Denosumab use in bone fibrous dysplasia refractory to bisphosphonate: A retrospective multicentric study.

INTRODUCTION: Increased RANKL expression is observed in the bone tissue of fibrous dysplasia of bone/McCune-Albright syndrome (FD/MAS). In one animal model of FD/MAS, the inhibition of RANKL reduced tumor volume. A beneficial effect of denosumab on pain in patients refractory to bisphosphonates has been reported, but without systematic quantification of pain improvement. This work describes the clinical experience of our group on the efficacy on pain of denosumab treatment, along with safety, in FD/MAS patients refractory to bisphosphonates. MATERIALS AND METHODS: We have conducted a retrospective multicenter study in 6 academic rheumatology centers in France. We have collected patients and FD/MAS characteristics, duration of prior exposure to bisphosphonates, denosumab treatment modalities (dosage - administration regimen - number of courses); evolution of pain evaluated by Visual Analogic Scale (VAS). RESULTS: 13 patients were included (10 women and 3 men) 45 years on average, 5 MAS, 4 monostotic and 4 polyostotic forms. The average duration post-diagnosis of FD/MAS was 25 years and the mean duration of prior exposure to bisphosphonates was 4.7 years. Pain could be analyzed in 7 patients, showing a significant improvement from a mean VAS of 7.8 to 2.9 (-4.9 points, p = 0.003). In one patient with fronto-orbital FD/MAS, a 30 % decrease in lesional volume, assessed by MRI, was observed within 6 months of treatment, that was sustained over the following 12 months. Treatment regimens were heterogeneous. No hypercalcemia was observed after treatment cessation and the clinical tolerance was good. DISCUSSION: This study suggests that denosumab reduces pain in patients with DF/MAS refractory to bisphosphonates, and quantifies this improvement for the first time in a multicenter study. In our cohort, no patients who discontinued denosumab developed hypercalcemia and clinical tolerance was overall good. This study also provides encouraging data regarding lesion volume control. Further controlled studies are required to determine the place and modalities of the denosumab treatment of FD/MAS. CONCLUSION: Denosumab significantly decreased pain in FD/MAS refractory to bisphosphonate. This study paves the way for a randomized clinical trial to validate and standardize the prescription of denosumab in FD/MAS.

Hip fracture incidence and social deprivation: results from a French ecological study.

The association between socioeconomic status (SES) and hip fracture (HF) incidence was analyzed in France in 2008. In men and women, a decrease in HF incidence was observed as the social deprivation index increased. This result may be partly due to the protective effect of increasing body weight against HF. INTRODUCTION: Regional variations in hip fracture (HF) incidence exist worldwide. Reasons for these variations remain unknown. As regional variations have also been observed for socioeconomic status, we analyzed the association between socioeconomic deprivation (SED) and HF incidence in France in 2008. METHODS: From the French Hospital National Database, we selected all HF encoded as primary diagnosis in persons aged 30 years and over. The recently published French version of the European Deprivation Index (EDI) was used for SED analysis, and an EDI score was measured for the year 2007 in each French local municipality. The EDI score was categorized in quintiles. Poisson regression was performed to examine the association between HF incidence and EDI adjusted for age and sex. The population attributable fraction (PAF) was measured to calculate the proportion of excess cases of HF associated with social affluence. RESULTS: In 2008, 83,538 HF were reported in France of which 59,143 were included in this study. Among them, 44,401 fractures occurred in women (75%) and 14,742 in men (25%). In both men and women, there was a decrease in the HF incidence with increasing SED index. In Poisson regression, the interaction of age class and sex was significant (p < 0.0001) and the EDI in quintiles was significantly associated with the incidence of HF (p < 0.0001). A higher number of people living in affluent residential areas corresponded to a higher risk of HF. The risk of HF is 2.42 times higher for those living in the most affluent group compared to those living in the most underprivileged group. The value of the PAF was calculated at 27.1%. CONCLUSION: Social disparities in HF incidence exist in France with the most deprived municipalities having the lowest incidence. Prior knowledge demonstrates the strong relationships between body weight and HF risk as well as between body weight and the SED. The link found in our study between EDI and HF incidence as well as regional and temporal variations in HF incidence may be partly due to the protective effect of increased body weight against HF.

Rheumatoid Factor and Disease Activity Are Independent Predictors of Lymphoma in Primary Sjögren's Syndrome.

