Along with tissue damage, inflammation, and degenerative processes, central sensitization (spinal and supraspinal neuronal hyperactivity resulting from continuous nociceptive stimulation) plays an important role in the pathogenesis of chronic pain in rheumatic diseases (RDs). Functional magnetic resonance imaging (fMRI) makes it possible to visualize the central nervous system (CNS) parts involved in nociception and to diagnose central sensitization and its associated emotional and cognitive aspects of the experience of pain. Thus, fMRI for rheumatoid arthritis has revealed activation predominantly in the medial pain system, including the anterior cingulate gyrus, prefrontal cortex, and insula — the CNS structures that do not participate in the primary sensory discrimination assessment of pain, but determine its emotional assessment and the formation of pain behavior. The fMRI technique makes it possible to better understand the central mechanisms of chronic pain in RDs, to more accurately select drug and non-drug treatments, and to monitor their efficiency.

In modern rheumatology, comorbid infections have a significant impact on morbidity and mortality, especially in immuneinflammatory rheumatic diseases (IRDs). One of the ways to solve this problem is to study and actively use various vaccines. This paper analyzes the 2019 updated version of the European League Against Rheumatism (EULAR) recommendations for vaccination in adult patients with IRDs. It discusses the safety and immunogenicity of vaccination associated with the prevention of various infections in patients with IRDs. The basic directions of future investigations on this problem are outlined.

Objective: to analyze the clinical and organizational feasibility of using different intervention thresholds for the Russian population.

Subjects and methods. The probability of fractures using the Russian FRAX model was calculated on a sample of 3,866 postmenopausal female residents from 6 cities of the Russian Federation. Different intervention thresholds, including fixed (20% for major fractures and 3% for hip fractures), age-dependent (European and Russian) ones, as well as alternative models, were analyzed. The proportion of women to be treated was estimated using different intervention thresholds.

Results and discussion. The analysis of the effectiveness of the thresholds showed that the European threshold was the least appropriate one for the formed sample, since more than half (53.6%) of the women to be treated using the threshold, while the vast majority (90%) of the patients were in the younger age groups (50—54 years). There were very similar results of the effectiveness analysis of the fixed threshold (according to the USA National Osteoporosis Foundation — NOF) recommendations and that of the age-dependent threshold for Russia (in the context of the national clinical recommendations). Using the NOF approach in our sample could identify 47.8% of the postmenopausal women to be treated for osteoporosis. Their proportion rose from 29.6% of the patients aged 50—54 years to 80.6% of those aged 85 years and older. The alternative analyses of age-dependent thresholds showed great effectiveness when the fracture was considered not as a risk factor for future fractures, but as a clinical disease manifestation that was sufficient to recommend that the patient should be treated without FRAX counting. However, with their use, the proportion of older people to be treated remains not high enough. In this connection, there remains a need to search for the more adequate application of the existing intervention threshold or to develop a new, for example, hybrid variant of the age-dependent threshold.

Objective: to compare the clinical features of two groups of patients with early psoriatic arthritis (PsA): with the involvement of the axial skeleton and without axial lesion.

Subjects and methods. Examinations were made in 95 patients (47 men and 48 women) with early PsA from the Russian registry, the diagnosis met the CASPAR criteria; their mean age was 36.5+10.7 years; the duration of arthritis was 12.1 + 10.3 months. In addition to the standard examination, all the patients underwent evaluation of inflammatory back pain (IBP) (ASAS criteria), pelvic radiography, and determination of HLA-B27; 79 patients had additionally magnetic resonance imaging (MRI) of the sacroiliac joints (SIJ). Active sacroiliitis (SI) detected on MRI (MRI-SI) was identified as bone marrow edema (osteitis) in the STIR mode. Radiographic SI on (rSI) was recorded if there were bilateral or unilateral changes (Kellgren grades >II or >III, respectively). The results of radiography and MRI were assessed by an independent radiologist. The disease activity in patients with IBP was evaluated by BASDAI. patients’ global assessment of disease activity (GADA) and assessment of pain intensity (PI) were made using a 100 mm visual analogue scale (VAS). The patients were divided into two groups: 1) those with axial lesion (axPsA), who had IBP, and/or rSI, and/or MRI-SI; 2) those without axial lesion, who had only peripheral PsA (pPsA).

