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

Periprosthetic fractures are osteoporotic fractures: missed opportunities for osteoporosis diagnosis

Joint replacement surgery is common in older adults, leading to increasing periprosthetic fracture (PPFx) occurrence. We reviewed all PPFx seen over a 4-year period at an academic hospital. Clinical osteoporosis could be diagnosed based on existing data in 104 (67%) at the time of PPFx. Periprosthetic fractures are generally osteoporosis-related.

PURPOSE

Periprosthetic fractures (PPFx) cause morbidity, mortality, and cost. This study's purpose was to describe osteoporosis-related data available at the time of PPFx.

METHODS

The electronic medical record (EMR) of PPFx patients seen over 4 years in a university orthopedic practice were reviewed. Demographic data and osteoporosis relevant parameters were collected. Prior DXA studies were reviewed, and L1 Hounsfield unit (HU) measurements were performed on CT scans obtained within 2 years before PPFx. Clinical osteoporosis was defined as prior diagnosis, prescribed osteoporosis treatment, T-score ≤  - 2.5, HU ≤ 100, or prior fracture.

RESULTS

Records of 156 PPFx patients (115 F/41 M), mean (SD) age 75.4 (11.9), were reviewed. Almost all 153/156 (98%) of these fractures were femoral. Falls caused 139 (89%); 12 (8%) were spontaneous. Mean time post-arthroplasty was 7.9 (6.3) years. Prior fragility fracture(s) occurred in 72 (46%); 14 were PPFx. Osteoporosis was previously diagnosed in 45 (29%) and medications prescribed in 41 (26%). Prior to PPFx, DXA data were available in 62, mean (SD) lowest T-score was - 1.9 (0.9) and was ≤  - 2.5 in 19. CT data were available in 46; mean (SD) L1 HU was 79.0 (29.4) and was ≤ 100 in 35. Based on existing data, clinical osteoporosis could have been diagnosed in 104 (67%) at the time of PPFx.

CONCLUSION

Periprosthetic fractures are osteoporosis-related. They occur in older adults, often female, and result from falls; BMD, when assessed, is low. Data available at the time of PPFx often allows osteoporosis diagnosis; this should prompt evaluation and pharmacologic treatment consideration.

Total knee arthroplasty and periprosthetic distal femoral fracture: looking beyond the osteoporosis to previous osteoporotic fracture

Osteoporosis increases the risk of periprosthetic distal femoral fractures after TKA, especially in patients with a history of osteoporotic fractures. Therefore, careful assessment and proper treatment of osteoporosis need and the importance of taking osteoporotic medication needs to be recognized by the patients following primary TKA.

PURPOSE

Osteoporosis is a risk factor for fractures, including those of the hip, vertebrae, and distal radius; however, the association between osteoporosis and periprosthetic fractures after total knee arthroplasty (TKA) has not been much investigated. Therefore, we aimed to investigate the association of the presence of systemic osteoporosis with periprosthetic fractures after TKA.

METHODS

This study included 34 patients with periprosthetic fractures following primary TKA and 106 controls matched for age and sex. Bone mineral density was evaluated at the femoral neck, total hip, and lumbar spine using dual X-ray absorptiometry. Medical records were reviewed for age; sex; body mass index; smoking; rheumatoid arthritis, endocrine diseases, and cardiovascular diseases; history of glucocorticoid use; medication for osteoporosis; and history of previous osteoporotic fracture. In addition, anterior femoral notching after TKA was evaluated. Univariable and multivariable logistic regression analysis were used to determine factors associated with periprosthetic fracture.

RESULTS

The prevalence of osteoporosis in the fracture group was higher than that in the control group (61.8% vs. 40.6%, p=0.045). The rate of medication for osteoporosis was significantly low in the fracture group (47.6 % vs 76.7%, p=0.026). History of previous osteoporotic fracture (odds ratio [OR], 9.1; p=0.015) and osteoporosis (OR, 3.6; p=0.013) were significant risk factors for periprosthetic fractures after TKA. Medication for osteoporosis could decrease the risk of periprosthetic fracture (OR 0.3; p=0.020).

CONCLUSION

Osteoporosis is a major risk factor for periprosthetic distal femoral fractures after TKA. Therefore, careful assessment and proper treatment of osteoporosis need and the importance of taking osteoporotic medication needs to be recognized to the patients following primary TKA, especially in patients with a history of osteoporotic fracture.

