Impact of Glenosphere Size on Range of Motion in Female Patients Undergoing Reverse Shoulder Arthroplasty

Impact of Glenosphere Size on Range of Motion in Female Patients Undergoing Reverse Shoulder Arthroplasty

Impact of Glenosphere Size on Range of Motion in Female Patients Undergoing Reverse Shoulder Arthroplasty

The purpose of this study is to perform a prospective randomized trial among female patients undergoing reverse shoulder arthroplasty (RSA) to determine if a larger glenosphere allows greater range of motion without an impact on complications.

A current research debate is whether glenosphere size has a significant clinical impact on a patient's range of motion (ROM) following RSA. Some researchers have shown an association between increased glenosphere size and improved ROM, but no study has determined the absolute minimal motion differences that would be recognizable or beneficial by patients. This is mostly attributable to limitations such as small sample sizes as well as the fact that shoulder dynamics are multifactorial in nature. Most studies have shown an increased ROM with larger glenosphere sizes.1 Because smaller patients are often times female and receive smaller implants, female patients may be more susceptible to limited ROM. The purpose of this study is to determine if a larger glenosphere allows for greater ROM in female patients undergoing RSA.

This study is a randomized trial consisting of female patients undergoing reverse shoulder arthroplasty for rotator cuff tear arthropathy or a massive irreparable rotator cuff tear. The experimental group will receive a 36mm glenosphere and the control group will receive the standard 32mm glenosphere. All other conditions of the surgical procedure will be identical as well as the clinical follow-up.

Two randomized study groups will be formed with the consented patients (experimental and control). All patients will undergo reverse shoulder arthroplasty by the Principal Investigator. The experimental group patients will receive a 36mm glenosphere and the control group will receive a 32mm glenosphere. All other procedures during the surgery are identical between groups.

Standard functional outcomes questionnaire following shoulder surgery, range 0 - 100 (highest function)

Standard functional outcomes questionnaire following shoulder surgery, range 0 - 100 (highest function)

Inclusion Criteria: Female sex Diagnosis of rotator cuff tear arthropathy or a massive irreparable rotator cuff tear for which the patient has elected to undergo reverse shoulder arthroplasty No history of prior shoulder arthroplasty Consent to study participation by signing the informed consent and the Protected Health Information (PHI) form (Attachment B and C) Ability to speak, read and write English Exclusion Criteria: Male sex Any impairment that would prevent answering the surveys No children or adolescents under the age of 18 years old No prisoners, pregnant women, or mentally disabled persons No Workers' Compensation cases

Mollon B, Mahure SA, Roche CP, Zuckerman JD. Impact of glenosphere size on clinical outcomes after reverse total shoulder arthroplasty: an analysis of 297 shoulders. J Shoulder Elbow Surg. 2016 May;25(5):763-71. doi: 10.1016/j.jse.2015.10.027. Epub 2016 Feb 4.