William N. Levine
A canal-sparing total shoulder arthroplasty system that uses multiplanar osteotomy may restore proximal humeral anatomy with improved accuracy and precision compared to a stemmed arthroplasty system, according to published results.
William N. Levine, MD, and colleagues measured the difference between the anatomic center of rotation of the humeral head and the postoperative prosthetic center of rotation for 110 shoulder arthroplasties. Researchers included 55 cases with a stemmed arthroplasty system (Arthrex Univers II, Arthrex) and 55 cases with the new canal-sparing implant system that used a multiplanar osteotomy during humeral head preparation (Catalyst CSR Total Shoulder System, Catalyst OrthoScience). Researchers deemed cases clinically significant outliers if there was a change in center of rotation of 3 mm or more.
Results showed an average change in center of rotation of approximately 1.7 mm in the multiplanar osteotomy group vs. 2.8 mm in the stemmed group. Researchers found a lower incidence of clinically significant outliers in the multiplanar osteotomy group, with 14.5% of cases identified as outliers in the multiplanar osteotomy group compared with 40% of cases in the stemmed group. The multiplanar osteotomy group also consisted of more cases with a change of center of rotation of 1 mm or less (32.7% vs. 3.6%).
“This novel transformational prosthetic design borrowed from total knee concepts more anatomically replicates the proximal humeral anatomy by creating a series of chamfer cuts. The current study demonstrates that the center of rotation is more reproducibly and accurately replicated with the novel design compared to standard prostheses, where the humeral head is resected,” Levine told Healio.com/Orthopedics. “Clinical studies will need to be performed in the future to determine what, if any, clinical impact these findings will lead to.” – by Casey Tingle
Disclosures: The authors report no relevant financial disclosures.