Vertebral fractures cascade: potential causes and risk factors.

We performed a study to identify potential causes and risk factors of vertebral fracture cascade. Vertebral fracture cascade is a severe clinical event in patients with bone fragility. Only half of patients have an identified cause of secondary osteoporosis. INTRODUCTION: Vertebral fracture (VF) is the most common osteoporotic fracture, and a strong risk factor of subsequent VFs leading to VF cascade (VFC). We prompted a study to identify potential causes and risk factors of VFC. METHODS: VFC observations were collected retrospectively between January 2016 and April 2017. VFC was defined as an occurrence of at least three VFs within 1 year. RESULTS: We included in 10 centers a total of 113 patients with VFC (79.6% of women, median age 73, median number of VFs in the cascade, 5). We observed 40.5% and 30.9% of patients with previous major fractures and a previous VF, respectively, and 68.6% with densitometric osteoporosis; 18.9% of patients were currently receiving oral glucocorticoids and 37.1% in the past. VFC was attributed by the physician to postmenopausal osteoporosis in 54% of patients. A secondary osteoporosis associated with the VFC was diagnosed in 52 patients: glucocorticoid-induced osteoporosis (25.7%), non-malignant hemopathies (6.2%), alcoholism (4.4%), use of aromatase inhibitors (3.6%), primary hyperparathyroidism (2.7%), hypercorticism (2.7%), anorexia nervosa (2.7%), and pregnancy and lactation-associated osteoporosis (1.8%). A total of 11.8% of cases were reported following a vertebroplasty procedure. A total of 31.5% patients previously received an anti-osteoporotic treatment. In six patients, VFC occurred early after discontinuation of an anti-osteoporotic treatment, in the year after the last dose effect was depleted: five after denosumab and one after odanacatib. CONCLUSION: The results of this retrospective study showed that only half of VFC occurred in patients with a secondary cause of osteoporosis. Prospective studies are needed to further explore the determinants of this severe complication of osteoporosis.

Microbiological diagnosis of vertebral osteomyelitis: relevance of second percutaneous biopsy following initial negative biopsy and limited yield of post-biopsy blood cultures.

The purpose of this investigation was to evaluate the microbiological diagnosis yield of post-biopsy blood cultures (PBBCs) and second percutaneous needle biopsy (PNB) following an initial negative biopsy in vertebral osteomyelitis (VO) without bacteremia. A retrospective multicenter study was performed. Patients with VO, pre-biopsy negative blood culture(s), ≥1 PNB, and ≥1 PBBC (0-4 h) were included. One hundred and sixty-nine PNBs (136 first and 33 following initial negative biopsy) were performed for 136 patients (median age = 58 years, sex ratio M/F = 1.9). First and second PNBs had a similar yield: 43.4 % (59/136) versus 39.4 % (13/33), respectively. Only two PBBCs (1.1 %) led to a microbiological diagnosis. The strategy with positive first PNB and second PNB following an initial negative result led to microbiological diagnosis in 79.6 % (74/93) of cases versus 44.1 % (60/136) for the strategy with only one biopsy. In the multivariate analysis, young age (odds ratio, OR [95 % confidence interval (CI)] = 0.98 [0.97; 0.99] per 1 year increase, p = 0.02) and >1 sample (OR = 2.4 ([1.3; 4.4], p = 0.007)) were independently associated with positive PNB. To optimize microbiological diagnosis in vertebral osteomyelitis, performing a second PNB (after an initial negative biopsy) could lead to a microbiological diagnosis in nearly 80 % of patients. PBBC appears to be limited in microbiological diagnosis.

