New design of a cementless glenoid component in unconstrained shoulder arthroplasty: a prospective medium-term analysis of 143 cases

Abstract

The uncemented glenoid implants in total anatomical shoulder arthroplasty are likely to be accused of problems like dissociations, secondary rotator cuff tear, and wear of polyethylene (PE). This work is a clinical and radiological prospective review of 143 cases of anatomical total shoulder arthroplasty using a new metal back uncemented glenoid implant (MB) in order to see if this new implant induces those complications. A total of 143 cases were operated between 2003 and 2011. In a first part, the whole series of 143 cases was radiologically studied in order to quantify the lateralisation induced by the MB implant. In a second study, 37 cases had a mean follow-up of 38 months (24–75, mean 32) and served for the clinical and radiological final study. Pre- and postoperative clinical evaluation was done using the Constant–Murley score and the simple shoulder test from Matsen. The final X-rays served to detect an eventual secondary narrowing of the joint space and to analyse the frequency of radio lucent lines (RLL) and loosenings. Despite a small radiological lateralisation in comparison with the normal contralateral side (0.36 cm, p = 0.02), the clinical results after 2 years were similar to the published cemented glenoid implants series but without any RLL, glenoid loosening or joint narrowing. Some dissociations occured in the beginning and definitely eliminated by a design modification of the PE tray. The discussion tried to show that, despite a still short follow-up, this series is encouraging to continue to use this new MB implant. Different applications of the concept of universality and conversion are discussed, this tray been also the support of a glenosphere in reverse arthroplasty.

Complications of Shoulder Arthroplasty

“…We found an overall decrease in the rate of instability (1% [35 of 3,360 shoulders 9,20,21, 32,40,41,43,52,55,62,68,71,72,74,[76][77][78]83,87,103,106,108,[112][113][114][115][116]118,119,[121][122][123][124] ] in the current study compared with 4.9% [124 of 2,540 shoulders] in the earlier study 1 ). Component malposition (nonanatomic humeral and glenoid retroversion) and rotator cuff deficiency may lead to adverse kinematics of the glenohumeral joint, subsequent instability, edge loading of the glenoid component, and premature loosening 1,133 .…”

“…1-A and 1-B)1,54,71,72,131,142 . Efficacy regarding these surgical techniques remains largely unproven.loosening made up a majority of these events (217 [82%] of 264 shoulders) .…”

“…Efficacy regarding these surgical techniques remains largely unproven.loosening made up a majority of these events (217 [82%] of 264 shoulders) . Glenoid implant failure comprised 37.7%(130) of 345 complications after TSA 9,20,21,32,40,41,43,52,55,62,68,71,72,74,[76][77][78]83,87,103,106,108,[112][113][114][115][116]118,119,[121][122][123][124] …”

Loosening and revision rates after total shoulder arthroplasty: a systematic review of cemented all-polyethylene glenoid and three modern designs of metal-backed glenoid

“…Because of this, they were expected to be the ideal component. However, the results of clinical studies using the conventional MBG design were disappointing [2,16,17,[44][45][46][47][48][49][50][51]. These failures were caused by several factors.…”

Zementfreier anatomischer Glenoidersatz

“…Durch die Lateralisation der Glenoidlinie werden die Vorspannung auf die Rotatorenmanschette und der Gesamtdruck auf die Pfanne ebenso erhöht. Diese mechanischen Überlegun-gen scheinen aber nach Katz et al [19] keinen Einfluss auf das klinische Ergebnis zu haben.…”