In the JournalsPerspective

Non-spherical shoulder arthroplasty yielded clinical benefits for glenohumeral arthritis

Patients with primary glenohumeral arthritis and either concentric or non-concentric glenoids experienced excellent clinical benefits when treated with non-spherical shoulder arthroplasty with an inlay glenoid replacement, according to published results.

In a retrospective case series, Anthony Miniaci, MD, and colleagues collected the Penn Shoulder Score, VAS score for pain, range of motion, radiographic analysis and complications among 29 patients with primary glenohumeral arthritis, intact rotator cuffs and no prior open shoulder surgeries treated with a combination of non-spherical humeral head resurfacing and inlay glenoid replacements (HemiCap OVO/Inlay Glenoid Total Shoulder System; Arthrosurface).

Results showed no statistically significant differences in Penn Shoulder Score domains, including pain, function, satisfaction and total score; forward flexion, external rotation and VAS score for pain between concentric (n=7) and non-concentric (n=24) glenoids. Researchers found a mean Penn Shoulder Score of 25.3 for pain, 52.7 for function and 8.4 for satisfaction and a total score of 87. Patients had a mean forward flexion of 167.3°, external rotation of 56.6° and VAS for pain of 0.9, according to results. Researchers noted no signs of periprosthetic fracture, component loosening, osteolysis or hardware failure, and no patients required revision or 90-day rehospitalization.

Based on these results, Miniaci said non-spherical shoulder arthroplasty with inlay glenoid replacement may be a less invasive solution for treatment of glenohumeral arthritis in patients with an intact rotator cuff and no prior open shoulder surgeries.

“What we have done is we have changed the biomechanics to make it a more favorable situation so that these patients not only have better function, but ... the biomechanics would suggest that, because of the stress reduction on both sides of the joint, this type of construct would be better for ... younger active patients who have arthritis in their shoulder,” Miniaci told Healio.com/Orthopedics. – by Casey Tingle

Disclosure: Miniaci reports consulting fees and royalties from Arthrosurface.

Patients with primary glenohumeral arthritis and either concentric or non-concentric glenoids experienced excellent clinical benefits when treated with non-spherical shoulder arthroplasty with an inlay glenoid replacement, according to published results.

In a retrospective case series, Anthony Miniaci, MD, and colleagues collected the Penn Shoulder Score, VAS score for pain, range of motion, radiographic analysis and complications among 29 patients with primary glenohumeral arthritis, intact rotator cuffs and no prior open shoulder surgeries treated with a combination of non-spherical humeral head resurfacing and inlay glenoid replacements (HemiCap OVO/Inlay Glenoid Total Shoulder System; Arthrosurface).

Results showed no statistically significant differences in Penn Shoulder Score domains, including pain, function, satisfaction and total score; forward flexion, external rotation and VAS score for pain between concentric (n=7) and non-concentric (n=24) glenoids. Researchers found a mean Penn Shoulder Score of 25.3 for pain, 52.7 for function and 8.4 for satisfaction and a total score of 87. Patients had a mean forward flexion of 167.3°, external rotation of 56.6° and VAS for pain of 0.9, according to results. Researchers noted no signs of periprosthetic fracture, component loosening, osteolysis or hardware failure, and no patients required revision or 90-day rehospitalization.

Based on these results, Miniaci said non-spherical shoulder arthroplasty with inlay glenoid replacement may be a less invasive solution for treatment of glenohumeral arthritis in patients with an intact rotator cuff and no prior open shoulder surgeries.

“What we have done is we have changed the biomechanics to make it a more favorable situation so that these patients not only have better function, but ... the biomechanics would suggest that, because of the stress reduction on both sides of the joint, this type of construct would be better for ... younger active patients who have arthritis in their shoulder,” Miniaci told Healio.com/Orthopedics. – by Casey Tingle

Disclosure: Miniaci reports consulting fees and royalties from Arthrosurface.

    Perspective

    Anatomic total shoulder arthroplasty in young active patients with advanced glenohumeral arthritis remains a challenge because of concerns about patient demands and expectations. Implants should be selected for durability, revisability and long-term shoulder mobility and function.

    In their study, Anthony C. Egger, MD, and his colleagues report on the results of total shoulder arthroplasty employing a non-spherical humeral head resurfacing, narrower from anterior to posterior, and an inlay glenoid component inserted off-axis. A non-spherical humeral component has the potential for more normal kinematics and joint loading, and an inlay glenoid component has advantages including resistance to shear forces and subchondral bone conservation, especially in cases of posterior glenoid wear.

    The authors demonstrate excellent clinical results and recovery of near full active forward elevation and external rotation, but some questions remain unanswered. Their use of a humeral head resurfacing preserves subchondral bone but complicates glenoid exposure so the authors should have included some pearls for improving glenoid exposure. The inlay glenoid resurfaces only a portion of the glenoid, raising questions about the potential for additional posterior wear over time. The postoperative shoulder range of motion attained in this study is superior to that in studies of conventional stemless total shoulder arthroplasty but preoperative range of motion was also greater, so that the improvement in shoulder mobility (effectiveness) is similar. Finally, the minimum 24 months follow-up is too short to draw strong conclusions. As such, this study demonstrates feasibility rather than equivalency or superiority and longer follow-up is critical to establish this technique as an option for treating the young patients with advanced primary osteoarthritis of the glenohumeral joint.

    • Samer S. Hasan, MD, PhD
    • Mercy Health/Cincinnati Sports Medicine and Orthopaedic Center
      Chief of surgery and orthopedics
      The Jewish Hospital
      Cincinnati

    Disclosures: Hasan reports he is a consultant for and receives royalties from DJO Inc. and is a speaker for Arthrex.

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