Correlation between leg pain at rest and spinal nerve edema in symptomatic lumbar foraminal stenosis

BACKGROUND

Previous studies reported that spinal nerve edema on magnetic resonance myelography (MRM) and leg pain at rest were specifically observed in symptomatic lumbar foraminal stenosis patients. However, the correlation between leg pain at rest and spinal nerve edema in symptomatic foraminal stenosis has not been reported.

HYPOTHESIS

The purpose of this prospective study is to reveal a correlation between leg pain at rest and spinal nerve edema focusing on the pathophysiology of symptomatic foraminal stenosis.

PATIENTS AND METHODS

Clinical findings and MRM findings were surveyed among 30 patients with symptomatic foraminal stenosis diagnosed by MR imaging (MRI) and selective nerve root block. Comparisons of patient characteristics and clinical findings between the prevalence and absence groups of spinal nerve edema on MRM were analyzed. A correlation between the visual analogue scale (VAS) for leg pain at rest and the spinal edema ratio calculated as maximum intensity value of the affected spinal nerve/maximum intensity value of the asymptomatic side from region of interest (ROI) made on MRM was evaluated.

RESULTS

Twenty symptomatic foraminal stenosis cases (67%) showed the affected spinal nerve edema on MRM. The prevalence and VAS of leg pain at rest were significantly higher in the presence of spinal nerve edema group (95% and 67.0±36.4, respectively). The correlation coefficient between the VAS for leg pain at rest (53.0±33.6) and the spinal nerve edema ratio (1.3±0.3) was 0.647 (p<0.01).

DISCUSSION

Our study revealed the substantial correlation found between the spinal nerve edema ratio on MRM and the VAS for leg pain at rest in symptomatic foraminal stenosis. The correlation between spinal nerve edema and leg pain at rest has potential to clarify the pathology of symptomatic foraminal stenosis.

LEVEL OF EVIDENCE

IV.

Upper Thoracic Compensation against Global Malalignment and Spinopelvic Mismatch in Adult Spinal Deformity Patients Analyzed Using the EOS Imaging System

Introduction

Patients with adult spinal deformity (ASD) develop compensatory mechanisms. The Cobb angle between T4 and T12 has been used as a standard to define thoracic kyphosis (TK) because radiological evaluation is difficult in upper thoracic region. The upper thoracic compensatory mechanism has not been sufficiently explored, and focal thoracic compensation remains poorly understood. This study aimed to determine upper sagittal thoracic compensation and features of thoracic compensation in ASD patients.

Methods

The records of 218 consecutive patients who underwent full-standing EOS imaging were retrospectively examined. Spinopelvic parameters-including the T1-T12, T4-T12, T1-T4, T5-T8, and T9-T12 angles-were measured using a dedicated and validated software. The relationship between the thoracic and spinopelvic parameters was statistically evaluated. Thoracic compensation was compared among four typical types of spinal deformity.

Results

A total of 127 ASD patients met the inclusion criteria. TK(1-12) was negatively correlated with the sagittal vertical axis (SVA) (r=-0.35), T1 pelvic angle (TPA) (r=-0.29), and pelvic incidence minus lumbar lordosis (PI-LL) (r=-0.60). TK(1-4) showed a stronger correlation with the SVA and TPA than TK(5-8) or TK(9-12) (r=-0.39, -0.38, respectively). TK(1-4), TK(5-8), and TK(9-12) had a similar negative correlation with PI-LL; however, TK(5-8) had the strongest correlation (r=-0.38). Both age and TK(9-12) were significantly associated with decreased TK(1-4), and vertebral fracture was significantly associated with increased TK(9-12). Both patients with high SVA and those in the hyperthoracic kyphosis group had lower TK(1-4) angles.

Conclusions

In ASD patients, upper thoracic spine compensation plays an important role in countering global malalignment. The middle part of the thoracic spine has a strong correlation with LL. This study findings can help clinicians better manage ASD patients.

Surgical Intervention for Osteoporotic Vertebral Burst Fractures in Middle-low Lumbar Spine with Special Reference to Postoperative Complications Affecting Surgical Outcomes

The purpose of this study was to investigate the clinical and radiological features of osteoporotic burst fractures affecting levels below the second lumbar (middle-low lumbar) vertebrae, and to clarify the appropriate surgical procedure to avoid postoperative complications. Thirty-eight consecutive patients (nine male, 29 female; mean age: 74.8 years; range: 60-86 years) with burst fractures affecting the middle-low lumbar vertebrae who underwent posterior-instrumented fusion were included. Using the Magerl classification system, these fractures were classified into three types: 16 patients with superior incomplete burst fracture (superior-type), 11 patients with inferior incomplete burst fracture (inferior-type) and 11 patients with complete burst fracture (complete-type). The clinical features were investigated for each type, and postoperative complications such as postoperative vertebral collapse (PVC) and instrumentation failure were assessed after a mean follow-up period of 3.1 years (range: 1-8.1 years). All patients suffered from severe leg pain by radiculopathy, except one with superior-type fracture who exhibited cauda equina syndrome. Nineteen of 27 patients with superior- or inferior-type fracture were found to have spondylolisthesis due to segmental instability. Although postoperative neurological status improved significantly, lumbar lordosis and segmental lordosis at the fused level deteriorated from the postoperative period to the final follow-up due to postoperative complications caused mainly by PVC (29%) and instrument failure (37%). Posterior-instrumented fusion led to a good clinical outcome; however, a higher incidence of postoperative complications due to bone fragility was inevitable. Therefore, short-segment instrument and fusion with some augumentation techniqus, together with strong osteoporotic medications may be required to avoid such complications.

Minodronate treatment improves low bone mass and reduces progressive thoracic scoliosis in a mouse model of adolescent idiopathic scoliosis

Recent studies have shown an association between osteopenia and adolescent idiopathic scoliosis (AIS) and implied that osteopenia plays a causative role in AIS development. This study aimed to determine if minodronate (MIN) treatment could prevent curve progression by increasing bone mass in a thoracic restraint (TR) mouse model, which develops causes the development of thoracic scoliosis similar to human AIS. A total of 100 young female C57BL6J mice were divided into four groups: (1) control with vehicle (CON/VEH; n = 20), (2) control with MIN (CON/MIN; n = 20), (3) TR with vehicle (TR/VEH; n = 30), or (4) TR with MIN (TR/MIN; n = 30). MIN (0.01 mg/kg/week) and vehicle were administered intraperitoneally to their respective groups. TR was performed at age 4 weeks, and the mice were sacrificed at age 9 weeks. Body weights, spine radiographs, femoral bone mineral density (BMD), serum bone marker levels, and histomorphometry of the cancellous bone of the thoracic vertebrae were analyzed. TR significantly reduced weight gain in the TR/VEH group relative to the CON/VEH group. TR also induced osteoporosis with accelerated bone resorption, as indicated by decreases in femoral BMDs and thoracic cancellous bone volume and increases in serum bone resorption marker levels and histomorphometric resorption parameters in the TR/VEH group. MIN partially improved body weight gain and improved poor bone structure relative to the TR/VEH group by suppressing high bone resorption in the TR/MIN mice. MIN significantly reduced the curve magnitudes, as indicated by a 43% lower curve magnitude in the TR/MIN mice than in the TR/VEH mice (17.9 ± 8.9° vs. 31.5 ± 13.1°; p< 0.001). The administration of MIN increased bone mass and reduced the severity of scoliosis in the TR mice. MIN was suggested as a possible inhibitor of scoliosis development.