Results and discussion. IBP was found in 63 (66.3%) patients; it was transient, episodic in 35 (60.3%) from them. MRI-SI was detected in 28 (35.4%) from the 79 patients; rSI — in 29 (30.5%). The axPsA group included 65 (68.4%) patients and the pPsA group consisted of 30 (31.6%) patients. There was a preponderance of males in the axPsA group (60%) and that of females in the pPsA group (73.3%) (р=0.003). The patients with axPsA were younger than those with pPsA (33.9+9.6 and 41.7+10.6 years, respectively; p=0.0007). They were more frequently HLA-B27 positive than pPSA patients: 47.6% (n=30) and 23.3% (n=7) (p=0.02); and had shorter duration of arthritis: 10.3+8.7 and 16.1 + 11.7 months, respectively (p = 0.008).

In the axPsA group, of PI was worse than that in the pPsA group: GADA averaged 58.4+17.3 and 49.8+16.7 mm (p=0.02); PI >50 mm was observed in 44 (67.7%) and 13 (43.3%) patients, respectively [odds ratio (OR), 2.74; 95% confidence interval (CI), 1.13-6.67; p=0.026]. More severe skin lesions were seen in patients with axPsA than in those with pPsA: BSA >3% was detected in 24 (40.7%) and 4 (14.8%) patients (OR, 3.94; 95% CI, 1.21-12.86; p=0.023); the median PASI was 9.7 [6.6; 21.5] and 5.0 [0.0; 6.4] respectively (p=0.005). The patients with axPsA showed higher C-reactive protein (CRP) values than those with pPsA: CRP >5 mg/L was found in 58 (89.3%) and 19 (63.3%) patients, respectively (OR, 4.80; 95% CI, 1.63-14.13; p=0.004).

Conclusion. The targeted examination of PsA patients revealed axial lesion in 68% from them; delayed diagnosis was generally associated with the inconsistent character of IBP. Among the patients with axPsA, there are significantly more males, younger adults, and HLA-B27 carriers. With the involvement of the axial skeleton, there was a more severe course of the disease: worse PI, a greater severity of skin lesions, and higher CRP levels. Considering the need for early diagnosis of axPsA for the timely use of biological agents, studies of this problem should be continued using large patient cohorts.

Objective: to evaluate the role of the procalcitonin (PC) test in the diagnosis of infections in immune-mediated inflammatory rheumatic diseases (IIRDs).

Subjects and methods. The investigation enrolled 325 patients (216 women, 109 men) aged 2 to 82 years with different IIRDs. The serum PC concentration was determined by the quantitative electrochemiluminescence method using a Cobas E 411 analyzer (Roche, Switzerland).

Results and discussion. The infectious process was detected in 145 (44.6%) patients: generalized and local infections in 11 and 134 cases, respectively. Local infections were regarded as severe and mild in 61 and 73 cases, respectively. In patients with generalized infection, the median (Me) PC level was 3.6 [0.88; 11.3] ng/ml. In this group, the PC values exceeded 2 and 10 ng/ml in 73% and 27%, respectively. In severe local infection, the Me PC level was 0.33 [0.23; 0.88] ng/ml, in mild infection — 0.12 [0.05; 0.16] ng/ml. In 180 patients without infection, it was 0.11 [0.05; 0.17] ng/ml, whereas higher PC levels were found in adult onset Still's disease (0.39 [0.14; 0.51] ng/ml), systemic juvenile arthritis (0.17 [0.11; 0.56] ng/ml) and systemic lupus erythematosus (0.11 [0.06; 0.15] ng/ml). The level of PC was significantly higher in the patients with generalized infection than that in those without infection (p<0.0001), as well as in those with mild (p<0.0001) and severe (p<0.0001) local infection. The PC level was higher in patients with severe local infection than in those without infection (p<0.001) and in those with mild local infection (p=0.004). There were no significant differences in PC levels in the patients with mild local infection and in those without infection. The ROC analysis showed that the diagnostic significance of PC determination was excellent in generalized infection, very good in severe local infection, and very good when differentiating generalized from local infection.

Conclusion. Measuring PC is sure to contribute to the diagnosis of generalized and severe local infections in patients with IIRDs. However, when interpreting the PC values, it is necessary to take into account the pooled data: a specific rheumatic nosological entity and clinical, laboratory, and instrumental findings. The multimarker approach can be considered as a promising way to diagnose infections in IIRDs.

