Background: The Frequency, Etiology, Direction, and Severity (FEDS) system was developed as a simple but reliable method for classifying shoulder instability based on 4 factors attainable by history and physical examination: frequency (solitary, occasional, or frequent); etiology (traumatic or atraumatic); direction (anterior, posterior, or inferior); and severity (subluxation or dislocation). This study investigated the epidemiology and 2-year surgical outcomes for the FEDS categories in the prospective Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort. Methods: At the time of surgery, 1204 patients were assigned to the FEDS categories. Follow-up data were available for 636 of 734 patients (86.6%) who had undergone surgery at least 2 years prior to analysis. The most common categories were further analyzed by patient-reported outcomes (PROs) (American Shoulder and Elbow Surgeons, Western Ontario Shoulder Instability index, Single Assessment Numeric Evaluation scores) and rates of recurrent subluxation, recurrent dislocation, and revision surgery. Results: Of the 36 FEDS categories, 16 represented at least 1% of patients. Occasional traumatic anterior dislocation (OTAD) was the most common category, with 16.4% of patients. Five other anterior categories (solitary traumatic anterior subluxation, occasional traumatic anterior subluxation [OTAS], frequent traumatic anterior subluxation [FTAS], solitary traumatic anterior dislocation, and frequent traumatic anterior dislocation) and one posterior category (solitary traumatic posterior subluxation [STPS]) represented at least 5% of patients. PROs improved significantly for each category. The highest rates of recurrent subluxation occurred in FTAS, OTAS, and OTAD cases; dislocation, OTAS and FTAS cases; and further surgery, OTAD cases. The lowest rates of failure occurred in STPS cases. Downward trends in PROs and higher failure rates were noted with an increasing number of preoperative dislocations. Conclusion: Different FEDS categories showed varying degrees of improvement and failure rates, indicating that the system can be used to provide prognostic insight for presurgical education. Overall, outcomes decreased with a higher number of preoperative dislocations.
|Number of pages||10|
|Journal||Journal of Shoulder and Elbow Surgery|
|State||Published - Apr 2020|
Bibliographical noteFunding Information:
The MOON Shoulder Instability cohort is supported by the Orthopaedic Research and Education Foundation . This study was supported in part by research grants from the Orthopaedic Research & Education Fund (grant 14-003 ) and by the National Center for Advancing Translational Sciences ( UL1TR001998 ) and the Dean of the College of Medicine, University of Kentucky . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health (NIH) or the University of Kentucky. The REDCap (Research Electronic Data Capture) database at Vanderbilt University in Nashville, Tennessee, was used for data collection.
Rick W. Wright serves on the boards of directors of the American Board of Orthopaedic Surgery and American Orthopaedic Association, which are not paid board positions. His institution receives research grant money from the NIH and National Institute of Arthritis and Musculoskeletal and Skin Diseases unrelated to the submitted work. He receives book royalties from Wolters Kluwer and Lippincott, Williams & Wilkins. He receives travel reimbursements when traveling with the St Louis Blues Hockey Club as the team physician, which is outside the submitted work.
Eric C. McCarty consults for Zimmer Biomet. He receives grant money from Smith & Nephew, Arthrex, and DePuy for fellowship support unrelated to this project; receives money for patents unrelated to the submitted work; and receives royalties from Elsevier.
The MOON Shoulder Instability cohort is supported by the Orthopaedic Research and Education Foundation. This study was supported in part by research grants from the Orthopaedic Research & Education Fund (grant 14-003) and by the National Center for Advancing Translational Sciences (UL1TR001998) and the Dean of the College of Medicine, University of Kentucky. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health (NIH) or the University of Kentucky. The REDCap (Research Electronic Data Capture) database at Vanderbilt University in Nashville, Tennessee, was used for data collection. MOON Shoulder Group collaborators: Keith M. Baumgarten, MDe, Julie Y. Bishop, MDf, Matthew J. Bollier, MDg, Jonathan T. Bravman, MDh, Robert H. Brophy, MDi, Charles L. Cox, MD, MPHj, Brian T. Feeley, MDk, John A. Grant, MD, PhDl, Grant L. Jones, MDf, C. Benjamin Ma, MDk, Robert G. Marx, MD, MScm, Eric C. McCarty, MDh, Bruce S. Miller, MD, MSl, Matthew V. Smith, MDi, Rick W. Wright, MDj, Alan L. Zhang, MDk. eOrthopedic Institute, Sioux Falls, SD, USA; fThe Ohio State University Sports Medicine Center, Columbus, OH, USA; gUniversity of Iowa Hospitals and Clinics, Iowa City, IA, USA; hDepartment of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA; iDepartment of Orthopedics, Washington University Saint Louis, St Louis, MO, USA; jDepartment of Orthopaedic Surgery and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN, USA; kDepartment of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA; lMedSport, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA; mDepartment of Sports Medicine, Hospital for Special Surgery, New York, NY, USA.
Brian R. Wolf's institution received an Orthopaedic Research and Education Foundation grant for this study. He is a paid board member of United HealthCare and is a consultant for ConMed and SportsMed Innovate. His institution received educational grant money from ConMed, Smith & Nephew, and Arthrex unrelated to the submitted work.
© 2019 Journal of Shoulder and Elbow Surgery Board of Trustees
- FEDS classification
- Level II
- Prospective Cohort Design
- Treatment Study
ASJC Scopus subject areas
- Orthopedics and Sports Medicine