Radiological changes do not influence clinical mid-term outcome in stemless humeral head replacements with hollow screw fixation: a prospective radiological and clinical evaluation

Abstract

Background: Stemless shoulder arthroplasty is a fairly new concept. Clinical and radiological follow-up is essential to prove implant safety and concept. This prospective single-centre study was performed to evaluate the influence of radiological changes on clinical mid-term outcome following stemless humeral head replacement with hollow screw fixation.

Methods: Short- and mid-term radiological and clinical evaluations were performed in 73 consecutive shoulders treated mainly for idiopathic and posttraumatic osteoarthritis with stemless humeral head arthroplasty including 40 hemi- (HSA) and 33 total shoulder arthroplasties (TSA). Operating times of stemless implantations were compared to 110 stemmed anatomical shoulder prostheses. Appearances of humeral radiolucencies or radiological signs of osteolysis or stress shielding were assessed on standardized radiographs. Patients' clinical outcome was evaluated using the Constant score and patients' satisfaction was documented.

Results: Radiological changes, detected in 37.0%, did not affect clinical outcome. Constant scores significantly improved from baseline to short and mid-term follow-up (p < 0.001). The majority of patients (96.2%) were satisfied with the procedure. No loosening of the humeral head component was detected during a mean follow-up of 58 months. Operating times were significantly shorter with stemless compared to stemmed implants (p < 0.001).

Conclusions: Clinical mid-term outcome after stemless humeral head replacement was not affected by radiological changes.

Trial registration: The institutional review board (St. Vincent Hospital Vienna; 201212_EK01; date of issue: 11.12.2012) approved the study. The trial was registered at ClinicalTrials.gov ( NCT02754024 ). Retrospective registration.

Keywords: Anatomic shoulder arthroplasty; Hemiarthroplasty; Mid-term outcome; Radiological and clinical results; Stemless shoulder arthroplasty.

Conflict of interest statement

Ethics approval and consent to participate

The study was approved by the institutional review board of the St. Vincent Hospital Vienna, Austria (201212_EK01). The written informed consent was signed by all patients.

Consent for publication

Not applicable.

Competing interests

The first (PRH) and senior author (WA) are consultants for Arthrex, Inc. However, the authors have not received any financial payments or other benefits related to the subject of this article. The other authors do not have any conflict of interest.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1

The stemless humeral head Eclipse prosthesis consists of three components: the anatomical humeral head; the trunion for epiphyseal fixation; and the hollow cage screw for metaphyseal fixation. Published with permission from (Arthrex Inc., Naples, FL, USA)

Fig. 2

Anteroposterior radiographs of the stemless humeral head implant showing five radiographic zones including the superior and inferior interface (zone 1 and 5) and the interfaces around the hollow screw (zones 2, 3, and 4), which were used for the assessment of radiolucency and osteolysis

Fig. 3

Anteroposterior radiographs of a seventy-two-year-old woman made immediately after hemi shoulder arthroplasty (a), at the short-term follow-up showing no radiolucency or osteolysis (b), and at the mid-term follow-up showing osteophyte formation superior around the humeral head implant and inferior (c)

Fig. 4

Anteroposterior radiographs of a forty-year-old man made immediately after total shoulder arthroplasty (a), at the short-term showing partial osteolysis at the inferior trunion bone interface (b), and at the mid-term follow-up showing stable partial inferior osteolysis and minor superior radiolucency (c)

Fig. 5

Clinical outcome between hemi- (HSA; n = 27) and total shoulder arthroplasty (TSA; n = 26) at baseline (HSA: 38.8 ± 17.0% vs. TSA: 36.6 ± 13.9%, p = 0.594), at short (HSA: 74.0 ± 16.5% vs. TSA: 83.9 ± 14.4%, p = 0.024) and mid-term follow-up (HSA: 73.5 ± 17.3% vs. TSA: 84.2 ± 11.6%, p = 0.011)