Long-term follow-up results of a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels

Radiographic changes and clinical outcomes associated with an adjustable diaphyseal press-fit humeral stem in primary reverse shoulder arthroplasty

BACKGROUND

Press-fit humeral fixation in reverse shoulder arthroplasty (RSA) has become increasingly popular; however, radiographic analysis of these stems is limited. We aimed to evaluate the radiographic and clinical outcomes of an adjustable diaphyseal press-fit humeral stem in primary RSA.

METHODS

We conducted a retrospective review of 232 primary RSAs in 219 patients performed by a single surgeon using this system. Radiographic outcomes were evaluated in patients with at least 2 years of radiographic follow-up. Standardized postoperative digital radiographs were analyzed for loosening, osteolysis, and stress shielding. Clinical outcomes in patients who also had complete clinical data sets were evaluated at the most recent follow-up.

RESULTS

Radiographic evidence of loosening was identified in 1 RSA (0.4%) associated with deep infection. Aseptic loosening was not observed. No stems were identified as being at high risk for loosening. Internal stress shielding was observed proximal to the coated diaphyseal component in 226 shoulders (97.4%). This finding was often visible at 3 months (92.7%) and predictably progressed on subsequent radiographs. Progression beyond the 2-year period was rarely seen (4.4%). No external stress shielding or osteolysis was observed. Thirty-six complications occurred in 33 patients (15.1%). At an average follow-up of 36.6 months, significant improvements were identified in all measured clinical outcomes (P < .001).

CONCLUSION

Predictable fixation is achieved using an adjustable diaphyseal press-fit humeral system in primary RSA. Internal stress shielding is commonly observed but does not appear to compromise quality of fixation or clinical outcomes.

Radiographic evaluation of short-stem press-fit total shoulder arthroplasty: short-term follow-up

BACKGROUND

Humeral loosening is an uncommon etiology for revision shoulder arthroplasty. We aimed to evaluate the radiographic and clinical outcomes of a short-stem press-fit humeral component after primary total shoulder arthroplasty.

METHODS

We reviewed our patient database, from January 2008 to December 2011, for primary total shoulder arthroplasties performed with a short-stem press-fit humeral component. Radiographs and clinical outcomes were evaluated in the immediate postoperative period and at the most recent follow-up, with at least 24 months of data for all patients.

RESULTS

There were 73 shoulders that met our inclusion criteria, but 4 underwent revision before 2 years' follow-up. Only 1 of these 4 was revised for aseptic humeral loosening. Sixty-nine shoulders had at least 24 months of radiographic follow-up, and 62 had radiographic and clinical follow-up. Of the 69 shoulders, 5 underwent revision for humeral loosening: 1 for aseptic loosening and 4 for infection. Two other shoulders with humeral loosening were asymptomatic, and the patients refused revision surgery. The overall revision rate for humeral loosening was 8.2% (6 of 73 shoulders). Radiolucent zones of any size were seen in 71.0%, with 8.7% of these shoulders identified as having humeral stems at risk of future loosening. Significant improvements were made in most of the measured clinical outcomes.

CONCLUSIONS

A high percentage of radiolucency was seen around the short-stem press-fit humeral components evaluated in this study at short-term follow-up. The overall rates of loosening and revision for the humeral implant examined in this study are higher than those noted in other recent studies evaluating press-fit stems. The cause of radiolucency and humeral loosening for this implant is not fully understood.