Long-term effects of infliximab on bone and cartilage turnover markers in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is associated with systemic bone loss, subchondral bone erosion and cartilage degradation under the control of pro-inflammatory cytokines, including tumour necrosis factor alpha (TNFalpha). Therefore, we tested the hypothesis that administration of infliximab, an anti-TNFalpha drug in the treatment of RA, would modulate systemic and local bone resorption and reduce cartilage degradation. METHODS: We performed a prospective study of a multicentric cohort of 48 women, mean (SD) age 54.2 (12.1) years old, with severe RA for 11.4 (7.8) years, who started infliximab after failure of other disease-modifying antirheumatic drugs. At baseline and 6, 22 and 54 weeks after initiating Infliximab therapy we measured the following biochemical markers: pro-collagen serum type I N-terminal propeptide (PINP), a marker of bone formation; serum C-terminal cross-linked telopeptide of type I collagen (CTX-I), a marker of cathepsin K-mediated bone collagen degradation believed to reflect systemic bone resorption; serum C-terminal cross-linked telopeptide of type I collagen (ICTP), an index of matrix metalloprotease (MMP) mediated type I collagen degradation reflecting preferential joint metabolism; and urinary CTX-II a biochemical markers of cartilage degradation. Total hip and lumbar spine bone mineral density (BMD) was assessed at baseline, and after 6 and 12 months by dual-energy x-ray absorptiometry (DXA). No patient received bisphosphonates while 77% were under oral glucocorticoids. RESULTS: BMD remained stable over 1 year. Serum CTX-I levels rapidly decreased by 19% and 28% at week 6 and week 22, respectively (analysis of variance (ANOVA) p = 0.032) values returning to pre-treatment level at week 54. By contrast, ICTP levels progressively declined with a maximal 25% decrease at week 54 (ANOVA p = 0.028). By contrast, PINP levels remained stable over time, which led to a 30 to 40% improvement in bone remodelling balance, as assessed by the ratios PINP/CTX and PINP/ICTP (p<0.05). There was no significant change of urinary CTX-II in the whole population, but a slight decrease (ANOVA p = 0.041) in those with pre-treatment levels above the upper limit of normal range. CONCLUSIONS: In summary, the improvement in the formation/resorption marker ratio suggests beneficial systemic and local bone effects of infliximab in patients with RA.

[Effects of smoking on the thyroid gland, digestive system, kidney and bone]. / Effets du tabagisme sur la thyroïde, le tube digestif, le rein et l'os.

INTRODUCTION: In addition to being a major cardiovascular risk factor, smoking promotes or worsens thyroid, digestive, renal and bone diseases. BACKGROUND: Smoking is positively associated with hyperthyroidism. It is associated with Graves' disease and it especially increases the risk of the development of severe exophthalmos. In contrast, smoking might exert a protective action for thyroid carcinoma. Smoking increases the severity of hepatic lesions in patients with chronic hepatitis C. Smoking accelerates the progression of primary biliary cirrhosis and increases the risk of hepatocellular carcinoma. Smoking increases risk of both hyperplastic and adenomatous polyps. While Crohn's disease is associated with smoking, ulcerative colitis is largely a disease of non smokers. Smoking increases risk of development of both renal cell carcinoma and chronic nephropathies, particularly in types 1 and 2 diabetes. Smoking is a risk factor for decreased bone density and is associated with a significantly increased risk of fracture. Smoking is related to the development of rheumatoid arthritis and may adversely influence its severity. CONCLUSIONS: Smoking might be considered a risk factor for the development of several thyroid, digestive, renal and bone diseases. Consequently, smoking prevention and cessation programs must be strongly encouraged among the patients concerned.

Medical management of failed back surgery syndrome in Europe: evaluation modalities and treatment proposals.

Failed back surgery syndrome (FBSS) is defined as persistent pain more than 3 months after any form of spinal surgery. Due to its multifactorial origin, FBSS is often difficult to treat. In this context of failed back surgery, a very thorough assessment must be conducted concerning the site and characteristics of the pain (nociceptive or neuropathic), its mode of onset (presence or absence of pain-free intervals), and its impact on the patient's work and social life. Physical examination must exclude a non-spinal cause for the pain. MRI is the imaging modality of choice in this disease, but is often difficult to interpret, as MR signals are modified for 6 months after the operation. Scar tissue, which can be distinguished from recurrent disc hernia by its gadolinium enhancement, is present even in asymptomatic patients. After having eliminated infection and sacroiliac or posterior facet joint disease, the main aetiologies investigated are foraminal stenosis, degenerative disc disease, recurrent disc hernia, and non-union of spinal fusion; sometimes patients only experience persistent neuropathic pain. The treatment of failed back surgery syndrome with a predominant neuropathic component is based on the use of analgesics, especially antiepileptics, antidepressants or transcutaneous electrical stimulation. Epidural spinal infiltration should be considered as second-line treatment in view of the risk of serious neurological complications. Management must be based on a global, multidisciplinary approach with identification of any cognitive or behavioural disorders in combination with an appropriate functional rehabilitation programme.

Multicolumn spinal cord stimulation for significant low back pain in failed back surgery syndrome: design of a national, multicentre, randomized, controlled health economics trial (ESTIMET Study).