Evaluation of functional and structural leg length discrepancy in patients with adolescent idiopathic scoliosis using the EOS imaging system: a prospective comparative study

Background

To our knowledge, no studies have reported the exact structural leg length discrepancies (LLDs) in patients with adolescent idiopathic scoliosis (AIS). Therefore, this study aimed to evaluate the differences between functional and structural LLDs and to examine the correlations between LLDs and spinopelvic parameters in patients with AIS using an EOS imaging system, which permits the three-dimensional reconstruction of spinal and lower-limb bony structures.

Methods

Eighty-two consecutive patients with AIS underwent whole-body EOS radiography in a standing position between August 2014 and March 2016. Functional LLD, lumbar Cobb angle, thoracic curve Cobb angle, coronal balance, and pelvic obliquity were measured using two-dimensional EOS radiography. Structural LLDs were measured using three-dimensional EOS-reconstructed images. The comparison between LLDs was assessed using paired t test. Pearson's correlation coefficient (r) was used to determine potential correlations between the LLDs and spinopelvic alignment parameters.

Results

Functional LLDs were significantly larger than structural LLDs (5.6 ± 5.0 vs. 0.2 ± 3.6 mm, respectively; p < 0.001). Both functional and structural LLDs were significantly correlated with pelvic obliquity (r = 0.69 and r = 0.51, respectively; p < 0.001 for both). Functional LLD, but not structural LLD, was correlated with lumbar Cobb angle (r = 0.44, p < 0.001; r = 0.17, p = 0.12, respectively). In addition, functional and structural LLDs were not correlated with thoracic Cobb angle (r = 0.09 and r = - 0.05, respectively; p ≥ 0.68 for both).

Conclusions

Although patients with AIS often have functional LLDs, structural LLDs tend to be smaller. The correlation between functional LLDs and the lumbar Cobb angle indicates that functional LLDs compensate for the lumbar curve. Thus, the difference between functional and structural LLDs indicates a compensatory mechanism involving extension and flexion of the lower limbs.

Spondylolysis repair using a pedicle screw hook or claw-hook system. -a comparison of bone fusion rates

Introduction

To assess the bone fusion rates and clinical results of two surgical methods (pedicle screw claw-hook fixation and pedicle screw hook fixation) of lumbar spondylolysis repair.

Methods

A multicenter database of surgical patients with lumbar spondylolysis was reviewed. All patients < 20 years old with a minimum of 6 months of follow-up and computed tomography images were included. Operation time and blood loss amount were investigated. Visual analogue scale (VAS; 0-10) scores for lower back pain were evaluated to assess clinical results.

Results

A total of 17 patients met the inclusion criteria. Pedicle screw hook fixation was performed in five patients (the hook group), and pedicle screw claw-hook fixation was performed in 13 patients (the claw-hook group). One patient was included in both groups because each method was performed at different lumbar levels (L4 and L5). The bone fusion rates at 3, 6, and 9 months after surgery were significantly higher in the claw-hook group than those in the hook group. Operation time and blood loss amount were not significantly different between the groups. VAS scores improved in the claw-hook group but not in the hook group because of a small number of patients.

Conclusions

Pedicle screw claw-hook fixation was more effective than pedicle screw hook fixation in terms of bone fusion rates.

Scoliosis surgery for handicapped children

Introduction

This study aimed to assess treatment outcomes and caregivers' satisfaction regarding scoliosis surgery for handicapped children.

Methods

Handicapped children are, by definition, noncommunicatory and/or nonambulatory. We recruited 26 handicapped children who were followed-up for >1 year after a scoliosis surgery. We recruited 40 patients with adolescent idiopathic scoliosis (AIS) who underwent a surgery during the same period as controls. We used a posterior approach in all the children. We determined preoperative body mass index (BMI), main Cobb angle, Cincinnati correction index (CCI), and fusion level; intraoperative time and blood loss per level; and postoperative complications. We also assessed caregivers' satisfaction with surgical treatments for these patients using the modified Bridwell's questionnaire.

Results

We have described the results as handicapped children/AIS. Median preoperative BMI was 16.1/18.6 kg/m². Preoperative and final Cobb angles were 94.2°/59.7° and 39.7°/17.0°, respectively and CCI was 2.0/1.7. The number of fusion levels was 14.6/9.0. The operative time and blood loss per level were 40.1/44.1 minutes and 264/138 ml, respectively. Postoperative complications in handicapped children were adynamic ileus in 8 cases, dysphagia in 5, pneumonia in 3, urinary tract infection in 2, and superior mesenteric artery syndrome (SMA), surgical site deep infection, infectious enteritis, agitation, and liver dysfunction in 1 each. However, in the AIS group, there was only 1 case of SMA. Median caregivers' satisfaction score on the 0-10 visual analog scale was 9. Caregivers for 19 of the 26 handicapped cases (73%) recommended surgical treatment to caregivers of other children with the same disease.

Conclusions

Surgical treatment for neuromuscular and syndromic scoliosis was associated with a high rate of postoperative complications. However, the caregivers' satisfaction score after surgery was high.

Anatomical etiology of "pseudo-sciatica" from superior cluneal nerve entrapment: a laboratory investigation

Objective

The superior cluneal nerve (SCN) may become entrapped where it pierces the thoracolumbar fascia over the iliac crest; this can cause low back pain (LBP) and referred pain radiating into the posterior thigh, calf, and occasionally the foot, producing the condition known as “pseudo-sciatica.” Because the SCN was thought to be a cutaneous branch of the lumbar dorsal rami, originating from the dorsal roots of L1–L3, previous anatomical studies failed to explain why SCN causes “pseudo-sciatica”. The purpose of the present anatomical study was to better elucidate the anatomy and improve the understanding of “pseudo-sciatica” from SCN entrapment.

Materials and methods

SCN branches were dissected from their origin to termination in subcutaneous tissue in 16 cadavers (5 male and 11 female) with a mean death age of 88 years (range 81–101 years). Special attention was paid to identify SCNs from their emergence from nerve roots and passage through the fascial attachment to the iliac crest.

Results

Eighty-one SCN branches were identified originating from T12 to L5 nerve roots with 13 branches passing through the osteofibrous tunnel. These 13 branches originated from L3 (two sides), L4 (six sides), and L5 (five sides). Ten of the 13 branches showed macroscopic entrapment in the tunnel.

Conclusion

The majority of SCNs at risk of nerve entrapment originated from the lower lumbar nerve. These anatomical results may explain why patients with SCN entrapment often evince leg pain or tingling that mimics sciatica.

Anatomical study of middle cluneal nerve entrapment

Object

Entrapment of the middle cluneal nerve (MCN) under the long posterior sacroiliac ligament (LPSL) is a possible, and underdiagnosed, cause of low-back and/or leg symptoms. To date, detailed anatomical studies of MCN entrapment are few. The purpose of this study was to ascertain, using cadavers, the relationship between the MCN and LPSL and to investigate MCN entrapment.

Methods

A total of 30 hemipelves from 20 cadaveric donors (15 female, 5 male) designated for education or research, were studied by gross anatomical dissection. The age range of the donors at death was 71–101 years with a mean of 88 years. Branches of the MCN were identified under or over the gluteus maximus fascia caudal to the posterior superior iliac spine (PSIS) and traced laterally as far as their finest ramification. Special attention was paid to the relationship between the MCN and LPSL. The distance from the branch of the MCN to the PSIS and to the midline and the diameter of the MCN were measured.

Results

A total of 64 MCN branches were identified in the 30 hemipelves. Of 64 branches, 10 (16%) penetrated the LPSL. The average cephalocaudal distance from the PSIS to where the MCN penetrated the LPSL was 28.5±11.2 mm (9.1–53.7 mm). The distance from the midline was 36.0±6.4 mm (23.5–45.2 mm). The diameter of the MCN branch traversing the LPSL averaged 1.6±0.5 mm (0.5–3.1 mm). Four of the 10 branches penetrating the LPSL had obvious constriction under the ligament.

