Radiographic Changes and Clinical Outcomes Associated with Two Different Press-Fit Humeral Stems in Primary Reverse Shoulder Arthroplasty.

Abstract

Background: Reverse shoulder arthroplasty (RSA) is used commonly for a wide range of indications. The complications after the total shoulder replacements have been reported to be related with the prosthesis design. The type of the humeral stem is a consideration to reduce complication. Radiographic changes are seen at a high rate with new-generation press-fit stems.

Aim: This study aims to reduce proximal humeral bone loss after RSA could have been achieved with adjustable humeral stem when compared with monoblock stem.

Methods: A retrospective analysis was made of 52 patients treated with RSA using a press-fit humeral stem prosthesis. The patients were separated into two groups according to the type of humeral stem. The first group included 26 patients (18 females, 8 males) who underwent RSA using adjustable humeral stem. The second group included of 26 patients (17 females, 9 males) for whom monoblock humeral stem was used. Clinical and radiological evaluations were made based on the information obtained at 1, 3, 6, 12, and 18 months postoperatively. The follow-up duration was at least 18 months.

Results: There was no statistical difference between the adjustable and monoblock groups in respect to gender, age, height, and weight. According to the functional measurements at the final follow-up, no statistically significant difference was determined between the groups with respect to the Constant, UCLA, Oxford, DASH, and VAS values. In terms of radiographic changes, both groups were seen to have been similarly affected. It was found that, irrespective of the stem type used, the humeral side radiographic adaptation was found to be high, which negatively affected the functional results (P < 0.05).

Conclusion: The increased radiographic stress shielding adaptation leading to humeral osteolysis was found to have a negative effect on the functional results with the press-fit technique irrespective of stem design.