Is a generic targeting guide useful for glenoid component placement in shoulder arthroplasty?

This study compared postoperative glenoid component version using traditional instrumentation to a generic glenoid targeting guide during total or reverse total shoulder arthroplasty.

Glenoid component version was measured on postoperative radiographs of 184 shoulders (traditional, 109; targeting guide, 75). Demographics, preoperative imaging, and operative technique were identified from medical records. Absolute deviation from neutral version and standard deviations (SDs) were calculated.

Average mean ± SD deviation in component version for the traditional technique group was 10° ± 7° compared with 9° ± 6° for the targeting guide group (P = .37; SD P = .12). No significant difference was noted based on operation, body mass index, preoperative version, or operative indication. For the last 30 shoulders in the targeting group, the absolute mean deviation was 6° compared with 11° in the first 30 of that group (P < .01) and 10° in the entire traditional group (P = .01). The SD in the last 30 shoulders in the targeting group was 5° compared with 7° in the first 30 in that group (P = .04) and 7° in the traditional group (P < .01).

No significant difference in component accuracy was noted between the 2 techniques. The narrower SD in the targeting group, although not statistically significant, suggests less glenoid placement in the extremes of version. A learning curve was noted with the targeting guide, with significantly improved accuracy in later patients.