Cement and Press-fit Humeral Stem Fixation Provides Similar Results in Rheumatoid Patients

Abstract

It is unclear whether humeral stems should be fixed with or without cement. We question whether press-fit fixation would provide similar results to cemented stem fixation. We prospectively randomized 26 shoulders in 24 patients with rheumatoid arthritis (20 women, 4 men) to have either a cemented or press-fit stem. In the press-fit group, stems were matched to the medullary canal, while lavage, pressurizing and distal plugging were used in the cemented group. We followed patients with conventional radiographs and radiostereometric analysis (RSA) at 5 to 7 days, 4 months, 1 year, and 2 years after surgery. One patient died from unrelated causes before the 1-year followup, while the remaining patients were followed according to the protocol. All but two patients were very satisfied or satisfied at 2 years. No stem was radiographically loose. There was no difference in micromotion between groups. The average rotation for all axes was less than 0.25 degrees for both groups and the average translation was less than 0.32 mm for all three axes including subsidence, which was less than 0.1 mm for the uncemented stems. We concluded at 2 years these stems provided similar fixation in rheumatoid shoulders. Therapeutic Level I. See the Guidelines for Authors for a complete description of levels of evidence.