OBJECTIVE: To define parameters predictive of lymphoma development in patients with primary Sjögren's syndrome (SS). METHODS: A multicenter case-control survey was performed to identify predictors of lymphoma. Cases were patients who developed lymphoma after diagnosis of primary SS and were mainly recruited through the Club Rhumatismes et Inflammation network. For each case, 2 controls (matched for disease duration and age) were randomly selected among patients with primary SS and without lymphoma. Cases and controls were compared using univariate analysis and then using multivariate analysis to identify independent predictors of lymphoma. RESULTS: One hundred one patients with primary SS and lymphoma were included. Eighty-seven patients were women (86.1%), and the mean ± SD age at lymphoma diagnosis was 57.4 ± 12.6 years. The most frequent histologic type was B cell non-Hodgkin's lymphoma (NHL) in 99 of 101 patients, with marginal-zone lymphoma in 76 of the 99 patients (76.8%) including 58 (58.6%) with lymphoma of the mucosa-associated lymphoid tissue type. Lymphomas were most frequently located in the salivary glands (43 patients). A specific treatment was initiated at diagnosis in 87 patients with B cell NHL, and 61 patients (61.6%) achieved complete sustained remission after the first line of treatment. In the multivariate analysis, salivary gland enlargement, the presence of rheumatoid factor (RF), low C4, cryoglobulinemia, lymphopenia, and disease activity according to the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (excluding the lymphoma domain) were found to be predictors of lymphoma. No previous treatment for primary SS was associated with any effect on lymphoma occurrence. CONCLUSION: In addition to previously known factors predictive of lymphoma occurrence, the independent roles of RF and disease activity were demonstrated in this case-control study of primary SS-associated lymphoma. Our findings highlight the roles of chronic antigenic stimulation and disease activity in the development of this severe complication.

Predictive risk factors of serious infections in patients with rheumatoid arthritis treated with abatacept in common practice: results from the Orencia and Rheumatoid Arthritis (ORA) registry.

OBJECTIVES: Little data are available regarding the rate and predicting factors of serious infections in patients with rheumatoid arthritis (RA) treated with abatacept (ABA) in daily practice. We therefore addressed this issue using real-life data from the Orencia and Rheumatoid Arthritis (ORA) registry. METHODS: ORA is an independent 5-year prospective registry promoted by the French Society of Rheumatology that includes patients with RA treated with ABA. At baseline, 3 months, 6 months and every 6 months or at disease relapse, during 5 years, standardised information is prospectively collected by trained clinical nurses. A serious infection was defined as an infection occurring during treatment with ABA or during the 3 months following withdrawal of ABA without any initiation of a new biologic and requiring hospitalisation and/or intravenous antibiotics and/or resulting in death. RESULTS: Baseline characteristics and comorbidities: among the 976 patients included with a follow-up of at least 3 months (total follow-up of 1903 patient-years), 78 serious infections occurred in 69 patients (4.1/100 patient-years). Predicting factors of serious infections: on univariate analysis, an older age, history of previous serious or recurrent infections, diabetes and a lower number of previous anti-tumour necrosis factor were associated with a higher risk of serious infections. On multivariate analysis, only age (HR per 10-year increase 1.44, 95% CI 1.17 to 1.76, p=0.001) and history of previous serious or recurrent infections (HR 1.94, 95% CI 1.18 to 3.20, p=0.009) were significantly associated with a higher risk of serious infections. CONCLUSIONS: In common practice, patients treated with ABA had more comorbidities than in clinical trials and serious infections were slightly more frequently observed. In the ORA registry, predictive risk factors of serious infections include age and history of serious infections.

Beneficial effects of vitamin D on falls and fractures: is cognition rather than bone or muscle behind these benefits?

The beneficial effect of vitamin D on bone tissue has long been attributed mainly to its positive effect on the intestinal absorption of calcium and on bone mineralization, which increases the bone mineral density (BMD) and thus decreases the risk of fracture. Recently, numerous extra osseous effects of vitamin D have been described, amongst them a positive effect on neuromuscular and cognitive functions. Several lines of evidence suggest that the beneficial effects of vitamin D on fall and fracture risk can be explained more by its action on the neuromuscular and cognitive functions than by its direct effect on bone metabolism. In this review, we first report on the relationships between vitamin D and osteoporotic fracture risk. Then, we present the data from the literature regarding the effects of vitamin D on risk factors such as fall risk and reduction in BMD, physical performance, and cognitive performance. Specific emphasis is put on the latter because there is evidence of a relationship between low concentration of serum 25-hydroxyvitamin D (the primary indicator of vitamin D status) and low cognitive abilities which have been shown to be a risk factor for falling. It can be further suggested that high risk of fracture in cognitively impaired adults could be explained by lower protective reaction when falling, which would result, for instance, from a lack of planning and foresight of the fall. Future studies are nonetheless needed to elucidate the associations between vitamin D and different risk factors, in particular the link between vitamin D and various cognitive functions.

