Total Joint Arthroplasty and Osteoporosis: Looking Beyond the Joint to Bone Health

The effect of fixation type on periprosthetic fractures in high-risk patients who have osteoporosis undergoing total joint arthroplasty

Introduction

Minimizing the burden of periprosthetic fractures (PFF) following total joint arthroplasty (TJA) with regard to morbidity and mortality remains an outcome of interest. Patient and surgical risk factors, including osteoporosis and fixation type, have not truly been optimized in patients undergoing TJA as a means to reduce the risk of PFF. As such, we examined: (1) What percentage of patients who underwent THA and total knee arthroplasty (TKA) met the criteria for osteoporosis screening? (2) How did the 5-year rate of PFF and fragility fracture differ in the high-risk and low-risk groups for osteoporosis between the cemented and cementless cohorts? (3) What percentage of the aforementioned patients received a dual x-ray absorptiometry (DEXA) scan before THA or TKA?

Methods

We queried an all-payer, national database from April 1, 2016 to December 31, 2021, to identify high-risk and low-risk patients who underwent TJA with a cementless or cemented fixation. High-risk patients met at least one of the following criteria: men at least 70 years old, women at least 65 years old, or patients at least 60 years old who have the following: tobacco use, alcohol abuse, body mass index <18.5, prior fragility fracture, chronic systemic corticosteroids, or genetic condition affecting sex hormones or bone mineral density. Exclusion criteria were a diagnosis of malignancy, high-energy events (motor vehicle collision), those who underwent TJA indicated for fracture, patients less than 50 years old, those who had a prior diagnosis of or treatment for osteoporosis, and a minimum follow-up of less than 2 years.

Results

There were 384,783 patients (67.1 %) who underwent cementless TKA and 67,774 patients (11.8 %) who underwent cementless TKA who were considered high risk. Additionally, there were 62,505 patients (10.9 %) who underwent cemented THA and 58,667 patients (10.2 %) who underwent cementless THA and were considered high risk. The cementless cohort had a 5-year periprosthetic fracture risk following TKA of 7.8 % (95 % CI, 5.56 to 10.98) in comparison to 4.30 % in the cemented cohort (85 % CI, 3.98 to 4.65), P < 0.0001. The high-risk cementless cohort had a 5-year periprosthetic fracture risk following THA of 7.9 % (95 % confidence interval (CI), 6.87 to 9.19) in comparison to 7.78 % in the cemented cohort (85 % CI, 6.77 to 8.94), P < 0.0001.

Conclusion

There is an increased risk of PFF at 5 years following TKA in patients at high risk for osteoporosis undergoing cementless fixation in comparison to cemented fixation. There is an increased risk of PFF at 5 years following THA in patients at high risk for osteoporosis for both cementless fixation and cemented fixation, but no clinically meaningful difference between the two groups. Addressing the shortcomings of the underutilization of bone density scans and better selecting appropriate patients for TJA based on bone quality and fracture risk can help expedite the process of improving the current state of practice.

Prior Fragility Fractures are Associated With a Higher Risk of Bone Health-Related Complications Within Eight Years Following Lumbar Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

To determine the 8-year risk of revision lumbar fusion, pseudoarthrosis, mechanical failure, fragility fracture, and vertebral compression fracture in patients with a prior fragility fracture compared with those without.

SUMMARY OF BACKGROUND DATA

Osteoporosis is a known modifiable risk factor for revision following lumbar fusion due to inadequate fixation. Patients with prior fragility fractures have been shown to have increased bone health-related complications following various orthopedic surgeries; however, there is a paucity of literature that identifies these complications in patients undergoing lumbar fusion.

PATIENTS AND METHODS

Patients aged 50 years and older who underwent elective lumbar fusion were identified in a large national database and stratified based on whether they sustained a fragility fracture within three years prior to fusion. These patients were propensity-score matched to a control based on age, gender, and Charlson the comorbidity index using a 1:1 ratio. Kaplan-Meier and Cox proportional hazards analyses were used to observe the cumulative incidences and risk of complications within eight years of index surgery.