In recent years, arterial stiffness has been shown to be increased in ankylosing spondylitis (AS). However, this issue has not been sufficiently studied today.

Objective: to investigate central aortic pressure values and pulse wave velocity (PWV) in patients with AS and their relationship to the clinical manifestations of the disease.

Subjects and methods. A total of 47 patients (mean age 37.0+10.1) with AS were examined. ASDAS-CRP averaged 3.2+0.9; the duration of AS was 6.0+4.6 years; and the radiographic stage of sacroiliitis was 2.3+1.4. A control group included 33 healthy individuals. The groups were matched for age, gender, and office blood pressure (BP). Central aortic pressure and PWV were determined by applanation tonometry on a SphygmoCor apparatus (AtCorMedical, Australia). The Mann-Whitney U test and the Spearman correlation coefficient test were used for statistical analysis.

Results and discussion. In the patients with AS, central systolic and diastolic BP was significantly higher than that in the controls (115.4+14.04 and 101.1 + 10.2 mm Hg, p=0.00001 and 78.6+12.3 and 71.8+7.3 mm Hg respectively, p=0.001). The patients with AS showed a 15.01% increase in mean central aortic pressure values compared to the control group (106.5+13.7 and 92.6+9.4 mm Hg, respectively; p=0.0001). Carotid-femoral PWV averaged 6.6+1.7 m/sec in the patients with AS and 5.20+0.96 m/sec in the controls (p=0.0001). There was a direct correlation of PWV with the occiput-wall distance r= 0.36; p=0.01) and an inverse correlation with Schober's test (r=-0.54; p=0.0001).

Conclusion. The patients with AS were found to have increased arterial stiffness parameters, such as PWV, central aortic pressure, central diastolic BP, and central hemodynamic pressure. PWV was demonstrated to be related to clinical data.

Calcium pyrophosphate deposition disease (CPPD) is more common at an old age. The age-related features of the disease have not been studied.

Objective: to study age-related features of CPPD.

Subjects and methods. A total of 113 patients (54 men and 59 women) who had received inpatient or outpatient treatment at the V.A. Nasonova Research Institute of Rheumatology were retrospectively analyzed. The inclusion criteria were age older than 18 years, crystal-verified diagnosis of CPPD, and a signed informed consent.

The patients were divided into two groups: 1) older than 55 years (n=38) and younger than 55 years (n=75). The investigators compared the frequency of clinical symptoms, including phenotypes in accordance with the EULAR recommendations, the intensity of pain with a visual analogue scale (VAS), the need for symptomatic therapy, detection rates for chondrocalcinosis (CC) in the knee and wrist joints by radiography, anthropometric and laboratory (the serum levels of C-reactive protein (CRP), creatinine, uric acid, parathyroid hormone, magnesium, phosphorus, and total calcium) features, the presence of CPPD-associated factors (a history of joint injuries, family CC cases, hypomagnesemia, hyperparathyroidism (HPT), hemochromatosis, hypomagnesemia, rheumatoid arthritis (RA), gout, chronic kidney disease (CKD) Stage >3, and use of diuretics).

Results and discussion. Thirty-eight (33.6%) of the 113 examined patients with CPPD were aged less than 55 years. The most common clinical form of CPPD was chronic arthritis (n=54; 47.8%), the less common forms were osteoarthritis (OA) with calcium pyrophosphate (CPP) crystals (n=35; 31%) and acute arthritis (n=24; 21.2 %); their rates did not differ in the formed groups.

In patients older than 55 years, the pain intensity according to VAS was higher than that at a younger age (50 [40; 70] mm and 40 [25; 54] mm, respectively; p<0.001); they had more frequently to take nonsteroidal anti-inflammatory drugs (NSAIDs) and/or colchicine (94.7 and 76.3%, respectively; p=0.0039) and had a higher serum CRP level (4.1 [1.9; 10.3] and 2.1 [1.9; 10.3] mg/L, respectively; p=0.0034); however, the number of patients with a CRP concentration of >5 mg/dL was comparable for both groups. Family CPPD cases were recorded in two patients less than 55 years of age. Knee joint radiography significantly more frequently revealed CC in 65 (57.5%) patients aged older than 55 years than that at a younger age (68 and 36.8%, respectively; p=0.001). Hand radiography detected CC in 21 (18.6%) patients, it was also more common in those aged older than 55 years (25.3 and 5.3%, respectively; p=0.001).

