Hidden blood loss and related risk factors in arthroscopic rotator cuff repair surgery

A BSTRACT Objectives: As intraoperative blood loss and its potential causes have not been well characterized, the present study aimed to determine the estimated blood loss and related risk factors in arthroscopic rotator cuff repair (ARCR) surgery. Surgical time was hypothesized to be a confounder related to blood loss in this surgery. Materials and Methods: This retrospective cohort study included 72 patients, 49 in the massive rotator cuff tear group and 23 in the single rotator cuff tear group, who underwent ARCR surgery between May 2016 and April 2018. Blood loss was calculated, and potential confounders were investigated. The Mann–Whitney U -test was used for comparing continuous variables, whereas the Chi-square test or Fisher’s exact test was selected for categorical variables. Results: The mean estimated blood loss was 311.8 ± 183 mL (range: 37.1 mL to 796.6 mL). The demographic characteristics were comparable between the single and massive rotator cuff tear groups. Compared with the single rotator cuff tear subgroup, the operative time and number of inserted anchors were significantly greater in the massive rotator cuff tear subgroup ( P < 0.001). Furthermore, the operative time was significantly correlated with estimated blood loss in the massive rotator cuff tear subgroup (β = 1.85, P = 0.037). Conclusion: Our study revealed that blood loss from ARCR surgery was approximately 300 mL. Importantly, we found that operative time was significantly correlated with blood loss in the massive rotator cuff tear subgroup. These findings underscore the need for more clinical attention to be paid to patients diagnosed with massive rotator cuff tears, providing valuable insights for future patient care.