BACKGROUND: Many studies have demonstrated the efficacy of spinal cord stimulation (SCS) for chronic neuropathic radicular pain over recent decades, but despite global favourable outcomes in failed back surgery syndrome (FBSS) with leg pain, the back pain component remains poorly controlled by neurostimulation. Technological and scientific progress has led to the development of new SCS leads, comprising a multicolumn design and a greater number of contacts. The efficacy of multicolumn SCS lead configurations for the treatment of the back pain component of FBSS has recently been suggested by pilot studies. However, a randomized controlled trial must be conducted to confirm the efficacy of new generation multicolumn SCS. Évaluation médico-économique de la STImulation MEdullaire mulTi-colonnes (ESTIMET) is a multicentre, randomized study designed to compare the clinical efficacy and health economics aspects of mono- vs. multicolumn SCS lead programming in FBSS patients with radicular pain and significant back pain. MATERIALS AND METHODS: FBSS patients with a radicular pain VAS score≥50mm, associated with a significant back pain component were recruited in 14 centres in France and implanted with multicolumn SCS. Before the lead implantation procedure, they were 1:1 randomized to monocolumn SCS (group 1) or multicolumn SCS (group 2). Programming was performed using only one column for group 1 and full use of the 3 columns for group 2. Outcome assessment was performed at baseline (pre-implantation), and 1, 3, 6 and 12months post-implantation. The primary outcome measure was a reduction of the severity of low back pain (bVAS reduction≥50%) at the 6-month visit. Additional outcome measures were changes in global pain, leg pain, paraesthesia coverage mapping, functional capacities, quality of life, neuropsychological aspects, patient satisfaction and healthcare resource consumption. TRIAL STATUS: Trial recruitment started in May 2012. As of September 2013, all 14 study centres have been initiated and 112/115 patients have been enrolled. Preliminary results are expected to be published in 2015. TRIAL REGISTRATION: Clinical trial registration information-URL: www.clinicaltrials.gov. Unique identifier NCT01628237.

The effects of fibroblast growth factor-2 on human neonatal calvaria osteoblastic cells are differentiation stage specific.

Fibroblast growth factors (FGFs) appear to play an important role in human cranial osteogenesis. We therefore investigated the effects of recombinant human FGF-2 (rhFGF-2) on human calvaria (HC) osteoblastic cells. Immunocytochemical analysis showed that confluent HC cells express both FGF receptors -1 and -2. In short-term culture, rhFGF-2 (0.1-100 ng/ml, 2-5 days) increased HC cell growth and decreased alkaline phosphatase (ALP) activity and type I collagen (ColI) synthesis, as evaluated by P1CP levels. When HC cells were induced to differentiate in long-term culture in the presence of 50 microg/ml ascorbic acid and 3 mM phosphate, HC cells initially proliferated, then ALP activity and ColI synthesis decreased and calcium content in the extracellular matrix increased. Continuous treatment with rhFGF-2 (50 ng/ml) for 1-28 days, or a transient rhFGF-2 treatment for 1-7 days, slightly increased DNA synthesis at 7 days, whereas a late treatment for 8-28 days had no effect on cell growth. The continuous and transient treatments with rhFGF-2 decreased ALP activity, ColI synthesis, and matrix mineralization. This was associated with a transient fall in osteocalcin (OC) production at 7 days. In contrast, the late rhFGF-2 treatment for 8-28 days only slightly inhibited ALP activity and increased matrix mineralization. In addition, both continuous and late treatments with rhFGF-2 increased OC production in more mature cells at 3-4 weeks of culture. We also found that the early and late treatments with rhFGF-2 had opposite effects on transforming growth factor beta2 production in proliferating cells and more mature cells. The results show that rhFGF-2 slightly stimulates cell growth and reduces the expression of osteoblast markers in less mature cells, whereas it induces OC production and matrix mineralization in more mature cells, indicating that the effects of FGF-2 are differentiation stage specific and that FGF-2 may modulate HC osteogenesis by acting at distinct stages of cell maturation.

Regulation of human cranial osteoblast phenotype by FGF-2, FGFR-2 and BMP-2 signaling.

