Novel molded antibiotic cement spacer: is it better than handmade cement spacer for treatment of chronically infected total hip arthroplasty?

PURPOSE: A handmade antibiotic cement spacer is the easiest method for producing a spacer for treating chronic periprosthetic joint infection after total hip arthroplasty (THA). However, a molded spacer offers more head and stem sizes to match the patient's anatomy. The purpose of this study was to evaluate the functional outcomes and complications between handmade and molded spacers.

METHODS

This retrospective case note study compared the functional results, re-infection rate, and spacer related complications after the first stage and second stage exchange arthroplasty between a handmade spacer and a novel molded cement spacer with three sizes of femoral head (45, 50, and 55 mm) and two stem sizes (small, large).

RESULTS

Fifteen chronically infected THA patients were identified: nine handmade and 6 molded spacers. The modified Harris Hip Score showed no inter-group differences pre-operatively and after first stage and second stage exchange arthroplasty. The erythrocyte sedimentary rates and C-reactive protein concentrations were similar at all time points, and there were no re-infections. The molded spacer group showed lower post-operative complications with no spacer fractures, spacer dislocations, and periprosthetic fractures, but two had spacer subsidence. The handmade spacer had two spacer fractures, one spacer dislocation with a periprosthetic femoral fracture, and four cases of spacer subsidence.

CONCLUSION

Our small study showed no differences in functional outcomes and no re-infections in either group, but higher spacer-related complications occurred in the handmade spacer group. These data suggest molded spacers are better than handmade spacers.