Patient-Reported and Objectively Measured Function Before and After Reverse Shoulder Arthroplasty.

BACKGROUND AND PURPOSE

Documenting functional outcomes after reverse shoulder arthroplasty (RSA) is critical to advancing patient care. The interplay been self-reported and objectively measured outcome measures has not been widely described. The utilization of wearable devices to document upper extremity limb activity is a new approach for objectively measuring outcomes. Therefore, the purpose of this study was to evaluate changes in pain, and self-reported function and objectively measured limb activity after RSA. We also assessed the influence of pain on self-reported function and objectively measured limb activity to determine the impact of pain on outcomes after RSA.

MATERIALS

This study implemented a prospective, repeated-measures design. Fourteen patients undergoing RSA underwent testing before surgery, and 2 and 12 months after surgery. Patient-reported instruments included pain, Disabilities of Arm, Shoulder and hands (DASH), and physical component summary (PCS) of the 36-Item Short Form Health Survey. Objective limb activity (mean activity value, m/s/min epoch; inactive time, %; low activity, %; and high activity, %) was captured with triaxial accelerometers worn on the upper and lower arm. A repeated-measures ANOVA tested for differences across time. The Spearman rank-order correlation was calculated to evaluate the influence of pain on DASH, PCS scores, and mean limb activity.

RESULTS

Patient-reported measures improved after surgery (pain, P < .01; DASH, P < .01; PCS, P = .01). No change in limb activity was found at 1 year compared with preoperative values for mean (forearm, P = 1.00; arm, P = .36), inactivity (forearm, P = .33; arm, P = .22), low (forearm, P = .77; arm, P = .11) or high (forearm, P = 1.00; arm, P = .20) activity. There was a relationship between pain and DASH scores 1 year after surgery (P = .04) but not before surgery (P = .16), or 2 months after surgery (P = .30). There was no relationship between pain and PCS scores at any time point (preoperative, P = .97; 2 months, P = .21; 1 year, P = .08) nor pain and limb activity (forearm: preoperative, P = .36; 2 months, P = .67; 1 year, P = .16; arm: preoperative, P = .97; 2 months, P = .59; 1 year, P = .51).

CONCLUSIONS

RSA reduced pain and enhanced patient-perceived function. Objectively measured upper extremity limb activity is not different 1 year after surgery compared with preoperative levels.

LEVEL OF EVIDENCE

III.