The CPPD-associated factors include OA, gout, HPT, RA, and CKD >3 Stage; these diseases detected in this study were seen in 91 (80.5%), 28 (24.8%), 14 (12.4%), 5 (4.4%), and 12 (11%) cases, respectively. There were no significant differences in the detection rates for these diseases in patients younger and older than 55 years of age. Also, one patient had hypomagnesemia and one patient had hemochromatosis; both were younger than 55 years old.

Conclusion. The prevalence of CPPD at a young age can be underestimated: 33.6% of the patients with CPPD confirmed by the detection of CPP crystals in synovial fluid were aged less than 55 years. Moreover, the frequency of individual phenotypes and main CPPD-associated factors is identical in different age groups. At the age of older than 55 years, CPPD is characterized by the more frequent detection of radiographic signs of CC, a greater need for NSAIDs and colchicine, and a high level of CRP.

Objective: to investigate bone mineral density (BMD) status and the factors influencing the latter in reproductive-aged women with rheumatic diseases (RDs).

Subjects and methods. The investigation enrolled 134 women (mean age, 35 [29; 43] years): 94 patients with RDs (rheumatoid arthritis (RA), systemic sclerosis (SS), and psoriatic arthritis (PsA)) and 40 people without RDs. The investigators conducted a survey using a unified questionnaire, spine and proximal femur bone densitometry by dual energy X-ray absorptiometry (Hologic Discovery A Bone densitometer, USA), serum vitamin D measurement, and daily dietary calcium intake estimation.

Results and discussion. Reduced BMD was detected significantly more often in the group of patients with RDs compared with the healthy control (25 and 8%, respectively; p=0.0213). It occurred in 48% of patients with RA, in 21% of those with SS, and in 15% of those with PsA. Patients with RDs showed a direct correlation of BMD in all areas of measurement with height, weight, body mass index, and serum vitamin D concentration and an inverse correlation with the cumulative dose of glucocorticoids. In addition, an inverse correlation was found between proximal femur BMD and RD duration. The patients with SS displayed an inverse relationship between BMD of both proximal femurs and C-reactive protein level; and the women with RA had exhibited this relationship between lumbar spine and femoral neck BMD and ESR.

Conclusion. In general, 25% of reproductive-aged women with RDs need osteoporosis monitoring and prevention, and, in the presence of fractures, antiosteoporotic treatment.

Osteoarthritis (OA) is one of the most common diseases of the musculoskeletal system in the world. Some researchers call the small joints of the hands as being one of the most common sites of involvement in OA. Its most severe phenotype is considered to be inflammatory, or erosive, OA (EOA). Nevertheless, the radiographic pattern of this disease has not yet been sufficiently studied, and whether EOA is an independent form of OA, a regular later stage of the disease or an individual nosological entity, has not yet been resolved.

Objective: to assess the location, frequency, and severity of radiographic symptoms and pain in patients with EOA and non-erosive OA (NEOA), to study the involvement of carpometacarpal (CMC), wrist, metacarpophalangeal (MCP) and radiocarpal (RC) joints in the pathological process in patients with EOA and NEOA of the hands.

Subjects and methods. The investigation enrolled 64 women with hand OA who met the American College of Rheumatology (ACR) OA criteria. Hand joint images in the anteroposterior projection were first performed in all the patients. Each patient completed the AUSCAN questionnaire. The images were described according to the Kellgren and Lawrence classification. The mean age of the patients was 65.28+6.82 years; the age at onset of the disease was 48.81+7.73 years; its median OA duration was 15.0 [10.0; 19.5] years. According to the presence of erosions in the interphalangeal joints (IPJ) of the hand, the patients were divided into two groups: 1) EOA (n=23); 2) NEOA (n=37). Both groups were matched for age and disease duration (the mean age of patients with EOA was 68+6.15 years, the mean disease duration was 18.34+7.11 years; these in the NEOA group were 65.13+5.43 and 16.56+8.4 years, respectively). For age matching, 4 patients were excluded from Group 2.

