2017 ISAKOS Biennial Congress ePoster #1248

 

Association Between Kneeling Ability and Contact Pressure of Anterior Aspect of the Knee

Kunihiko Watamori, MD, Toon, Ehime JAPAN
Hiromasa Miura, MD, PhD, Prof., Toon, Ehime JAPAN
Kazunori Hino, MD, PhD, Toon, Ehime JAPAN
Tatsuhiko Kutsuna, MD, PhD, Toon, Ehime JAPAN
Hiroshi Kiyomatsu, MD, PhD, Toon-City, Ehime JAPAN
Yasumitsu Ishimaru, Toon City, Ehime JAPAN
Seiji Watanabe, MD, Toon, Ehime JAPAN

Ehime University Graduate School of Medicine , toon, JAPAN

FDA Status Not Applicable

Summary

We hypothesized that contact pressure of anterior aspect of the knee might be a contributor to kneeling pain after total knee arthroplasty. We measured the contact pressure using I-SCAN. The peak of contact pressure with kneeling on hard floor was 0.82 N/cm²·kg. Thirty percent of patients could not kneel on hard floor. By reducing the contact pressure, all patients could kneel.

Abstract

Introduction

Kneeling is an important function for many daily activities, and the inability to kneel after total knee arthroplasty (TKA) is a frequent cause of dissatisfaction.
Patients often state that they can not kneel after TKA because of pain.
We hypothesized that contact pressure of anterior aspect of the knee might be a contributor to pain during kneeling.
The purpose of this study is to quantify the contact pressure of anterior aspect of the knee with kneeling after TKA and to confirm whether the kneeling pain associates with contact pressure.

Materials And Methods

Forty patients after TKA were asked to kneel down on I-SCAN (NITTA).
Each participant was asked to face forward and kneeling at 90° flexion (upright kneeling) without using hand support. We measured the contact pressure kneeling on hard floor directly and with the pad under the knee.
A kneeling score was obtained by analysis of the relevant section of the Oxford Knee Score. We used the Numerical Rating Scale (NRS) for evaluation of kneeling pain.

Results

The peak of contact pressure with kneeling on hard floor was 0.82 N/cm²·kg.
Using the pad, the peak of contact pressure was 0.14 N/cm²·kg. A kneeling score and NRS were significantly improved.

Discussion

Patients with osteoarthritis have a poor ability to kneel preoperatively. Although this improves following TKA, patients are still expected to have some difficulty kneeling.
In this study, twelve patients (30%) could not kneel on hard floor. Using the pad, the average of NRS was decreased by 30%, and all patients could kneel.
These results suggest that pain is likely to be a limiting factor in the ability to kneel in post-TKA patients. By reducing the contact pressure, it is possible to reduce pain and increase the patient satisfaction for postoperative kneeling.