Bisphosphonate Use and the Risk of Undergoing Total Knee Arthroplasty in Osteoporotic Patients with Osteoarthritis: A Nationwide Cohort Study in Taiwan

Effect of Intravenous Zoledronic Acid on Total Knee Replacement in Patients With Symptomatic Knee Osteoarthritis and Without Severe Joint Space Narrowing: A Prespecified Secondary Analysis of a Two-Year, Multicenter, Double-Blind, Placebo-Controlled Clinical Trial

OBJECTIVE

To determine the effect of zoledronic acid (ZA) on the risk of total knee replacement (TKR) in patients with symptomatic knee osteoarthritis and without severe joint space narrowing (JSN).

METHODS

We included 222 participants (mean age 62 years, 52% female) from the two-year Zoledronic Acid for Osteoarthritis Knee Pain trial (113 received 5 mg of ZA annually and 109 received placebo) conducted between November 2013 and October 2017. Primary TKR were identified until February 22, 2022. The effect of ZA on TKR risk was evaluated using Cox proportional hazard regression models. Because the treatment effect failed the proportional hazards assumption, a time-varying coefficients analysis for treatment was conducted by splitting the study into two periods (ie, within and after two years of randomization).

RESULTS

Over a mean follow-up of seven years, 39% and 30% of participants had any TKR in the ZA and placebo groups, and 28% and 18% had TKR in the study knee, respectively. Use of ZA was associated with a higher risk of TKR in any knee (hazard ratio [HR] 4.2, 95% confidence interval [CI] 1.2-14.7) and showed a trend in the study knee (HR 6.8, 95%CI 0.9-53.9) during the trial. In the posttrial period, the risk of TKR was similar in the ZA and the placebo groups for any knee (HR 1.2, 95%CI 0.5-1.8) and the study knee (HR 1.4, 95%CI 0.5-2.2).

CONCLUSION

These results suggest that ZA is not protective against TKR in patients with symptomatic knee osteoarthritis and without severe JSN.

Initiation of Bisphosphonates Prior to Total Joint Arthroplasty Does Not Lower Periprosthetic Fracture Risk

BACKGROUND

Many patients are diagnosed with osteoporosis shortly prior to scheduling total joint arthroplasty (TJA). The purpose of this study was to determine if initiation of bisphosphonates prior to TJA decreased the risks of periprosthetic fractures (PPFx).

METHODS

A national database was used to identify all patients diagnosed with osteoporosis prior to primary TJA. Patients who had osteoporosis without preoperative bisphosphonate use were designated as our control group. Patients on preoperative bisphosphonates were stratified based on duration and timing of bisphosphonate use: long-term preoperative users (initiation 3 to 5 years preoperatively), intermediate-term preoperative users (initiation 1 to 3 years preoperatively), and short-term preoperative users (initiation 0 to 1 year preoperatively). Rates of PPFx at 90-day and 2-year follow-up were compared between groups.

RESULTS

In patients undergoing primary total hip arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .12) and 2-year follow-up (P = .22). In patients undergoing primary total knee arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .76) and 2-year follow-up (P = .39).

CONCLUSIONS

In patients undergoing primary TJA, preoperative bisphosphonate users did not have a decreased PPFx rate compared to our control group at 90-day and 2-year follow-up. Our findings suggest that preoperative bisphosphonate use, regardless of the duration of treatment, does not confer protective benefits against PPFx in patients undergoing TJA.

LEVEL OF EVIDENCE

Prognostic Level III.

Postoperative Bisphosphonates Use is Associated with Reduced Adverse Outcomes After Primary Total Joint Arthroplasty of Hip and Knee: A Nationwide Population-Based Cohort Study

Bisphosphonates have been associated with a decreased risk of revision surgery after total joint arthroplasty of the hip or knee (TJA) because of their effects on decreased periprosthetic bone loss and prosthetic migration. However, the results in the early literature are inconsistent, and the influence of bisphosphonates on associated complications and subsequent TJA remains unknown. This study investigated the association between the use of bisphosphonates and the risk of adverse outcomes after primary TJA. This matched cohort study utilized the National Health Insurance Research Database in Taiwan to identify patients who underwent primary TJA over a 15-year period (January 2000-December 2015 inclusive). Study participants were further categorized into two groups, bisphosphonate users and nonusers, using propensity score matching. The Kaplan-Meier curve analysis and adjusted hazard ratios (aHRs) of revision surgery, adverse outcomes of primary surgery and subsequent TJA were calculated using Cox regression analysis. This study analyzed data from 6485 patients who underwent total hip arthroplasty (THA) and 20,920 patients who underwent total knee arthroplasty (TKA). The risk of revision hip and knee arthroplasty was significantly lower in the bisphosphonate users than in the nonusers (aHR, 0.54 and 0.53, respectively). Furthermore, the risk of a subsequent total joint arthroplasty, adverse events and all-cause mortality were also significantly reduced in the bisphosphonate users. This study, involving a large cohort of patients who underwent primary arthroplasties, revealed that bisphosphonate treatment may potentially reduce the risk of revision surgery and associated adverse outcomes. Furthermore, the use of bisphosphonates after TJA is also associated with a reduced need for subsequent arthroplasty.Research Registration Unique Identifying Number (UIN): ClinicalTrials.gov Identifier-NCT05623540 ( https://clinicaltrials.gov/show/NCT05623540 ).

Effect of Osteoporosis Treatments on Osteoarthritis Progression in Postmenopausal Women: A Review of the Literature

PURPOSE OF REVIEW

The purpose of this literature review was to determine if medications used to treat osteoporosis are also effective for treating osteoarthritis (OA).

RECENT FINDINGS

A total of 40 relevant articles were identified. Studies were categorized into those (1) discussing estrogen and selective estrogen receptor modulators (SERMs), (2) bisphosphonates, (3) parathyroid hormone (PTH) analogs, and (4) denosumab, and (5) prior review articles. A large amount of evidence suggests that estrogen and SERMs are effective at reducing OA symptoms and disease progression. Evidence suggests that bisphosphonates, the most common medications used to treat osteoporosis, can reduce OA symptoms and disease progression. In vivo studies suggest that PTH analogs may improve the cartilage destruction associated with OA; however, few human trials have examined its use for OA. Denosumab is approved to treat osteoporosis, bone metastases, and certain types of breast cancer, but little study has been done with respect to its effect on OA. The current evidence indicates that medications used to treat osteoporosis are also effective for treating OA. Estrogen, SERMs, and bisphosphonates have the most potential as OA therapies. Less is known regarding the effectiveness of PTH analogs and denosumab in OA, and more research is needed.

