Total Shoulder Arthroplasty Preoperative Pain Threshold and Association With Postoperative Opioid Consumption

Prior to undergoing total shoulder arthroplasty (TSA), it is important to counsel the patient on what the postoperative period will look like. Important factors that patients must consider include recovery time, amount of experienced pain, and risks for complications. A lower preoperative pain level has been shown to be a strong predictor of less postoperative pain, less opioid consumption, and greater patient satisfaction. However, pain is relative and typically quantified on a scale of 1-10. The pressure pain algometer is a tool that allows for the quantification of pain threshold and has demonstrated strong reliability with low inter-observer error. The pressure pain algometer has been used to determine preoperative pain thresholds in previous human studies and has been regarded as a suitable tool for assessing pain. Despite the use of this technique in the current literature, data on the application of this tool in Total Shoulder Arthroplasty (TSA) is lacking. There is no current study that has studied the use of preoperative pain thresholds using a pressure pain algometer and its correlation of patient satisfaction, and opioid consumption in TSA patients. This study will be important in closing the knowledge gap in the current literature and provide a better understanding of the usefulness of assessing preoperative pain thresholds with a pressure pain algometer on determining postoperative patient satisfaction, and opioid consumption in patients undergoing total shoulder arthroplasty.

This is a prospective, non-randomized observational study. There will only be one group, the treatment group, consisting of patients undergoing Total Shoulder Arthroplasty (TSA). The study team will recruit patients using a screen for patients who meet inclusion criteria in the institutional electronic medical record platform, EPIC, or recruit patients via physician referral. Inclusion criteria include all patients over 18 years of age who are undergoing TSA. When an eligible patient is selected, the study team will first obtain approval to approach the patient from the treating physician. Once approval is received, a co-investigator will approach them over the phone to inform the patient about a study he or she is eligible for or approach them in person during their visit. All patient eligibility data will be kept in a secure file that is password protected and secured on the Cooper secure network, in a drive behind a firewall. Only study personnel will have access to this information and the documents.

There will be four visits involved in this study, all of which follow the standard of care visit schedule:

Visit 1 is the consenting visit \& patients will be consented by the study doctors or co-investigators in the clinic. The preoperative pain threshold score will be obtained.

Visit 2 is the surgery visit the patient will undergo all typical procedures as if they were not in the study. Algometer pain scores and all questionnaires (Demographics, The Tobacco, Alcohol, Prescription medications, and other Substance \[TAPS\] 1, Visual Analogue Scale \[VAS\], The 12-item Short Form Survey\[SF-12\], The Single Assessment Numeric Evaluation \[SANE\] ) must be completed by this time, either in person at Visit 1, over the phone, via REDCap , or by email prior to this visit, or in pre-op holding where they will sign official consents. The opioid consumption journal will be given to the patient for the patient to record his or her daily opioid intake immediately following TSA. The study team will ask the patients to record their daily opioid consumption in the journal for the first two weeks. Prior to prescribing any prescription narcotics post-operatively, per standard of care, The study team will utilize the Prescription Monitoring Program (PMP) to determine what prescription narcotics the patient is currently on. With the patient's permission, and on the consent form, The study team will check the patient's PMP at 3 months to record opioid consumption.

Visit 3 is the 2-week follow-up visit post-surgery. The subject's standard of care data points will be obtained at this visit, in addition to the VAS, SF-12, and SANE, again which are strictly for research purposes.

Visit 4 is the 6-week follow-up visit post-surgery. The subject would have this visit even if they were not in the study and the same procedures will be conducted during the visit as standard of care. The subject's standard of care data points will be obtained at this visit, in addition to the VAS, SF-12, and SANE, again which are strictly for research purposes.

Visit 5 is the 3-month follow-up visit post-surgery. The subject would have this visit even if they were not in the study and the same procedures will be conducted during the visit as standard of care. The subject's standard of care data points will be obtained at this visit, in addition to the VAS, SF-12, SANE, and Satisfaction Survey again which is strictly for research purposes. The hard copies of the opioid consumption journal will be collected at the final visit. The study team will not need another algometer pain score post-operative as it has already been established in the pre-operative scores.

The study team will rely on the completion of the questionnaires, opioid consumption journal, and surveys to establish a correlation between pre-operative pain threshold and postoperative outcomes. All Protected Health Information (PHI) will be kept on a secure coded document that is password encrypted and stored on the secure Cooper secure network, in a drive behind a firewall. The rest of the study-specific data will be kept on REDCap, where each patient will have a specific study identifier (ID) that corresponds with their research records. there will be no PHI stored on REDCap.