LEVEL OF EVIDENCE

Prognostic study, level III.

Trend of using cementless total knee arthroplasty: a nationwide analysis from 2015 to 2021

BACKGROUND

Modern cementless total knee arthroplasty (TKA) fixation has shown comparable long-term outcomes to cemented TKA, but the trend of using cementless TKA remains unclear. This study aimed to investigate the trend of using cementless TKA based on a national database.

METHODS

The patients undergoing cementless TKA between 2015 and 2021 were retrospectively extracted from the PearlDiver (Mariner dataset) Database. The annual percentage of cementless TKA was calculated using the following formula: annual number of cementless TKA/annual number of TKA. The trend of the number of patients undergoing cementless TKA was created according to a compounded annual growth rate (CAGR) calculation of annual percentages. Patient age, comorbidity, region, insurance type, etc., were also investigated. Differences were considered statistically significant at P < 0.05.

RESULTS

Of the 574,848 patients who received TKA, 546,731 (95%) underwent cemented fixation and 28,117 (5%) underwent cementless fixation. From 2015 to 2021, the use of cementless TKA significantly increased by 242% from 3 to 9% (compounded annual growth rate (CAGR): + 20%; P < 0.05). From 2015 to 2021, we observed a CAGR greater than 15% for all age groups (< 50, 50-59, 60-69, 70-74, 75 +), insurance types (cash, commercial, government, Medicare, Medicaid), regions (Midwest, Northeast, South, West), sex (male and female), and certain comorbidities (osteoporosis, diabetes mellitus, tobacco use, underweight (BMI < 18.5), rheumatoid arthritis) (P < 0.05 for all). Patients undergoing TKA with chronic kidney disease, prior fragility fractures, and dementia demonstrated a CAGR of + 9%-13% from 2015 to 2021 (P < 0.05).

CONCLUSION

From 2015 to 2021, the use of cementless TKA saw a dramatic increase in all patient populations. However, there is still no consensus on when to cement and in whom. Clinical practice guidelines are needed to ensure safe and effective use of cementless fixation.

High rates of vitamin D insufficiency among patients presenting for total knee arthroplasty

Widely varying prevalence of vitamin D deficiency has been reported in patients presenting for total knee arthroplasty (TKA). The primary aim of this study was to determine vitamin D levels in TKA patients and to compare to patients already routinely evaluated for vitamin D levels, patients with fragility fractures of the distal radius (DRF). There is significant overlap between patients presenting for TKA and with DRF, both in terms of medical comorbidities and overall health status, making these populations suitable comparative cohorts. Wefound that all patients presenting for TKA consultation had vitamin D insufficiency and 33% had vitamin D deficiency, compared to only 37% and 14% in the DRF cohort, a patient population routinely evaluated for vitamin D due to the high risk of deficiency. Furthermore, patients with DRF had higher levels of vitamin D before (38 ± 16 vs. 23 ± 5) and after vitamin D supplementation (39 ± 17 vs. 33 ± 10), suggesting that patients presenting for TKA are at even higher risk of vitamin D insufficiency than patients presenting with DRF. Reassuringly, supplementation successfully corrected 39.0% and 55.8% of patients in the DRF and TKA cohorts, respectively.

Machine Learning for Opportunistic Screening for Osteoporosis and Osteopenia Using Knee CT Scans

PURPOSE

To predict whether a patient has osteoporosis/osteopenia using the attenuation of trabecular bone obtained from knee computed tomography (CT) scans.

METHODS

Retrospective analysis of 273 patients who underwent contemporaneous knee CT scans and dual-energy X-ray absorptiometry (DXA) within 1 year. Volumetric segmentation of the trabecular bone of the distal femur, proximal tibia, patella, and proximal fibula was performed to obtain the bone CT attenuation. The data was randomly split into training/validation (78%) and test (22%) datasets and the performance in the test dataset were evaluated. The predictive properties of the CT attenuation of each bone to predict osteoporosis/osteopenia were assessed. Multivariable support vector machines (SVM) and random forest classifiers (RF) were used to predict osteoporosis/osteopenia.