Conclusion

This is the first anatomical study illustrating MCN entrapment. It is likely that MCN entrapment is not a rare clinical entity.

New radiological parameters for the assessment of atlantoaxial instability in children with Down syndrome

Aims

To determine the normal values and usefulness of the C1/4 space available for spinal cord (SAC) ratio and C1 inclination angle, which are new radiological parameters for assessing atlantoaxial instability in children with Down syndrome.

Patients and Methods

We recruited 272 children with Down syndrome (including 14 who underwent surgical treatment), and 141 children in the control group. All were aged between two and 11 years. The C1/4 SAC ratio, C1 inclination angle, atlas-dens interval (ADI), and SAC were measured in those with Down syndrome, and the C1/4 SAC ratio and C1 inclination angle were measured in the control group.

Results

The mean C1/4 SAC ratio in those requiring surgery with Down syndrome, those with Down syndrome not requiring surgery and controls were 0.63 (standard deviation (sd) 0.1), 1.15 (sd 0.13) and 1.29 (sd 0.14), respectively, and the mean C1 inclination angles were -3.1° (sd 10.7°), 15.8° (sd 7.3) and 17.2° (sd 7.3), in these three groups, respectively. The mean ADI and SAC in those with Down syndrome requiring surgery and those with Down syndrome not requiring surgery were 9.8 mm (sd 2.8) and 4.3 mm (sd 1.0), and 11.1 mm (sd 2.6) and 18.5 mm (sd 2.4), respectively.

Conclusion

The normal values of the C1/4 SAC ratio and the C1 inclination angle were found to be about 1.2° and 15º, respectively. Cite this article: Bone Joint J 2016;98-B:1704–10.

Laminar screw fixation in the subaxial cervical spine: A report on three cases

Although laminar screw fixation is often used at the C2 and C7 levels, only few previous case reports have presented the use of laminar screws at the C3-C6 levels. Here, we report a novel fixation method involving the use of practical laminar screws in the subaxial spine. We used laminar screws in the subaxial cervical spine in two cases to prevent vertebral artery injury and in one case to minimize exposure of the lamina. This laminar screw technique was successful in all three cases with adequate spinal rigidity, which was achieved without complications. The use of laminar screws in the subaxial cervical spine is a useful option for posterior fusion of the cervical spine.

Entrapment of middle cluneal nerves as an unknown cause of low back pain

Entrapment of middle cluneal nerves induces low back pain and leg symptoms. The middle cluneal nerves can become spontaneously entrapped where this nerve pass under the long posterior sacroiliac ligament. A case of severe low back pain, which was completely treated by release of the middle cluneal nerve, was presented. Entrapment of middle cluneal nerves is possibly underdiagnosed cause of low-back and/or leg symptoms. Spinal surgeons should be aware of this clinical entity and avoid unnecessary spinal surgeries and sacroiliac fusion. This paper is to draw attention by pain clinicians in this unrecognized etiology.

Relationship between bone density and bone metabolism in adolescent idiopathic scoliosis

Several authors have confirmed that 27 to 38 % of AIS patients had osteopenia. But few studies have assessed bone metabolism in AIS. This study assessed bone mineral density and bone metabolism in AIS patients using the bone metabolism markers, BAP and TRAP5b. The subjects were 49 consecutive adolescent AIS patients seen at our institutes between March 2012 and September 2013. Sixty-five percent of AIS patients had osteopenia or osteoporosis and 59 % of AIS patients had high values for TRAP5b. The AIS patients with high values of TRAP5b had lower Z scores than those with normal values of TRAP5b. Higher rates of bone resorption are associated with low bone density in AIS patients.

Relationship between bone density and bone metabolism in adolescent idiopathic scoliosis

Several authors have confirmed that 27 to 38% of AIS patients had osteopenia. But few studies have assessed bone metabolism in AIS. This study assessed bone mineral density and bone metabolism in AIS patients using the bone metabolism markers, BAP and TRAP5b. The subjects were 49 consecutive adolescent AIS patients seen at our institutes between March 2012 and September 2013. Sixty-five percent of AIS patients had osteopenia or osteoporosis and 59% of AIS patients had high values for TRAP5b. The AIS patients with high values of TRAP5b had lower Z scores than those with normal values of TRAP5b. Higher rates of bone resorption are associated with low bone density in AIS patients.

Prospective study of superior cluneal nerve disorder as a potential cause of low back pain and leg symptoms

Background

Entrapment of the superior cluneal nerve (SCN) in an osteofibrous tunnel has been reported as a cause of low back pain (LBP). However, there are few reports on the prevalence of SCN disorder and there are several reports only on favorable outcomes of treatment of SCN disorder on LBP. The purposes of this prospective study were to investigate the prevalence of SCN disorder and to characterize clinical manifestations of this clinical entity.

Methods

A total of 834 patients suffering from LBP and/or leg symptoms were enrolled in this study. Diagnostic criteria for suspected SCN disorder were that the maximally tender point was on the posterior iliac crest 70 mm from the midline and that palpation of the tender point reproduced the chief complaint. When patients met both criteria, a nerve block injection was performed. At the initial evaluation, LBP and leg symptoms were assessed by visual analog scale (VAS) score. At 15 min and 1 week after the injection, VAS pain levels were recorded. If insufficient pain decrease or recurrence of pain was observed, injections were repeated weekly up to three times. Surgery was done under microscopy. Operative findings of the SCN and outcomes were recorded.

Results

Of the 834 patients, 113 (14%) met the criteria and were given nerve block injections. Of these, 54 (49%) had leg symptoms. Before injection, the mean VAS score was 68.6 ± 19.2 mm. At 1 week after injection, the mean VAS score significantly decreased to 45.2 ± 28.8 mm (p < 0.05). Ninety-six of the 113 patients (85%) experienced more than a 20 mm decrease of the VAS score following three injections and 77 patients (68%) experienced more than a 50% decrease in the VAS score. Surgery was performed in 19 patients who had intractable symptoms. Complete and almost complete relief of leg symptoms were obtained in five of these surgical patients.

Conclusions

SCN disorder is not a rare clinical entity and should be considered as a cause of chronic LBP or leg pain. Approximately 50% of SCN disorder patients had leg symptoms.

Electronic supplementary material

The online version of this article (doi:10.1186/s13018-014-0139-7) contains supplementary material, which is available to authorized users.

Surgical Treatment of Gorham's Disease with Massive Osteolysis of the Skull and Cervical Spine: A Case Report and Review of Literature

Gorham's disease is a rare disorder of unknown etiology and variable clinical presentation and is characterized by the proliferation of lymphatic vessels associated with massive regional osteolysis. Although 10 cases involving the skull and cervical spine have been reported in the literature, little is available concerning the surgical treatment of either atlantoaxial dislocation or basilar impression. Most cases have experienced universally unsuccessful treatment with bone grafts, which have led to dissolution. This case report describes the clinical course, and radiotherapeutic, medical, and surgical treatment for Gorham's disease with basilar impression and massive osteolysis of the skull and upper cervical spine. The case of a 27-year-old man with progressive massive osteolysis of the skull and cervical spine is reported. Multiple surgical treatments to decompress the spinal cord and stabilize the skull and upper cervical spine with autologous fibular grafts were performed in order to prevent the progression of atlantoaxial dislocation and basilar impression. Pathologically, radiotherapy failed to show any effect. The efficacy of antiresorptive therapy with bisphosphonates could not be confirmed either clinically or radiologically. Although solid bone fusion was not obtained, the patient has achieved a satisfactory functional outcome and remains completely active after repeated surgeries. Surgical treatment is extremely difficult in cases of Gorham's disease involving the skull and upper cervical spine. Fibular bone grafts seem to show resistance to erosion to osteolytic tissue.