Decreased stress shielding with poly-ether-ether-ketone tibial implant for total knee arthroplasty - A preliminary study using finite element analysis

In total knee arthroplasty (TKA), the mechanical mismatch between cobalt-chromium (CoCr) alloy tibial implant and bone has been implicated in stress shielding and subsequent implant failure and bone resorption. This study investigates the biomechanical advantages of poly-ether-ether-ketone (PEEK) tibial implant, which exhibit properties analogous to those of the surrounding bone. A finite element analysis (FEA) was employed to assess and compare the biomechanical performances of PEEK and CoCr tibial implants in patients with and without osteoporosis. Four FEA models were constructed with PEEK and CoCr alloy implants in normal and osteoporotic tibias. Based on previous literature and our clinical experience, stresses measurements were taken at 16 points on the tibial plateau and 8 points on the two surfaces which were 10 mm and 20 mm apart from the tibial plateau, with specific regions quantified for stress shielding. The results showed significant differences in stress distribution between PEEK and CoCr implants. The PEEK implants exhibited higher equivalent stresses on the tibial plateau in all models (normal bone: 0.22 ± 0.07 MPa vs. 0.13 ± 0.06 MPa, p < 0.01; osteoporotic bone: 0.39 ± 0.06 MPa vs. 0.17 ± 0.07 MPa, p < 0.01). In non-osteoporotic models, the mean equivalent stresses on proximal tibial surfaces were similarly elevated for PEEK implants (0.29 ± 0.13 MPa vs. 0.21 ± 0.08 MPa, p = 0.02). The CoCr implants demonstrated more stress shielding across all measured regions (tibial plateau: 23.47% vs. 2.73%; surface 1: 15.93% vs. 1.37%; surface 2: 10.71% vs. 6.56%). These disparities were even more pronounced in osteoporotic models in the CoCr group (tibial plateau: 32.50% vs. 8.36%). The maximum equivalent stresses on the tibial plateau further supported this trend (normal bone: 1.02 MPa vs. 0.52 MPa; osteoporotic bone: 1.43 MPa vs. 0.67 MPa). These data confirm the hypothesis that a PEEK tibial implant can reduce peri-prosthetic stress shielding, suggesting that PEEK implants have the capability to distribute loads more uniformly and maintain a closer approximation to physiological conditions.

Association between bone marrow lesions and bone mineral density of the proximal tibia in end-stage osteoarthritic knees

This retrospective cross-sectional study investigated the association between bone marrow lesions (BMLs) and bone mineral density (BMD) in the proximal tibia of end-stage osteoarthritic knees from a large patient sample. Overall, 1308 end-stage osteoarthritic knees were enrolled before total knee arthroplasty. The preoperative range of motion was recorded. Bone mineral density in the medial tibial plateau (MTP), lateral tibial plateau (LTP), and metaphysis were measured using dual-energy X-ray absorptiometry. The MTP/LTP, MTP/metaphysis, and LTP/metaphysis ratios were calculated. BMLs were scored using a whole-organ magnetic resonance imaging scoring system. The relationship between BMD and BML scores was investigated using linear regression analysis. The highest BMD was 0.787 ± 0.176 g/cm² at the MTP, followed by 0.676 ± 0.180 g/cm² and 0.572 ± 0.145 g/cm² at the metaphysis and LTP, respectively. The prevalence of BMLs was 90.4% and 24.2% in the MTP and LTP, respectively. In women, higher BML scores at the MTP were positively correlated with the BMD of the MTP (p < 0.001, r = 0.278), MTP/LTP (p < 0.001, r = 0.267), and MTP/metaphysis ratios (p < 0.001, r = 0.243). Regression analysis showed that higher BML scores in the MTP were correlated with higher BMD in the MTP (p < 0.001) and lower BMD in the LTP (p < 0.001). High BML scores in the MTP were positively associated with high BMD in the MTP, which also induced the medial to lateral imbalance of BMD in the proximal tibia.

The effect of postmenopausal osteoporosis on subchondral bone pathology in a rat model of knee osteoarthritis

This study aimed to investigate the additional effect of ovariectomy-induced osteoporosis (OP) on the pathology of knee osteoarthritis (OA) in a rat meniscectomized model, particularly focusing on subchondral bone changes and pain behaviour. Rats were divided into four groups, sham, OP, OA, OP plus OA, and assessed for histology, osteoclast activity, subchondral bone microstructure, and pain-related behaviour. Rats with OP plus OA had significantly increased calcified cartilage and subchondral bone damage scores, increased densities of subchondral osteoclasts in the weight-bearing area, and more porous subchondral trabecular bone compared with rats with OA. Loss of tidemark integrity was observed most frequently in rats with OP plus OA. The density of subchondral osteoclasts correlated with the calcified cartilage and subchondral bone damage score in rats with OA (OA and OP plus OA). No significant differences in the receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) expression ratio in subchondral bone and pain-related behavioural tests were observed between rats with OA and rats with OP plus OA. In rats with OA, coexisting OP potentially aggravated OA pathology mainly in calcified cartilage and subchondral trabecular bone by increasing subchondral osteoclast activity.

Effects of medications on incidence and risk of knee and hip joint replacement in patients with osteoarthritis: a systematic review and meta-analysis

Background

This systematic review and meta-analysis aimed to investigate the incidence and risk of knee and hip replacement in patients with osteoarthritis (OA) treated with different medications.

Methods

OVID MEDLINE, OVID EMBASE, Cochrane and Web of Science electronic databases were searched from inception to May 4th, 2022. Clinical trials, including randomized controlled trials, cohort studies and case–control studies, were selected. The meta-analysis effect size was estimated using either incidence with 95% confidence intervals (CIs) or odds ratio (OR)/relative risk (RR) with 95% CIs. The risk of bias and heterogeneity among studies were assessed and analyzed.

Results

Forty studies were included, involving 6,041,254 participants. The incidence of joint replacement in patients with OA varied according to the study design and treatments. The incidence of knee arthroplasty varied from 0 to 70.88%, while the incidence of hip arthroplasty varied from 11.71 to 96.43%. Compared to non-users, bisphosphonate users had a reduced risk of knee replacement (RR = 0.71, 95% CI: 0.66–0.77; adjusted hazard ratio [aHR] = 0.76, 95% CI: 0.70–0.83). Compared to intra-articular corticosteroid users, hyaluronic acid (HA) users had a higher risk of knee arthroplasty (RR = 1.76, 95% CI: 1.38–2.25). No publication bias was observed.

Conclusions

Bisphosphonate treatment is associated with a reduced risk of knee replacement. More studies are needed to validate our results due to the limited number of eligible studies and high heterogeneity among studies.

Bisphosphonate use is associated with a decreased joint narrowing rate in the non-arthritic hip

Aims

The preventive effects of bisphosphonates on articular cartilage in non-arthritic joints are unclear. This study aimed to investigate the effects of oral bisphosphonates on the rate of joint space narrowing in the non-arthritic hip.

Methods

We retrospectively reviewed standing whole-leg radiographs from patients who underwent knee arthroplasties from 2012 to 2020 at our institute. Patients with previous hip surgery, Kellgren–Lawrence grade ≥ II hip osteoarthritis, hip dysplasia, or rheumatoid arthritis were excluded. The rate of hip joint space narrowing was measured in 398 patients (796 hips), and the effects of the use of bisphosphonates were examined using the multivariate regression model and the propensity score matching (1:2) model.

Results

A total of 45 of 398 (11.3%) eligible patients were taking an oral bisphosphonate at the time of knee surgery, with a mean age of 75.8 years (SD 6.2) in bisphosphonate users and 75.7 years (SD 6.8) in non-users. The mean joint space narrowing rate was 0.04 mm/year (SD 0.11) in bisphosphonate users and 0.12 mm/year (SD 0.25) in non-users (p < 0.001). In the multivariate model, age (standardized coefficient = 0.0867, p = 0.016) and the use of a bisphosphonate (standardized coefficient = −0.182, p < 0.001) were associated with the joint space narrowing rate. After successfully matching 43 bisphosphonate users and 86 non-users, the joint narrowing rate was smaller in bisphosphonate users (p < 0.001).

