The Cost Effectiveness of Unicompartmental versus Total Knee Arthroplasty.

This study examines the potential cost savings for the health system and the community in a broadly accessible model through the increased utilization of unicompartmental knee arthroplasty (UKA) using robotic arm-assisted UKA (raUKA) versus conventional total knee arthroplasty (cTKA). We retrospectively reviewed 240 patients where the first 120 consecutive raUKA performed during this period were matched to 120 cTKAs. Clinical data from the medical records and costs for procedure for each component were collected. Bivariate analyses were performed on the data to determine if there were statistically significant differences by surgery type in clinical outcomes and financial costs. There was a significantly lower cost incurred for raUKA versus cTKA with an average saving of AU$7,179 per case. The operating time (86.0 vs. 75.9 minutes; p = 0.004) was significantly higher for raUKA, but the length of stay was significantly lower (1.8 vs. 4.8 days; p < 0.001). There was a significant difference in the use of opioids between raUKA and cTKA (125.0 morphine equivalent [ME] vs. 522.1 ME, p < 0.001). This study demonstrated that the use of raUKA rather than cTKA in suitably indicated patients may realize significant cost savings.

Fixation Method for Hip Arthroplasty Stem Following Hip Fracture: A Population-Level Cost-Effectiveness Analysis.

BACKGROUND: Hip arthroplasty is increasing in Australia. The number of procedures for fractured neck of femur was 7500 in 2017. Best practices for fixation method and procedure type require scrutiny. This paper is about the costs and health outcomes of cemented and uncemented hemiarthroplasty and total hip arthroplasty at a national level. METHODS: We created a Markov model for patients <75, aged 75-85, and over 85. Expected costs and health outcomes over 5 years from a decision to change from existing practice to a best practice policy in which all patients with fractured neck of femur received the same fixation method based on age and type of arthroplasty are estimated. The model was populated using prevalence and incidence data from the Australian Orthopedic Association National Joint Replacement Registry, costs from Metro North Hospital and Health Service in Queensland, and probabilities and utilities from the literature. We simulated the uncertainties in outcomes with probabilistic sensitivity analysis. RESULTS: We found that uncemented stem procedures were more costly and provided worse health outcomes compared to cemented stem fixation for hemiarthroplasty and total hip arthroplasty for all age groups. Moving from existing practice to cemented stem arthroplasty could save the Australian health system $2.0 million over 5 years with a gain of 203 quality-adjusted life years. CONCLUSION: We suggest that consideration be given to cemented fixation of the femoral stem for patients receiving both hemiarthroplasty and total hip arthroplasty for fractured neck of femur. Best practice guidelines focused on cost-effectiveness should recommend cemented stem fixation to both save costs and improve patient quality of life.

The use of a 3-dimensional computed tomography bone database to evaluate the risk of distal contact between the rasp tip and the endosteal cortical bone.

PURPOSE: To use a 3-dimensional computed tomography (CT) bone database to evaluate the risk of distal contact between the rasp tip and the endosteal cortical bone. METHODS: Using a 3-dimensional CT bone database, the rasps for Exeter stems of 125 mm in length and body size 1, with a femoral offset of 37.5, 44, or 50 mm were compared with those for Exeter stems of 150 mm in length and same body size with the corresponding femoral offset. Rasp geometry was determined using an engineering drawing software. RESULTS: Of the 631 femurs in the database, 238 (187 Caucasian and 51 Asian) were of appropriate femoral offset and proximal body size to receive a stem with an offset of 37.5, 44, or 50 mm. Of these, 145 (115 Caucasian and 30 Asian) femurs were of champagne-flute type; the prevalence was comparable between the 2 populations (61% vs. 59%, p=0.729). When using the 150-mm rasp, 70 (55 Caucasian and 15 Asian) of the 238 femurs had distal contact between the rasp and femoral cortex; the prevalence was comparable between the 2 populations (29% vs. 29%, relative risk=1.0, p=1.0). Distal contact between the rasp and femoral cortex occurred more commonly in champagne-flute-type femurs than other femurs in the anteroposterior plane (28% [41/145] vs. 2% [2/93], relative risk=13.1, p<0.001) and in the mediolateral plane (27% [39/145] vs. 14% [13/93], relative risk=1.92, p=0.019). When using the 125-mm rasp, only one femur (with a canal flare index of 4.52) had distal contact in the mediolateral plane with an offset of 37.5 mm. Distal contact between the rasp and femoral cortex occurred more often with the 150-mm rasp than the 125-mm rasp in both planes (p<0.001). CONCLUSION: The use of a shorter stem may enhance anatomic fit in patients with a narrow femoral canal and prevent distal contact between the rasp and femoral cortex.

Preoperative assessment of femoral rotation and its relationship with coronal alignment: A magnetic resonance imaging study.

This MRI study explores the individual variation of the rotational axes of the distal femur, and investigate the relationship of this variation with overall coronal alignment in the osteoarthritic knee,The mean surgical epicondylar axis (SEA) was 1.7°, anatomical epicondylar axis (AEA) 5.6° and AP trochlea axis (APA) 94.3° external rotation, compared to the posterior condylar line. Investigating this relationship between different coronal alignment groups, there were statistically significant differences between excessive varus and excessive valgus knees for SEA (0.9:3.0 p < 0.001) and AEA (4.7:7.0 p < 0.001). There was no statistical difference for APA (93.9:95.3 p = 0.238).

Surgical site infection prevention following total hip arthroplasty in Australia: a cost-effectiveness analysis.

BACKGROUND: Surgical site infection (SSI) is associated with substantial costs for health services, reduced quality of life, and functional outcomes. The aim of this study was to evaluate the cost-effectiveness of strategies claiming to reduce the risk of SSI in hip arthroplasty in Australia. METHODS: Baseline use of antibiotic prophylaxis (AP) was compared with no antibiotic prophylaxis (no AP), antibiotic-impregnated cement (AP + ABC), and laminar air operating rooms (AP + LOR). A Markov model was used to simulate long-term health and cost outcomes of a hypothetical cohort of 30,000 total hip arthroplasty patients from a health services perspective. Model parameters were informed by the best available evidence. Uncertainty was explored in probabilistic sensitivity and scenario analyses. RESULTS: Stopping the routine use of AP resulted in over Australian dollars (AUD) $1.5 million extra costs and a loss of 163 quality-adjusted life years (QALYs). Using antibiotic cement in addition to AP (AP + ABC) generated an extra 32 QALYs while saving over AUD $123,000. The use of laminar air operating rooms combined with routine AP (AP + LOR) resulted in an AUD $4.59 million cost increase and 127 QALYs lost compared with the baseline comparator. CONCLUSION: Preventing deep SSI with antibiotic prophylaxis and antibiotic-impregnated cement has shown to improve health outcomes among hospitalized patients, save lives, and enhance resource allocation. Based on this evidence, the use of laminar air operating rooms is not recommended.

The cost-effectiveness of routine follow-up after primary total hip arthroplasty.

Routine postsurgery assessment of primary total hip arthroplasty (THA) is recommended in many countries. Whether the benefits of this activity are justified by the costs is not known. We used a decision-analytic Markov model to compare the costs and health outcomes of 3 different follow-up strategies after primary THA. If there is no routine follow-up of patients for 7 years after primary THA, there would be cost savings between AU$6.5 and $11.9 million and gains of between 1.8 and 8.8 quality-adjusted life years. Policy makers should investigate less resource-intensive alternatives to common routine postsurgical assessment.