RADIOLOGICAL ANALYSIS OF DELTA III REVERSE SHOULDER ARTHROPLASTY FOR ACUTE COMPLEX PROXIMAL HUMERAL FRACTURES IN ELDERLY POPULATION WITH A FOLLOW-UP FROM 1 TO14 YEARS

Abstract

Synthesis and hemi-prosthesis give well known radiological results for acute proximal complex humeral fractures in elderly population. We wanted to expose the radiological outcome of the reverse concept in this indication.

From 1993 to 2007, forty one DELTA III were implanted for thirty two three-part and four-part displacements and nine fracture-dislocations, in 3 males for 38 females, with an average age of seventy five years. The results were estimated with AP and LAMY profile X-rays.

Because of nine deceases and two moving, thirty cases were reviewed with a mean follow-up of 6.5 years, range 1 to 14. The radiographs showed: two 2-mm thick borders on the glenoid at four and eight years with a scapular notch at 11 years and an aseptic loosening of the base plate at 12 years with a broken polar inferior screw. The patient underwent an easy surgical revision because of a fair bone stock. There was no wear of the polyethylene. According to the NEROT classification, seventeen inferior scapular notches were observed with a mean occurrence time of 4.7 years. The seven type-1 notches appeared at a mean of 2 years and the five type-2 notches at a mean of 4.3 years. We observed three type-3 notches which reached the inferior screw at 5,6 and 7 years, and two type-4 notches which extended beyond the inferior screw at 6 and 7 years follow-up, respectively. There seem to be two distinct patters of notches: mechanical, stable proximal humeral bone loss because of an impingement between the humeral component and the inferior scapular pillar and biological, progressive in size, evolving over time with proximal humeral bone loss because of polyethylene disease; the longer the follow-up, the more severe the notch. Fourteen inferior spurs, stable after emergence, were reported with a mean occurrence time of 2.5 years range 1 to 6 years. One joint ossification occurred at 6 months and was stable at 6 year follow-up. The humeral results consisted in four medial (5,6,7 and 10 years) proximal bone looses and two bone-cement interface medial borders on the two thirds of the height of the stem at 5 year follow-up. In these six cases, there was a notch associated. We reported one case of septic humeral loosening at 2 year follow-up.

For acute proximal humeral complex fractures in elderly population, when re-fixation of the tubercles on the classical orthopaedics devices is impossible, the use of a DELTA III prosthesis shows, with a mean follow-up of 6.5 years, worrying images in 70% of the cases. These images are on the glenoid in 70% of the cases, appeared before seven years in 86% and are progressive in 50% of the cases. But, we have only one re-intervention for an aseptic loosening of the base plate at a twelve year evolution. New developments in design and bearing surfaces and a more long term results will probably provide more durable utilization of the reverse concept in this indication.