Medical resource utilization and costs for intraoperative and early postoperative periprosthetic hip fractures following total hip arthroplasty in the medicare population: A retrospective cohort study

What are the predisposing factors for periprosthetic fractures following total hip arthroplasty? - a National Inpatient Sample-based study

INTRODUCTION

With a progressive rise in the number of total hip arthroplasties (THA) over the past decades, the proportion of patients sustaining peri-prosthetic fractures (PPF) has been substantially increasing. In this context, the need for clearly understanding the factors predisposing patients to PPF following THA and the impact of these adverse complications on the overall healthcare burden cannot be understated.

MATERIALS AND METHODS

Based upon the Nationwide Inpatient Sample (NIS) database, the patients who underwent THA in the United States between 2016 and2019 (with ICD-10 CMP code) were identified. The patients were divided into 2 groups; group A - patients who sustained PPF and group B - those who did not. The information about the patients' demographic profile, medical comorbidities; and hospital admission (including length of stay and expenditure incurred) were analysed; and compared between the 2 groups.

RESULTS

Overall, 367,890 patients underwent THA, among whom 4,425 (1.2%) sustained PPF (group A). The remaining patients were classified under group B (363,465 patients). On the basis of multi-variate analysis (MVA), there was a significantly greater proportion of females, elderly patients, and emergent admissions (p < 0.001) in group A. The length of hospital stay, expenditure incurred and mortality were also significantly higher (p = 0.001) in group A. Based on MVA, Down's syndrome (odd's ratio 3.15, p = 0.01), H/O colostomy (odd's ratio 2.09, p = 0.008), liver cirrhosis (odd's ratio 2.01, p < 0.001), Parkinson's disease (odd's ratio 1.49, p = 0.004), morbid obesity (odd's ratio 1.44, p < 0.001), super obesity (odd's ratio 1.49, p = 0.03), and H/O CABG (coronary artery bypass graft; odd's ratio 1.21, p = 0.03) demonstrated significant association with PPF (group A).

CONCLUSION

Patients with PPF require higher rates of emergent admission, longer hospital stay and greater admission-related expenditure. Female sex, advanced age, morbid or super obesity, and presence of medical comorbidities (such as Down's syndrome, cirrhosis, Parkinson's disease, previous colostomy, and previous CABG) significantly enhance the risk of PPF after THA. These medical conditions must be kept in clinicians' minds and close follow-up needs to be implemented in such situations so as to mitigate these complications.

Are periprosthetic hip fractures more severe than native hip fractures? A systematic review of outcomes and resource utilization

BACKGROUND

There is a paucity of data comparing periprosthetic hip fracture (PPHFx) outcomes and resource utilization to native fractures. Many surgeons consider periprosthetic hip fractures to be more severe injuries than native fractures. The aim of this systematic review is to characterize the outcomes of PPHFx and assess their severity relative to native hip fractures (NHFx).

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analysis systematic review was conducted using Medline, Biosis, and Cinahl. Primary outcomes were time to surgery, length of stay (LOS), cost of management, disposition, complication rates, readmission rates, and mortality.

RESULTS

14 articles (13,489 patients) from 2010 to 2018 were included in the study. Study quality was generally low. Patient follow-up ranged from 1 month to 3.2 years. LOS ranged from 5.2 to 38 days. US cost of management was best estimated at $53,669 ± 19,817. Discharge to skilled nursing facilities ranged from 64.5 to 74.5%. Time to surgery ranged from 1.9 to 5.7 days. Readmission rates ranged from 12 to 32%. Per Clavien-Dindo classification, 33.9% suffered minor complications; 14.3% suffered major complications. 1 month and 1 year mortality ranged from 2.9% to 10% and 9.7% to 45%, respectively.

CONCLUSION

Time to surgery and LOS were longer for PPHFx relative to NHFx. Complications' rates were higher for PPHFx compared to NHFx. There is no evidence for differences in LOS, cost, discharge, readmission rates, or mortality between PPHFx and NHFx. These results may serve as a baseline in future evaluation of PPHFx management.

