Mid-term survivorship analysis of a shoulder replacement with a keeled glenoid and a modern cementing technique

Abstract

We have investigated the mid-term outcome of total shoulder replacement using a keeled cemented glenoid component and a modern cementing technique with regard to the causes of failure and loosening of the components. Between 1997 and 2003 we performed 96 total shoulder replacements on 88 patients, 24 men and 64 women with a mean age of 69.7 years (31 to 82). The minimum follow-up was five years and at the time of review 87 shoulders (77 patients) were examined at a mean follow-up of 89.1 months (60 to 127). Cumulative survival curves were generated with re-operations (accomplished and planned), survivorship of the proshesis, loosening of the glenoid (defined as tilt > 5 degrees or subsidence > 5 mm), the presence of radiolucent lines and a Constant score of < 30 as the endpoints. There were two re-operations not involving revision of the implants and the survival rate of the prosthesis was 100.0% for the follow-up period, with an absolute Constant score of > 30 as the endpoint the survival rate was 98%. Radiological glenoid loosening was 9% after five years, and 33% after nine years. There was an incidence of 8% of radiolucent lines in more than three of six zones in the immediate post-operative period, of 37.0% after the first year which increased to 87.0% after nine years. There was no correlation between the score of Boileau and the total Constant score at the latest follow-up, but there was correlation between glenoid loosening and pain (p = 0.001). We found that total shoulder replacement had an excellent mid-term survivorship and clinical outcome. The surgical and cementing techniques were related to the decrease in radiolucent lines around the glenoid compared with earlier studies. One concern, however, was the fact that radiolucent lines increased over time and there was a rate of glenoid loosening of 9% after five years and 33% after nine years. This suggests that the design of the glenoid component, and the implantation and cementing techniques may need further improvement.

CORR Insights®: No Differences in Early Results of a Hybrid Glenoid Compared With a Pegged Implant

“…There is a concern that the results of the current study could be different in a few years due to the relatively short followup, as well as the potential for the loosening rate to increase over time [3]. Having experienced early failures of ''promising new'' metal-backed glenoid designs, it is important to follow patient cohorts that received hybrid glenoid carefully, and to report encouraging results (or stop further application of the product if catastrophic failures are found).…”

“…A ''side effect'' of the procedure's efficacy, however, is an ever-increasing number of procedures [2,4], which inevitably result in more revisions. Many of these revisions are caused by painful glenoid loosening, an incident which can increase over time [3]. Avoiding this complication poses high demands on the design of the glenoid component, as well as the implantation technique [1,5].…”

The glenoid in total shoulder arthroplasty

“…"Modern" technique has been shown to improve radiographic results but the exact definition of modern technique remains somewhat unclear. A number of authors including Norris, Mileti and Kasten have all written on the "modern" technique for fixation though there is considerable variation in what that means [49][50][51]. Common elements to modern technique include lavage and drying of the vault and cement pressurization into the glenoid with a syringe [52].…”

Fixation of the glenoid component in total shoulder arthroplasty: What is “modern cementing technique?”

“…25,26 His initial positive experiences with TSA for the management of glenohumeral osteoarthritis have been confirmed by numerous clinical studies reporting significant improvements in pain and function. 8,[15][16][17]19,34 Despite the highly satisfactory clinical outcomes and low reported complication rates, glenoid loosening and revision for glenoid loosening remain the major issues concerning the longevity of TSA. The reported incidence of radiolucency at the boneecement interface is high, up to 30% to 90%, 4,7,27,34 the rate of radiologic loosening is between 0% and 44%, 29,40 and rates of glenoid revision for loosening are 8% to 10%.…”

“…Specifically, techniques for cementing the glenoid have evolved and ''modern cementing techniques'' have been reported to result in improved radiologic and clinical outcomes of TSA. 17,23,27 The methods used by each of these authors were different, however, which raises the question: What actually constitutes a modern cementing technique?…”