The formation of cranial bone requires the differentiation of osteoblasts from undifferentiated mesenchymal cells. The balance between osteoblast recruitment, proliferation, differentiation and apoptosis in sutures between cranial bones is essential for calvarial bone formation. The mechanisms that control human osteoblasts during normal calvarial bone formation and premature suture ossification (craniosynostosis) begin to be understood. Our studies of the human calvaria osteoblast phenotype and calvarial bone formation showed that premature fusion of the sutures in non-syndromic and syndromic (Apert syndrome) craniosynostoses results from precocious osteoblast differentiation. We showed that Fibroblast Growth Factor-2 (FGF-2), FGF receptor-2 (FGFR-2) and Bone Morphogenetic Protein-2 (BMP-2), three essential factors involved in skeletal development, regulate the proliferation, differentiation and apoptosis in human calvaria osteoblasts. Mechanisms that induce the differentiated osteoblast phenotype have also been identified in human calvaria osteoblasts. We demonstrated the implication of molecules (N-cadherin, Il-1) and signaling pathways (src, PKC) by which these local factors modulate human calvaria osteoblast differentiation and apoptosis. The identification of these essential signaling molecules provides new insights into the pathways controlling the differentiated osteoblast phenotype, and leads to a more comprehensive view in the mechanisms that control normal and premature cranial ossification in humans.

New factors controlling bone remodeling.

Two factors of crucial importance in bone cell differentiation were discovered within the last two years. One is the transcription factor Osf2/Cbfa1, which allows mesenchymal stem cells to differentiate into osteoblasts. Soluble factors, including bone morphogenetic proteins (BMPs), leptin, and TGF-beta, can modulate differentiation of mesenchymal stem cells to osteoblasts or to other cell types such as chondrocytes or adipocytes. The other recent discovery is osteoclast differentiating factor (ODF), which is specific for and indispensable to osteoclast differentiation. ODF belongs to the TNF family. Its soluble receptor, osteoprotegerin, prevents it from binding to osteoclasts, thus inhibiting its activity. A role of lymphocytes in bone remodeling has long been suspected, and it has now been shown that ODF is produced by activated T lymphocytes, which may therefore be implicated in bone loss accompanying inflammation. Finally, recent evidence supports a role for B lymphocytes in bone loss secondary to estrogen deprivation. In conclusion, these recent data may have important applications. Osteoprotegerin is a potent antiosteoclast agent that may prove useful in the treatment of bone disorders. Osf2/Cbfa1 and ODF are major targets in the treatment of osteoporosis.

Bone density, parathyroid hormone, calcium and vitamin D nutritional status of institutionalized elderly subjects.

INTRODUCTION: Osteoporosis is characterized by a decrease in bone mass and a change in bone microarchitecture. This causes skeletal fragility and may result in fractures. Fractures of the femur neck (FM) are frequent and have major consequences in terms of morbidity and mortality in elderly subjects. We carried out a cross-sectional study to evaluate bone and nutritional status in an elderly population from a same geriatrics department. AIMS OF THE STUDY: We aimed to screen for nutritional deficiencies and to measure bone mineral density (BMD) in the femur neck by dual-energy X-ray absorptiometry (DEXA). RESULTS: The study included 64 white Caucasian subjects, 44 of whom were women. The mean age of the subjects was 80.6 +/- 7.1 years. The mean time since the menopause was 31.45 +/- 7.8 years and 31 subjects presented previous fractures, 12 of which concerned the FM. Mean body mass index (BMI) was 25.8 +/- 4.4 and mean calcium intake was 670 +/- 258.3 mg/d. Mean PTH level was 48.5 +/- 30.34. Thirty-five subjects presented vitamin D deficiencies (mean concentration 8.56 +/- 5.2 microg/L), and 11 of these patients had associated secondary hyperparathyroidism. Fifty-four subjects had osteoporosis (T score <-2.5 standard deviation). Mean bone mineral density (BMD) was 0.596 +/- 0.157 g/cm2 for the femur neck (T score = -3.15 +/- 1.39 standard deviation) and 0.501 +/- 0.169 g/cm2 for the trochanter (T score = - 2.55 +/- 1.68 standard deviation). CONCLUSIONS: Vitamin D deficiency and low calcium intake were observed in a large number of elderly subjects. The patients with the lowest BMD values had secondary hyperparathyroidism.

Time-frequency analysis of heart murmurs. Part I: Parametric modelling and numerical simulations.

