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N Boos

Publications and source records attributed to N Boos.

At least 19 recordsLinked to original sources
PubMed2002

2002 SSE Award Competition in Basic Science: expression of major matrix metalloproteinases is associated with intervertebral disc degradation and resorption.

During the process of degeneration, the intervertebral disc (IVD) shows a progressive and significant reduction in height due to tissue resorption. Intradiscal clefts and tears are major hallmarks of disc degeneration. Matrix-degrading enzymes such as matrix metalloproteinases (MMPs) are assumed to play a pivotal role in disc tissue degradation and resorption. The objective of this study was therefore to investigate the potential role of MMPs in extracellular matrix degradation leading to disc degeneration. This study was conducted on 30 formalin-fixed and EDTA-decalcified complete cross-sections of lumbar IVDs from cadavers of individuals aged between 0 and 86 years. Tissue sections were used for the immunolocalization of MMPs-1, -2, -3 and -9. The number of labeled cells was assessed by morphometric analyses, and was statistically correlated with the formation of clefts and tears, cellular proliferation, granular matrix changes and mucous degeneration. Furthermore, 30 disc specimens obtained during spinal surgery were used for in situ hybridization of MMP-2 and -3-mRNA. In addition, the enzymatic gelatinolytic activity was determined by in situ zymography in autopsy material. Immunohistochemistry showed the intradiscal expression of all four MMPs, which was confirmed by in situ hybridization, providing clear evidence for the synthesis of the enzymes within nucleus pulposus and annulus fibrosus cells. Gelatinolytic enzymatic activity was verified by in situ zymography. IVDs from infants and young adolescents remained almost completely unlabeled for all MMPs tested, while more MMPs-1 and -3 were seen in disc cells of younger adults than in those of a more advanced age; MMP-2 remained unchanged over the adult age periods, and MMP-9 was expressed in only relatively few cells. This pattern significantly correlated with the occurrence of clefts and tears. This correlation was strongest for MMP-1 ( P<0.0001), MMP-2 ( P<0.0017) and MMP-3 ( P<0.0005) in the nucleus, and MMP-1 ( P<0.0001) and MMP-2 ( P<0.038) in the annulus. In parallel, the proliferation of disc cells and matrix degeneration (granular changes and mucous degeneration) were related to MMP expression. Likewise, enzymatic activity was seen in association with cleft formation. Our data suggest that major MMPs play an important role in the degradation of the IVD. This is evidenced by the high correlation of MMP expression with the formation of clefts and tears. These findings implicate a leading function for MMPs in IVD degeneration resulting in the loss of normal disc function, eventually leading to low-back pain.

Adolescent↗
PubMed2002

[Percutaneous transpedicular vertebroplasty for treatment of osteoporosis-induced vertebral fractures].

Osteoporosis plays an increasing medical, social, and economic role in our society. Vertebral body fractures are the most common fractures, along with fractures around the hip joint, and fractures of the distal radius due to osteoporosis. An osteoporotic vertebral compression fracture can lead to incapacitating back pain and immobility and often requires in-hospital treatment. Vertebroplasty is an effective procedure consisting of the percutaneous injection of polymethylmethacrylate (PMMA) cement into vertebral bodies. Preliminary studies showed promising clinical results with this new technique. As there is a high incidence of cement leakage during the injection of the cement, we prefer to perform the procedure under computed tomography control with a fluoro-CT-option. Furthermore, we recommend that the procedure is only done in collaboration with a spine surgeon. In case of a neurological complication, immediate decompression of the spinal canal is mandatory. Vertebroplasty is a very promising, effective and safe method for the treatment for osteoporotic vertebral compression fractures. Based on our preliminary results, this method can be recommended for a more widespread clinical use.

Administration, Cutaneous↗
PubMed2001

Magnetic resonance classification of lumbar intervertebral disc degeneration.