RESULTS

After matching, 8805 patients were included in both cohorts. Patients who sustained a prior fragility fracture had a higher risk of revision [hazard ratio (HR): 1.46; 95% CI: 1.26-1.69; P <0.001), pseudoarthrosis (HR: 1.31; 95% CI: 1.17-1.48; P <0.001), mechanical failure (HR: 2.08; 95% CI: 1.78-2.45; P <0.001), secondary fragility fracture (HR: 6.36; 95% CI: 5.86-6.90; P <0.001), and vertebral compression fracture (HR: 7.47; 95% CI: 7.68-8.21; P <0.001) when compared with the control cohort.

CONCLUSION

Patients who sustain a fragility fracture prior to lumbar fusion have an increased risk of revision, pseudoarthrosis, and mechanical failure within eight years. Surgeons should be aware of this high-risk patient population and consider bone health screening and treatment to reduce these preventable complications.

Patients with Periprosthetic Femoral Hip Fractures are Commonly Classified as Having Osteoporosis Based on DXA Measurements

Periprosthetic femoral hip fractures are subject to an increasing incidence and are often considered to be related to osteoporosis. However, there are no available studies that have determined the frequency of osteoporosis in affected patients using gold standard dual-energy X-ray absorptiometry (DXA). In this retrospective comparative study, we analyzed the DXA results of 40 patients with periprosthetic femoral hip fractures who were treated surgically in our department. DXA measurements were performed at the total hip and the lumbar spine to determine bone mineral density T-scores. Data were compared to two age-, sex-, and BMI-matched control groups in which patients underwent DXA prior to aseptic revision surgery for other causes or primary THA (consisting of 40 patients each). The mean T-score in the periprosthetic fracture cohort was significantly lower (- 1.78 ± 1.78) than that of the aseptic revision (- 0.65 ± 1.58, mean difference - 1.13 [95% CI - 1.88 to - 0.37]; p = 0.001) and the primary THA cohort (- 0.77 ± 1.34, mean difference - 1.01 [95% CI - 1.77 to - 0.26]; p = 0.005). Accordingly, osteoporosis was detected more frequently (45%) in the fracture cohort compared to patients undergoing aseptic revision (12.5%) and primary THA (10%). In conclusion, almost half of the patients with periprosthetic femoral hip fractures have osteoporosis according to DXA measurements. A regular assessment of bone health in THA enables identification of patients with osteoporosis who likely benefit from initiation of osteoporosis medication and cemented stem fixation.

Assessing osteoporosis screening compliance in total joint surgery: a retrospective chart review

CONTEXT

Osteoporosis is a prevalent concern, particularly among aging populations, leading to increased risk of fractures, including those related to hip and knee arthroplasty procedures. Screening for osteoporosis, especially with dual X-ray absorptiometry (DXA) scans, is crucial for early detection and management.

OBJECTIVES

This study aimed to assess adherence to osteoporosis screening guidelines among patients aged 65 and older undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) within a single health network. Factors influencing screening adherence were also explored.

METHODS

A retrospective chart review of 2,160 patients undergoing elective THA or TKA between January 2019 and January 2023 was conducted. Demographic data, osteoporosis screening status, and occurrence of periprosthetic fractures were analyzed. Statistical analysis included descriptive statistics and chi-square tests.

RESULTS

Only 24.1 % of eligible patients underwent a DXA scan prior to surgery. Females were more likely to undergo screening than males, and race was also associated with screening status. A total of 45 periprosthetic fractures were identified, with no significant correlation between osteoporosis status, DXA screening, and fracture occurrence.

CONCLUSIONS

Adherence to osteoporosis screening guidelines among geriatric patients undergoing elective total joint arthroplasty remains low within the studied health network. Despite the lack of correlation between screening and fracture occurrence in this study, the importance of screening and potential optimization in high-risk patients is emphasized. Further research is needed to assess outcomes associated with different care pathways in bone health screening and management for elective geriatric total joint patients.