Coracoacromial ligament section under ultrasonographic control: a cadaveric study on 20 cases.

INTRODUCTION: The coracoacromial ligament is a complex anatomical structure involved in the development of subacromial impingement; treatment is founded on sectioning the ligament, with or without associated arthroscopic acromioplasty and debridement. HYPOTHESIS: Complete coracoacromial ligament section can be performed under ultrasound, without lesion to surrounding structures. MATERIALS AND METHODS: The coracoacromial ligament was sectioned on the coracoid side, under ultrasound navigation, in 10 cadavers donated to science: i.e. 20 shoulders. After ultrasound location of the shoulder structures, sectioning was performed with a skin incision at the level of the deltopectoral sulcus. Secondary surgical control checked conservation of the acromial branch of the thoracoacromial artery, and the quality of the procedure. RESULTS: Mean surgery duration was 18.5 minutes (±5 min). Seventeen sections were complete (85%). Artery location was hampered by the impossibility of using Doppler on these cadavers, yet even so there were only 2 vascular lesions. There were no accidental rotator cuff or cartilaginous lesions. CONCLUSION: This relatively non-invasive technique is quick and less heavy than open surgery, opening up new treatment perspectives. It could be indicated in coracoid and subacromial impingement before opting for surgery, or as a complement to surgery. It does, however, involve a learning curve and requires solid ultrasound skills.

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.

Positivity for anti-cyclic citrullinated peptide is associated with a better response to abatacept: data from the 'Orencia and Rheumatoid Arthritis' registry.

OBJECTIVES: Very limited data are available regarding the efficacy of abatacept (ABA) in real life. The aims of this study were to determine the efficacy of ABA in rheumatoid arthritis and predicting factors of efficacy in common practice. METHODS: The Orencia and Rheumatoid Arthritis" (ORA) prospective registry, promoted by the French Society of Rheumatology, has included 1003 patients with RA. RESULTS: 773 patients had already fulfilled the 6-month follow-up visit. Only 21.3% of patients would have fulfilled inclusion criteria used in pivotal controlled trials. The European League Against Rheumatism (EULAR) response, was observed in 330 (59.1%) of the 558 assessed patients (good response: 20.4%, moderate response: 38.7%) and was similar in patients who did and in patients who did not fulfill inclusion criteria of controlled trials. Among EULAR responders, initial 28-joint disease activity score (5.4 (4.7-6.5) in responders vs 4.9 (4.0-6.0) in non responders, p< 0.0001), the proportion of rheumatoid factor (75.6% vs 66.7%, p= 0.03) and the proportion of anti-cyclic citrullinated peptide antibody (anti-CCP)-positivity (75.9% vs 62.2%, p= 0.001) were significantly higher. In multivariate analysis adjusted on initial 28-joint disease activity score and CRP, anti-CCP positivity was associated with EULAR response (OR=1.9;95% CI=1.2 to 2.9, p=0.007), but not rheumatoid factor (OR=1.0;95% CI=0.6 to 1.6, p=0.9). Anti-CCP positivity was also significantly associated with a higher ABA retention rate at 6 months. CONCLUSIONS: Real life efficacy of ABA in the ORA registry was similar as that reported in clinical trials. Anti-CCP positivity was associated with a better response to ABA, independently from disease activity.

Efficacy of rituximab in primary Sjogren's syndrome with peripheral nervous system involvement: results from the AIR registry.