STUDY DESIGN: A reliability study was conducted. OBJECTIVES: To develop a classification system for lumbar disc degeneration based on routine magnetic resonance imaging, to investigate the applicability of a simple algorithm, and to assess the reliability of this classification system. SUMMARY OF BACKGROUND DATA: A standardized nomenclature in the assessment of disc abnormalities is a prerequisite for a comparison of data from different investigations. The reliability of the assessment has a crucial influence on the validity of the data. Grading systems of disc degeneration based on state of the art magnetic resonance imaging and corresponding reproducibility studies currently are sparse. METHODS: A grading system for lumbar disc degeneration was developed on the basis of the literature. An algorithm to assess the grading was developed and optimized by reviewing lumbar magnetic resonance examinations. The reliability of the algorithm in depicting intervertebral disc alterations was tested on the magnetic resonance images of 300 lumbar intervertebral discs in 60 patients (33 men and 27 women) with a mean age of 40 years (range, 10-83 years). All scans were analyzed independently by three observers. Intra- and interobserver reliabilities were assessed by calculating kappa statistics. RESULTS: There were 14 Grade I, 82 Grade II, 72 Grade III, 68 Grade IV, and 64 Grade V discs. The kappa coefficients for intra- and interobserver agreement were substantial to excellent: intraobserver (kappa range, 0.84-0.90) and interobserver (kappa range, 0.69-0.81). Complete agreement was obtained, on the average, in 83.8% of all the discs. A difference of one grade occurred in 15.9% and a difference of two or more grades in 1.3% of all the cases. CONCLUSION: Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation.

Algorithms↗
PubMed2001

Therapeutic efficacy of selective nerve root blocks in the treatment of lumbar radicular leg pain.

The objective of this study was to investigate the clinical effectiveness of nerve root blocks (i.e., periradicular injection of bupivacaine and triamcinolone) for lumbar monoradiculopathy in patients with a mild neurological deficit. We have retrospectively analysed 30 patients (29-82 years) with a minor sensory/motor deficit and an unequivocal MRI finding (20 disc herniations, 10 foraminal stenoses) treated with a selective nerve root block. Based on the clinical and imaging findings, surgery (decompression of the nerve root) was justifiable in all cases. Twenty-six patients (87%) had rapid (1-4 days) and substantial regression of pain, five required a repeat injection. 60% of the patients with disc herniation or foraminal stenosis had permanent resolution of pain, so that an operation was avoided over an average of 16 months (6-23 months) follow-up. Nerve root blocks are very effective in the non-operative treatment of minor monoradiculopathy and should be recommended as the initial treatment of choice for this condition.

Adult↗
PubMed2001

Retroperitoneal endoscopically assisted minilaparotomy for anterior lumbar interbody fusion: technical feasibility and complications.

STUDY DESIGN: Description of a novel less invasive technique and prospective evaluation of associated morbidity and potential complications. OBJECTIVE: To investigate the feasibility of a novel endoscope-assisted retroperitoneal approach (REAM) for anterior lumbar interbody fusion (ALIF). SUMMARY OF BACKGROUND DATA: Minimally and less invasive approaches are currently favored to perform ALIF. However, the present endoscopic techniques have not found widespread acceptance, because they are technically demanding, and microsurgical techniques are not time effective when two separate approaches are needed for L5-S1 (transperitoneal) and L4-L5 (retroperitoneal). METHODS: The authors have developed the technique of REAM, which consists of three stages: 1) endoscopic retroperitoneal mobilization of the peritoneal sac, 2) midline minilaparotomy (4-6 cm), and 3) standard open anterior lumbar interbody fusion. Twenty patients were prospectively enrolled in this study and perioperative data (i.e., blood loss, operative time, intra- and postoperative complications) were collected to assess the feasibility of this approach. RESULTS: Six single-level and 14 two-level ALIFs from L3-L4 to L5-S1 were performed with a mean operative time of 108 minutes (range, 85-150) and an average estimated blood loss of 200 mL (range, 50-500). The follow-up (range, 12-29 months) on 20 patients showed that there were no perioperative or postoperative complications related directly to this approach. CONCLUSION: Anterior lumbar interbody fusion by REAM can be performed without additional hazard to the patient and appears to be a reasonable alternative to existing less invasive procedures.