RESULTS

Patients with a mean age (range) of 67.9 (50-87) years, 85% female were evaluated. Seventy-seven (28.2%) of patients had normal bone mineral density (BMD), 140 (51.3%) had osteopenia, and 56 (20.5%) had osteoporosis. The proximal tibia had the best predictive ability of all bones and a CT attenuation threshold of 96.0 Hounsfield Units (HU) had a sensitivity of .791, specificity of .706, and area under the curve (AUC) of .748. The AUC for the SVM with cubic kernel classifier (AUC = .912) was better than the RF classifier (AUC = .683, P < .001) and better than using the CT attenuation threshold of 96.0 HU at the proximal tibia (AUC = .748, P = .025).

CONCLUSIONS

Opportunistic screening for osteoporosis/osteopenia can be performed using knee CT scans. Multivariable machine learning models are more predictive than the CT attenuation of a single bone.

Titanium Alloy Knee Implant Is Associated with Higher Bone Density over Cobalt Chromium: A Prospective Matched-Pair Case-Control Study

Background

Little is known about the relationship between implant material and periprosthetic bone mineral density (pBMD) in total knee arthroplasty (TKA). The purpose of this study was to investigate the change in pBMD after TKA and to compare pBMD changes between two different implant materials.

Methods

A prospective matched-pair case-control study was conducted on 29 patients who underwent bilateral TKAs. The participants were randomly allocated to undergo cemented TKAs with a titanium nitride (TiN)-coated implant on one knee (TiN group) and a cobalt-chromium (CoCr) implant on the other knee (CoCr group). The pBMD was measured using dual-energy X-ray absorptiometry scans before surgery and at 1 and 2 years after surgery. The results were then compared between the two groups. The pBMDs at longer follow-ups (> 2 years) were estimated using simple radiographs (pBMDe).

Results

At 2 years after surgery, the pBMD significantly decreased in both groups at medial metaphysis of the tibia and anterior portion of the distal femur (all p < 0.001). The CoCr group showed a larger decrease in pBMD than did the TiN group in the medial and anterior metaphysis of the proximal tibia (p = 0.003 and p = 0.046, respectively). The pBMDe was significantly higher in the TiN group at the anterior portion of the distal femur 7 years after surgery (p = 0.019).

Conclusions

The pBMD significantly decreased 2 years after TKA in certain regions regardless of the implant material used. However, the decrease was significantly less in the TiN group in specific regions of the tibia and femur. The TiN implant was beneficial in preserving the periprosthetic bone stock after TKA.

Evaluation of FRAX in patients with periprosthetic fractures following primary total hip and knee arthroplasty

The fracture risk assessment tool (FRAX) is a tool which calculates an individual 10-year fracture risk based on epidemiological data in patients with a risk of osteporosis. The aim of this study was to evaluate the value of FRAX to estimate the risk of postoperative periprosthetic fractures (PPF) in patients following with total hip and knee arthroplasty. 167 patients (137 periprosthetic fractures in total hip arthroplasty and 30 periprosthetic fractures in total knee arthroplasty) were included in this study. Patients' data was retrieved retrospectively. In each patient the 10-year probability of a major osteoporotic fracture (MOF) and an osteoporotic hip fracture (HF) was calculated using FRAX. According to the NOGG guideline 57% of total hip arthroplasty (THA) patients and 43.3% of total knee arthroplasty (TKA) patients were in need of osteoporosis treatment, whereas only 8% and 7% received an adequate one respectively. 56% of the patients with PPF after THA and 57% of the patients with PPF after TKA reported about a previous fracture. Significant associations between the 10-year probability of a MOF and HF calculated by FRAX and PPF in THA and TKA were seen. The results of the present study show that FRAX might have the potential to estimate the PPF in patients following THA and TKA. FRAX should be calculated before and after THA or TKA in order to assess the risk and counsel patients. The data show a clear undertreatment of patients with PPF in respect to osteoporosis.

Stress Fracture of the Femoral Neck Following Total Knee Arthroplasty: A Case Series

A stress fracture of the femoral neck after total knee arthroplasty (TKA) is rare, with few reported cases in the English literature. We defined a stress fracture following TKA as a nontraumatic fracture developing in the femoral neck within six months of TKA. This retrospective case series highlights the predisposing factors, diagnostic challenges, and management of stress femoral neck fractures following TKA. In our series, the major risk factors for the fracture are an increase in the level of activity in osteoporotic bone after a period of relative immobility after TKA, steroid intake, and rheumatoid arthritis. Preoperative dual-energy X-ray absorptiometry (DEXA) screening may help in the early initiation of osteoporosis treatment as the majority of our cases come late in the knee arthritis stage and long after a period of relative inactivity. Timely diagnosis and management of a stress femur neck fracture in the early period may prevent fracture displacement, avascular necrosis, and nonunion.

