Anterior lengthening in scoliosis occurs only in the disc and is similar in different types of scoliosis.

Relative anterior spinal overgrowth (RASO) was proposed as a generalized growth disturbance and a potential initiator of adolescent idiopathic scoliosis (AIS). However, anterior lengthening was also observed in neuromuscular (NM) scoliosis, was shown to be restricted to the apical areas and to be located in the intervertebral discs, not in the bone. In this study the goal was to determine if other scoliotic curves of known origin exhibit the similar mechanism of anterior lengthening without changes in the vertebral body. Therefore CT-scans of 18 patients in whom a short segment congenital malformation had led to a long thoracic compensatory curve without bony abnormality were included. Of each vertebral body and intervertebral disc in the compensatory curve, the anterior and posterior length was measured on CT-scans in the exact mid-sagittal plane, corrected for deformity in all three planes. The total AP% of the compensatory curve in congenital scoliosis showed a lordosis (+1.8%) that differed from the kyphosis in non-scoliotic controls (-3.0%; p<0.001), and was comparable to AIS (+1.2%) and NM scoliosis (+0.5%). This anterior lengthening was not located in the bone; the vertebral body AP% showed a kyphosis (-3.2%), similar to non-scoliotic controls (-3.4%), as well as AIS (-2.5%) and NM scoliosis (-4.5%; p=1.000). However, the disc AP% showed a lordosis (+24.3%), which sharply contrasts to the kyphotic discs of controls (-1.5%; p<0.001), but was similar to AIS (+17.5%) and NM scoliosis (+20.5%). The results demonstrate that anterior lengthening is part of the three-dimensional deformity in different types of scoliosis and is exclusively located in the intervertebral discs. The bony vertebral bodies maintain their kyphotic shape, which indicates that there is no active bony overgrowth. Anterior lengthening appears to be a passive result of any scoliotic deformity, rather than being related to the specific cause of AIS.

Clinical and radiological evaluation of Trabecular Metal and the Smith-Robinson technique in anterior cervical fusion for degenerative disease: a prospective, randomized, controlled study with 2-year follow-up.

A prospective, randomized, controlled study was carried out to compare the radiological and clinical outcomes after anterior cervical decompression and fusion (ACDF) with Trabecular Metal (TM) to the traditional Smith-Robinson (SR) procedure with autograft. The clinical results of cervical fusion with autograft from the iliac crest are typically satisfactory, but implications from the donor site are frequently reported. Alternative materials for cervical body interfusion have shown lower fusion rates. Trabecular Metal is a porous tantalum biomaterial with structure and mechanical properties similar to that of trabecular bone and with proven osteoconductivity. As much as 80 consecutive patients planned for ACDF were randomized for fusion with either TM or tricortical autograft from the iliac crest (SR) after discectomy and decompression. Digitized plain radiographic images of 78 (98%) patients were obtained preoperatively and at 2-year follow-up and were subsequently evaluated by two senior radiologists. Fusion/non-fusion was classified by visual evaluation of the A-P and lateral views in forced flexion/extension of the cervical spine and by measuring the mobility between the fused vertebrae. MRI of 20 TM cases at 2 years was successfully used to assess the decompression of the neural structures, but was not helpful in determining fusion/non-fusion. Pain intensity in the neck, arms and pelvis/hip were rated by patients on a visual analog scale (VAS) and neck function was rated using the Neck Disability Index (NDI) the day before surgery and 4, 12 and 24 months postoperatively. Follow-ups at 12 and 24 months were performed by an unbiased observer, when patients also assessed their global outcome. Fusion rate in the SR group was 92%, and in the TM group 69% (P < 0.05). The accuracy of the measurements was calculated to be 2.4 degrees . Operating time was shorter for fusion with TM compared with autograft; mean times were 100 min (SD 18) and 123 min (SD 23), respectively (P = 0.001). The patients' global assessments of their neck and arm symptoms 2 years postoperatively for the TM group were rated as 79% much better or better after fusion with TM and 75% using autograft. Pain scores and NDI scores were significantly improved in both groups when compared with baseline at all follow-ups, except for neck pain at 1 year for the TM group. There was no statistically significant difference in clinical outcomes between fusion techniques or between patients who appeared radiologically fused or non-fused. There was no difference in pelvic/hip pain between patients operated on with or without autograft. In our study, Trabecular Metal showed a lower fusion rate than the Smith-Robinson technique with autograft after single-level anterior cervical fusion without plating. There was no difference in clinical outcomes between the groups. The operative time was shorter with Trabecular Metal implants.

