Simultaneous Versus Staged Knee Arthoplasty? Save

There are an estimated 900,000 knee replacements (TKR) performed in the U.S. every year.  This number is up from 754,000 TKRs in 2017, according to the Agency for Healthcare Research and Quality.

There are currently over 5 million Americans who have undergone TKR. The number of TKAs performed annually in the United States is expected to increase in volume by 143 percent by 2050 compared with 2012.

In 2020, the cost of TKR in the United States ranged between $30,000 and $50,000. Aside from cost, there are significant concerns regarding efficacy and safety outcomes and recovery time. These issues are compounded with the need for bilateral TKR, wherein the patient and surgeon need to decide whether to have both TKRs done simultaneously or staged (single TKR one after another with a recovery period in between).

Simultaneous TKRs have the potential of less hospitalization an OR time, shorter recovery and rehabilitation time, and decreased costs.

The risks and benefits of each approach has been analyzed in numerous comparative reports (simultaneous vs. staged TKRs) based on large center or population data.  Below are several cohort outcomes of Staged vs. Simultaneous TKRs.

• Complication Rates: Richardson et al looked at complications associated with simultaneous versus staged bilateral TKR within 12 months from 7747 undergoing bilateral TKR between 2007 and 2015. The found higher rates of blood transfusion and readmission with simultaneous bilateral TKR, but higher rates of mechanical complications and infection were associated with staged bilateral TKR. 
• Costs: Phillips et al did a retrospective, single center review of  319 simultaneous primary TJAs and 168 staged TJAs (between 2015 and 2016) to examine the 90-day episode-of-care costs among Medicare beneficiaries needing bilateral TKR.  While there were no differences in readmissions, simultaneous TKRs had more thromboembolic events (2% vs 0%, P = .003), and decreased inpatient facility costs ($19,402 vs $23,025, P < .001), but there was no difference in episode of care costs.  
• Satisfaction: A cross sectional study in the J Clin Orthop Trauma looked 3 cohorts having bilateral TKRs between 2009-2016: 1) simultaneous TKR  (n = 272), 2)  staging in the same hospitalization (n=146), and 3) staging in different hospitalizations (n=245). All patients improved and complications were without significant differences between groups.  However, patient satisfaction was significantly higher in the simultaneous TKR group (P = 0.013) and costs were lower.  The risk of venous thromboembolism was increased in  older overweight patients, regardless of group.
• Equal: Sarzaeem et al. compared clinical outcomes of 100 patients with staged vs simultaneous bilateral TKR (2014 to 2017).  The found no statistically significant difference between approaches (looking at numerous outcomes: OKS, WOMAC, SF-36, ROM, postoperative bleeding, and hospitalization duration).  
• Blood Loss: Goyal et al prospectively compared outcomes in 250 simultaneous versus 210 two-staged bilateral TKR patients. For the staged TKR patients the minimum time interval between two operations was three weeks (mean 1.6 months, range 3 weeks-12 months). There was no significant difference between the 2 groups in peri-operative mortality, surgical site infection, major peri-operative complications. There was more post-operative haemoglobin drop and transfusion need in the simultaneous TKR patients, but a significantly longer hospital stay and duration of surgery in the staged TKR group. 
• Return to Work: Kahlenberg looked at return to work outcomes in 152 employed patients undergoing TKR  and showed that employed patients undergoing simultaneous bilateral TKA missed a mean of 17 fewer days of work compared with to staged bilateral TKA.  Bone Joint J . 2021 Jun;103-B(6 Supple A):108-112.
• Metanalysis. Hussain et al performed a meta-analysis comparing simultaneous bilateral with staged bilateral TKR peri-operative complication rates, infection rates and mortality outcomes. From 18 articles, they showed a significantly higher mortality risk in the simultaneous group at 30 days (RR 3.67, [CI] 1.68–8.02), 3 months and 1 year after surgery (RR 1.85, CI 1.66–2.06, p < 0.001). But there were no significant differences between groups for in-hospital mortality, deep vein thrombosis, cardiac complication, and pulmonary embolism or infection rates.  HSS J. 2013 Feb; 9(1): 50–59.