Prevalence of osteoporosis and osteopenia in elderly patients scheduled for total knee arthroplasty

INTRODUCTION

Osteoporosis is a common comorbidity in elderly patients with osteoarthritis (OA) and may increase perioperative complications in orthopedic surgery (e.g., component migration, periprosthetic fractures). As there is no investigation of bone mineral density (BMD) in elderly patients prior to total knee arthroplasty (TKA) in Europe, we investigated this issue with a particular focus on a potential treatment gap.

MATERIALS AND METHODS

We assessed the BMD by dual-energy X-ray absorptiometry (DXA) in 109 consecutive elderly patients (age ≥ 70 years) scheduled for TKA. In addition to a detailed assessment of osteoporosis and osteopenia, the influence of clinical risk factors and radiological OA severity on BMD was evaluated using group comparisons and linear regression models. In addition, we analyzed differences in BMD between patients scheduled for TKA vs. total hip arthroplasty (THA).

RESULTS

Of the included 109 patients, 19 patients (17.4%) were diagnosed with osteoporosis and 50 (45.9%) with osteopenia. In the osteoporotic patients, a clinically relevant underdiagnosis concomitant with a serious treatment gap was observed in 95.0% of the patients. Body mass index, OA grade, and glucocorticoid use were identified as independent factors associated with BMD. No differences in BMD were found between the patients scheduled for TKA vs. THA.

CONCLUSIONS

Considering the high prevalence of osteoporosis and osteopenia in elderly patients, DXA screening should be recommended for patients ≥ 70 years indicated for TKA.

Reduced Awareness for Osteoporosis in Hip Fracture Patients Compared to Elderly Patients Undergoing Elective Hip Replacement

Background: Osteoporotic fractures are associated with a loss of quality of life, but only few patients receive an appropriate therapy. Therefore, the present study aims to investigate the awareness of musculoskeletal patients to participate in osteoporosis assessment and to evaluate whether there are significant differences between acute care patients treated for major fractures of the hip compared to elective patients treated for hip joint replacement.; Methods: From May 2015 to December 2016 patients who were undergoing surgical treatment for proximal femur fracture or total hip replacement due to osteoarthritis and were at risk for an underlying osteoporosis (female > 60 and male > 70 years) were included in the study and asked to complete a questionnaire assessing the awareness for an underlying osteoporosis. ASA Score, FRAX Score, and demographic information have also been examined. Results: In total 268 patients (female = 194 (72.0%)/male = 74 (28%)), mean age 77.7 years (±7.7) undergoing hip surgery were included. Of these, 118 were treated for fracture-related etiology and 150 underwent total hip arthroplasty in an elective care setting. Patients were interviewed about their need for osteoporosis examination during hospitalization. Overall, 76 of 150 patients receiving elective care (50.7%) considered that an examination was necessary, whereas in proximal femur fracture patients the awareness was lower, and the disease osteoporosis was assessed as threatening by significantly fewer newly fractured patients. By comparison, patients undergoing trauma surgery had a considerably greater risk of developing another osteoporotic fracture than patients undergoing elective surgery determined by the FRAX® Score (p ≤ 0.001).; Conclusions: The patients’ motivation to endure additional osteoporosis diagnostic testing is notoriously low and needs to be increased. Patients who underwent acute care surgery for a fragility proximal femur fracture, although acutely affected by the potential consequences of underlying osteoporosis, showed lower awareness than the elective comparison population that was also on average 6.1 years younger. Although elective patients were younger and at a lower risk, they seemed to be much more willing to undergo further osteoporosis assessment. In order to better identify and care for patients at risk, interventions such as effective screening, early initiation of osteoporosis therapy in the inpatient setting and a fracture liaison service are important measures.

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

BACKGROUND

Metabolic bone diseases in the total joint arthroplasty (TJA) population are undertested and undertreated, leading to increased risk of adverse outcomes such as periprosthetic fractures. This study aims to better characterize the current state of bone care in TJA patients using Fracture Risk Assessment Tool (FRAX) score risk stratifications.