Prognostic value of flow cytometry and correlation to some conventional prognostic factors: a retrospective study of archival specimens of 134 astrocytomas.

The S-phase fraction and the DNA ploidy type in 134 astrocytomas (18 Grade II, 46 Grade III, and 70 Grade IV astrocytomas) were studied using flow cytometry in a retrospective study of archival tumor specimens. A high grade of malignancy was associated with both a high S-phase fraction (p < 0.0001) and an aneuploid DNA pattern (p < 0.0001). There was no aneuploid DNA pattern found in the fibrillary astrocytomas (World Health Organization (WHO) Grade II); where-as the aneuploid pattern was observed in 80% of all the glioblastomas multiforme (WHO Grade IV). The age and gender of the patients were not significantly related to the flow cytometry parameters. The survival of patients with Grade II or III astrocytomas was significantly longer when their tumors exhibited a tetraploid DNA pattern or had a low S-phase fraction. In patients with Grade IV tumors, there was no correlation between length of survival and either the DNA ploidy or the S-phase fraction. In a multivariate Cox regression analysis of data obtained in patients with Grade II and III astrocytomas, age, grade of malignancy, DNA ploidy, and S-phase fraction were independent prognostic factors.

DNA index and S-phase in primary brain tumors. A comparison between fresh and deparaffinized specimens studied by flow cytometry.

Forty-nine primary intracranial tumors (33 astrocytomas, eight acoustic schwannomas, five oligodendrogliomas, and three miscellaneous tumors) were studied by flow cytometry. Each tumor specimen was divided into two portions: one was studied as an unfixed suspension stained with propidium iodide and the other after formalin fixation and paraffin embedding. The 50-microns sections from the paraffin blocks were deparaffinized, rehydrated, and enzymatically disintegrated, and the cells in suspension were stained with propidium iodide. Flow cytometry of the two portions showed a significant correlation between fresh and fixed specimens regarding the S-phase (r = 0.87) and a very close correlation fo the deoxyribonucleic acid (DNA) index (r = 0.95). When the 33 astrocytomas were analyzed separately, similar results were obtained (r = 0.86 for S-phase and r = 0.93 for DNA index, respectively). This study demonstrated a high correlation between fresh and fixed specimens for DNA ploidy and S-phase both in primary intracranial tumors in general and also in the selected subgroup of astrocytomas.

Ki-67 antigen expression as a prognostic factor in primary and recurrent astrocytomas.

BACKGROUND AND PURPOSE: Histological grading is widely used to evaluate the prognosis for patients with astrocytic tumors. Many complimentary methods have been introduced, such as proliferation markers in order to better assess the proliferative potential of these gliomas. METHODS: Archival, paraffin embedded specimens of recurrent astrocytic tumors of varying grades from 22 patients were examined using antibodies against Ki-67 (MIB-1). Labeling indices (LI) were analyzed at the first and second operations and compared with tumor grades, age of the patients and the time between the operations as well as the survival time. RESULTS: There was a progression of malignancy between the operations. Dividing Ki-67 labeling indices in < or = 10% vs. > 10% significantly separated parameters such as the time between the first operation and relapse as well as the cumulative proportion of survival. The proliferation fraction was an independent prognostic factor. CONCLUSION: Assessment of Ki-67 LI is highly recommended in addition to histology in evaluation of the malignancy potential of astrocytic tumors.

Predictive factors for arm pain, neck pain, neck specific disability and health after anterior cervical decompression and fusion.