Rapid sensitive molecular diagnosis of pyogenic spinal infections using methicillin-resistant Staphylococcus-specific polymerase chain reaction and 16S ribosomal RNA gene-based universal polymerase chain reaction

BACKGROUND CONTEXT

Rapid diagnosis and accurate detection of etiological agents in pyogenic spinal infection (PSI) patients are important.

PURPOSE

The purpose of this study was to evaluate the clinical usefulness of methicillin-resistant Staphylococcus-specific polymerase chain reaction (MRS-PCR) and broad-range universal PCR (U-PCR) for diagnosing PSI.

STUDY DESIGN

A prospective diagnostic study.

PATIENTS

Thirty-two clinically suspect PSI patients and six control patients who underwent computerized tomography-guided biopsy and/or surgical treatment were enrolled.

METHODS

Tissue samples were examined by microbiological culture, histopathology, and real-time PCR (MRS-PCR and U-PCR). The diagnostic accuracy of real-time PCR was analyzed based on the definitive diagnosis of infection, defined as a positive result from microbiological culture or histopathology.

RESULTS

All six control subjects were negative for PSI for all analyses. Twelve clinically suspect PSI subjects received definitive diagnoses (PSI group). The non-PSI group consisted of six control subjects plus the remaining 20 patients from the PSI clinically suspect group. MRS-PCR results were positive for all MRS-cultured PSI subjects. U-PCR was positive for all subjects in the PSI group with one discrepancy between real-time PCR and microbiological culture results in differentiation between gram-positive and gram-negative bacteria. In the non-PSI group, MRS-PCR and U-PCR were positive in three and seven cases, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of MRS-PCR for diagnosing MRS infection were 1.00, 0.91, 0.57, and 1.00, respectively; those for the diagnosis of bacterial infection with U-PCR were 1.00, 0.73, 0.63, and 1.00, respectively.

CONCLUSION

Identification of MRS infection and ability to differentiate between gram-positive and gram-negative bacteria is rapidly achieved using MRS-PCR and U-PCR. Real-time PCR provides a sensitive molecular diagnosis of PSI and may contribute to antibiotic selection.

Pinealectomy in a broiler chicken model impairs endochondral ossification and induces rapid cancellous bone loss

BACKGROUND CONTEXT

Adolescent idiopathic scoliosis (AIS) in humans is a lateral curvature of the spine often associated with osteopenia. It has recently been accepted that the development of AIS is closely associated with spinal overgrowth. Pinealectomy (PNX) in a chicken model consistently induces scoliosis with anatomic features similar to human AIS; however, the mechanism of PNX inducing scoliosis is poorly understood.

PURPOSE

This experimental study attempts to improve the understanding of the mechanisms underlying the onset of scoliosis in a PNX broiler chicken model.

METHODS

A histomorphometric study was performed to analyze longitudinal bone growth and cancellous bone remodeling before the development of scoliosis. Static and dynamic parameters in cancellous bone and chondro-osseous junction of the 7th thoracic vertebral body at 9 days after hatching were compared between PNX chickens (n=9) and control chickens with no surgery (n=5).

RESULTS

PNX resulted in a rapid and marked loss of cancellous bone volume (7.9±0.9% vs. 14.2±1.8%, mean±SD, p<.0005) and profoundly disrupted trabecular structure with increases in dynamic formative parameters, such as mineralizing surface, mineralization apposition rate, and adjusted appositional rate. In the chondro-osseous junction, activated osteoclasts phagocytized degenerating chondrocytes, leaving a minimal amount of cartilage matrix and activated osteoblasts, losing their scaffolding for bone formation, and directly covering the hypertrophic zone cells. The osteoid surface and thickness in the chondro-osseous junction were significantly increased in PNX chickens (43.1±14.2% vs. 11.6±5.7% and 4.1±0.2 μm vs. 2.9±0.4 μm). In the subjacent cartilage regions being protected from further resorption, abundant labeled cartilage remained with higher cellularity.

CONCLUSIONS

It is known that fast-growing birds have a unique paradigm of rapid bone elongation with minimal metaphyseal bone production. A bone-forming surface exists at the front of cartilage ossification in the growth plate; therefore, papillae of hypertrophic chondrocytes become included between the trabeculae of metaphyseal bone and the overall thickness of the growth plate increases considerably in addition to distal expansion. Our results indicate that the unique mechanism for rapid bone elongation in chicken is more pronounced after PNX. PNX also induces high turnover osteoporosis, which may also contribute to the development of scoliosis in the chicken.

Lumbar foraminal stenosis causes leg pain at rest

PURPOSE

Lumbar intra-spinal canal stenosis is characterized by leg pain that intensifies during walking and intermittent claudication, while leg pain at rest is a characteristic neurological symptom of lumbar disc herniation. Until now, a correlation between leg pain at rest and symptomatic foraminal stenosis has not been reported. This is a prospective and comparative study of unilateral leg pain from L5 nerve root compression due to spinal canal stenosis to determine clinical characteristics of lumbar foraminal stenosis.

METHODS

Clinical and neurological findings were compared among 38 patients receiving L5-S1 transforaminal lumbar interbody fusion for L5-S1 foraminal stenosis (FS group) and 60 patients receiving L4-5 decompression or/and fusion for L4-5 intra-spinal canal stenosis (CS group).

RESULTS

The only significant difference between the FS and CS groups in demographic clinical data was leg pain at rest. The prevalence of leg pain was significantly higher in the FS group compared to the CS group (76 vs. 35%). The visual analogue scale for leg pain at rest was also significantly higher in the FS group than in the CS group (6.6 ± 3.1 vs. 1.3 ± 1.9).

CONCLUSIONS

Leg pain at rest is characteristic of L5-S1 foraminal stenosis.

Anatomical study of superior cluneal nerve entrapment

OBJECT

Entrapment of the superior cluneal nerve (SCN) in an osteofibrous tunnel in the space surrounded by the iliac crest and the thoracolumbar fascia is a cause of low-back pain (LBP). Several anatomical and surgical reports describe SCN entrapment as a cause of LBP, and a recent clinical study reported that patients with suspected SCN disorder constitute approximately 10% of the patients suffering from LBP and/or leg symptoms. However, a detailed anatomical study of SCN entrapment is rare. The purpose of this study was to investigate the courses of SCN branches and to ascertain the frequency of SCN entrapment.

METHODS

Branches of the SCN were dissected in 109 usable specimens (54 on the right side and 55 on the left side) obtained in 59 formalin-preserved cadavers (average age at death 84.8 years old). All branches were exposed at the points where they perforated the thoracolumbar fascia. The presence or absence of an osteofibrous tunnel was ascertained and, if present, the entrapment of the branches in the tunnel was determined.

RESULTS

Of 109 specimens, 61 (56%) had at least 1 branch running through an osteofibrous tunnel. Forty-two medial (39%), 30 intermediate (28%), and 14 lateral (13%) SCN branches passed through such a tunnel. Of these, only 2 medial branches had obvious entrapment in an osteofibrous tunnel. There were several patterns for the SCN course through the tunnel: medial branch only (n = 25), intermediate branch only (n = 11), lateral branch only (n = 4), medial and intermediate branches (n = 11), medial and lateral branches (n = 2), intermediate and lateral branches (n = 4), and all branches (n = 4).