METHODS

In total, 505 consecutive TJA patients who meet the Endocrine Society guidelines for osteoporosis screening were included for review. They were divided into a high risk or low risk group depending on FRAX scores and were compared based on screening, diagnosis, and treatment of metabolic bone disease. Logistic regression models were used to analyze factors influencing screening and treatment. A population analysis involving 2,000 TJA patients, and a complication analysis involving 40 periprosthetic fracture patients were conducted.

RESULTS

Among high risk patients undergoing TJA, 90% did not receive any pharmacological treatment for osteoporosis, 45% were not treated with vitamin D or calcium, and 88% did not receive bone density testing in the routine care period. Among patients with pre-existing osteoporosis undergoing TJA, 80% were not treated with any osteoporosis medications and 33% of these patients were not taking vitamin D or calcium. Female gender and past fracture history contributed to whether patients received screening and treatment. Patients with periprosthetic hip fractures have significantly higher FRAX scores compared to control THA patients.

CONCLUSION

There are significant gaps in metabolic bone care of the geriatric TJA population regarding both screening and treatment. Metabolic bone care and risk identification with FRAX should be highly considered for TJA patients.

Impact of keel saw blade design and thickness on the incidence of tibial plateau fracture and tibial implant-loosening in cementless medial UKR

BACKGROUND

Tibial plateau fractures and tibial implant- loosening are severe complications in cementless unicompartmental knee replacement (UKR). The tibial keel preparation is particularly demanding and different saw blades can be used. It was hypothesized that different blade designs and thickness have an influence on the frequency of tibial plateau fractures and implant-loosening in cementless medial UKR.

METHODS

1258 patients with cementless medial UKR were included in this retrospective study between 2013 and 2020. The tibial keel cut was performed either with a double keel saw blade (DKS; 2.8 mm) and added hand guided pick or a mono reciprocating saw blade (RKB) of different thickness (2.5 mm; 2.65 mm; 2.75 mm). Tibial plateau fracture and loosening were demonstrated by standard two-plane radiographs. Tibial implant-loosening was defined as complete radiolucency and implant migration. Fracture and loosening were combined with pain and loss of function.

RESULTS

In 126 patients (10%) the tibial keel was prepared with DKS, in 407 patients (32.4%) with RKB 2.5 mm, in 330 patients (26.2%) with RKB 2.65 mm and in 395 patients (31.4%) with 2.75 mm. In 4 patients (3.17%) with DKS tibial plateau fracture occurred, in 4 patients (0.99%) with 2.5 mm RKB, in 3 patients (0.92%) with 2.65 mm RKB and in 1 patient (0.25%) with 2.75 mm RKB. Significantly fewer fractures occurred with a RKB design (p = 0.007). A negative correlation between fracture incidence and RKB saw blade thickness was found (Spearman-r = - 0.93). No difference for tibial implant-loosening was shown (p = 0.51).

CONCLUSION

Different blade designs and thickness have a significant influence on the incidence of tibial plateau fractures and aseptic tibial implant-loosening. The incidence of tibial plateau fractures in cementless medial UKR can be reduced by changing the design and thickness of the tibial keel saw blade. Greater thickness of RKB leads to significantly fewer tibial plateau fractures while the incidence of implant-loosening is not increasing.

TRIAL REGISTRATION

This study was retrospectively registered and ethical approval was waived by the local ethical committee (No. 2020-1174).

The effect of whole-body vibration in osteopenic patients after total knee arthroplasty: a randomized controlled trial

BACKGROUND

Total knee arthroplasty (TKA) is an important treatment for knee osteoarthritis, but the result of whole-body vibration (WBV) in knee function rehabilitation and bone loss with osteopenia was unknown. Therefore, the purpose of this study is to study whether low-frequency, low-amplitude WBV can improve the clinical outcome of knee osteoarthritis.

METHODS

This study was randomized and included 67 osteopenic patients (55-90 years, 85% women) for TKA surgery (control group N = 32, WBV group N = 35). All selected patients after TKA surgery tested clinical results, such as knee function and bone mass in baseline, 3 months after surgery, and 6 months after surgery.

RESULTS

Compared to the control group, the WBV group improved pain scores, thigh circumference, lower limb muscle strength, joint activity, and joint function in 6 months after surgery. WBV intervention also improves bone density in the spine, the microstructure of the radius and tibia, and the bone turnover marker. At 3 months after TKA surgery, the WBV group had no significant effect on knee function and bone loss.

CONCLUSIONS

Whole-body vibration for osteopenic patients with knee arthroplasty showed good therapeutic results in 6 months after TKA surgery, but the long-term therapeutic effect still needs to be further observed.

