultured in alginate.

The Role of Mast Cells in Disc Herniation Inflammation
Aklilu Habtemariam, Johanna Virri, Mats Grönblad, Seppo Seitsalo, and Erkki Karaharju

To determine the possible role of mast cells in disc herniation inflammation, a histologic and immunohistochemical study was performed on 50 disc herniations from patients undergoing disc surgery. Mast cells were observed in a minority of disc tissue samples (9/50 [18%] and 10/50 [20%] by toluidine blue and immunohistochemical staining, respectively). This result may suggest a possible role of mast cells in disc tissue inflammation, but only in a subset of disc herniations.

The Use of an Injectable, Biodegradable Calcium Phosphate Bone Substitute for the Prophylactic Augmentation of Osteoporotic Vertebrae and the Management of Vertebral Compression Fractures
Bo Bai, Laith M. Jazrawi, Frederick J. Kummer, and Jeffrey M. Spivak

A biomechanical study was performed to compare two materials for augmentation of osteoporotic vertebral bodies and vertebral bodies that have sustained a compression fracture. The results demonstrated that the injection of a biodegradable Ca-P bone substitute to strengthen osteoporotic vertebral bodies and improve vertebral compression fractures might provide an alternative to the use of PMMA.

Effect of Decompression Enlargement Laminoplasty for Posterior Shifting of the Spinal Cord
Tomonori Sodeyama, Sumio Goto, Makondo Mochizuki, Junichi Takahashi, and Hideshige Moriya

The posterior shift of the spinal cord was measured by computed tomographic myelography. A mean spinal cord shift of more than 3 mm was closely related to good clinical outcomes after enlargement laminoplasty. Extension of decompression one level above or one level below is likely associated with greater spinal cord shift only at the level of decompression of the upper or lower cervical spine.

Long-Term Clinical and Magnetic Resonance Imaging Follow-Up Assessment of Patients With Lumbar Spinal Stenosis After Laminectomy
Arto Herno, Kaarina Partanen, Tiina Talaslahti, Erkki Kaukanen, Veli Turunen, Olavi Suomalainen, and Olavi Airaksinen

The correlation between postoperative findings on magnetic resonance images (MRIs) and clinical observations of 56 patients 10 years after laminectomy for lumbar spinal stenosis was examined. The patient's perception of improvement had a much stronger correlation with the surgical outcome than stenotic or degenerative findings on postoperative MRIs. Degenerative findings on MRIs had a greater effect on the patient's walking capacity than stenotic findings.

Luque Trolley and Convex Epiphysiodesis in the Management of Infantile and Juvenile Idiopathic Scoliosis
Roland K. Pratt, John K. Webb, R. Geoffrey Burwell, and Susannah L. Cummings

The results from the follow-up assessment performed 5 years after treatment with Luque trolley with and without a convex epiphysiodesis for patients with progressive infantile and juvenile idiopathic scoliosis were evaluated. Combined Luque trolley and convex epiphysiodesis provides advantages to the prolonged use of plaster jackets or braces in the management of infantile idiopathic scoliosis.

Thoracic Discography in Healthy Individuals: A Controlled Prospective Study of Magnetic Resonance Imaging and Discography in Asymptomatic and Symptomatic Individuals
Kirkham B. Wood, Kurt P. Schellhas, Timothy A. Garvey, and Dorothee Aeppli

A prospective case-control investigation was performed to determine the responses of asymptomatic individuals to thoracic discography. On discography, discs with prominent Schmorl's nodes may be intensely painful, even in lifelong asymptomatic individuals, but the pain is unfamiliar and nonconcordant. Thoracic discography may demonstrate disc pathology not seen on magnetic resonance imaging.

Short-Term Physical Risk Factors for New Episodes of Low Back Pain: Prospective Evidence From the South Manchester Back Pain Study
Peter R. Croft, Ann C. Papageorgiou, Elaine Thomas, Gary J. Macfarlane, and Alan J. Silman

A population-based cohort of 2715 adults, 18-75 years of age and with no current low back pain, was observed for 1 year. In general, physical activity outside the workplace did not affect the incidence of low back pain, whereas poor physical health in both genders and high weight in women did increase the risk of new low back pain episodes in the short term.