The object of this study is to compare the performance of two new bilinear time-frequency representation techniques with the spectrogram to characterise the behaviour of heart murmurs produced by bioprosthetic heart valves implanted in the mitral or aortic position. The murmurs are those of mitral stenosis, mitral regurgitation, aortic stenosis, aortic regurgitation, a diastolic musical murmur and a systolic musical murmur. In the first part of the study, the general characteristics of the amplitude and the spectral content of these murmurs are determined by visual observation of the spectrogram of phonocardiograms obtained from several patients with known valvular pathology complemented with a literature review. A parametric model is then generated for each murmur signal. Stenotic and regurgitant murmurs are modelled as the sequential output of a bank of low-pass filters excited by a white noise input signal. The basic parameters of each filter are selected to simulate, as a function of time, the basic characteristics of random heart murmurs. Musical murmurs are modelled as a frequency-modulated deterministic sinusoid of constant amplitude. Numerical simulations of these random and musical heart murmurs are then generated and will be used in Part II to determine the best of three time-frequency representation techniques for analysing heart murmur signals.

Time-frequency analysis of heart murmurs. Part II: Optimisation of time-frequency representations and performance evaluation.

The basic parameters of the spectrogram, the Choi-Williams, and the Bessel distributions are adjusted to provide the best time-frequency representations (TFRs) of the simulated murmur signals of mitral stenosis, mitral regurgitation, aortic stenosis, aortic regurgitation, and of two musical murmurs. The initial adjustment of the parameters of each TFR technique is performed by computing and minimising the relative averaged absolute error between the frequency contours at -3 dB and -10 dB of each TFR of the simulated murmurs and those of the theoretical distribution of the same signals. The results show that the spectrogram generally provides very good to excellent performance in representing the TFRs of stenotic and regurgitant murmurs. Improvements provided by the Choi-Williams and the Bessel distributions are minor but not systematic for the two signal-to-noise ratios tested (0 and 30 dB) and for the two frequency contours estimated. The Bessel and the Choi-Williams distributions provide the best performance for the musical murmurs. The study shows that although a single technique cannot be optimal for all six murmurs, the spectrogram using a Hamming window of 30 ms is an acceptable compromise to detect the six simulated heart murmurs.

[Are the anatomopathological classifications of primary Gougerot-Sjögren syndrome correlated with each-other and with clinical symptoms?]. / Les classifications anatomopathologiques du syndrome de Gougerot-Sjögren primitif sont-elles corrélées entre elles et à la clinique?

Seventy-two cases of primary Sjögren's syndrome, according to the European classification criteria, were studied looking for a correlation between anatomic criteria and clinico-biological signs in this disease. Labial salivary gland biopsy was performed in all patients and anatomic criteria were evaluated according to both Chisholm and Chomette scales. Work-up included recording of functional and clinical signs. Our study shows no clinico-histological correlation in Sjögren's syndrome. Moreover, we did not find any correlation between the two histological scales. We think, therefore, that labial salivary gland biopsy appears to be an important step in Sjögren's syndrome diagnosis according to European criteria. However, it does not present any benefit in patient treatment.

[Unsatisfactory results of intradiscal injection of triamcinolone hexacetonide in the treatment of sciatica caused by intervertebral disk herniation]. / Mauvais résultats de l'injection intradiscale de l'hexacétonide de triamcinolone dans le traitement des sciatiques par hernie discale.

Sciatica caused by intervertebral disc herniation can be treated with intradiscal injection of chymopapain. A search for a cheaper and less allergizing product led to triamcinolone hexacetonide, this procedure being known as "nucleorthesis". The first results at 6 months were encouraging. In 3 centres where triamcinolone hexacetonide was tested with a more than 2 years' follow-up 92 patients could be evaluated. The results obtained were considered satisfactory in 34 patients (36.9 percent), but they were poor in 19 patients (20.6 percent), and 39 patients (42 percent) had to be operated upon within 2 years. Return to surgery took place within the 6 months following nucleorthesis in 18 patients (19.56 percent) and beyond this period in 17 patients (22.8 percent) with degradation of the results. Moreover, calcifications were found in 19 out of 38 patients; they were of varying size, sometimes detected only at computerized tomography, and some of them appeared to produce symptoms. All considered, the failure rates, the number of patients who required surgery and the occurrence of large and sometimes symptomatic calcifications make triamcinolone nucleorthesis unacceptable compared with the recognized percentages of success with papain nucleolysis and surgical operations. For these reasons, we consider that this treatment should be abandoned.

[Schwannoma of the obturator nerve with urologic manifestations: report of a case]. / Schwannome du nerf obturateur à manifestations urologiques: à propos d'une observation.