Artificial Neural Networks Can Predict Early Failure of Cementless Total Hip Arthroplasty in Patients With Osteoporosis

BACKGROUND

Total hip arthroplasty (THA) done in the aging population is associated with osteoporosis-related complications. The altered bone density in osteoporotic patients is a risk factor for revision surgery. This study aimed to develop and validate machine learning (ML) models to predict revision surgery in patients with osteoporosis after primary noncemented THA.

METHODS

We retrospectively reviewed a consecutive series of 350 patients with osteoporosis (T-score less than or equal to -2.5) who underwent primary noncemented THA at a tertiary referral center. All patients had a minimum 2-year follow-up (range: 2.1 to 5.6). Four ML algorithms were developed to predict the probability of revision surgery, and these were assessed by discrimination, calibration, and decision curve analysis.

RESULTS

The overall incidence of revision surgery was 5.2% at a mean follow-up of 3.7 years after primary noncemented THA in osteoporotic patients. Revision THA was done because of periprosthetic fracture in nine patients (50%), aseptic loosening/subsidence in five patients (28%), periprosthetic joint infection in two patients (11%) and dislocation in two patients (11%). The strongest predictors for revision surgery in patients after primary noncemented THA were female sex, BMI (>35 kg/m2), age (>70 years), American Society of Anesthesiology score (≥3), and T-score. All four ML models demonstrated good model performance across discrimination (AUC range: 0.78 to 0.81), calibration, and decision curve analysis.

CONCLUSION

The ML models presented in this study demonstrated high accuracy for the prediction of revision surgery in osteoporotic patients after primary noncemented THA. The presented ML models have the potential to be used by orthopaedic surgeons for preoperative patient counseling and optimization to improve the outcomes of primary noncemented THA in osteoporotic patients.

Total knee arthroplasty in hemophilia: lessons learned and projections of what's next for hemophilic knee joint health

INTRODUCTION

The purpose of this article has been to review the literature on total knee arthroplasty (TKA) in people with hemophilia (PWH), to mention the lessons we have learned from our own experience and to try to find out what the future of this type of surgery will be.

AREAS COVERED

A Cochrane Library and PubMed (MEDLINE) search of studies related to TKA PWH was analyzed. In PWH, the complication rate after TKA can be up to 31.5%. These include infection (7.1%) and bleeding in the form of hematoma, hemarthrosis or popliteal artery injury (8.9%). In a meta-analysis the revision arthroplasty rate was 6.3%. One-stage or two-stage revision arthroplasty due to infection (septic loosening) is not always successful despite providing correct treatment (both hematological and surgical). In fact, the risk of prosthetic re-infection is about 10%. It is necessary to perform a re-revision arthroplasty, which is a high-risk and technically difficult surgery that can sometimes end in knee arthrodesis or above-the-knee amputation of the limb.

EXPERT OPINION

TKA (both primary and revision) should be performed in centers specialized in orthopedic surgery and rehabilitation (knee) and hematology (hemophilia), and with optimal coordination between the medical team.

Team Approach: Preoperative Management of Metabolic Conditions in Total Joint Replacement

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Total joint arthroplasties (TJAs) of the knee and hip have been considered 2 of the most successful surgical procedures performed to date.

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Frailty is defined as increased vulnerability to adverse outcomes with physiologic stress.

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Preoperative optimization of frailty and metabolic bone conditions, including osteoporosis, vitamin D deficiency, and diabetes, through a multidisciplinary approach can help improve outcomes and minimize costs after TJA.

A Review of Periprosthetic Tibial Fractures: Diagnosis and Treatment

Periprosthetic fracture occurring during or after total knee arthroplasty is a rare injury. Literature concerning periprosthetic tibial factures is sparse, and there is limited guidance for evidence-based management. This review aims to provide readers with an overview of the epidemiology, risk factors, and classification of these fractures. Management includes nonoperative treatment of nondisplaced fractures, fixation for those with stable implants, and revision for those with loose implants.