Age as a Risk Factor for Intraoperative Periprosthetic Femoral Fractures in Cementless Hip Hemiarthroplasty for Femoral Neck Fractures: A Retrospective Analysis

Background

Understanding the risk factors and outcomes of intraoperative periprosthetic femoral fractures (IPFF) during hip arthroplasty is crucial for appropriate perioperative management. Previous studies have identified risk factors for IPFF in total hip arthroplasty patients, but data for hip hemiarthroplasty (HA) is lacking. The aim of this study was to determine the age associated with increased rates of IPFF in patients undergoing HA.

Methods

We retrospectively reviewed patients aged 65 years and above who underwent a cementless HA for a displaced femoral neck fracture and had a minimum of 1-year follow-up. Patients were stratified into five age groups (65-79, 80-84, 85-89, 90-94, and ≥ 95 years) and further divided into two subgroups (under 95 years and 95 years or older). The presence, location, and treatment of IPFF, as well as the effect of IPFF on the postoperative weight-bearing status, were compared between groups. A multivariate logistic regression was also performed. A total of 1,669 met the inclusion criteria and were included in the study.

Results

The rates of IPFF were significantly higher for patients 95 years or older (p = 0.030). However, fracture location (greater trochanter fractures, p = 0.839; calcar fractures, p = 0.394; and femoral shaft fractures p = 0.110), intraoperative treatment (p = 0.424), and postoperative weight-bearing status (p = 0.229) were similar between the groups. While mortality and nonorthopedic-related readmissions were significantly higher for patients 95 years or older, orthopedic-related readmissions (p = 0.148) and revisions at the latest follow-up (p = 0.253) were comparable between groups. In a regression analysis, age over 95 years (odds ratio, 2.049; p = 0.049) and body mass index (odds ratio, 0.935; p = 0.016) were independently associated with IPFF.

Conclusions

The findings of this study suggest that age over 95 years is a significant, independent risk factor for IPFF in patients undergoing cementless HA. Although we were unable to show an impact on perioperative outcomes and orthopedic complications, when operating on patients 95 years or older, surgeons should be aware of the increased risk of IPFF and consider the use of stem designs and fixation types associated with decreased IPFF rates.

CT required to perform robotic-assisted total hip arthroplasty can identify previously undiagnosed osteoporosis and guide femoral fixation strategy

Osteoporosis can determine surgical strategy for total hip arthroplasty (THA), and perioperative fracture risk. The aims of this study were to use hip CT to measure femoral bone mineral density (BMD) using CT X-ray absorptiometry (CTXA), determine if systematic evaluation of preoperative femoral BMD with CTXA would improve identification of osteopenia and osteoporosis compared with available preoperative dual-energy X-ray absorptiometry (DXA) analysis, and determine if improved recognition of low BMD would affect the use of cemented stem fixation. Retrospective chart review of a single-surgeon database identified 78 patients with CTXA performed prior to robotic-assisted THA (raTHA) (Group 1). Group 1 was age- and sex-matched to 78 raTHAs that had a preoperative hip CT but did not have CTXA analysis (Group 2). Clinical demographics, femoral fixation method, CTXA, and DXA data were recorded. Demographic data were similar for both groups. Preoperative femoral BMD was available for 100% of Group 1 patients (CTXA) and 43.6% of Group 2 patients (DXA). CTXA analysis for all Group 1 patients preoperatively identified 13 osteopenic and eight osteoporotic patients for whom there were no available preoperative DXA data. Cemented stem fixation was used with higher frequency in Group 1 versus Group 2 (28.2% vs 14.3%, respectively; p = 0.030), and in all cases where osteoporosis was diagnosed, irrespective of technique (DXA or CTXA). Preoperative hip CT scans which are routinely obtained prior to raTHA can determine bone health, and thus guide femoral fixation strategy. Systematic preoperative evaluation with CTXA resulted in increased recognition of osteopenia and osteoporosis, and contributed to increased use of cemented femoral fixation compared with routine clinical care; in this small study, however, it did not impact short-term periprosthetic fracture risk.

