TOTAL SHOULDER PROSTHESIS VERSUS SIMPLE HUMERAL PROSTHESIS FOR PRIMARY CENTERED OSTEOARTHRITIC DEGENERATION

Abstract

Purpose of the study: The purpose of this study was to compare mid-term results after total shoulder arthroplasty (TSA) versus simple humeral arthroplasty (SHA) for the treatment of primary centered osteoarthritic degeneration of the shoulder joint.

Material and methods: The series included 41 Aequalis prostheses (27 TSA, 14 SHA) implanted by the same surgeon. TSA was performed in 21 women and six men, mean age 68.3 years (range 51–78). SHA was performed in nine women and five men, mean age 68.3 years (range 58–83). The glenoid cavity presented concentric wear (type A) in 70% and asymmetric wear (type B) in 30% of patients undergoing TSA. Type A wear was observed in 57% of the patients undergoing SHA and type B (or C) wear in 43% of them. Mean follow-up was 35 months (range 24–49) for TSA and 37 months (24–59) for SHA. The Constant score and the Neer classification were noted. The position of the implants and lucent lines was noted on plain x-rays.

Results: For the TSA patients, the mean non-weighted Constant score was 82/100 points (gain of 48 points), anterior elevation was 151° (gain 54°), and active external rotation 44° (gain 29°). For the SHA patients, the mean non-weighted Constant score was 71/100 points (gain 41 points), active anterior elevation 135° (ain 46°), and active external rotation 43° (gain 28°). The Neer classification demonstrated excellent or satisfactory outcome for 93% of the TSA patients and 86% of the SHA patients. TSA was more effective than SHA for pain relief (p=0.045). Periglenoid lucent lines were observed for 63% of the TSA but with no loosening or complication for the glenoid component at last follow-up.

Discussion: Compared with a simple humeral prosthesis, total shoulder arthroplasty was more effective for the treatment of primary centered osteoarthritis of the shoulder joint.