OBJECTIVE: To evaluate rituximab (RTX) in primary Sjögren's syndrome (pSS) with peripheral nervous system (PNS) involvement. METHODS: Patients with pSS and PNS involvement who were included in the French AIR registry were analysed. RESULTS: 17 patients (age 60 years (44-78 years); 14 were female) were analysed. Neurological improvement was noted in 11 patients (65%) at 3 months. Rankin scale decreased from 3 (1-5) to 2 (1-5), 2 (1-5) and 2 (1-6) after 3, 6 and 9 months (p=0.02). European Sjögren's Syndrome Disease Activity Index decreased from 18 (10-44) to 11 (5-20), 11 (5-29) and 12 (5-30) after 3, 6 and 9 months (p<0.05). RTX was effective in neurological involvement in 9/10 patients with vasculitis or cryoglobulinaemia (90%) (group 1) at 3 months and in 2/7 cases (29%) without cryoglobulinaemia and vasculitis (p=0.03). Rankin and European Sjögren's Syndrome Disease Activity Index scales decreased significantly in group 1. CONCLUSION: RTX seems effective in cryoglobulinaemia or vasculitis-related PNS involvement in pSS.

A crystallinity study of dental tissues and tartar by infrared spectroscopy.

In this paper we report a study of an important property of biomineralized phases, crystallinity, on the basis of previous results for synthetic apatite. Crystallinity is not only important for understanding biomineralization, it is also related to the maturation and mechanisms of growth of calcium phosphates in biological surroundings. We studied two kinds of sample, teeth as an example of biomineralized tissues and dental calculi (adhering) as an example of mineralization without participation of biological agents, except possibly bacteria. The investigation focused on study of ν(1)-ν(3) infrared absorption bands of PO(4)(3-) phosphates. We used ATR (attenuated total reflection) analysis to examine human dental tissues and tartar on several samples. The results confirm for the first time previous assumptions about the growth and maturation of dental calculi, i.e., crystallinity progresses from regions of high crystallinity to regions of lower crystallinity, and, in addition, its quantification with spatial resolution in the sample. A gradual pattern was observed in dental calculus. Another result from this study was that cementum and dentine had similar crystallinity, despite their different biological and mechanical functions.

[Can tumor necrosis factor inhibitors induce sclero-uveitis?]. / Les anti-Tnf peuvent-ils induire des scléro-uvéites ?

We report three cases of female patients who presented a first episode of unilateral scleritis or acute anterior uveitis while they were treated for 12-16 months by TNF inhibitor: etanercept (Enbrel((R))) 25mg twice weekly for rheumatologic diseases (rheumatoid arthritis or ankylosing spondylitis). Ocular inflammation was resistant to the usual treatment. Some cases of scleritis and uveitis are known to be drug-induced. TNF inhibitors seem to be part of them. Ocular inflammation is usually the first episode. It appears generally in the first year of the treatment by TNF inhibitors and resists to usual treatment. The general disease is usually well stabilized. In our cases, inflammation decreased only when the etanercept was discontinued.

Inverse relationship between vertebral fractures and spine osteoarthritis in postmenopausal women with osteoporosis.

BACKGROUND: Although the coexistence of osteoarthritis and osteoporosis is considered as uncommon, it has been suggested that, in postmenopausal women, disc space narrowing increases the risk of vertebral fracture. The aim of this study was to check this hypothesis in postmenopausal women with osteoporosis. OBJECTIVE: We analysed the relationship between vertebral fractures and spine osteoarthritis in 410 postmenopausal women with osteoporosis: in this population both disc space narrowing and osteophytes are inversely related to vertebral fractures. PATIENTS AND METHODS: This study is based on baseline data collected in a multicentre, prospective and 6-month longitudinal observational study. 410 postmenopausal women (74+/-5 years) were enrolled who had consulted for back pain, and had osteoporosis (according to WHO definition). Spine x-rays were performed according to standardised procedures. Vertebral fractures were evaluated from T4 to L4 using the Genant's semiquantitative method; osteoarthritis was evaluated by scoring osteophytes and disc space narrowing at all levels of the thoracic and lumbar spine, and by a qualitative assessment of facet joint arthritis. RESULTS: The prevalence of vertebral fractures was 52.4%. At least one osteophyte, one disc space narrowing and one facet arthritis were present in 90.2, 64.6 and 77.8% of patients respectively. There was an inverse association between vertebral fractures and osteoarthritis: odds ratios adjusted for age and weight (95% CI) were 0.38 (0.17-0.86), p = 0.02 and 0.27 (0.16-0.46), p<10(-4) for the presence of at least one osteophyte, and of at least three disc space narrowings respectively. In a cluster analysis, it was possible to identify a subgroup of patients without any disc space narrowing, and another subgroup with all patients having at least one disc space narrowing; the proportion of patients having more than three vertebral fractures was 25.2 and 15.9% in these two clusters respectively. CONCLUSIONS: Disc space narrowing and osteophytes are associated with a decreased vertebral fracture prevalence in postmenopausal women with osteoporosis.