The Human Gut Microbiota: A Key Mediator of Osteoporosis and Osteogenesis

An expanding body of research asserts that the gut microbiota has a role in bone metabolism and the pathogenesis of osteoporosis. This review considers the human gut microbiota composition and its role in osteoclastogenesis and the bone healing process, specifically in the case of osteoporosis. Although the natural physiologic processes of bone healing and the pathogenesis of osteoporosis and bone disease are now relatively well known, recent literature suggests that a healthy microbiome is tied to bone homeostasis. Nevertheless, the mechanism underlying this connection is still somewhat enigmatic. Based on the literature, a relationship between the microbiome, osteoblasts, osteoclasts, and receptor activator of nuclear factor-kappa-Β ligand (RANKL) is contemplated and explored in this review. Studies have proposed various mechanisms of gut microbiome interaction with osteoclastogenesis and bone health, including micro-RNA, insulin-like growth factor 1, and immune system mediation. However, alterations to the gut microbiome secondary to pharmaceutical and surgical interventions cannot be discounted and are discussed in the context of clinical therapeutic consideration. The literature on probiotics and their mechanisms of action is examined in the context of bone healing. The known and hypothesized interactions of common osteoporosis drugs and the human gut microbiome are examined. Since dysbiosis in the gut microbiota can function as a biomarker of bone metabolic activity, it may also be a pharmacological and nutraceutical (i.e., pre- and probiotics) therapeutic target to promote bone homeostasis.

The association between bone mineral density and postoperative drainage volume following cruciate-substituting primary total knee arthroplasty: a cross-sectional study

Background

The prevalence of osteoporosis in patients who undergo a primary total knee arthroplasty (TKA) is increasing. Low bone mineral density (BMD) is related to unfavorable outcomes following TKA such as migration of uncemented tibial components. Postoperative blood loss in TKA is an important complication. Non-modifying predicting factors for postoperative blood loss in patients undergoing primary TKA need further elucidation. Studies on the association between BMD and blood loss after TKA are limited. We aimed to demonstrate the relationship between BMD and postoperative drainage volume following primary TKA.

Methods

A cross-sectional study was conducted between January 2014 and August 2020. A total of 119 primary varus osteoarthritis knees with BMD results were included in the study. Patients with secondary causes of osteoporosis were excluded.

Results

The median postoperative drainage volume of participants in the normal total hip BMD group and the normal trochanter BMD group was higher than that of patients in the low total hip BMD group and the low trochanter BMD group (285.0 ml vs 230.0 ml, P = 0.003; 282.5 ml vs 240.0 ml, P = 0.013, respectively). Multivariate regression analyses showed that operative time, spinal anesthesia, and normal total hip BMD status were significant predictive factors associated with increased postoperative drainage volume (P = 0.014, 0.022, and 0.013, respectively). No association was identified between the lumbar spine BMD status and postoperative drainage volume.

Conclusions

The relationship between BMD and postoperative blood loss in primary TKA was identified in this study. Normal total hip BMD was found to be associated with an increased postoperative drainage volume after primary TKA compared with low BMD.

Anterior femoral notching ≥ 3 mm is associated with increased risk for supracondylar periprosthetic femoral fracture after total knee arthroplasty: a systematic review and meta-analysis

PURPOSE

Anterior femoral notching (AFN) may be associated with a higher risk for supracondylar periprosthetic fracture (sPPF) after total knee arthroplasty (TKA), although studies have yielded inconclusive results. We aimed to systematically investigate and meta-analyze the best available evidence regarding the association between AFN and the risk of sPPF after TKA.

METHODS

A comprehensive search of PubMed, Scopus, Mendeley, Google Scholar and Cochrane databases was performed, from conception to February 29, 2020. Data were expressed as odds ratio (OR) with 95% confidence intervals (CI). I²-index was employed for heterogeneity. Newcastle-Ottawa scale was implemented for quality assessment of the included studies.

RESULTS

Nine studies fulfilled the eligibility criteria, including a total of 3264 patients subjected to TKA. Among them, there were 150 patients who sustained a sPPF. Overall, patients exposed to AFN (AFN group) demonstrated an increased risk for sPPF compared to those not exposed (control group) (OR 3.91, 95% CI 1.22-12.58, p = 0.02; I² 68.52%). Subgroup analysis based on AFN depth with a cut-off value of 3 mm further clarified this association. Patients with AFN ≥ 3mm were at higher risk for sPPF compared to patients with AFN < 3 mm and control group (OR 4.85, 95% CI 2.08-11.33, p = 0.00; I² 0.0%). On the contrary, fracture risk was not significant for patients with AFN < 3 mm compared to the control group (OR 5.0, 95% CI 0.44-56.82, p = 0.19; I² 42.99%).

