VASO (Vitamin D and Arthroplasty Surgery Outcomes) study - supplementation of vitamin D deficiency to improve outcomes after total hip or knee replacement: study protocol for a randomised controlled feasibility trial

Evaluation of Preoperative Variables that Improve the Predictive Accuracy of the Risk Assessment and Prediction Tool in Primary Total Hip Arthroplasty

INTRODUCTION

Discharge disposition after total joint arthroplasty may be predictable. Previous literature has attempted to improve upon models such as the Risk Assessment and Prediction Tool (RAPT) in an effort to optimize postoperative planning. The purpose of this study was to determine whether preoperative laboratory values and other previously unstudied demographic factors could improve the predictive accuracy of the RAPT.

METHODS

All patients included had RAPT scores in addition to the following preoperative laboratory values: red blood cell count, albumin, and vitamin D. All values were recorded within 90 days of surgery. Demographic variables including marital status, American Society of Anesthesiologists (ASA) scores, body mass index, Charlson Comorbidity Index, and depression were also evaluated. Binary logistic regression was used to determine the significance of each factor in association with discharge disposition.

RESULTS

Univariate logistic regression found significant associations between discharge disposition and all original RAPT factors as well as nonmarried patients (P < 0.001), ASA class 3 to 4 (P < 0.001), body mass index >30 kg/m2 (P = 0.065), red blood cell count <4 million/mm3 (P < 0.001), albumin <3.5 g/dL (P < 0.001), Charlson Comorbidity Index (P < 0.001), and a history of depression (P < 0.001). All notable univariate models were used to create a multivariate model with an overall predictive accuracy of 90.1%.

CONCLUSIONS

The addition of preoperative laboratory values and additional demographic data to the RAPT may improve its PA. Orthopaedic surgeons could benefit from incorporating these values as part of their discharge planning in THA. Machine learning may be able to identify other factors to make the model even more predictive.

Risk Factors in Patients Who Had Prior Renal or Liver Transplant Undergoing Primary Total Knee Arthroplasty

BACKGROUND

More solid organ transplant (SOT) patients are undergoing total knee arthroplasty (TKA). This study identifies risk factors for complications, implant survivorship, and mortality in TKA patients who had prior SOT.

METHODS

We identified 176 TKAs in patients who had prior SOT. Of these, 77 had a prior renal (RT), 77 had a prior liver (LT) transplant, and 22 had multiple prior transplants (MT). Median survival was estimated using Kaplan-Meier. Univariate analyses were assessed with mixed-effects logistic regressions for complications and Cox-regressions for mortality. Median follow-up was 63 months (range, 24 to 109).

RESULTS

At least one acute medical complication occurred in 25, 13, and 27% of cases with prior RT, LT, and MT, respectively (P = .12). None of the variables were significantly associated with acute medical complications. At least one surgical complication occurred in 14, 13 and 14% of cases with prior RT, LT, and MT, respectively (P = 1). Vitamin D supplementation (Odds Ratio [OR] = 0.38, P < .03) was associated with lower risk of surgical complications. Reoperation and revision rates were 5 and 3%, respectively. Older age at time of transplantation and greater level of serum creatinine at time of TKA were associated with lower risk (OR = 0.96, P = .01), and higher risk of reoperation (OR = 4.9, P = .01), respectively. Coronary artery disease was associated with higher mortality (Hazard Ratio = 2.35, P = .01).

CONCLUSIONS

Vitamin D was associated with lower surgical complications, whereas a younger age at time of transplantation increased the risk of reoperation. Additionally, SOT patients with coronary artery disease demonstrated higher mortality after TKA.

High-Dose Vitamin D Supplementation Can Correct Hypovitaminosis D Prior to Total Knee Arthroplasty

BACKGROUND

Vitamin D deficiency in the perioperative surgical period is associated with inferior surgical outcomes. There are no established preoperative supplementation regimens in the orthopedic literature. The purpose of this study is to compare the efficacy between 2 different supplementation regimens of vitamin D prior to total knee arthroplasty.

METHODS

We conducted a retrospective analysis of 174 patients identified as vitamin D deficient (25(OH)D < 30 ng/mL) who received one of 2 vitamin D supplementation protocols: (1) daily supplementation with D3 on a sliding scale from 1000 to 6000 IU or (2) a loading dose of 50,000 IU D3 weekly for 4 weeks then 2000 IU/d. Serum vitamin D levels were measured at 3 months and 1 month preoperatively.

RESULTS

Mean patient age was 65.5(±8.6) years, and 54.6% were female. Deficiency was corrected in 73.3% of patients in the loading dose group and 42.4% of patients in the daily, low-dose group [χ² (1, N = 174) = 16.53, P < .001]. Patients in the loading dose group also achieved a greater average correction in vitamin D levels.

CONCLUSION

This is the first study to compare preoperative vitamin D supplementation protocols. A loading dose regimen of 50,000 IU weekly for 4 weeks followed by a maintenance dose of 2000 IU/d more effectively corrects vitamin D deficiency compared to a low-dose, daily regimen among total knee arthroplasty patients. We recommend this regimen for deficiency correction in patients who have been screened to be deficient in vitamin D preoperatively.