Conclusion

The use of bisphosphonates is associated with decreased joint degeneration in non-arthritic hips after knee arthroplasty. Bisphosphonates slow joint degeneration, thus maintaining the thickness of joint cartilage in the normal joint or during the early phase of osteoarthritis. Cite this article: Bone Joint Res 2022;11(11):826–834.

Endothelial PDGF-BB/PDGFR-β signaling promotes osteoarthritis by enhancing angiogenesis-dependent abnormal subchondral bone formation

The mechanisms that coordinate the shift from joint homeostasis to osteoarthritis (OA) remain unknown. No pharmacological intervention can currently prevent the progression of osteoarthritis. Accumulating evidence has shown that subchondral bone deterioration is a primary trigger for overlying cartilage degeneration. We previously found that H-type vessels modulate aberrant subchondral bone formation during the pathogenesis of OA. However, the mechanism responsible for the elevation of H-type vessels in OA is still unclear. Here, we found that PDGFR-β expression, predominantly in the CD31^hiEmcn^hi endothelium, was substantially elevated in subchondral bones from OA patients and rodent OA models. A mouse model of OA with deletion of PDGFR-β in endothelial cells (ECs) exhibited fewer H-type vessels, ameliorated subchondral bone deterioration and alleviated overlying cartilage degeneration. Endothelial PDGFR-β promotes angiogenesis through the formation of the PDGFR-β/talin1/FAK complex. Notably, endothelium-specific inhibition of PDGFR-β by local injection of AAV9 in subchondral bone effectively attenuated the pathogenesis of OA compared with that of the vehicle-treated controls. Based on the results from this study, targeting PDGFR-β is a novel and promising approach for the prevention or early treatment of OA.

Femur and Tibia BMD Measurement in Elective Total Knee Arthroplasty Candidates

Distal femur BMD declines ∼20% following total knee arthroplasty (TKA) potentially leading to adverse outcomes. BMD knowledge before and following TKA might allow interventions to optimize outcomes. We hypothesized that distal femur and proximal tibial BMD could be reproducibly measured with existing DXA technology. Elective TKA candidates were enrolled and standard clinical DXA plus bilateral PA and lateral knee scans acquired. Manual regions of interest (ROIs) were placed at distal femur and proximal tibia sites based on required TKA machining and periprosthetic fracture location. Intra- and inter-rater BMD reliability was assessed by intra-class correlation (ICC). Custom and standard proximal femur BMD were correlated by linear regression and paired t test evaluated BMD differences between planned surgical and contralateral side. One hundred subjects (68F/32M), mean (SD) age and BMI of 67.2 (7.7) yr and 30.8 (4.8) kg/m² were enrolled. Lowest clinical BMD T-score was < -1.0 in 65% and ≤ -2.5 in 16%; 34 had prior fracture. BMD reproducibility at all custom ROIs was excellent; ICC > 0.96. Mean BMD at custom ROIs ranged from 0.903 to 1.346 g/cm² in the PA projection and 0.891 to 1.429 g/cm² in the lateral. Lower BMD values were observed at the proximal tibia, while the higher measurements were at the femur condyle. Custom knee ROI BMD was highly correlated (p < 0.0001) with total and femur neck with better correlation at ROIs adjacent to the joint (R² = 0.62-0.67, 0.49-0.55 respectively). In those without prior TKA (n = 76), mean BMD was lower (2.8%-6.6%; p < 0.05) in the planned surgical leg at all custom ROIs except the PA tibial regions. Individual variability was present with 82% having a custom ROI with lower BMD (up to 53%) in the planned operative leg. Distal femur and proximal tibial BMD can be measured using custom ROIs with good reproducibility. Suboptimal bone status is common in TKA candidates and distal femur/proximal tibia BMD is often lower on the planned operative side. Routine distal femur/proximal tibial BMD measurement might assist pre-operative interventions, surgical decision-making, subsequent care and outcomes. Studies to evaluate these possibilities are indicated.

Intravenous bisphosphonates do not improve knee pain or bone marrow lesions in people with knee osteoarthritis: a meta-analysis

OBJECTIVE

To summarise effects of intravenous bisphosphonates (IVBP) in patients with symptomatic knee osteoarthritis (OA) and bone marrow lesions (BMLs), using a meta-analysis of randomized controlled trials (RCTs).

METHODS

Literature databases were searched for placebo-controlled RCTs of IVBPs for knee OA from inception, and included validated pain and function scales, BML size, and incidence of adverse events. Efficacy was compared using standardized mean differences (SMD) and risk ratios (RR) with fixed-effect or random-effects models. Methodological quality was assessed using the Cochrane risk of bias tool, heterogeneity was assessed by I2 statistics.

RESULTS

We included 428 patients in 4 RCTs of 2-24 months duration; most patients (84%) received zoledronic acid (ZA). Risk of bias was low-moderate. IVBP had large effect sizes on pain within 3 months (SMD= -2.33 (95% confidence interval= -3.02, -1.65)) mainly driven by neridronate (resulting in substantial heterogeneity, I 2=92%) with no effect for ZA alone. Differences in knee function were statistically significant at 3 months (SMD=-0.22 (-0.43, -0.01), I 2=0.2%). Effect sizes for pain did not reach statistical significance at any other time point. IVBPs improved a semi-quantitative measure of BML size within 6 months (SMD= -0.52 (-0.89, -0.14), I 2=0%) but not at 12 months or two years. Adverse events (RR = 1.19 (1.00, 1.41) I 2=52%), occurred more frequently with IVBP.

CONCLUSION

ZA has no effect on knee pain, possibly a short-term effect on BML size and higher rates of adverse events. Neridronate may improve pain in the short term, but this is based on a single trial.

High prevalence and undertreatment of osteoporosis in elderly patients undergoing total hip arthroplasty

We detected a high prevalence of low bone mineral density assessed by DXA in 268 elderly patients with end-stage osteoarthritis scheduled for total hip arthroplasty (18% osteoporosis, 41% osteopenia). Therefore, and due to the identified concomitant undertreatment, routine DXA measurements should be considered in elderly patients prior to surgery.

INTRODUCTION

Bone quality represents a decisive factor for osseointegration, durability, and complications of an implanted prosthesis. Although the risk of osteoporosis increases with age and the assessment of bone mineral density (BMD) prior to total hip arthroplasty (THA) is recommended in elderly patients, a systematic, unbiased analysis of such patients is not available in the literature.

METHODS

In this retrospective study, we examined 268 elderly patients (age ≥70 years) who underwent dual-energy X-ray absorptiometry (DXA) within 3 months prior to primary THA. Demographics, medical history, radiographic OA grade, and stem fixation method (i.e., cemented or cementless) were obtained.

RESULTS

In total, 153 (57%) cemented and 115 (43%) cementless stem fixations during THA were performed. Forty-nine patients (18%) were diagnosed with osteoporosis (T-score ≤-2.5), 110 patients (41%) with osteopenia (T-score ≤-1.0), and 109 patients (41%) with normal BMD (T-score >-1.0). Importantly, 36/49 patients (73%) with osteoporosis were not diagnosed before, resulting in a relevant undertreatment. Female sex and low body mass index (BMI) were the main factors negatively influencing the bone mineral density (BMD).

CONCLUSIONS

Due to a high incidence of undiagnosed and untreated osteoporosis in elderly patients with potential effects on the success of osseointegration as well as other clinical outcomes, DXA measurements should be included in the clinical routine for these patients prior to THA.