Peripheral nerve tumors, which are called schwannomas because they arise from nerve sheath Schwann cells, are rare tumors than can develop at any site in the body but involve the limbs in over 50% of cases. Only 13% of schwannomas arise in the trunk; about 3% of schwannomas are retroperitoneal, and about 4% of retroperitoneal tumors are schwannomas. Pelvic schwannomas are equally uncommon and can develop in a broad range of structures. The most common presenting manifestation is a very large space-occupying lesion responsible for compression of neighboring organs. Excision of the tumor is often extremely difficult or impossible. Although obturator nerve schwannomas are exceedingly rare, their paravesical location is suggestive of he diagnosis. Computed tomography and magnetic resonance imaging are the most useful investigations, although they cannot determine the exact nature of the tumor. During surgery, every effort should be made to preserve the integrity of the nerve, although this is not always possible; obturator nerve injury does not seem associated with severe impairments.

[Schwannoma and the urinary tract. Concerning a tumor of the obdurator nerve]. / Schwannome et appareil urinaire. A propos d'une tumeur du nerf obturateur.

Peripheral nerve tumours, called schwannomas, because they are derived from cells of the Schwann sheath, are rare tumours that can involve any part of the body, but are essentially located on the limbs, which represent more than 50% of cases. Schwannomas of the trunk and especially pelvic schwannomas are even rarer. A tumour arising from the obturator nerve is exceptional, but its paravesical location can facilitate the diagnosis, as in this case. The complementary investigations most frequently performed are CT and MRI, although they are unable to define the exact nature of the tumour. Surgery must try to preserve continuity of the nerve, but that is not always possible and does not appear to have any major consequences in this site.

[Lyme disease]. / La maladie de Lyme.

Lyme disease is an infectious disease due to Borrelia burgdorferi, which is transmitted by a tick bite. Bearing ticks belong to the "Ixodes" type. Germ reservoirs include rodents, birds, deers... The disease onset usually takes place in summer or in autumn. Its early stage is characterized by erythema chronicum migrans. The secondary stage, initiated by a virus-like syndrome indicating the hematogenous and lymphatic dissemination may include neurologic symptoms and signs--the most frequent ones in France and Europe (meningoradiculitis, meningitis, palsy of one or several cranial nerves), cardiac symptoms (conduction dysfunction), a relapsing oligoarthritis, and sometimes ocular signs. In some cases, joint and/or nervous system symptoms may become chronic: it's the tertiary (late) stage, which may include, too, acrodermatitis chronica atrophicans. Any of these symptoms may initiate the disease or be its only manifestation. When erythema chronicum migrans is missing, diagnosis lays upon serology which may turn positive only lately, or remain negative; the possibility of false positivity must also be noticed. Antibiotherapy must be initiated as soon as possible; even when started lately, it may prove beneficial. It consists essentially of beta lactamins or doxycyclin. Studies are progressing in view of the elaboration of a vaccine.

[Treatment of Takayasu's disease with low-dose methotrexate. Apropos of a case]. / Traitement de la maladie de Takayasu par le méthotrexate à faible dose. A propos d'un cas.

Persistent evidence of inflammation at the occlusive phase of Takayasu's arteritis is of adverse prognostic significance. Low-dose weekly methotrexate therapy given in combination with a corticosteroid may be effective in such patients. We report a personal case which supports the data obtained by Fauci and coworkers, as well as the conclusions of the other two similar case-reports in the literature.

[Chemonucleolysis of disk herniation with low back pain as the single symptom: 20 cases]. / Chimionucléolyse des hernies discales avec lombalgie pure: vingt cas.

Disk herniation can manifest as isolated low back pain, which is usually intermittent and accompanied with stiffness of the lumbar spine. There is almost general agreement that neither neurosurgical treatment nor chemonucleolysis is appropriate in patients with this clinical pattern. We used chemonucleolysis in 19 patients with recurrent episodes of isolated low back pain and one patient with severe permanent isolated low back pain dating back to a conservatively-treated episode of sciatica. All 20 patients had disk herniation documented by imaging studies. A very good or satisfactory outcome was recorded in ten patients after three months, 11 after six months and 12 in March 1993 after a mean follow-up of 72 months. The treatment was well tolerated, even in those patients who were not improved; a single patient developed an episode of acute low back pain that required surgical treatment. In patients with low back pain and disk herniation, there is currently no means of determining whether a causal relationship links these two abnormalities. Nevertheless, we believe that chemonucleolysis can be proposed in severe forms, provided the patients are apprised of current success rates.