Delta III reverse shoulder arthroplasty: radiological outcome for acute complex fractures of the proximal humerus in elderly patients.

PURPOSE OF THE STUDY

Acute complex proximal humerus fractures in the elderly population, treated by internal fixation or hemiarthroplasty, give well reported radiological results. We investigated the radiological outcome of the reverse arthroplasty concept in this indication.

MATERIAL AND METHODS

From 1993 to 2007, 41 Delta III prostheses were implanted following 32 three-part and four-part displaced fractures, and in nine fracture/dislocations; three fractured patients were males and 38 females; mean age at fracture time was 75 years. The results were evaluated on AP and Lamy lateral shoulder views.

RESULTS

Since nine of these patients were deceased and two had moved, 30 cases were available at review, with a mean follow-up of 6.5 years (range, 1-14). The radiographs showed two thick radiolucent lines on the glenoid component with one aseptic loosening of the base plate at 12 years. Based on the Nérot classification, 17 cases of inferior scapular notching were, in total, observed. The mean time to onset was 2 years for the seven grade 1 notches (41%), 4 years for the five grade 2 notches (30%), 5 years for the three grade 3 notches (17%) and 6 years for the two grade 4 notches (12%). Fourteen inferior spurs (stable after emergence) were reported with a mean time to onset of 2.5 years (range, 1-6 years). One joint ossification occurred at 6 months and was stable at the 6-year follow-up review. The humeral component results comprised four cases of medial (5, 6, 7 and 10 years) proximal bone loss and two cases of bone-cement interface deterioration (medial radiolucent lines at two-third of the stem height at the 5-year follow-up). In these six cases, a notch was present above this area. In addition, one case of humeral septic loosening is reported at 2-year follow-up.

CONCLUSION

For acute proximal humeral complex fractures in the elderly population, when refixation of the tuberosities on a classical orthopaedic devices appears compromised, the use of a Delta III reverse prosthesis is an attractive alternative; however, with a mean follow-up of 6.5 years, this prosthesis demonstrates unsatisfactory images in 70% of the cases. These flaws were noted on the glenoid component in 70% of the cases, appeared before 7 years in 86% and were progressive in 50% of the cases. However, only one revision was required for an aseptic loosening of the base plate at 12 years. New developments in designs and bearing surfaces and larger numbers analysis of long-term results will probably be needed to encourage extensive utilization of the reverse concept in this fracture indication.

LEVEL OF EVIDENCE

Level IV. Therapeutic retrospective study.