Bisphosphonates, Bone and Joint Pain

PURPOSE OF REVIEW

Bisphosphonates (BPs) have an established role in a number of diseases including osteoporosis, but the role of BPs for treating symptomatic conditions other than bone metastases is less clear. We review recent data on the efficacy of BPs in the treatment of symptomatic bone and joint pain with osteoarthritis (OA) as an example.

RECENT FINDINGS

Although controversial, BPs have been reported to improve pain ratings, imaging features, and inflammatory markers in patients with arthritis, more specifically OA. It is possible that their effects in periarticular bone strongly influence the complex inflammatory process within the joints. Recent data also suggests that they can potentially impact synovial and synoviocytes and macrophages. Although more studies are needed to define their contribution in clinical practice, increasing evidence suggests they hold an important function, especially in conditions with periarticular bone involvement such as OA. Although BPs are indicated primarily for prevention and treatment of osteoporosis, they can also have potential effects on the inflammatory process of other conditions, including OA. Improvements in pain scale ratings, periarticular findings through imaging, and inflammatory response suggest their potential extra-osteoporotic properties.

Relationship between abnormalities detected by magnetic resonance imaging and knee symptoms in early knee osteoarthritis

We investigated the prevalence of magnetic resonance imaging (MRI) findings and their relationship with knee symptoms in women without radiographic evidence of knee osteoarthritis (KOA). This cross-sectional cohort study included 359 Japanese women without radiographic evidence of KOA (Kellgren‒Lawrence grade < 2). All participants underwent T2-weighted fat-suppressed MRI of their knees. Structural abnormalities (cartilage damage, bone marrow lesions [BMLs], subchondral cysts, bone attrition, osteophytes, meniscal lesions, and synovitis) were scored according to the whole-organ MRI score method. Knee symptoms were evaluated using the Knee Injury and Osteoarthritis Outcome Score. Participants were divided into early and non-KOA groups based on early KOA classification criteria. Logistic regression analysis was performed to evaluate the relationship between MRI abnormalities and knee symptoms. Cartilage damage was the most common abnormality (43.5%). The prevalences of cartilage damage, BMLs, subchondral cysts, bone attrition, meniscal lesions, and synovitis were higher in patients with early KOA than in those without. Synovitis (odds ratio [OR] 2.254, P = 0.002) and meniscal lesions (OR 1.479, P = 0.031) were positively associated with the presence of early KOA. Synovitis was most strongly associated with knee pain and might be a therapeutic target in patients with early KOA.

The Development of Disease-Modifying Therapies for Osteoarthritis (DMOADs): The Evidence to Date

Osteoarthritis (OA) is a complex heterogeneous articular disease with multiple joint tissue involvement of varying severity and no regulatory-agency-approved disease-modifying drugs (DMOADs). In this review, we discuss the reasons necessitating the development of DMOADs for OA management, the classifications of clinical phenotypes or molecular/mechanistic endotypes from the viewpoint of targeted drug discovery, and then summarize the efficacy and safety profile of a range of targeted drugs in Phase 2 and 3 clinical trials directed to cartilage-driven, bone-driven, and inflammation-driven endotypes. Finally, we briefly put forward the reasons for failures in OA clinical trials and possible steps to overcome these barriers.

The predictive significance of bone mineral density on postoperative pain relief in knee osteoarthritis patients after total knee arthroplasty: A prediction model

BACKGROUND

Bone mineral density (BMD) may be an important factor affecting the clinical outcomes after total knee arthroplasty (TKA). However, further information regarding BMD in postoperative pain relief is not present yet. This study aims to gain further insight into the predictive significance of BMD in postoperative pain relief in knee osteoarthritis (KOA) patients after TKA.

METHODS

156 KOA patients treated by TKA were included in this study. Visual analogue scale (VAS) was used to measure the pain intensity in patients within one year after TKA. The patients were divided into good pain relief group (the improvement of VAS ≥ 3) and poor pain relief group (the improvement of VAS < 3). BMD and other clinical characteristics were also collected. Logistic regression analysis and receiver operating characteristic curve (ROC curve) were used to evaluate the predictive significance of BMD. Subgroup analysis was used to compare the difference of postoperative pain between High BMD group and Low BMD group extra.

RESULTS

34 (21.8%) patients had poor pain relief after TKA. Logistic regression analysis indicated that age, BMD, preoperative hospital for special surgery (HSS) scores, preoperative VAS score and postoperative posterior slope angles (PSA) were the risk factors of poor pain relief (P < 0.05). Using BMD as a predictor, the optimum cut-off value of poor pain relief was T-level = -3.0 SD in the ROC curve, where sensitivity and specificity were 73.5% and 83.7%, respectively. Based on this cut-off value, obvious pain relief was observed in the High BMD group compared with Low BMD group from the 6th month after TKA in the subgroup analysis (P < 0.05).

CONCLUSIONS

BMD is an effective predictor for postoperative pain relief in KOA patients after TKA, and the poor pain relief should be fully considered especially when BMD T-level ≤ -3.0 SD.

Subchondral Trabecular Microstructure and Articular Cartilage Damage Variations Between Osteoarthritis and Osteoporotic Osteoarthritis: A Cross-sectional Cohort Study

Osteoporotic osteoarthritis (OP-OA) is a specific type of OA. In this study, we aimed to assess the subchondral plate and rod microstructural differences between OA and OP-OA patients by using an individual trabeculae segmentation (ITS) system and to analyze the relationships between subchondral microstructures and cartilage damage in OA and OP-OA patients. Overall, 31 femoral heads were included in this study, which included 11 samples with OA and 13 samples with OP-OA; the normal control (NC) group contained 7 healthy femoral heads. ITS was performed to segment the subchondral trabecular bone into plate and rod trabeculae based on microcomputed tomography (micro-CT) images. We compared the plate and rod trabeculae of the subchondral trabecular bone between OA and OP-OA patients. The Osteoarthritis Research Society International (OARSI) score was employed to evaluate cartilage damage based on histological observations. Pearson's correlation coefficient and linear regression analysis were applied to analyze the relationships between subchondral microstructures and articular cartilage damage. Results showed that several microstructural parameters, including bone volume fraction (BV/TV), plate bone volume fraction (pBV/TV), rod bone volume fraction (rBV/TV), plate trabecular number (pTb.N), rod trabecular number (rTb.N), junction density between rod and plate (R-P Junc.D), and junction density between plate and plate (P-P Junc.D), were significantly decreased in patients with OP-OA compared with those in patients with OA (p < 0.05). Histological observations indicated that cartilage damage was more serious in patients with OP-OA than that in patients with OA (p < 0.05). Moreover, BV/TV, pBV/TV, pTb.N, and pTb.Th were significantly related to the OARSI score in both OA and OP-OA patients. These results indicated that there were differences in the subchondral rod and plate trabeculae between OA and OP-OA patients. Subchondral decreased plate trabeculae (pBV/TV, pTb.N, and pTb.Th) might account for cartilage damage in the progression of OP-OA. This study provided new insights to research OA when it is combined with OP.

Bisphosphonates, Old Friends of Bones and New Trends in Clinics

Bisphosphonates, used for a long time in osteoporosis management, are currently the target of intensive research, from pre-formulation studies to more advanced stages of clinical practice. This review presents an overview of the contributions of this family of compounds to human health, starting with the chemistry and clinical uses of bisphosphonates. Following this, their pharmacology is described, highlighting administration-borne handicaps and undesirable effects. The last three sections of the review describe the research efforts that seek to curb delivery-related issues and expand bisphosphonate use. Innovative routes and strategies of administration, such as nano-encapsulation for oral intake or injectable cements for local or in-bone delivery are presented, as well as the latest results of case studies or preclinical studies proposing new therapeutic indications for the clinically approved bisphosphonates. Finally, a selection of anti-infectious bisphosphonate new drug candidates is shown, with focus on the molecules reported in the last two decades.