BACKGROUND: Predictive factors for a low arm and neck pain, and good health after anterior cervical decompression and fusion (ACDF) with a cervical carbon fibre intervertebral fusion cage (CIFC) are still lacking. METHOD: A prospective consecutive study to investigate which preoperative factors that could predict a good outcome with regard to arm pain, neck pain, Neck Disability Index (NDI) and general health three years after ACDF with CIFC was conducted. Thirty-four patients were included before surgery. Measurements took place the day before, six months, one year and three years after ACDF. FINDINGS: In multivariate analysis, to be a non-smoker before surgery was the most important factor for a low postoperative arm pain, a low pain frequency was the most important factor for low postoperative neck pain, normal rating on Distress and Risk Assessment Method (DRAM) was the most important factor for high function on NDI and a low initial pain intensity was the most important factor for good postoperative health. For all outcome variables a normal rating on DRAM was an important factor for a good outcome. CONCLUSIONS: Non-smoking, a low pain level and normal rating on DRAM were the best preoperative predictors of a good outcome in ACDF. Inclusion criteria for surgery should be based on a bio psychosocial model and DRAM seems to be useful for including the traditional inclusion criteria.

The use of ultrasonic aspirator, Sonocut, for removal of brain tumours. Analysis of 26 consecutive cases.

Since the introduction of the ultrasonic aspirator system in 1978, there have been several reports on its efficacy and safety in neurosurgery. During the last six months we have used in our department the swedish manufactured device Sonocut for removal of various tumours within the central nervous system. Its benefits and limitations are discussed. Evaluation of the histological appearance of tissues removed by the aspirator versus conventional technics is presented.

DNA ploidy and S-phase in recurrent astrocytomas: a retrospective study by flow cytometry of deparaffinized specimens.

Twenty-two patients with recurrent astrocytic tumors were treated surgically two or even three times. At the time of the first surgery 6 tumors were fibrillary astrocytomas (grade II), 9 anaplastic astrocytomas (grade III) and 7 glioblastomas (grade IV). Histopathological specimens from second surgery demonstrated in 12 cases signs of higher grades of malignancy. Flow cytometry (FCM) did not reveal any significant changes of S-phase fraction (p = 0.55). This study supports the theory that, given enough time, the histopathology of brain tumors change significantly from more benign forms to more malignant ones. The flow cytometry (FCM) could trace a weak tendency to higher S-phase fractions at the time of the second surgery. No apparent change of ploidy pattern was observed. In spite of the unequivocal histopathological changes of the recurrent astrocytomas the flow cytometry failed to indicate similar changes in terms of ploidy and S-phase fraction parameters.

Local anesthesia prevents hypertension following application of the Mayfield skull-pin head holder.

A marked hypertensive response is often seen when the Mayfield skull-pin device is applied to stabilize the head of the anesthetized patient for neurosurgery. In a prospective, blinded and randomized trial, 10 patients received an infiltration block of 0.5% mepivacaine with epinephrine 5 micrograms/ml (3 ml at each pin site) 1 min before the Mayfield holder was applied. Ten patients received normal saline and served as controls. All patients were under general anesthesia induced with sodium pentothal, fentanyl and pancuronium, and maintained with isoflurane in nitrous oxide/oxygen and increments of fentanyl. In the control group, there were significant increases in mean arterial pressure (mean increase 43%, P less than 0.001) and heart rate (15%, P less than 0.01) at 0.5, 1 and 2 min after application. In the mepivacaine group, no significant changes occurred. Infiltration of local anesthetic with epinephrine can thus safely protect against potentially dangerous increases in arterial pressure when the Mayfield holder is used.

Is the efficacy of the Cloward procedure overestimated? Technique of evaluation affects the outcome.