CONCLUSIONS

Several anatomical variations of the running patterns of SCN branches were detected. Entrapment was seen only in the medial branches. Although obvious entrapment of the SCN is rare, it may cause LBP.

Clinical results and radiographical evaluation of opening wedge high tibial osteotomy for spontaneous osteonecrosis of the knee

We evaluated the clinical outcomes, in terms of early weight bearing, of using opening wedge high tibial osteotomy (OWHTO) to treat spontaneous osteonecrosis of the medial femoral condyle of the knee (SONK) using TomoFix and artificial bone substitute. Damaged cartilage tissue was removed and drilling of the necrotic area followed by OWHTO was performed in 30 knees from 30 patients with an average age of 71 years (range 58-82) at the time of operation. Patients were allowed to undertake partial weight-bearing exercises 1 week after the osteotomy procedure, with all patients performing full weight-bearing exercise at 2 weeks post-surgery. The mean follow-up period was 40 months (range 24-62). All of the SONK patients could walk with a full weight-bearing load, using only a T-cane, at 2 weeks after undergoing OWHTO. Clinical assays, including the mean American Knee Society Score and Function Score, showed significant improvements from 51 to 93 points, and 58 to 93 points, respectively. Prior to surgery, the average femoro-tibial angle (FTA) during standing was 181 (1 degree anatomical varus) and had significantly changed to 170 (10 degrees valgus) at the time of follow-up. There were no cases of non-union, or implant failure in any of our patients. In addition, none of the patients could sit in the Japanese style prior to surgery, but 21 of 30 patients (70%) could do so after treatment. Arthroscopic findings could be observed in 24 out of 30 cases at implant removal. Necrotic area in each case was covered with fibrous cartilage-like tissue completely. Drilling of the necrotic area followed by OWHTO with TomoFix and artificial bone substitute is an effective treatment for SONK as it results in pain alleviation and regeneration of the fibrous cartilage tissue over the necrotic legion. In addition, an early weight-bearing exercise program is possible after this procedure and full weight-bearing can be achieved at two weeks after surgery.

A predictive factor for acquiring an ideal lower limb realignment after opening-wedge high tibial osteotomy

Obtaining a correct postoperative limb alignment is an important factor in achieving a successful clinical outcome after an opening-wedge high tibial osteotomy (OWHTO). To better predict some of the aspects that impact upon the clinical outcomes following this procedure, including postoperative correction loss and over correction, we examined the changes in the frontal plane of the lower limb in a cohort of patients who had undergone OWHTO using radiography. Forty-two knees from 33 patients (23 cases of osteoarthritis and 10 of osteonecrosis) underwent a valgus realignment OWHTO procedure and were radiographically assessed for changes that occurred pre- and post-surgery. The mean femorotibial angle (FTA) was found to be 182.1 +/- 2.0 degrees (12 +/- 2.0 anatomical varus angulation) preoperatively and 169.6 +/- 2.4 degrees (10.4 +/- 2.4 anatomical valgus angulation) postoperatively. These measurements thus revealed significant changes in the weight bearing line ratio (WBL), femoral axis angle (FA), tibial axis angle (TA), tibia plateau angle (TP), tibia vara angle (TV) and talar tilt angle (TT) following OWHTO. In contrast, no significant change was found in the weight bearing line angle (WBLA) after these treatments. To assess the relationship between the correction angle and these indexes, 42 knees were divided into the following three groups according to the postoperative FTA; a normal correction group (168 degrees < or = FTA < or = 172 degrees ), an over-correction group (FTA < 168 degrees ), and an under-correction group (FTA > 172 degrees ). There were significant differences in the delta angle [DA; calculated as (pre FTA - post FTA) - (pre TV - post TV)] among each group of patients. Our results thus indicate a negative correlation between the DA and preoperative TA (R(2) = 0.148, p < 0.05). Hence, given that the correction errors in our patients appear to negatively correlate with the preoperative TA, postoperative malalignments are likely to be predictable prior to surgery.

Magnetic resonance imaging and magnetic resonance myelography in the presurgical diagnosis of lumbar foraminal stenosis

STUDY DESIGN

Retrospective case series with a control group.

OBJECTIVE

To measure the diagnostic performance of magnetic resonance imaging (MRI) and MR myelography (MRM) for symptomatic foraminal stenosis in patients who need surgery.

SUMMARY OF BACKGROUND DATA

MR images are extensively used in the evaluation of foraminal stenosis and are often used to evaluate nerves exiting from the foramen. There has been no published report of the diagnostic performance of these imaging methods (MRI and MRM).

METHODS

Diagnostic performances were studied in 90 patients in whom the site of the stenosis was confirmed by means of selective decompression surgeries. The disease prevalence among patients was 26% (23 of 90 patients). The disease prevalence among foramens was 3% (25 of 936 foramens). The prevalence of abnormal findings in 27 asymptomatic volunteers was also studied. Two blinded observers interpreted foraminal narrowing on combinations of sagittal and axial MR images, abnormalities of the course of the nerve root in the foramen, and spinal nerve swelling on MRM.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI for the diagnosis of symptomatic foraminal stenosis were 96%, 67%, 4%, and 100%, respectively. The corresponding values for abnormal nerve root course on MRM were 96%, 83%, 7%, and 100%, respectively, and for spinal nerve swelling on MRM were 60%, 99%, 35%, and 99%, respectively.

CONCLUSIONS

Compared with conventional MRI, MRM affords more specific information for the presurgical diagnosis of symptomatic foraminal stenosis.

Comparison of cellular response in bovine intervertebral disc cells and articular chondrocytes: effects .of lipopolysaccharide on proteoglycan metabolism

Lipopolysaccharide (LPS) induces matrix degradation and markedly stimulates the production of several cytokines, i.e., interleukin-1beta, -6, and -10, by disc cells and chondrocytes. We performed a series of experiments to compare cellular responses of cells from the bovine intervertebral disc (nucleus pulposus and annulus fibrosus) and from bovine articular cartilage to LPS. Alginate beads containing cells isolated from bovine intervertebral discs and articular cartilage were cultured with or without LPS in the presence of 10% fetal bovine serum. The DNA content and the rate of proteoglycan synthesis and degradation were determined. In articular chondrocytes, LPS strongly suppressed cell proliferation and proteoglycan synthesis in a dose-dependent manner and stimulated proteoglycan degradation. Compared with articular chondrocytes, nucleus pulposus cells responded in a similar, although less pronounced manner. However, treatment of annulus fibrosus cells with LPS showed no significant effects on proteoglycan synthesis or degradation. A slight, but statistically significant, inhibition of cell proliferation was observed at high concentrations of LPS in annulus fibrosus cells. Thus, LPS suppressed proteoglycan synthesis and stimulated proteoglycan degradation by articular chondrocytes and nucleus pulposus cells. The effects of LPS on annulus fibrosus cells were minor compared with those on the other two cell types. The dissimilar effects of LPS on the various cell types suggest metabolic differences between these cells and may further indicate a divergence in pathways of LPS signaling and a differential sensitivity to exogenous stimuli such as LPS.

Differential effects of fibronectin fragment on proteoglycan metabolism by intervertebral disc cells: a comparison with articular chondrocytes

STUDY DESIGN

This in vitro study used the alginate bead culture system to probe for differences in the effects of fibronectin fragment on cell proliferation and proteoglycan metabolism by different populations of intervertebral disc cells and articular chondrocytes.

OBJECTIVE

To compare the effects of fibronectin fragment on cell proliferation, and proteoglycan synthesis and degradation by cells from the nucleus pulposus, the anulus fibrosus, and articular cartilage.