Osseointegration Pharmacology: A Systematic Mapping Using Artificial Intelligence

Clinical performance of osseointegrated implants could be compromised by the medications taken by patients. The effect of a specific medication on osseointegration can be easily investigated using traditional systematic reviews. However, assessment of all known medications requires the use of evidence mapping methods. These methods allow assessment of complex questions, but they are very resource intensive when done manually. The objective of this study was to develop a machine learning algorithm to automatically map the literature assessing the effect of medications on osseointegration. Datasets of articles classified manually were used to train a machine-learning algorithm based on Support Vector Machines. The algorithm was then validated and used to screen 599,604 articles identified with an extremely sensitive search strategy. The algorithm included 281 relevant articles that described the effect of 31 different drugs on osseointegration. This approach achieved an accuracy of 95%, and compared to manual screening, it reduced the workload by 93%. The systematic mapping revealed that the treatment outcomes of osseointegrated medical devices could be influenced by drugs affecting homeostasis, inflammation, cell proliferation and bone remodeling. The effect of all known medications on the performance of osseointegrated medical devices can be assessed using evidence mappings executed with highly accurate machine learning algorithms.

Analysis of the following Related Surgeries of Unicompartmental Knee Arthroplasty and Total Knee Arthroplasty: A Taiwanese National Health Insurance Research Database Population-Based Study

Background

Current treatment options for both unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are still controversial with no consistent results in which one is superior to others. This is the first study to examine and analyze the following related data available in patients receiving either UKA or TKA from the National Health Research Database (NHIRD) in Taiwan.

Methods

The database was searched from NHIRD, pooling one million random patients. Patients' age, gender, and comorbidities were analyzed in either UKA or TKA between January 2005 and December 2013, or up until death. For the patients that had received bilateral surgeries, further subgrouping was divided into TKA to TKA, UKA to UKA, TKA to UKA, and UKA to TKA to analyze the completion rate curve. Additional analysis of the order codes 64202B, 64053B, and 64198B was defined as failures, and the related failure rate curves were analyzed separately within ten years. Finally, infection-related codes were analyzed.

Results

6,179 patients (n = 276 UKA; n = 5903 TKA) were selected. Age (p < 0.0001) and gender (p = 0.037) had significant differences, with more young population and males having UKA than TKA. Most comorbidities had no significant difference. For the bilateral surgery analysis, the UKA to UKA group had the fastest completion rate (p < 0.001) and UKA to TKA was the slowest. There were no significant differences in the failure rates of 64202B, 64053B, and 64198B.

Conclusion

Most UKA and TKA are appropriate solutions to treat patients with osteoarthritis or osteonecrosis. UKA to UKA is the quickest bilateral completion surgery, and UKA has a higher chance of undergoing revision surgery than TKA.

The relation of oral bisphosphonates to bone marrow lesion volume among women with osteoarthritis

OBJECTIVE

Bone marrow lesions (BMLs) contribute to pain and progression of knee OA. Bisphosphonates may be a potential disease-modifier through amelioration of BMLs. We sought to determine the effect of oral bisphosphonates on BML volume over 12 months.

DESIGN

Women in the Osteoarthritis Initiative who newly initiated an oral bisphosphonate were propensity-score matched to non-initiators. BML volume was assessed using sagittal turbo spin echo fat-suppressed intermediate-weighted MR images at the index date and 12 months later. A validated semi-automated process was used to segment subchondral OA-related BMLs to determine total volume of BMLs based on number of voxels within the outlined area of interest. Mean change in BML volume over 12 months among bisphosphonate initiators was compared with non-initiators using multiple linear regression.

RESULTS

145 bisphosphonate initiators were identified, who were well-matched to their comparators. The difference in mean change in total BML volume between the two groups, regardless of presence of baseline BMLs, was not significant (P = 0.4, 95% CI -156.6 to +354.2). The proportion of participants with decreased, increased, or unchanged BML volumes over the 12 months were similar in both groups. Among those with baseline BMLs, bisphosphonate initiators had a greater proportion with a decrease in BML volume compared with stable or increased BML volume than non-initiators (P = 0.03).

CONCLUSIONS

In this 'real-world' setting of women starting bisphosphonates, we found no clear evidence of benefit on BML volume over a 12-month period, though a trend towards a decrease in BML volume was noted.

Defactinib attenuates osteoarthritis by inhibiting positive feedback loop between H-type vessels and MSCs in subchondral bone

Background

Abnormal bone formation in subchondral bone resulting from uncoupled bone remodeling is considered a central feature in osteoarthritis (OA) pathogenesis. H-type vessels can couple angiogenesis and osteogenesis. We previously revealed that elevated H-type vessels in subchondral bone were correlated with OA and focal adhesion kinase (FAK) in MSCs is critical for H-type vessel formation in osteoporosis. The aim of this study was to explore the correlation between H-type vessels and MSCs in OA pathogenesis through regulation of H-type vessel formation using defactinib (an FAK inhibitor).

Methods

In vivo: 3-month-old male C57BL/6J (WT) mice were randomly divided into three groups: sham controls, vehicle-treated ACLT mice, and defactinib-treated ACLT mice (25 mg/kg, intraperitoneally weekly). In vitro: we explored the role of conditioned medium (CM) of MSCs from subchondral bone of different groups on the angiogenesis of endothelial cells (ECs). Flow cytometry, Western blotting, ELISA, real time (RT)-PCR, immunostaining, CT-based microangiography, and bone micro-CT (μCT) were used to detect changes in relative cells and tissues.

Results

This study demonstrated that inhibition of H-type vessels with defactinib alleviated OA by inhibiting H-type vessel-linked MSCs in subchondral bone. During OA pathogenesis, H-type vessels and MSCs formed a positive feedback loop contributing to abnormal bone formation in subchondral bone. Elevated H-type vessels provided indispensable MSCs for abnormal bone formation in subchondral bone. Flow cytometry and immunostaining results confirmed that the amount of MSCs in subchondral bone was obviously higher in vehicle-treated ACLT mice than that in sham controls and defactinib-treated ACLT mice. In vitro, p-FAK in MSCs from subchondral bone of vehicle-treated ALCT mice increased significantly relative to other groups. Further, the CM from MSCs of vehicle-treated ACLT mice enhanced angiogenesis of ECs through FAK-Grb2-MAPK-linked VEGF expression.

Conclusions

Our results demonstrate that defactinib inhibits OA by suppressing the positive feedback loop between H-type vessels and MSCs in subchondral bone.

The translational potential of this article

Our results provide a mechanistic rationale for the use of defactinib as an effective candidate for OA treatment.