Endoscopy↗
PubMed2001

Selective nerve root blocks for the treatment of sciatica: evaluation of injection site and effectiveness--a study with patients and cadavers.

PURPOSE: To relate different types of radiographic contrast material distributions to anatomic compartments by using cadaveric specimens and to relate the injection site to treatment-induced discomfort and therapeutic effect. MATERIALS AND METHODS: The contrast material distributions of selective nerve root blocks (SNRBs) in 36 patients (13 women, 23 men; mean age, 52 years; age range, 22-88 years) were graded by two radiologists in conference as type 1 (tubular appearance), type 2 (nerve root visible as filling defect), or type 3 (nerve root not visible). These patterns were correlated with pain reduction after 15 minutes and 2 weeks (with a visual analogue scale of 100-mm length). In addition, 30 nerve roots were injected with iodine-containing contrast material and blue dye in three cadaveric specimens. Radiographs were compared with anatomic sections. RESULTS: After 15 minutes and 2 weeks, 75% and 86% of the patients, respectively, reported pain relief. Mean pain relief length after 15 minutes for type 1 distribution was 60 mm; for type 2, 44 mm; and for type 3, 22 mm; and after 2 weeks, it was 34 mm for type 1, 31 mm for type 2, and 57 mm for type 3. There was no correlation between early and late response. Pain during intervention was less pronounced in type 2 injection, compared with type 1 (P = .002). On the basis of anatomic sections, type 1 injection was intraepineural; type 2, extraepineural; and type 3, paraneural. CONCLUSION: Therapeutic SNRB is effective in sciatica, but early response does not predict the effect after 2 weeks. Type 1 injections are more painful than type 2 injections.

Adult↗
PubMed2001

MR morphology of alar ligaments and occipitoatlantoaxial joints: study in 50 asymptomatic subjects.

PURPOSE: To assess the magnetic resonance (MR) imaging appearance of the alar ligaments and joints in the upper cervical spine to determine the prevalence of structural alterations in asymptomatic individuals. MATERIALS AND METHODS: Fifty healthy individuals (31 men, 19 women) with a mean age of 30 years (range, 19-47 years) underwent coronal T1- and T2-weighted and transverse T1-weighted MR imaging. MR findings were analyzed independently by two musculoskeletal radiologists, with disagreements resolved in conference. RESULTS: Alar ligaments were detected in 42 (84%) (left side) and 38 (76%) (right side) of 50 individuals. The majority of ligaments (88%) and joints (58%) of the craniocervical junction (CCJ) were asymmetric. Asymmetry of the joint between C1 and C2 was less frequent (46%). Small amounts of fluid were detected in 8% of CCJ joints and 56% of C1-C2 joints in asymptomatic individuals. CONCLUSION: Asymmetry of alar ligaments, CCJ and C1-C2 facet joints, and joint effusions are common in asymptomatic individuals. The clinical relevance of these MR findings is therefore limited in the identification of the source of neck pain in symptomatic patients.

Adult↗
PubMed2001

Painful Lumbar Disk Derangement: Relevance of Endplate Abnormalities at MR Imaging.

PURPOSE: To investigate the predictive value of magnetic resonance (MR) imaging of abnormalities of the lumbar intervertebral disks, particularly with adjacent endplate changes, to predict symptomatic disk derangement, with discography as the standard. MATERIALS AND METHODS: Fifty patients aged 28-50 years with chronic low back pain and without radicular leg pain underwent prospective clinical examination and sagittal T1- and T2-weighted and transverse T2-weighted MR imaging. Subsequently, patients underwent lumbar discography with a pain provocation test (116 disks). MR images were evaluated for disk degeneration, a high-signal-intensity zone, and endplate abnormalities. Results of pain provocation at discography were rated independently of the image findings as concordant or as nonconcordant or painless. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to assess the clinical relevance of MR abnormalities. RESULTS: Normal disks on MR images were generally not painful at provocative discography (NPV, 98%). Disk degeneration (sensitivity, 98%; specificity, 59%; PPV, 63%) and a high-signal-intensity zone (sensitivity, 27%; specificity, 85%; PPV, 56%) were not helpful in the identification of symptomatic disk derangement. When only moderate and severe type I and type II endplate abnormalities were considered abnormal, all injected disks caused concordant pain with provocation (sensitivity, 38%; specificity, 100%; PPV, 100%). CONCLUSION: Moderate and severe endplate abnormalities appear be useful in the prediction of painful disk derangement in patients with symptomatic low back pain.