Undetected Intraoperative Periprosthetic Femoral Fractures in Patients Undergoing Primary Total Hip Arthroplasty: A Retrospective Case Series and Literature Review

OBJECTIVE

Periprosthetic fracture in total hip arthroplasty (THA) can be catastrophic, and early detection and appropriate management are vital to the overall prognosis. This study aimed to describe and summarize the features of undetected intraoperative periprosthetic femoral fractures (IPFFs) in primary THA patients and treatment measures and to review the relevant literature.

METHODS

We reviewed a total of 6350 primary THAs performed at our institution between January 2013 and December 2020 and screened all IPFFs. Of 138 IPFFs, 24 were undetected and met the inclusion criteria. We recorded and compared basic patient and operative information and measured some parameters to evaluate canal morphologies based on preoperative radiographs. We also compared fracture line characteristics using postoperative radiographs to summarize the features of intraoperative fractures and propose treatment strategies. The Kolmogorov-Smirnov test was used to test the normality of the variable distributions. Measured parameters in all groups were analyzed using one-way analysis of variance and compared using Dunnett's test. The χ² and Fisher exact tests were used to compare reoperation rates across the groups. Interrater and intrarater reliability were evaluated by intraclass correlation coefficients.

RESULTS

Among the 24 hips, there was no significant difference in patient demographics, basic operative information or morphology. The incidence of IPFFs in primary THA patients was 2.17%, and up to 17.4% of IPFFs were undetected until postoperative fluoroscopy. The incidence of undetected IPFFs among all primary THA patients was 0.38% and varied by stem type, with the highest incidence in femurs with either anatomical (1.04%, 4/385) or modular stems (0.90%, 9/1003). Femurs with anatomical stems had a higher reoperation rate. The distal periprosthetic (Gruen zone 4) fracture line of femurs with tapered stems was more prone to involve the medial or lateral bone cortex, which could cause instability.

CONCLUSION

An undetected IPFF is most likely in femurs fitted with a prosthesis of an inappropriate size or type. Anatomical stems will most likely cause unstable fractures; thus, it is recommended to use them with caution and note the possibility of medial distal femoral fracture. Improper modular stem type or size selection results in longitudinal fractures of the distal femur, and prophylactic cerclage wire binding is recommended in dysplastic hips. Incorrect use of tapered stems in well-ossified femurs may cause distal femoral fractures involving the medial or lateral bone cortex. Intraoperative fluoroscopy after implantation may help detect hidden fractures.

Management of Periprosthetic Acetabular Fractures: A Critical Analysis and Review of the Literature

➢

Periprosthetic acetabular fractures are uncommon and infrequently the focus of studies.

➢

Acetabular fractures are occasionally recognized postoperatively when patients report unremitting groin pain weeks after surgery.

➢

The widespread use of cementless acetabular cups might lead to a higher number of fractures than are clinically detectable.

➢

Appropriate recognition, including mindfulness of preoperative patient and surgical risk factors, is critical to the successful management of acetabular complications.

Is the Direct Anterior Approach to THA Cost-effective? A Markov Analysis

BACKGROUND

The use of the direct anterior approach, a muscle-sparing technique for THA, has increased over the years; however, this approach is associated with longer procedure times and a more expensive direct cost. Furthermore, studies have shown a higher revision rate in the early stages of the learning curve. Whether the clinical advantages of the direct anterior compared with the posterior approach-such as less soft tissue damage, decreased short-term postoperative pain, a lower dislocation rate, decreased length of stay in the hospital, and higher likelihood of being discharged home-outweigh the higher cost is still debatable. Determining the cost-effectiveness of the approach may inform its utility and justify its use at various stages of the learning curve.