Results and discussion. Kellgren and Lawrence Stage II hand OA was detected most frequently (49%) and the most common radiographic symptoms of OA in the distal IPJ (DIPJ), proximal IPJ (PIPJ) and MCP joints were joint space narrowing (JSN) (100%, 100%, and 95%, respectively) and osteophytes (OPs) (88%, 70%, and 45% respectively). The least common conditions were subchondral osteosclerosis (SCOS) (5%), erosions (8%), and subluxations (3%) in the MCP joints, as well as subluxations in the PIPJ (6%). In the wrist, the most frequent sites of involvement was first CMCJ and scaphoid-trapezium-trapezoid joint (STTJ); their JSN was identified in 86 and 69% of patients, respectively; OPs were found respectively in 81 and 50% of cases. Changes in the RC joint (RCJ) were least common.

EOA of the DIPJ and PIPJ was found in 15 (23%) patients with radiographic changes corresponding to Stages III—IV OA of the hand and in 8 (12%) patients with Stage II according to the Kellgren and Lawrence classification. The DIPJ in EOA versus NEOA showed significantly higher frequency of OPs (100 and 78%), SCOS (74 and 11%), cysts (61 and 24%), and subluxations (43 and 14%); the PIPJ — SCOS (43 and 5%), cysts (52 and 27%), and subluxations (17 and 0%; p <0.05); the first CMCJ — JSN (96 and 68%), SCOS (61 and 22%), erosions (26 and 3%), and subluxations (39 and 14%), the STTJ, — SCOS (22 and 3%) and erosions (62 and 16%, respectively; p <0.05). According to the AUSCAN questionnaire, a significantly greater pain severity was recorded in patients with EOA than in those with NEOA (65 and 30%; p=0.008).

Conclusion. DIPJs are most frequently affected by hand OA. The most common radiographic symptoms are JSN and OPs. In the wrists, first CMCJ and STTJ are most often involved; there are practically no changes in the RCJ. In EOA versus in NEOA, there are significantly more common OPs, cysts, SCOS, and subluxations in the DIPJs, SCOS, cysts, and subluxations in the PIPJs; first CMCJ and STTJ are significantly more often involved in the pathological process. EOA compared with NEOA is characterized by more severe pain, as evidenced by the AUSCAN questionnaire.

The paper presents the results of a double-blind (BCD-085-3/AILAS) phase II clinical trial of the original interleukin 17A (IL17A) inhibitor BCD-085 prescribed at different doses to patients with active ankylosing spondylitis (AS) and those of an extended (BCD-085-3ext/AILAS-II) trial characterizing the efficacy and safety of this drug when used for a year.

The objective of the AILAS study is to determine the therapeutically effective and safe dose of BCD-085 in the treatment of active AS. The efficacy, safety, and immunogenicity of BCD-085 during its annual use were additionally evaluated in the extended trial.

Subjects and methods. The investigation enrolled 89 patients diagnosed as having active (BASDAI scores >4.0; mean spinal pain scores >4.0) AS that met the 1984 New York classification criteria. After the end of the screening period, the patients were randomized at a ratio of 1:1:1:1 in one of four groups that received 40; 80 or 120 mg of BCD-085 subcutaneously or placebo on day 1 of weeks 0, 1, 2 and then once every two weeks up to week 12. The primary end point was the number of patients who achieved an ASAS20 response at week 16. The investigation evaluated the safety of the drug, by calculating the total incidence of adverse events (AEs) and serious AEs (SAEs) and the number of cases of premature therapy termination because of AEs.

Results and discussion. An ASAS20 response at week 16 was achieved in 72.7% of patients receiving 40 mg of BCD-085, in 81.8% of those receiving 80 mg, in 90.9% of those receiving 120 mg, and in 42.9% of cases in the placebo group (p=0.004). The superiority of BCD-085 over placebo was proven for 80- and 120-mg doses. The fastest and most pronounced effect was observed in patients treated with 120 mg of BCD-085. In the extended study, an ASAS20 response at week 52 was recorded in 86.4% of patients. One or more AEs during the first 16 weeks of therapy were reported in 11 (50.0%) patients of the 40-mg group; in 6 (27.3%) of the 80 mg group; in 4 (18.2%) of the 120 mg group and in 7 (31.8%) of the placebo group (p=0.183). The frequency and spectrum of AEs did not significantly differ in patients who received placebo and BCD-085 in different doses. No SAE was recorded.