The Influence of Previous Low Back Trouble, General Health, and Working Conditions on Future Sick-Listing Because of Low Back Trouble: A 15-Year Follow-Up Study of Risk Indicators for Self-Reported Sick-Listing Caused by Low Back Trouble
Cecilia Florvall Müller, Tina Monrad, Fin Biering-Sřrensen, Erik Darre, Allan Deis, and Peter Kryger

A 15-year follow-up study was performed to identify risk factors for future self-reported sick-listing resulting from low back trouble (LBT). The logistic regression analyses showed 22 of 37 variables to be significant indicators. When analyzing the significant variables simultaneously, the authors found that the risk for sick-listing could be determined by the previous sick-listing pattern in general, and, because of low back trouble, by the intensity of the previous LBT (based on sciatic pain and the use of analgesics), and by the patient's age and occupation.

Meta-Analysis of Normative Cervical Motion
Jasper Chen, Alan B. Solinger, Jacques F. Poncet, and Charles A. Lantz

A meta-analysis was done of the literature on normative cervical range of motion (ROM) to highlight strengths and weaknesses of measurement technologies. Variations within each technology were found to be larger than those between technologies, indicating that procedures are as important as accuracy and precision of the technology. "Best-estimates" of normative ROM and recommendations for further research are provided.

Randomized Trial Comparing Interferential Therapy With Motorized Lumbar Traction and Massage in the Management of Low Back Pain in a Primary Care Setting
Roland Werners, Paul B. Pynsent, and Christopher J. K. Bulstrode

A total of 152 patients with low back pain were recruited for this randomized trial. No difference between the two treatment groups was found over a 3-month period, with symptoms improving in both groups. The therapeutic value of these treatments is questioned.

The Effect of a Mensendieck Exercise Program as Secondary Prophylaxis for Recurrent Low Back Pain: A Randomized, Controlled Trial With 12-Month Follow-Up
Margreth G. Soukup, Bredo Glomsröd, Jan H. Lönn, Kari Bö, and Stig Larsen

A Mensendieck exercise intervention with a focus on body awareness, ergonomic training, and exercises mirroring daily life activities had a significant effect on recurrences of low back pain episodes in a randomized, controlled study. In addition, there were improvements in pain and function scores, but no significant difference between the Mensendieck and control groups.

The Value of Somatosensory- and Motor-Evoked Potentials in Predicting and Monitoring the Effect of Therapy in Spondylotic Cervical Myelopathy: Prospective Randomized Study
Josef Bednarík, Zdenek Kadanka, Stanislav Vohánka, Lubor Stejskal, Otto Vlach, and Roman Schröder

A prospective randomized electrophysiologic and clinical study with a 2-year follow-up period was performed in patients with varying degrees of spondylotic cervical cord involvement. Changes in somatosensory- and motor-evoked potentials correlated fairly with clinical changes and showed no difference in the outcome for patients with mild spondylotic cervical myelopathy treated surgically or conservatively.

Anatomic Evaluation of Two Different Techniques for the Percutaneous Insertion of Pedicle Screws in the Lumbar Spine
Lothar Wiesner, Ralph Kothe, and Wolfgang Rüther

In this in vitro study, the accuracy of percutaneous pedicle screw insertion was analyzed in the lumbar spine. Using a human cadaver model, two different techniques were analyzed regarding the degree and direction of pedicle violations. Of 360 pedicle screws, only 37 were misplaced, resulting in an overall misplacement rate of 10%. There was no significant difference between the Magerl technique (misplacement rate, 13%) and a new modified technique (misplacement rate, 8%).

Anterior Cervical Reconstruction Using Titanium Cages With Anterior Plating
Mohammad E. Majd, Mukta Vadhva, and Richard T. Holt

In this preliminary outcome assessment study, the efficacy and safety of titanium cage implants with anterior cervical plating were evaluated in cervical spine reconstruction. The titanium mesh cages provided immediate strong anterior column support and avoided morbidity at the bone graft site, with no hardware complications, in 30 of 34 patients.

Extraspinal Bone and Soft-Tissue Tumors as a Cause of Sciatica: Clinical Diagnosis and Recommendations: Analysis of 32 Cases
Jacob Bickels, Neil Kahanovitz, Cynthia K. Rubert, Robert M. Henshaw, David P. Moss, Isaac Meller, and Martin M. Malawer

The authors describe 32 patients with sciatica who eventually were found to have a bone or soft-tissue tumor along the course of the sciatic nerve. To diagnose these rare conditions early and accurately, special attention should be given to the pain pattern, physical examination, and use of appropriate imaging studies.

The Old and the New Camptocormia
Kazimierz Karbowski

A psychogenic forced posture with a forward-bent trunk was termed "camptocormia"by Souques in 1915. This syndrome must be differentiated from recently described "camptocormic" postural anomalies resulting from somatics diseases of the paravertebral muscles.