SUMMARY OF BACKGROUND DATA

In articular cartilage, the administration of fibronectin fragment stimulates cartilage degeneration. Fibronectin fragment levels were increased in human intervertebral discs with increased disc degeneration. Fibronectin fragment injected into the central region of the rabbit intervertebral disc induced a progressive degeneration of that disc.

METHODS

Bovine tails and metacarpophalangeal joints from 14- to 18-month-old animals were used. Alginate beads containing cells isolated from intervertebral discs and articular cartilage were cultured with (1-100 nmol/L) or without (control) fibronectin fragment in the presence of 10% fetal bovine serum. In these cultures, deoxyribonucleic acid and proteoglycan contents, as well as the rate of proteoglycan synthesis were determined. Proteoglycan degradation was measured in cultures with or without 10 nmol/L fibronectin fragment.

RESULTS

In articular chondrocytes, fibronectin fragment strongly suppressed proteoglycan synthesis and stimulated proteoglycan degradation; the total proteoglycan content was diminished in a dose-dependent manner. Compared to articular chondrocytes, nucleus pulposus cells responded to fibronectin fragments in a similar, although less pronounced manner. On the other hand, anulus fibrosus cells treated with fibronectin fragment did not show any significant effects on proteoglycan degradation. A slight but statistically significant up-regulation of proteoglycan synthesis was observed at 10 nmol/L fibronectin fragment in outer anulus fibrosus cells. However, total proteoglycan content was decreased significantly at high concentrations of fibronectin fragment.

CONCLUSIONS

Fibronectin fragment has different effects on cell proliferation, proteoglycan synthesis, degradation, and accumulation by articular chondrocytes and intervertebral disc cells. The different effects of fibronectin fragment in those different cell types suggest metabolic differences between these cells, and may further suggest differences in pathways of fibronectin fragment signaling as well as a differential need of these cells to be involved in tissue remodeling in which both anabolic and catabolic pathways might be altered.

A novel rabbit model of mild, reproducible disc degeneration by an anulus needle puncture: correlation between the degree of disc injury and radiological and histological appearances of disc degeneration

STUDY DESIGN

An in vivo study to radiographically and histologically assess a new method of induction of disc degeneration. OBJECTIVE.: To establish a reproducible rabbit model of disc degeneration by puncturing the anulus with needles of defined gauges and to compare it to the classic stab model.

SUMMARY OF BACKGROUND DATA

New treatment approaches to disc degeneration are of great interest. Although animal models for disc degenerative disease exist, the quantitative measurement of disease progression remains difficult. A reproducible, progressive disc degeneration model, which can be induced in a reasonable time frame, is essential for development of new therapeutic interventions.

METHODS

The classic anular stab model and the new needle puncture model were used in the rabbit. For the needle puncture model, 3 different gauges of needle (16G, 18G, and 21G) were used to induce an injury to the disc to a depth of 5 mm. Radiographic and histologic analyses were performed; magnetic resonance images were also assessed in the needle puncture model.

RESULTS

Significant disc space narrowing was observed as early as 2 weeks after stabbing in the classic stab model; there was no further narrowing of the disc space. In the needle puncture model, all needle sizes tested induced a slower and more progressive decrease in disc height than in the classic stab model. The magnetic resonance imaging supported the results of disc height data.

CONCLUSIONS

The needle puncture approach, using 16G to 21G needles, resulted in a reproducible decrease of disc height and magnetic resonance imaging grade. The ease of the procedure and transfer of the methodology will benefit researchers studying disc degeneration.

Dorsal root ganglia morphologic features in patients with herniation of the nucleus pulposus: assessment using magnetic resonance myelography and clinical correlation

STUDY DESIGN

Morphologic features of the dorsal root ganglia were investigated in patients with herniation of the nucleus pulposus by means of magnetic resonance myelography.

OBJECTIVES

This study was undertaken to assess morphologic changes of the dorsal root ganglia in patients with herniation of the nucleus pulposus and to determine the relations between the morphologic features of the dorsal root ganglia and clinical features.

SUMMARY OF BACKGROUND DATA

It has recently been reported that application of the nucleus pulposus to a nerve root induces edema in the rat dorsal root ganglion. Edema in the human dorsal root ganglion resulting from lumbar disc herniation has not been discussed in the literature, to the authors' knowledge.

METHODS

Eighty-three consecutive patients (average age 42.1 years; range 17 to 77 years) with monoradicular symptoms were examined. Dorsal root ganglion morphologic features, i.e., indentations and swelling, were evaluated by magnetic resonance myelography. The dorsal root ganglion swelling at each level was quantitatively expressed as a ratio of the dorsal root ganglion width on the involved side to that of the contralateral side and was termed dorsal root ganglion ratio. Eighty-three uninvolved levels were chosen as controls in a randomized manner. Factors possibly contributing to the morphologic changes in the dorsal root ganglion were investigated. Neurologic symptoms, evaluated by the Japan Orthopaedic Association scoring system, were correlated to the morphologic changes. The morphologic features were followed up for 1 year after treatment in a small group of patients.

RESULTS

Dorsal root ganglion indentations were always found in the narrowed intervertebral foramens. The incidence of indentations was significantly higher at the involved nerve roots (10.8%) than at the uninvolved nerve roots (4.0%) (P = 0.026). Patients with dorsal root ganglion indentations were significantly older (P = 0.0008). Leg pain scores in patients with indentations were significantly poor (P = 0.007). The dorsal root ganglion ratios were significantly higher at the involved levels than at the uninvolved levels (P = 0.001); the means +/- SD were 1.19 +/- 0.25 and 1.08 +/- 0.13, respectively. Patients with lateral herniated nucleus pulposus had significantly higher dorsal root ganglion ratios than those with central herniated nucleus pulposus (P = 0.0001); the mean ratios +/- SD were 1.48 +/- 0.32 and 1.10 +/- 0.12, respectively. A moderate positive correlation was found between dorsal root ganglion ratio and age (Pearson's correlation coefficient = 0.313). There was moderate negative correlation between the dorsal root ganglion ratio and leg pain, gait, motor, and total Japan Orthopaedic Association score (correlation coefficients were = -0.385, -0.350, -0.422, and -0.358, respectively). The dorsal root ganglion ratios were significantly diminished at 1-year follow-up (P = 0.001); the means +/- SD were 1.22 +/- 0.22 and 1.09 +/- 0.07, respectively. Indentations observed before treatment disappeared after treatment.

CONCLUSIONS

Swelling and impingement in the involved dorsal root ganglion were clearly visualized by magnetic resonance myelography. The swelling and indentations were well correlated with severity of leg pain. These findings have important value in understanding the pathophysiology of the nerve roots in herniated nucleus pulposus.

[Intra-arterial chemotherapy for locally advanced bladder cancer]

A total of 83 patients with locally advanced bladder cancer (T1, n = 5; T2, n = 28; T3a, n = 21; T3b, n = 21; T4, n = 8) were treated with intra-arterial (i.a.) cisplatin and adriamycin (or epirubicin) chemotherapy. In 51 of the 83 cases, we combined this treatment with radiotherapy. The pathological complete response (CR) rate was 68% for all patients, 84% for i.a. chemotherapy combined with radiotherapy and only 41% for i.a. chemotherapy. The 5-year survival rate was 57% for all patients, 71% for i.a. chemotherapy combined with radiotherapy and only 44% for i.a. chemotherapy. The 5-year survival as a function of the clinical stage was 82% for T1 + T2, 66% for T3a, 28% for T3b, 25% for T4 (T1 + T2 vs: T3b: p < 0.001, T1 + T2 vs. T4: p < 0.0001, T3a vs. T3b: p < 0.0263, T3a vs. T4: p < 0.0214, T3b vs. T4: p < 0.029). In 46% of all patients, we succeeded in preserving the bladder; especially noteworthy, is that in 65% of the patients undergoing i.a. chemotherapy combined with radiotherapy, we succeeded in preserving the bladder. These results demonstrate that i.a. chemotherapy combined with radiotherapy is a useful method for locally advanced bladder cancer which may make preservation of the bladder function feasible.

