Real-world 2-year clinical and economic outcomes among patients receiving a medial collared, triple tapered primary hip system versus other implants for total hip arthroplasty

OBJECTIVE

To evaluate real-world outcomes of patients receiving ACTIS, a medial collared, triple-tapered (MCTT) hip system vs. other implants, for primary total hip arthroplasty (THA).

METHODS

Patients with THA between 2016-2021 from Mercy Healthcare Systems-Orthopedics Database were evaluated. The primary outcome was the 2-year revision. Secondary outcomes included operating room (OR) time, length of stay (LOS), and discharge disposition. Fine Stratification and Weighting (FSW) controlled for baseline characteristic differences between ACTIS and other implant groups. Cox proportional regression evaluated the hazard ratio (HR) for revision.

RESULTS

Among 9,225 patients with 10,205 THAs (mean [SD] age 66.8 [11.3] years, 56.0% female), MCTT was implanted in 1,591 hips and other implants in 8,614 hips. The balanced cohort included all 10,205 procedures (54.2% female; age 65.5 [11.3]; 14.1% Elixhauser index ≥5; 84.5% MCTT, 82.2% other since 2018; obesity 43.6% MCTT, 43.0% other). Two-year revision was 0.9% for MCTT and 1.8% for other implants (p = .021). HR for revision MCTT vs. other was 0.53 (95% CI 0.30-0.92; p = .023). Mean (SD) OR time was 69.07 (18.93) minutes for MCTT, 83.69 (43.88) for other implants (p < .001). LOS was 1.99 (1.15) days for MCTT, 2.45 (2.91) for other implants (p < .001). MCTT patients were more likely to be discharged home (90.7% vs 33.8%, p < .001) and less likely to be discharged to skilled nursing facilities (SNF) (4.2% vs 9.6%, p < .001). One-year cost savings per patient with MCTT was projected at $2,342.

CONCLUSIONS

MCTT patients had fewer revisions, reduced OR time, shorter LOS, more home and less SNF discharge, leading to cost savings.

Total knee arthroplasty in the outpatient vs inpatient settings: impact of site of care on early postoperative economic and clinical outcomes

BACKGROUND

The incidence of total knee arthroplasty (TKA) surgery performed in the outpatient setting has increased as a result of improved perioperative recovery protocols, bundled payments, and challenges brought by the coronavirus disease of 2019 (COVID-19) pandemic on health systems. This study evaluates early postoperative clinical and economic outcomes of patients treated in the inpatient vs outpatient setting using the Attune Knee System (AKS).

METHODS

Patients with an elective, primary TKA implanted with the AKS, from Q4 2015 to Q1 2021, were identified within the Premier Healthcare Database. The index was defined as the admission date for inpatient cases and the service day for outpatient procedures. Inpatient and outpatient cases were matched on patient characteristics. Outcomes included 90-day all-cause readmissions, 90-day knee reoperations, and index- and 90-day costs of care. Generalized linear models were used to evaluate outcomes (Reoperation: binomial distribution; costs: Gamma distribution with log link).

RESULTS

Before matching, 39,337 inpatient and 9,365 outpatient cases were identified, with greater comorbidities in the inpatient cohort. The outpatient cohort had a lower average Elixhauser Index (EI) compared to the inpatient cohort (1.94 (standard deviation (SD): 1.46) vs 2.17 (SD: 1.53), p < 0.001), and the rates for each individual comorbidities were also slightly lower in the outpatient compared to the inpatient cohorts. Post-match, 9,060 patients were retained in each cohort [mean age: ~ 67, EI = 1.9 (SD: 1.5), 40% male]. Post-match comorbidity rates were similar between inpatient and outpatient cohorts (outpatient EI: 1.94 (SD: 1.44)-inpatient EI: 1.96 (SD: 1.45), p = 0.3516): in both, 54.1% of patients had an EI between 1 and 2, and 5.1% had an EI ≥ 5. No differences were observed in 3-month reoperation rates (0.6% in outpatient, 0.7% in inpatient cohort). Index and post-index 90-day costs were lower in the outpatient vs inpatient cases [(savings for index-only costs: $2,295 (95% CI: $1,977-$2,614); 90 days post-index knee-related care only: $2,540 (95% CI: $2,205-$2,876); 90 days post-index all-cause care: $2,679 (95% CI: $2,322-$3,036)].