Conclusion. Phase II study yielded data demonstrating the high efficacy and good tolerance of BCD-085 in the treatment of active AS. The best effect and optimal tolerance were demonstrated for a dose of 120 mg.

The paper describes diagnostic technology for inflammatory changes in the spine and sacroiliac joints using magnetic resonance imaging if axial spondyloarthritis is present or during a followup.

Rheumatic diseases are caused by chronic autoimmune processes that require long-term therapy, which leads to the formation of resistance to the drugs used. The search for new approaches to their treatment in recent years has been enriched with the use of cell therapy methods. They are considered in this review of the literature and include the transplantation of hematopoietic stem cells, mesenchymal stem (stromal) cells, the induction or administration of T-regulatory cells, tolerogenic dendritic cells. The paper discusses methods of obtaining cell products, their safety and clinical use in patients with systemic lupus erythematosus, systemic sclerosis, rheumatoid arthritis, and other rheumatic diseases, and treatment complications. Based on the analysis, the authors give the comparative characteristics of various types of tolerogenic cell therapy for rheumatic diseases and point out their advantages, disadvantages, and the specific features of clinical application.

The paper considers the evolution of knowledge of polymyalgia rheumatica (PR) since 1888 and presents dynamics in the creation of a unified terminology. It characterizes the diagnostic development process, by using the criteria by H.A. Bird et al. 1979, J.G. Jones and B.L. Hazleman 1981 (UK), T.Y. Chuang, G.G. Hunder et al. 1982 (USA), M. Nabunaga et al. 1989 (Japan), and L.A. Healey 1984 (USA) as an example. The author scrutinizes the validation of these criteria in different countries and then the process of developing international classification criteria for PR (under the auspices of the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR), by validating the new classification and previously existing diagnostic criteria.

The review analyzes publications on the specific features of the progression of shoulder joint damage in patients with rheumatoid arthritis (RA) and on the surgical treatment of these patients. Progressive shoulder joint structural changes in RA are accompanied by the formation of articular surface erosions, as well as by damage to the rotator cuff tendons. Several classifications of shoulder joint injuries are described. Reverse shoulder replacement is the surgery of choice in these patients.

Knee arthroplasty (KAP) is a cost-effective and reliable treatment for knee osteoarthritis with the predicted increase in demand. Clinical assessment systems for the effectiveness of rehabilitation do not fully reflect the recovery process, but the evaluation of biomechanical gait parameters is most objective.

Objective: to study of the changes in the biomechanical gait parameters after KAP for osteoarthritis.

Subjects and methods. A total of 54 patients (31 women and 23 men; mean age, 63.86+1.69 years) were examined an average of 3.94+1.40 months after KAP at the Ivanovo Regional Hospital for War Veterans. A control group consisted of 49 people (28 women and 21 men; mean age, 34.6+8.8 years). Walking performance was studied three times: at admission, one and two weeks after the end of a cycle. Gait parameters were recorded using a Stedis feedback walking simulator (OOO “Neurosoft”, Ivanovo, Russia) in the Assessment package (Registration certificate No. РЗН 2018/7458 dated 08.07.2018). The results were processed using the standard biomedical statistical methods at a significance level of 5%.

Results and discussion. In the early recovery period, the patients’ walking after KAP was characterized by decreased speed, by the symptoms of unloading, and by a slight lower extremity functional asymmetry. The revealed phenomena were suggestive of both positive changes in the recovery process as a whole and the normalization of the temporal pattern of a step cycle. It was established that walking speed and the double support period of gait were not restored 3 months after KAP. The main biomechanical changes were non-specific and were associated with reduced walking speed. It was suggested that physical therapy should be aimed mainly at increasing the stride length when controlling dynamic loads. The criterion for the effectiveness of rehabilitation was to reduce asymmetry when walking.

Tumor-induced hypophosphatemic osteomalacia is a rare disease and its diagnosis presents certain difficulties. This is primarily due to small tumor size and to the absence of local clinical symptoms. Adult-onset newly diagnosed hypophosphatemia concurrent with hyperphosphaturia is a sign of tumor-induced hypophosphatemic osteomalacia. The paper describes a female patient with fibroblast growth factor 23-secreting tumor of the upper third of the femur. After tumor removal, pharmacological treatment involves prescribing calcium supplements and active vitamin D metabolite until normal bone mineral density is restored.