Prevalence and Clinical Impact of Sarcopenia in Patients Undergoing Total Joint Arthroplasty: A Systematic Review and a Meta-Analysis

BACKGROUND

Sarcopenia is a progressive loss of skeletal muscle mass and function. It is associated with adverse outcomes after several orthopaedic procedures. However, its role in total joint arthroplasty (TJA) is not fully explored. Therefore, we wanted to conduct a systematic review and meta-analysis to answer the following questions: (1) What is the prevalence of sarcopenia in patients undergoing TJA?; (2) What factors are associated with the prevalence of sarcopenia in patients undergoing TJA?; What is the impact of sarcopenia on medical outcomes following TJA?; and (4) What is the impact of sarcopenia on surgical outcomes following TJA?

METHODS

Electronic databases PubMed, Scopus, Cochrane, and Google Scholar were searched. The data were pooled using the random-effects model and graphically represented by a forest plot. We included a total of 13 studies, evaluating 399,097 patients.

RESULTS

The pooled prevalence of sarcopenia was 20.1% (95% confidence interval [CI] 13.6 to 28.8%; P < .00001; I2 = 94.7%) in total knee arthroplasty (TKA) and 5.2% (95% CI 0.1 to 69.7%; P = .128; I2 = 99.6%) in total hip arthroplasty (THA). Meta-regression found no links between age, sex, body mass index, diabetes, obesity, arthroplasty type, and sarcopenia prevalence in TJA. Sarcopenia increased risk of blood transfusion (odds ratio [OR] 4.68 [95% CI 3.51 to 6.25]; P < .00001), pneumonia (OR 1.94 [95% CI 1.14 to 3.30]; P = .01), urinary tract infection (UTI) (OR 1.64 [95% CI 1.31 to 2.05]; P < .001), prosthetic fracture (OR 2.12 [95% CI 1.51 to 2.98]; P < .0001), prosthetic dislocation (OR 1.99 [95% CI 1.62 to 2.44]; P < .00001), and mechanical loosening (OR 1.78 [95% CI 1.43 to 2.22]; P < .00001) in TKA. Sarcopenic patients were at an increased risk of UTI (OR 1.79 [95% CI 1.32 to 2.43]; P = .0002) and prosthetic loosening (OR 1.97 [95% CI 1.10 to 3.53]; P = .02) post-THA.

CONCLUSIONS

Baseline sarcopenia was prevalent in patients undergoing TJA. It was associated with an increased risk of UTI and prosthetic loosening following TKA and THA. Increased risk of blood transfusion, pneumonia, prosthetic fractures, and mechanical loosening following TKA.

Systemic Osteoporosis and Osteopenia Among Periprosthetic Fractures After Total Hip Arthroplasty

BACKGROUND

Most periprosthetic fractures following total hip arthroplasty (THA) are fragility fractures that qualify patients for osteoporosis diagnoses. However, it remains unknown how many patients were diagnosed who had osteoporosis before injury or received the proper evaluation, diagnosis, and treatment after injury.

METHODS

We identified 171 Vancouver B2 (109) and B3 (62) periprosthetic femur fractures treated with a modular fluted tapered stem from 2000 to 2018 at 1 institution. The mean patient age was 75 years (range, 35 to 94), 50% were women, and the mean body mass index was 29 (range, 17 to 60). We identified patients who had osteoporosis or osteopenia diagnoses, a fracture risk assessment tool (FRAX), bone mineral density (BMD) testing, an endocrinology consult, and osteoporosis medications. Age-appropriate BMD testing was defined as no later than 1 year after the recommended ages of 65 (women) or 70 years (men). The mean follow-up was 11 years (range, 4 to 21).

RESULTS

Falls from standing height caused 94% of fractures and thus, by definition, qualified as osteoporosis-defining events. The prevalence of osteoporosis diagnosis increased from 20% before periprosthetic fracture to 39% after (P < .001). The prevalence of osteopenia diagnosis increased from 13% before the fracture to 24% after (P < .001). The prevalence of either diagnosis increased from 24% before fracture to 44% after (P < .001). No patients had documented FRAX scores before fracture, and only 2% had scores after. The prevalence of BMD testing was 21% before fracture and 22% after (P = .88). By the end of the final follow-up, only 16% had received age-appropriate BMD testing. The proportion of patients who had endocrinology consults increased from 6% before the fracture to 25% after (P < .001). The proportion on bisphosphonate therapy was 19% before fracture and 25% after (P = .08).