Specific inhibition of FAK signaling attenuates subchondral bone deterioration and articular cartilage degeneration during osteoarthritis pathogenesis

Osteoarthritis (OA), a disease of the entire joint, is characterized by abnormal bone remodeling and coalescent degradation of articular cartilage. We have previously found that elevated levels of H-type vessels in subchondral bone correlate with OA and that focal adhesion kinase (FAK) is critical for H-type vessel formation in osteoporosis. However, the potential role of FAK in OA remains unexplored. Here, we demonstrate that the p-FAK level was dramatically elevated in subchondral bone following anterior cruciate ligament transection (ACLT) in rats. Specific inhibition of FAK signaling with Y15 in subchondral bone resulted in the suppression of subchondral bone deterioration and this effect was mediated by H-type vessel-induced ectopic bone formation. Further, articular cartilage degeneration was also alleviated after Y15 treatment. In vitro, the p-FAK level was significantly elevated in mesenchymal stem cells (MSCs) from vehicle-treated ACLT rats as compared to that in MSCs from sham controls and Y15-treated ACLT rats. Elevated p-FAK level in MSCs promoted vascular endothelial growth factor (VEGF) expression, as demonstrated from the high VEGF level in the blood, subchondral bone, and conditioned medium (CM) of MSCs from vehicle-treated ACLT rats. The CM of MSCs from vehicle-treated ACLT rats might promote the angiogenesis of endothelial cells and the catabolic response of chondrocytes through the FAK-growth factor receptor-bound protein 2-mitogen-activated protein kinase-mediated expression of VEGF. The effect of the CM from MSCs of Y15-treated ACLT rats or that treated with a VEGF-neutralizing antibody on vessel formation and the catabolic response was lowered. Thus, the specific inhibition of FAK signaling may be a promising avenue for the prevention or early treatment of OA.

Effect of Intravenous Zoledronic Acid on Tibiofemoral Cartilage Volume Among Patients With Knee Osteoarthritis With Bone Marrow Lesions: A Randomized Clinical Trial

IMPORTANCE

A proof-of-principle study suggested that intravenous zoledronic acid may reduce knee pain and the size of bone marrow lesions in people with knee osteoarthritis, but data from large trials are lacking.

OBJECTIVE

To determine the effects of intravenous zoledronic acid on knee cartilage volume loss in patients with symptomatic knee osteoarthritis and bone marrow lesions.

DESIGN, SETTING, AND PARTICIPANTS

A 24-month multicenter, double-blind placebo-controlled randomized clinical trial conducted at 4 sites in Australia (1 research center and 3 hospitals). Adults aged 50 years or older with symptomatic knee osteoarthritis and subchondral bone marrow lesions detected by magnetic resonance imaging (MRI) were enrolled from November 2013 through September 2015. The final date of follow-up was October 9, 2017.

INTERVENTIONS

Intravenous infusion with either 5 mg of zoledronic acid in a 100-mL saline solution (n = 113) or a placebo saline solution (n = 110) at baseline and 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was absolute change in tibiofemoral cartilage volume assessed using MRI over 24 months (the minimum clinically important difference [MCID] has not been established). Three prespecified secondary outcomes were change in knee pain assessed by a visual analog scale (0 [no pain] to 100 [unbearable pain]; MCID, 15) and the Western Ontario and McMaster Universities Osteoarthritis Index (0 [no pain] to 500 [unbearable pain]; MCID, 75) over 3, 6, 12, 18, and 24 months and change in bone marrow lesion size over 6 and 24 months (the MCID has not been established).

RESULTS

Of 223 participants enrolled (mean age, 62.0 years [SD, 8.0 years]; 52% were female), 190 (85%) completed the trial. Change in tibiofemoral cartilage volume was not significantly different between the zoledronic acid group and the placebo group over 24 months (-878 mm3 vs -919 mm3; between-group difference, 41 mm3 [95% CI, -79 to 161 mm3]; P = .50). No significant between-group differences were found for any of the prespecified secondary outcomes, including changes in knee pain assessed by a visual analog scale (-11.5 in the zoledronic acid group vs -16.8 in the placebo group; between-group difference, 5.2 [95% CI, -2.3 to 12.8]; P = .17), changes in knee pain assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (-37.5 vs -58.0, respectively; between-group difference, 20.5 [95% CI, -11.2 to 52.2]; P = .21), and changes in bone marrow lesion size (-33 mm2 vs -6 mm2; between-group difference, -27 mm2 [95% CI, -127 to 73 mm2]; P = .60) over 24 months. Adverse events were more common with zoledronic acid than with placebo (96% vs 83%, respectively) and consisted mainly of acute reactions (defined as symptoms within 3 days of administration of infusion; 87% vs 56%).

CONCLUSIONS AND RELEVANCE

Among patients with symptomatic knee osteoarthritis and bone marrow lesions, yearly zoledronic acid infusions, compared with placebo, did not significantly reduce cartilage volume loss over 24 months. These findings do not support the use of zoledronic acid in the treatment of knee osteoarthritis.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12613000039785.

Articular Cartilage Degradation and Aberrant Subchondral Bone Remodeling in Patients with Osteoarthritis and Osteoporosis

Osteoarthritis (OA) and osteoporosis (OP) are two skeletal disorders associated with joint structures. Occasionally, OA and OP occur in the same patient. However, the effect of OP changes on OA progression in patients with osteoporotic OA (OP-OA) has not been reported, especially the potential association between subchondral bone and articular cartilage. Thus we investigated the alterations in the microstructure, biomechanical properties, and remodeling of subchondral bone as well as their association with cartilage damage in the hip joint of patients with OP-OA. Thirty-nine femoral head specimens were obtained from patients who underwent total hip arthroplasty (OA group, n = 19; OP-OA group, n = 20), and healthy specimens from cadaver donors were used (control group, n = 10). The microstructure and biomechanical properties of subchondral bone were evaluated by micro-computed tomography and micro-finite-element analysis. Histology, histomorphometric measurements, and immunohistochemistry were used to assess subchondral bone remodeling and cartilage damage. Linear regression analysis was performed to elucidate the relationship between subchondral bone and articular cartilage. In the subchondral bone of the OP-OA group, compared with that of the OA group, aberrant bone remodeling leads to an inferior microstructure and worsening biomechanical properties, potentially affecting transmission of loading stress from the cartilage to the subchondral bone, and then resulting in accelerated OA progression in patients with OP-OA. The results indicate that changes in subchondral bone could affect OA development and the improvement in subchondral bone with bone-metabolism agents may help mitigate OA progression when OP and OA coexist in the same patients. © 2019 American Society for Bone and Mineral Research.

Unrecognized Osteoporosis Is Common in Patients With a Well-Functioning Total Knee Arthroplasty

BACKGROUND

Peri-prosthetic fractures after total knee arthroplasty (TKA) are associated with poorer outcomes and high costs. We hypothesize that osteoporosis is under-recognized in the TKA population. The purpose of this study is to report osteoporosis prevalence in a healthy cohort of patients with well-functioning TKA and to compare prevalence between males and females.

METHODS

This study is a cross-sectional study of 30 adults (15 males/15 females) aged 59-80 years without known bone health issues who volunteered to undergo routine dual-energy X-ray absorptiometry 2-5 years (average 3.2 ± 0.8) after primary unilateral TKA. These data plus clinical risk factors were used to estimate fracture risk via the Fracture Risk Assessment Tool and skeletal status (normal, osteopenic, osteoporotic) was determined based on the World Health Organization definition. The National Osteoporosis Foundation criteria for treatment were applied to all patients.

RESULTS

Six of 30 (20%) patients had T-score ≤ -2.5. Eighteen of 30 (60%) patients had T-score between -1 and -2.5 and 6 (20%) patients had T-score ≥ -1. Five patients with normal or osteopenic bone mineral density (BMD) had occult vertebral fractures. Eleven of 30 (36.7%) patients met National Osteoporosis Foundation criteria for pharmacologic treatment.