Adult↗
PubMed2000

Natural history of individuals with asymptomatic disc abnormalities in magnetic resonance imaging: predictors of low back pain-related medical consultation and work incapacity.

STUDY DESIGN: Prospective study on individuals with asymptomatic lumbar disc abnormalities detected in magnetic resonance imaging. OBJECTIVES: To determine the natural history of asymptomatic disc abnormalities in magnetic resonance imaging and to identify predictors of future low back pain-related medical consultation and work incapacity. SUMMARY OF BACKGROUND DATA: The natural history of individuals with asymptomatic disc herniations has not been well established, but the high rate of lumbar disc alterations recently detected in asymptomatic individuals by magnetic resonance imaging demands reconsideration of a pathomorphology-based explanation of low back pain and sciatica. METHODS: Forty-six asymptomatic individuals who had a high rate of disc herniations (73%) were observed for an average of 5 years (range, 54-72 months). Four classes of variables (medical data including magnetic resonance imaging-identified disc abnormalities, general psychological factors, physical job characteristics, and psychosocial aspects of work) were assessed at baseline and follow-up. RESULTS: Disc herniations and neural compromise did not significantly worsen at follow-up, whereas disc degeneration progressed in 17 individuals (41.5%). Minor episodes of low back pain occurred in 19 individuals (41.3%), 6 of whom had to seek medical treatment and 5 of whom had to stop work temporarily. The requirement for low back pain-related medical consultation was predicted with high accuracy by listlessness, job satisfaction, and working in shifts (P < 0.001). Work incapacity was best predicted by physical job characteristics, job disaffection, and working in shifts (P < 0.01). CONCLUSION: Physical job characteristics and psychological aspects of work were more powerful than magnetic resonance imaging-identified disc abnormalities in predicting the need for low back pain-related medical consultation and the resultant work incapacity. However,the conclusions are still preliminary, and replication of the findings in larger and more representative study samples is needed.

Adult↗
PubMed2000

[Acute myelopathy and cauda equina syndrome].

The high incidence of non-specific, benign back trouble often delays the diagnosis of specific causes of back pain and thus result in neurological deficits. Degenerative abnormalities in the cervical spine may narrow the spinal canal and result in acute myelopathy subsequent to minor injuries. Large cervical or lumbar disc herniations causing myelon, conus or cauda equina compression are rare but must not be overlooked. Spinal metastases may remain unrecognised for a long period and lead to the correct diagnosis only after presentation with neurological deficits. Acute myelopathy or cauda equina syndrome are indications for immediate diagnostic assessment and treatment in a spine centre.

Acute Disease↗
PubMed2000

Functional MR imaging of the craniocervical junction. Correlation with alar ligaments and occipito-atlantoaxial joint morphology: a study in 50 asymptomatic subjects.