Presurgical identification of extradural nerve root anomalies by coronal fat-suppressed magnetic resonance imaging: a report of six cases and a review of the literature

In an attempt to depict the anatomy of the nerve roots, we obtained magnetic resonance (MR) images of the lumbar spine in the coronal plane with the frequency-selective fat-suppression technique. With this technique, extradural anomalies were identified in 20 (6.7%) of 300 patients. We report the appearance on coronal MR images of six surgically confirmed extradural anomalous nerve roots together with the myelography findings. These include type Ia, type Ib, and type 3 anomalies. These are readily recognized and allow detailed evaluation of the type of nerve root anomaly.

Postfusion instability at the adjacent segments after rigid pedicle screw fixation for degenerative lumbar spinal disorders

Sixty-five patients who underwent wide laminectomy, Cotrel-Dubousset instrumentation, and fusion for lumbar degenerative disorders were reviewed radiographically to investigate the incidence and contributing factors of the postfusion instability at the adjacent segments immediately above or below the level of fusion. Thirty-four were men and 31 were women. The mean age was 55.8 years. The average follow-up time was 39 months. Postfusion instability was studied at a total of 107 adjacent segments in 65 patients. The incidence of postfusion instability noted at final follow-up was 24.6% (15 of 61 patients). The incidence was significantly more often observed in the adjacent segments above the fusion than below the fusion, at rates of 25.5 and 2.6%, respectively. The most common instability was posterior translation (9 of 15 patients). Regarding contributing factors for instability at the adjacent segment above the fusion levels, the age of patients was the most significant factor. The incidence was 36.7% (11 of 30 patients) in older patients (> 55 years old) and 12% (3 of 25 patients) in younger patients (< 55 years old). In four patients with a preoperative of > 3 mm anterior translation, instability progressed further postoperatively. To prevent postoperative instability, attention must be paid especially above the fusion levels of the elderly and the preoperative minimal anterior translation.

Somatoform pain disorder in a case of Klinefelter's syndrome with multiply operated lower back

We report a case of Klinefelter's syndrome with multiply operated low back (MOB). Psychological and/or psychosocial problems related to MOB have been of recent interest in the field of orthopedic surgery. Based on psychiatric interviews, this case was diagnosed as a somatoform pain disorder of the DSM-III-R somatoform disorders. In addition to psychological problems, the pain was partly explicable by severe osteoporosis, which was prematurely caused by endocrinological disturbances associated with Klinefelter's syndrome. Patients with this syndrome are more likely to develop severe osteoporosis. In the presenile period of Klinefelter's syndrome with severe osteoporosis, liaison psychiatrists may pay attention to somatoform disorders (e.g. somatoform pain disorder and conversion disorder) linked with the MO.

Reduction of lumbar spondylolisthesis using a CDI pedicle screw system

To evaluate reduction methods using two of the several types of Cotrel-Dubousset instrumentation (CDI), 39 patients with low-grade (Meyerding grades I and II [12]) lumbar spondylolisthesis were followed clinically and radiologically for a minimum of 6 months. Our surgical methods were classified into three types as follow: reduction by 2-level assembly using double-threaded screws (type I); reduction by single-level assembly using the double-threaded screws (type II); and reduction by single-level assembly using tulip screws (type III). We found that satisfactory reduction could be achieved by single-level assembly using either the double-threaded or tulip screw without resection of disc material or the posterior leverage method. We found that the tulip screw was superior in obtaining stable reduction. We discuss the mechanism of reducing spondylolisthesis in comparison with that of previously reported methods.

Pedicle screws and bone mineral density

STUDY DESIGN

Thirty-five consecutive patients who underwent surgeries for decompression, and one-level fusions with Cotrel-Dubousset pedicle screws for spinal canal stenosis were included in this study. The relationship between bone mineral density of the lumbar spine and the rate of successful fusion and screw problems was studied.

OBJECTIVES

Bone mineral density of the third lumbar vertebral body was measured by quantitative computed tomography preoperatively, and the degree of osteoporosis was graded by radiographic films of lumbar spines. The films were followed with anteroposterior and lateral dynamic radiographic examinations of lumbar spines. These examinations were evaluated clinically after surgery. Follow-up duration was at least 19 months, with a mean of 28 months.

SUMMARY OF BACKGROUND DATA

The mean bone mineral density of all the patients was 117.1 mg/mL (SD = 42.5). The rate of successful fusion was 88.6%, the non-union rate was 5.7%, and the rate of fusions that were undetermined was 5.7%. The incidence of screw loosening occurred in 5.7% of the patients, screw breakage occurred in 5.7% of patients, and symptomatic screws related to non-union were present in 5.7% of patients. The degree of bone mineral density or radiographic gradings of osteoporosis and the successful fusion or the incidence of symptomatic screws, which were defined as screws related to non-union, were not related.

METHODS

The patients were divided into two groups. One group consisted of 12 patients who had less than 100 mg/mL of bone mineral density, with a mean of 72.0 mg/mL (SD = 21.2). The other group consisted of 23 patients who had more than 100 mg/mL of bone mineral density, with a mean of 140.6 mg/mL (SD = 30.0). The rate of successful fusion or non-union and the rate of screw problems such as screw loosening or screw breakage were compared in the two groups. The presence of bony trabeculation in grafted bone is the most important criterion for successful fusion.

RESULTS

A statistical difference did not occur between the two groups. Non-union, screw breakage, and screw loosening were observed in patients with both increased and decreased bone mineral density and those with increased and decreased grade osteoporosis. Radiographic grading of osteoporosis was not correlated to bone mineral density, but patients with unexpected bone mineral density were frequent in this series.

CONCLUSIONS

The use of decompression and pedicle screws for spinal canal stenosis due to degenerative lumbar disorders can be done safely with one-level fusion in patients with decreased bone mineral density if patients with grade III osteoporosis are excluded. Bone mineral density is more reliable than radiographic grading to evaluate the degree of osteoporosis and should be included in the preoperative evaluation of patients with osteoporosis.

Two cases of ganglion cysts in the lumbar spinal canal

Two cases of ganglion cysts in the lumbar spinal canal: MR findings. Ganglion cysts in the spinal canal are rare. To our knowledge, only 12 cases have been reported. In addition, ganglion cysts depicted by MR are extremely rare. We report the MR findings in two cases of ganglion cysts in the lumbar spinal canal. In both cases, the ganglion cysts were slightly higher in intensity than CSF on T2-weighted images. In addition, a thin band of low intensity was depicted around the ganglion in both cases. This finding may help to diagnose ganglion in the spinal canal. On T1-weighted images, the signal intensity of the ganglion was very similar to that of the intervertebral disc in both cases. In summary, although ganglion mimics disc hernia or sequestrated disc on both T2- and T1-weighted images, the possibility of a ganglion should be considered whenever an extradural mass showing high signal intensity surrounded by a thin band of low intensity is identified on T2-weighted images.

