Bone mineral density changes after total knee replacement in women over the age of 65

Preoperative bone assessment by bone mineral density and bone turnover in patients undergoing total knee arthroplasty

Background

The preoperative overall bone quality in patients undergoing total knee arthroplasty (TKA) might influence the development of postoperative bone-derived complications. This study was performed to simultaneously evaluate the baseline bone mineral density (BMD) and bone turnover in these patients.

Methods

We prospectively measured the lumbar spine, total hip, and femoral neck BMD using dual-energy X-ray absorptiometry (DXA) in 214 patients (239 knees; women, 199 knees; men, 40 knees) 1 day preoperatively. Women were stratified into three age groups: <70 years (60s), <80 years (70s), and ≥80 years (80s). We assessed bone turnover using the urinary level of N-telopeptide (NTx) normalized to creatinine (NTx/Cre).

Results

The prevalence of osteoporosis as assessed by DXA (T-score of ≤ -2.5) was 22% in women and 5% in men. A decline in BMD with aging was found in the hip but not in the lumbar spine with significant differences among ages. Women showed a higher NTx/Cre level than men (p = 0.033). An NTx/Cre level suggesting a high fracture risk (>56.5 mmol BCE/mmol Cre) was present in 54% of women and 35% of men (p = 0.037). No significant differences were found in this prevalence among age groups in women. Seventeen percent of women and 0% of men had both osteoporosis and a high fracture risk simultaneously (p = 0.002). The proportion of women in this category was lower in the 60s than 70s age group (p = 0.019).

Conclusions

Preoperative bone health screening before TKA might be necessary for women aged ≥70 years to prevent complications caused by perioperative poor bone condition.

[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.

A Review on Bone Mineral Density Loss in Total Knee Replacements Leading to Increased Fracture Risk

The link between low bone mineral density (BMD) scores leading to greater fracture risk is well established in the literature; what is not fully understood is the impact of total knee replacements/revisions or arthroplasties on BMD levels. This literature review attempts to answer this question. Several different databases using specific key terms were searched, with additional papers retrieved via bibliographic review. Based on the available evidence, total knee replacements/revisions and arthroplasties lower BMD and thus increase fracture risk. This review also addresses the possible implications of this research and possible options to reduce this risk.

Preoperative Bone Mineral Density and Bone Turnover in Women Before Primary Knee Arthroplasty

PURPOSE

The preoperative prevalence of osteoporosis and/or osteopenia and overall bone quality in prospective total knee arthroplasty (TKA) patients may affect the postoperative outcome after prosthetic insertion into the bone. The purpose of this study is to determine the baseline bone mineral density (BMD) and bone turnover in preoperative, female, primary TKA patients.

METHODS

We prospectively measured the lumbar spine and hip BMDs using dual-energy X-ray absorptiometry (DEXA) scans in a cohort of 119 knees (107 patients) one day before surgery. We also assessed bone turnover using urinary levels of N-telopeptide (NTX), a type I collagen crosslinker, normalized to creatinine.

RESULTS

The prevalence of osteoporosis by DEXA scan (T-score ≤ -2.5) among the TKAs was 12% in the spine and 10% in the hip. Eighty-three knees (70%) had osteopenia or osteoporosis of either the spine or hip. The mean T-score of the spine was -0.7 (SD 1.6), which is within normal limits, and of the hip was -1.2 (SD 1.0), which is defined as osteopenia. The mean Z-scores of 0.9 (SD 1.4) in the spine and 0.6 (SD 0.9) in the hip were positive. The median urinary NTX/creatinine ratio was elevated at 58.1 (interquartile range: 13.7 to 188.4).

CONCLUSION

Based on Z-scores, the TKA patients had higher spine and hip BMDs than the age-matched general population. Elevated NTX levels may suggest a systemic or local abnormal bone turnover. Further study is needed to determine whether such turnover, as a type of patient-related medical systemic disorder, affects postoperative clinical outcomes.