CONCLUSION

Patients, exposed to AFN ≥ 3 mm in depth, are at higher risk for sustaining a sPPF.

Prevalence and Risk Factors of Osteoporosis in Chinese Postmenopausal Women Awaiting Total Knee Arthroplasty

Background

Total knee arthroplasty (TKA) complications associated with low bone quality are challenging for orthopaedic surgeons to treat, but little is known about bone quality in Chinese postmenopausal women awaiting TKA. This study investigated the incidence of osteoporosis (OP) and explored the preoperative risk factors for OP in this population.

Methods

We retrospectively reviewed the data of Chinese postmenopausal women who were indicated for TKA between May 2017 and June 2020. The bone mineral density (BMD) of the hip and lumbar spine and multiple preoperative parameters were collected and analyzed. Binary logistic regression analysis was performed to identify independent risk factors for OP in this population.

Results

A total of 204 postmenopausal women with advanced knee OA were included in the study (age: 69.7±8.5 years; body mass index [BMI]: 25.5±4.0 kg/m2). The OP prevalence among all participants was 59.8%, and the patients aged 60–80 years had a significantly lower BMD than did the age/ethnicity-adjusted population. An age ≥60 years, a BMI<25, and the presence of a varus knee deformity were independent risk factors for preoperative OP in the postmenopausal women awaiting TKA.

Conclusion

The prevalence of OP in Chinese postmenopausal women awaiting TKA is higher than that in the age/ethnicity-adjusted normal population. An age ≥60 years, a BMI<25, and the presence of a varus knee deformity are independent risk factors that can be used to predict preoperative OP in this population.

[Progress of change in bone mineral density after knee arthroplasty]

Objective

To summarize research progress of change in bone mineral density (BMD) after knee arthroplasty and its diagnostic methods, influencing factors, and drug prevention and treatment.

Methods

The relevant literature at home and abroad was reviewed and summarized from research status of the advantages and disadvantages of BMD assessment methods, the trend of changes in BMD after knee arthroplasty and its influencing factors, and the differences in effectiveness of drugs.

Results

The central BMD and mean BMD around the prosthesis decrease after knee arthroplasty, which is closely associated with body position, age, weight, daily activities, and the fixation methods, design, and material of prosthesis. Denosumab, bisphosphonates, and teriparatide et al. can decrease BMD loss after knee arthroplasty.

Conclusion

BMD after knee arthroplasty decreases, which is related to various factors, but the mechanism is unclear. At present, some inhibitors of bone resorption can decrease BMD loss after knee arthroplasty. However, its long-term efficacy remains to be further explored.

Underestimation and undertreatment of osteoporosis in patients awaiting primary total knee arthroplasty

INTRODUCTION

Osteoporosis is generally regarded as a risk factor for periprosthetic fracture during or after primary total knee arthroplasty (TKA). Despite this, little is known about osteoporosis in patients undergoing elective primary TKA Therefore, we sought to investigate the prevalence of osteoporosis and rates of pharmacologic osteoporosis treatment prior to primary TKA. We hypothesized that preoperative osteoporosis is underestimated and undertreated in the primary TKA population.

MATERIALS AND METHODS

This retrospective study included consecutive 1972 patients scheduled for elective primary TKA at a single tertiary hospital (age, 50-89 years). Charts were reviewed for patient demographics, prior pharmacologic osteoporosis treatment and Knee Society (KS) scoring system and WOMAC score. Dual energy X-ray absorptiometry (DEXA) measurement of the lumbar vertebrae and proximal femur was performed in all patients on the day before surgery. The associations of BMD with age, sex, body mass index (BMI), and clinical outcome were analyzed.

RESULTS

The prevalence of osteoporosis was 50.0% (53.4% in women and 7.0% in men). Among patients with osteoporosis, only 15.1% (149/986) of patients (15.0% in women and 30.0% in men) had pharmacological osteoporosis treatment prior to primary TKA. Age, sex and WOMAC stiffness showed association with osteoporosis. Sex (odds ratio (OR): 20.83, p < 0.001) was the most significant factor associated with osteoporosis.

CONCLUSION

Osteoporosis was highly prevalent in patients awaiting TKA, but the rates of diagnosis and pharmacologic osteoporosis treatment were low. Therefore, more attention needs to estimate and treat osteoporosis in patients awaiting primary TKA, especially in female patients.