The accuracy of patient-reported weight prior to total joint arthroplasty and arthroscopy of the lower extremity.

Purpose: The accuracy of preoperative patient-reported weight was never evaluated in patients undergoing lower extremity procedures. The purpose of this study was to: (1) compare the disparity between patient-reported and measured weights in patients undergoing lower extremity total joint arthroplasty (LE-TJA) and arthroscopy; and (2) investigate the association between patient-specific factors (patient age, BMI, zip code, and psychiatric comorbidities) and the accuracy of patient-reported weight.

Methods: Preoperative self-reported weights were retrospectively compared to measured weights in 400 LE-TJA and 85 control arthroscopy patients. The difference between reported and measured weights was calculated. Additionally, the percent of accurate reporting within 0.5, 1, and 5 kg ranges of the measured weight was calculated. Outcomes were compared between surgical modalities as well as between patient-specific factors.

Results: There was low disparity (p = 0.838) between patient-reported and measured weights among LE-TJA (mean difference 0.18 ± 3.63 kg; p = 0.446) and that of arthroscopy (0.27 ± 4.08 kg; p = 0.129) patients. Additionally, LE-TJA patients were equally likely to report weights accurately within 0.5 kg of the measured weight (74% vs. 71.76%; p = 0.908). LE-TJA and arthroscopy patients had similar reporting accuracy within 1 and 5 kg of the measured weights (p > 0.05).

Conclusion: Preoperative patient-reported weights demonstrated acceptable accuracy in both LE-TJA and lower extremity arthroscopic orthopaedic patient populations making it a potentially reliable parameter of preoperative assessment.