# Early Outcome of Simultaneous Bilateral Total Knee Arthroplasty Through the Oxford Knee Score in a Developing Country: A Prospective Cohort

## TL;DR

This study evaluates the outcomes of simultaneous bilateral knee replacement surgery in Pakistan using the Oxford Knee Score at six weeks and six months post-surgery.

## Contribution

The study identifies six months post-surgery as the optimal time to assess outcomes using the Oxford Knee Score for this procedure in a developing country.

## Key findings

- The mean Oxford Knee Score improved significantly from 20.6 at six weeks to 42.7 at six months post-surgery.
- The improvement in scores was clinically significant between six weeks and six months (p-value=0.03).
- Most patients (77.6%) had severe osteoarthritis (Grade IV Kellgren Lawrence Grading).

## Abstract

Introduction

The most common degenerative joint disease in adults is osteoarthritis. The gold standard treatment option for this aging society with greater functional demands is total knee arthroplasty. The Oxford Knee Score (OKS) assesses factors such as stiffness, pain, function, satisfaction, and quality of life, allowing you to quantify treatment success after surgery. According to published research, there isn't a perfect postoperative timepoint to use the OKS to obtain TKA outcomes. Therefore, at the time of evaluation, the OKS should reflect the best possible outcome for the patient group. This study was conducted to see the OKS in patients who underwent simultaneous bilateral knee replacement at six weeks and six months postoperatively and to see if there was a clinically significant difference in the mean OKS.

Methods

This prospective cross-sectional study was conducted at the Section of Orthopedic Surgery at Aga Khan University Hospital, a tertiary care center in Karachi, Pakistan. Patients who underwent simultaneous bilateral total knee replacement from October 2023 till December 2023 were included; exclusion criteria included patients who had a recent knee infection and extensor mechanism disruption. OKS was calculated at six weeks and six months postoperatively.

Results

The total number of patients included in the study was 49 with a mean age of 61.9 +/- 6.1. There were 42 (85.7%) females and 7 (14.3%) males. The mean BMI of our patients was 33.3 +/- 3.8. The radiographic Kellgren Lawrence Grading (KLG) was used and 38 (77.6%) patients were placed in Grade IV KLG, and 11 (22.4%) were placed in Grade III KLG. The mean OKS preoperatively was 12.6 +/- 3.5. At six weeks, the OKS showed improvement, with the mean being 20.6 +/- 3.0. At six months postoperatively, there was a significant improvement in the OKS, with the mean now being 42.7 +/- 2.4. At six weeks post-surgery, the mean improvement in the OKS score was 7.9 +/- 2.71, whereas at six months post-surgery, the mean improvement in the OKS score was 30.1 +/- 3.6. This difference was significant (p-value=0.03).

Conclusion

Our study showed a clinically significant difference between the mean OKS at the six-week and six-month timeline, with a significant increase in the mean improvement OKS score at six months. OKS should be utilized six months postoperatively to assess the outcome of simultaneous bilateral knee arthroplasty patients.