CONCLUSIONS

Compared to matched inpatient cases, outpatient TKA cases treated with AKS showed similar 90-day outcomes, at lower cost.

Treatment patterns and clinical and economic burden of hip dislocation following primary total hip arthroplasty in England

Aims

The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England.

Methods

This retrospective evaluation used data from the UK Clinical Practice Research Datalink database. Patients were eligible if they underwent a primary THA (index date) and had medical records available 90 days pre-index and 180 days post-index. Bilateral THAs were excluded. Healthcare costs and resource use were evaluated over two years. Changes (pre- vs post-THA) in generic quality of life (QoL) and joint-specific disability were evaluated. Propensity score matching controlled for baseline differences between patients with and without THA dislocation.

Results

Among 13,044 patients (mean age 69.2 years (SD 11.4), 60.9% female), 191 (1.5%) had THA dislocation. Two-year median direct medical costs were £15,333 (interquartile range (IQR) 14,437 to 16,156) higher for patients with THA dislocation. Patients underwent revision surgery after a mean of 1.5 dislocations (1 to 5). Two-year costs increased to £54,088 (IQR 34,126 to 59,117) for patients with multiple closed reductions and a revision procedure. On average, patients with dislocation had greater healthcare resource use and less improvement in EuroQol five-dimension index (mean 0.24 (SD 0.35) vs 0.44 (SD 0.35); p < 0.001) and visual analogue scale (0.95 vs 8.85; p = 0.038) scores, and Oxford Hip Scores (12.93 vs 21.19; p < 0.001).

Conclusion

The cost, resource use, and QoL burden of THA dislocation in England are substantial. Further research is required to understand optimal timing of revision after dislocation, with regard to cost-effectiveness and impact on QoL.

Cite this article: Bone Joint J 2022;104-B(7):811–819.

The assessment of muscle fatigue in orthopedic surgeons, by comparing manual versus automated broaching in simulated total hip arthroplasty

Total hip arthroplasty procedures are physically demanding for surgeons. Repetitive mallet swings to impact a surgical handle (impactions), can lead to muscle fatigue, discomfort, and injuries. The use of an automated surgical hammer may reduce fatigue and increase surgical efficiency. The aim of this study was to compare the effect of repeated manual and automated impactions on the user's muscle activation, by means of surface electromyography. Surface electromyography signals were recorded from eight muscles of seven (n = 7) orthopedic surgeons during repetitions of manual and automated impactions, to reach the same surgical outcome (broaching depth). Qualitative data was also captured to track the perceived fatigue and preferences of impaction modalities after completion of impaction tasks. Time to complete tasks, muscle activation, and muscle fatigue were quantified. Results showed a significant decrease in time required to reach the same broaching depth for the automated method compared to manual impactions (p = 0.001). A reduction in muscle fatigue and activation of right Brachioradialis muscle was observed during automated impactions (p = 0.018). A significant difference in fatigue was observed, with lower level of fatigue during automated impactions (p = 0.001). These results suggest that an automated surgical workflow might reduce the exposure to the impaction task and, therefore, muscle fatigue, with a reduced activation of the most engaged muscles. The study suggests that the burden on the user can be reduced by a change in the surgical methodology to perform broaching in total hip arthroplasty, which could potentially benefit surgical efficiency and reduce the risk of fatigue-based errors during a procedure.

Healthcare resource utilization and costs for hip dislocation following primary total hip arthroplasty in the medicare population

AIM

To estimate 2-year healthcare resource utilization (HCRU) and costs of dislocation following primary total hip arthroplasty (THA).

MATERIALS AND METHODS

This retrospective evaluation used medical claims from the US Medicare database. Patients were eligible if they were ≥65 years old, underwent a primary elective inpatient THA between 1 January 2010 and 31 December 2016 (index), and had continuous Medicare coverage and enrollment ≥365 days prior to index (baseline). Exclusion criteria were prior THA, concomitant infection, non-Medicare primary payer, or enrolled in Medicare due to end-stage renal disease. One- and 2-year HCRU and costs across all service types and settings of care excluding retail pharmacy were evaluated. Propensity score matching and direct matching adjusted for confounding.

