# Predictive Factors for Total Knee Arthroplasty: An Observational Study

## TL;DR

This study identifies age, gender, hypertension, and elevated ESR as factors predicting the need for total knee arthroplasty in patients with knee osteoarthritis.

## Contribution

The study provides new insights into specific predictive factors for TKA in KOA patients, particularly highlighting the role of ESR and hypertension.

## Key findings

- Patients requiring TKA were significantly older (65.12 years) compared to others (52.55 years).
- Women were over three times more likely to require TKA than men.
- Elevated ESR was associated with a 26-fold increased likelihood of needing TKA.

## Abstract

Introduction

Knee osteoarthritis (KOA) is the most common form of osteoarthritis. It is diagnosed based on clinical symptoms, physical examination, and imaging, most frequently by knee X-ray in at least two views.

In front of a patient with early KOA, all the predictive factors and risk factors that can be modified, but also that can lead to a rapid evolution of the symptoms and the need for total knee arthroplasty (TKA), must be taken into account and identified. There were a series of prognostic factors associated with KOA, such as age, sex, BMI, degree of physical activity, decrease in bone mineral density, C-reactive protein, malalignment, clinical severity at baseline, and previous traumas.

The treatment of KOA is varied and involves pharmacological and non-pharmacological measures and surgical treatment in the final stages of evolution.

Materials and methods

In the University Emergency Hospital of Bucharest, Bucharest, Romania, patients with KOA presented to the Department of Orthopedics and Traumatology, and those who required surgical treatment, such as TKA, arthroscopy, or non-surgical treatment, were enrolled. We conducted a descriptive and prospective observational study that included 70 patients clinically and imaging diagnosed with KOA. The inclusion criteria consisted of a patient over 45 years old with knee pain and radiological signs of KOA. The exclusion criteria referred to patients with recent traumatic history, signs of active osteoarticular infection, the lack of radiological changes of KOA that imposed the differential diagnosis, patients known to have rheumatological diseases in the Algic phase, and patients in whom it was not possible to collect complete required data.

Results

Patients who required TKA were older (65.12 ± 8.19 years) than patients who required other therapeutic interventions (52.55 ± 3.63 years), the difference of 12.57 years being statistically significant (t = −8.882, p ≤ 0.001). Women were more than three times more likely to require TKA than men (80.85% vs. 52.17%, OR = 3.87, CI [1.29, 11.56]). Patients with HBP were more than four times more likely to require TKA than patients without HBP (78.57% vs. 42.86%, OR = 4.88, CI [1.42, 16.82]). Patients with elevated ESR were more than 26 times more likely to require TKA than patients with normal ESR (96.67% vs. 52.50%, OR = 26.23, CI [3.25, 211.67]). There are statistically significant differences between the non-TKA group (mean rank = 60.20) and TKA patients’ score (mean rank = 25.62) (U = 6.000, Z = −6.606, p ≤ 0.001). Thus, patients who required TKA had a significantly lower KSS score than patients who required other treatments.

Conclusion

According to the data obtained in the studied group of patients, the characteristics of the patient at high risk of requiring TKA are the following: a female patient over 65 years of age who associates hypertension, high ESR, and fibrinogen values ​​with KSS score and KSS function with low values, recording an average value of 56.70.