Early migration of a partially cemented fluted glenoid component inserted using a cannulated preparation system

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiology

Background:

• Total shoulder arthroplasty (TSA) is a common procedure for severe shoulder osteoarthritis.
• Accurate measurement of glenoid component micromotion is crucial for assessing implant stability and longevity.
• Radiostereometric analysis (RSA) offers high precision in detecting early component migration.

Purpose of the Study:

• To evaluate early glenoid component migration using RSA in patients undergoing TSA.
• To correlate migration patterns with radiographic findings and clinical outcomes at two years post-operatively.
• To investigate the relationship between initial component stability and osseointegration.

Main Methods:

• RSA was employed to track the migration of 11 partially cemented fluted pegged glenoid components.
• Patients with osteoarthritis underwent TSA with an improved surgical technique.
• Clinical assessments (ASES, Constant-Murley scores) and CT scans were performed at two years.

Main Results:

• Two migration patterns were observed: minimal migration and significant rotation (>6°) within three months.
• CT scans at two years revealed osseointegration in the minimal migration group and cystic changes/osteolysis in the early migration group.
• Despite differing migration and osseointegration patterns, both groups showed similar clinical results.

Conclusions:

• Rapid early migration, focal lucency, and lack of osseointegration occurred in three of 11 components.
• This suggests that insufficient initial stability leads to early micromotion and impedes osseointegration.
• Early RSA assessment can identify components at risk for failure in TSA.