PURPOSE: Whiplash injuries are frequent in industrialized countries. The acute and chronic symptoms following such injuries are incompletely understood and objective clinical or imaging findings are rare. Several authors have suspected that rear end collisions occurring when the head is rotated may result in tears of the alar ligaments. There has been experimental proof that a torn alar ligament increases the rotation of the C0/C1 and C1/C2 segments to the contralateral side. Functional cross sectional imaging has therefore been proposed to diagnose injuries of the alar ligaments. So far, published data on normal ranges of rotation in an asymptomatic population have been sparse. The aim of this study was to determine by MR imaging the normal range of rotation in the first three cervical segments and their relation to the morphology of the alar ligaments and the occipito-atlantoaxial joints. MATERIAL AND METHODS: Functional MR imaging of the craniocervical junction in maximum active left and right head rotation was performed in 50 healthy volunteers with a mean age of 29.8 years (31 men, 19 women, range 19-47 years). Measurements were independently performed by two musculoskeletal radiologists to assess interobserver error. The results were correlated with gender and age, with morphological findings in the occipito-atlantoaxial joints (i.e. joint symmetry, joint effusions, dens position), and with the form, course and symmetry of the alar ligaments. RESULTS: The mean range of rotation for the C0/C1 joint was 2.7 degrees (standard deviation [SD] 3.3 degrees)/3.3 degrees (SD 3.6 degrees) (right/left) and at the C1/C2 level 38 degrees (SD 6.5 degrees)/37.8 degrees (SD 6.4 degrees). The mean differences in left/right rotation were: C0/C1 3.5 degrees (SD 2.8 degrees) and C1/C2 6.3 degrees (SD 4.4 degrees). No correlation was found between segmental rotation and morphological characteristics of the craniocervical joints or ligament structures. CONCLUSION: There is wide variation of segmental motion in the upper cervical spine. Differences in right-to-left rotation are frequently encountered in an asymptomatic population. Therefore, these measurements are unsuitable for indirect diagnosis of soft tissue lesions after whiplash injury and should not be used as a basis for treatment guidelines.

Adult↗
PubMed2000

Positional MR imaging of the lumbar spine: does it demonstrate nerve root compromise not visible at conventional MR imaging?

PURPOSE: To evaluate whether positional magnetic resonance (MR) images of the lumbar spine demonstrate nerve root compromise not visible on MR images obtained with the patient in a supine position (conventional MR images). MATERIALS AND METHODS: Thirty patients with chronic low back pain unresponsive to nonsurgical treatment and with disk abnormalities but without compression of neural structures were included. Positional MR images were obtained by using an open-configuration, 0.5-T MR imager with the patients seated and with flexion and extension of their backs. The disk and nerve root were related to the body position. Nerve root compression and foraminal size were correlated with the patient's symptoms, as assessed with a visual analogue scale. RESULTS: Nerve root contact without deviation was present in 34 of 152 instances in the supine position, in 62 instances in the seated flexion position, and in 45 instances in the seated extension position. As compared with the supine position, in the seated flexion position nerve root deviation decreased from 10 to eight instances; in the seated extension position, it increased from 10 to 13 instances. Nerve root compression was seen in one patient in the seated extension position. Positional pain score differences were significantly related to changes in foraminal size (P =.046) but not to differences in nerve root compromise. CONCLUSION: Positional MR imaging more frequently demonstrates minor neural compromise than does conventional MR imaging. Positional pain differences are related to position-dependent changes in foraminal size.

Adult↗
PubMed2000

Subacute subdural haematoma complicating lumbar microdiscectomy.

There have been no previous reports of a spinal subdural haematoma occurring as a complication of spinal surgery. We highlight the pitfalls in the diagnosis and management of a subacute subdural haematoma resulting from a dural tear which occurred as a surgical complication of microdiscectomy.

Aged↗
PubMed1999

[Diagnostic assessment in lumbar back pain. I. Anamnesis and clinical examination].

The diagnostic assessment of the low back pain patient is often unsatisfactory because a clear morphological alteration explaining the patient's symptoms can only be found in 10-20% of the cases. The majority of the patients is suffering from non-specific low back pain. However, the high incidence of benign, self-limiting low back pain leads to the risk of overlooking specific causes such as tumor or infection. Similarly, relevant paresis and bladder and bowel dysfunction must be diagnosed in time. Furthermore, the aim of the diagnostic work-up is to diagnose and treat specific causes of back and leg pain (e.g. disc herniation and spinal stenosis) to avoid chronicity. In the majority of the cases, history and clinical examination alone allow to differentiate between specific and non-specific low back pain and may lead to a further diagnostic work-up by imaging studies.

