# The Effect of Hip Arthroplasty on Gait Function: Comparison of Ceramic‐On‐Ceramic Hip Resurfacing, Metal‐On‐Metal Hip Resurfacing, and Total Hip Arthroplasty

## TL;DR

This study compares how different hip replacement surgeries affect walking ability, finding that ceramic-on-ceramic hip resurfacing performs similarly to metal-on-metal versions but avoids metal ion issues.

## Contribution

Ceramic-on-ceramic hip resurfacing is shown to be a viable alternative to metal-on-metal hip resurfacing without compromising gait function.

## Key findings

- Ceramic-on-ceramic and metal-on-metal hip resurfacing showed similar postoperative gait improvements compared to a healthy control group.
- Total hip arthroplasty showed asymmetric ground reaction forces and weaker push-off compared to resurfacing groups.
- Ceramic-on-ceramic hip resurfacing effectively addresses metal ion concerns while maintaining functional benefits.

## Abstract

Ceramic‐on‐ceramic hip resurfacing arthroplasty (CoC‐HRA) has been developed to eliminate metal ion concerns which have been associated with metal‐on‐metal hip resurfacing arthroplasty (MoM‐HRA) while maintaining similar functionality. The aim of the study was to examine gait function pre‐ and postoperatively between CoC‐HRA, MoM‐HRA, and THA using subjective and objective measures with comparison to a healthy control group. Nineteen unilateral CoC‐HRA, 19 unilateral MoM‐HRA, and 18 unilateral THA gender, age, and BMI matched participants completed patient‐reported outcome measures (PROMs) (Oxford hip score [OHS] and metabolic equivalence of task score [MET]) and underwent gait analysis on an instrumented treadmill, preoperatively (2–8 weeks) and then postoperatively (40–52 weeks). Spatiotemporal measures and vertical ground reaction forces (GRF) were recorded. Statistical parametric mapping was used to detect differences in GRF between affected and nonaffected leg and to healthy controls. Preoperatively, there were no differences between groups in PROMs or objective measures. All groups showed an improved OHS postoperatively with only CoC‐HRA and MoM‐HRA demonstrating significant increase in MET. Postoperatively, TWS in both HRA groups improved with no difference to CON while THA was unable to demonstrate improvements. Postoperatively, at 6.5 km/h, THA demonstrated an asymmetric GRF profile, whereas CoC‐HRA and MoM‐HRA showed no differences between legs. In comparison of the affected leg GRF, THA demonstrated a weaker push off when compared to both resurfacing groups and CON. CoC‐HRA and MoM‐HRA showed no significant differences to CON. CoC‐HRA emerges as a potential alternative to MoM‐HRA, effectively addressing metal ion release concerns while retaining similar functional benefits.