QUESTIONS/PURPOSES

We used a Markov modeling approach to ask: (1) Is the direct anterior approach more likely to be a cost-effective approach than the posterior approach over the long-term for more experienced or higher volume hip surgeons? (2) How many procedures does a surgeon need to perform for the direct anterior approach to be a cost-effective choice?

METHODS

A Markov model was created with three health states (well-functioning THA, revision THA, and death) to compare the cost-effectiveness of the direct anterior approach with that of the posterior approach in five scenarios: surgeons who performed one to 15, 16 to 30, 31 to 50, 51 to 100, and more than 100 direct anterior THAs during a 6-year span. Procedure costs (not charges), dislocation costs, and fracture costs were derived from published reports, and model was run using two different cost differentials between the direct anterior and posterior approaches (USD 219 and USD 1800, respectively). The lower cost was calculated as the total cost differential minus pharmaceutical and implant costs to account for differences in implant use and physician preference regarding postoperative pain management. The USD 1800 cost differential incorporated pharmaceutical and implant costs. Probabilities were derived from systematic review of the evidence as well as from the Australian Orthopaedic Association National Joint Replacement Registry. Utilities were estimated from best available literature and disutilities associated with dislocation and fracture were incorporated into the model. Quality of life was expressed in quality-adjusted life years (QALYs), which are calculated by multiplying the utility of a health state (ranging from 0 to 1) by the duration of time in that health state. The primary outcome measure was the incremental cost-effectiveness ratio, or the change in costs divided by the change in QALYs when the direct anterior approach was used for THA. USD 100,000 per quality-adjusted life years was used as a threshold for willingness to pay. One-way and probabilistic sensitivity analyses were performed for the scenario in which the direct anterior approach is cost-effective to further account for uncertainty in model inputs.

RESULTS

At a cost differential of USD 219 (95% CI 175 to 263), the direct anterior approach was associated with lower cost and higher effectiveness compared with the posterior approach for surgeons with an experience level of more than 100 operations during a 6-year span. At a cost differential of USD 1800 (95% CI 1440 to 2160), the direct anterior approach remained a cost-effective strategy for surgeons who performed more than 100 operations. At both cost differentials, the direct anterior approach was not cost-effective for surgeons who performed fewer than 100 operations. One-way sensitivity analyses revealed the model to be the most sensitive to fluctuations in the utility of revision THA, probability of revision after the posterior approach THA, probability of dislocation after the posterior approach THA, fluctuations in the probability of dislocation after direct anterior THA, cost of direct anterior THA, and probability of intraoperative fracture with the direct anterior approach. At the cost differential of USD 219 and for surgeons with a surgical experience level of more than 100 direct anterior operations, the direct anterior approach was still the cost-effective strategy for the entire range of values.

CONCLUSION

For high-volume hip surgeons, defined here as surgeons who perform more than 100 procedures during a 6-year span, the direct anterior approach may be a cost-effective strategy within the limitations imposed by our analysis. For lower volume hip surgeons, performing a more familiar approach appears to be more cost-effective.

Diagnosis and Management of Intraoperative Fractures in Primary Total Hip Arthroplasty

Intraoperative periprosthetic fractures are challenging complications that may affect implant stability and survivorship. Periprosthetic acetabular fractures are uncommon and infrequently are the focus of studies. Acetabular fractures are occasionally recognized after patients report unremitting groin pain weeks postoperatively. The widespread use of cementless acetabular cups might lead to higher number of fractures than is clinically detectable. Conversely, the incidence of intraoperative periprosthetic femoral fractures are more common and encompass a broad spectrum, ranging from a small cortical perforation to displaced fractures with an unstable prosthesis. Appropriate recognition, including mindfulness of preoperative patient and surgical risk factors, is critical to the successful management of acetabular and femoral complications. This comprehensive review article focuses on the incidence, patient and surgical risk factors, diagnosis, management, and clinical outcomes associated with intraoperative acetabular and femur fractures in primary total hip arthroplasty.