RESULTS

Among Medicare patients who underwent THA and met inclusion criteria (n = 450,355; mean age ∼74, and two-thirds female), 7,680 (1.7%) had a hip dislocation. After matching, 4,551 patients without and 4,551 patients with dislocation were selected. Percentage utilization, mean days of service, and claims payments amounts were significantly greater for patients with vs without THA dislocation for variables such as THA hospitalization, home health agency, skilled nursing facility, inpatient rehabilitation facility, other inpatient admission, long-term care hospital, and outpatient care. Findings were consistent for 1- and 2-year follow-up, although differences were more pronounced for 1-year. Per-patient-cost increases with dislocation were $19,590 over 1 year and $24,211 over 2 years. Two-thirds of the cost increase was due to other inpatient admission and the remaining one-third was due to skilled nursing facility, outpatient, inpatient rehabilitation facility, and home health agency costs.

LIMITATIONS

Administrative claims are not collected for research and lack clinical information. Results may not be generalizable to other patients or settings of care.

CONCLUSIONS

This large US retrospective database study demonstrated the substantial HCRU and cost burden of THA dislocation.

Standard table direct anterior approach within an early discharge protocol for cementless total hip arthroplasty: experience from a Japanese hospital

AIMS

Clinical and economic outcomes associated with an early discharge protocol for cementless total hip arthroplasty (THA) via a direct anterior approach (DAA) on a standard table without a dedicated traction table) were assessed. These outcomes were compared against a benchmark of THA care approximated from a national database.

MATERIALS AND METHODS

This retrospective, observational, comparative cohort study evaluated 250 patients receiving THA with a standard table DAA approach under an early discharge protocol at a medical center in Japan between 2016 and 2017 (intervention). Patients were propensity score-matched to a standard care control group comprised of THA patients within the Japan Medical Data Center database. A generalized linear model (GLM) using gamma distribution with log-link compared hospital length of stay (LOS) and total cost. Post-operative function and pain (Japanese Orthopaedic Association hip score [JOA] and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire [JHEQ]) were assessed for DAA patients.

RESULTS

After propensity score matching, 239 patients were included in each cohort. The patients in the intervention and control group were comparable in regard to age, gender, comorbidities, and procedure year. Adjusted hospital LOS for DAA as part of an early discharge protocol was significantly shorter than for control patients (4.76 vs. 25.36 days). Adjusted total costs were significantly lower (29%) for the intervention group (¥1,613,800 vs. ¥2,254,757; US$14,390 vs. US$20,105). The 3-month follow-up complication rate was 0.42% (superficial infection) for intervention vs. 3.35%. The intervention group had no readmissions and post-operative function and pain scores significantly improved (JHEQ pain score 7.2 ± 5.0 to 24.2 ± 4.6, JOA 48.4 ± 12.8 to 94.3 ± 7.0; p-value < .001).

LIMITATIONS

The study is not randomized and EMR and administrative claims data may lack information (i.e. some clinical variables) required for inference. Also, the data may not represent the whole Japanese population.

CONCLUSIONS

An early discharge protocol demonstrated compatibility with standard table DAA in a Japanese hospital, providing cost savings, while maintaining reliable clinical outcomes.

Survival analysis for all-cause revision following primary total hip arthroplasty with a medial collared, triple-tapered primary hip stem versus other implants in real-world settings

OBJECTIVE

Patients that undergo total hip replacement (THA) are at risk of revision surgery. This study evaluated the cumulative incidence of revision following a medial collared, triple tapered (MCTT) primary hip stem versus other implants in real-world settings using electronic medical records.

METHODS

This was a retrospective cohort study that used the Mercy Healthcare Systems - Orthopedics Database (MHSOD) to identify ACTIS total hip system, a MCTT primary hip stem for THA, and any other primary THA between 2016 and 2020. A Kaplan-Meier analysis was conducted to evaluate the risk of revision over time between the MCTT hip stem and other implants. In order to control for the confounding, a multivariable Cox model was developed to evaluate the risk of revision between the two groups.

RESULTS

There were 1213 patients treated with MCTT hip stem and 6916 patients treated with other implants. The Kaplan-Meier analysis showed statistically significant difference (p value = .006) in cumulative incidences for all-cause revisions between the MCTT hip stem and other implants. The cumulative incidence at 3 years was 1.08% (0.43-2.72%) for the MCTT hip stem, while it was 2.63% (2.19-3.16%) for other implants. After adjusting for patient demographics, clinical characteristics, prescribed medications, and surgeon characteristics, the multivariable Cox proportional hazard model showed the MCTT hip stem was statistically significantly associated with 57% lower risk of revisions compared with other implants (HR, 0.43; 95% CI, 0.19-0.97; p-value = .042).