CONCLUSIONS

Although most periprosthetic fractures following THA are fragility fractures that qualify patients for osteoporosis diagnoses, there remain major gaps in diagnosis, screening, endocrinology follow-up, and treatment. Like nonarthroplasty fragility fractures, a systematic approach is needed after periprosthetic fractures.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Chronic Oral Corticosteroid Use and 10-Year Incidence of Major Complications Following Total Knee Arthroplasty

BACKGROUND

Oral corticosteroids are the primary treatment for several autoimmune conditions. The risk of long-term implant, bone health, and infectious-related complications in patients taking chronic oral corticosteroids before total knee arthroplasty (TKA) is unknown. We compared the 10-year cumulative incidence of revision, periprosthetic joint infection (PJI), fragility fracture (FF), and periprosthetic fracture following TKA in patients who had and did not have preoperative chronic oral corticosteroid use.

METHODS

A retrospective cohort analysis was conducted using a national database. Primary TKA patients who had chronic preoperative oral corticosteroid use were identified using Current Procedural Terminology and International Classification of Disease 9 and 10 codes. Exclusion criteria included malignancy, osteoporosis treatment, trauma, and < 2-year follow-up. Primary outcomes were 10-year cumulative incidence and hazard ratios (HRs) of all-cause revision (ACR), aseptic revision, PJI, FF, and periprosthetic fracture. A Kaplan-Meier analysis and a multivariable Cox proportional hazards model were utilized. Overall, 611,596 patients were identified, and 5,217 (0.85%) were prescribed chronic corticosteroids. There were 10,000 control patients randomly sampled for analysis.

RESULTS

Corticosteroid patients had significantly higher 10-year HR of FF (HR; 95% confidence interval); P value (1.47; 1.34 to 1.62; P < .001)], ACR (1.21; 1.05 to 1.40; P = .009), and PJI (1.30; 1.01 to 1.69; P = .045) when compared to the control.

CONCLUSIONS

Patients prescribed preoperative chronic oral corticosteroids had higher risks of ACR, PJI, and FF within 10 years following TKA compared to patients not taking corticosteroids. This information can be used by surgeons during preoperative counseling to educate this high-risk patient population about their increased risk of postoperative complications.

Osteoporosis and Total Knee Arthroplasty: Higher 5-Year Implant-Related Complications

BACKGROUND

The risk of revision surgery in patients who have osteoporosis after total knee arthroplasty (TKA) is understudied. Our aim was to compare the 5-year cumulative risk of revision surgery after TKA in patients who have preoperative osteoporosis.

METHODS

A national administrative claims database was queried for patients undergoing primary TKA from 2010 to 2021. There were 418,054 patients included, and 41,760 (10%) had osteoporosis. The 5-year incidence of revision surgery was examined for all-causes, periprosthetic fracture (PPF), aseptic loosening, and periprosthetic joint infection (PJI). A multivariable analysis was conducted using Cox proportional hazards models. Hazards ratios (HRs) were reported with 95% confidence intervals (CIs).

RESULTS

The 5-year rate of all-cause revision surgery was higher for patients who had osteoporosis (HR 1.1, 95% CI: 1.0 to 1.2), however, the highest risk of revision surgery was seen for PPF (HR 1.8, 95% CI: 1.6 to 2.1). Patients who had osteoporosis also had elevated risk of revision surgery for PJI (HR 1.2, 95% CI: 1.1 to 1.3) and aseptic loosening (HR 1.2, 95% CI: 1.1 to 1.3). Osteoporosis was independently associated with PJI and aseptic loosening at a higher rate in obese patients.