Diagnosis, Differential↗
PubMed1999

[Diagnostic assessment in lumbar back pain. II. Imaging and image-guided infiltrations].

The diagnostic assessment of low back pain should predominantly be based on history and clinical examination rather than on imaging studies. The problem of diagnostic imaging in low back pain is related to the high rate of asymptomatic morphological alterations in the lumbar spine. The diagnosis should therefore not be guided by findings in imaging. The imaging studies (standard radiographs and MRI) should verify the clinically suspected diagnosis and further lead to imaging guided injection studies (e.g. nerve root block, facet joint block, sacro-iliac joint block, provocative discography) to differentiate between symptomatic and asymptomatic morphological alterations. With longlasting local anaesthetics and steroids it is possible to achieve a diagnostic as well as a therapeutic effect.

Diagnosis, Differential↗
PubMed1999

Immunohistochemical analysis of type-X-collagen expression in osteoarthritis of the hip joint.

Conflicting data have been reported on the spatial distribution of type X-collagen expression in osteoarthritis, and no concise data exist on a possible correlation between type X-collagen expression and clinical and radiological alterations. Well defined clinical and radiological data were compared with histopathological and immunohistochemical findings to investigate the expression of type-X collagen in osteoarthritis of the hip joint. Femoral heads were obtained in toto from 11 patients undergoing routine hip arthroplasty for femoral neck fractures (n = 3) or osteoarthritis (n = 8) and from 13 patients (age: 12 days to 69 years) without any evidence of hip-joint pathology. Whole coronal sections from the femoral head were decalcified for routine histology and immunohistochemical analysis with use of type-specific monoclonal antibodies to type-X collagen. Our results demonstrate that type-X collagen is consistently found in osteoarthritic cartilage and is absent from normal adult cartilage (including the region of calcified cartilage). Except for the occurrence of type-X collagen in the middle zone of articular cartilage in advanced stages of osteoarthritis, there is no specific change in the staining pattern or intensity for the collagen during osteoarthritis, particularly when the staining is related to clinical and radiological parameters. Hardly more than 20% of the extracellular matrix stained for type-X collagen; therefore, we suggest that, in most cases, this type of collagen may not play a direct biomechanical role in the weakening of osteoarthritic cartilage but rather may contribute indirectly to a disturbance of the disc biomechanics by altering matrix-molecule interaction. However, expression of type-X collagen may indicate a change in chondrocyte phenotype that consistently coincides with the formation of chondrocyte clusters, one of the first alterations in osteoarthritis visible on histologic examination.

Adolescent↗
PubMed1999

MR imaging and CT in osteoarthritis of the lumbar facet joints.

OBJECTIVE: To test the agreement between MR imaging and CT in the assessment of osteoarthritis of the lumbar facet joints, and thus to provide data about the need for an additional CT scan in the presence of an MR examination. DESIGN AND PATIENTS: Using a four-point scale, two musculoskeletal radiologists independently graded the severity of osteoarthritis of 308 lumbar facet joints on axial T2-weighted and on sagittal T1- and T2-weighted turbo-spin-echo images and separately on the corresponding axial CT scans. Kappa statistics and percentage agreement were calculated. RESULTS: The weighted kappa coefficients for MR imaging versus CT were 0.61 and 0.49 for readers 1 and 2, respectively. The weighted kappa coefficients for interobserver agreement were 0.41 for MR imaging and 0.60 for CT, respectively. There was agreement within one grade between MR and CT images in 95% of cases for reader 1, and in 97% of cases for reader 2. CONCLUSION: With regard to osteoarthritis of the lumbar facet joints there is moderate to good agreement between MR imaging and CT. When differences of one grade are disregarded agreement is even excellent. Therefore, in the presence of an MR examination CT is not required for the assessment of facet joint degeneration.

Adult↗