CONCLUSIONS

This real-world study found that the incidence of revision after treatment with MCTT primary hip stem was significantly lower than for other implants.

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

This study assessed the impact of intraoperative and early postoperative periprosthetic hip fractures (PPHFx) after primary total hip arthroplasty (THA) on health care resource utilization and costs in the Medicare population.This retrospective observational cohort study used health care claims from the United States Centers for Medicare and Medicaid Standard Analytic File (100%) sample. Patients aged 65+ with primary THA between 2010 and 2016 were identified and divided into 3 groups - patients with intraoperative PPHFx, patients with postoperative PPHFx within 90 days of THA, and patients without PPHFx. A multi-level matching technique, using direct and propensity score matching was used. The proportion of patients admitted at least once to skilled nursing facility (SNF), inpatient rehabilitation facility (IRF), and readmission during the 0 to 90 or 0 to 365 day period after THA as well as the total all-cause payments during those periods were compared between patients in PPHFx groups and patients without PPHFx.After dual matching, a total 4460 patients for intraoperative and 2658 patients for postoperative PPHFx analyses were included. Utilization of any 90-day post-acute services was statistically significantly higher among patients in both PPHFx groups versus those without PPHFx: for intraoperative analysis, SNF (41.7% vs 30.8%), IRF (17.7% vs 10.1%), and readmissions (17.6% vs 11.5%); for postoperative analysis, SNF (64.5% vs 28.7%), IRF (22.6% vs 7.2%), and readmissions (92.8% vs 8.8%) (all P < .0001). The mean 90-day total all-cause payments were significantly higher in both intraoperative ($30,114 vs $21,229) and postoperative ($53,669 vs $ 19,817, P < .0001) PPHFx groups versus those without PPHFx. All trends were similar in the 365-day follow up.Patients with intraoperative and early postoperative PPHFx had statistically significantly higher resource utilization and payments than patients without PPHFx after primary THA. The differences observed during the 90-day follow up were continued over the 1-year period as well.

Intravenous xenon- 133 for the determination of radionuclide first pass right ventricular ejection fraction

The use of intravenous xenon- 133 for determination of radionuclide first pass right ventricular ejection fraction is described. First pass determinations of right ventricular ejection fraction were made with both xenon- 133 and technetium-99m in 13 subjects (15 right ventricular ejection fraction determinations); results obtained with xenon- 133 show an excellent correlation (r = 0.98, p less than 0.002) with results obtained using technetium-99m. Because of rapid pulmonary elimination of xenon- 133 from the body, the use of this radioisotope allows multiple first pass right ventricular ejection fraction determinations within a short period of time, without significant radiation exposure for the patient.

X-ray depth-dose characteristics of the Toshiba LMR-16

The depth-dose characteristics of the Toshiba LMR-16 linear accelerator for 14-MeV x rays have been measured at an SSD of 100 cm using diodes and ion chambers. The surface dose and build-up depth both exhibit a considerable variation with field size. A new central axis model has been developed which takes account of these variations, and the agreement between the measured and computed data using this model is found to be excellent. Formulas are also presented to estimate the surface dose, buildup depth, and output factor as a function of field size.

Determination and importance of the magnification factor in the calculation of ventricular volume: development of a simple, accurate method

A study of single-plane right anterior oblique left ventricular angiography was undertaken to determine the importance of obtaining correct positioning of a magnification grid and to develop a simple but accurate technique to minimize magnification errors. Theoretical and experimental volume determinations demonstrated 3% to 28% volume errors for grid placement errors ranging from 1 centimeter to 5 centimeters. An experiment was designed whereby cross table lateral radiographs of the chest were taken during contrast injections of the left ventricle. The relative position of the left ventricular center was found at a point 66% of the distance from the anterior to the posterior margin of the heart. Finding this point on noncontrast lateral films of the chest for positioning of a square centimeter grid should yield a more accurate determination of the magnification factor than other current emperic methods.

A data acquisition system for three-dimensional treatment planning

The authors describe a coordinate measuring device developed to simplify manual acquisition of the digital information required for computerized three-dimensional treatment planning. This system has been used for two years and shown to be both fast and accurate. The time needed to digitize contour data is reduced to approximately one-tenth of that required for manual methods in most cases.