Anti-tumour necrosis factor treatment in patients with refractory systemic vasculitis associated with rheumatoid arthritis.

OBJECTIVE: To assess anti-tumour necrosis factor (anti-TNF) agents in patients with refractory systemic rheumatoid vasculitis (SRV). METHODS: 1200 rheumatologists and internists were asked to provide medical files for patients with anti-TNF agents given as a second-line treatment for active SRV refractory to cyclophosphamide and glucocorticoids. RESULTS: We identified nine cases in which anti-TNF drugs were given for active SRV, despite previous treatment with a mean cumulative dose of 8.4 g of cyclophosphamide in association with high-dose glucocorticoids. The mean prednisone dose before anti-TNF therapy was 29.6 mg/day. After 6 months, six patients were in remission (complete in five, partial in one). The treatment failed in one patient and two patients stopped taking the anti-TNF treatment due to side-effects. Mean prednisone dose was reduced to 11.2 mg/day. Severe infection occurred in three patients. Relapses were observed in two patients. Remission was re-established by reintroducing anti-TNF therapy in one case and increasing the dose in the other. CONCLUSIONS: This study provides evidence of efficacy of anti-TNF therapy in adjunct to glucocorticoids for treating active refractory SRV. Remission was achieved in two-thirds of patients, with a significant decrease in prednisone dose, although there was a high rate of infection in these severely ill patients.

Prevalence of vertebral fractures in French women older than 75 years from the EPIDOS study.

The aim of this study was to ascertain the prevalence and severity of vertebral fractures in French elderly women. We used spinal radiographs collected during the baseline examination of the Epidémiologie de l'Ostéoporose (EPIDOS) study, a multicentric prospective study of risk factors for hip fracture. A total of 7598 ambulatory women volunteers were recruited in the EPIDOS cohort using large population-based listings such as voter-registration lists. A subsample of 770 participants were selected for spinal radiographs using a systematic selection procedure. Anteroposterior and lateral radiographs of the thoracic and lumbar spine were reviewed by two trained rheumatologists using the semiquantitative (SQ) method described by Genant et al. [J. Bone Miner Res. 8 (1993) 1137]. Vertebral deformities that could be related to causes other than osteoporosis (i.e., Scheuermann's disease or osteoarthritis) were disregarded. The final analysis was made over 745 women after excluding 25 women whose spine radiographs were incomplete or of poor quality. The sample average age was 80.1 +/- 3.4 years. Vertebral fractures were found in 170 women: 22.8% (95% CI, 19.8-25.8%). A single, two, three, or more vertebral fractures were seen in 99 (58.2%), 43 (25.3%), and 28 (16.5%) of the 170 affected women, respectively. The prevalence of vertebral fractures increased with age from 19.0% (95% CI, 14.9-23.1%) among women 75-79 years old to 21.9% (95% CI, 17.3-26.5%) among those 80-84 years old and to 41.4%(95% CI, 31.0-51.7%) among those 85 years of age and over (Chi-square test for trend P < 0.00016). A significant correlation was found also between the number of vertebral fractures per woman and age (r = 0.108, P = 0.003) and between the spinal fracture index and age (r = 0.105, P = 0.004). We conclude that the prevalence of vertebral fractures is high in French ambulatory elderly women, which confirms the results of previous studies conducted in various Caucasian and Asian populations.

Distribution of bone mineral density at the proximal tibia in knee osteoarthritis.