A study investigating short- and medium-term effects on function, bone mineral density and lean tissue mass post-total knee replacement in a Caucasian female post-menopausal population: implications for hip fracture risk

Significant increased hip fracture incidence has been reported in the year following total knee replacement. This study demonstrates that bone and muscle loss is a post-surgical consequence of total knee replacement, alongside poor outcomes in function and activity potentially contributing to reduced quality of life and increased hip fracture risk.

INTRODUCTION

A significant increase in hip fracture incidence in the year following total knee replacement (TKR) surgery has been reported. This study investigated function and activity following TKR and the effects of limited mobility on bone and muscle loss and their potential contribution to hip fracture risk.

METHODS

Changes in dual-energy X-ray absorptiometry (DXA) (GE Lunar Prodigy, Bedford MA), bone mineral density (BMD) at the neck of femur (NOF), total hip region (TH) and lumbar spine were measured alongside leg lean tissue mass (LLTM) in post-menopausal Caucasian females following TKR (N = 19) compared to controls (N = 43). Lumbar spine trabecular bone scores (TBSs) were calculated. Ipsilateral/contralateral weight bearing, lower limb function, 3-day pedometer readings, pain levels and falls were also recorded. Measurements were obtained at pre-surgery baseline and at 6 weeks, 6 months and 12 months post-surgery.

RESULTS

No statistically significant differences were demonstrated between groups at baseline bilaterally in LLTM or BMD at the NOF and TH. Losses in ipsilateral NOF and TH BMD and contralateral LLTM were significantly higher in the TKR group at 6 months. Impairment in function and weight bearing persisted in the TKR group 12 months post-operatively alongside deficits in bilateral muscle mass and ipsilateral NOF and TH BMD. Falls incidence was not significantly higher in the TKR group.

CONCLUSIONS

Bone loss at the hip with associated muscle loss is a consequence of TKR that, in addition to poor patient outcomes in function and activity, potentially contributes to increased hip fracture risk in the year following surgery.

Bone quality of the calcaneus 5years after total knee arthroplasty

We used non-invasive broadband ultrasound attenuation (BUA) to determine whether the pre-surgical bone quality of the calcaneus was improved 5years postoperatively, and whether the interval between total knee arthroplasty (TKA) surgeries influenced post-surgical calcaneal bone quality. All patients underwent scheduled, staged, bilateral TKA. Twenty-one patients (42 TKAs) with bilateral knee osteoarthritis were evaluated. One day before and 5years after TKA, BUA through the os calcis on the surgical side was measured. Fourteen out of 21 patients showed post-surgical improvement in BUA bilaterally. When all 42 cases were considered together there was a significant improvement in BUA 5years after surgery (P=0.042). There were no significant correlations between the changes in BUA on each side and the interval between TKA surgeries.

Prevalence of osteoporosis in female patients with advanced knee osteoarthritis undergoing total knee arthroplasty

This study sought to demonstrate bone mineral density (BMD) conditions in elderly female patients with knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA). In addition, we sought to determine whether their BMD conditions differ from those of community-based females without knee OA. Finally we sought to determine whether clinical statuses are related to BMD in the knee OA patients. BMD conditions in 347 female patients undergoing TKA and 273 community-based females were evaluated. Additionally, comparative analyses of BMD between age and body mass index-matched knee OA groups (n=212) and the control groups (n=212) were performed. In the pre-matched knee OA group, regression analyses were performed to determine whether preoperative clinical statuses were related to BMD. Considerable prevalence of coexistent osteoporosis (31%) was found in the pre-matched knee OA patients undergoing TKA. We found no significant differences of the BMD T-scores and the prevalence of osteoporosis between the age and body mass index-matched knee OA and control groups. In the pre-matched knee OA patients, poorer preoperative clinical scores were related to poorer BMD T-scores in the proximal femur and/or lumbar spine. Our study suggests that more attention should be paid to identify and treat osteoporosis in elderly female patients with advanced knee OA undergoing TKA.