Correlation between groin pain and cup design of hip-resurfacing implants: a prospective study

Purpose

Cup design has been incriminated as the source of groin pain after hip resurfacing but has not been well described; thus, it was assessed in a prospective study looking at three implant types.

Methods

A group-match was done between three groups of hip resurfacing devices according to age, sex, body mass index, activity level, osteoarthritis aetiology and pre-operative scores.

Results

The global groin pain rate was 5.7 % at six months and 2.7 % at last follow-up. Groin pain rate was significantly different between the three groups (p = 0.004) and had a strong influence on the subjective results (p = 0.04). No groin pain emerged between six months and last follow-up. No clinical differences were noted in Harris hip score and Merle d’Aubigné-Postel score at last follow-up. However, the Oxford hip score and Devane activity score were significantly lower for cups with macrostructures.

Conclusion

The low groin pain rate in this prospective cohort was probably secondary to the specific surgical technique used and seems to be correlated with cup design. Macrostructures on the external part of the cup could be significantly harmful.