Enhancement Of Glenoid Prosthesis Anchorage Using Burying Technique

Seventy unconstrained total shoulder prostheses were evaluated with a mean follow-up of 42 months (range, 24-96 months). A flat polyethylene cemented glenoid device with 2 fixation points was always used. It was a slightly undersized device to facilitate insertion. Glenoid modifications were assessed on anteroposterior (AP) views (3 rotations) and with a modified axillary lateral view using Bernageau technique. We noted the thickness of the radiolucent lines, whether they were complete or incomplete, and how they had evolved over 12 months. On coronal x-rays, only 7 devices had no radiolucent line at 12 months, 42 had a partial radiolucent line, and 20 a complete radiolucent line, including 2 with a radiolucent line greater than 2 mm that seemed to be loose. One device had migrated secondary to an anterior dislocation. Radiolucent lines were clear in 90% of cases and had evolved in 27% of cases. Radiographically, the loosening rate was 28%. Comparison of the clear radiographic radiolucent lines, clinical parameters (constant score), and the position of the implants did not demonstrate any predictive factor for evolution of the periglenoid radiolucent lines. Age-and sex-weighted constant score at 42 months was 87.7 %. The technique was developed to spare the glenoid bone, which is often deteriorated by the degenerative process, and to obtain stable primary fixation on the subchondral bone. The clear radiolucent lines noted immediately postoperatively led us to improve our technique by making small perforations in the subchondral bone and by performing cementing in 2 stages. Although no revision surgery was performed, the bone preservation observed suggests that this would be possible in good conditions.