One hundred and thirteen knees with osteoarthritis (OA) were studied to assess the distribution of bone mineral density (BMD) in the proximal tibia and the potential relation between osteoarthritis and osteoporosis in evaluating hip BMD. All patients had severe knee pain and were diagnosed with Kellgren and Lawrence grade IV osteoarthritis. According to the magnitude of the axial deformity, four categories were created: varus>10 degrees ( 28.3%), varus 4-10 degrees (38.9%), aligned 180 +/- 3 degrees (13.3%), and valgus>4 degrees (19.5%). For each category, the medial and lateral proximal tibial density were assessed. BMD was measured at the femoral neck and at 14 regions of interest (ROI) in the proximal part of the tibia using dual X-ray absorptiometry. Based on the femoral neck BMD, patients were classified according to the World Health Organization (WHO) definition of osteoporosis. The mean knee BMD was positively correlated with the hip BMD value (knee BMD m = 0.38 + 0.73 x hip BMD, r = 0.60, P<0.001). The knee BMD distribution of the 113 patients was negatively correlated with the axial deformity (BMD MT-LT = 5.15 - 0.027 x HKA, r = 0.77, P<0.0001). In the varus deformity, BMD of the medial side was higher than that of the lateral side with an important asymmetry (0.587 g/cm2). This asymmetry was also found in the valgus deformity for the lateral side but was less important (-0.112 g/cm2). With equal deformity, the asymmetry of BMD was higher in varus deformity (0.587 g/cm2) than in valgus deformity (-0.112 g/cm2). Asymmetry of the knee BMD distribution revealed that progression of the deformity (either varus or valgus) with joint space narrowing led to an increase in the medio-lateral difference of the proximal tibia density. Lesser severity of Kellgren and Lawrence grades may reveal different results. Twenty patients with osteoporosis developed knee osteoarthritis (OA) and the relation between osteoporosis and knee OA remains unclear.

[Dual x-ray absorptiometry assessment of bone density of the proximal tibia in advanced-stage degenerative disease of the knee]. / Evaluation de la densité osseuse mesurée par absorbtiométrie biphotonique à rayons X DXA (dual x-ray absorbtiometry) de l'extrémité supérieure du tibia dans la gonarthose évoluée.

PURPOSE OF THE STUDY: Axial deformity secondary to degenerative joint disease of the knee can modify stress forces. Certain studies have reported an inversely proportional relationship between degenerative disease and osteoporosis. The aim of this prospective study was to quantify the horizontal linear distribution of bone density using dual x-ray absorptiometry (DXA) of the proximal tibia as a function of the femoral neck bone density in patients with knee osteoarthritis. MATERIAL AND METHODS: Between September 1996 and March 1998, 90 cases of primary degenerative joint disease of the knee were programmed for total knee arthroplasty. Prior to the procedure, the patients were assessed clinically and radiologically according to the International Knee Society (IKS) criteria. The mechanical femorotibial angle was measured in all patients and the varus angles were recorded. Most of the patients were women (65 p. 100) with a mean age of 70 +/- 5 years. Valgus knees were excluded from this series. The mean mechanical femorotibial angle was 172 +/- 5 degrees. Fifteen patients had a normal axis (16 p. 100), 32 had a varus measuring 4 degrees to 10 degrees (35 p. 100) and 43 had a varus measuring 10 degrees or more (48 p. 100). The overall varus distance was 6.4 +/- 2 cm. All patients had two DXA explorations: femoral neck to determine the bone status according to the WHO criteria (normal, osteopenia, osteoporosis), knee to determine the linear distribution of bone density of the proximal tibia. A 7 mm high band including 7 regions of interest covering the width of the tibia were explored in the area where the tibial cut was to be made. These 7 regions of interest were: R1, R2 under the lateral compartment, R6, R7 under the medial compartment, and R3, R4, R5 on either side of the tibial spines. The level of significance was set at 5 p. 100. RESULTS: The mean Z score (0.54 +/- 1) in the 90 patients showed a symmetrical distribution. These patients were representative of their age range. Their T score was - 1.40 +/- 1 (m +/- SD) and most had osteopenia (54 p. 100) according to the WHO criteria, although 16 p. 100 had osteoporosis. Mean bone density of the knee was 0.898 +/- 0.163 g/cm(3) and was correlated with that of the femoral neck (r=0.61, p=0.001). There were significant correlations between the differences in the bone densities of the knee compartments (R6-R2, R7-R1) and the mechanical femorotibial angle [(r=0.39, p=0.0001); (r=0.52, p=0.001)]. Irrespective of the overall bone density, there was a strong medial compartment overloading, which correlated with the degree of varus deformation. CONCLUSION: DXA assessment of bone mineral density of the proximal tibia is a simple, reliable, precise and reproducible method. The distribution of bone density in the degenerative knee depends on the degree of deformation. The average level depends on the subject's general state of mineralization. Osteoporosis does not protect against degeneration of the knee joint since 16 p. 100 of our patients had osteoporosis according to the WHO criteria.