Hip resurfacing arthroplasty in women: A novel ceramic device enables near normal gait function

Background: Gait function improves after Total Hip Arthroplasty (THA) but is not restored to normal levels. Metal-on-metal Resurfacing Arthroplasty (MoM-HRA) is an alternative to THA and has shown to restore normal levels gait function and physical activity but has been restricted to men owing to problems of metal-ion release. Ceramic HRA (cHRA) removes the cobalt-chrome bearing surfaces, thereby eliminating these specific metal-ion concerns and aiming to be safe for females. Research question: Is there a difference in gait function of female cHRA patients compared to female THA using subjective and objective measures? Methods: Fifteen unilateral cHRA and 15 unilateral THA, age and BMI matched, completed patient reported outcome measures (PROMs) (Oxford Hip Score, EQ5d and MET score) and underwent gait analysis using an instrumented treadmill pre- (2-10 weeks) and post-operatively (52-74 weeks). Maximum walking speed (MWS), Vertical GRF of the stance phase, GRF symmetry index (SI) and spatiotemporal gait measures were recorded. Patients were compared to age, gender and BMI healthy controls (CON). Results: There were no differences in PROMs or gait function between groups pre-operatively. Post- operatively, cHRA had a higher MET score (11.2 vs 7.1, p = 0.02) and a higher MWS (6.2 vs 6.8 km/hr, p = 0.003) compared to THA. cHRA had a similar GRF profile to CON, whereas THA had a reduced push-off force at 70-77 % of the stance phase compared to CON. At faster walking speeds of 6 km/hr walking speed, THA displayed an asymmetric GRF profile (SI<4.4 %) whereas the cHRA patients continued to display a symmetrical gait profile. cHRA was able to increase step length from pre-op levels (63 vs 66 cm, p = 0.02) and produced a larger step length compared to THA (73 vs 79 cm, p = 0.02). Significance: Female cHRA returned to levels of gait function and activity similar to healthy controls unlike female THA.

Automated summary

The study aimed to compare gait function in female patients undergoing ceramic hip resurfacing arthroplasty (cHRA) and total hip arthroplasty (THA). The results showed that compared to THA, cHRA patients had higher MET scores and maximum walking speed, as well as more symmetrical gait and longer step length. The study suggests that cHRA allows female patients to regain gait function and activity levels similar to healthy individuals.