CONCLUSION

The prevalence of occult osteoporosis meeting treatment guidelines after TKA is substantial in this sample (36.7%). BMD and osteoporosis prevalence are similar between men and women. This underappreciated prevalence of osteoporosis may contribute to peri-prosthetic fracture risk. Arthroplasty surgeons and bone health specialists must be aware of post-operative changes in bone density. These data support the further study of post-operative osteoporosis and consideration of routine BMD screening after TKA.

LEVEL OF EVIDENCE

III.

Symptomatic bone marrow lesions induced by reduced bone mineral density in middle-aged women: a cross-sectional Japanese population study

BACKGROUND

The etiology of bone marrow lesions (BMLs) without knee osteoarthritis (KOA) and their association with bone fragility are unclear. We aimed to investigate the association between BMLs, bone mineral density (BMD), and bone markers in women without radiographic evidence of KOA.

METHODS

This single-center cross-sectional study in a Japanese population included 266 women without radiographic evidence of KOA, which was defined as a Kellgren-Lawrence grade < 2. All participants underwent coronal and sagittal T2-weighted fat-suppressed magnetic resonance imaging of their right knee. BML severity was scored according to the Whole-Organ MRI Scoring method. BMD was measured by dual-energy X-ray absorptiometry of the forearm. Levels of bone markers (bone-alkaline phosphatase [BAP], type I procollagen N-terminal propeptide [PINP], cross-linked N-telopeptide of type I collagen [NTx], and tartrate-resistant acid phosphatase-5b [TRACP-5b]), pentosidine, and homocysteine were assessed in the serum. Knee symptoms were evaluated on the basis of the Knee injury and Osteoarthritis and Outcome Score (KOOS). Participants were divided into symptomatic knee and asymptomatic knee groups on the basis of their KOOS according to the classification criteria for early KOA. Multiple linear regression analysis was performed to evaluate the relationship between BMLs, BMD, and bone markers.

RESULTS

The prevalence of BML was 35.3%. Age and some bone marker levels (BAP, PINP, NTx, and TRACP-5b) were higher, and all KOOS subscale scores and BMD were lower in participants with BMLs than in those without BMLs. On multiple linear regression analysis, BMD was negatively associated with BMLs (p = 0.014) in participants with symptomatic knees. There was no such association in participants with asymptomatic knees (p = 0.918). Among the bone markers, BAP (p = 0.006) and PINP (p = 0.043) were positively associated with BMLs in participants with symptomatic knees, while BAP (p = 0.038) and TRACP-5b (p = 0.011) were positively associated with BMLs in participants with asymptomatic knees.

CONCLUSIONS

In symptomatic Japanese women without radiographic evidence of KOA, BMD is negatively associated and some bone markers are positively associated with BMLs after adjustment for age and BMI. Thus, maintaining systemic bone metabolism could contribute to BML prevention in patients with pre-radiographic KOA.

Osteoarthritis year in review 2018: clinical

Osteoarthritis (OA) is the most common joint disease in the world, with an age-associated increase in both incidence and prevalence. Clinical and epidemiologic research is crucial to better understand risk factors for disease, find the best treatments for symptoms, and identify therapies to slow down or even prevent disease progression. This paper is based on a systematic review of the osteoarthritis literature published in English between 2017/05/01 and 2018/04/25, with a focus on papers which have the potential to improve patient care, or which suggest novel areas for future research.

Changes in femoral bone mineral density after total knee arthroplasty: a systematic review and meta-analysis

BACKGROUND

Bone loss after total knee arthroplasty (TKA) may lead to periprosthetic fractures that are associated with significant costs (morbidity, economic, etc.) and pose a challenge to operative fixation. This meta-analysis quantifies the change in bone mineral density (BMD) of the distal femur after primary TKA.

METHODS

A systematic review of six databases was performed by two independent reviewers. Studies that reported bone density after knee arthroplasty were identified and inclusion/exclusion criteria was applied. Data were extracted and analyzed using the Comprehensive Meta-Analysis Software.

RESULTS

Fourteen studies were included in the analysis. The average decrease in BMD was 0.09 [0.05, 0.13], 0.14 [0.08, 0.20], 0.16 [0.10, 0.23], and 0.16 [0.12, 0.20] g/cm² at 3, 6, 12, and 24 months, respectively, corresponding to a 9.3%, 13.2%, 15.8%, and 15.4% BMD loss. A high degree of heterogeneity existed between the studies (I² > 90% at most time points).

CONCLUSION

In summary, there is a rapid and significant 15% decrease in BMD in the first 6 months after TKA that is sustained to 24 months. Better understanding regarding how perioperative optimization of bone health may affect BMD loss and the incidence of periprosthetic fracture is essential.

LEVEL OF EVIDENCE

Therapeutic Level II.

Efficacy of bisphosphonates in specific knee osteoarthritis subpopulations: protocol for an OA Trial Bank systematic review and individual patient data meta-analysis

INTRODUCTION

Randomised clinical trials to date investigating the efficacy of bisphosphonates in knee osteoarthritis (OA) have found divergent results, with a recent meta-analysis finding no superiority of these drugs over placebo. Whether particular patient subgroups are more likely to benefit from this therapy than others is still unclear. We aim to investigate the effects of bisphosphonates compared with a control group (placebo, no treatment, another active treatment) on clinical and structural outcomes in specific knee OA subpopulations with possible distinct rates of subchondral bone turnover.

METHODS AND ANALYSIS

Medline, Embase, Scopus, Web of Sciences and Cochrane Central Register of Controlled Trials will be searched from inception to February 2018. Randomised clinical trials will be eligible if they reported at least one potential treatment effect modifier at baseline: gender, menopausal status, age, body mass index, radiographic stage, knee pain severity, presence of bone marrow lesions, levels of biochemical markers of bone turnover (serum and/or urinary) and systemic bone mineral density status. Authors of original trials will be contacted to obtain individual patient data from each study. Risk of bias will be assessed using the Cochrane Collaboration's tool. The primary outcomes will include pain and radiographic joint space width loss. Studies using other MRI-based assessment of disease progression will also be eligible. Outcomes will be grouped into short-term (≤3 months), intermediate-term (>3 months; ≤12 months) and long-term (>12 months). Regression models will be used, adding an interaction term for each subgroup of interest to determine possible subgroup effects. There was no source of funding for this study.

ETHICS AND DISSEMINATION

Dissemination of our findings is planned to occur through conference presentations, publication in peer-reviewed journals and social media. No formal ethics approval is generally required as no new data collection will be undertaken.

PROSPERO REGISTRATION NUMBER

CRD42018093327.

Disease-modifying drugs in osteoarthritis: current understanding and future therapeutics

INTRODUCTION

Osteoarthritis (OA) is a leading cause of pain and disability among adults with a current prevalence of around 15% and a predicted prevalence of 35% in 2030 for symptomatic OA. It is increasingly recognized as a heterogeneous multi-faceted joint disease with multi-tissue involvement of varying severity. Current therapeutic regimens for OA are only partially effective and often have significant associated toxicities. There are no disease-modifying drugs approved by the regulatory bodies. Areas covered: We reviewed the opportunities within key OA pathogenetic mechanism: cartilage catabolism/anabolism, pathological remodeling of subchondral bone and synovial inflammation to identify targeted disease-modifying osteoarthritis drugs, based on compounds currently in Phase II and III stages of clinical development in which x-ray and/or MRI was used as the structural outcome with/without symptomatic outcomes according to regulatory requirements. Expert opinion: Given the heterogeneity of the OA disease process and complex overlapping among these phenotypes, a 'one size fits all' approach used in most clinical trials would unlikely be practical and equally effective in all patients, as well as in all anatomical OA sites. On the other hand, it is a challenge to develop a targeted drug with high activity, specificity, potency, and bioavailability in the absence of toxicity for long-term use in this chronic disease of predominantly older adults. Further research and insight into evaluation methods for drug-targeted identification of early OA and specific characterization of phenotypes, improvement of methodological designs, and development/refinement of sensitive imaging and biomarkers will help pave the way to the successful discovery of disease-modifying drugs and the optimal administration strategies in clinical practice.

