for people ages 12-99 (full criteria)
at San Francisco, California and other locations
study started
completion around
Principal Investigator
by Benjamin C Ma, MD
Headshot of Benjamin C Ma
Benjamin C Ma



This project will be a multi-center, prospective longitudinal cohort for all patients undergoing primary shoulder instability surgery, excluding isolated SLAP repairs. We will be looking for risk factors for recurrent instability, revision surgery, and poor outcomes. Patients will be asked to complete the RAND-36, ASES, Shoulder Activity, EQ-5D and WOSI outcome measures, as well as demographic and socioeconomic information. Surgeons will complete a form after surgery with information on radiographic findings, physical exam, surgical findings, and the repair. Patients will wear a sling post-operatively, and follow standardized rehabilitation protocols, including physical therapy.

Patients will be sent outcome questionnaires at 2, 6, 10, and 20 years after surgery.


The objective of this prospective multicenter cohort study of patients undergoing surgery for glenohumeral instability is to identify the outcomes, and more importantly, the previously unknown predictors of sports function, activity level, general health, recurrent instability symptoms, and surgical failures following surgery. Patient information at the time of the surgery (demographics, validated outcome measures), in addition to the physical exam findings, shoulder pathology at the time of surgery, and surgical treatment will be obtained. The validated outcome instruments are American Shoulder and Elbow Surgeons Score, Western Ontario Shoulder Instability, Kerlan Jobe Overhand Athlete Score, Shoulder Activity Score, and RAND-36. Post-operative physical exam data will be obtained at 6 months after surgery. Patient reported outcomes will be repeated at 2, 6, 10, and 20 years post-operatively. Our multivariable analysis will identify which of the many factors related to the injury, intra-operative treatment, postoperative care, physical patient characteristics, and behavioral patient characteristics contribute to recurrence and poor outcome.


Other Instability, Shoulder, Dislocations, Subluxations, Recurrent Dislocation of Shoulder Region, instability, Joint Dislocations, Shoulder Dislocation, MOON Shoulder Instability


You can join if…

Open to people ages 12-99

This is a prospective cohort study; there is no control group. Subjects that are included are all patients undergoing surgery for shoulder instability.

Inclusion criteria:

  • Anterior, posterior, and inferior instability
  • Ages 12-99
  • Open and arthroscopic repair
  • Revision of a previous shoulder instability repair
  • Latarjet/bone augmentation

You CAN'T join if...

  • Workers compensation patients
  • Prisoners
  • Non-English speaker
  • Not mentally competent
  • Unable/unwilling to return for clinical follow-up
  • Arthroplasty patients
  • Rotator cuff tears
  • Fractures


  • UCSF Orthopedic Institute accepting new patients
    San Francisco California 94158 United States
  • University of Colorado accepting new patients
    Boulder Colorado 80304 United States

Lead Scientist at UCSF

  • Benjamin C Ma, MD
    Dr. C. Benjamin Ma is Chair of the UCSF Department of Orthopaedic Surgery as well as a Professor in Residence in Sports Medicine and Shoulder Surgery. He specializes in sports medicine, arthroscopic shoulder surgeries to repair rotator cuff tears and ligament instability, shoulder replacement, knee ligament reconstruction, and procedures to address meniscus and other cartilage injuries.


accepting new patients
Start Date
Completion Date
Carolyn M Hettrich
Study Type
Observational [Patient Registry]
Expecting 2500 study participants
Last Updated