Abstract
Introduction
Metal on metal hip resurfacing arthroplasty (MoM HR) has the highest revision rates according to the UK National Joint Registry. Revisions for lesions associated with soft tissue necrosis (pseudotumors) have been associated with poor outcomes. There is a relative paucity of information on early revision of painful HR prostheses. We present the results of a series of patients who underwent early revision of painful MoM HR procedures.
Methods
This prospective study involved a consecutive series of patients undergoing revision of HR to THA. The diagnoses leading to revision are discussed. Clinical and radiological assessments were performed pre operatively as well as 6 weeks, 12 months postoperatively and yearly thereafter. Pre and post operative Harris Hip Score, Oxford Hip Score and WOMAC scores were calculated. Patient satisfaction was assessed using a visual analogue scale.
Results
Revisions were performed for recurrent pain and effusion, infection and proximal femoral fractures. Both components were revised in 20 cases.
There were 12 male and 13 female patients with average time to revision of 34.4 and 26.4 months respectively. The mean follow up period was 12.7 months (3 to 31). All patients reported relief of pain and excellent satisfaction scores (9/10 compared to 2/10 pre-operatively). Two patients experienced stiffness up to three months post operatively.
Pre operative Oxford, Harris and WOMAC hip scores were 39.1, 36.4 and 52.2 respectively. Mean post operative scores at last follow up were 17.4, 89.8 and 6.1 respectively (p< 0.0001 for each score). All patients except those with femoral neck fractures had at least a small effusion
Conclusion
These results show that conversion of painful hip resurfacing prostheses to total hip arthroplasty is associated with improved function, pain relief and high levels of patient satisfaction.
