Understanding rates, risk factors, and complications associated with manipulation under anesthesia after total knee arthroplasty (TKA): An analysis of 100,613 TKAs

The association between losartan potassium prescription and postoperative outcomes following total knee arthroplasty: A TriNetX analysis

BACKGROUND

Total knee arthroplasty (TKA) is a common surgical procedure performed to alleviate pain and improve functional outcomes in patients with knee osteoarthritis and rheumatoid arthritis who have failed conservative treatments. Arthrofibrosis has been extensively studied due to its negative impact on TKA outcomes. Losartan, an angiotensin receptor blocker (ARB), has the potential to improve TKA outcomes by inhibiting TGF-β and decreasing fibrosis. This study aims to analyze a large-scale, real-world healthcare database to investigate the association between losartan potassium prescription and postoperative outcomes such as readmissions, ED visits, and the need for MUA or revision TKA.

HYPOTHESIS

Based on previous literature and the nature of ARBs, it is expected that the addition of losartan will aid in better outcomes for patients following a primary TKA.

PATIENTS AND METHODS

In this retrospective observational study, the TriNetX Research Network (TriNetX) database was queried as of June 21, 2023. All patients who underwent a primary total knee arthroplasty (TKA) prior to June 21, 2022 were included. Patients were then divided into two cohorts by whether they had an active losartan potassium prescription within the year prior to their surgery to within 90days postoperatively. Patients were then propensity-matched to eliminate differences in demographics and comorbidities.

RESULTS

Losartan TKA patients were 1.18 [OR: 0.85 (95% CI: 0.79-0.90), p<0.001] times less likely to be readmitted within 90days and were 1.15 (OR: 0.87 (95% CI: 0.79-0.96); p=0.009) times less likely to undergo a manipulation under anesthesia (MUA) within the 1-year postoperative period. There were no statistically significant differences in rates of emergency department (ED) visits at 90days postoperatively or revision TKAs at 1year postoperatively.

DISCUSSION

In conclusion, patients with an active losartan prescription prior to TKA had a significantly lower likelihood of readmission within 90days and a lower likelihood of undergoing MUA within the 1-year postoperative period compared to patients not taking losartan. This presents an opportunity for further clinical investigation to explore the value of losartan in TKA.

LEVEL OF EVIDENCE

III; an observational cohort study.

Outcomes of Early Versus Delayed Manipulation Under Anesthesia for Stiffness Following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Stiffness following total knee arthroplasty (TKA) is often treated with manipulation under anesthesia (MUA). However, there is debate regarding the timing of MUA, with many recommending against MUA beyond 3 months after TKA. Therefore, the purpose of this systematic review was to evaluate the functional and clinical outcomes of early versus delayed MUA for stiffness following TKA.

METHODS

A search following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines was performed in the PubMed, Embase, Scopus, and Cochrane databases in November 2023. Data regarding study characteristics, demographics, knee flexion and extension, patient-reported outcomes, complications, and revisions were collected. A quality assessment was performed using the Methodological Index for Non-randomized Studies. Included were 14 studies analyzing 13,445 knees, 72.1% of which underwent early MUA and 27.8% of which underwent delayed MUA. Of the 14 studies, 10 defined early MUA as being performed within 3 months of the index TKA.

RESULTS

Pre-MUA and post-MUA knee flexion for the early/delayed groups was 71.3°/77.9° and 103.0°/96.1°, respectively. Upon meta-analysis, pre-MUA knee flexion was significantly higher in the delayed group (P = .003), whereas post-MUA flexion was similar in both groups (P = .36). The mean gain in knee flexion for the early and delayed groups was 32.0°/19.2°. The surgical complication and revision TKA rates for the early and delayed groups were 4.9%/10.3% and 5%/9%, respectively. A meta-analysis found the risk of surgical or medical complications and revision TKA to be significantly higher in the delayed MUA group (P < .00001 and = .002, respectively).

CONCLUSIONS

Although post-MUA knee flexion was similar in patients undergoing early and delayed MUA following TKA, the mean gain in flexion for early patients was nearly double that of delayed patients. Delayed patients also had significantly higher risks of surgical or medical complications and revision TKA following MUA.

Arthrofibrosis After Total Knee Arthroplasty: A Critical Analysis Review

» Arthrofibrosis after total knee arthroplasty (TKA) is the new formation of excessive scar tissue that results in limited ROM, pain, and functional deficits.» The diagnosis of arthrofibrosis is based on the patient's history, clinical examination, absence of alternative diagnoses from diagnostic testing, and operative findings. Imaging is helpful in ruling out specific causes of stiffness after TKA. A biopsy is not indicated, and no biomarkers of arthrofibrosis exist.» Arthrofibrosis pathophysiology is multifactorial and related to aberrant activation and proliferation of myofibroblasts that primarily deposit type I collagen in response to a proinflammatory environment. Transforming growth factor-beta signaling is the best established pathway involved in arthrofibrosis after TKA.» Management includes both nonoperative and operative modalities. Physical therapy is most used while revision arthroplasty is typically reserved as a last resort. Additional investigation into specific pathophysiologic mechanisms can better inform targeted therapeutics.