Implantation of the humeral stem in primary TSAs by a press-fit manner may have better functional and radiographic outcomes when contrasted to cement fixation.
Total shoulder arthroplasty (TSA) is the definitive treatment for osteoarthritis of the glenohumeral joint. Fixation of the humeral stem involves either cementing
or press-fit. When compared to cemented stems, press-fit components have the potential to decrease operative time/costs and allow for easier revision, while still achieving a stable prosthetic fit. However, no clear consensus regarding long-term outcomes exists, thus the choice of fixation is variable among surgeons. The purpose of this study is to evaluate the differences in revision and complication rates, functional outcomes, and radiographic outcomes, between cemented and press-fit humeral stems in primary TSA.
A comprehensive search of the medical databases Medline, Embase, and Pubmed was conducted. Studies were included if patients underwent primary TSA for primary osteoarthritis or rheumatoid arthritis. Studies were excluded if humeral stem fixation technique was unclear or if multiple cementing techniques and/or surgical indications were performed in the cohort. Studies were screened independently by two reviewers and the quality was assessed using the MINORs criteria. Data extraction was performed in duplicate and included: humeral stem fixation, revision rate, complications not leading to revision, functional outcomes, and active range of motion (ROM).
Following text screening, a total of 36 studies were eligible for data extraction. Reported outcomes were between 12 to 60 months and included 300 patients with cemented stems and 1350 patients with press-fit stems (Table 1). Overall, cement fixation resulted in increased rate of complications not requiring revision (RR 3.0, 95% CI 1.6 to 5.7, P < 0.0001), decreased Constant scores (P <0.0001), as well as decreased active ROM (P < 0.0001). There was no significant difference in radiographic loosening of the humeral component (RR 1.7, 95% CI 0.1 to 31.3, P = 0.7193). Revision rates were comparable between groups at 12 to 60 months, (RR 1.2, 95% CI 0.5 to 3.2, P = 0.7218). Subgroup analysis demonstrated increased revision rates from 1.9% to 5.5% when reviewed at a mean of 89.4 months in patients undergoing cement fixation.
Discussion And Conclusion
At midterm follow-up, press fit fixation of the humeral stem in primary TSAs may result in improved outcomes compared to cement fixation. Press-fit fixation resulted in decreased complication risk, improved functional outcome scores and ROM, similar revision rates, and comparable radiographic humeral stem loosening rates. Furthermore, a significant increase in failure was observed with respect to cement fixation at long-term follow up (mean 89.4 months). Overall, with improved ease of revision and decreased operative time,
humeral press-fit fixation may be the optimal choice for TSAs. Further large randomized control trials are required to definitively confirm optimal fixation
technique, particularly with novel stem designs and stem length.