Constantinos Roussos

Physical Activity Before and After Primary Total Hip Arthroplasty: A Registry-Based Study

Detailed assessment of activity before and after total hip arthroplasty (THA) including a long‐term followup period is lacking. Our objectives were to evaluate patient activity levels prior to disease onset, prior to THA, and at 5 and 10 years after surgery, and to determine the predictors of high activity 5 years after surgery.

A comparative assessment of small-head metal-on-metal and ceramic-on-polyethylene total hip replacement

Large-head metal-on-metal (MoM) total hip replacements (THR) have given rise to concern. Comparative studies of small-head MoM THRs over a longer follow-up period are lacking. Our objective was to compare the incidence of complications such as infection, dislocation, revision, adverse local tissue reactions, mortality and radiological and clinical outcomes in small-head (28 mm) MoM and ceramic-on-polyethylene (CoP) THRs up to 12 years post-operatively. A prospective cohort study included 3341 THRs in 2714 patients. The mean age was 69.1 years (range 24 to 98) and 1848 (55.3%) were performed in women, with a mean follow-up of 115 months (18 to 201). There were 883 MoM and 2458 CoP bearings. Crude incidence rates (cases/1000 person-years) were: infection 1.3 vs 0.8; dislocation 3.3 vs 3.1 and all-cause revision 4.3 vs 2.2, respectively. There was a significantly higher revision rate after ten years (adjusted hazard ratio 9.4; 95% CI 2.6 to 33.6) in the MoM group, and ten of 26 patients presented with an adverse local tissue reaction at revision. No differences in mortality, osteolysis or clinical outcome were seen. In conclusion, we found similar results for small-head MoM and CoP bearings up to ten years post-operatively, but after ten years MoM THRs had a higher risk of all-cause revision. Furthermore, the presence of an adverse response to metal debris seen in the small-head MOM group at revision is a cause for concern.

Statins may reduce femoral osteolysis in patients with total hip arthroplasty

In experimental studies, statin use has been associated with reduction of osteoclastic activity and promotion of bone formation around implants. Moreover, a large clinical study recently reported a substantially reduced risk of revision for aseptic loosening among statin users with THA. Our objective was to evaluate the influence of statin use on the development of femoral osteolysis within 5 years after THA. We conducted a case‐cohort study including all THAs presenting with femoral osteolysis at the 5 year visit (cases) and compared them with those without osteolysis (controls). Cases and controls were identified from a cohort of primary THAs operated between 2001 and 2005. Seven hundred thirty‐five THAs were included, mean age 68 years. Five years after surgery osteolysis had developed around the femoral component of 40 THAs (5.4%). Ever‐use of statins was much less frequent among cases (5 of 40, 12.5%) than among controls (199 of 695, 28.6%). The crude risk ratio of femoral osteolysis among statin users was 0.36 (95% CI 0.14; 0.92). After adjusting for age, sex, activity level, BMI, diagnosis, bearing surface, and type of stem, the adjusted risk ratio was 0.38 (95% CI 0.15; 0.99). In conclusion, statin use was associated with a reduced risk of developing femoral osteolysis 5 years after THA. Statins may be useful for reducing the risk of implant failure following THA.

TOTAL HIP ARTHROPLASTY WITH A LARGE DIAMETER METAL-ON METAL CUP (DUROM) AND A STANDARD STEM: SHORT-TERM RESULTS

Introduction: Large-diameter metal-on-metal (LDMOM) cups have been used in total hip arthroplasty (THA) advocating superior results with respect to dislocation rates, range of motion, and long-term survival. The Durom cup used as part of the Durom hip resurfacing system has been incriminated with poor short-term results sometimes correlated to incorrect positioning of either the femoral or acetabular component due to poor exposure during this procedure. Our objective was to evaluate short-term results of the Durom cup used in conjunction with standard stems.