Elsevier

Journal of Shoulder and Elbow Surgery

Volume 17, Issue 6, November–December 2008, Pages 914-920
Journal of Shoulder and Elbow Surgery

Original Article
Comparison of conforming and nonconforming retrieved glenoid components

https://doi.org/10.1016/j.jse.2008.04.010Get rights and content

The purpose of this study was to compare differences in wear performance of conforming and nonconforming glenoid designs, using clinical, radiographic, and retrieved polyethylene glenoid component outcome Sixty-three glenoids met the study criteria, and each glenoid was assigned to the conforming group (if the radii of curvature of the humeral and glenoid components were identical) or the nonconforming group (if a mismatch existed between the radii of curvature). The mean length of implantation was 5.6 ± 5.5 years in the conforming group and 3.1 ± 3.1 years for the nonconforming group (P < .05). The loosening score was 3.2 ± 2.0 in the conforming group and 2.4 ± 1.2 in the nonconforming one (P < .05). The nonconforming group had a significantly greater burnishing score (P < .01), while the conforming group had greater abrasion and delamination scores (P < .05). Articular conformity contributes to differences observed from retrieved polyethylene glenoid components, which are consistent with differences in performance that may influence loosening.

Section snippets

Materials and methods

From 1979 to 2006, total shoulder arthroplasty components were retrieved during revision surgery at a single hospital. The components were assigned an anonymous number and stored in the laboratory until analysis. Seventy-eight retrieved glenoid components from 73 patients were available from 4 identifiable manufacturers (52: Biomet, Warsaw, IN; 17: Neer II [Smith & Nephew, Inc. - Orthopedics, Memphis State, TN]; 6: Custom HSS [Hospital for Special Surgery, New York, NY]; and 2: Depuy

Results

Of the 63 glenoids that met the study criteria, clinical information was available for 56 (from 54 patients). For the conforming group, 27 glenoids were examined for wear damage, with clinical information available on 24. For the nononforming group, 36 were examined for damage, with clinical information available on 32.

The mean patient age was similar between the 2 groups, but the length of implantation was significantly greater in the conforming group at 5.6 ± 5.5 years, compared to only 3.1 ±

Discussion

The glenohumeral joint is an enarthrodial articulation with a hemispherical humeral head and a shallow glenoid that allows multiplanar range of motion but relies on the surrounding soft tissues to provide stability. The goal of total shoulder arthroplasty is to replicate natural motion and stability, while limiting wear and maintaining fixation of the prosthesis to the host bone.21 In the native shoulder, the humeral head may translate 1.5 mm from anterior to posterior and 1.1 mm superior to

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