[Results of treatment for advanced non-seminomatous germ cell tumors of the testis based on Indiana University classification]

From 1980 to 1990, we treated 45 patients with non-seminomatous germ cell tumors of greater than or equal to stage II according to the Japanese general rule for clinical and pathological studies on testicular tumors. The patients were divided into 2 groups based on the Indiana University Classification: 26 good risk patients (score < or = 6) and 19 poor risk patients (score > or = 7). The clinical results, the % dose intensity of Cisplatin and half-lives of tumor makers were analyzed in the two groups. The per cent dose intensity of Cisplatin of the induction chemotherapy was 61 +/- 24% in 1980-1985 and 87 +/- 18% in 1986-1990. The NED rate improved from 66.7% (10/15) to 81.8% (9/11) in the good risk patients and from 33.3% (3/9) to 50.0% (5/10) in the poor risk patients between the above two periods. When the % dose intensity of Cisplatin exceeded 80%, the NED rate increased from 66.7% (10/15) to 90.0% (9/10) in good risk patients and from 33.3% (2/6) to 45.5% (5/11) in poor risk patients. The NED rate was only 25.0% (4/16) in the poor risk patients whose residual tumors were not resected. The half-lives of AFP and beta-HCG from the latter part of the first course to the second course were 6.8 +/- 1.9 days and 4.4 +/- 1.4 days, respectively, in the patients with a good prognosis, while they were 6.5 +/- 1.5 days and 4.4 +/- 2.9 days, respectively, in with a poor prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Microdiscectomy and second operation for lumbar disc herniation

To prevent recurrence and avoid the second operation, the authors analyzed the clinical features and surgical outcome of 214 patients (157 males and 57 females) who underwent lumbar microdiscectomy, 16 of whom required second operation. The mean age was 34.6 years (range, 12-62 years). The average follow-up period was 4 years 5 months. The overall incidence of second operation was 7.5%. Second operation was performed because of recurrence of herniation in nine patients, and residual bony compression at the lateral recess in two. The incidence of second operation was significantly higher in teenagers than in patients in other age decades (P < 0.01), and in patients with protrusion-type herniation than in those with extrusion-type or sequestration-type herniation (P < 0.01). To prevent the necessity for second operation, careful and thorough discectomy, especially deep to the posterior longitudinal ligament, and decompression at the lateral recess are useful.

[A case of prostatic carcinoma presenting as abdominal mass]

A 69-year-old man was admitted to the hospital on August 7, 1991 because of a lower abdominal mass. On physical examination, firm, rough-surfaced, unmovable masses of over fist size were palpable in the lower abdomen along with some small masses in the bilateral inguinal regions. On rectal examination the prostate was rough, hard and stony and larger than a chicken's egg in size. The serum prostatic acid phosphatase and prostatic specific antigen levels were elevated. A computerized tomography scan disclosed a large mass in the pelvis. Both a needle biopsy of the prostate and resection of an inguinal mass revealed moderately differentiated adenocarcinoma. Bone scintigram disclosed multiple metastases. Treatment with diethylstilbestrol diphosphate, etoposide, peplomycin and ifosfamide was effective, resulting in regressed intrapelvic masses and decreased serum prostatic acid phosphatase and prostatic specific antigen levels close to the normal limits. In November 1991, the patient was discharged and was surviving with the tumor as of August 1992.

[The study on intravesical instillation of THP in the treatment of in-situ and superficial bladder cancers]

The efficacy and safety of Pirarubicin (THP), administered by intravesical instillation, have been studied in recurrent multiple superficial bladder cancer patients and patients who tested positive by urine cytology but lacked protuberant legions (CIS). The average age and range of the 19 patients (M 15, F4) studied were 63.3 (37-84). Twelve patients had protuberant, multiple cancer and 7 patients had CIS. Sixteen of the cases were recurrent disease. Twenty mg THP, delufed in 40 ml of 5% glucose solution were instilled for 2 hours once or twice a week. Each patients received 8 treatments. One week after the last treatment, the therapeutic result was evaluated on the bases of cystoscopy and urine cytology. Before and after administration, CBC and biochemical blood tests were run. Nine of the 12 patients (75%) with multiple recurrent tumor and all the 7 patients with CIS showed complete response. The total outcome for CR was 84.2% in this study. Intravesical instillation with THP did not cause any serious side effects.

[Clinical study of estramustine phosphate (Estracyt) on prostatic cancer]

Clinical effect of Estracyt was investigated in prostatic cancer patients. Twenty seven patients had been previously treated and 20 had not received prior treatment. Improvement rate of subjective symptoms was 85% in the previously untreated patients and that of objective findings was 85%, while those rates were 44% and 50% in the previously treated patients, respectively. Most of the adverse reactions were changes in mamma and mammary papilla which were considered to be due to the estrogenic activity.

[Multivariate evaluation of survival factors and postoperative adjuvant chemotherapy in patients with bladder cancer treated by radical cystectomy]

Multivariate analysis by Cox's proportional hazard model was performed on 71 bladder cancer patients treated by radical cystectomy to clarify factors affecting survival and to evaluate the efficacy of postoperative adjuvant chemotherapy. Clinicopathologic data included in the analysis were age, sex, interval from onset of symptoms to first consultation, prior tumor history, year of operation and tumor characteristics: size, number, growth pattern, stage, grade, mode of infiltration, lymphatic invasion, lymph-node metastasis and lymphocyte infiltration around tumors. Analysis revealed that stage is the most statistically significant factor for survival (p less than 0.0001); followed by year of operation (p less than 0.05) and lymph node metastasis (p less than 0.1). The above three determinants yielded hazard ratios of 16.6 for stage (pT3a-pT4 vs. pTis-pT2), 2.7 for year of operation (1978-1982 vs. 1983-1987) and 2.4 for lymph node metastasis (positive vs. negative). Postoperative adjuvant chemotherapy consisting of cisplatin, peplomycin and mitomycin C (PPM therapy) seemed to improve survival, when the influence of the major prognostic factors were adjusted by the proportional hazards model. The authors conclude that stage and lymph node metastasis should be considered when postoperative adjuvant treatment is selected for patients with bladder cancer treated by radical cystectomy, and that further prospective randomized trials are mandatory to confirm the efficacy of postoperative adjuvant PPM therapy suggested by the present retrospective multivariate analysis.

[A study of postoperative adjuvant chemotherapy of advanced urinary epithelial cancer]

The effect of postoperative adjuvant chemotherapy was studied in 22 cases of advanced urinary epithelial cancer. Vincristine, mitomycin C and bleomycin (VMB) was administered in combination to 9 prophase cases from December, 1980 to March, 1982 and cis-dichlorodiamine platinum, peplomycin and mitomycin C (PPM) in combination to 13 anaphase cases from April, 1982 to November, 1984. The site was renal pelvic cancer in 3 cases, cancer of the ureter in 3 cases, cancer of the bladder in 13 cases, cancer of the pelvis, ureter, and bladder in 1 case, and recurrence of pelvic cancer following bladder cancer in 2 cases. The degree of invasion was pTa in 2 cases, pT1 in 1 case, pT2 in 1 case, pT3 in 11 cases and pT4 in 5 cases. Lymph node metastasis had occurred in 9 cases, no metastasis in 8 cases and it was unclear in the remaining 6 cases. The mean observation period was 16.5 months; 10 patients were alive without any tumors, one patient was alive with a tumor, 11 patients died of cancer, and one patient died intercurrently. The mean postoperative survival period in the mortality cases was 14.5 months. According to the classified type of chemotherapy received, there were 3 out of 9 cases (33.3%) who survived without tumors after receiving VMP and 7 out of 13 cases (53.8%) in the PPM group who survived without tumors. Although a simple comparison cannot be made, it appears that PPM therapy is superior. No severe side-effects were observed.