Investigational drugs for the treatment of osteoarthritis, an update on recent developments

INTRODUCTION

Osteoarthritis (OA) is the leading cause of pain, loss of function, and disability among elderly, with the knee the most affected joint. It is a heterogeneous condition characterized by complex and multifactorial etiologies which contribute to the broad variation in symptoms presentation and treatment responses that OA patients present. This poses a challenge for the development of effective treatment on OA.

AREAS COVERED

This review will discuss recent development of agents for the treatment of OA, updating our previous narrative review published in 2015. They include drugs for controlling local and systemic inflammation, regulating articular cartilage, targeting subchondral bone, and relieving pain.

EXPERT OPINION

Although new OA drugs such as monoclonal antibodies have shown marked effects and favorable tolerance, current treatment options for OA remain limited. The authors believe there is no miracle drug that can be used for all OA patients'; treatment and disease stage is crucial for the effectiveness of drugs. Therefore, early diagnosis, phenotyping OA patients and precise therapy would expedite the development of investigational drugs targeting at symptoms and disease progression of OA.

Effects of anti-osteoporosis medications on total hip arthroplasty risks in osteoporotic patients with hip osteoarthritis in Taiwan: a nationwide cohort study

This nationwide cohort study examined the potential disease-modifying effect of anti-osteoporosis medication on hip osteoarthritis. The results revealed that the usage of anti-osteoporosis medication is not associated with decreased risk in undergoing total hip arthroplasty in patient with hip osteoarthritis.

PURPOSE

This study aimed to assess the association between use of anti-osteoporosis medications (AOMs) and the risk of undergoing total hip arthroplasty (THA) in patients with hip osteoarthritis (OA).

METHODS

Using the 2008-2013 National Health Insurance Research Database, we identified patients who were first diagnosed as having hip OA. All identified patients were followed until THA, death of any cause, or December 31, 2013, whichever occurred first. All AOM exposures were divided into three categories: bisphosphonates use, non-bisphosphonates use, and no use of AOMs and assessed in a time-varying manners. The primary outcome was THA. The secondary outcome was the differences in the longitudinal utilization of NSAIDs between AOM users and non-users. Time-dependent Cox proportional hazards models were used to investigate the effect of AOM use on the risk of THA.

RESULTS

We identified 35,870 patients who were first diagnosed as having hip OA and had no history of AOM use between 2009 and 2012. Among them, 3162 and 1667 patients had their first prescription of bisphosphonates and other non-bisphosphonates AOMs during the follow-up period. Mean age of bisphosphonates users, non-bisphosphonates users, and non-users was 75.62, 76.84, and 67.39 years, respectively. Bisphosphonates or non-bisphosphonates users did not show significant change when compared to non-users in terms of risk of undergoing THA [adjusted hazard ratio (aHR) 0.972, 95% confidence interval (CI) 0.743-1.273; aHR 0.926, 95% CI 0.672-1.277].

CONCLUSION

Our results showed that the use of AOMs is not associated with decreased risk of THA in patients with hip OA.

Bisphosphonates for the preservation of periprosthetic bone mineral density after total joint arthroplasty: a meta-analysis of 25 randomized controlled trials

The present meta-analysis aimed to evaluate the long-term efficacy of bisphosphonates (BPs) on preservation of periprosthetic bone mineral density (BMD) after joint arthroplasty. It confirmed the protective effect of BPs in a long-term follow-up, and found the influence factors on this effect.

INTRODUCTION

Periprosthetic bone loss is believed to cause aseptic loosening and failed prosthetic fixation in joint arthroplasty. This meta-analysis which included high-quality randomized controlled trials aimed to analyze the effect of bisphosphonates on maintaining periprosthetic bone mineral density after total joint arthroplasty.

METHODS

Twenty-five RCTs were included and the total number of participants was 1163 by computerized searches of bibliographic databases. The weighted mean differences with 95% confidence interval were calculated to evaluate the efficacy of BPs on total periprosthetic BMD and the BMD of different Gruen zones. Subgroup analyses identified the potentially influencing factors such as surgical site, cement fixation, and generation of BPs. A descriptive review was conducted for BP-related adverse effects.

RESULTS

The BPs group presented significantly higher total periprosthetic BMD in the BPs group than that in the control group at 3, 6, 12 months, 2-4 years, and 5-10 years after arthroplasty (P < 0.05). The BPs group presented significantly higher periprosthetic BMD in femoral Gruen Zone 1 and 7 than that in the control group at 3, 6, 12 months, 2-4 years, and 5-10 years (P < 0.05). The heterogeneity was minimized by dividing THA and TKA into two subgroups. Subgroup analyses revealed that the effect of BPs on preservation of BMD was significantly greater in arthroplasty with cemented component than in that with uncemented component at 12 months and 5-10 years (P < 0.05), and the administration of the second and third generation BPs was significantly more effective than the first-generation BPs at 6 and 12 months (P < 0.05). None of the included studies described severe or fatal adverse effects related to BPs.

CONCLUSIONS

BPs have significantly long-term efficacy on the preservation of periprosthetic BMD after joint arthroplasty. To obtain a better efficacy, the cemented components and the second and third generation BPs are recommended.

Effect of bisphosphonates on periprosthetic bone loss after total knee arthroplasty: a meta-analysis of randomized controlled trials

Background

Aseptic loosening and osteolysis are the most common indications after TKA for revision surgery. This meta-analysis which included high-quality randomized controlled trials (RCTs) aimed to analyze the effect of bisphosphonates (BPs) on maintaining periprosthetic bone mineral density (BMD) after total knee arthroplasty.

Methods

PubMed, AMED, EMBASE, the Cochrane library, ISI Web of Science, and China National Knowledge Infrastructure were systematically searched, five RCTs were included and the total number of participants was 188. The weighted mean differences with 95% confidence interval were calculated to evaluate the efficacy of BPs on total BMD of knee and the BMD of different periprosthetic regions. A descriptive review was performed for BP-related adverse effects.

Results

The BPs group presented significantly higher total BMD in proximal part of the tibia than the control group at 3 and 6 months (P < 0.05), but no significant difference at 12 months (P = 0.09). The BPs group presented significantly higher BMD in the distal aspect of the femur than that in the control group at 3, 6, 12 months. The BPs group presented significantly higher periprosthetic BMD than that in the control group at 3, 6 and 12 months in tibial medial and lateral metaphyseal region, and femoral anterior, central and posterior metaphyseal region (p < 0.05), but no significant difference for tibial diaphyseal region at 3, 6, and 12 months. None of the included studies described severe or fatal adverse effects related to BPs.

Conclusion

BPs have a short-term effect on reducing periprosthetic bone loss after total knee arthroplasty. Compared with diaphyseal region, BPs are more effective on the preservation of BMD in medial lateral metaphyseal regions of proximal tibia and in anterior, central, and posterior metaphyseal region of distal femur.