CONCLUSIONS

In unadjusted survival analysis, those who had osteoporosis have a marginally lower risk of all-cause revision surgery. However, after controlling for age, sex and comorbidities, patients who had osteoporosis have a nearly 2-fold increased risk of 5-year revision for PPF after TKA, and mildly increased risk of revision for all causes, aseptic loosening, and PJI. Obesity may also modulate this association. Future studies should determine the extent to which treatment of osteoporosis modifies these postoperative outcomes.

Skeletal Status in Patients Scheduled for Elective Lumbar Spine Surgery: Comparison of Discectomy, Decompression, Fusion, and Revision

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

To investigate and compare the prevalence of low bone mineral density (BMD) and abnormal laboratory bone metabolism parameters in patients undergoing elective primary discectomy, decompression, and fusion and to outline possible differences in these parameters between patients undergoing revision for skeletal vs non-skeletal complications.

METHODS

We retrospectively evaluated BMD measurements by dual-energy x-ray absorptiometry (DXA) in 389 consecutive patients scheduled for elective lumbar spine surgery. Next to demographic characteristics, laboratory bone metabolism parameters were assessed. Group comparisons were performed between primary discectomy, decompression, and fusion. In patients scheduled for revision surgery after fusion, potential differences in the skeletal status between those with skeletal vs non-skeletal complications were analyzed.

RESULTS

Osteoporosis by T-score was detected in 6.7%, 11.0% and 14.7% of the patients undergoing discectomy, decompression and fusion, respectively. While vitamin D deficiency (67.6%) and hyperparathyroidism (16.4%) were frequently detected, no differences in laboratory bone metabolism markers could be found between the groups. Female sex (P<.001), higher age (P=.01) and lower BMI (P<.001) were associated with lower BMD. In the cohort of patients undergoing revision surgery due to complications after fusion, those with skeletal complications did not differ in BMD or bone metabolism from those with non-skeletal complications.

CONCLUSIONS

Osteoporosis represents a relevant comorbidity in patients scheduled for elective spine surgery, which is why DXA should be routinely performed in these patients. However, DXA may provide limited information in identifying patients at increased risk for skeletal complications after fusion.

Radiographic Assessment of Bone Quality Using 4 Radiographic Indexes: Canal Diaphysis Ratio Is Superior

BACKGROUND

Osteoporosis increases the risk of periprosthetic fracture and loosening in hip arthroplasty. Many methods have been proposed to assess bone quality in X-rays, including both qualitative such as the Dorr classification and quantitative such as the Calcar-Canal Ratio (CCR) and Cortical-Thickness index/Canal-Bone ratio (CTI/CBR). The Canal-Diaphysis ratio (CDR) has been described as a predictor for hip fragility fractures; however, its relationship with bone mineral density (BMD) has not been described. The purpose of this study was to evaluate the correlation of the Dorr classification, CCR, CTI/CBR, and CDR with BMD of the proximal femur in patients without hip fracture.

METHODS

Forty-seven patients over 45 years of age who had less than 6 months between radiographs and dual-energy X-ray absorptiometry were evaluated. Measurements of CCR, CBR, CDR, and Dorr classification were performed in all radiographs by 2 independent observers.

RESULTS

The CDR had a high correlation (r = 0.74, P=<0.01) with BMD, whereas the CTI/CBR had a moderate correlation (r = 0.49, P=<0.01), and the CCR had no correlation with BMD (r = 0.06, P = .96). When evaluating the receiver operating characteristic curve, CDR showed the best performance (area under curve [AUC] = 0.75) followed by CBR (AUC = 0.73) and CCR (AUC = 0.61). The optimal cutoff value for the CDR was 0.49, with 100% sensitivity and 58% specificity. The inter- and intra-observer variability was good for all methods. No differences were found between Dorr classification of patients who had or did not have osteoporosis.

CONCLUSION

Of all the analyzed methods, the CDR was found to have the best correlation with BMD. This study proposes the use of CDR as a tool for assessing bone quality when deciding the implant fixation method in hip arthroplasty.

