Epidemiology of primary and revision total knee arthroplasty: analysis of demographics, comorbidities and outcomes from the national inpatient sample

Abstract

Introduction Primary total knee arthroplasty (TKA) is a preferred treatment for end-stage knee osteoarthritis. In the setting of a failed TKA, revision total knee arthroplasty (rTKA) acts as a salvage procedure and carries a higher risk compared to primary TKA. Given increased interest in postoperative outcomes from these procedures, a thorough understanding of the demographics, comorbidities, and inpatient outcomes is warranted. This study aimed to report the epidemiological data of demographics, comorbidity profiles and outcomes of patients undergoing TKA and rTKA. Methods A retrospective review of NIS registry discharge data from 2006 to 2015 third quarter was performed. This study included adults aged 40 and older who underwent TKA or rTKA. A total of 5,901,057 TKA patients and 465,968 rTKA patients were included in this study. Simple descriptive statistics were used to present variables on demographics, medical comorbidities, and postoperative complications. Results A total of 5,901,057 TKA and 465,968 rTKA discharges were included in this study, with an average age of 66.30 and 66.56 years, and the major payor being Medicare, accounting for 55.34% and 59.88% of TKA and rTKA cases, respectively. Infection (24.62%) was the most frequent reason for rTKA, and was followed by mechanical complications (18.62%) and dislocation (7.67%). The most common medical comorbidities for both groups were hypertension, obesity, and diabetes. All types of inpatient complications were reported in 22.21% TKA and 28.78% of rTKA cases. Postoperative anemia was the most common complication in both groups (20.34% vs. 25.05%). Conclusions Our data demonstrated a 41.9% increase in patients receiving TKA and 28.8% increase in rTKA from the years 2006 to 2014. The data showed a 22.21% and a 28.78% “complication” rate with TKA and rTKA, with postoperative anemia being the most common complication. The top 3 medical comorbidities were hypertension, obesity, and diabetes for both groups and with increased focus on perioperative optimization, future analyses into preoperative medical optimization, and improved primary arthroplasty protocol may result in improved postoperative outcomes.

Cardiovascular Disease in Total Knee Arthroplasty: An Analysis of Hospital Outcomes, Complications, and Mortality

“…In a review of other NIS studies, Nham et al noted that 3.57% of their TKA cohort had a valvular disorder and 2.48% had CHF. 15) Pugely et al 7) also noted 3.82% and 3.4%, respectively. Both studies proved prevalence, but like much of the current literature, lacked the inclusivity of our study (i.e., CAD and arrhythmia, which composed 75% of our disease prevalence).…”

“… 18) In TKA, this is likely due to inconsistent nomenclature, with studies either referring to it broadly as heart disease or only reporting one diagnosis (i.e., CHF). 3 4 5 6 7 13 14 15 18) This can lead to underestimation and ultimately alter outcome analyses. 18) It is important for surgeons to be aware of the breadth of diagnoses and be consistent in nomenclature to have a more complete understanding of the role of cardiac disease in TKA outcomes.…”

“… 3 5 6 7 9 10) Hospital variables including LOS, total charges, and discharge disposition were obtained. 9 10 11 12 13 14 15) Lastly, perioperative complications were collected. 3 4 5 6 7 8 10 11 12 13 14 15) …”

“… 9 10 11 12 13 14 15) Lastly, perioperative complications were collected. 3 4 5 6 7 8 10 11 12 13 14 15) …”

Posterior tibial slope influences joint mechanics and soft tissue loading after total knee arthroplasty

“…Currently, around 400,000 primary TKA surgeries are conducted annually in the United States alone ( Varacallo et al, 2022 ), and it is anticipated that this number will surge to 1.26 million operations per year by 2030 ( Sloan et al, 2018 ; Shichman et al, 2023 ). Unfortunately, surgery outcome dissatisfaction rates varying from 10% to 30% ( Ayers et al, 2022 ; Ferri et al, 2023 ; Inui et al, 2023 ; Nham et al, 2023 ), with the greatest complaints concerning persistent pain and joint stiffness, which impede subject’s ability to engage in everyday functional activities ( Choi and Ra, 2016 ). Importantly, poor functional and clinical outcomes greatly contribute to revision surgeries, particularly among younger individuals who have undergone TKA (with revision rates of up to 22% for patients undergoing surgery below 50 years ( Stone et al, 2022 )).…”