The risk of revision following total hip arthroplasty in patients with inflammatory bowel disease, a registry based study

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the intestinal tract and is associated with decreased bone mineral density. IBD patients are at higher risk of osteopenia, osteoporosis and fracture compared to non-IBD patients. The impact of IBD on the performance of orthopedic implants has not been well studied. We hypothesized that a history of IBD at the time of primary total hip arthroplasty (THA) would increase the risk of subsequent failure as assessed by revision surgery. A retrospective implant survival analysis was completed using the Swedish Hip Arthroplasty Registry and the Sweden National Patient Register. A total of 150,073 patients undergoing THA for osteoarthritis within an 18-year period were included in the study. THA patients with (n = 2,604) and without (n = 147,469) a history of IBD at the time of THA were compared with primary revision as the main endpoint and adjusted using sex, age category and comorbidity (Elixhauser scores) as covariates. We found that patients with a history of IBD had a relatively higher risk of revision surgery for septic causes while the non-IBD patients had a relatively higher risk of revision for aseptic causes (p = 0.004). Our findings suggest there may be an association between gut health and THA performance.

Outcome of total hip and total knee arthroplasty and vitamin D homeostasis

BACKGROUND

Low levels of vitamin D are common in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), but it is still unclear whether the outcome of such surgery is related to vitamin D levels.

SOURCES OF DATA

Publicly available electronic databases were systematically reviewed to update knowledge about the role of vitamin D in THA and TKA patients, and to appraise the correlation between vitamin D levels before surgery and post-surgical outcomes. Eight studies were included in our review: six employed prospective observational designs, two reported retrospective database interrogations. Six prospective observational studies and two retrospective database interrogations matched inclusion and exclusion criteria.

AREAS OF AGREEMENT

Patients undergoing THA and TKA have a high prevalence of hypovitaminosis D. Five of eight studies (62.5%) report a statistically significant association between low vitamin D status and worse outcomes after THA and TKA.

AREAS OF CONTROVERSY

Different explanations have been proposed for vitamin D insufficiency, but some authors have questioned the correctness of the methods used to measure the vitamin D levels.

GROWING POINTS

A trial focusing on the role of vitamin D supplementation on safety and outcomes of patients undergoing THA and TKA with low vitamin D status is ongoing.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies should explore the possible causal relationship between vitamin D status and outcomes of THA and TKA and verify the laboratory methods to analyse it.

Preoperative Vitamin D Repletion in Total Knee Arthroplasty: A Cost-Effectiveness Model

BACKGROUND

Recent studies have identified vitamin D deficiency (serum 25-hydroxyvitamin D [25(OH)D] < 20 ng/L) as a potentially modifiable risk factor for prosthetic joint infection (PJI) in arthroplasty. The purpose of this study is to determine whether implementation of preoperative 25(OH)D repletion is cost-effective for reducing PJI following total knee arthroplasty (TKA).

METHODS

A cost estimation predictive model was generated to determine the utility of both selective and nonselective 25(OH)D repletion in primary TKA to prevent PJI. Input data on the incidence of 25(OH)D deficiency, relative complication rates, and costs of serum 25(OH)D repletion and 2-stage revision for PJI were derived from previously published literature identified using systematic review and publicly available data from Medicare reimbursement schedules. Mean, lower, and upper bounds of 1-year cost savings were computed for nonselective and selective repletion relative to no repletion.

RESULTS

Selective preoperative 25(OH)D screening and repletion were projected to result in $1,504,857 (range, $215,084-$4,256,388) in cost savings per 10,000 cases. Nonselective 25(OH)D repletion was projected to result in $1,906,077 (range, $616,304-$4,657,608) in cost savings per 10,000 cases. With univariate adjustment, nonselective repletion is projected to be cost-effective in scenarios where revision for PJI costs ≥$10,636, incidence of deficiency is ≥1.1%, and when repletion has a relative risk reduction ≥4.2%.

CONCLUSION

This predictive model supports the potential role of 25(OH)D repletion as a cost-effective mechanism of reducing PJI risk in TKA. Given the low cost of 25(OH)D repletion relative to serum laboratory testing, nonselective repletion appears to be more cost-effective than selective repletion. Further prospective investigation to assess this modifiable risk factor is warranted.

Association Between Preoperative Vitamin D Status and Short-Term Physical Performance after Total Hip Arthroplasty: A Prospective Study

BACKGROUND

Insufficient serum vitamin D concentrations (50-75 nmol/L) are prevalent in 40-65% of patients who require total hip arthroplasty (THA). This could impair physical recovery after surgery. This study investigated the association between preoperative vitamin D status and physical performance after THA. Additionally, postoperative changes in vitamin D concentrations were measured.

METHODS

We included 87 patients scheduled for elective THA and aged ≥65 years. Three groups were recruited: patients classified as vitamin D deficient (< 50 nmol/L, n = 23), insufficient (50-75 nmol/L, n = 32), or sufficient (> 75 nmol/L, n = 32). Serum 25-hydroxyvitamin D3 (25[OH]D3) concentration and physical performance were measured perioperatively. Linear mixed models were used to examine differences between groups.

RESULTS

Change in physical performance over time was not affected by preoperative vitamin D status. In contrast, for physical activity, both vitamin D (p = 0.021) and time (p < 0.001) effect was seen: from 80.2 ± 25.8 to 58.1 ± 17.8 min/day in the deficient group, 143.7 ± 19.8 to 92.9 ± 11.5 min/day in the insufficient group, and 108.1 ± 20.9 to 62.3 ± 12.9 min/day in the sufficient group. The Chair Stand Test, Timed Up and Go test, and 10-Meter Walking Test also improved significantly over time, but independent of vitamin D status. An increase in 25(OH)D3 concentration 6 weeks postoperatively was correlated with improved hip function (Pearson's r = -0.471, p = 0.018). Overall, serum 25(OH)D3 declined with 32% one day after surgery (p < 0.001), to nearly return to baseline values 6 weeks later in all groups.

CONCLUSION

Vitamin D status did not appear to affect physical recovery after THA. The drop in vitamin D after surgery deserves further investigation, but could possibly be explained by hemodilution.