The purpose of the study is to see if there is a connection between a proximal humerus fracture dislocation direction and the likelihood of developing avascular necrosis. Utilizing a retrospective cohort from the last ten years we hope to bring consenting patients back for a single visit to have x-rays and complete patient reported outcome measures to assess for evidence of avascular necrosis.

The incidence of proximal humerus fractures continues to increase and is among one of the more common fractures seen in the adult population. Proximal humerus fracture dislocations, however, are less common. Despite the decreased prevalence, fracture dislocations have unique challenges with respect to obtaining an anatomical reduction and more frequently involve an open surgical reduction. In addition, depending on other fracture characteristics, there are various treatment options for the fracture itself. While fracture dislocations ultimately lead to increased AVN and revision surgery, further discussion surrounding the direction of dislocation and how it may influence overall outcomes has not been addressed in the previous literature. The study design utilizes a retrospective cohort from the last ten years, by asking patients who have had a previously surgically treated proximal humerus fracture dislocations to come back to the surgeon's private clinic to complete a single visit assessment. During this assessment the consenting participant will receive x-rays and complete patient reported outcome measures. In conjunction, these will be utilized to assess overall function and the existence of avascular necrosis.

Inclusion Criteria:

• Patients 18 years of age or older
• Patients who underwent operative fixation of proximal humerus fracture dislocation at Royal Columbian Hospital between January 2011 and July 2021
• Willing and able to consent and complete patient reported outcome measures
• Willing and able to follow the protocol and attend a follow-up visit
• Able to read and understand English or have an interpreter available

Exclusion Criteria:

• Skeletally immature patients
• Patient with pathological fractures
• Patients who have had previous operative fixation of proximal humerus
• Patients treated non-operatively
• patients presenting outside of the study duration window
• Patients treated by a non-participating surgeon
• Deceased patients
• Patients unable to complete patient reported outcome measures
• Patients declining to come back to the clinic for updated x-rays
• Dementia
• Incarceration

Skeletally mature patients who were surgically treated for their proximal humerus fracture dislocation between 2011 and 2021.

There is currently no plan to share individual participant data with other researchers, results will of course be shared. However, the hope is that the study might indicate a need for a high powered prospective clinical trial to be completed.