The purpose of the present study was to investigate the influence of the evaluation technique on the outcome of the Cloward procedure in cervical radiculopathy. The retrospective study included 94 consecutive patients operated on with anterior decompression and fusion with heterologous bone (Surgibone, Unilab). There were 56 men and 38 women, with a mean age of 48 years (range 27-78 years). Sixty-six patients had a single-level fusion, 26 a two-level fusion and one patient had a three-level fusion. The follow-up rate was 91/94 (97%) and evaluation was performed by an independent observer. Pain was quantified by visual analogue scale (VAS, range 0-100), functional disability by the new functional index Cervical Spine Functional Score (CSFS, range 0-100) and by the Neck Pain Disability Index (NPDI, range 0-100). The overall clinical outcome was assessed as excellent, good, fair or poor by both the patient and by the independent observer using Odom's criteria. At a mean follow-up of 26 months (range 12-56 months) the mean pain index was 39 (range 0-98), the mean CSFS 39 (range 0-85) and the mean NPDI 32 (range 0-76). The classification of the observer was 37% excellent, 40% good, 17% fair and 6% poor, and that of the patient was 53% excellent, 23% good, 20% fair and 4% poor. In the group classified as good by the observer, all scores were above 40, suggesting considerable remaining symptoms, and only 50% had returned to work. The results suggest that previous reports on the Cloward procedure using categorizations into excellent, good, fair or poor have overestimated the efficacy of the procedure. Only an excellent, but not a good, result as classified by the patient or an independent observer reflects a successful outcome. Neither of the variables studied seems independently sufficient for a balanced reflection of the outcome. The results suggest pain (VAS) as the primary outcome measurement, which, combined with the overall evaluation by the independent observer and work status, gives a multidimensional expression of the outcome.

Microvascular decompression for trigeminal neuralgia.

An analysis of 57 patients with trigeminal neuralgia (TN) treated with microvascular decompression (MVD) is presented. Mean follow-up time was 3.1 years. Vascular compression of the trigeminal nerve root was noted in 54 cases. In the remaining 3 patients, adhesions were observed in two, whereas no obvious cause was found in one case. Among the patients with vascular compression, 43 (80%) became painfree immediately after surgery, and have remained so during the observation period. There was an indisputable relationship between the degree of observed vascular compression of the nerve and long-term complete pain relief. There was no mortality in association with the surgery. Major morbidity was seen in 3.6%, and partial facial sensory loss was seen in seven patients (12%). The implications of these findings are discussed.

Degenerative changes following anterior cervical discectomy and fusion evaluated by fast spin-echo MR imaging.

PURPOSE: To review pre- and postoperative fast spin-echo (FSE) MR images of disc herniation and spondylosis in patients after spinal cervical surgery. MATERIAL AND METHODS: Data were reviewed of 68 patients after anterior discectomy and fusion (ADF) operations using the Cloward technique with solid single level (C5-C6 or C6-C7) or 2-level fusions (C5-C7). The average interval from surgery to review was 37 months. Age- and sex-matched controls without neck problems were examined. RESULTS: Preoperatively, the fusion groups had a higher incidence of protruded disc, and anterior and posterior osteophytes at the levels to be fused than the controls. Post-operatively, there was a significantly higher incidence of posterior osteophytes at the fused levels compared with the controls. Furthermore, the disc herniations and anterior osteophytes at the levels above and below the operated segments were more frequent in the fusion group. CONCLUSION: ADF causes acceleration of the degenerative changes at the fused level and at the levels below and above the fused segments.

Fast spin-echo MR assessment of patients with poor outcome following spinal cervical surgery.

PURPOSE: The aim of the investigation was to evaluate poor outcome following spinal and cervical surgery. MATERIAL AND METHODS: A total of 146 consecutive patients operated with anterior discectomy and fusion (ADF) with the Cloward technique were investigated. Clinical notes, plain radiography, CT, and fast spin-echo (FSE) images were retrospectively evaluated. RESULTS: Some 30% of the patients had unsatisfactory clinical results within 12 months after surgery; 13% had initial improvement followed by deterioration of the preoperative symptoms, while 14.4% were not improved or worsened. Disc herniation and bony stenosis above, below, or at the fused level were the most common findings. In 45% of patients, surgery failed to decompress the spinal canal. In only 4 patients was no cause of remaining myelopathy and/or radiculopathy found. FSE demonstrated a large variety of pathological findings in the patients with poor clinical outcome after ADF. Postoperatively, patients with good clinical outcome had a lower incidence of pathological changes. CONCLUSION: FSE is considered the primary imaging modality for the cervical spine. However, CT is a useful complement in the axial projection to visualize bone changes.