Bisphosphonate Use May be Associated With an Increased Risk of Periprosthetic Hip Fracture

BACKGROUND

Osteoporosis is common among patients undergoing primary total hip arthroplasty (THA). This study aimed to evaluate the effect of bisphosphonate treatment on osteoporotic patients undergoing primary THA.

METHODS

Using a national database, 30,137 patients who had osteoporosis before primary elective THA were identified during 2010 to 2020. Patients undergoing nonelective THA and those using corticosteroids or other medications for osteoporosis were excluded. Bisphosphonate users and bisphosphonate naïve patients were matched 1:1 based on age, sex, Elixhauser comorbidity index, and a history of obesity, rheumatoid arthritis, tobacco use, and alcohol abuse. Kaplan-Meier and multivariate analyses were used to compare 2-year outcomes between groups.

RESULTS

Among matched cohorts of 9,844 patients undergoing primary THA, bisphosphonate use was associated with a significantly higher 2-year rate of periprosthetic fracture (odds ratio 1.29, 95% confidence interval 1.04 to 1.61, P = .022). There was a trend toward increased risk of any revision with bisphosphonate use (odds ratio 1.19, confidence interval 1.00 to 1.41, P = .056). Rates of infection, aseptic loosening, dislocation, and mortality were not statistically different between bisphosphonate users and bisphosphonate-naïve patients.

CONCLUSION

In osteoporotic patients, bisphosphonate use before primary THA is an independent risk factor for periprosthetic fracture. Additional longer-term data are needed to determine the underlying mechanism for this association and identify preventative measures.

CB2 regulates oxidative stress and osteoclastogenesis through NOX1-dependent signaling pathway in titanium particle-induced osteolysis

Periprosthetic osteolysis (PPO) induced by wear particles at the interface between the prosthesis and bone is a crucial issue of periprosthetic bone loss and implant failure. After wear and tear, granular material accumulates around the joint prosthesis, causing a chronic inflammatory response, progressive osteoclast activation and eventual loosening of the prosthesis. Although many studies have been conducted to address bone loss after joint replacement surgeries, they have not fully addressed these issues. Focusing on osteoclast activation induced by particles has important theoretical implications. Cannabinoid type II receptor (CB2) is a seven-transmembrane receptor that is predominantly distributed in the human immune system and has been revealed to be highly expressed in bone-associated cells. Previous studies have shown that modulation of CB2 has a positive effect on bone metabolism. However, the exact mechanism has not yet been elucidated. In our experiments, we found that NOX1-mediated ROS accumulation was involved in titanium particle-stimulated osteoclast differentiation. Furthermore, we confirmed that CB2 blockade alleviated titanium particle-stimulated osteoclast activation by inhibiting the NOX1-mediated oxidative stress pathway. In animal experiments, downregulation of CB2 alleviated the occurrence of titanium particle-induced cranial osteolysis by inhibiting osteoclasts and scavenging intracellular ROS. Collectively, our results suggest that CB2 blockade may be an attractive and promising therapeutic scheme for particle-stimulated osteoclast differentiation and preventing PPO.

Team Approach: Bone Health Optimization in Orthopaedic Surgery

» Bone health optimization (BHO) has become an increasingly important consideration in orthopaedic surgery because deterioration of bone tissue and low bone density are associated with poor outcomes after orthopaedic surgeries.» Management of patients with compromised bone health requires numerous healthcare professionals including orthopaedic surgeons, primary care physicians, nutritionists, and metabolic bone specialists in endocrinology, rheumatology, or obstetrics and gynecology. Therefore, achieving optimal bone health before orthopaedic surgery necessitates a collaborative and synchronized effort among healthcare professionals.» Patients with poor bone health are often asymptomatic and may present to the orthopaedic surgeon for reasons other than poor bone health. Therefore, it is imperative to recognize risk factors such as old age, female sex, and low body mass index, which predispose to decreased bone density.» Workup of suspected poor bone health entails bone density evaluation. For patients without dual-energy x-ray absorptiometry (DXA) scan results within the past 2 years, perform DXA scan in all women aged 65 years and older, all men aged 70 years and older, and women younger than 65 years or men younger than 70 years with concurrent risk factors for poor bone health. All women and men presenting with a fracture secondary to low-energy trauma should receive DXA scan and bone health workup; for fractures secondary to high-energy trauma, perform DXA scan and further workup in women aged 65 years and older and men aged 70 years and older.» Failure to recognize and treat poor bone health can result in poor surgical outcomes including implant failure, periprosthetic infection, and nonunion after fracture fixation. However, collaborative healthcare teams can create personalized care plans involving nutritional supplements, antiresorptive or anabolic treatment, and weight-bearing exercise programs, resulting in BHO before surgery. Ultimately, this coordinated approach can enhance the success rate of surgical interventions, minimize complications, and improve patients' overall quality of life.

