Resurfacing humeral prosthesis: do we really reconstruct the anatomy?

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Resurfacing shoulder arthroplasty aims to replicate natural anatomy and conserve bone stock.
• This study evaluates if this prosthesis restores normal glenohumeral relationships and clinical outcomes.

Purpose of the Study:

• To assess the anatomical restoration and clinical results of resurfacing shoulder arthroplasty.
• To investigate the correlation between the prosthesis and glenohumeral relationships.

Main Methods:

• A resurfacing shoulder implant was performed in 61 patients (64 shoulders) for various indications including osteoarthritis and avascular necrosis.
• Radiographic analysis was conducted preoperatively and postoperatively to assess anatomical changes.

Main Results:

• Average follow-up was 36 months, with Constant scores at 68 and Quick-Disabilities of Arm, Shoulder and Hand scores at 28.
• Radiographic analysis showed decreased humeral head diameter and height, increased medial and lateral humeral offset, and a tendency towards varus positioning.
• Glenoid depth increased postoperatively, with no significant changes noted at final follow-up.

Conclusions:

• Resurfacing shoulder arthroplasty can reproduce anatomy and compensate for glenohumeral wear.
• Technical imperfections may lead to varus prosthesis positioning.
• Medialization of the humerus and glenoid wear were observed during follow-up, potentially correlating with pain recurrence.