The Association of Prior Fragility Fractures on 8-Year Periprosthetic Fracture Risk Following Total Hip Arthroplasty

BACKGROUND

Fragility fractures are often the initial clinical presentation of osteoporosis. Patients who have a history of fragility fractures undergoing total hip arthroplasty (THA) have an increased risk of 2-year postoperative complications. However, the association of recent fragility fractures with complications beyond 2 years following THA remains unknown. The purpose of this study was to characterize the association of prior fragility fractures with 8-year risks of revision THA, periprosthetic fracture (PPF), and secondary fragility fracture.

METHODS

Patients aged 50 years and more who underwent THA for osteoarthritis were identified in a large national database. Patients were stratified based on whether they sustained a fragility fracture within 3 years prior to THA. There were 18,529 patients who had a prior fragility fracture and 408,753 who did not have a prior fragility fracture. Demographics and comorbidities were collected. Kaplan-Meier and Cox Proportional Hazards analyses were used to observe the cumulative incidences of all-cause revision, PPF, and secondary fragility fracture within 8 years of index surgery.

RESULTS

Patients who had recent fragility fracture had significantly higher risks of revision THA (Hazard Ratio [HR] 1.7; P < .001), PPF (HR 2.2; P < .001), and secondary fragility fracture (HR 4.9; P < .001).

CONCLUSION

Prior fragility fracture was shown to be a significant risk factor for revision THA, PPF, and secondary fragility fracture within 8 years of THA. Identification of these high-risk patients with an emphasis on preoperative and postoperative bone health optimization may help minimize these complications.

Fracture Risk Assessment Tool Scores and Radiographical Bone Measurements in Total Hip Arthroplasty Patients

BACKGROUND

Osteoporosis is a major risk factor for periprosthetic fractures (PPFx) in total hip arthroplasty (THA) patients but is not routinely screened for in this population. Given the availability of hip x-rays and preoperative screenings, Fracture Risk Assessment Tool (FRAX) scores and radiographic bone measurements are potentially promising, novel risk stratification tools. This study aims to characterize FRAX scores and radiographic bone measurements in THA and PPFx patients.

METHODS

A retrospective chart review for demographic variables and FRAX scores was performed on 250 THA and 40 PPFx patients. Radiographic bone measurements including cortical thicknesses (both antero-posterior [AP] and lateral), canal to calcar ratio, canal flare index, and Dorr classifications were obtained from preoperative x-rays. Correlation between FRAX scores and radiographic bone measurements was investigated with linear regressions. FRAX scores and radiographic bone measurements were compared between the THA and PPFx patients. Multivariate logistic regressions were used to identify factors predicting PPFx.

RESULTS

FRAX scores were significantly correlated with both AP (P < .001) and lateral (P = .007) cortical thicknesses. Compared to THA patients, those with PPFx had significantly higher FRAX scores (P = .003) and lower AP cortical thickness (P = .005). Multivariate logistic regressions demonstrated that FRAX major osteoporotic fracture risk score and AP cortical thickness were independent predictors of PPFx (P = .001 and .024, respectively).

CONCLUSION

Cortical thicknesses are good proxy measurements of osteoporosis-related fracture risk in THA patients. In addition, both major and AP cortical thickness indices are promising tools for identifying patients who are at a high risk of PPFx in the THA population.